Migración global de sustancias no volátiles y migración específica de €-caprolactama fundas de poliamida 6 con iones Ag + -Zn ++ J. Food Sci. Gastron . (July - December 2023) 1(2): 1-6https://doi.org/10.5281/zenodo.13994642ISSN: 3073-1283 ORIGINAL ARTICLE Global migration of non-volatile substances and specific migration of €-caprolactam in polyamide 6 casings with Ag + -Zn ++ ions María I. Lantero mlantero@ifal.uh.cu1 Instituto de Ciencia y Tecnología Alimentaria (INTAL), Itagüí, Colombia.2 Instituto de Farmacia y Alimentos, Universidad de La Habana, La Habana, Cuba.Received: 06 February 2023 / Accepted: 17 May 2023 / Published online: 15 July 2023© The Author(s) 2023 Jairo H. Patiño 1 · Luis E. Henríquez 1 · María I. Lantero 2 Abstract Food packaging plays a key role in preserv-ing the quality and safety of meat products. In this context, packaging materials, such as polyamide casings, must com-ply with migration regulations that ensure food safety. This study evaluated the total migration of non-volatile substances and the specifc migration of the monomer ɛ-caprolactam in polyamide 6 casings used for meat products, with and with-out the addition of silver (Ag + ) and zinc (Zn ++ ) ions. Food simulants were used to represent real processing and storage conditions of sausages, applying total immersion, pouch, and cell. The results indicated that the global migration of the casings, both under control conditions and with additives, complied with international regulations (limits of 50-60 mg/ kg). Furthermore, the specifc migration of ɛ-caprolactam was below the regulatory limit (15 mg/kg), with no signif - cant diferences between casings with and without additives. The highest values were obtained with the ethanol (95%) simulant. Keywords polyamide 6, global migration, ɛ-caprolact -am, active packaging, food safety, food simulants. Resumen El envasado de alimentos desempeña un rol cla-ve en la preservación de la calidad y seguridad de los produc-tos cárnicos. En este contexto, los materiales de empaque, como las fundas de poliamida, deben cumplir con norma-tivas de migración que garantizan la inocuidad alimentaria. Este estudio evaluó la migración total de sustancias no volá- tiles y la migración específca del monómero ɛ-caprolactama en fundas de poliamida 6 utilizadas para embutidos cárnicos, con y sin la adición de iones plata (Ag + ) y zinc (Zn ++ ). Se utilizaron simulantes de alimentos para representar condicio-nes reales de procesamiento y almacenamiento de embuti-dos, aplicando métodos como inmersión total, bolsa y cel-da. Los resultados indicaron que la migración global de las fundas, tanto en las condiciones control como con aditivos, cumplió con las normativas internacionales (límites de 50-60 mg/kg). Además, la migración específca de ɛ-caprolactama fue menor al límite reglamentario (15 mg/kg), sin diferencias signifcativas entre las fundas con y sin aditivos. Los valores más altos se obtuvieron con el simulante etanol (95 %). Palabras clave poliamida 6, migración global, ɛ-caprolac -tama, envases activos, seguridad alimentaria, simulantes de alimentos. How to cite Patiño, J. P, Henríquez, L. E., & Lantero, M. I. (2023) Global migration of non-volatile substances and specifc migration of €-caprolactam in polyamide 6 casings with Ag+-Zn++ ions. Journal of Food Science and Gastronomy , 1 (2), 1-6. https://doi.org/10.5281/zenodo.13994642
J. Food Sci. Gastron . (July - December 2023) 1(2): 1-6 2 Introduction Packaging plays a fundamental role in the food chain. Among its many functions, the most important is maintai-ning or enhancing the quality and safety of food. Since the end of the last century, new technologies have been develo-ped that improve the properties of packaging materials and systems, increasing the positive interactions between food and packaging (Pocas et al., 2011; Zigoura & Pascal, 2011; Brody, 2012).The areas of packaging evolution have been primarily focused on the development of new packaging techniques (López-Rubio et al., 2006; Catalá & Gavara, 2011); the use of gases or materials mainly centered on analyzing possible interactions between food and packaging materials; adapta-tion to new preservation techniques (irradiation, non-thermal treatments such as high pressure, light pulses, etc.); innova-tion in packaging design, due to the diversity of products on the market, such as “reusable” packaging (Lagaron, 2006; Gavara et al., 2011); and studies on recycling and the envi- ronmental impact of diferent types of packaging (Ariosti