In this work, inspired by the biological structure of shellfish, a bio-based bilayer smart packaging film was developed for real-time visual monitoring of meat freshness. Specifically, the bilayer smart packaging film consisted of a protective outer layer and a functional inner layer. The protective outer layer had a shell-like “brick and mortar” microstructure, consisting of a hard substance (mica powder) and a bio-based soft substance (polylactic acid), which provided the film with improved water resistance and gas barrier properties (WVP = 5.38–6.05 g·m−1·s−1·Pa−1). The functional inner layer consisted of a composite polysaccharide matrix (guar gum, sodium alginate and carboxylated cellulose nanofibers) and three natural indicators (black rice extract, curcumin and their composite indicator), which provided the film with enhanced light barrier property (T600: from 61.6 to 4.0 %), antioxidant capacity and pH-responsive property. Notably, this bilayer smart packaging film prepared by the shellfish bionic strategy demonstrated universal applicability of freshness monitoring for three typical meats (chicken, pork and shrimp). In brief, this work provides promising and feasible results based on an aquatic organism biomimetic strategy for the preparation of sustainable and high-performance bio-based smart packaging materials, which has potential applications in the field of food quality maintenance and food safety monitoring.

中文翻译：

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设计一种受贝类启发的生物基双层智能包装材料，具有增强的防水性和阻隔性能，用于普遍适用的肉类新鲜度监测


在这项工作中，受贝类生物结构的启发，开发了一种生物基双层智能包装膜，用于实时视觉监测肉类新鲜度。具体来说，双层智能包装膜由保护性外层和功能内层组成。保护外层具有贝壳状的“砖和砂浆”微观结构，由硬质物质（云母粉）和生物基软物质（聚乳酸）组成，这使薄膜具有更好的耐水性和气体阻隔性能（WVP = 5.38–6.05 g·m−1·s−1·Pa−1）。功能性内层由复合多糖基质（瓜尔豆胶、海藻酸钠和羧化纤维素纳米纤维）和三种天然指示剂（黑米提取物、姜黄素及其复合指示剂）组成，为薄膜提供了增强的光阻隔性能（T600：从 61.6 到 4.0%）、抗氧化能力和 pH 响应性能。值得注意的是，这种由贝类仿生策略制备的双层智能包装膜证明了新鲜度监测对三种典型肉类（鸡肉、猪肉和虾）的普遍适用性。简而言之，这项工作基于水生生物仿生策略为制备可持续和高性能的生物基智能包装材料提供了有前途且可行的结果，在食品质量维护和食品安全监测领域具有潜在的应用价值。