Evaluation of trace element contents in canned tomato paste and canned pineapple marketed in Algeria

Evaluation of trace element contents in canned tomato paste and canned pineapple marketed in Algeria | 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 Evaluation of trace element contents in canned tomato paste and canned pineapple marketed in Algeria Chahinez BELABID, Sabrina LANASRI, Nassim AYAD, Moussa MOKHTARI, and 1 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-7762159/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 This study aimed to assess the migration of metallic trace elements (MTEs) from metallic food packaging to canned foods. Iron, zinc, copper, cadmium, and lead were determined in 52 canned foods samples (tomato paste and pineapple) marketed in Algiers. The determination was carried out by AAS after mineralization by wet acid digestion. The results highlighted that approximately 29% of the analyzed samples did not meet the regulatory limits, especially for Cd, with 11 samples (21%) exhibiting high levels (≥ 0.05 mg/Kg). Conversely, statistical results indicated that concentrations of Fe, Zn, Cu, and Pb were statistically below regulatory limits. The study identified a significant increase in Zn and Cu contents with decreasing pH. Fe content was positively correlated with the presence of oxygen in the headspace. Zn and Cd contents were positively correlated, and both were positively correlated with food/packaging contact time. Metallic trace elements SAA Migration Tin can Canned foods Introduction Nowadays, packaging is extensively utilized across a diverse array of products. The field of food packaging is constantly evolving to meet specific needs and challenges. Metallic food packaging is widely considered as one of the most effective forms of food packaging materials. Tin can, known for its robustness and excellent barrier properties, minimizes headspace oxygen and allows food sterilization within hermetically sealed can ( Makki & Ziarati, 2014 ) . This ensures a prolonged, safe, ambient shelf life with minimal or no need for preservatives ( Makki & Ziarati, 2014 ) . Furthermore, tin cans exhibit durability against the rigors of storage and transportation, finding use in various food and beverage categories such as vegetables, fruits, meat, dairy products, soft drinks, teas, and more ( Geueke, 2016 ) . According to the (Regulation (EC) No 1935/2004) , any material or article intended to come into contact directly or indirectly with food must be sufficiently inert to preclude substances from being transferred to food in quantities large enough to endanger human health or to bring about an unacceptable change in the composition of the food or a deterioration in its organoleptic properties. During the last years, canned foods have garnered heightened attention in terms of food safety due to the risk of heavy metal contamination. This contamination arises from the migration of the MTEs from the metallic packaging materials to canned food, this process is strongly influenced by the interactions between food components and packaging material ( Arvanitoyannis & Bosnea, 2004 ) . Several factors impact corrosion rates, including thermal treatment, impurities in tinplate, nature of the organic coating, food characteristics (pH, additives, oxidizing agents), oxygen presence in the headspace, and storage conditions (time and temperature) (Noureddine El Moussawi et al., 2020 ). The French Food Safety Agency recognizes metallic food packaging as a potential source of MTEs ( AFSSA, 2010 ) . Their presence in high levels may affect the organoleptic characteristics of canned foods and expose humans to worrying levels of contamination ( Kassouf et al., 2013 ). Fe, Zn, Cu, Pb, and Cd represent five potential migrants from metallic packaging and are among the most widely studied in canned foods ( Kassouf et al., 2013 ; Makki & Ziarati, 2014 ; Massadeh & Al-Massaedh, 2018) . Lead and cadmium possess the highest toxic potential, while other metals may also pose a hazard to humans under specific conditions ( Kassouf et al., 2013 ). There is no recommended maximum level or legal limit for Fe, Zn, and Cu content in foods. However, according to the practical guide published in 2013 by the Committee of Experts on Food and Pharmaceutical Packaging of the Council of Europe, specific migration limits “SML” for Fe, Zn, and Cu in canned foods have been set (40 mg/Kg, 5 mg/Kg, and 4 mg/Kg, respectively) (Committee of Experts on Packaging Materials for Food and Pharmaceutical Products, 2013 ). These limits are based on data provided by industry in European Union member states, indicating that these SMLs are reasonably achievable at present ( Committee of Experts on Packaging Materials for Food and Pharmaceutical Products, 2013 ) . However, they should be subject to revision to account for advancements in scientific and technical knowledge and improvements in good manufacturing practices ( Committee of Experts on Packaging Materials for Food and Pharmaceutical Products, 2013 ) . As the most toxic heavy metals, the Codex Alimentarius commission (FAO/WHO) has established maximum limits “ML” for Pb and Cd in canned foods, set at 1 mg/Kg and 0.05 mg/Kg, respectively (Codex STAN 193–1995) . Our study aimed to assess the levels of MTEs (Fe, Zn, Cu, Pb and Cd) in canned tomato paste and canned pineapple from various brands marketed in Algiers, and exploring their relationship with migration factors in tin cans (can condition, headspace, contact time, and pH). Materials and methods Sample Collection The study included a total of 52 samples, including 36 samples of canned tomato paste, and 16 samples of canned pineapple. The canned tomato paste samples originated from 12 distinct brands, with three different batches selected for each brand to encompass various manufacturing dates. For canned pineapples, samples were obtained from six brands, with three batches chosen for four brands and two batches for the remaining two brands. Samples were collected from three to six different stores in Algiers, northern Algeria, over a five-month period (June – October 2021). Reagents Analytical reagents-grade chemicals were employed for samples processing. Doubly distilled deionized water (18.2 MΩ/cm, resistivity) was used for standards, reagents, and samples preparation. Buffer solutions pH 4.00 and pH 7.00 (Sigma-Aldrich, Germany), nitric acid HNO 3 60% (HCPro Hygiene Chemicals Production, Algeria), hydrogen peroxide H 2 O 2 10% (PPSP, Algeria), and hydrochloric acid HCl > 37% (Fluka Chemika, Germany) were also used. Standard solutions for calibration were prepared by diluting a stock solution of 1000 mg/mL in 3% nitric acid of each tested element Fe, Zn, Cu, Pb, and Cd (Atomic Absorption Standard, Agilent Technologies USA). Apparatus AquaMax Ultra 370 Series water purification system (Younglin, South Korea) was utilized for distilled water purification. The analytical balance, Axis ALN 120G (Poland), with an accuracy of d = 0.1 mg, and the pH meter, HANNA instruments HI 2211 (Holland), with a precision of ± 0.01, were used. The BOSCH universal chopper (Germany) equipped with stainless steel cutters was used to grind pineapple slices. MTEs measurements were performed using Atomic Absorption Spectrometer (AAS) (Agilent technologies, USA). The 240 FS flame system (FAAS) with deuterium D 2 lamp for background correction was used to Fe, Zn, and Cu measurements. Meanwhile, the measurements of Pb and Cd were carried out by the 240 Z system for graphite furnace atomic absorption (GFAAS), equipped with Zeeman background correction. Analysis of Samples Can Corrosion The condition of the tin cans was visually inspected. We noted the presence or absence of corrosion on the “exterior” surface of the cans and recorded the intensity of corrosion (weak or strong). Contact Time The interaction time between canned food samples and the tin cans was expressed in days. Calculations involved determining the duration from the manufacturing date to the date of can opening. Headspace The headspace was measured as the (volume) between the product and the can lid. Using a caliper, the height of the headspace “h” was recorded in centimeters (cm). the volume “V” was calculated with the formula: \(\:{\varvec{V}\:\left({\varvec{c}\varvec{m}}^{3}\right)}_{\:}=\:{\left(\frac{\varvec{d}}{2}\right)}^{2}\:\times\:\:\varvec{\pi\:}\:\times\:\:\varvec{h}\:=\:{\varvec{r}}^{2}\:\times\:\:\varvec{\pi\:}\:\times\:\:\varvec{h}\:\) Where: d = diameter of cans (cm); h = height of the headspace (cm); r = radius of cans (cm). Measurement of pH Manual homogenization was done for canned tomato paste samples, and the pH was measured after dissolving 2.0 g ± 0.1 mg in ultrapure distilled water. Meanwhile, for canned pineapples, pH measurement was performed directly by immersing probes into the covering liquid. Samples Preparation and Acid Digestion Method In this study, the tested canned food samples were prepared following these steps: Each canned food sample was thoroughly homogenized. Decontaminated glass spatulas were used for the canned tomato paste samples, while the universal chopper with stainless steel cutter was employed for the canned pineapple samples. 1.0 g ± 0.1 mg of homogenized food sample placed in a decontaminated balloon glassware. Mineralization using a modified wet digestion method ( Demirel et al., 2008 ; Saracoglu et al., 2007 ) with a mixture of HNO 3 :H 2 O 2 (3:2). Twenty-five milliliters of the mixture were utilized for each 1.0 g sample, followed by the addition of 0.5 mL of HCl. The resulting mixtures were heated to 150°C for 2 ½ hours. Filtration into 50 mL volumetric flask after cooling, and dilution with deionized water. A blank solution was prepared following the same procedure. All collected samples and the blank test were stored in polypropylene tubes at room temperature until analysis. Quantitative Determination of the Trace Elements Calibration was conducted with five aqueous standards, including a blank. For Fe, Zn, and Cu calibration, we used solutions from 0.2 to 2.0 mg/L, while, for Pb, and Cd the solutions were from 20 to 100 µg/L. AAS analysis was carried out at the most analytical spectral lines of the metals: (Fe 248.3 nm, Zn 213.9 nm, and Cu 324.8 nm) by the FAAS using an air-acetylene flame, and (Cd 228.8 nm and Pb 283.3 nm) by GFAAS using argon as an inert gas. Data Analysis In this study, we performed descriptive analysis on all the dataset outcomes. Furthermore, we performed comparative univariate tests between the results of the two analyzed samples categories (canned tomato paste and canned pineapple), and between the obtained results and regulatory limit values. Subsequently, a correlation matrix was applied to the nine variables inherent from dataset: pH levels, headspaces, contact times, can corrosion, and the five MTEs under evaluation. All analysis were performed using R statistical software version 4.3.2. Results The can condition was coded as follows: 1 for cans in good condition (no corrosion), 2 if the cans exhibited slight corrosion, and 3 for heavy corrosion. The results obtained are summarized in Table 1 . Table 1 External states of cans checked for the two categories of samples. Sample Modality Frequency (%) Canned tomato paste 1 63.89 2 25.00 3 11.11 Canned pineapple 1 87.50 2 12.50 3 0.00 The average values of headspaces, food-packaging contact time, and pH values of the studied samples are provided in Table 2 . Table 2 Results obtained for the various factors studied influencing the migration of MTEs from cans to packaged food. Samples Min Max Mean SD (n-1) * Headspace (cm 3 ) Canned tomato paste 0.00 74.62 23.56 21.16 Canned pineapple 0.00 69.24 18.75 22.82 Contact time (days) Canned tomato paste 59.00 610.00 250.44 116.44 Canned pineapple 199.00 553.00 278.81 86.80 pH Canned tomato paste 4.19 4.63 4.41 0.09 Canned pineapple 3.39 3.86 3.64 0.14 * SD (n-1) Standard Deviation. The headspaces values for cans in the two studied food categories were compared and the results indicated no statistically significant difference (p = 0,46) ( Table 2 ) . Meanwhile, the pH values measured for canned tomato paste and canned pineapple revealed statistically significant difference (p < 0.0001) ( Table 2 ) . The maximum allowable pH level for canned tomato paste is 4.5 (Codex STAN 13-1981) . We compared the measured pH values for canned tomato paste samples with this threshold value, and the test indicated that the pH values obtained are statistically lower than the threshold value (p < 0.0001). Out of the 36 analyzed samples, only one showed a pH value exceeding the threshold (pH = 4.63 ± 0.01). For canned pineapple, there is no specific pH limit according to Codex standards (Codex STAN 42-1981) . However, pineapple pH values can range from 3.20 to 4.00 ( Downing, 1996 ) . All measured pH values for the canned pineapple samples fell within this interval, ranging from a minimum of (pH = 3.39 ± 0.01) to a maximum of (pH = 3.86 ± 0.01). The mean concentrations of the MTEs measured in the 52 samples are presented in Table 3 . Table 3 Concentrations of MTEs (mg/Kg) obtained in the two categories of samples. MTE Sample Min Max Mean SD (n-1) * Fe Canned tomato paste 1.30 48.35 18.15 10.92 Canned pineapple 0.18 6.38 2.12 1.96 Zn Canned tomato paste 0.38 5.42 2.53 1.36 Canned pineapple < LOQ 3.62 0.61 0.99 Cu Canned tomato paste < LOQ 23.00 2.36 4.13 Canned pineapple < LOQ 1.65 0.88 0.46 Cd Canned tomato paste < LOQ 2.45 0.14 0.43 Canned pineapple < LOQ 1.34 0.18 0.43 Pb Canned tomato paste < LOQ 0.12 0.003 0.02 Canned pineapple < LOQ < LOQ / / * SD (n-1) Standard Deviation. The concentrations of Fe, Zn, and Cu obtained in the canned tomato paste samples were statistically higher than those obtained in the canned pineapple samples, with p-values of (p < 0.0001), (p = 0.0319), and (p < 0.0001), respectively. However, the statistical tests revealed that there is no statistically significant difference between the analyzed canned tomato paste and canned pineapple regarding the concentration of Cd and Pb obtained (p = 0.5593 and p = 0.9804, respectively). Correlation matrix was performed on all the studied parameters. This was accomplished using Pearson correlation matrices, which are illustrated in Table [4–5] . For canned tomato paste, the correlation matrix ( Table 4 ) revealed that the Zn and Cu content were negatively correlated with the pH values, (r = − 0.46) and (r = − 0.45), respectively. Zn content and Cu content were positively correlated (r = 0.40). Fe content and contact time were also positively correlated (r = 0.31). For canned pineapple, the correlation matrix ( Table 5 ) reveals a positive correlation between Fe content and headspace (r = 0.60). Zn and Cd contents were positively correlated (r = 0.58), and both were positively correlated with food-packaging contact time, (r = 0.59) and (r = 0.53), respectively. Table 4 Correlation matrix coefficients between the MTEs assayed in the canned tomato paste samples and the four factors influencing migration. Variables Can condition Headspace Contact time pH Fe Cu Zn Cd Pb Can condition 1 Headspace 0.11 1 Contact time 0.19 -0.04 1 pH -0.27 0.03 -0.10 1 Fe 0 -0.20 0.31 0.14 1 Cu 0.29 0.02 0.13 -0.45 0.02 1 Zn 0.04 -0.01 0.07 -0.46 0.22 0.40 1 Cd 0.25 0.28 0.16 0.17 -0.03 -0.04 0.19 1 Pb 0.13 0.05 -0.24 0.10 -0.17 -0.01 -0.24 -0.05 1 Table 5 Correlation matrix coefficients between the MTEs assayed in the canned pineapple samples and the four factors influencing migration. Variables Can condition Headspace Contact time pH Fe Cu Zn Cd Can condition 1 Headspace -0.26 1 Contact time -0.01 -0.24 1 pH 0.39 -0.10 0.21 1 Fe -0.34 0.60 0.10 0.16 1 Cu 0.15 -0.09 -0.06 -0.07 -0.62 1 Zn 0.03 -0.03 0.59 0.07 -0.06 -0.11 1 Cd -0.16 -0.27 0.53 -0.11 -0.21 0.12 0.58 1 Discussion The results indicate that Fe was the most dominant MTE in canned tomato paste samples, with an average concentration of (18.15 ± 10.92 mg/Kg), followed by Zn (2.53 ± 1.36 mg/Kg), Cu (2.36 ± 4.13 mg/Kg), Cd (0.14 ± 0.43 mg/Kg), and finally Pb (0.003 ± 0.02 mg/Kg). These findings align with those reported by ( Safta et al., 2020 ), who analyzed canned tomato paste samples in Tunisia. Their study revealed Fe as the most abundant MTE with an average of (18.81 ± 2.71 mg/Kg), followed by Zn and Cu with averages of (3.61 ± 1.80 mg/Kg) and (1.51 ± 0.35 mg/Kg), respectively ( Safta et al., 2020 ). However, Cd levels were lower than our results at (0.05 ± 0.01 mg/Kg), and Pb was not detected in the canned tomato paste analyzed by ( Safta et al., 2020 ). In the canned pineapple samples, Fe emerged as the most abundant element, averaging (2.12 ± 1.96 mg/Kg), followed by Cu (0.88 ± 0.46 mg/Kg), Zn (0.61 ± 0.99 mg/Kg), Cd (0.18 ± 0.43 mg/Kg), while Pb was not detected (< LOQ). A study conducted by Massadeh et al., ( 2018 ) on canned pineapple samples in Jordan yielded non-comparable results, with Pb averaging (2.80 ± 0.35 mg/Kg), followed by Cu (0.91 ± 0.03 mg/Kg), Cd (0.56 ± 0.02 mg/Kg), and Zn (0.32 ± 0.26 mg/Kg). From the statistical results, the difference found between the Fe, Zn, and Cu contents in canned tomato paste and canned pineapple may be attributed to the acidic nature of canned tomato paste, coupled with the presence of added salt as a stabilizer, which can promote corrosion and elevate iron content ( Safta et al., 2020 ). The elevated level of Fe migration in canned tomato paste may also be attributed to the interaction of the metal surface with nitrates present in heavily fertilized soils ( Barone et al., 2015 ). This is due to the reduction of nitrate anions by various intermediates to ammonia, which serves as corrosion accelerators in tomato products ( Barone et al., 2015 ). Out of the 36 analyzed samples of canned tomato paste, two exhibited Fe migration values exceeding the threshold (40 mg of Fe/Kg), two other samples surpassed the SML of Zn (5 mg of Zn/Kg), and two samples had Cu content exceeding the migration threshold (4 mg of Cu/Kg). In contrast, eight out of the 36 samples of canned tomato paste exceeded the limit for cadmium (0.05 mg of Cd/Kg). However, all the analyzed samples of canned tomato paste showed levels below the regulatory limit for Pb (1 mg of Pb/Kg). The canned pineapple samples, in contrast, demonstrated concentrations below the regulatory limits for Fe, Zn, Cu, and Pb. Nevertheless, three samples out of the 16 analyzed samples exceeded the limit set by the Codex for Cd. However, we conducted statistical tests to compare the concentrations obtained with the regulatory limits. The concentrations of Fe, Zn, Cu, and Pb for both sample categories are statistically lower than the regulatory limits (p ≤ 0.01). The statistical tests were non-significant for the Cd concentrations in the two samples categories compared to ML. In this case, increasing the sample size is necessary to elucidate the significance of the measured contents for both sample categories. The correlation matrix ( Table 4 ) reveals a negative correlation between Zn and Cu content in canned tomato paste and the pH values. In the literature, the pH of canned foods has been identified as a factor influencing the corrosion of metal cans used in food packaging; lower pH levels tend to accelerate corrosion, directly impacting the migration of certain MTEs from the packaging materials to the packaged food product ( Robertson, 2016 ) . Buculei et al., 2014 , observed that can corrosion is favored when the pH values of canned food fall within the range of [3.50–4.00]. They further noted that the presence of certain organic acids, such as citric acid and malic acid, can enhance can corrosion ( Buculei et al., 2014 ). We also find a weak positive correlation between Zn content and Cu content in canned tomato paste. This observation can be explained by the fact that Cu acts as a depolarizer, accelerating the corrosion of steel by catalyzing the reduction of oxygen ( Robertson, 2016 ) . Cu can potentially enter foodstuffs through the application of copper-based pesticides commonly used on farms in certain countries ( Onianwa et al., 2001 ). For canned pineapple, the correlation matrix ( Table 5 ) reveals a positive correlation between Fe content and headspace. The headspace influences the corrosion of metal cans, which is why it is recommended to minimize it. This reduction aims to decrease the oxygen level in cans, thereby increasing the shelf life of packaged foods ( Perring & Basic-Dvorzak, 2002 ; Robertson, 2016 ) . Zn and Cd levels exhibit a positive correlation with food-packaging contact time. Experimental data indicate that the concentration of the migrating compound is directly proportional to the square root of contact time ( Arvanitoyannis & Kotsanopoulos, 2014 ) . Zn contents are also positively correlated with Cd contents, this correlation can be explained by the presence of Cd in Zn ores ( Committee of Experts on Packaging Materials for Food and Pharmaceutical Products, 2013 ) . It is crucial to note that the contamination of samples by Zn can be attributed to its use in the manufacturing of galvanized steel, where zinc functions as an anti-rust coating on Fe or other metals due to its strong reducing agent properties ( Committee of Experts on Packaging Materials for Food and Pharmaceutical Products, 2013 ) . Additionally, it should be emphasized that Zn is a component of fertilizers ( Committee of Experts on Packaging Materials for Food and Pharmaceutical Products, 2013 ) . Food contamination by Cd may be linked to its presence as an impurity in the alloys used for can manufacturing ( Safta et al., 2020 ). Another possible contributing factor is the prior contamination of fresh foods by phosphate fertilizers or sewage sludge used on some farmlands ( Committee of Experts on Packaging Materials for Food and Pharmaceutical Products, 2013 ) . No correlation was observed between the content of MTEs and the can condition. External corrosion is likely attributed to environmental factors such as food residues, the quality of process water or steam, corrosive glues or labels, as well as improper handling and storage conditions of the cans (temperature, humidity) ( Abdel-Rahman, 2015 ) . Conclusion The results indicated that around 29% of the analyzed samples did not meet the regulations concerning the presence of MTEs in canned foodstuffs. This includes cadmium, with 11 out of the 52 analyzed samples (21%) surpassing its ML (0.05 mg/Kg). Therefore, our study successfully identified the presence of some MTEs in canned tomato paste and canned pineapple, revealing correlation with certain factors (pH value, contact time, and headspace). This serves as a preliminary investigation that could be enhanced through a multicenter study conducted over an extended period, involving a larger sample size, and using more advanced analysis methods to validate and extend the findings. Declarations Data availability The data presented in this study are available on request from the corresponding author. Due to the confidential nature of the brand names analyzed, the raw data are not publicly available. Competing interests The authors do not have any conflict of interest. Funding The authors did not receive support from any organization for the submitted work. Authors’ contributions Conceptualization: C.B. and S.L.; Methodology: C.B., S.L. and M.M.; Data curation: C.B.; Formal analysis and investigation: N.A. and C.B.; Write – original draft preparation: C.B.; Write – review and editing: S.L. and N.A.; Supervision: O.H. all authors have read and agreed to the published version of the manuscript. Acknowledgements Reagents and materials used for this stady were provided and financed by Centre de Recherche Scientifique et Technique en Analyses Physico-Chimiques, Bou-Ismail, Tipaza, Algeria. We are grateful to Mr. Walid Rezgui for his technical assistance and expertise in performing the SAA analysis of the samples. Ethic statement The authors confirm that this study did not involve human participants or live animals . This research was conducted on inert materials , specifically food samples. The names of the brands analyzed have been kept anonymous to maintain objectivity and confidentiality . All methods were carried out in accordance with ethical guidelines for scientific analysis. References Abdel-Rahman NAG (2015) Tin-plate corrosion in canned foods. Journal of Global Biosciences 4(7):2966–2971. AFSSA (2010). Avis de l'Agence Française de Sécurité Sanitaire des Aliments relatif au projet de résolution du Conseil de l'Europe sur les métaux et alliages utilisés dans les matériaux et objets destinés au contact des denrées alimentaires. Saisine n°2010-Sa-0119. https://www.anses.fr/fr/system/files/MCDA2010sa0119.pdf. Arvanitoyannis IS, Bosnea L (2004) Migration of substances from food packaging materials to foods. Critical Reviews in Food Science and Nutrition 44(2):63–76. https://doi.org/10.1080/10408690490424621 Arvanitoyannis IS, Kotsanopoulos KV (2014) Migration phenomenon in food packaging. Food–package interactions, mechanisms, types of migrants, testing and relative legislation:A Review. Food and Bioprocess Technology 7(1):21–36. https://doi.org/10.1007/s11947-013-1106-8 Barone C, Bolzoni L, Caruso G, Montanari A, Parisi S, Steinka I (2015) Food packaging hygiene. Springer International Publishing, pp. 122–123. https://doi.org/10.1007/978-3-319-14827-4 Buculei A, Amariei S, Oroian M, Gutt G, Gaceu L, Birca A (2014) Metals migration between product and metallic package in canned meat. LWT - Food Science and Technology 58(2):364–374. https://doi.org/10.1016/j.lwt.2013.06.003 Committee of Experts on Packaging Materials for Food and Pharmaceutical Products (2013) Metals and alloys used in food contact materials and articles: A practical guide for manufacturers and regulators. European Directorate for the Quality of Medicines & HealthCare (EDQM). Demirel S, Tuzen M, Saracoglu S, Soylak M (2008) Evaluation of various digestion procedures for trace element contents of some food materials. Journal of Hazardous Materials 152(3):1020–1026. https://doi.org/10.1016/j.jhazmat.2007.07.077 Downing DL (1996) CHAPTER 2—Canning of Fruits. In D. L. Downing (Ed.), A Complete Course in Canning and Related Processes, Thirteenth Edition. Woodhead Publishing, pp. 129–192. https://doi.org/10.1533/9781845696214.129 EC (2004) Regulation No 1935/2004 of the European Parliament and of the Council of 27 October 2004 on materials and articles intended to come into contact with food and repealing Directives 80/590/EEC and 89/109/EEC. JO L 338, 13.11.2004, p. 4. FAO and WHO (1995) General standard for contaminants and toxins in food and feed. Codex Alimentarius commission (Codex STAN 193-1995). FAO and WHO (1981) Norme pour les ananas en conserve. Commission du Codex Alimentarius (Codex STAN 42-1981). FAO and WHO (1981) Standard for preserved tomatoes. Codex Alimentarius commission (Codex STAN 13-1981). Geueke B (2016) Dossier - Can coatings. Food Packaging Forum, 1-10. DOI: 10.5281/zenodo.200633. Kassouf A, Chebib H, Lebbos N, Ouaini R (2013) Migration of iron, lead, cadmium and tin from tinplate-coated cans into chickpeas. Food Additives & Contaminants: Part A 30(11):1987–1992. https://doi.org/10.1080/19440049.2013.832399 Makki FM, Ziarati P (2014) Determination of histamine and heavy metal concentrations in tomato pastes and fresh tomato ( Solanum lycopersicum ) in Iran. Biosciences Biotechnology Research Asia 11(2):537–544. https://doi.org/10.13005/bbra/1304 Massadeh AM, Al-Massaedh “Ayat Allah” T (2018) Determination of heavy metals in canned fruits and vegetables sold in Jordan market. Environmental Science and Pollution Research 25(2):1914–1920. https://doi.org/10.1007/s11356-017-0611-0 Noureddine El Moussawi S, Camel V, Cladière M, Lebbos N, Chébib H, Ouaini R (2020) Parameters influencing the migration of trace metals in uncoated fruit cans. Journal of Food Processing and Preservation 44(9): 1–12. https://doi.org/10.1111/jfpp.14653 Onianwa PC, Adeyemo AO, Idowu OE, Ogabiela EE (2001) Copper and zinc contents of Nigerian foods and estimates of the adult dietary intakes. Food Chemistry, 72(1):89–95. https://doi.org/10.1016/S0308-8146(00)00214-4 Perring L., Basic-Dvorzak M. (2002) Determination of total tin in canned food using inductively coupled plasma atomic emission spectroscopy. Analytical and Bioanalytical Chemistry, 374(2):235–243. https://doi.org/10.1007/s00216-002-1420-x Robertson GL (2016) Food Packaging Principles and Practice Third Edition, Taylor & Francis Group, pp. 214–219. https://doi.org/10.1201/b21347 Safta M., Limam I., Jebali R., Marzouki M., Driss MR., Kalfat R. (2020). Monitoring of metals migration and identification of corrosion sources in canned tomatoes and sardines. International Journal of Environmental Analytical Chemistry, 3:4664–4677. https://doi.org/10.1080/03067319.2020.1786550 Saracoglu S., Saygi K., Uluozlu O., Tuzen M., Soylak M. (2007). Determination of trace element contents of baby foods from Turkey. Food Chemistry, 105(1):280–285. https://doi.org/10.1016/j.foodchem.2006.11.022 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. 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-7762159","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":536431213,"identity":"51857f14-3f2b-47f4-8e20-f3620857339c","order_by":0,"name":"Chahinez BELABID","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA3klEQVRIiWNgGAWjYDACCQY2BoYChgQ2huQDIK4MkVoMQFrSEkBcHuK1MDDkGID4hLXwz25ge/DBwC6Pjz3n86sbNRY8DOyHj27Aa8mdA+yGMwySi9l43m6zzjkGdBhPWtoNfFoMJBLYpHkMmBPbJHK3GeewAbVI8JgR1vLHoB6oJeeZcc4/YrUwGBwGaWF+nNtGhBaJG4nthj0Gx4F+eWbGnNsnwcNGyC/8M5KPPfhRUZ0n3578+HPOtzo5fvbDx/BqYWBgbICx2CTAJH7lqID5AymqR8EoGAWjYOQAALiGQP4hkU3KAAAAAElFTkSuQmCC","orcid":"","institution":"Faculty of Pharmacy, The University of Health Sciences","correspondingAuthor":true,"prefix":"","firstName":"Chahinez","middleName":"","lastName":"BELABID","suffix":""},{"id":536431214,"identity":"493e7921-dd9e-478a-8f05-f5ac6676bd8b","order_by":1,"name":"Sabrina LANASRI","email":"","orcid":"","institution":"Faculty of Pharmacy, The University of Health Sciences","correspondingAuthor":false,"prefix":"","firstName":"Sabrina","middleName":"","lastName":"LANASRI","suffix":""},{"id":536431215,"identity":"a22a9361-67e4-4ba5-a9e5-062e104d9172","order_by":2,"name":"Nassim AYAD","email":"","orcid":"","institution":"Pasteur Institute of Algeria","correspondingAuthor":false,"prefix":"","firstName":"Nassim","middleName":"","lastName":"AYAD","suffix":""},{"id":536431216,"identity":"5bede62d-9ae8-487a-8bf5-349cc8fb85b3","order_by":3,"name":"Moussa MOKHTARI","email":"","orcid":"","institution":"Ecole Nationale Supérieure d’Agronomie","correspondingAuthor":false,"prefix":"","firstName":"Moussa","middleName":"","lastName":"MOKHTARI","suffix":""},{"id":536431217,"identity":"f9e001c7-fb80-40db-9253-f4ea8573305b","order_by":4,"name":"Ouahiba HADJOUDJ","email":"","orcid":"","institution":"Faculty of Pharmacy, The University of Health Sciences","correspondingAuthor":false,"prefix":"","firstName":"Ouahiba","middleName":"","lastName":"HADJOUDJ","suffix":""}],"badges":[],"createdAt":"2025-10-01 19:53:11","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-7762159/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-7762159/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":94750496,"identity":"2bdbe4c5-c7c5-486b-8961-f04ac52f80bf","added_by":"auto","created_at":"2025-10-30 10:14:35","extension":"docx","order_by":0,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":57918,"visible":true,"origin":"","legend":"","description":"","filename":"Maindocument.docx","url":"https://assets-eu.researchsquare.com/files/rs-7762159/v1/3780b4b852749924b26c3faf.docx"},{"id":94750493,"identity":"985a238d-3b24-4db8-8845-d80e4981db12","added_by":"auto","created_at":"2025-10-30 10:14:35","extension":"json","order_by":1,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":6445,"visible":true,"origin":"","legend":"","description":"","filename":"29f90c97d3654aa285854a7888927536.json","url":"https://assets-eu.researchsquare.com/files/rs-7762159/v1/aae281f0ea146f5a394d49b1.json"},{"id":94750494,"identity":"19f2c147-bf71-4874-84d5-d19f0816e872","added_by":"auto","created_at":"2025-10-30 10:14:35","extension":"xml","order_by":2,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":90849,"visible":true,"origin":"","legend":"","description":"","filename":"29f90c97d3654aa285854a78889275361enriched.xml","url":"https://assets-eu.researchsquare.com/files/rs-7762159/v1/9e8aa2d96cb009803c40f4c9.xml"},{"id":94750497,"identity":"7be41b86-6970-4a62-a2c3-2313d35bad80","added_by":"auto","created_at":"2025-10-30 10:14:35","extension":"xml","order_by":3,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":91138,"visible":true,"origin":"","legend":"","description":"","filename":"29f90c97d3654aa285854a78889275361structuring.xml","url":"https://assets-eu.researchsquare.com/files/rs-7762159/v1/daa36a3abb1cfccb0364110f.xml"},{"id":94823935,"identity":"ba105b48-f2fa-4eac-a824-38d7b41a1eab","added_by":"auto","created_at":"2025-10-31 06:48:18","extension":"html","order_by":4,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":100873,"visible":true,"origin":"","legend":"","description":"","filename":"earlyproof.html","url":"https://assets-eu.researchsquare.com/files/rs-7762159/v1/5a102c347026c410265b60b5.html"},{"id":95648061,"identity":"29fffb38-b948-4802-bcb2-6900a3bc91dc","added_by":"auto","created_at":"2025-11-11 14:39:07","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1076904,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-7762159/v1/95afc9d1-51c6-4d3b-a509-15afb09d5e09.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Evaluation of trace element contents in canned tomato paste and canned pineapple marketed in Algeria","fulltext":[{"header":"Introduction","content":"\u003cp\u003eNowadays, packaging is extensively utilized across a diverse array of products. The field of food packaging is constantly evolving to meet specific needs and challenges.\u003c/p\u003e\u003cp\u003eMetallic food packaging is widely considered as one of the most effective forms of food packaging materials. Tin can, known for its robustness and excellent barrier properties, minimizes headspace oxygen and allows food sterilization within hermetically sealed can \u003cb\u003e(\u003c/b\u003eMakki \u0026amp; Ziarati, \u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e2014\u003c/span\u003e\u003cb\u003e)\u003c/b\u003e. This ensures a prolonged, safe, ambient shelf life with minimal or no need for preservatives \u003cb\u003e(\u003c/b\u003eMakki \u0026amp; Ziarati, \u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e2014\u003c/span\u003e\u003cb\u003e)\u003c/b\u003e. Furthermore, tin cans exhibit durability against the rigors of storage and transportation, finding use in various food and beverage categories such as vegetables, fruits, meat, dairy products, soft drinks, teas, and more \u003cb\u003e(\u003c/b\u003eGeueke, \u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e2016\u003c/span\u003e\u003cb\u003e)\u003c/b\u003e.