Evaluation of Enterococcus faecium NRRL B-2354 as a surrogate for Salmonella during cocoa powder thermal processing.

Evaluation of Enterococcus faecium NRRL B-2354 as a surrogate for Salmonella during cocoa powder thermal processing. Food Microbiol. 2019 Sep;82:135-141 Authors: Tsai HC, Ballom KF, Xia S, Tang J, Marks BP, Zhu MJ Abstract Salmonella is capable of surviving in a low moisture environment for long periods. Once adapted to the xeric conditions, the thermal resistance of Salmonella is enhanced. Cocoa powder is a low water activity (aw) food (LawF) that is an essential component in a wide variety of desserts and ready-to-eat (RTE) foods and drinks. The aim of this study was to evaluate the desiccation and thermal resistance of Salmonella in cocoa powder, as well as to examine the suitability of Enterococcus faecium NRRL B-2354 as a surrogate for Salmonella during cocoa powder thermal processing. Natural unsweetened cocoa powder was inoculated with a 3-strain Salmonella cocktail or E. faecium and was equilibrated to aw 0.30 and 0.45 at room temperature, then subjected to isothermal treatments at 70-80 °C or 12-month storage at RT (room temperature, 22.0 ± 0.5 °C, aw 0.30). At 70 and 80 °C, D-values of both Salmonella and E. faecium increased with decreasing aw. D-values of Salmonella at aw 0.30 cocoa powder were 46.2 ± 4.7, 20.5 ± 1.7, and 11.5 ± 0.9 min at 70, 75 and 80 °C, respectively. Higher heat resistance of E. faecium in aw 0.30 cocoa powder was observed with D-values of 59.9 ± 5.0, 28.9 ±â€...
Source: Food Microbiology - Category: Food Science Authors: Tags: Food Microbiol Source Type: research