Kinetics of the Growth and the Degradation of Lycopene and Vitamin C in Tomato slurry

Kinetics of the Growth and the Degradation of Lycopene and Vitamin C in Tomato slurry | 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 Article Kinetics of the Growth and the Degradation of Lycopene and Vitamin C in Tomato slurry ANANDI MAHARABAM, Nanao Singh Keisham, Giri Soibam This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-8505192/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract The present work focuses on the kinetics of both growth and degradation of lycopene and Vitamin C in tomato ( Solanum Peruvianum L) during the various cooking methods - Simple boiling, steaming, frying, microwave and pressure cooking. In our study, the effect of oxidation and light were negligible by covering the bowl containing tomato slurry with aluminium foil and the samples in triplicate were pulled out after every fixed interval of time set different for all cooking methods. The growth and degradation of lycopene concentration were found to obey zeroth order and first order kinetics while the degradation of Vitamic C obeys first order kinetics. The maximum lycopene extraction in all cooking methods is nearly same irrespective of different growth reaction rate values. The reaction rate constant (during growth) is larger than that for lycopene degradation, so lycopene degradation is seen after growth of lycopene stops. Degradation of lycopene is mainly through isomerization. Chemical effect of oil acts synergistically to heating effect during frying. It is found that Vitamin C is not associated with breaking of tomato tissue but only degrades in all cooking methods following first order kinetics. Tomato Cooking Lycopene Vitamin C Kinetics order Figures Figure 1 Figure 2 Figure 3 Figure 4 Highlight of research work · Lycopene growth follows zeroth order during cooking. · Maximum lycopene extraction in all cooking methods is nearly same irrespective of reaction rate values. · Reaction rate for Lycopene degradation is smaller than for growth so degradation is seen after its growth stops. · Main mechanism for Lycopene degradation in all cooking methods is through isomerization. · Vitamin C is not related to breaking of tissue but only degrades following a first order kinetics. 1. Introduction Antioxidants like lycopene and Vitamin C (Marin et al. 2004, Rissanen et al. 2002 ) are found naturally in tomato (Lycopersicon Esculentum Mill) and other vegetables. These natural antioxidants exist, generally, in combination and might act synergistically (Fuhrman et al. 2000 ). The specific biological properties of lycopene have been attributed to its unique structural and chemical features (Clinton 1998 ); and these properties may, further, be enhanced by the presence of other active antioxidants such as β -carotene, vitamin E, and vitamin C. Lycopene (C 40 H 56 ) has a molecular weight of 536.85 g/mol. There are more than 72 lycopene isomers, with all-trans-lycopene being the most important (Zechmeister et al. 1943 ). The food items containing lycopene are consumed directly as raw or through processed food items. The stability of nutrients during processing depends on the nature of the commodity as well as on the severity of the processing. There are many reports on the increase or decrease of the lycopene content during the various processing of the food. For instance, it was reported that there was reduction in lycopene concentration during thermal treatment (Luterotti et al. 2015) in commercial double concentrated tomato puree, while a contrary report was given by Dewanto et al. ( 2002 ) in the lycopene extracted from fresh cooked tomato slurry. In another case, Takeoka et al. ( 2001 ) had reported that the processing of fresh tomatoes into paste caused the concentration of total lycopene to decrease by 9 to 28% while others (Graziani et al. 2003 ; Re et al.2002) had given a contrasting report that heating or processing tomatoes at higher temperature facilitates the increase in concentration of lycopene. It is known that lycopene concentration is sensitive to heat, light, oxygen, and metal ions (Lavelli and Torresani 2011 ; Scita 1992); and may undergo (trans–cis) isomerization, structural rearrangements or/and chemical reactions like oxidation (Gómez-Prieto et al. 2003 ; Demiray et al. 2013 ). For example, heat treatments favour trans – cis isomeric conversion of lycopene while light irradiation induced cis-isomer degradation (Chen et al. 2009 ; Shi et al. 2008 ). In one report temperatures between 75–100°C favoured enhancing lycopene isomerisation during storage (Hackett et al. 2004 ); but Agarwal et al. ( 2001 ) have given a contrasting report that the storage temperature has no significant effect on concentration of lycopene in commercially canned tomato juice. All such divergent reports could be due to combined effect of two or more factors affecting lycopene concentration or on the type of lycopene base food materials. The relative change (increase or decrease) in lycopene concentration may be different for different factors like temperature, pressure chemical effect, light, genetic factors etc.; for example, the destruction rate of lycopene has been reported to be faster during thermal processing than during other methods like high pressure processing (Tola, et al. 2015). Presence of certain constituents like - tocopherols, ascorbic acid, and phenolic compounds - in the tomatoes may help in stabilizing lycopene during food processing (Takeoka et al. 2001 ). So, it is possible to find divergent reports when many unnoticed factors come into play during the various food processing techniques. Since chemical kinetics provide a means to understand the mechanisms and the extent of chemical reactions in foods during storage and processing (van Boekel 2008 ), the main purpose of our present study is to understand the effect of cooking on the kinetics of both lycopene concentration and vitamin C concentration in tomato slurry. Also, we seek to understand the mechanism for such changes/reactions and discuss the significance of the results. In all our cooking methods, the effect due to oxidation and light were kept negligible so that the observed results could be related mainly to difference in heating rate associated with the cooking methods. The chemical effect of oil acting synergistically to heating rate during frying provide experimental evidence for combined effect of two factors affecting the kinetics of both lycopene and vitamin C concentration. 2. Materials and Methods 2.1. Collection of fruits and preparation of samples The mature red and ripe tomatoes were collected from local area of north Sekmai, Imphal West, Manipur, India. The tomato samples were identified as Solanum Peruvianum L. (wild tomatoes) (with VERN.NAME & USES as Khamen Ashinba Macha) in the DEPARTMENT OF LIFE SCIENCES, (BOTANY) MANIPUR UNIVERSITY, Canchipur, Manipur. Ripe tomatoes of similar sizes were selected and then washed thoroughly with tap water followed by distilled water and finally dried. The tomatoes were then crushed in a warring blender in order to obtain a uniform mixture. The final homogenizes mixture (or samples) so obtained were used in following experimental steps. 2.2 Determination of lycopene Lycopene content was determined, following the method given by Sadasivam and Manikam (1992). About 1g of homogenized sample was accurately weighed and was repeatedly extracted with acetone using a pestle and mortar until the residue become colourless. The extract was transferred in a separating funnel containing petroleum ether and then the sample was separated into two phases. Only the upper phase was collected and stored in amber coloured bottle. A small amount of sodium sulphate was added and absorbance was taken at 503 nm. The lycopene content was calculated using the formula: 𝐿𝑦𝑐𝑜𝑝𝑒𝑛𝑒 (𝑖𝑛 𝑚𝑔/100𝑔) = 3.1206 × 𝑂𝐷 𝑜𝑓 𝑠𝑎𝑚𝑝𝑙𝑒 × 𝑣𝑜𝑙. 𝑚𝑎𝑑𝑒 𝑢𝑝 ×100 / 𝑤𝑡. 𝑜𝑓 𝑠𝑎𝑚𝑝𝑙𝑒 × 1000 2.3. Determination of Vitamin C Vitamin C content was determined using the method given by Jayaraman (1985). In brief, weighed portion of the intact sample was extracted with sufficient volume of 5% metaphosphoric acid and 10% acetic acid solution. Then the extract was treated with activated charcoal. Next, 10% thiourea solution and 2,4 dinitrophenyl hydrazine reagents were added to the filtrate and water bathed for 3hrs and finally, it was cooled in ice water and 2ml of H2SO4 (85%) added dropwise. The colour of standard ascorbic acid was developed in a similar way. The results were read at 540nm. 2.4. Chemical Reagents All the chemicals and reagents used in the study were of analytical grade. 