Colorimetric parameters correlated with the variation in the marker constituent contents during the stir-fry processing of Schizonepetae Spica

Colorimetric parameters correlated with the variation in the marker constituent contents during the stir-fry processing of Schizonepetae Spica | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Colorimetric parameters correlated with the variation in the marker constituent contents during the stir-fry processing of Schizonepetae Spica Xindan Liu, Ying Zhang, Menghua Wu, Zhiguo Ma, Hui Cao This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-414931/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 13 Jan, 2022 Read the published version in Food Analytical Methods → Version 1 posted You are reading this latest preprint version Abstract Background: Color is an important method of authentication to evaluate the degree of Chinese medicinal material (CMM) processing. This traditional color description used for identification needs to be confirmed by modern scientific analysis. Schizonepetae Spica (SS), the dried spike of Schizonepeta tenuifolia Briq., is a traditional Chinese medicinal herb. Raw SS has the actions of dispelling the common cold and fever. Schizonepetae Spica Carbonisata (SSC; raw SS processed by stir-frying until the surface becomes blackish-brown and the interior turns dark yellow) has particularly strong efficacy in arresting bleeding from bloody stool and metrorrhagia. Methods: In this paper, a high-performance liquid chromatography-diode array detector method and colorimetry were employed to determine 6 nonvolatile marker constituents and the color parameters ( L * , a * and b * ) of SS during stir-fry processing, respectively. Results: According to Pearson correlation analysis, L * , a * and b * showed significant correlations with the levels of luteolin-7-O- β -D-glucoside, apigenin-7-O- β -D-glucoside, hesperidin and rosmarinic acid, while a * was significantly correlated with the amounts of luteolin and apigenin. The corresponding regression models were good fits for the color parameters as respective functions of the 6 marker constituents according to enter multiple linear regression and third-order polynomial curve fitting methods (adjusted R 2 > 0.800). Conclusion: Surrogate prediction of marker compounds using color parameters provides a valuable and cost-saving tool for rapid or online monitoring of the processing degree of SS. Raw SS and SSC could be determined based on the color parameters and 6 marker constituent contents for a comprehensive quality evaluation for the first time. This paper provides scientific data to validate the relationships between color features and quality during the processing of SS. Materials Chemistry Color identification Schizonepetae Spica Stir-fry processing Correlation analysis Regression analysis Figures Figure 1 Figure 2 Background Chinese medicinal materials (CMMs) often have to be processed by using physical or chemical treatment before prescription or clinical usage. The aims of processing are to alter the clinical efficacy and/or reduce the toxicity of CMMs to fulfill the different requirements of therapy [ 1 ]. There is a close relationship between the efficacy, safety and processing of CMMs. Improper processing methods may produce poor clinical effects or even result in poisoning [ 2 ]. Characteristics of CMMs such as color are usually used to assess the degree of processing. For example, when dry Zingiberis Rhizoma is roasted with sand until it becomes brown externally, it is called Zingiberis Rhizoma Praeparatum. Cirsii Japonici Herba is called Cirsii Japonici Herba Carbonisata when it is stir-fried until the surface becomes black. However, this approach often depends to a certain extent on the practitioner’s experience, which is strongly subjective and lacks objective criteria, so modern scientific analytical techniques are needed to confirm the validity of associations between the color and processing degree of CMMs. Schizonepetae Spica (SS) is the dried spike of Schizonepeta tenuifolia Briq. (Chinese Pharmacopoeia, 2020 edition) [ 3 ]. It was first recorded in Shen Nong Ben Cao Jing (Shen Nong’s herbal classic), a book written 2000 years ago [ 4 ]. Chemical studies revealed that SS contains volatile oils, flavonoids, organic acids and so on [ 5 – 7 ]. Pharmacological analyses have shown that SS has three main biological properties, namely, anti-inflammatory [ 8 ], antiviral [ 9 , 10 ], and hemostatic activity [ 11 – 13 ]. The essential oils of SS are recognized as the major constituents responsible for its anti-inflammatory and antiviral effects [ 8 , 14 ]. In addition, the nonvolatile compounds such as flavonoids and organic acids from SS exhibit various biological activities. For example, luteolin-7-O- β -D-glucoside has been demonstrated to have good biological activity in terms of anti-inflammatory and antiviral effects [ 15 , 16 ]. Apigenin-7-O- β -D-glucoside, hesperidin and luteolin have also been documented to possess significant antiviral activity [ 5 , 17 , 18 ]. Moreover, luteolin has been shown to be a potent hemostatic drug candidate [ 19 ]. Rosmarinic acid exhibits many biological properties, including antioxidant, antibacterial, anti-inflammatory and antiallergic effects [ 20 ]. Apigenin has notable anticancer activity in vitro and in vivo [ 21 ]. Thus, the contents of flavonoids and organic acids could be used as evaluation markers for SS. The herb is commonly used in traditional Chinese medicine (TCM) prescriptions to treat the common cold, fever, bloody stool and metrorrhagia [ 22 ]. To treat the common cold and fever, TCM practitioners often prescribe raw SS, while to treat bloody stool and metrorrhagia, they usually use Schizonepetae Spica Carbonisata (SSC; raw SS processed by stir-frying until the surface becomes blackish-brown and the interior turns dark yellow) [ 3 ]. However, the quality control standards of processing practices are inconsistent in terms of the national standard and various local standards. For example, the processing method “stir-frying until the surface becomes blackish-brown and the interior turns dark yellow” is recorded in the Chinese Pharmacopoeia (2020 edition), while stir-frying until the surface becomes dark brown and the interior turns brown is recorded in “The Practices of Processing Chinese Crude Drugs in Jiangsu Province” [ 23 ]. In addition, color discrimination of SSC is mainly based on the experience of individual operators. To guarantee the quality of SSC, a standardized processing method is critical. Therefore, the above problems of “SS with several processing methods and differences in different areas” should be harmonized, and consistent practices based on modern scientific studies need to be established. In recent years, advances in sensor technologies such as colorimeters, electronic noses and electronic tongues have provided signals related to sensory attributes, making it easier to objectively characterize the color, aroma and taste of various products. Some studies have reported the use of a colorimeter to substitute the traditional color discrimination of CMMs [ 24 , 25 ]. The colorimeter technique can be used to measure processed CMM products, with the additional advantage of controlling the technological parameters. Both colorimetry techniques and modern analytical techniques should be combined to map marker components in order to evaluate the scientific elucidation of color discrimination behind processing procedures and the quality of processing. Therefore, the main purposes of this study were to investigate the relationship between chromatic aberrations and content variations in the marker nonvolatile substances of SS during processing in order to clarify the core scientific elucidation of color as an important indicator of the degree of processing. For this purpose, first, HPLC coupled with a diode array detector (DAD) was used to evaluate five flavonoids and one organic acid of SS during stir-fry processing, and the powder color was simultaneously determined using a colorimeter. Second, the correlations between marker constituents and chromatism were investigated by Pearson correlation analysis. Finally, polynomial regression models were established with the color parameters to rapidly predict the contents of the marker constituents. This was the first study to develop a method for the quantitative analysis of nonvolatile ingredients of SS using color parameters during stir-fry processing. Materials And Methods Materials and reagents Raw SS, originating from Henan Province (China), was provided by Hexiang Pharmaceutical Co. Ltd., and authenticated in accordance with the SS monograph in the Chinese Pharmacopoeia (2020 edition) by Dr. Ying Zhang, Jinan University, P. R. China. The voucher specimen (No. HX18C01) was deposited at the Research Center for Traditional Chinese Medicine of Lingnan (Southern China), Jinan University. Acetonitrile (HPLC grade), methanol (HPLC grade) and formic acid (HPLC grade) were purchased from Fisher Scientific (Fair Lawn, NJ, USA). The chemical standards luteolin-7-O- β -D-glucoside (No. M-025-190115), hesperidin (No. C-006-180216), rosmarinic acid (No. 190921), luteolin (No. M-007-181216) and apigenin (No. Q-002-180131) were supplied by Chengdu Ruifensi Biotechnology (Sichuan, China). Apigenin-7-O- β -D-glucoside (No. T4S0295) was acquired from Tianjun Biotechnology (Guangzhou, China). The purity of the compounds was greater than 95%, as detected by HPLC-DAD. Deionized water was purified by passing distilled water through a Milli-Q purification system (Millipore, Bedford, MA, USA). All other chemical reagents were of analytical grade. Sample preparation Ten grams of dried SS slices (10–15 mm in length) were placed in a pan and stir-fried at different temperatures (240°C ± 10°C, 300°C ± 10°C, and 360°C ± 10°C) for 5, 5.5, 6, 6.5, 7 and 7.5 min. Thus, we prepared 18 batches of SSC samples, and then, we determined the contents of the marker constituents and the color parameters in each batch of the prepared SSC samples as well as the raw SS. Quantitative analysis of the main chemical ingredient content of SS and SSC samples The SS and SSC samples were ground and filtered through a 24-mesh sieve. The powder (2 g) was weighed accurately and macerated in 20 mL of 75% ethanol. Then, the sample was extracted for 60 min by hot reflux extraction in a water bath. A 10 µL supernatant of the extracts was injected for HPLC analysis after filtration with a 0.45-µm membrane. An UltiMate 3000 liquid chromatography system (Thermo Scientific, Bremen, Germany) equipped with a diode array detector and an ACE Excel 5 C18 column (4.6 mm ×250 mm, 5 µm; ACE, Scotland, UK) was used throughout this study. The mobile phase consisted of A (0.1% formic acid aqueous solution) and B (acetonitrile) using a gradient elution of 8%-20% B from 0–20 min, 20% B holding from 20–30 min, 20%-30% B from 30–50 min, and 30%-8% B from 50–60 min. The column temperature, flow rate, detection wavelength and injection volume were 30°C, 1 mL/min, 283 nm and 10 µL, respectively. The stock solution of the mixture of the 6 marker components was prepared by dissolving the standards in methanol in a 25 mL volumetric flask. A series of appropriate concentrations were analyzed in triplicate to establish the calibration curve. The LODs and LOQs were determined as 3 and 10 times the signal-to-noise (S/N) ratios, respectively. The interday and intraday precisions were determined by analyzing the stock standard solution containing the 6 components, with six repetitions daily over three consecutive days. Six different working solutions prepared from the same sample were analyzed to confirm the repeatability. The same sample was tested at 0, 2, 4, 8, 12, 16, 20, and 24 h to confirm the stability. The recovery was determined by adding three concentration levels (80%, 100% and 120%) of the mixed standard solutions to known amounts of sample. Then, the fortified samples were extracted and analyzed by the proposed method. The mean recoveries were estimated using the following formula: recovery (%) = (amount found – original amount) / amount spiked × 100%. Color measurement The SS and SSC samples were ground and filtered through an 80-mesh sieve to ensure the uniformity of the particles. The color measurement was performed by a CR-410 colorimeter (Konica Minolta, Japan). A Fluke-63 portable infrared thermometer (Fluke, USA) was used to determine the temperature. The SS and SSC samples were filled into a powder box and observed under a D65 light source. The measuring diameter was set at 50 mm with a standard viewing angle of 2 degrees. The International Commission on Illumination (CIE) system was adopted for color quantization, with the chroma space represented by L * , a * and b * . L * represents the brightness from black to white, a * represents the red-green axis, and b * represents the yellow-blue axis. Statistical analysis The correlation between the contents of 6 main marker constituents and the color parameters was analyzed by Pearson correlation analysis. Multiple linear regression models and third-order polynomial functions for the marker components and the color parameters were established by using the enter linear regression method and curve fitting with a polynomial model. The data analysis of variables using Pearson correlation analysis, multiple linear regression analysis (enter) and third-order polynomial curve fitting were performed using SPSS 20.0 software (IBM Inc., USA). Results And Discussion HPLC method validation Validation of the HPLC method was conducted by following the recommendation in the literature [ 26 , 27 ]. The 6 marker compounds of SS and SSC were identified using reference standards of luteolin-7-O- β -D-glucoside, apigenin-7-O- β -D-glucoside, hesperidin, rosmarinic acid, luteolin and apigenin, as well as comparisons with the literature [ 26 , 28 , 29 ]. The proposed HPLC method was validated by determining the linearity, LOD, LOQ, inter- and intraday precisions, repeatability, stability, and recoveries. The equations, linear ranges, LODs and LOQs for the 6 marker compounds are summarized in Table 1 . The intra- and interday RSDs were 0.03%-0.50% and 0.22%-0.73%, respectively (Table 2 ). To confirm the repeatability, six parallel ethanol extracts of SS were analyzed. The RSDs of the 6 marker components detected were 0.56%-2.34%. The RSD values of the HPLC stability test were found to be less than 3.0% (Table 2 ). The measured recoveries of 6 marker compounds ranged from 95.47–104.54%, with an RSD between 0.13% and 2.91%. All these results demonstrated that the developed HPLC method was suitable for the analysis of the constituents in SS and SSC samples. Table 1 Calibration data for the 6 marker compounds by HPLC Compound Regression equation R 2 Linear range (µg/mL) LOD a (µg/mL) LOQ b (µg/mL) Luteolin-7-O- β -D-glucoside y c = 0.1497 x d + 0.2286 0.9992 0.80-159.20 0.29 0.97 Apigenin-7-O- β -D-glucoside y = 0.2128 x + 0.0483 0.9999 0.48-48.00 0.37 1.24 Hesperidin y = 0.1912 x – 0.4667 0.9999 3.08–616.00 0.30 0.98 Rosmarinic acid y = 0.2063 x − 0.2390 0.9999 1.62–324.00 0.26 0.87 Luteolin y = 0.1966 x + 0.1069 0.9998 0.47–141.60 0.10 0.34 Apigenin y = 0.3038 x − 0.0788 0.9999 0.40–120.00 0.08 0.27 a Limit of detection b Limit of quantification c Peak area d Amount of injected compound (µg/mL) Table 2 Precision, repeatability, stability and recovery data for the 6 marker compounds by HPLC Compound Precision (RSD, %) Repeatability (RSD, %, n = 6) Stability (RSD, %, n = 6) Recovery ( n = 3) Intraday ( n = 6) Interday ( n = 3) Mean (%) RSD (%) Luteolin-7-O- β -D-glucoside 0.03 0.28 1.77 2.76 98.52 0.72 101.94 1.07 100.24 1.80 Apigenin-7-O- β -D-glucoside 0.06 0.24 1.46 2.59 95.47 0.35 97.35 0.50 96.18 1.52 Hesperidin 0.09 0.44 0.56 0.28 104.54 0.36 104.72 1.06 101.17 1.81 Rosmarinic acid 0.04 0.22 0.93 1.29 102.92 0.13 103.54 0.87 100.54 1.71 Luteolin 0.09 0.65 0.57 2.79 100.97 0.90 102.40 0.31 99.35 2.91 Apigenin 0.50 0.73 2.34 0.79 99.18 1.25 102.07 2.57 99.47 1.55 Changes in marker compounds during the stir-fry processing of Schizonepetae Spica under different treatment conditions The developed method was applied to simultaneously determine the amount of 6 marker compounds during the stir-fry processing of SS at different temperatures over time. Representative HPLC chromatograms of the standard analytes and the samples are shown in Fig. 1 . Comparison of the chromatograms of samples at various stir-fry temperatures revealed that the contents of four major ingredients (luteolin-7-O- β -D-glucoside, apigenin-7-O- β -D-glucoside, hesperidin and rosmarinic acid) decreased with increasing temperature, whereas the levels of another two main components (luteolin and apigenin) first increased and then progressively decreased with increasing processing temperature. The quantitative results showed remarkable variation among different samples in the contents of the 6 marker compounds (Table 3 and Fig. 2 ). The amounts of luteolin-7-O- β -D-glucoside, apigenin-7-O- β -D-glucoside, hesperidin and rosmarinic acid in the samples derived from the three different processing temperatures decreased with increasing processing time. In contrast, the amounts of luteolin and apigenin initially increased until they reached a plateau and decreased with time in all three cases. In the current study, the contents of these 6 marker compounds fluctuated slightly among different time points, which might be attributed to inhomogeneous stir-fry processing [ 24 , 30 ]. Our recent study showed that the increased levels of luteolin and apigenin might result from the degradation of the glucosidic bond of luteolin-7-O- β -D-glucoside and apigenin-7-O- β -D-glucoside under high-temperature during stir-fry processing [ 31 ]. In general, the amounts of the 6 major constituents decreased gradually with the processing temperature over time. The occurrence of splitting decomposition or cracking of the chemical structures during the heating process may account for these declining phenomena. Table 3 Contents of 6 marker constituents of Schizonepetae Spica samples during stir-fry processing at different temperatures over time No. Heating temperature (°C) Heating time (min) Contents of flavonoids and phenolic acid (mg/g, n = 2) Luteolin-7-O- β -D-glucoside Apigenin-7-O- β -D-glucoside Hesperidin Rosmarinic acid Luteolin Apigenin 1 0 0 0.38 0.26 2.06 0.97 0.10 0.02 2 240 ± 10 5 0.16 0.14 1.67 0.71 0.25 0.21 3 5.5 0.14 0.12 1.37 0.62 0.30 0.20 4 6 0.12 0.11 1.27 0.60 0.34 0.20 5 6.5 0.12 0.10 1.28 0.65 0.35 0.21 6 7 0.10 0.09 1.11 0.60 0.36 0.19 7 7.5 0.10 0.09 1.21 0.63 0.35 0.20 8 300 ± 10 5 0.05 0.03 0.66 0.39 0.28 0.12 9 5.5 0.03 0.01 0.41 0.25 0.25 0.08 10 6 0.03 0.01 0.51 0.29 0.23 0.10 11 6.5 0.03 0.01 0.39 0.24 0.20 0.08 12 7 0.01 - a 0.20 0.12 0.15 0.05 13 7.5 0.02 - 0.32 0.18 0.17 0.07 14 360 ± 10 5 0.05 0.04 0.81 0.31 0.12 0.07 15 5.5 0.06 0.04 0.87 0.32 0.11 0.06 16 6 0.04 0.03 0.71 0.26 0.09 0.06 17 6.5 0.01 - 0.21 0.05 0.03 0.03 18 7 0.01 - 0.13 0.02 0.01 0.03 19 7.5 0.01 - 0.19 0.03 0.02 0.02 a Below the LOQ Color analysis The color parameters of SS during stir-fry processing in this experiment are shown in Table 4 . It was apparent that the L * , a * and b * values decreased gradually, and the corresponding sample powder changed from brown to black. The color of CMMs is an important parameter to evaluate the processing degree. Modern analytical methods have validated that there is a close correlation between marker components and the color of CMMs [ 24 , 32 ]. However, there have been limited scientific data and theoretical bases to validate the relationships between color and the quality of CMMs. Considering that the color indicates that a CMM reaches a certain processing state, could color parameters be used as surrogates of changes in chemical constituents during processing? Table 4 The color measurement values of the Schizonepetae Spica samples subjected to the three processing temperatures over time ( n = 3) No. L * a * b * 1 40.45 2.73 5.61 2 35.14 2.49 1.49 3 34.62 2.51 1.12 4 34.08 2.33 0.60 5 34.41 2.36 0.75 6 34.30 2.39 0.62 7 34.40 2.40 0.62 8 33.33 1.96 -0.47 9 33.10 1.86 -0.82 10 33.09 1.90 -0.74 11 32.65 1.91 -0.80 12 32.62 1.77 -1.07 13 32.70 1.79 -1.16 14 33.06 1.80 -0.79 15 32.83 1.78 -1.14 16 33.09 1.68 -0.89 17 32.87 1.62 -1.29 18 32.54 1.66 -1.18 19 32.56 1.65 -1.24 Correlation analysis The correlations between the color parameters and chemical marker contents during the stir-fry processing of SS were investigated. The Pearson correlation coefficients and corresponding p -values in two sets of variables are listed in Table 5 . Significantly positive correlations were observed between the contents of four major ingredients (luteolin-7-O- β -D-glucoside, apigenin-7-O- β -D-glucoside, hesperidin and rosmarinic acid) and the L * , a * and b * values. The levels of another two main components (luteolin and apigenin) were found to be significantly and positively correlated with a * . However, the amounts of luteolin and apigenin had no significant correlation with L * and b * . Previous reports have shown that there is a certain correlation between the color parameters and chemical compositions in CMMs during the course of processing [ 33 – 36 ]. In this study, the three color parameters were associated significantly with the contents of luteolin-7-O- β -D-glucoside, apigenin-7-O- β -D-glucoside, hesperidin and rosmarinic acid, whereas a * was most significantly correlated with the luteolin and apigenin contents. Table 5 Pearson correlation analysis results between the color parameters and chemical marker contents during the stir-fry processing of Schizonepetae Spica Compound L * a * b * r P r P r P Luteolin-7-O- β -D-glucoside 0.985 ###a 0.000 0.854 ### 0.000 0.991 ### 0.000 Apigenin-7-O- β -D-glucoside 0.945 ### 0.000 0.917 ### 0.000 0.972 ### 0.000 Hesperidin 0.840 ### 0.000 0.922 ### 0.000 0.883 ### 0.000 Rosmarinic acid 0.836 ### 0.000 0.965 ### 0.000 0.887 ### 0.000 Luteolin 0.165 0.499 0.659 ##b 0.002 0.269 0.266 Apigenin 0.151 0.537 0.687 ## 0.001 0.268 0.268 a Correlation is significant at the 0.001 level b Correlation is significant at the 0.01 level Regression analysis To date, a series of quality control methods focusing on the essential oil of SS have been reported, including steam distillation, gas chromatography-mass spectrometry (GC-MS) and fingerprinting [ 37 , 38 ]. However, there are few reports regarding the determination of nonvolatile constituents from raw and processed SS. Additionally, laboratory instruments such as HPLC could provide accurate measurement results of marker compounds in SS during processing. However, these methods involve laborious, complex and time-consuming pretreatment of samples with extensive use of organic reagents that are unfriendly to the environment. Therefore, possible models of surrogate color parameters for marker constituents in SS during processing will be explored. According to the above results of correlation analysis, color analysis and the variation in the major constituents of SS during processing, statistically significant parameters ( L * , a * and b * ) were analyzed by the enter linear regression method to establish the regression model of luteolin-7-O- β -D-glucoside, apigenin-7-O- β -D-glucoside, hesperidin and rosmarinic acid. The optimal models were determined according to the maximum adjusted R 2 values (Table 6 ). The best individual regression models were established as follows: Luteolin-7-O- β -D-glucoside = -0.604 + 0.019· L * + 0.014· a * + 0.03· b * (1) Apigenin-7-O-β-D-glucoside = -0.361 + 0.009· L * + 0.066· a * + 0.018· b * (2) Hesperidin = -11.237 + 0.275· L * + 1.35· a * − 0.256· b * (3) Rosmarinic acid = -7.354 + 0.179· L * + 0.833· a * − 0.208· b * (4) For luteolin and apigenin, third-order polynomial curve fitting was performed for the data of each sample. The SPSS analysis process excluded a *2 as an unimportant factor, and the formulas and adjusted R 2 values (Table 6 ) were determined as follows: Luteolin = -2.977 + 2.217· a * − 0.146· a *3 (5) Apigenin = -1.562 + 1.154· a * − 0.074· a *3 (6) The ANOVA test results of coefficient values, standard errors and t -values for the color parameters included in each proposed model are presented in Table 7 . These results showed that the contents of 6 marker constituents could be represented well by polynomials of the color parameters, including L * , a * and b * . The models were statistically significant (p = 0.000), with adjusted R 2 values greater than 0.800, which indicated that good correlations were established between the color parameters and concentrations of different marker compounds. Thus, the contents of marker constituents of SS could be rapidly predicted by color parameters during processing, which represented the scientific elucidation of color as an important indicator for the identification of SS processing degree. However, a unified quantitative relationship between the color parameters and chemical marker contents for various SS samples could not be established because of the differences in a number of factors—such as plant cultivars, harvesting time, degradation degrees and many other poorly controlled aspects during stir-fry processing. Nevertheless, it is possible to develop specific prediction models for marker compounds in specific SS samples to monitor the degree of processing using color parameters. Further studies are warranted to establish the relationship between the alteration of color parameters and the changes in medicinal properties during processing. Table 6 Statistical evaluation for the prediction models Compound R R 2 Adjusted R 2 F P Luteolin-7-O- β -D-glucoside 0.991 0.983 0.980 289.785 0.000 Apigenin-7-O- β -D-glucoside 0.982 0.965 0.958 137.046 0.000 Hesperidin 0.938 0.880 0.856 36.758 0.000 Rosmarinic acid 0.974 0.948 0.938 91.242 0.000 Luteolin 0.971 0.942 0.935 129.771 0.000 Apigenin 0.910 0.828 0.807 38.570 0.000 Table 7 Regression analysis coefficients for the prediction models Compound Variable Coefficient value Standard error T -value Sig. Luteolin-7-O- β -D-glucoside Constant -0.604 -0.799 0.437 L * 0.019 0.397 0.935 0.365 a * 0.014 0.055 0.426 0.676 b * 0.030 0.550 1.060 0.306 Apigenin-7-O- β -D-glucoside Constant -0.361 -0.432 0.672 L * 0.009 0.227 0.371 0.716 a * 0.066 0.344 1.860 0.083 b * 0.018 0.447 0.598 0.559 Hesperidin Constant -11.237 -0.887 0.389 L * 0.275 0.895 0.793 0.440 a * 1.350 0.863 2.528 0.023 b * -0.256 -0.756 -0.548 0.592 Rosmarinic acid Constant -7.354 -1.831 0.087 L * 0.179 1.207 1.624 0.125 a * 0.833 1.107 4.921 0.000 b * -0.208 -1.273 -1.400 0.182 Luteolin Constant -2.977 -12.710 0.000 a * 2.217 6.700 13.034 0.000 a *3 -0.146 -6.083 -11.834 0.000 Apigenin Constant -1.562 -6.386 0.000 a * 1.154 5.747 6.500 0.000 a *3 -0.074 -5.096 -5.763 0.000 Conclusions Flavonoids and organic acids are the main nonvolatile constituents of SS, and they possess many pharmacological activities. The present study examined variations in the levels of six marker nonvolatile constituents and the color parameters of SS during stir-fry processing by using HPLC-DAD and colorimetry, respectively. The amounts of the four major ingredients (luteolin-7-O- β -D-glucoside, apigenin-7-O- β -D-glucoside, hesperidin and rosmarinic acid) and the three color parameters ( L * , a * and b * ) decreased with increasing temperature over time, whereas the contents of another two main components (luteolin and apigenin) initially increased before reaching a plateau and then decreased during processing. L * , a * and b * were recognized as the relevant parameters significantly associated with the luteolin-7-O- β -D-glucoside, apigenin-7-O- β -D-glucoside, hesperidin and rosmarinic acid contents in SS, while a * was most significantly related to the luteolin and apigenin contents in SS. By regression analysis, four optimal multiple linear regression models and two third-order polynomial models were established for the corresponding marker compounds as a function of relevant color parameters, with an adjusted R 2 value significantly greater than 0.800. For the first time, surrogate prediction using color parameters was developed for the simultaneous quantification of 6 marker substances including flavonoids and an organic acid during the processing of SS. Although these models could not be applied to various SS samples, the chemical marker contents could be rapidly predicted by the color parameters through the specific models. In short, colorimeter sensor technology and phytochemical analysis combined with chemometric methods provided scientific data and a theoretical basis to validate the relationships between color features and the processing degree of SS. The developed strategy offers new clues for the quality control standards of nonvolatile constituents of SS processing practices and provides useful references for other processing methods. Abbreviations CIE, International Commission on Illumination; CMM, Chinese medicinal material; DAD, diode array detector; SS, Schizonepetae Spica; SSC, Schizonepetae Spica Carbonisata; TCM, traditional Chinese medicine Declarations Acknowledgements Not applicable. Authors’ contributions HC and XL conceived and designed the experiments. XL performed the experiment and prepared the manuscript. HC, MW, YZ and ZM revised the manuscript. All authors have read and agreed to the published version of the manuscript. Funding This work was supported by the Research Project of Drug Standardization of National Pharmacopoeia Committee (2018Z006) and the 6 th National Academic Experience Inheritance Program of Famous Chinese Medicine Experts (Prof. Hui Cao) (No. 176-2017-XMZC-0166-01). Availability of data and materials The datasets used during this study are available from the corresponding author upon reasonable request. Ethics approval and consent to participate Not applicable. Consent for publication Not applicable. Competing interests The authors declare that they have no competing interests. Author details 1 Research Center for Traditional Chinese Medicine of Lingnan (Southern China), Jinan University, Guangzhou 510632, China. 2 National Engineering Research Center for Modernization of Traditional Chinese Medicine Lingnan Resources Branch, Guangzhou 510632, Guangdong, China. References Zhao ZZ, Liang ZT, Chan K, Lu GH, Lee ELM, Chen HB, et al. A unique issue in the standardization of Chinese materia medica: processing. Planta Med. 2010;76(17):1975-86. Fan YY, Wang CH, Jiang QD. The current situation and countermeasures of irrational use of toxic traditional Chinese medicine. Chin J Pharmacov. 2017;14(10):632-4. The State Commission of Chinese Pharmacopoeia. The Pharmacopoeia of the People's Republic of China 2020 edtion. Beijing: China Medical Science Press; 2020. Wu P, compiled by Sun XY, Sun FJ. Shen Nong Ben Cao Jing. Beijing: People's Medical Publishing House; 1984. Hu J, Shi RB, Zhang YH. Content determination of luteolin and hesperidin in the effective fractions of Spica Schizonepeta by HPLC. J Beijing Univ Tradit Chin Med. 2005;28(4):52-4. Du CZ, Qin JP, Chen YP, Cai Y. GC-MS analysis of volatile oil components in Schizonepeta tenuifolia Briq. from various habitats. Hubei Agric Sci. 2014;53(1):188-90. Jiang YH, Jiang DQ, Wu KJ, Peng LL. Contents determination of ursolic acid and oleanolic acid in different parts of Jiangxi Herba Schizonepetae and carbonized Herba Schizonepetae. China J Tradit Chin Med Pharm. 