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High hydrostatic pressure inactivation kinetics of Escherichia coli ATCC 25922 and Salmonella enterica subsp. enterica serovar Typhimurium ATCC 14028 ( S. typhimurium) in a low acid mamey pulp at four pressure levels (300, 350, 400, and 450 MPa), different exposure times (0-8 min), and temperature of 25 ± 2℃ were obtained. Survival curves showed deviations from linearity in the form of a tail (upward concavity). The primary models tested were the Weibull model, the modified Gompertz equation, and the biphasic model. The Weibull model gave the best goodness of fit ( R

Sapote mamey is a highly perishable tropical fruit when stored fresh, with a shelf life of 8–10 days at room temperature. Its agreeable taste and nutritional content are valuable characteristics which can be preserved as a pulp, normally at low temperatures, to maintain initial quality. However, this type of fresh product can potentially be a substrate for pathogenic microorganisms like Listeria monocytogenes, which can survive at refrigeration temperatures. The objectives of this investigation were to determine growth, survival conditions and then establish hurdles, of L. monocytogenes inoculated into mamey pulp under different levels of ascorbic acid (0, 250, and 500 mg/kg), pH (4.0, 4.5, and >5.0), and temperature (4 and 10 °C). The observed data were fitted to the Gompertz and Baranyi models. Growth rate (μmax) and lag time (λ) of L. monocytogenes were estimated using the modified Gompertz model given that it presented a better goodness of fit and accuracy in the modeling. Growth was favored at pH >5.0. μmax decreased, whereas λ increased, as the levels of ascorbic acid and temperature increased. A pH of 4.5 hinders but does not inhibit bacterial growth, while a pH of 4.0 inhibited growth of L. monocytogenes for 15 days at both storage temperatures.