热力学数学模型对塑料中化学物向食品模拟液中迁移平衡时分配系数的预测研究

目的分配系数能够直接反映出塑料包装材料中有害化学物向食品迁移的水平,研究分配系数与塑料包装材料、迁移物及食品(模拟物)三者之间的关系有重要意义。方法以Scatchard-Hildebrand统计热力学理论为基础,从热力学平衡角度分析了化学物在包装材料/食品体系中的迁移和分配过程,建立了一个预测化学物迁移平衡时分配系数的热力学数学模型。通过所建立的初级数学模型对聚乙烯薄膜中四种抗氧化剂,即2,6-二叔丁基-4-甲基苯酚(BHT)、二丁基羟基茴香醚(BHA)、Irganox1010和Irganox1076向脂肪类食品模拟物异辛烷迁移平衡时状态进行模拟计算,并与已公开发表的实验数据进行了对比。结果聚乙烯薄膜中四种抗氧剂向异辛烷中迁移平衡的分配系数模拟值与实验值随温度变化趋势一致。结论该热力学模型符合迁移理论,对PE/抗氧剂/脂肪类食品体系分配系数的预测有一定的适用性。

Study of predicting equilibrium partition coefficient of migrants in food simulants from plastic by thermodynamic mathematical modeling

ABSTRACT: Objective Partition coefficient can reflect directly the migration level of the compounds from plastic package materials to food, to study the relationship between the partition coefficient and plastic materials, the migrates and the food(simulant). Methods Being based on the Scatchard-Hildebrand statistical thermodynamic theory, the processes of the compounds migrate and distribute in packaging material/food system were analyzed, and a thermodynamic mathematical model which can predict the equilibrium partition coefficient of migrants was established. The state of migration balance of four antioxidants (2,6-di-tert-butyl-4- methyl phenol, dibutyl hydroxyl anisole, Irganox 1010 and Irganox 1076) from PE to isooctane was simulated through the mathematical model, and the values were compared with the published experimental data. Results The trends with temperature of the simulate partition coefficients of four antioxidants in PE migrate to isooctane are consistent with the experimental values. Conclusion The thermodynamic model is in line with the migration theory, and is available for predicting the partition coefficients of the PE/antioxidant/ fatty food system.