2016;31(3):1068-70. Shan MQ, Qian Y, Yu S, Guo SC, Zhang L, Ding AW, et al. Anti-inflammatory effect of volatile oil from Schizonepeta tenuifolia on carrageenin-induced pleurisy in rats and its application to study of appropriate harvesting time coupled with multi-attribute comprehensive index method. J Ethnopharmacol. 2016;194:580-6. Chen SG, Cheng ML, Chen KH, Horng JT, Liu CC, Wang SM, et al. Antiviral activities of Schizonepeta tenuifolia Briq. against enterovirus 71 in vitro and in vivo. Sci Rep. 2017;7(935):1-15. Ng YC, Kim YW, Lee JS, Lee SJ, Song MJ. Antiviral activity of Schizonepeta tenuifolia Briquet against noroviruses via induction of antiviral interferons. J Microbiol. 2018;56(9):683-9. Ding AW, Kong LD, Wu H, Wang SL, Long QJ, Yao Z, et al. Research on hemostatic constituents in carbonized Schizonepeta tenuifolia Briq. China J Chin Mater Med. 1993;18(9):535-8. Ding AW, Wu H, Kong LD, Wang SL, Gao ZZ, Zhao MX, et al. Research on hemostatic mechanism of extracts from carbonized Schizonepeta tenuifolia Briq. China J Chin Mater Med. 1993;18(10):598-600. Zhang Y. Application of Jingjiesui in treating gynecological diseases. Clin J Chin Med. 2016;8(31):69-70. He T, Tang Q, Zeng N, Gong XP. Study on effect and mechanism of volatile oil of Schizonepetae Herba and its essential components against influenza virus. China J Chin Mater Med. 2013;38(11):1772-7. Ma SC, Liu Y, Paul BPH, Yang Y, Vincent OEC, Spencer HSL, et al. RP-HPLC determination of hederagenin and oleanolic acid in Flos Lonicerae Japonicae. Chin J Pharm Anal. 2006;26(7):885-7. Ma SC, Liu Y, Paul BPH, Yang Y, Vincent OEC, Spencer HSL, et al. Antiviral activities of flavonoids isolated from Lonicera japonica Thunb. Chin J Pharm Anal. 2006;26(4):426-30. Shi Y, Shi RB, Liu B, Lu YR. Studies on antiviral flavonoids in Yinqiaosan powder. China J Chin Mater Med. 2001;26(5):320-3. Tang R, Chen K, Cosentino M, Lee KH. Apigenin-7-O- β -D-glucopyranoside, an anti-HIV principle from Kummerowia striata . Bioorg Med Chem Lett. 1994;4(3):455-8. Lin ZC, Fang YJ, Huang AY, Chen LY, Guo SH, Chen JW. Chemical constituents from Sedum aizoon and their hemostatic activity. Pharm Biol. 2014;52(11):1429-34. Su P, Wang GN, Wu D, Sheng XF. Progress in rosmarinic acid biological activities and its sources. Food Ferment Ind. 2008;34(12):135-8. Sung B, Chung HY, Kim ND. Role of apigenin in cancer prevention via the induction of apoptosis and autophagy. J cancer prev. 2016;21(4):216-26. Fung D, Lau CBS. Schizonepeta tenuifolia : chemistry, pharmacology, and clinical applications. J Clin Pharmacol. 2002;42(1):30-6. Administration of Health of Jiangsu province, China. The processing practice of Chinese crude drugs in Jiangsu province. Nanjing: Jiangsu Science and Technology Press; 2002. Sun M, Yan DH, Yang XL, Xue XY, Zhou SJ, Liang SW, et al. Quality assessment of crude and processed Arecae semen based on colorimeter and HPLC combined with chemometrics methods. J Sep Sci. 2017;40(10):2151-60. Lan ZW, Zhang Y, Sun Y, Ji D, Wang SM, Lu TL, et al. A mid-level data fusion approach for evaluating the internal and external changes determined by FT-NIR, electronic nose and colorimeter in Curcumae Rhizoma processing. J Pharm Biomed Anal. 2020;188:1-11. Fan JX, Wang S, Meng XS, Bao YR, Li TJ. Determination of six flavonoids in Schizonepeta tenuifolia from different areas by HPLC. Chin Tradit Herb Drugs. 2017;48(11):2292-5. Gu MJ, Ju JF, Zhu ZM. Optimization of extraction process for flavonoids from Schizonepatae Spica by central composite design-response surface methodology. Chin J Exp Tradit Med Form. 2015;21(8):29-33. Hu JH, Liu LL, Zhang YJ, Xiao W. Determination of cafferic acid and rosmarinic acid in Perilla frutescens leaves and Schizonepata tenuifolia by HPLC. Chin Tradit Herb Drugs. 2015;46(14):2155-9. Bolzon LB, dos Santos JS, Silva DB, Crevelin EJ, Moraes LAB, Lopes NP, et al. Apigenin-7-O-glucoside oxidation catalyzed by P450-bioinspired systems. J Inorg Biochem. 2017;170:117-24. Shen MY, Wang JL, Shi HP, Yan H, Chen PD, Yao WF, et al. Alternative processing technology for the preparation of carbonized Zingiberis Rhizoma by stir-frying with sand. Pharm Biol. 2020;58(1):131-7. Liu XD, Zhang Y, Wu MH, Ma ZG, Cao H. The potential transformation mechanisms of the marker components of Schizonepetae Spica and its charred product. Molecules. 2020;25(16):1-15. Liu XD, Yan DH, Deng XM, Zhao B, Xue XY, Wang SM, et al. Quality assessment of crude and processed Leonuri Fructus by chemical and color analysis combined with chemometric method. Chin Herb Med. 2018;10(4):388-95. Liu TR, Jin Y, Meng HB, Zhao YY, Zhou JH, Yuan Y, et al. Biological research of color and quality evaluation in "quality discrimination by character" of Chinese medicine. China J Chin Mater Med. 2020;45(19):4545-54. Yang L, Gong YT, Xu MS, Yang L, Chen JB, Dong L. Research on relationship between color and composition changes in processing of rhubarb charcoal based on "external and internal correlation". Chin Tradit Herb Drugs. 2020;51(22):5705-13. Zhang X, Li XQ, Wang Y, Li LY, Da YJ, Wang QH, et al. Dynamic correlation between constituents detected by HPLC and colors of samples in stir-frying process of Gardeniae Fructus Praeparatus. Chin Tradit Herb Drugs. 2018;49(17):4029-37. Li XQ, Wang Y, Zhang X, Li LY, Da YJ, Wang QH, et al. Correlation analysis of apparent color change and chemical composition content during processing of Gardeniae Fructus. Chin J Exp Tradit Med Form. 2018;24(13):1-5. Chun MH, Kim EK, Lee KR, Jung JH, Hong J. Quality control of Schizonepeta tenuifolia Briq by solid-phase microextraction gas chromatography/mass spectrometry and principal component analysis. Microchem J. 2010;95(1):25-31. Liu X, Zhang Y, Wu M, Ma Z, Cao H. Color discrimination and gas chromatography-mass spectrometry fingerprint based on chemometrics analysis for the quality evaluation of Schizonepetae Spica. Plos One. 2020;15(1):1-15. Cite Share Download PDF Status: Published Journal Publication published 13 Jan, 2022 Read the published version in Food Analytical Methods → Version 1 posted You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-414931","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research","associatedPublications":[],"authors":[{"id":21112436,"identity":"73a2d30a-b40a-4ef3-ad1d-92c18c67647d","order_by":0,"name":"Xindan Liu","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAAyElEQVRIiWNgGAWjYBACfvb+jw8+/LBh5mdvIFKLZM8BY8OZPWnsQAaRWgxmJJhJ87Ad5gcyiNXCkJAmOYOHWdpA8vHGGww1NtEEtZgzHDhs8cGCzdhcOq3YguFYWm4DIS2WjY2NN2fw8CRbzs4xk2BsOExYi8FhZgagXyTqN9w8Q6yWY2xMQC0GzAY3eIjUItnDwwwM5ARmyR6gXxKI8Qu//BtGYFT+B0bl4Y03PtTYENaC4kiJBFKUQ7SQqmMUjIJRMApGBgAAdrk+L39XKacAAAAASUVORK5CYII=","orcid":"https://orcid.org/0000-0003-0259-0502","institution":"Jinan University","correspondingAuthor":true,"submittingAuthor":false,"prefix":"","firstName":"Xindan","middleName":"","lastName":"Liu","suffix":""},{"id":21112437,"identity":"8b576769-1fb4-4b9c-9b6b-35397985080c","order_by":1,"name":"Ying Zhang","email":"","orcid":"","institution":"Jinan University","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Ying","middleName":"","lastName":"Zhang","suffix":""},{"id":21112438,"identity":"b2b39f2f-8679-41d8-be94-f01c345c9824","order_by":2,"name":"Menghua Wu","email":"","orcid":"","institution":"Jinan University","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Menghua","middleName":"","lastName":"Wu","suffix":""},{"id":21112439,"identity":"640fad13-f3a5-49d2-8e2f-750cf1ee42f7","order_by":3,"name":"Zhiguo Ma","email":"","orcid":"","institution":"Jinan University","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Zhiguo","middleName":"","lastName":"Ma","suffix":""},{"id":21112440,"identity":"8be725d3-fba6-41dd-99bc-39dadad52f78","order_by":4,"name":"Hui Cao","email":"","orcid":"","institution":"Jinan University","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Hui","middleName":"","lastName":"Cao","suffix":""}],"badges":[],"createdAt":"2021-04-12 15:03:51","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-414931/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-414931/v1","draftVersion":[],"editorialEvents":[{"content":"https://doi.org/10.1007/s12161-021-02156-4","type":"published","date":"2022-01-13T17:48:46+00:00"}],"editorialNote":"","failedWorkflow":false,"files":[{"id":8025023,"identity":"7a6f6a5d-d78b-4029-ba2e-9d2949ea79fe","added_by":"auto","created_at":"2021-04-14 23:06:18","extension":"jpg","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":43202,"visible":true,"origin":"","legend":"Representative chromatograms of reference substances (A) and samples (B-E). B, Raw Schizonepetae Spica; C-E, Representative chromatograms of Schizonepetae Spica during stir-fry processing under different treatment conditions (C, 240°C ± 10°C, 5 min; D, 300°C ± 10°C, 5 min; E, 360°C ± 10°C, 5 min); 1, luteolin-7-O-β-D-glucoside; 2, apigenin-7-O-β-D-glucoside; 3, hesperidin; 4, rosmarinic acid; 5, luteolin; 6, apigenin","description":"","filename":"1.jpg","url":"https://assets-eu.researchsquare.com/files/rs-414931/v1/be75d67b4bf438ac95c06d48.jpg"},{"id":8025155,"identity":"23ff58c3-b64f-4312-8e28-820291b276b6","added_by":"auto","created_at":"2021-04-14 23:09:18","extension":"jpg","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":53318,"visible":true,"origin":"","legend":"Changes in the amounts of luteolin-7-O-β-D-glucoside, apigenin-7-O-β-D-glucoside, hesperidin, rosmarinic acid, luteolin and apigenin in the Schizonepetae Spica samples subjected to the three processing temperatures over time (n = 2)","description":"","filename":"2.jpg","url":"https://assets-eu.researchsquare.com/files/rs-414931/v1/3179f1d78d2e17de74bca27f.jpg"},{"id":17295218,"identity":"0022b0d4-d713-49d6-916c-d17f32aa7ac7","added_by":"auto","created_at":"2022-01-13 17:48:49","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":536218,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-414931/v1/fef03e95-29f5-4e4b-be36-54251e7c58d2.pdf"}],"financialInterests":"","formattedTitle":"Colorimetric parameters correlated with the variation in the marker constituent contents during the stir-fry processing of Schizonepetae Spica","fulltext":[{"header":"Background","content":"\u003cp\u003eChinese medicinal materials (CMMs) often have to be processed by using physical or chemical treatment before prescription or clinical usage. The aims of processing are to alter the clinical efficacy and/or reduce the toxicity of CMMs to fulfill the different requirements of therapy [\u003cspan class=\"CitationRef\"\u003e1\u003c/span\u003e]. There is a close relationship between the efficacy, safety and processing of CMMs. Improper processing methods may produce poor clinical effects or even result in poisoning [\u003cspan class=\"CitationRef\"\u003e2\u003c/span\u003e]. Characteristics of CMMs such as color are usually used to assess the degree of processing. For example, when dry Zingiberis Rhizoma is roasted with sand until it becomes brown externally, it is called Zingiberis Rhizoma Praeparatum. Cirsii Japonici Herba is called Cirsii Japonici Herba Carbonisata when it is stir-fried until the surface becomes black. However, this approach often depends to a certain extent on the practitioner\u0026rsquo;s experience, which is strongly subjective and lacks objective criteria, so modern scientific analytical techniques are needed to confirm the validity of associations between the color and processing degree of CMMs.\u003c/p\u003e\n\u003cp\u003eSchizonepetae Spica (SS) is the dried spike of \u003cem\u003eSchizonepeta tenuifolia\u003c/em\u003e Briq. (Chinese Pharmacopoeia, 2020 edition) [\u003cspan class=\"CitationRef\"\u003e3\u003c/span\u003e]. It was first recorded in \u003cem\u003eShen Nong Ben Cao Jing\u003c/em\u003e (Shen Nong\u0026rsquo;s herbal classic), a book written 2000 years ago [\u003cspan class=\"CitationRef\"\u003e4\u003c/span\u003e]. Chemical studies revealed that SS contains volatile oils, flavonoids, organic acids and so on [\u003cspan class=\"CitationRef\"\u003e5\u003c/span\u003e\u0026ndash;\u003cspan class=\"CitationRef\"\u003e7\u003c/span\u003e]. Pharmacological analyses have shown that SS has three main biological properties, namely, anti-inflammatory [\u003cspan class=\"CitationRef\"\u003e8\u003c/span\u003e], antiviral [\u003cspan class=\"CitationRef\"\u003e9\u003c/span\u003e, \u003cspan class=\"CitationRef\"\u003e10\u003c/span\u003e], and hemostatic activity [\u003cspan class=\"CitationRef\"\u003e11\u003c/span\u003e\u0026ndash;\u003cspan class=\"CitationRef\"\u003e13\u003c/span\u003e]. The essential oils of SS are recognized as the major constituents responsible for its anti-inflammatory and antiviral effects [\u003cspan class=\"CitationRef\"\u003e8\u003c/span\u003e, \u003cspan class=\"CitationRef\"\u003e14\u003c/span\u003e]. In addition, the nonvolatile compounds such as flavonoids and organic acids from SS exhibit various biological activities. For example, luteolin-7-O-\u003cem\u003e\u0026beta;\u003c/em\u003e-D-glucoside has been demonstrated to have good biological activity in terms of anti-inflammatory and antiviral effects [\u003cspan class=\"CitationRef\"\u003e15\u003c/span\u003e, \u003cspan class=\"CitationRef\"\u003e16\u003c/span\u003e]. Apigenin-7-O-\u003cem\u003e\u0026beta;\u003c/em\u003e-D-glucoside, hesperidin and luteolin have also been documented to possess significant antiviral activity [\u003cspan class=\"CitationRef\"\u003e5\u003c/span\u003e, \u003cspan class=\"CitationRef\"\u003e17\u003c/span\u003e, \u003cspan class=\"CitationRef\"\u003e18\u003c/span\u003e]. Moreover, luteolin has been shown to be a potent hemostatic drug candidate [\u003cspan class=\"CitationRef\"\u003e19\u003c/span\u003e]. Rosmarinic acid exhibits many biological properties, including antioxidant, antibacterial, anti-inflammatory and antiallergic effects [\u003cspan class=\"CitationRef\"\u003e20\u003c/span\u003e]. Apigenin has notable anticancer activity in vitro and in vivo [\u003cspan class=\"CitationRef\"\u003e21\u003c/span\u003e]. Thus, the contents of flavonoids and organic acids could be used as evaluation markers for SS. The herb is commonly used in traditional Chinese medicine (TCM) prescriptions to treat the common cold, fever, bloody stool and metrorrhagia [\u003cspan class=\"CitationRef\"\u003e22\u003c/span\u003e]. To treat the common cold and fever, TCM practitioners often prescribe raw SS, while to treat bloody stool and metrorrhagia, they usually use Schizonepetae Spica Carbonisata (SSC; raw SS processed by stir-frying until the surface becomes blackish-brown and the interior turns dark yellow) [\u003cspan class=\"CitationRef\"\u003e3\u003c/span\u003e]. However, the quality control standards of processing practices are inconsistent in terms of the national standard and various local standards. For example, the processing method \u0026ldquo;stir-frying until the surface becomes blackish-brown and the interior turns dark yellow\u0026rdquo; is recorded in the Chinese Pharmacopoeia (2020 edition), while stir-frying until the surface becomes dark brown and the interior turns brown is recorded in \u0026ldquo;The Practices of Processing Chinese Crude Drugs in Jiangsu Province\u0026rdquo; [\u003cspan class=\"CitationRef\"\u003e23\u003c/span\u003e]. In addition, color discrimination of SSC is mainly based on the experience of individual operators. To guarantee the quality of SSC, a standardized processing method is critical. Therefore, the above problems of \u0026ldquo;SS with several processing methods and differences in different areas\u0026rdquo; should be harmonized, and consistent practices based on modern scientific studies need to be established.