et al., 2010).Traditional packaging materials are derived from petro-leum and pose health risks associated with migrating hazar-dous compounds. Thus, it is desirable to develop packaging capable of integrating shelf life, safety, and the retention of bioactive substances without causing major alterations in the migration rate of compounds in the packaging food system (AIMPLAS, 2008). The migration of substances from pac-kaging to food is a fundamental aspect of food safety. This process involves the transfer of compounds such as mono-mers, plasticizers, and antioxidants from the packaging to the food under storage or processing conditions, afecting product quality and consumer health (Sablani et al., 2020). Migration is infuenced by both the properties of the food and the characteristics of the packaging, making it a techni-cal and regulatory challenge (Ariosti, 2011). There are two types of migration: global and specifc. Global migration refers to the total amount of substances transferred from the packaging to the food under normal use conditions or laboratory simulation, without considering the chemical nature of the migrated compounds (Helmroth et al., 2002). In contrast, specifc migration refers to the amount of a particular substance of toxicological interest that migrates into the food. This type of migration is key to regulating po-tentially hazardous compounds, such as plasticizers, whose limits are established in regulations (Alamri et al., 2021).International regulations, such as the European Union’s Directive 2002/72/EC, set clear limits for global and specifc migration to protect consumer health. These legislations de- fne positive lists of substances permitted in packaging ma -nufacturing and stipulate the necessary analytical methods to ensure compliance with migration limits, both quantitatively and qualitatively. In recent years, there have been signifcant advances in the development of active packaging, which not only prevents the undesirable migration of compounds but also provides additional functionalities, such as antimicrobial capabilities. Examples include packaging that incorporates silver (Ag + ) and zinc (Zn ++ ) ions, which have demonstrated antimicrobial properties that extend the shelf life of food without compro-mising food safety (Patiño et al., 2014; Patiño et al., 2022). This regulatory and scientifc framework regarding the migration of substances from plastic materials into food hi-ghlights the need to continue developing robust analytical methods and innovative packaging that not only comply with safety limits but also ofer additional benefts in terms of food preservation and quality. Therefore, the objective of this work was to determine the sanitary suitability of polya- mide 6 flm with and without the addition of Ag + -Zn ++ ions, through global migration of non-volatile substances and spe- cifc migration of ε-caprolactam. Materials and methods The flms were obtained at the ALICO S.A. flm plant (Medellín, Colombia) using proprietary technology, through a tubular blown flm extrusion process, which consists of a blowing system with a circular die and a fat lip. Its stages involve the plasticization of the raw material, which is pre-sented in the form of granules or powder, the introduction of the plasticized product into a mold that shapes it into the desired form (cylinder), solidifcation, and winding into rolls or cutting into units. The extrusion conditions are tempera-ture of 130 °C, pressure of 14,000 kPa, a draw speed of 2.5, and a time of 3 minutes. The flms have a layer distribution of PA/adhesive/PE-pigment/adhesive/PA from outside to in- side (Alifex, ALICO S.A.).The flms containing Ag + and Zn ++ ions (TA) were ob-tained by modifying the previous technology, by adding 3% (m/m) of the antimicrobial product (IRGAGUARD® B7000, CIBA) to the inner layer, which was added with the plasticizer (Ultramid®, BASF Corporation) to ensure homo- geneous dispersion. The flms made according to conventio -nal technology (without the addition of Ag + and Zn ++ ions) were identifed as control flm (TP). The global migration of non-volatile substances from the packaging to food simulants (A: distilled water; B: 3% (m/v) glacial acetic acid in aqueous solution; D: absolute ethanol 95% (v/v) in aqueous solution) was determined according to the criteria and guidelines outlined in Resolutions 683 and 4143 (MSPS-Colombia, 2012), Directives 85/572, 82/711, and 97/48 (EU Regulation No. 10, 2011), FDA (1995), FDA (2000), and FSA (2010).