\u003c/p\u003e\u003cp\u003eAccording to the \u003cb\u003e(Regulation (EC) No 1935/2004)\u003c/b\u003e, any material or article intended to come into contact directly or indirectly with food must be sufficiently inert to preclude substances from being transferred to food in quantities large enough to endanger human health or to bring about an unacceptable change in the composition of the food or a deterioration in its organoleptic properties.\u003c/p\u003e\u003cp\u003eDuring the last years, canned foods have garnered heightened attention in terms of food safety due to the risk of heavy metal contamination. This contamination arises from the migration of the MTEs from the metallic packaging materials to canned food, this process is strongly influenced by the interactions between food components and packaging material \u003cb\u003e(\u003c/b\u003eArvanitoyannis \u0026amp; Bosnea, \u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e2004\u003c/span\u003e\u003cb\u003e)\u003c/b\u003e.\u003c/p\u003e\u003cp\u003eSeveral factors impact corrosion rates, including thermal treatment, impurities in tinplate, nature of the organic coating, food characteristics (pH, additives, oxidizing agents), oxygen presence in the headspace, and storage conditions (time and temperature) \u003cb\u003e(Noureddine El\u003c/b\u003e Moussawi et al., \u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e2020\u003c/span\u003e).\u003c/p\u003e\u003cp\u003eThe French Food Safety Agency recognizes metallic food packaging as a potential source of MTEs \u003cb\u003e(\u003c/b\u003eAFSSA, \u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2010\u003c/span\u003e\u003cb\u003e)\u003c/b\u003e. Their presence in high levels may affect the organoleptic characteristics of canned foods and expose humans to worrying levels of contamination \u003cb\u003e(\u003c/b\u003eKassouf et al., \u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e2013\u003c/span\u003e).\u003c/p\u003e\u003cp\u003eFe, Zn, Cu, Pb, and Cd represent five potential migrants from metallic packaging and are among the most widely studied in canned foods \u003cb\u003e(\u003c/b\u003eKassouf et al., \u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e2013\u003c/span\u003e; Makki \u0026amp; Ziarati, \u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e2014\u003c/span\u003e; \u003cb\u003eMassadeh \u0026amp; Al-Massaedh, 2018)\u003c/b\u003e. Lead and cadmium possess the highest toxic potential, while other metals may also pose a hazard to humans under specific conditions \u003cb\u003e(\u003c/b\u003eKassouf et al., \u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e2013\u003c/span\u003e).\u003c/p\u003e\u003cp\u003eThere is no recommended maximum level or legal limit for Fe, Zn, and Cu content in foods. However, according to the practical guide published in 2013 by the Committee of Experts on Food and Pharmaceutical Packaging of the Council of Europe, specific migration limits \u0026ldquo;SML\u0026rdquo; for Fe, Zn, and Cu in canned foods have been set (40 mg/Kg, 5 mg/Kg, and 4 mg/Kg, respectively) (Committee of Experts on Packaging Materials for Food and Pharmaceutical Products, \u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e2013\u003c/span\u003e). These limits are based on data provided by industry in European Union member states, indicating that these SMLs are reasonably achievable at present \u003cb\u003e(\u003c/b\u003eCommittee of Experts on Packaging Materials for Food and Pharmaceutical Products, \u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e2013\u003c/span\u003e\u003cb\u003e)\u003c/b\u003e. However, they should be subject to revision to account for advancements in scientific and technical knowledge and improvements in good manufacturing practices \u003cb\u003e(\u003c/b\u003eCommittee of Experts on Packaging Materials for Food and Pharmaceutical Products, \u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e2013\u003c/span\u003e\u003cb\u003e)\u003c/b\u003e.\u003c/p\u003e\u003cp\u003eAs the most toxic heavy metals, the Codex Alimentarius commission (FAO/WHO) has established maximum limits \u0026ldquo;ML\u0026rdquo; for Pb and Cd in canned foods, set at 1 mg/Kg and 0.05 mg/Kg, respectively \u003cb\u003e(Codex STAN 193\u0026ndash;1995)\u003c/b\u003e.\u003c/p\u003e\u003cp\u003eOur study aimed to assess the levels of MTEs (Fe, Zn, Cu, Pb and Cd) in canned tomato paste and canned pineapple from various brands marketed in Algiers, and exploring their relationship with migration factors in tin cans (can condition, headspace, contact time, and pH).\u003c/p\u003e"},{"header":"Materials and methods","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e\u003ch2\u003eSample Collection\u003c/h2\u003e\u003cp\u003eThe study included a total of 52 samples, including 36 samples of canned tomato paste, and 16 samples of canned pineapple. The canned tomato paste samples originated from 12 distinct brands, with three different batches selected for each brand to encompass various manufacturing dates. For canned pineapples, samples were obtained from six brands, with three batches chosen for four brands and two batches for the remaining two brands.\u003c/p\u003e\u003cp\u003eSamples were collected from three to six different stores in Algiers, northern Algeria, over a five-month period (June \u0026ndash; October 2021).\u003c/p\u003e\u003c/div\u003e\n\u003ch3\u003eReagents\u003c/h3\u003e\n\u003cp\u003eAnalytical reagents-grade chemicals were employed for samples processing. Doubly distilled deionized water (18.2 MΩ/cm, resistivity) was used for standards, reagents, and samples preparation. Buffer solutions pH 4.00 and pH 7.00 (Sigma-Aldrich, Germany), nitric acid HNO\u003csub\u003e3\u003c/sub\u003e 60% (HCPro Hygiene Chemicals Production, Algeria), hydrogen peroxide H\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e2\u003c/sub\u003e 10% (PPSP, Algeria), and hydrochloric acid HCl\u0026thinsp;\u0026gt;\u0026thinsp;37% (Fluka Chemika, Germany) were also used. Standard solutions for calibration were prepared by diluting a stock solution of 1000 mg/mL in 3% nitric acid of each tested element Fe, Zn, Cu, Pb, and Cd (Atomic Absorption Standard, Agilent Technologies USA).\u003c/p\u003e\n\u003ch3\u003eApparatus\u003c/h3\u003e\n\u003cp\u003eAquaMax Ultra 370 Series water purification system (Younglin, South Korea) was utilized for distilled water purification. The analytical balance, Axis ALN 120G (Poland), with an accuracy of d\u0026thinsp;=\u0026thinsp;0.1 mg, and the pH meter, HANNA instruments HI 2211 (Holland), with a precision of \u0026plusmn;\u0026thinsp;0.01, were used. The BOSCH universal chopper (Germany) equipped with stainless steel cutters was used to grind pineapple slices.\u003c/p\u003e\u003cp\u003eMTEs measurements were performed using Atomic Absorption Spectrometer (AAS) (Agilent technologies, USA). The 240 FS flame system (FAAS) with deuterium D\u003csub\u003e2\u003c/sub\u003e lamp for background correction was used to Fe, Zn, and Cu measurements. Meanwhile, the measurements of Pb and Cd were carried out by the 240 Z system for graphite furnace atomic absorption (GFAAS), equipped with Zeeman background correction.\u003c/p\u003e\n\u003ch3\u003eAnalysis of Samples\u003c/h3\u003e\n\u003cdiv id=\"Sec7\" class=\"Section2\"\u003e\u003ch2\u003eCan Corrosion\u003c/h2\u003e\u003cp\u003eThe condition of the tin cans was visually inspected. We noted the presence or absence of corrosion on the \u0026ldquo;exterior\u0026rdquo; surface of the cans and recorded the intensity of corrosion (weak or strong).\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec8\" class=\"Section2\"\u003e\u003ch2\u003eContact Time\u003c/h2\u003e\u003cp\u003eThe interaction time between canned food samples and the tin cans was expressed in days. Calculations involved determining the duration from the manufacturing date to the date of can opening.\u003c/p\u003e\u003c/div\u003e\n\u003ch3\u003eHeadspace\u003c/h3\u003e\n\u003cp\u003eThe headspace was measured as the (volume) between the product and the can lid. Using a caliper, the height of the headspace \u0026ldquo;h\u0026rdquo; was recorded in centimeters (cm). the volume \u0026ldquo;V\u0026rdquo; was calculated with the formula: \u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\:{\\varvec{V}\\:\\left({\\varvec{c}\\varvec{m}}^{3}\\right)}_{\\:}=\\:{\\left(\\frac{\\varvec{d}}{2}\\right)}^{2}\\:\\times\\:\\:\\varvec{\\pi\\:}\\:\\times\\:\\:\\varvec{h}\\:=\\:{\\varvec{r}}^{2}\\:\\times\\:\\:\\varvec{\\pi\\:}\\:\\times\\:\\:\\varvec{h}\\:\\)\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\u003cp\u003eWhere: d\u0026thinsp;=\u0026thinsp;diameter of cans (cm); h\u0026thinsp;=\u0026thinsp;height of the headspace (cm); r\u0026thinsp;=\u0026thinsp;radius of cans (cm).\u003c/p\u003e\n\u003ch3\u003eMeasurement of pH\u003c/h3\u003e\n\u003cp\u003eManual homogenization was done for canned tomato paste samples, and the pH was measured after dissolving 2.0 g\u0026thinsp;\u0026plusmn;\u0026thinsp;0.1 mg in ultrapure distilled water. Meanwhile, for canned pineapples, pH measurement was performed directly by immersing probes into the covering liquid.\u003c/p\u003e\u003cdiv id=\"Sec11\" class=\"Section2\"\u003e\u003ch2\u003eSamples Preparation and Acid Digestion Method\u003c/h2\u003e\u003cp\u003eIn this study, the tested canned food samples were prepared following these steps:\u003c/p\u003e\u003cp\u003e\u003cul\u003e\u003cli\u003e\u003cp\u003eEach canned food sample was thoroughly homogenized. Decontaminated glass spatulas were used for the canned tomato paste samples, while the universal chopper with stainless steel cutter was employed for the canned pineapple samples.\u003c/p\u003e\u003c/li\u003e\u003cli\u003e\u003cp\u003e1.0 g\u0026thinsp;\u0026plusmn;\u0026thinsp;0.1 mg of homogenized food sample placed in a decontaminated balloon glassware.\u003c/p\u003e\u003c/li\u003e\u003cli\u003e\u003cp\u003eMineralization using a modified wet digestion method \u003cb\u003e(\u003c/b\u003eDemirel et al., \u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e2008\u003c/span\u003e; Saracoglu et al., \u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e2007\u003c/span\u003e) with a mixture of HNO\u003csub\u003e3\u003c/sub\u003e:H\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e2\u003c/sub\u003e (3:2). Twenty-five milliliters of the mixture were utilized for each 1.0 g sample, followed by the addition of 0.5 mL of HCl. The resulting mixtures were heated to 150\u0026deg;C for 2 \u0026frac12; hours.\u003c/p\u003e\u003c/li\u003e\u003cli\u003e\u003cp\u003eFiltration into 50 mL volumetric flask after cooling, and dilution with deionized water.\u003c/p\u003e\u003c/li\u003e\u003cli\u003e\u003cp\u003eA blank solution was prepared following the same procedure.\u003c/p\u003e\u003c/li\u003e\u003cli\u003e\u003cp\u003eAll collected samples and the blank test were stored in polypropylene tubes at room temperature until analysis.\u003c/p\u003e\u003c/li\u003e\u003c/ul\u003e\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec12\" class=\"Section2\"\u003e\u003ch2\u003eQuantitative Determination of the Trace Elements\u003c/h2\u003e\u003cp\u003eCalibration was conducted with five aqueous standards, including a blank. For Fe, Zn, and Cu calibration, we used solutions from 0.2 to 2.0 mg/L, while, for Pb, and Cd the solutions were from 20 to 100 \u0026micro;g/L.