Scientists Seek Strategies to Safeguard Fresh Sprouts

Scientists Seek Strategies to SafeguardFresh Sprouts
July 27,2000
ARS News Service
Agricultural Research Service, USDA

Freshsprouts make a crisp, crunchy and healthful addition to sandwiches, salads,soups, omelets and other dishes. Now, studies by Agricultural Research Servicescientists may lead to new ways to help protect raw sprouts from attack by E.coli, Salmonella or other pathogenic microorganisms. These microbes can flourishin the warm, moist indoor environment in which seeds are induced to sprout,according to microbiologist Amy O. Charkowski at Albany, Calif. Seeds purchasedby "sprouters" -- the growers who run the indoor operations that yieldsprouted seeds -- may already be contaminated by microbes harbored in irrigationwater, fertilizer, or bird or mouse droppings, according to Charkowski. She iswith the Food Safety and Health Unit at the ARS Western Regional Research Centerin Albany.

Inlaboratory studies with radish, alfalfa, broccoli and mung bean sprouts,Charkowski wants to determine what compounds produced naturally by the sproutssuch as amino acids -- nurture the attacking microbes. She will then determinewhether harmless bacteria might be applied to the sprouts to deprive thefood-poisoning microbes of the compounds vital to their attack.

Inother experiments, Charkowski intends to pinpoint genes that Salmonella turns on-- or "expresses" -- when it colonizes sprouts. Once scientists knowwhich Salmonella genes are crucial to successful attacks, the researchers may beable to develop a strategy to activate and amplify sprouts' natural protectivemechanisms.

Charkowskianticipates that the genes Salmonella activates are likely the same as those ituses when it invades other fresh produce -- and perhaps meats and poultry. Ifthat is the case, food safety strategies developed from the sprout research mayalso help protect these other foods from Salmonella.
ARS is USDA's chief research agency.