Application Progress of pH-sensitive Materials in Smart Food Packaging

With the increasing awareness of food safety among consumers, the visual judgment of food quality through packaging color change has become a new demand, therefore, smart packaging has become a common concern of academia and industry in recent years. pH-sensitive materials mixed with different polymers to obtain food packaging films that display different colors under different pH conditions have the real-time monitoring of the freshness of meat, shrimp, milk and other foods effect. This paper introduces two major pH-sensitive indicators, chemical chromophores and natural pigment chromophores, and classifies the color change mechanism of natural food pigments such as anthocyanin, curcumin, alizarin, cometin and betaine at different pH values, and summarizes the research progress, application status and research trends of pH-sensitive materials modified by blending with different polymers in the field of food packaging, in order to prepare a good performance, green and environmentally friendly. It provides a reference for the preparation of good performance and green food packaging.