\u003c/p\u003e\u003cp\u003eAAS analysis was carried out at the most analytical spectral lines of the metals: (Fe 248.3 nm, Zn 213.9 nm, and Cu 324.8 nm) by the FAAS using an air-acetylene flame, and (Cd 228.8 nm and Pb 283.3 nm) by GFAAS using argon as an inert gas.\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec13\" class=\"Section2\"\u003e\u003ch2\u003eData Analysis\u003c/h2\u003e\u003cp\u003eIn this study, we performed descriptive analysis on all the dataset outcomes. Furthermore, we performed comparative univariate tests between the results of the two analyzed samples categories (canned tomato paste and canned pineapple), and between the obtained results and regulatory limit values. Subsequently, a correlation matrix was applied to the nine variables inherent from dataset: pH levels, headspaces, contact times, can corrosion, and the five MTEs under evaluation.\u003c/p\u003e\u003cp\u003eAll analysis were performed using R statistical software version 4.3.2.\u003c/p\u003e\u003c/div\u003e"},{"header":"Results","content":"\u003cp\u003eThe can condition was coded as follows: 1 for cans in good condition (no corrosion), 2 if the cans exhibited slight corrosion, and 3 for heavy corrosion. The results obtained are summarized in Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e.\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\u003eExternal states of cans checked for the two categories of samples.\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"3\"\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\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cem\u003eSample\u003c/em\u003e\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u003cem\u003eModality\u003c/em\u003e\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003e\u003cem\u003eFrequency (%)\u003c/em\u003e\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\" morerows=\"2\" rowspan=\"3\"\u003e\u003cp\u003e\u003cb\u003eCanned tomato paste\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e1\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e63.89\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e2\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e25.00\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e3\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e11.11\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\" morerows=\"2\" rowspan=\"3\"\u003e\u003cp\u003e\u003cb\u003eCanned pineapple\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e1\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e87.50\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e2\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e12.50\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e3\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e0.00\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\u003eThe average values of headspaces, food-packaging contact time, and pH values of the studied samples are provided in Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e.\u003c/p\u003e\u003cp\u003e\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab2\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e\u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e\u003cdiv class=\"CaptionContent\"\u003e\u003cp\u003eResults obtained for the various factors studied influencing the migration of MTEs from cans to packaged food.\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"6\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" 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=\"char\" char=\".\" 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\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u003cem\u003eSamples\u003c/em\u003e\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003e\u003cem\u003eMin\u003c/em\u003e\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\u003e\u003cp\u003e\u003cem\u003eMax\u003c/em\u003e\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c5\"\u003e\u003cp\u003e\u003cem\u003eMean\u003c/em\u003e\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c6\"\u003e\u003cp\u003e\u003cem\u003eSD (n-1)\u003c/em\u003e*\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e\u003cp\u003e\u003cb\u003eHeadspace (cm\u003c/b\u003e\u003csup\u003e\u003cb\u003e3\u003c/b\u003e\u003c/sup\u003e\u003cb\u003e)\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u003cb\u003eCanned tomato paste\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e0.00\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e74.62\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e23.56\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e21.16\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u003cb\u003eCanned pineapple\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e0.00\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e69.24\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e18.75\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e22.82\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e\u003cp\u003e\u003cb\u003eContact time (days)\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u003cb\u003eCanned tomato paste\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e59.00\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e610.00\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e250.44\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e116.44\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u003cb\u003eCanned pineapple\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e199.00\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e553.00\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e278.81\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e86.80\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e\u003cp\u003e\u003cb\u003epH\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u003cb\u003eCanned tomato paste\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e4.19\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e4.63\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e4.41\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e0.09\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u003cb\u003eCanned pineapple\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e3.39\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e3.86\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e3.64\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e0.14\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\u003cstrong\u003e*\u003cem\u003eSD (n-1)\u003c/em\u003e\u003c/strong\u003e\u003cp\u003eStandard Deviation.\u003c/p\u003e\u003c/p\u003e\u003cp\u003eThe headspaces values for cans in the two studied food categories were compared and the results indicated no statistically significant difference (p\u0026thinsp;=\u0026thinsp;0,46) \u003cb\u003e(\u003c/b\u003eTable\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e\u003cb\u003e)\u003c/b\u003e. Meanwhile, the pH values measured for canned tomato paste and canned pineapple revealed statistically significant difference (p\u0026thinsp;\u0026lt;\u0026thinsp;0.0001) \u003cb\u003e(\u003c/b\u003eTable\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e\u003cb\u003e)\u003c/b\u003e.\u003c/p\u003e\u003cp\u003eThe maximum allowable pH level for canned tomato paste is 4.5 \u003cb\u003e(Codex STAN 13-1981)\u003c/b\u003e. We compared the measured pH values for canned tomato paste samples with this threshold value, and the test indicated that the pH values obtained are statistically lower than the threshold value (p\u0026thinsp;\u0026lt;\u0026thinsp;0.0001). Out of the 36 analyzed samples, only one showed a pH value exceeding the threshold (pH\u0026thinsp;=\u0026thinsp;4.63\u0026thinsp;\u0026plusmn;\u0026thinsp;0.01).\u003c/p\u003e\u003cp\u003eFor canned pineapple, there is no specific pH limit according to Codex standards \u003cb\u003e(Codex STAN 42-1981)\u003c/b\u003e. However, pineapple pH values can range from 3.20 to 4.00 \u003cb\u003e(\u003c/b\u003eDowning, \u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e1996\u003c/span\u003e\u003cb\u003e)\u003c/b\u003e. All measured pH values for the canned pineapple samples fell within this interval, ranging from a minimum of (pH\u0026thinsp;=\u0026thinsp;3.39\u0026thinsp;\u0026plusmn;\u0026thinsp;0.01) to a maximum of (pH\u0026thinsp;=\u0026thinsp;3.86\u0026thinsp;\u0026plusmn;\u0026thinsp;0.01).\u003c/p\u003e\u003cp\u003eThe mean concentrations of the MTEs measured in the 52 samples are presented in Table\u0026nbsp;\u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e.\u003c/p\u003e\u003cp\u003e\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab3\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e\u003cdiv class=\"CaptionNumber\"\u003eTable 3\u003c/div\u003e\u003cdiv class=\"CaptionContent\"\u003e\u003cp\u003eConcentrations of MTEs (mg/Kg) obtained in the two categories of samples.\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"6\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" 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=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cem\u003eMTE\u003c/em\u003e\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u003cem\u003eSample\u003c/em\u003e\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003e\u003cem\u003eMin\u003c/em\u003e\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\u003e\u003cp\u003e\u003cem\u003eMax\u003c/em\u003e\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c5\"\u003e\u003cp\u003e\u003cem\u003eMean\u003c/em\u003e\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c6\"\u003e\u003cp\u003e\u003cem\u003eSD (n-1)\u003c/em\u003e*\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e\u003cp\u003e\u003cb\u003eFe\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u003cb\u003eCanned tomato paste\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e1.30\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e48.35\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e18.15\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e10.92\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u003cb\u003eCanned pineapple\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0.18\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e6.38\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e2.12\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e1.96\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e\u003cp\u003e\u003cb\u003eZn\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u003cb\u003eCanned tomato paste\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0.38\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e5.42\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e2.53\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e1.36\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u003cb\u003eCanned pineapple\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e\u0026lt; LOQ\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e3.62\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.61\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e0.99\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e\u003cp\u003e\u003cb\u003eCu\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u003cb\u003eCanned tomato paste\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e\u0026lt; LOQ\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e23.00\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e2.36\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e4.13\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u003cb\u003eCanned pineapple\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e\u0026lt; LOQ\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e1.65\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.88\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e0.46\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e\u003cp\u003e\u003cb\u003eCd\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u003cb\u003eCanned tomato paste\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e\u0026lt; LOQ\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e2.45\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.14\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e0.43\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u003cb\u003eCanned pineapple\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e\u0026lt; LOQ\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e1.34\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.18\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e0.43\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e\u003cp\u003e\u003cb\u003ePb\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u003cb\u003eCanned tomato paste\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e\u0026lt; LOQ\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.12\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.003\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e0.02\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u003cb\u003eCanned pineapple\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e\u0026lt; LOQ\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e\u0026lt; LOQ\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e/\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e/\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\u003cstrong\u003e*\u003cem\u003eSD (n-1)\u003c/em\u003e\u003c/strong\u003e\u003cp\u003eStandard Deviation.