Combined effect of temperature and propionic acid concentration on the growth of Aspergillus parasiticus

Abstract

Effects of temperature (25, 30 and 36°C) and propionic acid concentration (129, 258 and 516 ppm) on the growth of Aspergillus parasiticus in solid media were analyzed. Growth rate, expressed as the increment of colony diameter per unit of time, was studied as a function of storage time employing the Arrhenius model. The inverse of the lag phase was fitted to an Arrhenius-type equation and the inhibition index was also calculated. A linear relationship between the lag phase and the reciprocal growth rate at different propionic acid concentrations was assessed by linear regression analysis. Fungi behavior was modeled considering the main controlling factors and a response surface methodology was established in terms of propionic acid and temperature. The proposed model could be used in food microbiology to predict the growth of toxicogenic fungi growth.