2.5. Statistical Analysis ANOVA analysis was employed to all the data obtained from the triplicate determination using Origin pro-8.5. The means that differed significantly were separated using Tukey’s Test. 3. Results and Discussion 3.1. Growth of lycopene In all the cooking methods, the lycopene content continues to increase till a maximum value and then the lycopene content decreases. It is observed that the value of maximum lycopene concentration for all the cooking methods was in a close range 9.22–11.35 mg/100g (except frying, which has a maximum value 17.18 mg/100g); however, the time taken (say T) for reaching the maximum concentration is different for all the cooking methods. The reason would be addressed in latter part of this section. The increase in lycopene concentration during cooking has also been reported in literature (Ishiwu et al. 2014). Figure 1 show the curves for the growth of lycopene concentration with time for all the different cooking methods. It may be noted that the kinetic analysis of the growth of lycopene concentration was not done by earlier workers to the best of our knowledge. In our present study, we have used the software origin 9.0 for analysis and fitting of the experimental data. The growth of lycopene concentration in all the cooking methods were found to follow zero order kinetics: $$\:\frac{C}{{C}_{o}}=kt$$ 1 where \(\:C\) is the concentration of lycopene at time 𝑡 and \(\:{C}_{o}\) is the concentration of lycopene at initial time and 𝑘 is reaction rate constant. In Fig. 2 , the straight lines show the fitted zeroth order kinetics for lycopene growth for cooking methods - simple boiling and steaming, with values of R 2 0.99285 and 0.91550 respectively. Similarly, the straight lines in Fig. 3 show the fitted zeroth order kinetics for lycopene growth for cooking methods - microwave, pressure cook and Pan Fry with values of R 2 0.99428, 0.94589 and 0.99851 respectively. The growth of lycopene content during cooking is definitely related to the breaking of the tissue and its release; had the breaking of the tissue be complete the maximum value of lycopene concentration in all the cooking methods would be almost same. Literature reports that cooking or shredding led to physical destruction or softening of the plant cell membranes and breakdown the lycopene-protein complexes (Hussein and el-Tohamy 1990 ), supports the reasoning given here. Chang et al. ( 2006 ) had also made the suggestion that thermal processes broke down cell walls and weakened the bonding forces between lycopene and the tissue matrix, thereby enhancing the release of phytochemicals from the matrix. In our study, the reaction rate constant for growth of lycopene concentration are different for all the cooking methods (Table 1 ); this suggest that the rate of breaking the tissue matrix and the release of lycopene is different for different cooking methods. The near values of maximum lycopene concentration in all the cooking methods suggest that the breaking of tomato matrix (due to applied heat) in all cooking methods (except frying) are of same degree, but for frying the breaking of the tissue and release of lycopene is highest. However, the time taken T for reaching maximum lycopene growth are different for all the cooking methods employed; this difference in values of T must be attributed mainly to the different values of growth reaction rate 𝑘. The breaking of tissue matrix due to heat alone may not be complete, but in frying the chemical effect of oil further add up and scale up the breaking of tissue matrix and hence more lycopene is released. From Table 1 , one may note that the reaction rate constant for the lycopene growth is greatest for pan fry, followed by microwave, pressure cook, boiling and then steaming. The different reaction rate (𝑘) values for growth of lycopene for different cooking methods suggest its implicit dependence on rate of heat given and additive chemical effect of oil. Thus, we see that microwave cooking method is most effective cooking method for maximum extraction of lycopene if only heat factor is considered. Table 1 Reaction rate constants and other kinetic parameters for growth (zeroth order kinetics) of lycopene and degradation of lycopene (first order kinetics) and vitamin C (first order kinetics) in tomatoes during different cooking methods Cooking method Growth of lycopene concentration Degradation of lycopene concentration Degradation of vitamin C concentration \(\:k\) (per min) R 2 D (in min) \(\:{t}_{1/2}\) (in min) \(\:{k}_{d}\) (per min) R 2 D (in min) \(\:{t}_{1/2}\) (in min) \(\:{k}_{d}\) (per min) R 2 Simple boiling 0.0588 0.99285 225.6 67.9 0.01021 0.99079 105.0 31.6 0.02195 0.97565 Steaming 0.0393 0.91550 221.6 66.7 0.01039 0.99269 110.2 33.2 0.02089 0.98866 Pan Fry 3.251 0.99851 10.6 3.2 0.21754 0.96966 15.2 4.6 0.15164 0.85367 Microwave 1.152 0.99428 22.0 6.6 0.1049 0.92505 18.4 5.5 0.12535 0.88918 Pressure Cook 0.744 0.94589 36.6 11.0 0.06281 0.98129 28.1 8.4 0.08208 0.89971 3.2. Degradation of lycopene concentration In all the cooking methods, the degradation of lycopene concentration can be seen after the lycopene concentration reached the maximum value. In the previous section, we have noted that the maximum lycopene concentrations for all the cooking methods were of near values and the time taken (T) for reaching the maximum concentration to be different. This difference in values of T was attributed mainly to the different values of growth reaction rate. As the lycopene concentration start decreasing from the maximum value, we shall take the initial lycopene concentration to be this maximum value and the analysis of lycopene degradation in latter part of cooking time would be carried out relative to T. In general, lycopene degradation follows first order kinetics. This may be shown in two ways – either by plotting the lycopene concentration against time or by plotting log (lycopene concentration) against time. The curve for concentration as a function of time is an exponential curve for first order kinetics while the curve for log (concentration) versus time is a straight line, which is easy to visualise. In our present analysis, we choose the second method by considering the log (lycopene concentration) as a function of time. As we have mentioned before that lycopene degradation begin only after attaining maximum concentration, we therefore make the modification of counting time relative to T. We have use the software origin 9.0 for fitting (technique of least square fitting) the experimental data with the theoretical curve; interestingly, the degradation of lycopene concentration for all the cooking methods obeyed first order kinetic reactions. In our analysis, we have used the following equation for first order kinetics: \(\:\text{ln}\left(\frac{C}{{C}_{o}}\right)={k}_{d}\left(t-T\right)\) (2), where 𝑡 is time; 𝐶 is concentration at time \(\:\left(t-T\right)\) and \(\:{C}_{o}\) is initial lycopene concentration at time T. The reaction rate constant ( \(\:{k}_{d})\) could be calculated using Eq. (2). A theoretical treatment for the loss of food quality as a function of time in terms of reaction order may also be found elsewhere (Petros et al 1997). Figure 4 depicts a representative plot of \(\:\text{ln}\left(\frac{C}{{C}_{o}}\right)\) versus time (𝑡 − T) for lycopene degradation during cooking methods - simple boiling and steaming. In the Fig. 4 , the continuous straight lines represent the theoretically fitted first order kinetic reaction with R 2 value 0.99, thereby confirming lycopene degradation kinetics to be a first order. It can be seen from Table 1 , that for the remaining three cooking methods lycopene degradation follows first order kinetics with R 2 value ranging from 0.91 to 0.99. The various fitted parameters for kinetic degradation of lycopene are given in Table 1 . It may be noted that the magnitude of the reaction rate constant for growth of lycopene concentration is larger (for example, the magnitude of \(\:{k}_{d}\) /𝑘 is about 5 times for boiling and 11 times for microwave cooking) than that for degradation of lycopene concentration, so degradation of lycopene concentration could be seen only after the growth of lycopene stops. The reaction rate constant \(\:{k}_{d}\) for degradation of lycopene varies significantly for different cooking methods except for close values for steaming and boiling. The value of \(\:{k}_{d}\) is highest for pan fry, followed by microwave, pressure cook, steaming and boiling. The significance of difference in reaction rate \(\:{k}_{d}\) may be seen by comparing the different value of Half- time \(\:{t}_{1/2}\) and Decimal Reduction Time (D-value) for lycopene degradation as given in Table 1 . The Half-life ( \(\:{t}_{1/2}\) ) is the time required for the initial concentration to reduce by 50% while Decimal Reduction Time (D-value) denotes the cooking time required for 90% destruction of the quality parameter, and were calculated using equation: $$\:{t}_{1/2}=-\frac{\text{ln}0.5}{{k}_{d}}$$ 3 and \(\:D=\frac{2.303}{{k}_{d}}\) (4) Earlier workers have also reported that degradation of lycopene obeyed first order kinetics. For example, it was reported that the degradation of lycopene follows the first order reaction model (Kaur et al. 2007) and thermal degradation of lycopene concentration follow first order kinetics (Bac et al. 2023). However, none of the reports mentioned on the growth kinetics of lycopene or made a comparison on various mechanism or processes during growth and decay of lycopene content. From Table 1 , we see that the half-life during boiling is about approximately 68 minutes while during frying is about 3 minutes. This means a large amount of maximum lycopene extracted has undergone degradation in a short time during frying and microwave cooking. The mechanism for degradation of lycopene concentration could be through oxidation or through isomerization as given in literature Hackett et al. (2006). In our experimental arrangement, the effect of oxidation and light on degradation of lycopene concentration is negligible as aluminium foil cover were used over each bowl containing the sample and our cooking method differs principally through heating rate and possible chemical effect (only in frying method). It was found in our experimental data that tomato cooked with boiling and steaming for 10 minutes relative to time T for maximum concentration (or 40 minutes from beginning) reduce lycopene concentration by 8% and 11% respectively while tomato cooked with frying and microwave for 5 minutes relative to time for maximum concentration reduce lycopene concentration by 68% and 46% respectively and tomato cooked in pressure cooker for 6 minutes lead to reduction of lycopene concentration by 31%. This demonstrates that degradation of lycopene concentration through isomerization mechanism could be mainly due to heat rate given (for different cooking methods) and some possible effect of chemical effect (during frying). In short, the degradation rate constant 𝑘𝑑 depend implicitly on heat rate (for different cooking methods) and chemical effect. 