\u003c/p\u003e\n\u003cp\u003eIn recent years, advances in sensor technologies such as colorimeters, electronic noses and electronic tongues have provided signals related to sensory attributes, making it easier to objectively characterize the color, aroma and taste of various products. Some studies have reported the use of a colorimeter to substitute the traditional color discrimination of CMMs [\u003cspan class=\"CitationRef\"\u003e24\u003c/span\u003e, \u003cspan class=\"CitationRef\"\u003e25\u003c/span\u003e]. The colorimeter technique can be used to measure processed CMM products, with the additional advantage of controlling the technological parameters. Both colorimetry techniques and modern analytical techniques should be combined to map marker components in order to evaluate the scientific elucidation of color discrimination behind processing procedures and the quality of processing.\u003c/p\u003e\n\u003cp\u003eTherefore, the main purposes of this study were to investigate the relationship between chromatic aberrations and content variations in the marker nonvolatile substances of SS during processing in order to clarify the core scientific elucidation of color as an important indicator of the degree of processing. For this purpose, first, HPLC coupled with a diode array detector (DAD) was used to evaluate five flavonoids and one organic acid of SS during stir-fry processing, and the powder color was simultaneously determined using a colorimeter. Second, the correlations between marker constituents and chromatism were investigated by Pearson correlation analysis. Finally, polynomial regression models were established with the color parameters to rapidly predict the contents of the marker constituents. This was the first study to develop a method for the quantitative analysis of nonvolatile ingredients of SS using color parameters during stir-fry processing.\u003c/p\u003e"},{"header":"Materials And Methods","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e\n\u003cp\u003e\u003cstrong\u003eMaterials and reagents\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eRaw SS, originating from Henan Province (China), was provided by Hexiang Pharmaceutical Co. Ltd., and authenticated in accordance with the SS monograph in the Chinese Pharmacopoeia (2020 edition) by Dr. Ying Zhang, Jinan University, P. R. China. The voucher specimen (No. HX18C01) was deposited at the Research Center for Traditional Chinese Medicine of Lingnan (Southern China), Jinan University.\u003c/p\u003e\n\u003cp\u003eAcetonitrile (HPLC grade), methanol (HPLC grade) and formic acid (HPLC grade) were purchased from Fisher Scientific (Fair Lawn, NJ, USA). The chemical standards luteolin-7-O-\u003cem\u003e\u0026beta;\u003c/em\u003e-D-glucoside (No. M-025-190115), hesperidin (No. C-006-180216), rosmarinic acid (No. 190921), luteolin (No. M-007-181216) and apigenin (No. Q-002-180131) were supplied by Chengdu Ruifensi Biotechnology (Sichuan, China). Apigenin-7-O-\u003cem\u003e\u0026beta;\u003c/em\u003e-D-glucoside (No. T4S0295) was acquired from Tianjun Biotechnology (Guangzhou, China). The purity of the compounds was greater than 95%, as detected by HPLC-DAD. Deionized water was purified by passing distilled water through a Milli-Q purification system (Millipore, Bedford, MA, USA). All other chemical reagents were of analytical grade.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eSample preparation\u003c/strong\u003e\u003c/p\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec4\" class=\"Section2\"\u003e\n\u003cp\u003eTen grams of dried SS slices (10\u0026ndash;15 mm in length) were placed in a pan and stir-fried at different temperatures (240\u0026deg;C\u0026thinsp;\u0026plusmn;\u0026thinsp;10\u0026deg;C, 300\u0026deg;C\u0026thinsp;\u0026plusmn;\u0026thinsp;10\u0026deg;C, and 360\u0026deg;C\u0026thinsp;\u0026plusmn;\u0026thinsp;10\u0026deg;C) for 5, 5.5, 6, 6.5, 7 and 7.5 min. Thus, we prepared 18 batches of SSC samples, and then, we determined the contents of the marker constituents and the color parameters in each batch of the prepared SSC samples as well as the raw SS.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eQuantitative analysis of the main chemical ingredient content of SS and SSC samples\u003c/strong\u003e\u003c/p\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec5\" class=\"Section2\"\u003e\n\u003cp\u003eThe SS and SSC samples were ground and filtered through a 24-mesh sieve. The powder (2 g) was weighed accurately and macerated in 20 mL of 75% ethanol. Then, the sample was extracted for 60 min by hot reflux extraction in a water bath. A 10 \u0026micro;L supernatant of the extracts was injected for HPLC analysis after filtration with a 0.45-\u0026micro;m membrane.\u003c/p\u003e\n\u003cp\u003eAn UltiMate 3000 liquid chromatography system (Thermo Scientific, Bremen, Germany) equipped with a diode array detector and an ACE Excel 5 C18 column (4.6 mm \u0026times;250 mm, 5 \u0026micro;m; ACE, Scotland, UK) was used throughout this study. The mobile phase consisted of A (0.1% formic acid aqueous solution) and B (acetonitrile) using a gradient elution of 8%-20% B from 0\u0026ndash;20 min, 20% B holding from 20\u0026ndash;30 min, 20%-30% B from 30\u0026ndash;50 min, and 30%-8% B from 50\u0026ndash;60 min. The column temperature, flow rate, detection wavelength and injection volume were 30\u0026deg;C, 1 mL/min, 283 nm and 10 \u0026micro;L, respectively.\u003c/p\u003e\n\u003cp\u003eThe stock solution of the mixture of the 6 marker components was prepared by dissolving the standards in methanol in a 25 mL volumetric flask. A series of appropriate concentrations were analyzed in triplicate to establish the calibration curve. The LODs and LOQs were determined as 3 and 10 times the signal-to-noise (S/N) ratios, respectively. The interday and intraday precisions were determined by analyzing the stock standard solution containing the 6 components, with six repetitions daily over three consecutive days. Six different working solutions prepared from the same sample were analyzed to confirm the repeatability. The same sample was tested at 0, 2, 4, 8, 12, 16, 20, and 24 h to confirm the stability. The recovery was determined by adding three concentration levels (80%, 100% and 120%) of the mixed standard solutions to known amounts of sample. Then, the fortified samples were extracted and analyzed by the proposed method. The mean recoveries were estimated using the following formula: recovery (%) = (amount found \u0026ndash; original amount) / amount spiked \u0026times; 100%.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eColor measurement\u003c/strong\u003e\u003c/p\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec6\" class=\"Section2\"\u003e\n\u003cp\u003eThe SS and SSC samples were ground and filtered through an 80-mesh sieve to ensure the uniformity of the particles. The color measurement was performed by a CR-410 colorimeter (Konica Minolta, Japan). A Fluke-63 portable infrared thermometer (Fluke, USA) was used to determine the temperature. The SS and SSC samples were filled into a powder box and observed under a D65 light source. The measuring diameter was set at 50 mm with a standard viewing angle of 2 degrees. The International Commission on Illumination (CIE) system was adopted for color quantization, with the chroma space represented by \u003cem\u003eL\u003c/em\u003e\u003csup\u003e*\u003c/sup\u003e, \u003cem\u003ea\u003c/em\u003e\u003csup\u003e*\u003c/sup\u003e and \u003cem\u003eb\u003c/em\u003e\u003csup\u003e*\u003c/sup\u003e. \u003cem\u003eL\u003c/em\u003e\u003csup\u003e*\u003c/sup\u003e represents the brightness from black to white, \u003cem\u003ea\u003c/em\u003e\u003csup\u003e*\u003c/sup\u003e represents the red-green axis, and \u003cem\u003eb\u003c/em\u003e\u003csup\u003e*\u003c/sup\u003e represents the yellow-blue axis.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eStatistical analysis\u003c/strong\u003e\u003c/p\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec7\" class=\"Section2\"\u003e\n\u003cp\u003eThe correlation between the contents of 6 main marker constituents and the color parameters was analyzed by Pearson correlation analysis. Multiple linear regression models and third-order polynomial functions for the marker components and the color parameters were established by using the enter linear regression method and curve fitting with a polynomial model. The data analysis of variables using Pearson correlation analysis, multiple linear regression analysis (enter) and third-order polynomial curve fitting were performed using SPSS 20.0 software (IBM Inc., USA).\u003c/p\u003e\n\u003c/div\u003e"},{"header":"Results And Discussion","content":"\u003cdiv id=\"Sec9\" class=\"Section2\"\u003e\n\u003cp\u003e\u003cstrong\u003eHPLC method validation\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eValidation of the HPLC method was conducted by following the recommendation in the literature [\u003cspan class=\"CitationRef\"\u003e26\u003c/span\u003e, \u003cspan class=\"CitationRef\"\u003e27\u003c/span\u003e]. The 6 marker compounds of SS and SSC were identified using reference standards of luteolin-7-O-\u003cem\u003e\u0026beta;\u003c/em\u003e-D-glucoside, apigenin-7-O-\u003cem\u003e\u0026beta;\u003c/em\u003e-D-glucoside, hesperidin, rosmarinic acid, luteolin and apigenin, as well as comparisons with the literature [\u003cspan class=\"CitationRef\"\u003e26\u003c/span\u003e, \u003cspan class=\"CitationRef\"\u003e28\u003c/span\u003e, \u003cspan class=\"CitationRef\"\u003e29\u003c/span\u003e]. The proposed HPLC method was validated by determining the linearity, LOD, LOQ, inter- and intraday precisions, repeatability, stability, and recoveries. The equations, linear ranges, LODs and LOQs for the 6 marker compounds are summarized in Table\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e1\u003c/span\u003e. The intra- and interday RSDs were 0.03%-0.50% and 0.22%-0.73%, respectively (Table\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e2\u003c/span\u003e). To confirm the repeatability, six parallel ethanol extracts of SS were analyzed. The RSDs of the 6 marker components detected were 0.56%-2.34%. The RSD values of the HPLC stability test were found to be less than 3.0% (Table\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e2\u003c/span\u003e). The measured recoveries of 6 marker compounds ranged from 95.47\u0026ndash;104.54%, with an RSD between 0.13% and 2.91%. All these results demonstrated that the developed HPLC method was suitable for the analysis of the constituents in SS and SSC samples.\u003c/p\u003e\n\u003cdiv class=\"gridtable\"\u003e\n\u003ctable id=\"Tab1\" border=\"1\"\u003e\u003ccaption\u003e\n\u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e\n\u003cdiv class=\"CaptionContent\"\u003e\n\u003cp\u003eCalibration data for the 6 marker compounds by HPLC\u003c/p\u003e\n\u003c/div\u003e\n\u003c/caption\u003e\n\u003cthead\u003e\n\u003ctr\u003e\n\u003cth align=\"left\"\u003e\n\u003cp\u003eCompound\u003c/p\u003e\n\u003c/th\u003e\n\u003cth align=\"left\"\u003e\n\u003cp\u003eRegression equation\u003c/p\u003e\n\u003c/th\u003e\n\u003cth align=\"left\"\u003e\n\u003cp\u003e\u003cem\u003eR\u003c/em\u003e\u003csup\u003e2\u003c/sup\u003e\u003c/p\u003e\n\u003c/th\u003e\n\u003cth align=\"left\"\u003e\n\u003cp\u003eLinear range (\u0026micro;g/mL)\u003c/p\u003e\n\u003c/th\u003e\n\u003cth align=\"left\"\u003e\n\u003cp\u003eLOD\u003csup\u003ea\u003c/sup\u003e (\u0026micro;g/mL)\u003c/p\u003e\n\u003c/th\u003e\n\u003cth align=\"left\"\u003e\n\u003cp\u003eLOQ\u003csup\u003eb\u003c/sup\u003e (\u0026micro;g/mL)\u003c/p\u003e\n\u003c/th\u003e\n\u003c/tr\u003e\n\u003c/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eLuteolin-7-O-\u003cem\u003e\u0026beta;\u003c/em\u003e-D-glucoside\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e\u003cem\u003ey\u003c/em\u003e\u003csup\u003ec\u003c/sup\u003e = 0.1497\u003cem\u003ex\u003c/em\u003e\u003csup\u003ed\u003c/sup\u003e\u0026thinsp;+\u0026thinsp;0.2286\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.9992\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e0.80-159.20\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.29\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.97\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eApigenin-7-O-\u003cem\u003e\u0026beta;\u003c/em\u003e-D-glucoside\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e\u003cem\u003ey\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.2128\u003cem\u003ex\u003c/em\u003e\u0026thinsp;+\u0026thinsp;0.0483\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.9999\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e0.48-48.00\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.37\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e1.24\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eHesperidin\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e\u003cem\u003ey\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.1912\u003cem\u003ex\u003c/em\u003e \u0026ndash; 0.4667\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.9999\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e3.08\u0026ndash;616.00\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.30\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.98\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eRosmarinic acid\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e\u003cem\u003ey\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.2063\u003cem\u003ex\u003c/em\u003e \u0026minus;\u0026thinsp;0.2390\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.9999\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e1.62\u0026ndash;324.00\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.26\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.87\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eLuteolin\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e\u003cem\u003ey\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.1966\u003cem\u003ex\u003c/em\u003e\u0026thinsp;+\u0026thinsp;0.1069\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.9998\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e0.47\u0026ndash;141.60\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.10\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.34\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eApigenin\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e\u003cem\u003ey\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.3038\u003cem\u003ex\u003c/em\u003e \u0026minus;\u0026thinsp;0.0788\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.9999\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e0.40\u0026ndash;120.00\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.08\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.27\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003c/tbody\u003e\n\u003ctfoot\u003e\n\u003ctr\u003e\n\u003ctd colspan=\"6\"\u003e\u003csup\u003ea\u003c/sup\u003e Limit of detection\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd colspan=\"6\"\u003e\u003csup\u003eb\u003c/sup\u003e Limit of