Thermal Inactivation of Salmonella and Escherichia coli O157:H7 on Alfalfa Seeds

Abstract

Alfalfa seeds inoculated with five strains of Salmonella or Escherichia coli O157:H7 were subjected to dry heat at 55°C for up to 8 days. Five-log reductions in Salmonella or E. coli O157:H7 on seeds were observed. No pathogens were detected on the sprouted seeds, which were initially inoculated with ca. 2 log CFU/g of Salmonella or more than 8 log CFU/g of E. coli O157:H7. The percentages of germination of the alfalfa seeds did not significantly decrease after 6 days of heating at 55°C. These results showed that heat treatment of alfalfa seeds at 55°C for up to 6 days was effective in enhancing the safety of alfalfa sprouts without affecting germination significantly.