Time-Temperature Indicators as Intelligent Packaging Features in the Food Industry: Types, Operation Mechanisms and Applications

Nowadays, with the increasing consumer awareness and tendency to use safe food products, the food producers consider using novel packaging systems more than ever. Intelligent packaging is one of the novel packaging systems that informs the consumer about the freshness and quality of packaged food by gathering and presenting information from inside and outside the food package. Time-temperature indicators are one type of intelligent packaging systems which are used when special temperature conditions are required for food preservation. The transport and supply of meat and dairy products need the cold-chain supply. Time-temperature indicators are able to report the application of cold-chain during the transportation and sale of such food products. There are different types of time-temperature indicators and each of them operates with different mechanisms. In this review paper, various types of time-temperature indicators have been introduced and their operation mechanism as well as their application as intelligent packaging of different foods has been discussed.