quantification\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd colspan=\"6\"\u003e\u003csup\u003ec\u003c/sup\u003e Peak area\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd colspan=\"6\"\u003e\u003csup\u003ed\u003c/sup\u003e Amount of injected compound (\u0026micro;g/mL)\u003c/td\u003e\n\u003c/tr\u003e\n\u003c/tfoot\u003e\n\u003c/table\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e\n\u003c/div\u003e\n\u003cdiv class=\"gridtable\"\u003e\n\u003ctable id=\"Tab2\" border=\"1\"\u003e\u003ccaption\u003e\n\u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e\n\u003cdiv class=\"CaptionContent\"\u003e\n\u003cp\u003ePrecision, repeatability, stability and recovery data for the 6 marker compounds by HPLC\u003c/p\u003e\n\u003c/div\u003e\n\u003c/caption\u003e\n\u003cthead\u003e\n\u003ctr\u003e\n\u003cth rowspan=\"2\" align=\"left\"\u003e\n\u003cp\u003eCompound\u003c/p\u003e\n\u003c/th\u003e\n\u003cth colspan=\"2\" align=\"left\"\u003e\n\u003cp\u003ePrecision (RSD, %)\u003c/p\u003e\n\u003c/th\u003e\n\u003cth rowspan=\"2\" align=\"left\"\u003e\n\u003cp\u003eRepeatability (RSD, %,\u003c/p\u003e\n\u003cp\u003e\u003cem\u003en\u003c/em\u003e\u0026thinsp;=\u0026thinsp;6)\u003c/p\u003e\n\u003c/th\u003e\n\u003cth rowspan=\"2\" align=\"left\"\u003e\n\u003cp\u003eStability (RSD, %, \u003cem\u003en\u003c/em\u003e\u0026thinsp;=\u0026thinsp;6)\u003c/p\u003e\n\u003c/th\u003e\n\u003cth colspan=\"2\" align=\"left\"\u003e\n\u003cp\u003eRecovery\u003c/p\u003e\n\u003cp\u003e(\u003cem\u003en\u003c/em\u003e\u0026thinsp;=\u0026thinsp;3)\u003c/p\u003e\n\u003c/th\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003cth align=\"left\"\u003e\n\u003cp\u003eIntraday (\u003cem\u003en\u003c/em\u003e\u0026thinsp;=\u0026thinsp;6)\u003c/p\u003e\n\u003c/th\u003e\n\u003cth align=\"left\"\u003e\n\u003cp\u003eInterday (\u003cem\u003en\u003c/em\u003e\u0026thinsp;=\u0026thinsp;3)\u003c/p\u003e\n\u003c/th\u003e\n\u003cth align=\"left\"\u003e\n\u003cp\u003eMean (%)\u003c/p\u003e\n\u003c/th\u003e\n\u003cth align=\"left\"\u003e\n\u003cp\u003eRSD (%)\u003c/p\u003e\n\u003c/th\u003e\n\u003c/tr\u003e\n\u003c/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eLuteolin-7-O-\u003cem\u003e\u0026beta;\u003c/em\u003e-D-glucoside\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.03\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.28\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e1.77\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e2.76\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e98.52\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.72\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e101.94\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e1.07\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e100.24\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e1.80\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eApigenin-7-O-\u003cem\u003e\u0026beta;\u003c/em\u003e-D-glucoside\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.06\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.24\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e1.46\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e2.59\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e95.47\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.35\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e97.35\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.50\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e96.18\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e1.52\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eHesperidin\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.09\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.44\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.56\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.28\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e104.54\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.36\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e104.72\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e1.06\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e101.17\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e1.81\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eRosmarinic acid\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.04\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.22\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.93\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e1.29\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e102.92\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.13\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e103.54\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.87\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e100.54\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e1.71\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eLuteolin\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.09\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.65\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.57\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e2.79\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e100.97\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.90\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e102.40\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.31\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e99.35\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e2.91\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eApigenin\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.50\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.73\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e2.34\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.79\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e99.18\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e1.25\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e102.07\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e2.57\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e99.47\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e1.55\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e\n\u003c/div\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec10\" class=\"Section2\"\u003e\n\u003cp\u003e\u003cstrong\u003eChanges in marker compounds during the stir-fry processing of Schizonepetae Spica under different treatment conditions\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe developed method was applied to simultaneously determine the amount of 6 marker compounds during the stir-fry processing of SS at different temperatures over time. Representative HPLC chromatograms of the standard analytes and the samples are shown in Fig.\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e1\u003c/span\u003e. Comparison of the chromatograms of samples at various stir-fry temperatures revealed that the contents of four major ingredients (luteolin-7-O-\u003cem\u003e\u0026beta;\u003c/em\u003e-D-glucoside, apigenin-7-O-\u003cem\u003e\u0026beta;\u003c/em\u003e-D-glucoside, hesperidin and rosmarinic acid) decreased with increasing temperature, whereas the levels of another two main components (luteolin and apigenin) first increased and then progressively decreased with increasing processing temperature. The quantitative results showed remarkable variation among different samples in the contents of the 6 marker compounds (Table\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e3\u003c/span\u003e and Fig.\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e2\u003c/span\u003e). The amounts of luteolin-7-O-\u003cem\u003e\u0026beta;\u003c/em\u003e-D-glucoside, apigenin-7-O-\u003cem\u003e\u0026beta;\u003c/em\u003e-D-glucoside, hesperidin and rosmarinic acid in the samples derived from the three different processing temperatures decreased with increasing processing time. In contrast, the amounts of luteolin and apigenin initially increased until they reached a plateau and decreased with time in all three cases. In the current study, the contents of these 6 marker compounds fluctuated slightly among different time points, which might be attributed to inhomogeneous stir-fry processing [\u003cspan class=\"CitationRef\"\u003e24\u003c/span\u003e, \u003cspan class=\"CitationRef\"\u003e30\u003c/span\u003e]. Our recent study showed that the increased levels of luteolin and apigenin might result from the degradation of the glucosidic bond of luteolin-7-O-\u003cem\u003e\u0026beta;\u003c/em\u003e-D-glucoside and apigenin-7-O-\u003cem\u003e\u0026beta;\u003c/em\u003e-D-glucoside under high-temperature during stir-fry processing [\u003cspan class=\"CitationRef\"\u003e31\u003c/span\u003e]. In general, the amounts of the 6 major constituents decreased gradually with the processing temperature over time. The occurrence of splitting decomposition or cracking of the chemical structures during the heating process may account for these declining phenomena.\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e\n\u003cdiv class=\"gridtable\"\u003e\n\u003ctable id=\"Tab3\" border=\"1\"\u003e\u003ccaption\u003e\n\u003cdiv class=\"CaptionNumber\"\u003eTable 3\u003c/div\u003e\n\u003cdiv class=\"CaptionContent\"\u003e\n\u003cp\u003eContents of 6 marker constituents of Schizonepetae Spica samples during stir-fry processing at different temperatures over time\u003c/p\u003e\n\u003c/div\u003e\n\u003c/caption\u003e\n\u003cthead\u003e\n\u003ctr\u003e\n\u003cth rowspan=\"2\" align=\"left\"\u003e\n\u003cp\u003eNo.\u003c/p\u003e\n\u003c/th\u003e\n\u003cth rowspan=\"2\" align=\"left\"\u003e\n\u003cp\u003eHeating temperature (\u0026deg;C)\u003c/p\u003e\n\u003c/th\u003e\n\u003cth rowspan=\"2\" align=\"left\"\u003e\n\u003cp\u003eHeating time (min)\u003c/p\u003e\n\u003c/th\u003e\n\u003cth colspan=\"6\" align=\"left\"\u003e\n\u003cp\u003eContents of flavonoids and phenolic acid (mg/g, \u003cem\u003en\u003c/em\u003e\u0026thinsp;=\u0026thinsp;2)\u003c/p\u003e\n\u003c/th\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003cth align=\"left\"\u003e\n\u003cp\u003eLuteolin-7-O-\u003cem\u003e\u0026beta;\u003c/em\u003e-D-glucoside\u003c/p\u003e\n\u003c/th\u003e\n\u003cth align=\"left\"\u003e\n\u003cp\u003eApigenin-7-O-\u003cem\u003e\u0026beta;\u003c/em\u003e-D-glucoside\u003c/p\u003e\n\u003c/th\u003e\n\u003cth align=\"left\"\u003e\n\u003cp\u003eHesperidin\u003c/p\u003e\n\u003c/th\u003e\n\u003cth align=\"left\"\u003e\n\u003cp\u003eRosmarinic acid\u003c/p\u003e\n\u003c/th\u003e\n\u003cth align=\"left\"\u003e\n\u003cp\u003eLuteolin\u003c/p\u003e\n\u003c/th\u003e\n\u003cth align=\"left\"\u003e\n\u003cp\u003eApigenin\u003c/p\u003e\n\u003c/th\u003e\n\u003c/tr\u003e\n\u003c/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e1\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e0\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e0\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.38\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e0.26\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e2.06\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.97\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.10\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.02\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e2\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd rowspan=\"6\" align=\"left\"\u003e\n\u003cp\u003e240\u0026thinsp;\u0026plusmn;\u0026thinsp;10\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e5\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.16\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e0.14\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e1.67\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.71\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.25\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.21\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e3\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e5.5\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.14\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e0.12\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e1.37\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.62\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.30\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.20\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e4\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e6\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.12\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e0.11\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e1.27\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.60\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.34\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.20\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e5\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e6.5\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.12\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e0.10\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e1.28\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.65\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.35\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.21\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e6\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e7\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.10\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e0.09\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e1.11\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.60\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.36\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.19\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e7\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e7.5\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.10\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e0.09\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e1.21\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.63\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.35\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.20\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e8\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd