From 1995 to 1998, eleven reported outbreaks involving about 1200 cases of Escherichia coli O157:H7 and Salmonella infections in the U.S. have been associated with consumption of alfalfa sprouts. The overall goal of this research is to develop a procedure to kill E. coli O157:H7 and Salmonella on alfalfa seeds without reducing the ability of the seeds to germinate and produce sprouts.
Objectives are to determine: 1) the effectiveness of combinations of detergents and disinfectants in killing these pathogens; 2) the effectiveness of simultaneous application of heat and detergents/disinfectants on inactivation of these pathogens; 3) the efficacy of these treatments in eliminating pathogens on various types of alfalfa seeds; and 4) the ability of E. coli O157:H7 and Salmonella to survive on alfalfa seeds as influenced by temperature and relative humidity. Detergents to be evaluated include those exempted by the U .S. Environmental Protection Agency and the Food and Drug Administration from requirement of tolerance and are generally recognized as safe (GRAS). Disinfectants to be tested will include those known to be effective in removing microorganisms from raw fruits and vegetables. Effectiveness of treatments in killing E. coli O157:H7 and Salmonella at temperatures ranging from 70 to 175 F will be determined.Survival of these pathogens on alfalfa seeds stored at 40 to 140 F for up to 2 years will be monitored.Viability of seeds as affected by all test treatments will be determined. Information gained from this research will be valuable in developing strategies to eliminate E. coli O157:H7 and Salmonella from alfalfa seeds as well as other seeds intended for sprout production, thus greatly minimizing the risk of illness associated with eating of raw seed sprouts.