Abstract The incorporation of lactic acid bacteria (LAB) in edible films and coatings has recently emerged as an innovative strategy to provide packaging films with new functionalities in order to ensure food quality and safety. In this work, bioactive films were made by incorporating Lactococcus lactis subsp. lactis in cast polyvinyl alcohol (PVOH) matrices, alone or blended with a small percentage of proteins, protein hydrolysates, or yeast extract, and the effect of incorporating them on the morphology and optical properties of the PVOH films was studied. Moreover, the viability of L. lactis in the films developed stored at 20 °C and 43.2% relative humidity for four weeks, and the antimicrobial activity against L. monocytogenes were determined. The thickness, color properties, and morphology of the films incorporating LAB and nutrients did not show significant differences compared with plain PVOH films, but moisture content increased slightly with nutrient incorporation. L. lactis remained viable for 4 weeks of storage, but viability depended on the matrix composition, being lower in plain PVOH films and higher in films supplemented with proteins, hydrolysates, or yeast extract. The highest antimicrobial activity was observed in PVOH matrices with hydrolyzed gelatin or casein, and the lowest in plain PVOH films. The growth of L. lactis was similar in all the films after incubation in contact with L. monocytogenes at 37 °C in liquid medium, regardless of the initial concentration. The films developed could be applied in the design of food packages with the purpose of inhibiting growth of L. monocytogenes.

中文翻译：

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嵌入乳酸乳球菌亚种的基于 PVOH 的薄膜的抗感染特性。乳酸菌

摘要 在可食用薄膜和涂层中加入乳酸菌 (LAB) 是最近出现的一种创新策略，可为包装薄膜提供新的功能，以确保食品质量和安全。在这项工作中，生物活性薄膜是通过加入乳酸乳球菌亚种制成的。研究了浇铸聚乙烯醇 (PVOH) 基质中的乳酸，单独或与少量蛋白质、蛋白质水解物或酵母提取物混合，并研究了将它们掺入对 PVOH 膜的形态和光学特性的影响。此外，在 20 °C 和 43.2% 相对湿度下储存 4 周后，L.lactis 在开发的薄膜中的生存能力，并确定了对单核细胞增生李斯特氏菌的抗菌活性。厚度、颜色特性、与普通 PVOH 薄膜相比，加入 LAB 和营养物质的薄膜的形态和形态没有显示出显着差异，但随着营养物质的加入，水分含量略有增加。L. 乳酸菌在 ​​4 周的储存中保持活力，但活力取决于基质组成，在普通 PVOH 薄膜中较低，在补充有蛋白质、水解物或酵母提取物的薄膜中较高。在含有水解明胶或酪蛋白的 PVOH 基质中观察到最高的抗菌活性，而在普通 PVOH 薄膜中最低。无论初始浓度如何，在 37 °C 的液体培养基中与单核细胞增生李斯特菌接触孵育后，乳酸乳球菌的生长在所有薄膜中均相似。开发的薄膜可用于食品包装设计，目的是抑制单核细胞增生李斯特氏菌的生长。