J. Food Sci. Gastron . (July - December 2023) 1(2): 1-6 3 Reference methods applied included total immersion con-tact; pouch and cell, where 1 dm² of the sample was exposed to 100 mL of each simulant, followed by conditioning for 2.5 hours at 60 °C, and then 10 days at 40 °C, simulatin g the conditions that the meat product would experience during production, processing, and prolonged storage. After condi-tioning, the residues obtained were evaporated in a porcelain capsule at a controlled temperature until a constant weight was achieved. In determining the specifc migration of ε-caprolactam, the same conditions of time, temperature, and simulants used for determining global migration were applied. After conditio-ning (2.5 hours at 60 °C, followed by 10 days at 40 °C), methylation and extraction were performed using methanol/sulfuric acid and immersion in hexane; a second extraction with 20 mL of hexane for 20 minutes, followed by dilution with 10 mL of ACN (v/v) with centrifugation, and fnally, an aliquot was taken for analysis by GC-FID-Capillary of the specifc compound ε-caprolactam. The values of the evaluated indicators were analyzed us- ing analysis of variance (ANOVA) with Statistics software (version 7, 2004, StatSoft Inc., Tulsa, USA). To identify sta- tistically signifcant diferences between samples, Duncan’s multiple range test was applied with a signifcance level of p ≤0.05. Results and discussion Table 6 shows the mean values and standard deviations obtained from the global migration test, understood as a me-asure of the inertia to transfer non-volatile substances from the flms (TP) and (TA) to the simulants A, B, and D (Catalá, 2012; Sendón, 2005).The addition of Ag + and Zn ++ ions did not signifcantly in -crease ( p ≤0.05) the values of global migration compared to the control in the three evaluated methods. The global mi-gration values were higher for simulant D (absolute ethanol 95%), followed by B (3% glacial acetic acid), and to a lesser extent A, due to their extractive power characteristics. The ease with which these migrating components pass through the polymer molecules largely depends on proper-ties of these substances, such as initial concentration, com-patibility, size, and molecular structure (Rardniyom, 2008), as well as the thermodynamic properties of the polymer, in-cluding its polarity, solubility, density, crystallinity, degree of crosslinking, and branching, among others, all of which play a fundamental role in the interaction between the difer -ent parts of this system (Catalá, 2012). These migration pro- cesses are accelerated by the efect of temperature involved in simulating the actual conditions of use of the packaging, increasing the fexibility of the polymer molecules (Zigoura & Pascal, 2007). Table 1. Global migration from flms TP and TA in simulants A, B, and D SimulantCasingMethodGlobal migration (mg/kg) ATPTotal immersion2,7 (0,7) bPouch2,3 (1,1) bCell3,1 (1,8) aTATotal immersion3,9 (1,0) aPouch4,0 (2,3) aCell3,4 (1,2) aBTPTotal immersion4,4 (0,6) aPouch4,1 (0,9) aCell4,0 (1,7) aTATotal immersion4,4 (1,0) aPouch4,3 (0,9) aCell4,3 (1,4) aDTPTotal immersion6,6 (0,4) aPouch6,2 (1,7) aCell7,1 (2,4) aTATotal immersion7,2 (1,3) aPouch6,0 (0,7) aCell7,3 (1,5) a Mean (standard deviation); n = 3. TP: control flms; TA: flms with the addition of Ag + and Zn ++ ions.Simulants A: distilled water; B: 3% (m/v) glacial acetic acid in aqueous solution; D: absolute ethanol 95% (v/v) in aqueous solution.
