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Abstract：
Absorption of hop volatiles by crown cork liner polymers and can coatings was investigated in beer during storage. All hop volatiles measured were prone to migrate into the closures, and the absorption kinetics was demonstrated to fit Fick\'s second law of diffusion well for a plane sheet. The extent and rate of diffusion were significantly dissimilar and were greatly dependent upon the nature of the volatile. Diffusion coefficients ranged from 1.32 × 10(-5) cm(2)/day (limonene) to 0.26 × 10(-5) cm(2)/day (α-humulene). The maximum amounts absorbed into the material at equilibrium were in the following order: limonene > α-humulene > trans-caryophyllene > myrcene ≫ linalool > α-terpineol > geraniol. With the application of low-density polyethylene (LDPE) liners with oxygen-scavenging functionality, oxygen-barrier liners made up from high-density polyethylene (HDPE) or liner polymers from a different manufacturer had no significant effect on the composition of hop volatiles in beers after prolonged storage of 55 days; however, significantly higher amounts of myrcene and limonene were found in the oxygen-barrier-type crown cork, while all other closures behaved similarly. Can coatings were demonstrated to absorb hop volatiles in a similar pattern as crown corks but to a lesser extent. Consequently, significantly higher percentages of myrcene were found in the beers.
摘要：
研究了啤酒储存过程中冠状软木衬里聚合物和罐头涂层对啤酒花挥发物的吸收。测得的所有啤酒花挥发物都容易迁移到封闭物中，并证明了吸收动力学很好地符合Fick的扩散第二定律。扩散的程度和速率明显不同，并且在很大程度上取决于挥发物的性质。扩散系数范围为1.32×10（-5）cm（2）/天（柠檬烯）至0.26×10（-5）cm（2）/天（α-腐烯）。在平衡时吸收到材料中的最大量按以下顺序：柠檬烯>α-腐植烯>反式-石竹烯>月桂烯芳樟醇>α-松油醇>香叶醇。随着具有除氧功能的低密度聚乙烯（LDPE）衬里的应用，由高密度聚乙烯（HDPE）或来自不同制造商的衬里聚合物制成的氧气阻隔衬里在延长55天后对啤酒中啤酒花挥发物的组成没有显着影响；但是，在氧气屏障型冠状软木中发现了更大量的月桂烯和柠檬烯，而所有其他闭包的行为类似。罐装涂料被证明以与冠状软木塞相似的方式吸收啤酒花挥发物，但程度较低。因此,在啤酒中发现了更高的月桂烯百分比。
