Development of Enzymatic – Colorimetric Time – Temperature Integrator for Smart Packaging

Abstract

A new enzymatic-colorimetric time-temperature integrator (ECTTI) to evaluate temperature abuse in refrigerated products was developed with Tributyrin, pH indicator, and lipase Calb. The kinetic behavior of the ECTTI (0.01 µL.L-1 enzyme) was assessed at 5, 10, 15, 20, and 25ºC, evaluating changes in pH (≤7.2) and color (ΔE ≥12). Storage at 5°C provided stability of the enzyme indicator for 16 days, and temperature abuses caused stability reduction to 15, 10, 0.5 0.3 days, with 10, 15, 20, and 25ºC of storage, respectively. The sequential abuse of temperature stability of ECTTI was assessed by exposure at 5.0ºC for 2 h and 25ºC for 1 or 5 min, returning to 5.0ºC for another 2 h, until the change in pH and color. The ECTTI subjected to temperature abuses for 5 and 1 min/25°C, remained stable for 5 and 9 cycles, respectively. The results of ECTTI stability before application, obtained with separate buffer/enzyme/water + substrate/indicator solutions, stored at 5 or 25ºC, before the reactive mixing of solutions, kept their stability, demonstrating the possibility of use as a tool against the temperature abuse conditions.