3.3. Degradation of Vitamin C In our present study, we observed that the concentration of Vitamin C does not grow during cooking but degrades from its initial value; this behavior is different from that of lycopene concentration. This suggests that Vitamin C concentration does not grow during cooking (and is not be related to breaking of tissue) but degrades. As our present interest is on the change in concentration during the cooking time, we seek to analyse the degradation kinetics of Vitamin C concentration during various cooking methods. The degradation of Vitamin C obeys first order chemical reaction kinetics and our result is in agreement as reported in literature (Demiray et al. 2013 ). From Table 1 , the first order reaction kinetics fitting on the degradation of Vitamin C have values of R2 ranging from 0.86 to 0.99. It can be seen (Table 1 ), that the reaction rate for Vitamin C degradation is highest for pan fry, followed by microwave, pressure cook, steaming and boiling. This behavior is similar to that of degradation of lycopene concentration and suggests that the reaction rate depends on rate of heat given (in various cooking method) and chemical action. 4. Conclusion The lycopene concentration first grows to a maximum value and then degrades during all the cooking methods. However, there is no such growth of Vitamin C concentration but only degrades in all the cooking methods. This suggests that the breaking of tomato tissue is related only with the release of lycopene but not with Vitamin C. It is found that the growth of lycopene concentration follows zeroth order kinetics while degradation of lycopene concentration obeys first order kinetics. There is no growth of Vitamin C in all the cooking methods but only the degradation of Vitamin C concentration is observed during cooking and follow a first order kinetic reaction. Our experimental result demonstrates the reaction rate for growth or degradation of both lycopene and Vitamin C depends on cooking methods and possibly on chemical effects. Declarations Acknowledgements : The authors would like to thank Dr Y. Sanatombi Devi, Department of Life Science, (Botany) Manipur University for identifying the species of Tomato. Funding: Not Applicable Conflict of interest : The authors declare that they have no competing interests. Ethics approval : Not Applicable. The research work and the report were made in an ethical and responsible manner. Consent to participate : Not Applicable. Consent for publication : Not Applicable. Availability of data and Material : The datasets used and analysed during the current study are available from the authors on reasonable request. The datasets generated and used in our present study are included in this article. Code Availability : Not Applicable Authors’ contributions : MAD conceived the idea of the research work and made experimental measurement. KNS helps in analysing the data and the interpretation of results and discussions. SG supervises the work. References Agarwal, A., Shen, H., Agarwal, S., & Rao, A. V. (2001). Lycopene content of tomato products: its stability, bioavailability and in vivo antioxidant properties. Journal of medicinal food , 4 (1), 9-15. Baç, H. S., Yemiş, O., & Özkan, M. (2023). Thermal stabilities of lycopene and β-carotene in tomato pulp and pink grapefruit juice. Journal of Food Engineering , 337 , 111217. Chang, C. H., Lin, H. Y., Chang, C. Y., & Liu, Y. C. (2006). Comparisons on the antioxidant properties of fresh, freeze-dried and hot-air-dried tomatoes. Journal of food engineering , 77 (3), 478-485. Ishiwu Charles, N., Iwouno, J. O., Obiegbuna James, E., & Ezike Tochukwu, C. (2014). Effect of thermal processing on lycopene, beta-carotene and Vitamin C content of tomato [Var. UC82B]. Journal of Food and Nutrition Sciences , 2 (3), 87-92. Chen, J., Shi, J., Xue, S. J., & Ma, Y. (2009). Comparison of lycopene stability in water-and oil-based food model systems under thermal-and light-irradiation treatments. LWT-Food Science and Technology , 42 (3), 740-747. Demiray, E., Tulek, Y., & Yilmaz, Y. (2013). Degradation kinetics of lycopene, β-carotene and ascorbic acid in tomatoes during hot air drying. LWT-Food Science and Technology , 50 (1), 172-176. Dewanto, V., Wu, X., Adom, K. K., & Liu, R. H. (2002). Thermal processing enhances the nutritional value of tomatoes by increasing total antioxidant activity. Journal of agricultural and food chemistry , 50 (10), 3010-3014. Fuhrman, B., Volkova, N., Rosenblat, M., & Aviram, M. (2000). Lycopene synergistically inhibits LDL oxidation in combination with vitamin E, glabridin, rosmarinic acid, carnosic acid, or garlic. Antioxidants and Redox Signaling , 2 (3), 491-506. Gómez-Prieto, M. S., Caja, M. M., Herraiz, M., & Santa-María, G. (2003). Supercritical fluid extraction of all-trans-lycopene from tomato. Journal of Agricultural and Food Chemistry , 51 (1), 3-7. Graziani, G., Pernice, R., Lanzuise, S., Vitaglione, P., Anese, M., & Fogliano, V. (2003). Effect of peeling and heating on carotenoid content and antioxidant activity of tomato and tomato-virgin olive oil systems. European Food Research and Technology , 216 , 116-121. Hackett, M. M., Lee, J. H., Francis, D., & Schwartz, S. J. (2004). Thermal stability and isomerization of lycopene in tomato oleoresins from different varieties. Journal of food science , 69 (7), 536-541. Hussein, L., & El-Tohamy, M. (1990). Vitamin A potency of carrot and spinach carotenes in human metabolic studies. International journal for vitamin and nutrition research. Internationale Zeitschrift fur Vitamin-und Ernahrungsforschung. Journal International De Vitaminologie Et De Nutrition , 60 (3), 229-235. Jayaraman, J. (1981). Laboratory manual in Biochemistry New Age International Publishers. New Delhi 180pp . Kaur, D., Sogi, D. S., & Abas Wani, A. (2006). Degradation kinetics of lycopene and visual color in tomato peel isolated from pomace. International Journal of Food Properties , 9 (4), 781-789. Lavelli, V., & Torresani, M. C. (2011). Modelling the stability of lycopene-rich by-products of tomato processing. Food Chemistry , 125 (2), 529-535. Franko, M., Bicanic, D. D., Luterotti, S., & Marković, K. (2014). Carotenes in processed tomato after thermal treatment. Marín, A., Ferreres, F., Tomás-Barberán, F. A., & Gil, M. I. (2004). Characterization and quantitation of antioxidant constituents of sweet pepper (Capsicum annuum L.). Journal of agricultural and food chemistry , 52 (12), 3861-3869. Valentas, K. J., Rotstein, E., & Singh, R. P. (1997). Handbook of food engineering practice . CRC press. Re, R., Bramley, P. M., & Rice-Evans, C. (2002). Effects of food processing on flavonoids and lycopene status in a Mediterranean tomato variety. Free Radical Research , 36 (7), 803-810. Rissanen, T., Voutilainen, S., Nyyssönen, K., & Salonen, J. T. (2002). Lycopene, atherosclerosis, and coronary heart disease. Experimental Biology and Medicine , 227 (10), 900-907. Sadasivam S, Manickam A (1992) Biochemical methods, second edition. New Age International Publisher, New Delhi Scita G (1992) Shi, J., Dai, Y., Kakuda, Y., Mittal, G., & Xue, S. J. (2008). Effect of heating and exposure to light on the stability of lycopene in tomato purée. Food control , 19 (5), 514-520. Clinton, S. K. (1998). Lycopene: chemistry, biology, and implications for human health and disease. Nutrition reviews , 56 (2), 35-51. Takeoka, G. R., Dao, L., Flessa, S., Gillespie, D. M., Jewell, W. T., Huebner, B., ... & Ebeler, S. E. (2001). Processing effects on lycopene content and antioxidant activity of tomatoes. Journal of Agricultural and Food Chemistry , 49 (8), 3713-3717. Yetenayet, B. T., & Hosahalli, S. R. (2015). Temperature and high-pressure stability of lycopene and vitamin C of watermelon Juice. African Journal of Food Science , 9 (5), 351-358. Van Boekel, M. A. (2008). Kinetic modeling of food quality: a critical review. Comprehensive reviews in food science and food safety , 7 (1), 144-158. Zechmeister, L., LeRosen, A. L., Schroeder, W. A., Polgar, A., & Pauling, L. (1943). Spectral characteristics and configuration of some stereoisomeric carotenoids including prolycopene and pro-γ-carotene. Journal of the American Chemical Society , 65 (10), 1940-1951. Additional Declarations No competing interests reported. Cite Share Download PDF Status: Posted 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. 