Reliability of Time‐Temperature Indicators as Food Quality Monitors Under Nonisothermal Conditions

Application of time temperature indicators (TTI) is based on response information or kinetic models from isothermal testing. The reliability of such models under variable temperature conditions was systematically studied. Nonisothermal experiments of two types were conducted involving prolonged exposures to high temperatures followed by storage at low temperatures to study the “history effect,” and storage at controlled, sinusoidaly varying temperatures. Three major types of commercial TTI were studied. Results showed that, although some types of TTI exhibit a significant “history effect,” the prediction models can be applied satisfactorily for the variable temperature storage.