Department of Life and Food Sciences Weihenstephan, Technical University of Munich, Freising, Germany; Fraunhofer Institute for Process Engineering and Packaging, Freising, Germany.
Department of Life and Food Sciences Weihenstephan, Technical University of Munich, Freising, Germany; Fraunhofer Institute for Process Engineering and Packaging, Freising, Germany.
Food Microbiol. 2021 Jun;96:103725. doi: 10.1016/j.fm.2020.103725. Epub 2021 Jan 4.
Food packaging films were coated with polyvinyl acetate (PVA) containing different concentrations of citral or Litsea (L.) cubeba essential oil (EO). Antimicrobial contact trials in style of ISO22916 were performed. Citral coatings achieved bactericidal effects against Escherichia coli (2.1 log) and Staphylococcus aureus (4.3 log) at concentrations of 20%. L. cubeba inactivated more than 4 log cycles of both bacteria at a concentration of 20%. To determine the antimicrobial activity across the gas phase, a unique method for volatile agents was developed, adapting ISO22196. GC/MS measurements were performed to supplement microbiological tests in a model packaging system with a defined 220 ml headspace (HS). HS-equilibrium concentrations of 1.8 μg/ml were found for 20%citral-coatings, resulting in antimicrobial effects of 3.8 log against of E. coli. Saccharomyces cerevisiae (4.74 log) and Aspergillus niger (4.29 log) were more effectively inactivated by 3% and 5% coatings. In an application trial with strawberries, simulating a headspace packaging, growth inhibitory effects on the yeast and mold microbiota were found for the 20% coatings.
食品包装薄膜涂有不同浓度的柠檬醛或山苍子（Litsea）精油（EO）的聚醋酸乙烯酯（PVA）。采用 ISO22916 风格进行了抗菌接触试验。在 20%的浓度下，柠檬醛涂层对大肠杆菌（2.1 对数）和金黄色葡萄球菌（4.3 对数）具有杀菌作用。山苍子在 20%的浓度下可使两种细菌失活超过 4 个对数循环。为了确定气相中的抗菌活性，开发了一种针对挥发性物质的独特方法，该方法适用于 ISO22196。在具有定义的 220 毫升顶空（HS）的模型包装系统中，进行了 GC/MS 测量以补充微生物测试。在顶空平衡浓度为 1.8 μg/ml 的情况下，发现 20%的柠檬醛涂层对大肠杆菌具有 3.8 对数的抗菌作用。3%和 5%的涂层对酿酒酵母（Saccharomyces cerevisiae）（4.74 对数）和黑曲霉（Aspergillus niger）（4.29 对数）的灭活效果更有效。在草莓的应用试验中，模拟顶空包装，发现 20%的涂层对酵母和霉菌微生物区系有生长抑制作用。
