Abstract: Time-temperature indicators (TTI) are smart labels designed to indicate the shelf life of foods. The match between TTI and objects to be detected is critical for its application. The optimal fitting model between TTI and objects to be detected varies with different reaction mechanisms between them. In the traditional matching process, unified models and parameters are often used, reducing the goodness of fit of the models. In this study, a contour-based TTI matching method having good model compatibility is proposed based on the equivalent transformation of quality changes at a certain time interval at different temperatures. The TTI matching method’s general applicability for various chemical kinetic models and microbial growth models is confirmed by formula derivation. These models are successfully combined, forming a multi-model matching method. Besides, the stability of equivalent transition ratio (ETR) and the feasibility of the multi-model matching method are validated based on chemical reactions in the changing process of the firmness of Muscat grapes and microbial growth in tilapia. These results will help with multi-model matching of TTI with different working mechanisms based on various chemical kinetic models and microbial growth models in a simple and intuitive manner, which will promote the application and popularization of TTI.

Key words: time-temperature indicators; chemical reaction; microbial growth; equivalent transition ratio; multi-model matching