Assessment of Pediococcus acidilactici ATCC 8042 as potential Salmonella surrogate for thermal treatments of toasted oats cereal and peanut butter.

The objective of this study was to evaluate the use of Pediococcus acidilactici ATCC 8042, a generally recognized as safe bacterium (GRAS), as potential surrogate for Salmonella in commercial toasted oats cereal (TOC) and peanut butter. P. acidilactici was compared to a five-serovar cocktail of Salmonella and Enterococcus faecium NRRL-B2354, separately. Cultures were inoculated into TOC and thermal kinetic parameters (δ, β) were determined at 80, 85, 90, and 95 °C using the Weibull model. In peanut butter, δ and β parameters were obtained at 63, 68, 73, and 77 °C. In TOC, the δ values (initial decimal reduction time) of P. acidilactici were 63 and 7 min at 80 and 95 °C, respectively, and at all four temperatures they were not significantly different from δ values of E. faecium. The δ value of Salmonella at 80 °C (139 min) was two-fold greater than the other two bacteria's values (p < 0.05). In peanut butter, δ values of P. acidilactici ranged from 31 min at 63 °C to 2.6 min at 77 °C, and at all temperatures they were not significantly different from E. faecium's δ values. In peanut butter, all Salmonella cocktail's δ values were significantly smaller than P. acidilactici's with values of 2 min at 63 °C and 0.4 min at 77 °C. These results indicated that P. acidilactici was as heat tolerant as E. faecium in these food matrices. However, the thermal inactivation kinetic parameters suggested that P. acidilactici can o...

Source: Food Microbiology - June 18, 2019 Category: Food Science Authors: Deen B, Diez-Gonzalez F Tags: Food Microbiol Source Type: research