rowspan=\"6\" align=\"left\"\u003e\n\u003cp\u003e300\u0026thinsp;\u0026plusmn;\u0026thinsp;10\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e5\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.05\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e0.03\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.66\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.39\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.28\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.12\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e9\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e5.5\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.03\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e0.01\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.41\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.25\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.25\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.08\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e10\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e6\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.03\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e0.01\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.51\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.29\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.23\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.10\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e11\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e6.5\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.03\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e0.01\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.39\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.24\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.20\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.08\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e12\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e7\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.01\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e-\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.20\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.12\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.15\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.05\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e13\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e7.5\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.02\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e-\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.32\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.18\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.17\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.07\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e14\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd rowspan=\"6\" align=\"left\"\u003e\n\u003cp\u003e360\u0026thinsp;\u0026plusmn;\u0026thinsp;10\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e5\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.05\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e0.04\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.81\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.31\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.12\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.07\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e15\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e5.5\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.06\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e0.04\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.87\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.32\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.11\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.06\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e16\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e6\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.04\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e0.03\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.71\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.26\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.09\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.06\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e17\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e6.5\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.01\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e-\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.21\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.05\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.03\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.03\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e18\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e7\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.01\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e-\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.13\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.02\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.01\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.03\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e19\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e7.5\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.01\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e-\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.19\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.03\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.02\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.02\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003c/tbody\u003e\n\u003ctfoot\u003e\n\u003ctr\u003e\n\u003ctd colspan=\"9\"\u003e\u003csup\u003ea\u003c/sup\u003e Below the LOQ\u003c/td\u003e\n\u003c/tr\u003e\n\u003c/tfoot\u003e\n\u003c/table\u003e\n\u003c/div\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec11\" class=\"Section2\"\u003e\n\u003cp\u003e\u003cstrong\u003eColor analysis\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe color parameters of SS during stir-fry processing in this experiment are shown in Table\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e4\u003c/span\u003e. It was apparent that the \u003cem\u003eL\u003c/em\u003e\u003csup\u003e*\u003c/sup\u003e, \u003cem\u003ea\u003c/em\u003e\u003csup\u003e*\u003c/sup\u003e and \u003cem\u003eb\u003c/em\u003e\u003csup\u003e*\u003c/sup\u003e values decreased gradually, and the corresponding sample powder changed from brown to black.\u003c/p\u003e\n\u003cp\u003eThe color of CMMs is an important parameter to evaluate the processing degree. Modern analytical methods have validated that there is a close correlation between marker components and the color of CMMs [\u003cspan class=\"CitationRef\"\u003e24\u003c/span\u003e, \u003cspan class=\"CitationRef\"\u003e32\u003c/span\u003e]. However, there have been limited scientific data and theoretical bases to validate the relationships between color and the quality of CMMs. Considering that the color indicates that a CMM reaches a certain processing state, could color parameters be used as surrogates of changes in chemical constituents during processing?\u003c/p\u003e\n\u003cdiv class=\"gridtable\"\u003e\n\u003ctable id=\"Tab4\" border=\"1\"\u003e\u003ccaption\u003e\n\u003cdiv class=\"CaptionNumber\"\u003eTable 4\u003c/div\u003e\n\u003cdiv class=\"CaptionContent\"\u003e\n\u003cp\u003eThe color measurement values of the Schizonepetae Spica samples subjected to the three processing temperatures over time (\u003cem\u003en\u003c/em\u003e\u0026thinsp;=\u0026thinsp;3)\u003c/p\u003e\n\u003c/div\u003e\n\u003c/caption\u003e\n\u003cthead\u003e\n\u003ctr\u003e\n\u003cth align=\"left\"\u003e\n\u003cp\u003eNo.\u003c/p\u003e\n\u003c/th\u003e\n\u003cth align=\"left\"\u003e\n\u003cp\u003e\u003cem\u003eL\u003c/em\u003e\u003csup\u003e*\u003c/sup\u003e\u003c/p\u003e\n\u003c/th\u003e\n\u003cth align=\"left\"\u003e\n\u003cp\u003e\u003cem\u003ea\u003c/em\u003e\u003csup\u003e*\u003c/sup\u003e\u003c/p\u003e\n\u003c/th\u003e\n\u003cth align=\"left\"\u003e\n\u003cp\u003e\u003cem\u003eb\u003c/em\u003e\u003csup\u003e*\u003c/sup\u003e\u003c/p\u003e\n\u003c/th\u003e\n\u003c/tr\u003e\n\u003c/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e1\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e40.45\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e2.73\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e5.61\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e2\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e35.14\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e2.49\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e1.49\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e3\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e34.62\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e2.51\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e1.12\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e4\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e34.08\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e2.33\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.60\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e5\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e34.41\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e2.36\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.75\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e6\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e34.30\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e2.39\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.62\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e7\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e34.40\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e2.40\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.62\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e8\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e33.33\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e1.96\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e-0.47\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e9\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e33.10\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e1.86\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e-0.82\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e10\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e33.09\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e1.90\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e-0.74\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e11\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e32.65\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e1.91\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e-0.80\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e12\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e32.62\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e1.77\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e-1.07\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e13\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e32.70\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e1.79\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e-1.16\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e14\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e33.06\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e1.80\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e-0.79\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e15\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e32.83\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e1.78\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e-1.14\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e16\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e33.09\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e1.68\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e-0.89\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e17\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e32.87\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e1.62\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e-1.29\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e18\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e32.54\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e1.66\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e-1.18\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e19\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e32.56\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e1.65\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e-1.24\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003c/tbody\u003e\n\u003c/table\u003e\n\u003c/div\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec12\" class=\"Section2\"\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCorrelation analysis\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe correlations between the color parameters and chemical marker contents during the stir-fry processing of SS were investigated. The Pearson correlation coefficients and corresponding \u003cem\u003ep\u003c/em\u003e-values in two sets of variables are listed in Table\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e5\u003c/span\u003e. Significantly positive correlations were observed between the contents of four major ingredients (luteolin-7-O-\u003cem\u003e\u0026beta;\u003c/em\u003e-D-glucoside, apigenin-7-O-\u003cem\u003e\u0026beta;\u003c/em\u003e-D-glucoside, hesperidin and rosmarinic acid) and the \u003cem\u003eL\u003c/em\u003e\u003csup\u003e*\u003c/sup\u003e, \u003cem\u003ea\u003c/em\u003e\u003csup\u003e*\u003c/sup\u003e and \u003cem\u003eb\u003c/em\u003e\u003csup\u003e*\u003c/sup\u003e values. The levels of another two main components (luteolin and apigenin) were found to be significantly and positively correlated with \u003cem\u003ea\u003c/em\u003e\u003csup\u003e*\u003c/sup\u003e. However, the amounts of luteolin and apigenin had no significant correlation with \u003cem\u003eL\u003c/em\u003e\u003csup\u003e*\u003c/sup\u003e and \u003cem\u003eb\u003c/em\u003e\u003csup\u003e*\u003c/sup\u003e. Previous reports have shown that there is a certain correlation between the color parameters and chemical compositions in CMMs during the course of processing [\u003cspan class=\"CitationRef\"\u003e33\u003c/span\u003e\u0026ndash;\u003cspan class=\"CitationRef\"\u003e36\u003c/span\u003e]. In this study, the three color parameters were associated significantly with the contents of luteolin-7-O-\u003cem\u003e\u0026beta;\u003c/em\u003e-D-glucoside, apigenin-7-O-\u003cem\u003e\u0026beta;\u003c/em\u003e-D-glucoside, hesperidin and rosmarinic acid, whereas \u003cem\u003ea\u003c/em\u003e\u003csup\u003e*\u003c/sup\u003e was most significantly correlated with the luteolin and apigenin contents.