Modeling inactivation of Listeria monocytogenes, Shigella sonnei, Byssochlamys fulva and Saccharomycescerevisiae and ascorbic acid and β-carotene degradation kinetics in tangerine juice by pulsed-thermosonication

Abstract

Inactivation of Listeria monocytogenes (serotype 4 ab), Shigella sonnei, Byssochlamys fulva and Saccharomyces cerevisiae and the degradation of β-carotene and ascorbic acid in tangerine juice subjected to pulsed-thermosonication were modeled using polynomial, log-logistic, Weibull, biphasic linear and modified Gompertz models. The models were assessed using the adjusted determination coefficient (adj-R2) and the root mean square error (RMSE). Then, Ward's clustering method was applied to classify the fitted models. The Weibull model showed correlation coefficients above 0.98. Moreover, a process performance criterion was developed to examine the simultaneous effect of inactivation of microorganisms and degradation of β-carotene and ascorbic acid. Results indicated the effect of temperature was higher than pulsed-ultrasound amplitude for L. monocytogenes, S. sonnei and S. cerevisiae, while the effect of these two parameters was similar for B. fulva. Regarding β-carotene and ascorbic acid, pulsed-sonication amplitude was the major parameter in decreasing theirs contents in juice. The treatment procedure in the optimal conditions had the highest effect on L. monocytogenes, while S. sonnei, S. cerevisiae and B. fulva were at similar levels. Therefore, the models obtained present a valuable tool to design and predict pasteurization processes of tangerine juice during pulsed-thermosonication.