Desiccation and thermal resistance of Salmonella and Enterococcus faecium NRRL B-2354 in almond meal as impacted by water activity and storage temperature

Almond products have been implicated in multiple outbreaks associated with Salmonella. In this study, the survival of Salmonella almond meal under different water activity (aw) was evaluated over one-year storage at 4 and 22 °C. The impacts aw during heat treatment on thermal tolerance Enterococcus faecium NRRL B-2354 were further assessed prior to after storage. inoculated E. or a three-strain cocktail equilibrated 0.25 0.45 samples subjected isothermal treatments before remained stable for 1 year °C regardless aw. count declined by 0.8 1.5 log10 CFU/g Under all test conditions using either death time (TDT) (TWA) cells, inactivation kinetics fitted log-linear model well; both bacteria inversely related meal. D-values obtained TDT cells 49.6, 18.0, 8.5 min 80, 85 90 °C, respectively, but 27.5, 13.7, 7.0 sample same temperatures. 85–95 TWA which relatively heating 2.0–2.4 times those determined where change heating. 1.3–1.5 1.6–1.8 Salmonella, indicating that suitable surrogate pasteurization constant moisture Furthermore, resistance not affected data provide useful information food industry designing processes ensuring safety products.