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13:43:20","extension":"html","order_by":16,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":94163,"visible":true,"origin":"","legend":"","description":"","filename":"earlyproof.html","url":"https://assets-eu.researchsquare.com/files/rs-8505192/v1/825ea9a08153ca3e3844d7a0.html"},{"id":99796325,"identity":"11925a09-621e-4d4f-bac0-ef82d979ad59","added_by":"auto","created_at":"2026-01-08 13:41:13","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":27570,"visible":true,"origin":"","legend":"\u003cp\u003eCurves for the growth of lycopene concentration with time for all the different cooking methods\u003c/p\u003e","description":"","filename":"Onlinefloatimage1.png","url":"https://assets-eu.researchsquare.com/files/rs-8505192/v1/c822c25ffa24689baaf6fde6.png"},{"id":99685746,"identity":"b0ddd115-eb93-4031-9cf3-bd144a3c178a","added_by":"auto","created_at":"2026-01-07 09:28:04","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":20733,"visible":true,"origin":"","legend":"\u003cp\u003eStraight lines show the fitted zeroth order kinetics for lycopene growth for simple boiling and steaming cooking methods\u003c/p\u003e","description":"","filename":"Onlinefloatimage2.png","url":"https://assets-eu.researchsquare.com/files/rs-8505192/v1/b8fc0d2570497d78a34ff12e.png"},{"id":99795594,"identity":"5ead47b5-dea0-4f66-b70a-8d83dc2c57ef","added_by":"auto","created_at":"2026-01-08 13:38:57","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":21354,"visible":true,"origin":"","legend":"\u003cp\u003eStraight lines show the fitted zeroth order kinetics for lycopene growth for microwave, pressure cook and Pan Fry cooking methods\u003c/p\u003e","description":"","filename":"Onlinefloatimage3.png","url":"https://assets-eu.researchsquare.com/files/rs-8505192/v1/435256062ad0f7e6cd22c929.png"},{"id":99685757,"identity":"5bd73cb8-9eac-4097-ac08-0b90e023c5cf","added_by":"auto","created_at":"2026-01-07 09:28:04","extension":"png","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":22269,"visible":true,"origin":"","legend":"\u003cp\u003ePlot of ln (𝐶/𝐶o) versus time (𝑡− T) for lycopene degradation during cooking methods - simple boiling and steaming (with straight lines showing the fitted first order kinetics)\u003c/p\u003e","description":"","filename":"Onlinefloatimage4.png","url":"https://assets-eu.researchsquare.com/files/rs-8505192/v1/7a634fb54b8d72c8f680d6b3.png"},{"id":99805001,"identity":"44f2717d-3efb-4c35-ae48-a95747ce582f","added_by":"auto","created_at":"2026-01-08 14:15:13","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":802479,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-8505192/v1/9585724d-c02b-4b7c-921e-fb85d6a1114b.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Kinetics of the Growth and the Degradation of Lycopene and Vitamin C in Tomato slurry","fulltext":[{"header":"Highlight of research work","content":"\u003cp\u003e\u0026middot;\u0026nbsp;Lycopene growth follows zeroth order during cooking.\u003c/p\u003e\n\u003cp\u003e\u0026middot;\u0026nbsp;Maximum lycopene extraction in all cooking methods is nearly same irrespective of\u003c/p\u003e\n\u003cp\u003e\u0026nbsp; \u0026nbsp;reaction rate values.\u003c/p\u003e\n\u003cp\u003e\u0026middot;\u0026nbsp;Reaction rate for Lycopene degradation is smaller than for growth so degradation is seen\u003c/p\u003e\n\u003cp\u003e\u0026nbsp; \u0026nbsp;after its growth stops.\u003c/p\u003e\n\u003cp\u003e\u0026middot;\u0026nbsp;Main mechanism for Lycopene degradation in all cooking methods is through\u003c/p\u003e\n\u003cp\u003e\u0026nbsp; \u0026nbsp;isomerization.\u003c/p\u003e\n\u003cp\u003e\u0026middot;\u0026nbsp;Vitamin C is not related to breaking of tissue but only degrades following a first order\u003c/p\u003e\n\u003cp\u003e\u0026nbsp; \u0026nbsp;kinetics.\u003c/p\u003e"},{"header":"1. Introduction","content":"\u003cp\u003eAntioxidants like lycopene and Vitamin C (Marin et al. 2004, Rissanen et al. \u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e2002\u003c/span\u003e) are\u003c/p\u003e \u003cp\u003efound naturally in tomato (Lycopersicon Esculentum Mill) and other vegetables. These natural antioxidants exist, generally, in combination and might act synergistically (Fuhrman et al. \u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e2000\u003c/span\u003e). The specific biological properties of lycopene have been attributed to its unique structural and chemical features (Clinton \u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e1998\u003c/span\u003e); and these properties may, further, be enhanced by the presence of other active antioxidants such as \u003cem\u003eβ\u003c/em\u003e-carotene, vitamin E, and vitamin C. Lycopene (C\u003csub\u003e40\u003c/sub\u003eH\u003csub\u003e56\u003c/sub\u003e) has a molecular weight of 536.85 g/mol. There are more than 72 lycopene isomers, with all-trans-lycopene being the most important (Zechmeister et al. \u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e1943\u003c/span\u003e). The food items containing lycopene are consumed directly as raw or through processed food items. The stability of nutrients during processing depends on the nature of the commodity as well as on the severity of the processing. There are many reports on the increase or decrease of the lycopene content during the various processing of the food. For instance, it was reported that there was reduction in lycopene concentration during thermal treatment (Luterotti et al. 2015) in commercial double concentrated tomato puree, while a contrary report was given by Dewanto et al. (\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e2002\u003c/span\u003e) in the lycopene extracted from fresh cooked tomato slurry. In another case, Takeoka et al. (\u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e2001\u003c/span\u003e) had reported that the processing of fresh tomatoes into paste caused the concentration of total lycopene to decrease by 9 to 28% while others (Graziani et al. \u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e2003\u003c/span\u003e; Re et al.2002) had given a contrasting report that heating or processing tomatoes at higher temperature facilitates the increase in concentration of lycopene. It is known that lycopene concentration is sensitive to heat, light, oxygen, and metal ions (Lavelli and Torresani \u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e2011\u003c/span\u003e; Scita 1992); and may undergo (trans\u0026ndash;cis) isomerization, structural rearrangements or/and chemical reactions like oxidation (G\u0026oacute;mez-Prieto et al. \u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e2003\u003c/span\u003e; Demiray et al. \u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e2013\u003c/span\u003e). For example, heat treatments favour trans \u0026ndash; cis isomeric conversion of lycopene while light irradiation induced cis-isomer degradation (Chen et al. \u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e2009\u003c/span\u003e; Shi et al. \u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e2008\u003c/span\u003e). In one report temperatures between 75\u0026ndash;100\u0026deg;C favoured enhancing lycopene isomerisation during storage (Hackett et al. \u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e2004\u003c/span\u003e); but Agarwal et al. (\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e2001\u003c/span\u003e) have given a contrasting report that the storage temperature has no significant effect on concentration of lycopene in commercially canned tomato juice. All such divergent reports could be due to combined effect of two or more factors affecting lycopene concentration or on the type of lycopene base food materials. The relative change (increase or decrease) in lycopene concentration may be different for different factors like temperature, pressure chemical effect, light, genetic factors etc.; for example, the destruction rate of lycopene has been reported to be faster during thermal processing than during other methods like high pressure processing (Tola, et al. 2015). Presence of certain constituents like - tocopherols, ascorbic acid, and phenolic compounds - in the tomatoes may help in stabilizing lycopene during food processing (Takeoka et al. \u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e2001\u003c/span\u003e). So, it is possible to find divergent reports when many unnoticed factors come into play during the various food processing techniques. Since chemical kinetics provide a means to understand the mechanisms and the extent of chemical reactions in foods during storage and processing (van Boekel \u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e2008\u003c/span\u003e), the main purpose of our present study is to understand the effect of cooking on the kinetics of both lycopene concentration and vitamin C concentration in tomato slurry. Also, we seek to\u003c/p\u003e \u003cp\u003eunderstand the mechanism for such changes/reactions and discuss the significance of the results. In all our cooking methods, the effect due to oxidation and light were kept negligible so that the observed results could be related mainly to difference in heating rate associated with the cooking methods. The chemical effect of oil acting synergistically to heating rate during frying provide experimental evidence for combined effect of two factors affecting the kinetics of both lycopene and vitamin C concentration.