Effect of sequential dry heat and hydrogen peroxide treatment on inactivation of Salmonella Typhimurium on alfalfa seeds and seeds germination

•We set the dry heat step before H2O2 treatment to maximize efficacy of hydrogen peroxide.•Increasing dry heating time increased inactivation levels.•Sequential treatment with dry heat and H2O2 reduced populations by up to 3.6 log CFU/g.•Hydrogen peroxide accelerates germination and increases germination percentage.

The purpose of this study was to inactivate Salmonella Typhimurium on alfalfa seeds without having negative effect on seed germination. Inoculated alfalfa seeds were treated with dry heat at 60, 70 or 80 °C for 0, 12, 18 or 24 h followed by 2% hydrogen peroxide solution (10 min). Populations of Salmonella on alfalfa seeds treated with dry heat alone (60, 70 or 80 °C) for up to 24 h were reduced by 0.26–2.76 log CFU/g, and sequential treatment with dry heat and H2O2 reduced populations by 1.66–3.60 log CFU/g. The germination percentage of seeds subjected to sequential treatments was significantly enhanced to up to 97%, whereas that of untreated seeds was only 79.5%. This study suggests that sequential treatment with dry heat and hydrogen peroxide is applicable for reducing levels of Salmonella on seeds while simultaneously enhancing seeds germinability.