Sequential treatment of hydrogen peroxide, vacuum packaging, and dry heat for inactivating Salmonella Typhimurium on alfalfa seeds without detrimental effect on seeds viability

Abstract

The aim of this study was to inactivate Salmonella Typhimurium loaded onto alfalfa seeds with sequential treatment of hydrogen peroxide, drying, vacuum packaging, and dry heat. Also, we verified the effect of vacuum packaging in dry heat treatment. Populations of Salmonella on alfalfa seeds after sequential treatment were not detected after 8 or 3 h of dry heat treatment at 70 or 73 °C. Salmonella populations including injured cells were also reduced to below the detection limit after 8 or 4 h of dry heat treatment. The germination rate of alfalfa seeds subjected to the harshest treatment was not significantly different (P > 0.05) from that of untreated seeds. Vacuum packaging is conducive to preserving the moisture content of alfalfa seed and improving the efficiency of dry heat treatment. This study suggests that sequential treatment is recommended and applicable for decontaminating alfalfa seeds for sprout production.

Keywords: Alfalfa seeds; Dry heat; Hydrogen peroxide; Salmonella; Sprouts; Vacuum packaging.