\u003c/p\u003e"},{"header":"2. Materials and Methods","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003e2.1. Collection of fruits and preparation of samples\u003c/h2\u003e \u003cp\u003eThe mature red and ripe tomatoes were collected from local area of north Sekmai, Imphal\u003c/p\u003e \u003cp\u003eWest, Manipur, India. The tomato samples were identified as Solanum Peruvianum L. (wild\u003c/p\u003e \u003cp\u003etomatoes) (with VERN.NAME \u0026amp; USES as Khamen Ashinba Macha) in the DEPARTMENT OF LIFE SCIENCES, (BOTANY) MANIPUR UNIVERSITY, Canchipur, Manipur. Ripe tomatoes of similar sizes were selected and then washed thoroughly with tap water followed by distilled water and finally dried. The tomatoes were then crushed in a warring blender in order to obtain a uniform mixture. The final homogenizes mixture (or samples) so obtained were used in following experimental steps.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec4\" class=\"Section2\"\u003e \u003ch2\u003e2.2 Determination of lycopene\u003c/h2\u003e \u003cp\u003eLycopene content was determined, following the method given by Sadasivam and Manikam\u003c/p\u003e \u003cp\u003e(1992). About 1g of homogenized sample was accurately weighed and was repeatedly extracted with acetone using a pestle and mortar until the residue become colourless. The extract was transferred in a separating funnel containing petroleum ether and then the sample was separated into two phases. Only the upper phase was collected and stored in amber coloured bottle. A small amount of sodium sulphate was added and absorbance was taken at 503 nm. The lycopene content was calculated using the formula:\u003c/p\u003e \u003cp\u003e\u0026#119871;\u0026#119910;\u0026#119888;\u0026#119900;\u0026#119901;\u0026#119890;\u0026#119899;\u0026#119890; (\u0026#119894;\u0026#119899; \u0026#119898;\u0026#119892;/100\u0026#119892;)\u0026thinsp;=\u0026thinsp;3.1206 \u0026times; \u0026#119874;\u0026#119863; \u0026#119900;\u0026#119891; \u0026#119904;\u0026#119886;\u0026#119898;\u0026#119901;\u0026#119897;\u0026#119890; \u0026times; \u0026#119907;\u0026#119900;\u0026#119897;. \u0026#119898;\u0026#119886;\u0026#119889;\u0026#119890; \u0026#119906;\u0026#119901; \u0026times;100 / \u0026#119908;\u0026#119905;. \u0026#119900;\u0026#119891; \u0026#119904;\u0026#119886;\u0026#119898;\u0026#119901;\u0026#119897;\u0026#119890; \u0026times; 1000\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec5\" class=\"Section2\"\u003e \u003ch2\u003e2.3. Determination of Vitamin C\u003c/h2\u003e \u003cp\u003eVitamin C content was determined using the method given by Jayaraman (1985). In brief, weighed portion of the intact sample was extracted with sufficient volume of 5% metaphosphoric acid and 10% acetic acid solution. Then the extract was treated with activated charcoal. Next, 10% thiourea solution and 2,4 dinitrophenyl hydrazine reagents were added to the filtrate and water bathed for 3hrs and finally, it was cooled in ice water and 2ml of H2SO4 (85%) added dropwise. The colour of standard ascorbic acid was developed in a similar way. The results were read at 540nm.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec6\" class=\"Section2\"\u003e \u003ch2\u003e2.4. Chemical Reagents\u003c/h2\u003e \u003cp\u003eAll the chemicals and reagents used in the study were of analytical grade.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec7\" class=\"Section2\"\u003e \u003ch2\u003e2.5. Statistical Analysis\u003c/h2\u003e \u003cp\u003eANOVA analysis was employed to all the data obtained from the triplicate determination\u003c/p\u003e \u003cp\u003eusing Origin pro-8.5. The means that differed significantly were separated using Tukey\u0026rsquo;s Test.\u003c/p\u003e \u003c/div\u003e"},{"header":"3. Results and Discussion","content":"\u003cdiv id=\"Sec9\" class=\"Section2\"\u003e \u003ch2\u003e3.1. Growth of lycopene\u003c/h2\u003e \u003cp\u003eIn all the cooking methods, the lycopene content continues to increase till a maximum value and then the lycopene content decreases. It is observed that the value of maximum lycopene concentration for all the cooking methods was in a close range 9.22\u0026ndash;11.35 mg/100g (except frying, which has a maximum value 17.18 mg/100g); however, the time taken (say T) for reaching the maximum concentration is different for all the cooking methods. The reason would be addressed in latter part of this section. The increase in lycopene concentration during cooking has also been reported in literature (Ishiwu et al. 2014). Figure\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e show the curves for the growth of lycopene concentration with time for all the different cooking methods. It may be noted that the kinetic analysis of the growth of lycopene concentration was not done by earlier workers to the best of our knowledge. In our present study, we have used the software origin 9.0 for analysis and fitting of the experimental data. The growth of lycopene concentration in all the cooking methods were found to follow zero order kinetics:\u003cdiv id=\"Equ1\" class=\"Equation\"\u003e\u003cdiv format=\"TEX\" class=\"mathdisplay\" id=\"FileID_Equ1\" name=\"EquationSource\"\u003e\n$$\\:\\frac{C}{{C}_{o}}=kt$$\u003c/div\u003e\u003cdiv class=\"EquationNumber\"\u003e1\u003c/div\u003e\u003c/div\u003e\u003c/p\u003e \u003cp\u003ewhere \u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\:C\\)\u003c/span\u003e\u003c/span\u003e is the concentration of lycopene at time \u0026#119905; and \u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\:{C}_{o}\\)\u003c/span\u003e\u003c/span\u003e is the concentration of lycopene at initial time and \u0026#119896; is reaction rate constant. In Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e, the straight lines show the fitted zeroth order kinetics for lycopene growth for cooking methods - simple boiling and steaming, with values of R\u003csup\u003e2\u003c/sup\u003e 0.99285 and 0.91550 respectively. Similarly, the straight lines in Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e show the fitted zeroth order kinetics for lycopene growth for cooking methods - microwave, pressure cook and Pan Fry with values of R\u003csup\u003e2\u003c/sup\u003e 0.99428, 0.94589 and 0.99851 respectively. The growth of lycopene content during cooking is definitely related to the breaking of the tissue and its release; had the breaking of the tissue be complete the maximum value of lycopene concentration in all the cooking methods would be almost same. Literature reports that cooking or shredding led to physical destruction or softening of the plant cell membranes and breakdown the lycopene-protein complexes (Hussein and el-Tohamy \u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e1990\u003c/span\u003e), supports the reasoning given here. Chang et al. (\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e2006\u003c/span\u003e) had also made the suggestion that thermal processes broke down cell walls and weakened the bonding forces between lycopene and the tissue matrix, thereby enhancing the release of phytochemicals from the matrix. In our study, the reaction rate constant for growth of lycopene concentration are different for all the cooking methods (Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e); this suggest that the rate of breaking the tissue matrix and the release of lycopene is different for different cooking methods. The near values of maximum lycopene concentration in all the cooking methods suggest that the breaking of tomato matrix (due to applied heat) in all cooking methods (except frying) are of same degree, but for frying the breaking of the tissue and release of lycopene is highest. However, the time taken T for reaching maximum lycopene growth are different for all the cooking methods employed; this difference in values of T must be attributed mainly to the different values of growth reaction rate \u0026#119896;. The breaking of tissue matrix due to heat alone may not be complete, but in frying the chemical effect of oil further add up and scale up the breaking of tissue matrix and hence more lycopene is released. From Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e, one may note that the reaction rate constant for the lycopene growth is greatest for pan fry, followed by microwave, pressure cook, boiling and then steaming. The different reaction rate (\u0026#119896;) values for growth of lycopene for different cooking methods suggest its implicit dependence on rate of heat given and additive chemical effect of oil. Thus, we see that microwave cooking method is most effective cooking method for maximum extraction of lycopene if only heat factor is considered.