\u003c/p\u003e\u003c/p\u003e\u003cp\u003eThe concentrations of Fe, Zn, and Cu obtained in the canned tomato paste samples were statistically higher than those obtained in the canned pineapple samples, with p-values of (p\u0026thinsp;\u0026lt;\u0026thinsp;0.0001), (p\u0026thinsp;=\u0026thinsp;0.0319), and (p\u0026thinsp;\u0026lt;\u0026thinsp;0.0001), respectively.\u003c/p\u003e\u003cp\u003eHowever, the statistical tests revealed that there is no statistically significant difference between the analyzed canned tomato paste and canned pineapple regarding the concentration of Cd and Pb obtained (p\u0026thinsp;=\u0026thinsp;0.5593 and p\u0026thinsp;=\u0026thinsp;0.9804, respectively).\u003c/p\u003e\u003cp\u003eCorrelation matrix was performed on all the studied parameters. This was accomplished using Pearson correlation matrices, which are illustrated in \u003cb\u003eTable [4\u0026ndash;5]\u003c/b\u003e.\u003c/p\u003e\u003cp\u003eFor canned tomato paste, the correlation matrix \u003cb\u003e(\u003c/b\u003eTable\u0026nbsp;\u003cspan refid=\"Tab4\" class=\"InternalRef\"\u003e4\u003c/span\u003e\u003cb\u003e)\u003c/b\u003e revealed that the Zn and Cu content were negatively correlated with the pH values, (r\u0026thinsp;=\u0026thinsp;\u0026minus;\u0026thinsp;0.46) and (r\u0026thinsp;=\u0026thinsp;\u0026minus;\u0026thinsp;0.45), respectively. Zn content and Cu content were positively correlated (r\u0026thinsp;=\u0026thinsp;0.40). Fe content and contact time were also positively correlated (r\u0026thinsp;=\u0026thinsp;0.31).\u003c/p\u003e\u003cp\u003eFor canned pineapple, the correlation matrix \u003cb\u003e(\u003c/b\u003eTable\u0026nbsp;\u003cspan refid=\"Tab5\" class=\"InternalRef\"\u003e5\u003c/span\u003e\u003cb\u003e)\u003c/b\u003e reveals a positive correlation between Fe content and headspace (r\u0026thinsp;=\u0026thinsp;0.60). Zn and Cd contents were positively correlated (r\u0026thinsp;=\u0026thinsp;0.58), and both were positively correlated with food-packaging contact time, (r\u0026thinsp;=\u0026thinsp;0.59) and (r\u0026thinsp;=\u0026thinsp;0.53), respectively.\u003c/p\u003e\u003cp\u003e\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab4\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e\u003cdiv class=\"CaptionNumber\"\u003eTable 4\u003c/div\u003e\u003cdiv class=\"CaptionContent\"\u003e\u003cp\u003eCorrelation matrix coefficients between the MTEs assayed in the canned tomato paste samples and the four factors influencing migration.\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"10\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" 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=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c8\" colnum=\"8\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c9\" colnum=\"9\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c10\" colnum=\"10\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u003cp\u003eVariables\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003eCan condition\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003eHeadspace\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\u003e\u003cp\u003eContact time\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c5\"\u003e\u003cp\u003epH\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c6\"\u003e\u003cp\u003eFe\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c7\"\u003e\u003cp\u003eCu\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c8\"\u003e\u003cp\u003eZn\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c9\"\u003e\u003cp\u003eCd\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c10\"\u003e\u003cp\u003ePb\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u003cp\u003eCan condition\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003e1\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/th\u003e\u003cth align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/th\u003e\u003cth align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/th\u003e\u003cth align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/th\u003e\u003cth align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/th\u003e\u003cth align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/th\u003e\u003cth align=\"left\" colname=\"c10\"\u003e\u0026nbsp;\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eHeadspace\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e0.11\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e\u003cb\u003e1\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c10\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eContact time\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e0.19\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e-0.04\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e\u003cb\u003e1\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c10\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003epH\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e-0.27\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0.03\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e-0.10\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e\u003cb\u003e1\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c10\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eFe\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e0\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e-0.20\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e\u003cb\u003e0.31\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.14\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e\u003cb\u003e1\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c10\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eCu\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e0.29\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0.02\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.13\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e\u003cb\u003e-0.45\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e0.02\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e\u003cb\u003e1\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c10\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eZn\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e0.04\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e-0.01\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.07\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e\u003cb\u003e-0.46\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e0.22\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e\u003cb\u003e0.40\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c8\"\u003e\u003cp\u003e\u003cb\u003e1\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c10\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eCd\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e0.25\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0.28\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.16\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.17\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e-0.03\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e-0.04\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c8\"\u003e\u003cp\u003e0.19\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c9\"\u003e\u003cp\u003e\u003cb\u003e1\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c10\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003ePb\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e0.13\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0.05\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e-0.24\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.10\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e-0.17\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e-0.01\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c8\"\u003e\u003cp\u003e-0.24\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c9\"\u003e\u003cp\u003e-0.05\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c10\"\u003e\u003cp\u003e\u003cb\u003e1\u003c/b\u003e\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\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab5\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e\u003cdiv class=\"CaptionNumber\"\u003eTable 5\u003c/div\u003e\u003cdiv class=\"CaptionContent\"\u003e\u003cp\u003eCorrelation matrix coefficients between the MTEs assayed in the canned pineapple samples and the four factors influencing migration.