Ducruet V, Vitrac O, Saillard P, Guichard E, Feigenbaum A, Fournier N
INRA, Unité Mixte de Recherche SCALE, Massy CEDEX, France.
Food Addit Contam. 2007 Nov;24(11):1306-17. doi: 10.1080/02652030701361283.
The sorption of 14 aroma compounds into PET and PVC was monitored during storage of a strawberry syrup for 1 year. Concentrations in the syrup and in the polymer were determined during storage and compared with previously published results obtained with glass bottles. Apparent partition coefficients between the polymer and the syrup (noted K app) were estimated from experimental kinetics without reaching equilibrium K app values and optimally identified from the kinetic data obtained between 30 and 90 days. They exhibited a similar behaviour for both polymers with values were between 2 x 10(-5) and 2 x 10(-3), 4 x 10(-5) and 3 x 10(-2), respectively, for PET and PVC. The variation of K app values in PET was mainly correlated to the polarity of tested compounds as assessed by their log P values. By contrast, the variations in K app values for PVC were mainly related to their chain lengths. Due to slightly higher partition coefficients and diffusion coefficients in PVC compared with PET, the amount of absorbed aroma was four times higher in PVC than in PET; however, the amount of absorbed aroma compounds was less than 0.1% of the initial amount present into the syrup, except for octyl butanoate. The variation in concentration in the syrup was interpreted as a combination of a degradation process and a transport process into the packaging material. Both effects were particularly noticeable for both PET and unstable aroma compounds.
在草莓糖浆储存1年的过程中，监测了14种香气化合物在聚对苯二甲酸乙二酯（PET）和聚氯乙烯（PVC）中的吸附情况。在储存期间测定了糖浆和聚合物中的浓度，并与之前用玻璃瓶获得的已发表结果进行了比较。聚合物与糖浆之间的表观分配系数（记为K app）是根据未达到平衡K app值的实验动力学估算的，并从30至90天获得的动力学数据中进行了最佳识别。对于这两种聚合物，它们表现出相似的行为，PET和PVC的K app值分别在2×10⁻⁵至2×10⁻³、4×10⁻⁵至3×10⁻²之间。PET中K app值的变化主要与测试化合物的极性相关，这通过它们的log P值来评估。相比之下，PVC中K app值的变化主要与其链长有关。由于PVC中的分配系数和扩散系数略高于PET，PVC中吸收的香气量是PET中的四倍；然而，除丁酸辛酯外，吸收的香气化合物量不到糖浆中初始量的0.1%。糖浆中浓度的变化被解释为降解过程和向包装材料中传输过程的综合作用。对于PET和不稳定的香气化合物，这两种影响都尤为明显。