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab1\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eReaction rate constants and other kinetic parameters for growth (zeroth order kinetics) of lycopene and degradation of lycopene (first order kinetics) and vitamin C (first order kinetics) in tomatoes during different cooking methods\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"11\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c8\" colnum=\"8\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c9\" colnum=\"9\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c10\" colnum=\"10\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c11\" colnum=\"11\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eCooking method\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e \u003cp\u003eGrowth of lycopene concentration\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"4\" nameend=\"c7\" namest=\"c4\"\u003e \u003cp\u003eDegradation of lycopene concentration\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"4\" nameend=\"c11\" namest=\"c8\"\u003e \u003cp\u003eDegradation of vitamin C concentration\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\:k\\)\u003c/span\u003e\u003c/span\u003e (per min)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eR\u003csup\u003e2\u003c/sup\u003e\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eD (in min)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003e\u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\:{t}_{1/2}\\)\u003c/span\u003e\u003c/span\u003e (in min)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003e\u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\:{k}_{d}\\)\u003c/span\u003e\u003c/span\u003e (per min)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c7\"\u003e \u003cp\u003eR\u003csup\u003e2\u003c/sup\u003e\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c8\"\u003e \u003cp\u003eD (in min)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c9\"\u003e \u003cp\u003e\u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\:{t}_{1/2}\\)\u003c/span\u003e\u003c/span\u003e(in min)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c10\"\u003e \u003cp\u003e\u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\:{k}_{d}\\)\u003c/span\u003e\u003c/span\u003e (per min)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c11\"\u003e \u003cp\u003eR\u003csup\u003e2\u003c/sup\u003e\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSimple boiling\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e0.0588\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.99285\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e225.6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e67.9\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e0.01021\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.99079\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e105.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e \u003cp\u003e31.6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c10\"\u003e \u003cp\u003e0.02195\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c11\"\u003e \u003cp\u003e0.97565\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSteaming\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e0.0393\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.91550\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e221.6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e66.7\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e0.01039\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.99269\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e110.2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e \u003cp\u003e33.2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c10\"\u003e \u003cp\u003e0.02089\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c11\"\u003e \u003cp\u003e0.98866\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePan Fry\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e3.251\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.99851\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e10.6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e3.2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e0.21754\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.96966\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e15.2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e \u003cp\u003e4.6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c10\"\u003e \u003cp\u003e0.15164\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c11\"\u003e \u003cp\u003e0.85367\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMicrowave\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e1.152\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.99428\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e22.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e6.6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e0.1049\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.92505\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e18.4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e \u003cp\u003e5.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c10\"\u003e \u003cp\u003e0.12535\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c11\"\u003e \u003cp\u003e0.88918\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePressure Cook\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e0.744\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.94589\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e36.6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e11.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e0.06281\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.98129\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e28.1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e \u003cp\u003e8.4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c10\"\u003e \u003cp\u003e0.08208\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c11\"\u003e \u003cp\u003e0.89971\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec10\" class=\"Section2\"\u003e \u003ch2\u003e3.2. Degradation of lycopene concentration\u003c/h2\u003e \u003cp\u003eIn all the cooking methods, the degradation of lycopene concentration can be seen after the lycopene concentration reached the maximum value. In the previous section, we have noted that the maximum lycopene concentrations for all the cooking methods were of near values and the time taken (T) for reaching the maximum concentration to be different. This difference in values of T was attributed mainly to the different values of growth reaction rate. As the lycopene concentration start decreasing from the maximum value, we shall take the initial lycopene concentration to be this maximum value and the analysis of lycopene degradation in latter part of cooking time would be carried out relative to T. In general, lycopene degradation follows first order kinetics. This may be shown in two ways \u0026ndash; either by plotting the lycopene concentration against time or by plotting log (lycopene concentration) against time. The curve for concentration as a function of time is an exponential curve for first order kinetics while the curve for log (concentration) versus time is a straight line, which is easy to visualise. In our present analysis, we choose the second method by considering the log (lycopene concentration) as a function of time. As we have mentioned before that lycopene degradation begin only after attaining maximum concentration, we therefore make the modification of counting time relative to T. We have use the software origin 9.0 for fitting (technique of least square fitting) the experimental data with the theoretical curve; interestingly, the degradation of lycopene concentration for all the cooking methods obeyed first order kinetic reactions. In our analysis, we have used the following equation for first order kinetics:\u003cdiv class=\"BlockQuote\"\u003e\u003cp\u003e \u003cspan class=\"InlineEquation\"\u003e \u003cspan class=\"mathinline\"\u003e\\(\\:\\text{ln}\\left(\\frac{C}{{C}_{o}}\\right)={k}_{d}\\left(t-T\\right)\\)\u003c/span\u003e \u003c/span\u003e (2),\u003c/p\u003e\u003c/div\u003e\u003c/p\u003e \u003cp\u003ewhere \u0026#119905; is time; \u0026#119862; is concentration at time \u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\:\\left(t-T\\right)\\)\u003c/span\u003e\u003c/span\u003e and \u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\:{C}_{o}\\)\u003c/span\u003e\u003c/span\u003e is initial lycopene concentration at time T. The reaction rate constant (\u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\:{k}_{d})\\)\u003c/span\u003e\u003c/span\u003e could be calculated using Eq.