\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"9\"\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=\"left\" 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=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c8\" colnum=\"8\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c9\" colnum=\"9\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u003cp\u003eVariables\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003eCan condition\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003eHeadspace\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\u003e\u003cp\u003eContact time\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c5\"\u003e\u003cp\u003epH\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c6\"\u003e\u003cp\u003eFe\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c7\"\u003e\u003cp\u003eCu\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c8\"\u003e\u003cp\u003eZn\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c9\"\u003e\u003cp\u003eCd\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u003cp\u003eCan condition\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003e1\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/th\u003e\u003cth align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/th\u003e\u003cth align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/th\u003e\u003cth align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/th\u003e\u003cth align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/th\u003e\u003cth align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eHeadspace\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e-0.26\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e\u003cb\u003e1\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eContact time\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e-0.01\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e-0.24\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e\u003cb\u003e1\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003epH\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e0.39\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e-0.10\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.21\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e\u003cb\u003e1\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eFe\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e-0.34\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e\u003cb\u003e0.60\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.10\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.16\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e\u003cb\u003e1\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eCu\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e0.15\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e-0.09\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e-0.06\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e-0.07\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e-0.62\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e\u003cb\u003e1\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eZn\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e0.03\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e-0.03\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e\u003cb\u003e0.59\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.07\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e-0.06\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e-0.11\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c8\"\u003e\u003cp\u003e\u003cb\u003e1\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eCd\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e-0.16\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e-0.27\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e\u003cb\u003e0.53\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e-0.11\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e-0.21\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e0.12\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c8\"\u003e\u003cp\u003e\u003cb\u003e0.58\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e\u003cp\u003e\u003cb\u003e1\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eThe results indicate that Fe was the most dominant MTE in canned tomato paste samples, with an average concentration of (18.15\u0026thinsp;\u0026plusmn;\u0026thinsp;10.92 mg/Kg), followed by Zn (2.53\u0026thinsp;\u0026plusmn;\u0026thinsp;1.36 mg/Kg), Cu (2.36\u0026thinsp;\u0026plusmn;\u0026thinsp;4.13 mg/Kg), Cd (0.14\u0026thinsp;\u0026plusmn;\u0026thinsp;0.43 mg/Kg), and finally Pb (0.003\u0026thinsp;\u0026plusmn;\u0026thinsp;0.02 mg/Kg). These findings align with those reported by \u003cb\u003e(\u003c/b\u003eSafta et al., \u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e2020\u003c/span\u003e), who analyzed canned tomato paste samples in Tunisia. Their study revealed Fe as the most abundant MTE with an average of (18.81\u0026thinsp;\u0026plusmn;\u0026thinsp;2.71 mg/Kg), followed by Zn and Cu with averages of (3.61\u0026thinsp;\u0026plusmn;\u0026thinsp;1.80 mg/Kg) and (1.51\u0026thinsp;\u0026plusmn;\u0026thinsp;0.35 mg/Kg), respectively \u003cb\u003e(\u003c/b\u003eSafta et al., \u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e2020\u003c/span\u003e). However, Cd levels were lower than our results at (0.05\u0026thinsp;\u0026plusmn;\u0026thinsp;0.01 mg/Kg), and Pb was not detected in the canned tomato paste analyzed by \u003cb\u003e(\u003c/b\u003eSafta et al., \u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e2020\u003c/span\u003e).\u003c/p\u003e\u003cp\u003eIn the canned pineapple samples, Fe emerged as the most abundant element, averaging (2.12\u0026thinsp;\u0026plusmn;\u0026thinsp;1.96 mg/Kg), followed by Cu (0.88\u0026thinsp;\u0026plusmn;\u0026thinsp;0.46 mg/Kg), Zn (0.61\u0026thinsp;\u0026plusmn;\u0026thinsp;0.99 mg/Kg), Cd (0.18\u0026thinsp;\u0026plusmn;\u0026thinsp;0.43 mg/Kg), while Pb was not detected (\u0026lt;\u0026thinsp;LOQ). A study conducted by Massadeh et al., (\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e2018\u003c/span\u003e) on canned pineapple samples in Jordan yielded non-comparable results, with Pb averaging (2.80\u0026thinsp;\u0026plusmn;\u0026thinsp;0.35 mg/Kg), followed by Cu (0.91\u0026thinsp;\u0026plusmn;\u0026thinsp;0.03 mg/Kg), Cd (0.56\u0026thinsp;\u0026plusmn;\u0026thinsp;0.02 mg/Kg), and Zn (0.32\u0026thinsp;\u0026plusmn;\u0026thinsp;0.26 mg/Kg).\u003c/p\u003e\u003cp\u003eFrom the statistical results, the difference found between the Fe, Zn, and Cu contents in canned tomato paste and canned pineapple may be attributed to the acidic nature of canned tomato paste, coupled with the presence of added salt as a stabilizer, which can promote corrosion and elevate iron content \u003cb\u003e(\u003c/b\u003eSafta et al., \u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e2020\u003c/span\u003e). The elevated level of Fe migration in canned tomato paste may also be attributed to the interaction of the metal surface with nitrates present in heavily fertilized soils \u003cb\u003e(\u003c/b\u003eBarone et al., \u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e2015\u003c/span\u003e). This is due to the reduction of nitrate anions by various intermediates to ammonia, which serves as corrosion accelerators in tomato products \u003cb\u003e(\u003c/b\u003eBarone et al., \u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e2015\u003c/span\u003e).\u003c/p\u003e\u003cp\u003eOut of the 36 analyzed samples of canned tomato paste, two exhibited Fe migration values exceeding the threshold (40 mg of Fe/Kg), two other samples surpassed the SML of Zn (5 mg of Zn/Kg), and two samples had Cu content exceeding the migration threshold (4 mg of Cu/Kg). In contrast, eight out of the 36 samples of canned tomato paste exceeded the limit for cadmium (0.05 mg of Cd/Kg). However, all the analyzed samples of canned tomato paste showed levels below the regulatory limit for Pb (1 mg of Pb/Kg).\u003c/p\u003e\u003cp\u003eThe canned pineapple samples, in contrast, demonstrated concentrations below the regulatory limits for Fe, Zn, Cu, and Pb. Nevertheless, three samples out of the 16 analyzed samples exceeded the limit set by the Codex for Cd.\u003c/p\u003e\u003cp\u003eHowever, we conducted statistical tests to compare the concentrations obtained with the regulatory limits. The concentrations of Fe, Zn, Cu, and Pb for both sample categories are statistically lower than the regulatory limits (p\u0026thinsp;\u0026le;\u0026thinsp;0.01). The statistical tests were non-significant for the Cd concentrations in the two samples categories compared to ML. In this case, increasing the sample size is necessary to elucidate the significance of the measured contents for both sample categories.\u003c/p\u003e\u003cp\u003eThe correlation matrix \u003cb\u003e(\u003c/b\u003eTable\u0026nbsp;\u003cspan refid=\"Tab4\" class=\"InternalRef\"\u003e4\u003c/span\u003e\u003cb\u003e)\u003c/b\u003e reveals a negative correlation between Zn and Cu content in canned tomato paste and the pH values. In the literature, the pH of canned foods has been identified as a factor influencing the corrosion of metal cans used in food packaging; lower pH levels tend to accelerate corrosion, directly impacting the migration of certain MTEs from the packaging materials to the packaged food product \u003cb\u003e(\u003c/b\u003eRobertson, \u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e2016\u003c/span\u003e\u003cb\u003e)\u003c/b\u003e. Buculei et al., \u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e2014\u003c/span\u003e, observed that can corrosion is favored when the pH values of canned food fall within the range of [3.50\u0026ndash;4.00]. They further noted that the presence of certain organic acids, such as citric acid and malic acid, can enhance can corrosion \u003cb\u003e(\u003c/b\u003eBuculei et al., \u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e2014\u003c/span\u003e). We also find a weak positive correlation between Zn content and Cu content in canned tomato paste. This observation can be explained by the fact that Cu acts as a depolarizer, accelerating the corrosion of steel by catalyzing the reduction of oxygen \u003cb\u003e(\u003c/b\u003eRobertson, \u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e2016\u003c/span\u003e\u003cb\u003e)\u003c/b\u003e. Cu can potentially enter foodstuffs through the application of copper-based pesticides commonly used on farms in certain countries \u003cb\u003e(\u003c/b\u003eOnianwa et al., \u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e2001\u003c/span\u003e).\u003c/p\u003e\u003cp\u003eFor canned pineapple, the correlation matrix \u003cb\u003e(\u003c/b\u003eTable\u0026nbsp;\u003cspan refid=\"Tab5\" class=\"InternalRef\"\u003e5\u003c/span\u003e\u003cb\u003e)\u003c/b\u003e reveals a positive correlation between Fe content and headspace. The headspace influences the corrosion of metal cans, which is why it is recommended to minimize it. This reduction aims to decrease the oxygen level in cans, thereby increasing the shelf life of packaged foods \u003cb\u003e(\u003c/b\u003ePerring \u0026amp; Basic-Dvorzak, \u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e2002\u003c/span\u003e; Robertson, \u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e2016\u003c/span\u003e\u003cb\u003e)\u003c/b\u003e. Zn and Cd levels exhibit a positive correlation with food-packaging contact time. Experimental data indicate that the concentration of the migrating compound is directly proportional to the square root of contact time \u003cb\u003e(\u003c/b\u003eArvanitoyannis \u0026amp; Kotsanopoulos, \u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e2014\u003c/span\u003e\u003cb\u003e)\u003c/b\u003e. Zn contents are also positively correlated with Cd contents, this correlation can be explained by the presence of Cd in Zn ores \u003cb\u003e(\u003c/b\u003eCommittee of Experts on Packaging Materials for Food and Pharmaceutical Products, \u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e2013\u003c/span\u003e\u003cb\u003e)\u003c/b\u003e. It is crucial to note that the contamination of samples by Zn can be attributed to its use in the manufacturing of galvanized steel, where zinc functions as an anti-rust coating on Fe or other metals due to its strong reducing agent properties \u003cb\u003e(\u003c/b\u003eCommittee of Experts on Packaging Materials for Food and Pharmaceutical Products, \u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e2013\u003c/span\u003e\u003cb\u003e)\u003c/b\u003e. Additionally, it should be emphasized that Zn is a component of fertilizers \u003cb\u003e(\u003c/b\u003eCommittee of Experts on Packaging Materials for Food and Pharmaceutical Products, \u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e2013\u003c/span\u003e\u003cb\u003e)\u003c/b\u003e. Food contamination by Cd may be linked to its presence as an impurity in the alloys used for can manufacturing \u003cb\u003e(\u003c/b\u003eSafta et al., \u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e2020\u003c/span\u003e). Another possible contributing factor is the prior contamination of fresh foods by phosphate fertilizers or sewage sludge used on some farmlands \u003cb\u003e(\u003c/b\u003eCommittee of Experts on Packaging Materials for Food and Pharmaceutical Products, \u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e2013\u003c/span\u003e\u003cb\u003e)\u003c/b\u003e.