\u003c/p\u003e\n\u003cdiv class=\"gridtable\"\u003e\n\u003ctable id=\"Tab5\" border=\"1\"\u003e\u003ccaption\u003e\n\u003cdiv class=\"CaptionNumber\"\u003eTable 5\u003c/div\u003e\n\u003cdiv class=\"CaptionContent\"\u003e\n\u003cp\u003ePearson correlation analysis results between the color parameters and chemical marker contents during the stir-fry processing of Schizonepetae Spica\u003c/p\u003e\n\u003c/div\u003e\n\u003c/caption\u003e\n\u003cthead\u003e\n\u003ctr\u003e\n\u003cth rowspan=\"2\" align=\"left\"\u003e\n\u003cp\u003eCompound\u003c/p\u003e\n\u003c/th\u003e\n\u003cth colspan=\"2\" align=\"left\"\u003e\n\u003cp\u003e\u003cem\u003eL\u003c/em\u003e\u003csup\u003e*\u003c/sup\u003e\u003c/p\u003e\n\u003c/th\u003e\n\u003cth align=\"left\"\u003e\u0026nbsp;\u003c/th\u003e\n\u003cth colspan=\"2\" align=\"left\"\u003e\n\u003cp\u003e\u003cem\u003ea\u003c/em\u003e\u003csup\u003e*\u003c/sup\u003e\u003c/p\u003e\n\u003c/th\u003e\n\u003cth align=\"left\"\u003e\u0026nbsp;\u003c/th\u003e\n\u003cth colspan=\"2\" align=\"left\"\u003e\n\u003cp\u003e\u003cem\u003eb\u003c/em\u003e\u003csup\u003e*\u003c/sup\u003e\u003c/p\u003e\n\u003c/th\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003cth align=\"left\"\u003e\n\u003cp\u003e\u003cem\u003er\u003c/em\u003e\u003c/p\u003e\n\u003c/th\u003e\n\u003cth align=\"left\"\u003e\n\u003cp\u003e\u003cem\u003eP\u003c/em\u003e\u003c/p\u003e\n\u003c/th\u003e\n\u003cth align=\"left\"\u003e\u0026nbsp;\u003c/th\u003e\n\u003cth align=\"left\"\u003e\n\u003cp\u003e\u003cem\u003er\u003c/em\u003e\u003c/p\u003e\n\u003c/th\u003e\n\u003cth align=\"left\"\u003e\n\u003cp\u003e\u003cem\u003eP\u003c/em\u003e\u003c/p\u003e\n\u003c/th\u003e\n\u003cth align=\"left\"\u003e\u0026nbsp;\u003c/th\u003e\n\u003cth align=\"left\"\u003e\n\u003cp\u003e\u003cem\u003er\u003c/em\u003e\u003c/p\u003e\n\u003c/th\u003e\n\u003cth align=\"left\"\u003e\n\u003cp\u003e\u003cem\u003eP\u003c/em\u003e\u003c/p\u003e\n\u003c/th\u003e\n\u003c/tr\u003e\n\u003c/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eLuteolin-7-O-\u003cem\u003e\u0026beta;\u003c/em\u003e-D-glucoside\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e0.985\u003csup\u003e###a\u003c/sup\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.000\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e0.854\u003csup\u003e###\u003c/sup\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.000\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.991\u003csup\u003e###\u003c/sup\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.000\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eApigenin-7-O-\u003cem\u003e\u0026beta;\u003c/em\u003e-D-glucoside\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e0.945\u003csup\u003e###\u003c/sup\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.000\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e0.917\u003csup\u003e###\u003c/sup\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.000\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.972\u003csup\u003e###\u003c/sup\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.000\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eHesperidin\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e0.840\u003csup\u003e###\u003c/sup\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.000\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e0.922\u003csup\u003e###\u003c/sup\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.000\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.883\u003csup\u003e###\u003c/sup\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.000\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eRosmarinic acid\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e0.836\u003csup\u003e###\u003c/sup\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.000\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e0.965\u003csup\u003e###\u003c/sup\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.000\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.887\u003csup\u003e###\u003c/sup\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.000\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eLuteolin\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e0.165\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.499\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e0.659\u003csup\u003e##b\u003c/sup\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.002\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.269\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.266\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eApigenin\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e0.151\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.537\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e0.687\u003csup\u003e##\u003c/sup\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.001\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.268\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.268\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003c/tbody\u003e\n\u003ctfoot\u003e\n\u003ctr\u003e\n\u003ctd colspan=\"9\"\u003e\u003csup\u003ea\u003c/sup\u003e Correlation is significant at the 0.001 level\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd colspan=\"9\"\u003e\u003csup\u003eb\u003c/sup\u003e Correlation is significant at the 0.01 level\u003c/td\u003e\n\u003c/tr\u003e\n\u003c/tfoot\u003e\n\u003c/table\u003e\n\u003c/div\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec13\" class=\"Section2\"\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eRegression analysis\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eTo date, a series of quality control methods focusing on the essential oil of SS have been reported, including steam distillation, gas chromatography-mass spectrometry (GC-MS) and fingerprinting [\u003cspan class=\"CitationRef\"\u003e37\u003c/span\u003e, \u003cspan class=\"CitationRef\"\u003e38\u003c/span\u003e]. However, there are few reports regarding the determination of nonvolatile constituents from raw and processed SS. Additionally, laboratory instruments such as HPLC could provide accurate measurement results of marker compounds in SS during processing. However, these methods involve laborious, complex and time-consuming pretreatment of samples with extensive use of organic reagents that are unfriendly to the environment. Therefore, possible models of surrogate color parameters for marker constituents in SS during processing will be explored. According to the above results of correlation analysis, color analysis and the variation in the major constituents of SS during processing, statistically significant parameters (\u003cem\u003eL\u003c/em\u003e\u003csup\u003e*\u003c/sup\u003e, \u003cem\u003ea\u003c/em\u003e\u003csup\u003e*\u003c/sup\u003e and \u003cem\u003eb\u003c/em\u003e\u003csup\u003e*\u003c/sup\u003e) were analyzed by the enter linear regression method to establish the regression model of luteolin-7-O-\u003cem\u003e\u0026beta;\u003c/em\u003e-D-glucoside, apigenin-7-O-\u003cem\u003e\u0026beta;\u003c/em\u003e-D-glucoside, hesperidin and rosmarinic acid. The optimal models were determined according to the maximum adjusted \u003cem\u003eR\u003c/em\u003e\u003csup\u003e2\u003c/sup\u003e values (Table\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e6\u003c/span\u003e). The best individual regression models were established as follows:\u003c/p\u003e\n\u003cp\u003e\u003cem\u003eLuteolin-7-O-\u003c/em\u003e\u0026beta;\u003cem\u003e-D-glucoside\u003c/em\u003e = -0.604\u0026thinsp;+\u0026thinsp;0.019\u0026middot;\u003cem\u003eL\u003c/em\u003e\u003csup\u003e*\u003c/sup\u003e + 0.014\u0026middot;\u003cem\u003ea\u003c/em\u003e\u003csup\u003e*\u003c/sup\u003e + 0.03\u0026middot;\u003cem\u003eb\u003c/em\u003e\u003csup\u003e*\u003c/sup\u003e (1)\u003c/p\u003e\n\u003cp\u003e\u003cem\u003eApigenin-7-O-\u0026beta;-D-glucoside\u003c/em\u003e = -0.361\u0026thinsp;+\u0026thinsp;0.009\u0026middot;\u003cem\u003eL\u003c/em\u003e\u003csup\u003e*\u003c/sup\u003e + 0.066\u0026middot;\u003cem\u003ea\u003c/em\u003e\u003csup\u003e*\u003c/sup\u003e + 0.018\u0026middot;\u003cem\u003eb\u003c/em\u003e\u003csup\u003e*\u003c/sup\u003e (2)\u003c/p\u003e\n\u003cp\u003e\u003cem\u003eHesperidin\u003c/em\u003e = -11.237\u0026thinsp;+\u0026thinsp;0.275\u0026middot;\u003cem\u003eL\u003c/em\u003e\u003csup\u003e*\u003c/sup\u003e + 1.35\u0026middot;\u003cem\u003ea\u003c/em\u003e\u003csup\u003e*\u003c/sup\u003e \u0026minus;\u0026thinsp;0.256\u0026middot;\u003cem\u003eb\u003c/em\u003e\u003csup\u003e*\u003c/sup\u003e (3)\u003c/p\u003e\n\u003cp\u003e\u003cem\u003eRosmarinic acid\u003c/em\u003e = -7.354\u0026thinsp;+\u0026thinsp;0.179\u0026middot;\u003cem\u003eL\u003c/em\u003e\u003csup\u003e*\u003c/sup\u003e + 0.833\u0026middot;\u003cem\u003ea\u003c/em\u003e\u003csup\u003e*\u003c/sup\u003e \u0026minus;\u0026thinsp;0.208\u0026middot;\u003cem\u003eb\u003c/em\u003e\u003csup\u003e*\u003c/sup\u003e (4)\u003c/p\u003e\n\u003cp\u003eFor luteolin and apigenin, third-order polynomial curve fitting was performed for the data of each sample. The SPSS analysis process excluded \u003cem\u003ea\u003c/em\u003e\u003csup\u003e*2\u003c/sup\u003e as an unimportant factor, and the formulas and adjusted \u003cem\u003eR\u003c/em\u003e\u003csup\u003e2\u003c/sup\u003e values (Table\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e6\u003c/span\u003e) were determined as follows:\u003c/p\u003e\n\u003cp\u003e\u003cem\u003eLuteolin\u003c/em\u003e = -2.977\u0026thinsp;+\u0026thinsp;2.217\u0026middot;\u003cem\u003ea\u003c/em\u003e\u003csup\u003e*\u003c/sup\u003e \u0026minus;\u0026thinsp;0.146\u0026middot;\u003cem\u003ea\u003c/em\u003e\u003csup\u003e*3\u003c/sup\u003e (5)\u003c/p\u003e\n\u003cp\u003e\u003cem\u003eApigenin\u003c/em\u003e = -1.562\u0026thinsp;+\u0026thinsp;1.154\u0026middot;\u003cem\u003ea\u003c/em\u003e\u003csup\u003e*\u003c/sup\u003e \u0026minus;\u0026thinsp;0.074\u0026middot;\u003cem\u003ea\u003c/em\u003e\u003csup\u003e*3\u003c/sup\u003e (6)\u003c/p\u003e\n\u003cp\u003eThe ANOVA test results of coefficient values, standard errors and \u003cem\u003et\u003c/em\u003e-values for the color parameters included in each proposed model are presented in Table\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e7\u003c/span\u003e. These results showed that the contents of 6 marker constituents could be represented well by polynomials of the color parameters, including \u003cem\u003eL\u003c/em\u003e\u003csup\u003e*\u003c/sup\u003e, \u003cem\u003ea\u003c/em\u003e\u003csup\u003e*\u003c/sup\u003e and \u003cem\u003eb\u003c/em\u003e\u003csup\u003e*\u003c/sup\u003e. The models were statistically significant \u003cem\u003e(p\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.000), with adjusted \u003cem\u003eR\u003c/em\u003e\u003csup\u003e2\u003c/sup\u003e values greater than 0.800, which indicated that good correlations were established between the color parameters and concentrations of different marker compounds. Thus, the contents of marker constituents of SS could be rapidly predicted by color parameters during processing, which represented the scientific elucidation of color as an important indicator for the identification of SS processing degree. However, a unified quantitative relationship between the color parameters and chemical marker contents for various SS samples could not be established because of the differences in a number of factors\u0026mdash;such as plant cultivars, harvesting time, degradation degrees and many other poorly controlled aspects during stir-fry processing. Nevertheless, it is possible to develop specific prediction models for marker compounds in specific SS samples to monitor the degree of processing using color parameters. Further studies are warranted to establish the relationship between the alteration of color parameters and the changes in medicinal properties during processing.\u003c/p\u003e\n\u003cdiv class=\"gridtable\"\u003e\n\u003ctable id=\"Tab6\" border=\"1\"\u003e\u003ccaption\u003e\n\u003cdiv class=\"CaptionNumber\"\u003eTable 6\u003c/div\u003e\n\u003cdiv class=\"CaptionContent\"\u003e\n\u003cp\u003eStatistical evaluation for the prediction models\u003c/p\u003e\n\u003c/div\u003e\n\u003c/caption\u003e\n\u003cthead\u003e\n\u003ctr\u003e\n\u003cth align=\"left\"\u003e\n\u003cp\u003eCompound\u003c/p\u003e\n\u003c/th\u003e\n\u003cth align=\"left\"\u003e\n\u003cp\u003e\u003cem\u003eR\u003c/em\u003e\u003c/p\u003e\n\u003c/th\u003e\n\u003cth align=\"left\"\u003e\n\u003cp\u003e\u003cem\u003eR\u003c/em\u003e\u003csup\u003e2\u003c/sup\u003e\u003c/p\u003e\n\u003c/th\u003e\n\u003cth align=\"left\"\u003e\n\u003cp\u003eAdjusted \u003cem\u003eR\u003c/em\u003e\u003csup\u003e2\u003c/sup\u003e\u003c/p\u003e\n\u003c/th\u003e\n\u003cth align=\"left\"\u003e\n\u003cp\u003e\u003cem\u003eF\u003c/em\u003e\u003c/p\u003e\n\u003c/th\u003e\n\u003cth align=\"left\"\u003e\n\u003cp\u003e\u003cem\u003eP\u003c/em\u003e\u003c/p\u003e\n\u003c/th\u003e\n\u003c/tr\u003e\n\u003c/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eLuteolin-7-O-\u003cem\u003e\u0026beta;\u003c/em\u003e-D-glucoside\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.991\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.983\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.980\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e289.785\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.000\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eApigenin-7-O-\u003cem\u003e\u0026beta;\u003c/em\u003e-D-glucoside\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.982\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.965\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.958\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e137.046\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.000\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eHesperidin\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.938\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.880\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.856\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e36.758\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.000\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eRosmarinic acid\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.974\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.948\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.938\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e91.242\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.000\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eLuteolin\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.971\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.942\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.935\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e129.771\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.000\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eApigenin\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.910\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.828\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.807\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e38.570\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.000\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e\n\u003c/div\u003e\n\u003cdiv class=\"gridtable\"\u003e\n\u003ctable id=\"Tab7\" border=\"1\"\u003e\u003ccaption\u003e\n\u003cdiv class=\"CaptionNumber\"\u003eTable 7\u003c/div\u003e\n\u003cdiv class=\"CaptionContent\"\u003e\n\u003cp\u003eRegression analysis coefficients for the prediction models\u003c/p\u003e\n\u003c/div\u003e\n\u003c/caption\u003e\n\u003cthead\u003e\n\u003ctr\u003e\n\u003cth align=\"left\"\u003e\n\u003cp\u003eCompound\u003c/p\u003e\n\u003c/th\u003e\n\u003cth align=\"left\"\u003e\n\u003cp\u003eVariable\u003c/p\u003e\n\u003c/th\u003e\n\u003cth align=\"left\"\u003e\n\u003cp\u003eCoefficient value\u003c/p\u003e\n\u003c/th\u003e\n\u003cth align=\"left\"\u003e\n\u003cp\u003eStandard error\u003c/p\u003e\n\u003c/th\u003e\n\u003cth align=\"left\"\u003e\n\u003cp\u003e\u003cem\u003eT\u003c/em\u003e-value\u003c/p\u003e\n\u003c/th\u003e\n\u003cth align=\"left\"\u003e\n\u003cp\u003eSig.