\u0026nbsp;(2). A theoretical treatment for the loss of food quality as a function of time in terms of reaction order may also be found elsewhere (Petros et al 1997). Figure\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003e depicts a representative plot of \u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\:\\text{ln}\\left(\\frac{C}{{C}_{o}}\\right)\\)\u003c/span\u003e\u003c/span\u003e versus time (\u0026#119905; \u0026minus; T) for lycopene degradation during cooking methods - simple boiling and steaming. In the Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003e, the continuous straight lines represent the theoretically fitted first order kinetic reaction with R\u003csup\u003e2\u003c/sup\u003e value 0.99, thereby confirming lycopene degradation kinetics to be a first order. It can be seen from Table \u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e, that for the remaining three cooking methods lycopene degradation follows first order kinetics with R\u003csup\u003e2\u003c/sup\u003e value ranging from 0.91 to 0.99. The various fitted parameters for kinetic degradation of lycopene are given in Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e. It may be noted that the magnitude of the reaction rate constant for growth of lycopene concentration is larger (for example, the magnitude of \u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\:{k}_{d}\\)\u003c/span\u003e\u003c/span\u003e/\u0026#119896; is about 5 times for boiling and 11 times for microwave cooking) than that for degradation of lycopene concentration, so degradation of lycopene concentration could be seen only after the growth of lycopene stops. The reaction rate constant \u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\:{k}_{d}\\)\u003c/span\u003e\u003c/span\u003e for degradation of lycopene varies significantly for different cooking methods except for close values for steaming and boiling. The value of \u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\:{k}_{d}\\)\u003c/span\u003e\u003c/span\u003e is highest for pan fry, followed by microwave, pressure cook, steaming and boiling. The significance of difference in reaction rate \u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\:{k}_{d}\\)\u003c/span\u003e\u003c/span\u003e may be seen by comparing the different value of Half- time \u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\:{t}_{1/2}\\)\u003c/span\u003e\u003c/span\u003e and Decimal Reduction Time (D-value) for lycopene degradation as given in Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e. The Half-life (\u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\:{t}_{1/2}\\)\u003c/span\u003e\u003c/span\u003e) is the time required for the initial concentration to reduce by 50% while Decimal Reduction Time (D-value) denotes the cooking time required for 90% destruction of the quality parameter, and were calculated using equation:\u003cdiv id=\"Equ2\" class=\"Equation\"\u003e\u003cdiv format=\"TEX\" class=\"mathdisplay\" id=\"FileID_Equ2\" name=\"EquationSource\"\u003e\n$$\\:{t}_{1/2}=-\\frac{\\text{ln}0.5}{{k}_{d}}$$\u003c/div\u003e\u003cdiv class=\"EquationNumber\"\u003e3\u003c/div\u003e\u003c/div\u003e\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"BlockQuote\"\u003e \u003cp\u003eand \u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\:D=\\frac{2.303}{{k}_{d}}\\)\u003c/span\u003e\u003c/span\u003e (4)\u003c/p\u003e \u003c/div\u003e \u003c/p\u003e \u003cp\u003eEarlier workers have also reported that degradation of lycopene obeyed first order kinetics. For example, it was reported that the degradation of lycopene follows the first order reaction model (Kaur et al. 2007) and thermal degradation of lycopene concentration follow first order kinetics (Bac et al. 2023). However, none of the reports mentioned on the growth kinetics of lycopene or made a comparison on various mechanism or processes during growth and decay of lycopene content.\u003c/p\u003e \u003cp\u003eFrom Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e, we see that the half-life during boiling is about approximately 68 minutes while\u003c/p\u003e \u003cp\u003eduring frying is about 3 minutes. This means a large amount of maximum lycopene extracted has undergone degradation in a short time during frying and microwave cooking. The mechanism for degradation of lycopene concentration could be through oxidation or through isomerization as given in literature Hackett et al. (2006). In our experimental arrangement, the effect of oxidation and light on degradation of lycopene concentration is negligible as aluminium foil cover were used over each bowl containing the sample and our cooking method differs principally through heating rate and possible chemical effect (only in frying method). It was found in our experimental data that tomato cooked with boiling and steaming for 10 minutes relative to time T for maximum concentration (or 40 minutes from beginning) reduce lycopene concentration by 8% and 11% respectively while tomato cooked with frying and microwave for 5 minutes relative to time for maximum concentration reduce lycopene concentration by 68% and 46% respectively and tomato cooked in pressure cooker for 6 minutes lead to reduction of lycopene concentration by 31%. This demonstrates that degradation of lycopene concentration through isomerization mechanism could be mainly due to heat rate given (for different cooking methods) and some possible effect of chemical effect\u003c/p\u003e \u003cp\u003e(during frying). In short, the degradation rate constant \u0026#119896;\u0026#119889; depend implicitly on heat rate (for different cooking methods) and chemical effect.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec11\" class=\"Section2\"\u003e \u003ch2\u003e3.3. Degradation of Vitamin C\u003c/h2\u003e \u003cp\u003eIn our present study, we observed that the concentration of Vitamin C does not grow during cooking but degrades from its initial value; this behavior is different from that of lycopene concentration. This suggests that Vitamin C concentration does not grow during cooking (and is not be related to breaking of tissue) but degrades. As our present interest is on the change in concentration during the cooking time, we seek to analyse the degradation kinetics of Vitamin C concentration during various cooking methods. The degradation of Vitamin C obeys first order chemical reaction kinetics and our result is in agreement as reported in literature (Demiray et al. \u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e2013\u003c/span\u003e). From Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e, the first order reaction kinetics fitting on the degradation of Vitamin C have values of R2 ranging from 0.86 to 0.99. It can be seen (Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e), that the reaction rate for Vitamin C degradation is highest for pan fry, followed by microwave, pressure cook, steaming and boiling. This behavior is similar to that of degradation of lycopene concentration and suggests that the reaction rate depends on rate of heat given (in various cooking method) and chemical action.\u003c/p\u003e \u003c/div\u003e"},{"header":"4. Conclusion","content":"\u003cp\u003eThe lycopene concentration first grows to a maximum value and then degrades during all the cooking methods. However, there is no such growth of Vitamin C concentration but only degrades in all the cooking methods. This suggests that the breaking of tomato tissue is related only with the release of lycopene but not with Vitamin C. It is found that the growth of lycopene concentration follows zeroth order kinetics while degradation of lycopene concentration obeys first order kinetics. There is no growth of Vitamin C in all the cooking methods but only the degradation of Vitamin C concentration is observed during cooking and follow a first order kinetic reaction. Our experimental result demonstrates the reaction rate for growth or degradation of both lycopene and Vitamin C depends on cooking methods and possibly on chemical effects.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eAcknowledgements\u003c/strong\u003e: The authors would like to thank Dr Y. Sanatombi Devi, Department of Life Science, (Botany) Manipur University for identifying the species of Tomato.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding:\u003c/strong\u003e Not Applicable\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConflict of interest\u003c/strong\u003e: The authors declare that they have no competing interests.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eEthics approval\u003c/strong\u003e: Not Applicable. The research work and the report were made in an ethical and responsible manner.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent to participate\u003c/strong\u003e: Not Applicable.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent for publication\u003c/strong\u003e: Not Applicable.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAvailability of data and Material\u003c/strong\u003e: The datasets used and analysed during the current study are available from the authors on reasonable request. The datasets generated and used in our present study are included in this article.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCode Availability\u003c/strong\u003e: Not Applicable\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthors’ contributions\u003c/strong\u003e: MAD conceived the idea of the research work and made experimental measurement. KNS helps in analysing the data and the interpretation of results and discussions. SG supervises the work.\u003c/p\u003e"},{"header":"References","content":"\u003cp\u003eAgarwal, A., Shen, H., Agarwal, S., \u0026amp; Rao, A. V. (2001). Lycopene content of tomato products: its stability, bioavailability and in vivo antioxidant properties. \u003cem\u003eJournal of medicinal food\u003c/em\u003e, \u003cem\u003e4\u003c/em\u003e(1), 9-15.\u003c/p\u003e\n\u003cp\u003eBaç, H. S., Yemiş, O., \u0026amp; Özkan, M. (2023). Thermal stabilities of lycopene and β-carotene in tomato pulp and pink grapefruit juice. \u003cem\u003eJournal of Food Engineering\u003c/em\u003e, \u003cem\u003e337\u003c/em\u003e, 111217.