\u003c/p\u003e\u003cp\u003eNo correlation was observed between the content of MTEs and the can condition. External corrosion is likely attributed to environmental factors such as food residues, the quality of process water or steam, corrosive glues or labels, as well as improper handling and storage conditions of the cans (temperature, humidity) \u003cb\u003e(\u003c/b\u003eAbdel-Rahman, \u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e2015\u003c/span\u003e\u003cb\u003e)\u003c/b\u003e.\u003c/p\u003e"},{"header":"Conclusion","content":"\u003cp\u003eThe results indicated that around 29% of the analyzed samples did not meet the regulations concerning the presence of MTEs in canned foodstuffs. This includes cadmium, with 11 out of the 52 analyzed samples (21%) surpassing its ML (0.05 mg/Kg).\u003c/p\u003e\u003cp\u003eTherefore, our study successfully identified the presence of some MTEs in canned tomato paste and canned pineapple, revealing correlation with certain factors (pH value, contact time, and headspace). This serves as a preliminary investigation that could be enhanced through a multicenter study conducted over an extended period, involving a larger sample size, and using more advanced analysis methods to validate and extend the findings.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eData availability\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe data presented in this study are available on request from the corresponding author. Due to the confidential nature of the brand names analyzed, the raw data are not publicly available.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompeting interests\u003c/strong\u003e\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eThe authors do not have any conflict of interest.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors did not receive support from any organization for the submitted work.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthors\u0026rsquo; contributions\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eConceptualization: C.B. and S.L.; Methodology: C.B., S.L. and M.M.; Data curation: C.B.; Formal analysis and investigation: N.A. and C.B.; Write \u0026ndash; original draft preparation: C.B.; Write \u0026ndash; review and editing: S.L. and N.A.; Supervision: O.H. all authors have read and agreed to the published version of the manuscript.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAcknowledgements\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eReagents and materials used for this stady were provided and financed by Centre de Recherche Scientifique et Technique en Analyses Physico-Chimiques, Bou-Ismail, Tipaza, Algeria. We are grateful to Mr. Walid Rezgui for his technical assistance and expertise in performing the SAA analysis of the samples.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eEthic statement\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors confirm that this study did not involve \u003cem\u003ehuman participants\u003c/em\u003e or \u003cem\u003elive animals\u003c/em\u003e. This research was conducted on \u003cem\u003einert materials\u003c/em\u003e, specifically food samples. The names of the brands analyzed have been kept \u003cem\u003eanonymous\u003c/em\u003e to maintain objectivity and \u003cem\u003econfidentiality\u003c/em\u003e. All methods were carried out in accordance with \u003cem\u003eethical guidelines\u003c/em\u003e for scientific analysis.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eAbdel-Rahman NAG (2015) Tin-plate corrosion in canned foods. Journal of Global Biosciences 4(7):2966\u0026ndash;2971.\u003c/li\u003e\n\u003cli\u003eAFSSA (2010). Avis de l\u0026apos;Agence Fran\u0026ccedil;aise de S\u0026eacute;curit\u0026eacute; Sanitaire des Aliments relatif au projet de r\u0026eacute;solution du Conseil de l\u0026apos;Europe sur les m\u0026eacute;taux et alliages utilis\u0026eacute;s dans les mat\u0026eacute;riaux et objets destin\u0026eacute;s au contact des denr\u0026eacute;es alimentaires. Saisine n\u0026deg;2010-Sa-0119. https://www.anses.fr/fr/system/files/MCDA2010sa0119.pdf.\u003c/li\u003e\n\u003cli\u003eArvanitoyannis IS, Bosnea L (2004) Migration of substances from food packaging materials to foods. Critical Reviews in Food Science and Nutrition 44(2):63\u0026ndash;76. https://doi.org/10.1080/10408690490424621\u003c/li\u003e\n\u003cli\u003eArvanitoyannis IS, Kotsanopoulos KV (2014) Migration phenomenon in food packaging. Food\u0026ndash;package interactions, mechanisms, types of migrants, testing and relative legislation:A Review. Food and Bioprocess Technology 7(1):21\u0026ndash;36. https://doi.org/10.1007/s11947-013-1106-8\u003c/li\u003e\n\u003cli\u003eBarone C, Bolzoni L, Caruso G, Montanari A, Parisi S, Steinka I (2015) Food packaging hygiene. Springer International Publishing, pp. 122\u0026ndash;123. https://doi.org/10.1007/978-3-319-14827-4\u003c/li\u003e\n\u003cli\u003eBuculei A, Amariei S, Oroian M, Gutt G, Gaceu L, Birca A (2014) Metals migration between product and metallic package in canned meat. LWT - Food Science and Technology 58(2):364\u0026ndash;374. https://doi.org/10.1016/j.lwt.2013.06.003\u003c/li\u003e\n\u003cli\u003eCommittee of Experts on Packaging Materials for Food and Pharmaceutical Products (2013) Metals and alloys used in food contact materials and articles: A practical guide for manufacturers and regulators. European Directorate for the Quality of Medicines \u0026amp; HealthCare (EDQM).\u003c/li\u003e\n\u003cli\u003eDemirel S, Tuzen M, Saracoglu S, Soylak M (2008) Evaluation of various digestion procedures for trace element contents of some food materials. Journal of Hazardous Materials 152(3):1020\u0026ndash;1026. https://doi.org/10.1016/j.jhazmat.2007.07.077\u003c/li\u003e\n\u003cli\u003eDowning DL (1996) CHAPTER 2\u0026mdash;Canning of Fruits. In D. L. Downing (Ed.), A Complete Course in Canning and Related Processes, Thirteenth Edition. Woodhead Publishing, pp. 129\u0026ndash;192. https://doi.org/10.1533/9781845696214.129\u003c/li\u003e\n\u003cli\u003eEC (2004) Regulation No 1935/2004 of the European Parliament and of the Council of 27 October 2004 on materials and articles intended to come into contact with food and repealing Directives 80/590/EEC and 89/109/EEC. JO L 338, 13.11.2004, p. 4.\u003c/li\u003e\n\u003cli\u003eFAO and WHO (1995) General standard for contaminants and toxins in food and feed. Codex Alimentarius commission (Codex STAN 193-1995). \u003c/li\u003e\n\u003cli\u003eFAO and WHO (1981) Norme pour les ananas en conserve. Commission du Codex Alimentarius (Codex STAN 42-1981).\u003c/li\u003e\n\u003cli\u003eFAO and WHO (1981) Standard for preserved tomatoes. Codex Alimentarius commission (Codex STAN 13-1981).\u003c/li\u003e\n\u003cli\u003eGeueke B (2016) Dossier - Can coatings. Food Packaging Forum, 1-10. DOI: 10.5281/zenodo.200633.\u003c/li\u003e\n\u003cli\u003eKassouf A, Chebib H, Lebbos N, Ouaini R (2013) Migration of iron, lead, cadmium and tin from tinplate-coated cans into chickpeas. Food Additives \u0026amp; Contaminants: Part A 30(11):1987\u0026ndash;1992. https://doi.org/10.1080/19440049.2013.832399\u003c/li\u003e\n\u003cli\u003eMakki FM, Ziarati P (2014) Determination of histamine and heavy metal concentrations in tomato pastes and fresh tomato (\u003cem\u003eSolanum lycopersicum\u003c/em\u003e) in Iran. Biosciences Biotechnology Research Asia 11(2):537\u0026ndash;544. https://doi.org/10.13005/bbra/1304\u003c/li\u003e\n\u003cli\u003eMassadeh AM, Al-Massaedh \u0026ldquo;Ayat Allah\u0026rdquo; T (2018) Determination of heavy metals in canned fruits and vegetables sold in Jordan market. Environmental Science and Pollution Research 25(2):1914\u0026ndash;1920. https://doi.org/10.1007/s11356-017-0611-0\u003c/li\u003e\n\u003cli\u003eNoureddine El Moussawi S, Camel V, Cladi\u0026egrave;re M, Lebbos N, Ch\u0026eacute;bib H, Ouaini R (2020) Parameters influencing the migration of trace metals in uncoated fruit cans. Journal of Food Processing and Preservation 44(9): 1\u0026ndash;12. https://doi.org/10.1111/jfpp.14653\u003c/li\u003e\n\u003cli\u003eOnianwa PC, Adeyemo AO, Idowu OE, Ogabiela EE (2001) Copper and zinc contents of Nigerian foods and estimates of the adult dietary intakes. Food Chemistry, 72(1):89\u0026ndash;95. https://doi.org/10.1016/S0308-8146(00)00214-4\u003c/li\u003e\n\u003cli\u003ePerring L., Basic-Dvorzak M. (2002) Determination of total tin in canned food using inductively coupled plasma atomic emission spectroscopy. Analytical and Bioanalytical Chemistry, 374(2):235\u0026ndash;243. https://doi.org/10.1007/s00216-002-1420-x\u003c/li\u003e\n\u003cli\u003eRobertson GL (2016) Food Packaging Principles and Practice Third Edition, Taylor \u0026amp; Francis Group, pp. 214\u0026ndash;219. https://doi.org/10.1201/b21347\u003c/li\u003e\n\u003cli\u003eSafta M., Limam I., Jebali R., Marzouki M., Driss MR., Kalfat R. (2020). Monitoring of metals migration and identification of corrosion sources in canned tomatoes and sardines. International Journal of Environmental Analytical Chemistry, 3:4664\u0026ndash;4677. https://doi.org/10.1080/03067319.2020.1786550\u003c/li\u003e\n\u003cli\u003eSaracoglu S., Saygi K., Uluozlu O., Tuzen M., Soylak M. (2007). Determination of trace element contents of baby foods from Turkey. Food Chemistry, 105(1):280\u0026ndash;285. https://doi.org/10.1016/j.foodchem.2006.11.022\u003c/li\u003e\n\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"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":"Metallic trace elements, SAA, Migration, Tin can, Canned foods","lastPublishedDoi":"10.21203/rs.3.rs-7762159/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-7762159/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eThis study aimed to assess the migration of metallic trace elements (MTEs) from metallic food packaging to canned foods. Iron, zinc, copper, cadmium, and lead were determined in 52 canned foods samples (tomato paste and pineapple) marketed in Algiers. The determination was carried out by AAS after mineralization by wet acid digestion. The results highlighted that approximately 29% of the analyzed samples did not meet the regulatory limits, especially for Cd, with 11 samples (21%) exhibiting high levels (\u0026ge;\u0026thinsp;0.05 mg/Kg). Conversely, statistical results indicated that concentrations of Fe, Zn, Cu, and Pb were statistically below regulatory limits. The study identified a significant increase in Zn and Cu contents with decreasing pH. Fe content was positively correlated with the presence of oxygen in the headspace. Zn and Cd contents were positively correlated, and both were positively correlated with food/packaging contact time.\u003c/p\u003e","manuscriptTitle":"Evaluation of trace element contents in canned tomato paste and canned pineapple marketed in Algeria","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-10-30 10:14:30","doi":"10.21203/rs.3.rs-7762159/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":"9129f63f-9eff-4272-b805-729491d519ba","owner":[],"postedDate":"October 30th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2025-11-11T14:38:31+00:00","versionOfRecord":[],"versionCreatedAt":"2025-10-30 10:14:30","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-7762159","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-7762159","identity":"rs-7762159","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}