Purpose: The purpose of this study was to conduct a meta-analysis on kinetic inactivation parameters of HRM in a variety of foods.
Methods: Data were obtained from scientific papers, dissertations and thesis. From a total of 45 scientific papers and 7 thesis/dissertations, 13 were selected because they either presented raw data on HRM inactivation kinetics, D-values or time-to-reduce a determined population. D-values (time required at specific temperature for 1 log reduction in the population of the microorganism) or δ (time for the first decimal reduction) at 85°C for different HRM in different substrates were compared.
Results: A total of 124 inactivation kinetics/D- or δ values were obtained for different HRM species and strains in several foods. Most data corresponded to inactivation kinetics/D- or δ values estimated using fruit juices or fruit-based fillings. Most inactivation kinetic data followed non-log linear inactivation kinetics. Overall, N. fischeri presented significantly higher D- or δ values at 85°C than T. flavus (P < 0.05) but not than Byssochlamys (P > 0.05). Average D- or δ values at 85°C found for N. fischeri, Byssochlamys and T. flavus were 1.60, 1.32 and 1.35, respectively. z-values ranged from 6.0°C, 6.5°C and 8.0°C for Byssochlamys, N. fischeri and T. flavus, respectively. Several factors were shown to affect HRM heat resistance.
Significance: The knowledge of variability in HRM heat resistance is of major importance for the design of thermal processes that ensure the inactivation of these microorganisms in foods. This is a growing concern because consumer's demand for mildly processed foods may increase the role and importance of HRM as food spoilers.