\u003c/p\u003e\n\u003c/th\u003e\n\u003c/tr\u003e\n\u003c/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eLuteolin-7-O-\u003cem\u003e\u0026beta;\u003c/em\u003e-D-glucoside\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eConstant\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e-0.604\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e-0.799\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.437\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e\u003cem\u003eL\u003c/em\u003e\u003csup\u003e*\u003c/sup\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.019\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.397\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.935\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.365\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e\u003cem\u003ea\u003c/em\u003e\u003csup\u003e*\u003c/sup\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.014\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.055\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.426\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.676\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e\u003cem\u003eb\u003c/em\u003e\u003csup\u003e*\u003c/sup\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.030\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.550\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e1.060\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.306\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eApigenin-7-O-\u003cem\u003e\u0026beta;\u003c/em\u003e-D-glucoside\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eConstant\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e-0.361\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e-0.432\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.672\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e\u003cem\u003eL\u003c/em\u003e\u003csup\u003e*\u003c/sup\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.009\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.227\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.371\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.716\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e\u003cem\u003ea\u003c/em\u003e\u003csup\u003e*\u003c/sup\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.066\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.344\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e1.860\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.083\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e\u003cem\u003eb\u003c/em\u003e\u003csup\u003e*\u003c/sup\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.018\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.447\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.598\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.559\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eHesperidin\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eConstant\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e-11.237\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e-0.887\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.389\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e\u003cem\u003eL\u003c/em\u003e\u003csup\u003e*\u003c/sup\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.275\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.895\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.793\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.440\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e\u003cem\u003ea\u003c/em\u003e\u003csup\u003e*\u003c/sup\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e1.350\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.863\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e2.528\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.023\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e\u003cem\u003eb\u003c/em\u003e\u003csup\u003e*\u003c/sup\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e-0.256\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e-0.756\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e-0.548\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.592\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eRosmarinic acid\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eConstant\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e-7.354\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e-1.831\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.087\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e\u003cem\u003eL\u003c/em\u003e\u003csup\u003e*\u003c/sup\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.179\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e1.207\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e1.624\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.125\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e\u003cem\u003ea\u003c/em\u003e\u003csup\u003e*\u003c/sup\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.833\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e1.107\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e4.921\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.000\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e\u003cem\u003eb\u003c/em\u003e\u003csup\u003e*\u003c/sup\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e-0.208\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e-1.273\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e-1.400\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.182\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eLuteolin\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eConstant\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e-2.977\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e-12.710\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.000\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e\u003cem\u003ea\u003c/em\u003e\u003csup\u003e*\u003c/sup\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e2.217\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e6.700\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e13.034\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.000\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e\u003cem\u003ea\u003c/em\u003e\u003csup\u003e*3\u003c/sup\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e-0.146\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e-6.083\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e-11.834\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.000\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eApigenin\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eConstant\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e-1.562\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e-6.386\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.000\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e\u003cem\u003ea\u003c/em\u003e\u003csup\u003e*\u003c/sup\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e1.154\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e5.747\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e6.500\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.000\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e\u003cem\u003ea\u003c/em\u003e\u003csup\u003e*3\u003c/sup\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e-0.074\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e-5.096\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e-5.763\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.000\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e\n\u003c/div\u003e\n\u003c/div\u003e"},{"header":"Conclusions","content":"\u003cp\u003eFlavonoids and organic acids are the main nonvolatile constituents of SS, and they possess many pharmacological activities. The present study examined variations in the levels of six marker nonvolatile constituents and the color parameters of SS during stir-fry processing by using HPLC-DAD and colorimetry, respectively. The amounts of the four major ingredients (luteolin-7-O-\u003cem\u003eβ\u003c/em\u003e-D-glucoside, apigenin-7-O-\u003cem\u003eβ\u003c/em\u003e-D-glucoside, hesperidin and rosmarinic acid) and the three color parameters (\u003cem\u003eL\u003c/em\u003e\u003csup\u003e*\u003c/sup\u003e, \u003cem\u003ea\u003c/em\u003e\u003csup\u003e*\u003c/sup\u003e and \u003cem\u003eb\u003c/em\u003e\u003csup\u003e*\u003c/sup\u003e) decreased with increasing temperature over time, whereas the contents of another two main components (luteolin and apigenin) initially increased before reaching a plateau and then decreased during processing. \u003cem\u003eL\u003c/em\u003e\u003csup\u003e*\u003c/sup\u003e, \u003cem\u003ea\u003c/em\u003e\u003csup\u003e*\u003c/sup\u003e and \u003cem\u003eb\u003c/em\u003e\u003csup\u003e*\u003c/sup\u003e were recognized as the relevant parameters significantly associated with the luteolin-7-O-\u003cem\u003eβ\u003c/em\u003e-D-glucoside, apigenin-7-O-\u003cem\u003eβ\u003c/em\u003e-D-glucoside, hesperidin and rosmarinic acid contents in SS, while \u003cem\u003ea\u003c/em\u003e\u003csup\u003e*\u003c/sup\u003e was most significantly related to the luteolin and apigenin contents in SS. By regression analysis, four optimal multiple linear regression models and two third-order polynomial models were established for the corresponding marker compounds as a function of relevant color parameters, with an adjusted \u003cem\u003eR\u003c/em\u003e\u003csup\u003e2\u003c/sup\u003e value significantly greater than 0.800. For the first time, surrogate prediction using color parameters was developed for the simultaneous quantification of 6 marker substances including flavonoids and an organic acid during the processing of SS. Although these models could not be applied to various SS samples, the chemical marker contents could be rapidly predicted by the color parameters through the specific models. In short, colorimeter sensor technology and phytochemical analysis combined with chemometric methods provided scientific data and a theoretical basis to validate the relationships between color features and the processing degree of SS. The developed strategy offers new clues for the quality control standards of nonvolatile constituents of SS processing practices and provides useful references for other processing methods.\u003c/p\u003e"},{"header":"Abbreviations","content":"\u003cp\u003eCIE, International Commission on Illumination; CMM, Chinese medicinal material; DAD, diode array detector; SS, Schizonepetae Spica; SSC, Schizonepetae Spica Carbonisata; TCM, traditional Chinese medicine\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eAcknowledgements\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNot applicable.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthors\u0026rsquo; contributions\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eHC and XL conceived and designed the experiments. XL performed the experiment and prepared the manuscript. HC, MW, YZ and ZM revised the manuscript. All authors have read and agreed to the published version of the manuscript.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis work was supported by the Research Project of Drug Standardization of National Pharmacopoeia Committee (2018Z006) and the 6\u003csup\u003eth\u003c/sup\u003e National Academic Experience Inheritance Program of Famous Chinese Medicine Experts (Prof. Hui Cao) (No. 176-2017-XMZC-0166-01).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAvailability of data and materials\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe datasets used during this study are available from the corresponding author upon reasonable request.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eEthics approval and consent to participate\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNot applicable.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent for publication\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNot applicable.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompeting interests\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors declare that they have no competing interests.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthor details\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003csup\u003e1 \u003c/sup\u003eResearch Center for Traditional Chinese Medicine of Lingnan (Southern China), Jinan University, Guangzhou 510632, China. \u003csup\u003e2 \u003c/sup\u003eNational Engineering Research Center for Modernization of Traditional Chinese Medicine Lingnan Resources Branch, Guangzhou 510632, Guangdong, China.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eZhao ZZ, Liang ZT, Chan K, Lu GH, Lee ELM, Chen HB, et al. 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Plos One. 2020;15(1):1-15.\u003c/li\u003e\n\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"Color identification, Schizonepetae Spica, Stir-fry processing, Correlation analysis, Regression analysis","lastPublishedDoi":"10.21203/rs.3.rs-414931/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-414931/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003e\u003cstrong\u003eBackground:\u003c/strong\u003e Color is an important method of authentication to evaluate the degree of Chinese medicinal material (CMM) processing. This traditional color description used for identification needs to be confirmed by modern scientific analysis. Schizonepetae Spica (SS), the dried spike of\u003cem\u003e Schizonepeta tenuifolia \u003c/em\u003eBriq., is a traditional Chinese medicinal herb. Raw SS has the actions of dispelling the common cold and fever. Schizonepetae Spica Carbonisata (SSC; raw SS processed by stir-frying until the surface becomes blackish-brown and the interior turns dark yellow) has particularly strong efficacy in arresting bleeding from bloody stool and metrorrhagia. \u003c/p\u003e\u003cp\u003e\u003cstrong\u003eMethods:\u003c/strong\u003e In this paper, a high-performance liquid chromatography-diode array detector method and colorimetry were employed to determine 6 nonvolatile marker constituents and the color parameters (\u003cem\u003eL\u003c/em\u003e\u003csup\u003e*\u003c/sup\u003e, \u003cem\u003ea\u003c/em\u003e\u003csup\u003e*\u003c/sup\u003e and \u003cem\u003eb\u003c/em\u003e\u003csup\u003e*\u003c/sup\u003e) of SS during stir-fry processing, respectively. \u003c/p\u003e\u003cp\u003e\u003cstrong\u003eResults: \u003c/strong\u003eAccording to Pearson correlation analysis,\u003cem\u003e L\u003c/em\u003e\u003csup\u003e*\u003c/sup\u003e, \u003cem\u003ea\u003c/em\u003e\u003csup\u003e*\u003c/sup\u003e and \u003cem\u003eb\u003c/em\u003e\u003csup\u003e*\u003c/sup\u003e showed significant correlations with the levels of luteolin-7-O-\u003cem\u003eβ\u003c/em\u003e-D-glucoside, apigenin-7-O-\u003cem\u003eβ\u003c/em\u003e-D-glucoside, hesperidin and rosmarinic acid, while \u003cem\u003ea\u003c/em\u003e\u003csup\u003e* \u003c/sup\u003ewas significantly correlated with the amounts of luteolin and apigenin. The corresponding regression models were good fits for the color parameters as respective functions of the 6 marker constituents according to enter multiple linear regression and third-order polynomial curve fitting methods (adjusted \u003cem\u003eR\u003c/em\u003e\u003csup\u003e2\u003c/sup\u003e \u0026gt; 0.800). \u003cstrong\u003eConclusion: \u003c/strong\u003eSurrogate prediction of marker compounds using color parameters provides a valuable and cost-saving tool for rapid or online monitoring of the processing degree of SS. Raw SS and SSC could be determined based on the color parameters and 6 marker constituent contents for a comprehensive quality evaluation for the first time. This paper provides scientific data to validate the relationships between color features and quality during the processing of SS.\u003c/p\u003e","manuscriptTitle":"Colorimetric parameters correlated with the variation in the marker constituent contents during the stir-fry processing of Schizonepetae Spica","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2021-04-14 23:06:17","doi":"10.21203/rs.3.rs-414931/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"1f2b153a-dd83-4523-8130-178a63567c97","owner":[],"postedDate":"April 14th, 2021","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[{"id":3639816,"name":"Materials Chemistry"}],"tags":[],"updatedAt":"2022-01-13T17:48:46+00:00","versionOfRecord":{"articleIdentity":"rs-414931","link":"https://doi.org/10.1007/s12161-021-02156-4","journal":{"identity":"food-analytical-methods","isVorOnly":false,"title":"Food Analytical Methods"},"publishedOn":"2022-01-13 17:48:46","publishedOnDateReadable":"January 13th, 2022"},"versionCreatedAt":"2021-04-14 23:06:17","video":"","vorDoi":"10.1007/s12161-021-02156-4","vorDoiUrl":"https://doi.org/10.1007/s12161-021-02156-4","workflowStages":[]},"version":"v1","identity":"rs-414931","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-414931","identity":"rs-414931","version":["v1"]},"buildId":"7rjqhiLT3MXkJMwkYKINL","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}