聚乳酸抗菌包装中麝香草酚在食品模拟物中迁移规律

摘要

研究麝香草酚/聚乳酸包装材料中的抗菌剂麝香草酚在食品模拟物中的迁移行为.在4、10、20、30 ℃条件下分别将麝香草酚/聚乳酸包装材料浸入蒸馏水溶液、体积分数4%乙酸溶液、正己烷溶液、体积分数10%乙醇溶液中,通过紫外分光光度法测定食品模拟液中麝香草酚迁移量,分析温度和食品模拟物对麝香草酚迁移量的影响,在实验数据基础上,采用Piringer方程建立麝香草酚迁移模型,分析验证迁移模型的合理性.结果表明:麝香草酚迁移量随着迁移温度升高和迁移时间延长而逐渐上升直至平衡,且在4 种食品模拟物中麝香草酚的迁移量大小顺序为:正己烷>10%乙醇>4%乙酸>蒸馏水;根据幂律方程发现麝香草酚的迁移机制符合Fick扩散定律,且迁移方程扩散系数随迁移温度升高而增大,分配系数与之相反;Piringer方程能够较好地描述麝香草酚迁移行为.在迁移实验的基础上构建数学模型,进一步完善基于聚乳酸食品包装材料的迁移理论,以期更好地预测食品包装中麝香草酚的迁移.%The migration behavior of thymol from polylactic acid (PLA) film to different food stimulants was studied by soaking the film in distilled water, 4% acetic acid (V/V), n-hexane and 10% ethanol (V/V) at 4, 10, 20 and 30 ℃, respectively. The migration amount of thymol to food simulants was determined by UV spectrophotometry. The effects of temperature and food simulants on the migration of thymol were analyzed. Based on the obtained experimental data, a model for thymol migration was established by the Piringer equation and its rationality was analyzed. Results showed that the thymol content increased gradually until reaching equilibrium with increasing migration temperature and time in both simulants. The migration of thymol to four food simulants was in the decreasing order of n-hexane > 10% ethanol > 4% acetic acid >distilled water. According to the power law model, the mechanism of thymol diffusion through PLA films was in line with Fick's law. The diffusion coefficient increased with migration temperature while the opposite was observed for the partition coefficient. Thus, the Piringer equation could describe the migration behavior of thymol. The mathematical equation developed in this study can provide a useful tool for prediction of the migration of thymol from PLA food packaging materials to foodstuffs.