Time temperature indicator

Abstract: A systematic approach that allows the correlation of the response of a Time-Temperature Indicator (TTI) to the consumed and remaining shelf life of a food product exposed to the same variable temperature conditions was developed. The approach was based on kinetic principles and is applicable to a TTI-food system without necessitating side by side testing. The applicability of three major TTI types to the developed scheme was studied. Experiments under several isothermal conditions were conducted and kinetic parameters for the three TTI were determined. All TTI showed an Arrhenius temperature dependence and their calculated activation energies ranged from 10 to 40 kcal/mol.

Abstract: Food safety is a constant concern for humans. Besides adulteration and contamination, another major threat comes from the spontaneous spoilage of perishable products, which is basically inevitable and highly dependent on the temperature history during the custody chain. For advanced quality control and assessment, time–temperature indicators (TTIs) can be deployed to document the temperature history. However, the use of TTIs is currently limited by either relatively high cost or poor programmability. Here we describe a general, kinetically programmable, and cost-efficient TTI protocol constructed from plasmonic nanocrystals. We present proof-of-principle demonstrations that our TTI can be specifically tailored and thus used to track perishables, dynamically mimic the deteriorative processes therein, and indicate product quality through sharp-contrast multicolor changes. The flexible programmability of our TTI, combined with its substantially low cost and low toxicity, promises a general applicability to e...