Preliminary study on time-temperature indicator (TTI) system based on urease

Time-temperature indicator (TTI) is a small commercial device used widely in food field. A TTI system on the basis of the chemical reaction between urease and carbamide was developed. The discoloration kinetics of urease-based TTI was explored. The mathematics formula that revealed the relationships of the change of TTI color with time and temperature has been established. The activation energy of urease-based TTI was 23.05 +/- 1.15 kJ/mol (+/- 95% confidence interval). This type of TTI system has the potential to apply to some time temperature dependence foods with similar Ea values. (C) 2013 Elsevier Ltd. All rights reserved.