\u003c/p\u003e\n\u003cp\u003eChang, C. H., Lin, H. Y., Chang, C. Y., \u0026amp; Liu, Y. C. (2006). Comparisons on the antioxidant properties of fresh, freeze-dried and hot-air-dried tomatoes. \u003cem\u003eJournal of food engineering\u003c/em\u003e, \u003cem\u003e77\u003c/em\u003e(3), 478-485.\u003c/p\u003e\n\u003cp\u003eIshiwu Charles, N., Iwouno, J. O., Obiegbuna James, E., \u0026amp; Ezike Tochukwu, C. (2014). Effect of thermal processing on lycopene, beta-carotene and Vitamin C content of tomato [Var. UC82B]. \u003cem\u003eJournal of Food and Nutrition Sciences\u003c/em\u003e, \u003cem\u003e2\u003c/em\u003e(3), 87-92.\u003c/p\u003e\n\u003cp\u003eChen, J., Shi, J., Xue, S. J., \u0026amp; Ma, Y. (2009). Comparison of lycopene stability in water-and oil-based food model systems under thermal-and light-irradiation treatments. \u003cem\u003eLWT-Food Science and Technology\u003c/em\u003e, \u003cem\u003e42\u003c/em\u003e(3), 740-747.\u003c/p\u003e\n\u003cp\u003eDemiray, E., Tulek, Y., \u0026amp; Yilmaz, Y. (2013). Degradation kinetics of lycopene, β-carotene and ascorbic acid in tomatoes during hot air drying. \u003cem\u003eLWT-Food Science and Technology\u003c/em\u003e, \u003cem\u003e50\u003c/em\u003e(1), 172-176.\u003c/p\u003e\n\u003cp\u003eDewanto, V., Wu, X., Adom, K. K., \u0026amp; Liu, R. H. (2002). Thermal processing enhances the nutritional value of tomatoes by increasing total antioxidant activity. \u003cem\u003eJournal of agricultural and food chemistry\u003c/em\u003e, \u003cem\u003e50\u003c/em\u003e(10), 3010-3014.\u003c/p\u003e\n\u003cp\u003eFuhrman, B., Volkova, N., Rosenblat, M., \u0026amp; Aviram, M. (2000). Lycopene synergistically inhibits LDL oxidation in combination with vitamin E, glabridin, rosmarinic acid, carnosic acid, or garlic. \u003cem\u003eAntioxidants and Redox Signaling\u003c/em\u003e, \u003cem\u003e2\u003c/em\u003e(3), 491-506.\u003c/p\u003e\n\u003cp\u003eGómez-Prieto, M. S., Caja, M. M., Herraiz, M., \u0026amp; Santa-María, G. (2003). Supercritical fluid extraction of all-trans-lycopene from tomato. \u003cem\u003eJournal of Agricultural and Food Chemistry\u003c/em\u003e, \u003cem\u003e51\u003c/em\u003e(1), 3-7.\u003c/p\u003e\n\u003cp\u003eGraziani, G., Pernice, R., Lanzuise, S., Vitaglione, P., Anese, M., \u0026amp; Fogliano, V. (2003). Effect of peeling and heating on carotenoid content and antioxidant activity of tomato and tomato-virgin olive oil systems. \u003cem\u003eEuropean Food Research and Technology\u003c/em\u003e, \u003cem\u003e216\u003c/em\u003e, 116-121.\u003c/p\u003e\n\u003cp\u003eHackett, M. M., Lee, J. H., Francis, D., \u0026amp; Schwartz, S. J. (2004). Thermal stability and isomerization of lycopene in tomato oleoresins from different varieties. \u003cem\u003eJournal of food science\u003c/em\u003e, \u003cem\u003e69\u003c/em\u003e(7), 536-541.\u003c/p\u003e\n\u003cp\u003eHussein, L., \u0026amp; El-Tohamy, M. (1990). Vitamin A potency of carrot and spinach carotenes in human metabolic studies. \u003cem\u003eInternational journal for vitamin and nutrition research. Internationale Zeitschrift fur Vitamin-und Ernahrungsforschung. Journal International De Vitaminologie Et De Nutrition\u003c/em\u003e, \u003cem\u003e60\u003c/em\u003e(3), 229-235.\u003c/p\u003e\n\u003cp\u003eJayaraman, J. (1981). Laboratory manual in Biochemistry New Age International Publishers. \u003cem\u003eNew Delhi 180pp\u003c/em\u003e.\u003c/p\u003e\n\u003cp\u003eKaur, D., Sogi, D. S., \u0026amp; Abas Wani, A. (2006). Degradation kinetics of lycopene and visual color in tomato peel isolated from pomace. \u003cem\u003eInternational Journal of Food Properties\u003c/em\u003e, \u003cem\u003e9\u003c/em\u003e(4), 781-789.\u003c/p\u003e\n\u003cp\u003eLavelli, V., \u0026amp; Torresani, M. C. (2011). Modelling the stability of lycopene-rich by-products of tomato processing. \u003cem\u003eFood Chemistry\u003c/em\u003e, \u003cem\u003e125\u003c/em\u003e(2), 529-535.\u003c/p\u003e\n\u003cp\u003eFranko, M., Bicanic, D. D., Luterotti, S., \u0026amp; Marković, K. (2014). Carotenes in processed tomato after thermal treatment.\u003c/p\u003e\n\u003cp\u003eMarín, A., Ferreres, F., Tomás-Barberán, F. A., \u0026amp; Gil, M. I. (2004). Characterization and quantitation of antioxidant constituents of sweet pepper (Capsicum annuum L.). \u003cem\u003eJournal of agricultural and food chemistry\u003c/em\u003e, \u003cem\u003e52\u003c/em\u003e(12), 3861-3869.\u003c/p\u003e\n\u003cp\u003eValentas, K. J., Rotstein, E., \u0026amp; Singh, R. P. (1997). \u003cem\u003eHandbook of food engineering practice\u003c/em\u003e. CRC press.\u003c/p\u003e\n\u003cp\u003eRe, R., Bramley, P. M., \u0026amp; Rice-Evans, C. (2002). Effects of food processing on flavonoids and lycopene status in a Mediterranean tomato variety. \u003cem\u003eFree Radical Research\u003c/em\u003e, \u003cem\u003e36\u003c/em\u003e(7), 803-810.\u003c/p\u003e\n\u003cp\u003eRissanen, T., Voutilainen, S., Nyyssönen, K., \u0026amp; Salonen, J. T. (2002). Lycopene, atherosclerosis, and coronary heart disease. \u003cem\u003eExperimental Biology and Medicine\u003c/em\u003e, \u003cem\u003e227\u003c/em\u003e(10), 900-907.\u003c/p\u003e\n\u003cp\u003eSadasivam S, Manickam A (1992) Biochemical methods, second edition. New Age International Publisher, New Delhi Scita G (1992)\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eShi, J., Dai, Y., Kakuda, Y., Mittal, G., \u0026amp; Xue, S. J. (2008). Effect of heating and exposure to light on the stability of lycopene in tomato purée. \u003cem\u003eFood control\u003c/em\u003e, \u003cem\u003e19\u003c/em\u003e(5), 514-520.\u003c/p\u003e\n\u003cp\u003eClinton, S. K. (1998). Lycopene: chemistry, biology, and implications for human health and disease. \u003cem\u003eNutrition reviews\u003c/em\u003e, \u003cem\u003e56\u003c/em\u003e(2), 35-51.\u003c/p\u003e\n\u003cp\u003eTakeoka, G. R., Dao, L., Flessa, S., Gillespie, D. M., Jewell, W. T., Huebner, B., ... \u0026amp; Ebeler, S. E. (2001). Processing effects on lycopene content and antioxidant activity of tomatoes. \u003cem\u003eJournal of Agricultural and Food Chemistry\u003c/em\u003e, \u003cem\u003e49\u003c/em\u003e(8), 3713-3717.\u003c/p\u003e\n\u003cp\u003eYetenayet, B. T., \u0026amp; Hosahalli, S. R. (2015). Temperature and high-pressure stability of lycopene and vitamin C of watermelon Juice. \u003cem\u003eAfrican Journal of Food Science\u003c/em\u003e, \u003cem\u003e9\u003c/em\u003e(5), 351-358.\u003c/p\u003e\n\u003cp\u003eVan Boekel, M. A. (2008). Kinetic modeling of food quality: a critical review. \u003cem\u003eComprehensive reviews in food science and food safety\u003c/em\u003e, \u003cem\u003e7\u003c/em\u003e(1), 144-158.\u003c/p\u003e\n\u003cp\u003eZechmeister, L., LeRosen, A. L., Schroeder, W. A., Polgar, A., \u0026amp; Pauling, L. (1943). Spectral characteristics and configuration of some stereoisomeric carotenoids including prolycopene and pro-γ-carotene. \u003cem\u003eJournal of the American Chemical Society\u003c/em\u003e, \u003cem\u003e65\u003c/em\u003e(10), 1940-1951.\u003c/p\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":true,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"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":"Tomato, Cooking, Lycopene, Vitamin C, Kinetics order","lastPublishedDoi":"10.21203/rs.3.rs-8505192/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-8505192/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eThe present work focuses on the kinetics of both growth and degradation of lycopene and\u003c/p\u003e\n\u003cp\u003eVitamin C in tomato (\u003cem\u003eSolanum Peruvianum L)\u003c/em\u003e during the various cooking methods - Simple\u003c/p\u003e\n\u003cp\u003eboiling, steaming, frying, microwave and pressure cooking. In our study, the effect of oxidation and light were negligible by covering the bowl containing tomato slurry with aluminium foil and the samples in triplicate were pulled out after every fixed interval of time set different for all cooking methods. The growth and degradation of lycopene concentration were found to obey zeroth order and first order kinetics while the degradation of Vitamic C obeys first order kinetics. The maximum lycopene extraction in all cooking methods is nearly same irrespective of different growth reaction rate values. The reaction rate constant (during growth) is larger than that for lycopene degradation, so lycopene degradation is seen after growth of lycopene stops. Degradation of lycopene is mainly through isomerization. Chemical effect of oil acts synergistically to heating effect during frying. It is found that Vitamin C is not associated with breaking of tomato tissue but only degrades in all cooking methods following first order kinetics.\u003c/p\u003e","manuscriptTitle":"Kinetics of the Growth and the Degradation of Lycopene and Vitamin C in Tomato slurry","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2026-01-07 09:27:59","doi":"10.21203/rs.3.rs-8505192/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":"ed42a30f-683c-4e33-a610-70eb44cb25ea","owner":[],"postedDate":"January 7th, 2026","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2026-01-07T09:28:02+00:00","versionOfRecord":[],"versionCreatedAt":"2026-01-07 09:27:59","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-8505192","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-8505192","identity":"rs-8505192","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}