Student Research Committee, Tabriz University of Medical Sciences, Tabriz 5166614711, Iran.
Nutrition Research Center, Department of Food Science and Technology, Faculty of Nutrition and Food Sciences, Tabriz University of Medical Sciences, Tabriz 516615731, Iran.
Molecules. 2022 May 16;27(10):3168. doi: 10.3390/molecules27103168.
Nanocomposite biopolymer materials containing colorimetric pH-responsive indicators were prepared from gelatin and chitosan nanofibers. Plant-based extracts from barberry and saffron, which both contained anthocyanins, were used as pH indicators. Incorporation of the anthocyanins into the biopolymer films increased their mechanical, water-barrier, and light-screening properties. Infrared spectroscopy and scanning electron microscopy analysis indicated that a uniform biopolymer matrix was formed, with the anthocyanins distributed evenly throughout them. The anthocyanins in the composite films changed color in response to alterations in pH or ammonia gas levels, which was used to monitor changes in the freshness of packaged fish during storage. The anthocyanins also exhibited antioxidant and antimicrobial activity, which meant that they could also be used to slow down the degradation of the fish. Thus, natural anthocyanins could be used as both freshness indicators and preservatives in biopolymer-based nanocomposite packaging materials. These novel materials may therefore be useful alternatives to synthetic plastics for some food packaging applications, thereby improving the environmental friendliness and sustainability of the food supply.
含比色 pH 响应指示剂的纳米复合生物聚合物材料由明胶和壳聚糖纳米纤维制备而成。作为 pH 指示剂，使用了含有花青素的小檗和藏红花等植物提取物。花青素的掺入增加了生物聚合物薄膜的机械强度、阻隔水和光屏蔽性能。红外光谱和扫描电子显微镜分析表明，形成了均匀的生物聚合物基质，花青素均匀分布在其中。复合薄膜中的花青素可响应 pH 值或氨气水平的变化而变色，可用于监测储存过程中包装鱼的新鲜度变化。花青素还具有抗氧化和抗菌活性，这意味着它们也可用于减缓鱼的降解。因此，天然花青素可用作生物聚合物基纳米复合材料包装材料中的新鲜度指示剂和防腐剂。这些新型材料可能是一些食品包装应用中合成塑料的有用替代品，从而提高食品供应的环境友好性和可持续性。
