随着食品包装的发展,消费者利益正在从传统食品包装系统转向智能食品包装系统。智能包装包括以消费者可感知的视觉或交互形式显示变化的活性组分。这提供了对包装食品的质量和保质期的实时监控,并提高了透明度。例如,pH敏感的基于天然色素的薄膜会根据pH水平的变化而改变颜色,使薄膜/标签能够反映包装内食物的酸度或碱度的变化。像花青素这样的天然色素,姜黄素,betalains,叶绿素,和类胡萝卜素已被全面报道用于开发可生物降解的淀粉pH敏感膜,蛋白质,壳聚糖,和纤维素。天然颜料提供与这些生物聚合物的良好相容性并改善膜的其他性能参数。然而,这些薄膜仍然缺乏石油基合成塑料薄膜的强度和多功能性。但是这些薄膜可以用作指示器,并与初级包装结合使用,以监测新鲜度,时间-温度,和肌肉食物的泄漏,乳制品,水果和蔬菜,和烘焙产品。因此,这篇综述提供了pH敏感色素的详细概述,它们与天然聚合物的相容性,他们在电影表演中的角色,以及他们的食品包装应用。
As food packaging evolves, consumer interests are shifting from traditional to intelligent food packaging systems. Intelligent packaging includes active components that display changes in a visual or interactive form perceivable by consumers. This offers real-time monitoring of the quality and shelf life of the packaged food and enhances transparency. For example, pH-sensitive natural pigment-based films change color in response to variations in pH levels, enabling the film/labels to reflect alterations in the acidity or basicity of the food inside the package. Natural pigments like anthocyanins, curcumin, betalains, chlorophyll, and carotenoids have been comprehensively reported for developing biodegradable pH-sensitive films of starch, protein, chitosan, and cellulose. Natural pigments offer great compatibility with these biopolymers and improve the other performance parameters of the films. However, these films still lack the strength and versatility of petroleum-based synthetic plastic films. But these films can be used as an indicator and combined with primary packaging to monitor freshness, time-temperature, and leak for muscle foods, dairy products, fruits and vegetables, and bakery products. Therefore, this review provides a detailed overview of pH-sensitive pigments, their compatibility with natural polymers, their role in film performance in monitoring, and their food packaging applications.