Abstract
This study has been conducted to investigate the temperature dependence and mass transfer kinetics of a microbial time-temperature integrator (TTI) developed by using emulsification/internal ionotropic gelation method. We report the effect of the Na-alginate concentrations (0.5%, 2.0%, 4.0% and 6.0% w/v) and temperature (8, 15, 20, 25 and 30 °C) on the TTI responses (changes in pH and titratable acidity [TA]). Results revealed that Ca-alginate microbeads (Ca-AMs) prepared from 2.0% Na-alginate were more uniform and smaller, with a narrow size distribution, in comparison with the other Ca-AMs. For microbeads with above 2.0% Na-alginate, the TTI response rates decreased because of the lower diffusion efficiency. Linearity in the TA was greatest for the 2.0% Ca-AMs. Therefore, the mass transfer and TTI response kinetics data demonstrated that 2.0% Na-alginate was optimal for producing Ca-AMs from which an ideal microbial TTI could be developed to monitor food spoilage processes with accuracy and precision.