J. Food Sci. Gastron . (July - December 2023) 1(2): 1-6 4 The global migration values for both flms in the tested si -mulants and in the three methods ranged from 2.7 to 7.3 mg/kg, complying with the global migration limits established by various regulations: Colombian legislation (50 mg/kg - Resolution 834/13); Mercosur (50 mg/kg - GMC Resolution No. 12/10); FDA (50 mg/kg - Section 177.1520); and the Regulation by the European Commission (60 mg/kg - Regu-lation 10/11) (Grob et al., 2007). Figure 1 presents the migration of the monomer ε-capro -lactam, a compound of toxicological interest and high mole-cular weight resulting from the polymerization of polyami- des (PA-6) (Osváth et al., 2020) over 30 days.The partition and difusion coefcients for TP and TA in simulants A and D are presented in Table 2. For both simulants, A and D, and types of flm (TP and TA), the results obtained remained within a similar range due to the solubility of the monomer ε-caprolactam in water and 95% ethanol under the test conditions (Stofers et al., 2005).The highest migration value of ε-caprolactam at 30 days was reached in simulant D (95% ethanol), resulting in 6.20 mg/kg for the flm with the addition of Ag + and Zn ++ ions, with no signifcant diference compared to the flm without ion addition under the same conditions. The results do not exceed the migration limits established by current legislation (15 mg/kg - Resolution No. 105, 1999) and the European Commission Directive 2002/72/EEC.Song et al. (2018) produced PA 6 sheets using a twin-screw extruder to evaluate their safety. Migration concentrations of caprolactam from the PA 6 sheets to food simulants were as-sessed according to the standard migration testing conditions of the Korean Food Standards Code (KFSC). The concentra-tions were investigated in various food simulants (distilled water, 4% acetic acid, 20 and 50% ethanol, and heptane) and under storage conditions (25, 60, and 95 °C). The migration concentrations of caprolactam in the food simulants were de-termined as follows: 4% acetic acid (0.982 mg/L), distilled Figure 1. Migration of ε-caprolactam from control flms (TP) and flms with the addition of Ag + and Zn ++ ions (TA) in simu-lants A (a) and D (b). Table 2. Difusion and partition coefcients of the migration of ε-caprolactam in simulants A and D SimulantFilm Difusion coefcientPartition coefcient ATP0.07680.0008TA0.08560.0014DTP0.06880.0200TA0.08190.0196 Simulant A: water; simulant D: absolute ethanol 95% (v/v) in aqueous solution.
J. Food Sci. Gastron . (July - December 2023) 1(2): 1-6 5 water (0.851 mg/L), 50% ethanol (0.624 mg/L), 20% ethanol (0.328 mg/L), and n-heptane (not detected). The migrations were below the regulatory concentration (15 mg/L) accor-ding to the KFSC testing conditions. Together, these results confrmed that the KFSC standard migration testing condi -tions are reliable for assessing the safety of PA 6. Conclusions Adding Ag + and Zn ++ ions did not signifcantly increase global migration or the specifc migration of ε-caprolactam compared to flms without additives. The results obtained comply with the limits established by international regula- tions, demonstrating that the use of these flms is safe for contact with processed meat products. However, the ethanol simulant (95%) showed a greater extractive capacity, high-lighting the importance of appropriately selecting simulants when evaluating migration in diferent types of food. References AIMPLAS. Instituto Tecnológico del Plástico. 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J. Food Sci. Gastron . (July - December 2023) 1(2): 1-6 6 Stofers, E.C., Sulof, J.E., Marcy, J.E., Blakistone, B.A., Duncan, S.E., Long, T.E., & O’Keefe, S.F. (2005). Sorption behavior of selected aldehyde-scavenging agents in poly(ethylene terephthalate) blends. Jour-nal of Food Science, 68 (6), 2028-2033. https://doi.org/10.1111/j.1365-2621.2003.tb10188.xZigoura, L., & Pascal, M. (2011). Active, controlled and in-telligent packaging market set to soar. Plastics Additi-ves & Compounding, May/June . Conficts of interest The authors declare that they have no conficts of interest. Author contributions Jairo H. Patiño, Luis E. Henríquez and María I. Lantero: Conceptualization, data curation, formal analysis, investi-gation, methodology, supervision, validation, visualization, drafting the original manuscript and writing, review, and editing. Data availability statement The datasets used and/or analyzed during the current study are available from the corresponding author on reasonable request. Statement on the use of AI The authors acknowledge the use of generative AI and AI-assisted technologies to improve the readability and cla-rity of the article. Disclaimer/Editor’s note The statements, opinions, and data contained in all publi-cations are solely those of the individual authors and contri-butors and not of Journal of Food Science and Gastronomy.Journal of Food Science and Gastronomy and/or the edi-tors disclaim any responsibility for any injury to people or property resulting from any ideas, methods, instructions, or products mentioned in the content.