Review of Time Temperature Indicators as Quality Monitors in Food Packaging

Time temperature indicators (TTIs) are devices used for recording thermal history and indicating the remaining shelf life of perishable products throughout their storage, distribution and consumption. This is achieved by the irreversible change of colour resulting from the cumulative effects of time and temperature. When applied in intelligent packaging, TTI can provide visual information that is easily accessible, and thus, consumers can judge from the visual information whether the food has deteriorated, which helps to assure the quality and safety of food. TTI can be classified into several different groups including chemical TTI, physical TTI, biological TTI, and other new types of TTI based upon different principles of colour change. Although these kinds of TTI can basically provide effective information about food quality, there are still a number of problems with them in the food supply chain, such as migration of toxic substances, the inaccuracy of temperature monitoring and the high cost in the area of commercial application. However, there are also some scientific methods to solve the aforementioned problems of TTI. In this paper, the latest research of TTI is summarized, its status and its main problems are elaborated and the prospect of its development is envisaged, aiming to provide reference and support for researchers in this realm. Copyright (C) 2015 John Wiley & Sons, Ltd.