Abstract

Recently, the research on intelligent packaging is gaining momentum, primarily being driven by consumer preferences to food safety and reducing the resource waste. Freshness indicator is a kind of simple and efficient intelligent packaging technology, which can directly and scientifically indicate the freshness of food without complex operation. Freshness indicator shows great potential in the food supply chain. As an innovative food packaging method, freshness indicator can effectively monitor food freshness in real time without damaging food and packaging. The objective of this review is to provide relevant information on freshness indicators, such as release of food freshness indicators (carbon dioxide volatile salt-nitrogen sulfides, etc.), types (chemical chromogenic formulation, data carrier indicator, natural color formulation), safety assessment methods (toxicological assessment, exposure assessment), barriers and trends. The potential of freshness indicators in the detection of perishable food freshness was emphasized. The applications of some freshness indicator products in food and the research demands of safety were also discussed.