聚酰胺/聚丙烯蒸煮袋中2,4-二氨基甲苯和4,4’-二氨基二苯甲烷向酸性食品模拟物的迁移分析

采用液相色谱-三重四极杆串联质谱（liquid chromatography-triple quadrupole tandem mass spectrometry，LC-MS/MS）法，测定尼龙/聚丙烯（polyamide/cast polypropylene，PA/CPP）蒸煮袋中2 种初级芳香胺（primary aromatic amines，PAAs）物质2,4-二氨基甲苯（2,4-diaminotoluene，2,4-TDA）和4,4’-二氨基二苯甲烷（4,4’-diaminodiphenylmethane，4,4’-MDA）向4%乙酸食品模拟液的迁移量，并研究不同热处理及杀菌方式（巴氏杀菌、蒸、煮、高温灭菌、紫外杀菌）对蒸煮袋中这2 种物质向4%乙酸食品模拟物中迁移的影响。实验结果表明：LC-MS/MS检测2,4-TDA和4,4’-MDA迁移量的检出限均不大于0.02 μg/kg，定量限均不大于0.05 μg/kg，满足欧盟标准中对于PAAs限量的检测要求。在此基础上，研究发现除紫外杀菌对2,4-TDA和4,4’-MDA的迁移无显著影响外，巴氏杀菌、蒸、煮、高温灭菌均会促进PA/CPP蒸煮袋中2,4-TDA和4,4’-MDA向4%乙酸溶液的迁移，迁移量随着迁移温度的升高显著增加（P＜0.05）。根据迁移结果可知，在对蒸煮袋包装的食品进行杀菌处理时，紫外和巴氏杀菌是相对安全的处理方式；另外，在对蒸煮袋包装的食品进行加热时，相比煮，蒸是更为安全的一种加热方式。而在121 ℃高温灭菌15 min条件下，2 种PA/CPP样品袋中4,4’-MDA的迁移量分别达到2.733 μg/kg和3.113 μg/kg，均高于欧盟正在修订的对单个PAAs的迁移限量（0.002 mg/kg），具有潜在的食品安全风险。可见，当利用PA/CPP蒸煮袋包装食品时，不同热处理方式对胶黏剂中PAAs的迁移量及食品安全的影响值得重点关注。

Analysis of the Migration of 2,4-Diaminotoluene and 4,4’-Diaminodiphenylmethane from Polyamide/Polypropylene Retort Pouches to Acidic Food Simulants

Liquid chromatography-triple quadrupole tandem mass spectrometry (LC-MS/MS) was used to detect the migration of the primary aromatic amines 2,4-diaminotoluene (2,4-TDA) and 4,4’-diaminodiphenylmethane (4,4’-MDA) from polyamide/polypropylene (PA/CPP) retort pouches to acidic food simulants (4% acetic acid solution). In addition, different heat treatments and sterilization methods (pasteurization, steaming, boiling, high-temperature sterilization, and ultraviolet sterilization) were compared for their effects on the migration of both substances. The results showed that the limits of detection and the limits of quantifications for the migration of 2,4-TDA and 4,4’-MDA were both lower than 0.02 and 0.05 μg/kg, respectively, which meet the requirements of European Union standard for the limit of primary aromatic amines (PAAs). This study found that pasteurization, steaming, boiling, and high-temperature sterilization significantly promoted the migration of 2,4-TDA and 4,4’-MDA from PA/CPP retort pouches to 4% acetic acid solution in a temperature-dependent fashion (P < 0.05), which was not significantly affected by ultraviolet (UV) sterilization. According to the migration data, UV irradiation and pasteurization were relatively safe methods for the sterilization of foods packaged in retort pouches. In addition, steaming was a safer method than boiling for heating retort pouched foods. After 15 min of high-temperature sterilization at 121 ℃, the migration amounts of 4,4’-MDA from two commercial brands of PA/CPP retort pouches were 2.733 and 3.113 μg/kg, respectively, which were higher than the EU’s revision of the migration limit for individual PAAs (0.002 mg/kg) and could cause potential food safety risks. Hence, the impact of different heat treatment methods on the migration of PAAs from PA/CPP retort pouches and the safety of retort pouched foods is worthy of attention.