Factors Affecting the Efficacy of Chlorine Against Esherichia Coli O157 H7 and Salmonella On Alfalfa Seed

Factors affecting the efficacy of chlorine against Esherichia coli O157:H7 and Salmonella on alfalfa seed

pp. 135-149Food Microbiology, Vol. 19, No. 2/3, April/June 2002, ISSN: 0740-0020, EISSN: 1095-9998 ,

W. F. Fett

Illnesses due to consumption of alfalfa and other types of sprouts contaminated with bacterial human pathogens continue to occur both in the US and in other countries. As the original source of the pathogen is almost always t he seed used for sprouting, improved methods for sanitizing sprouting seed are needed. In this study we wished to determine the efficacy of combining water rinses of alfalfa seed along with treatment with high levels of chlorine (18,000 ppm). Such treatments resulted in 99.99% reductions of two pathogens, Salmonella and Escherichia coli O157:H7, from alfalfa seed that had been inoculated in the laboratory. Similar treatment of alfalfa seed naturally contaminated with Salmonella led to the complete elimination of the pathogen. Most of the 29 types of sprouting seed tested could withstand such a treatment without a drastic reduction in seed germination rate or percent age. Treatment of sprouting seed with high levels of chlorine along with water rinses should significantly reduce or eliminate outbreaks of foodborne illness due to contaminated sprouts.