Lactic acid, commonly used in foods as a flavoring or preservative, can help reduce salmonella in two important organs of broiler chickens. One organ—the crop—is part of the chicken’s esophagus. The other organ—the ceca—is a blind pouch connected to the large intestine. Both organs are prone to bacterial contamination. ARS researchers added two tablespoons of lactic acid to 1.2 gallons of drinking water for pre-slaughter broiler chickens. Salmonella microbes were reduced by 41.5 percent in the crop and by 11.2 percent in the ceca. Poultry carcasses may become contaminated if these organs are ruptured during processing. If Salmonella is present, the highest concentration of bacteria is found in the ceca. But the bacteria in the birds’ crops are also significant, because the crop ruptures 86 times more often than the ceca in the processing plant. Lactic acid acidifies the content of these organs, making them less conducive to bacterial growth. Using food-grade lactic acid, the researchers estimate the cost is about 0.2 cent per bird.

Food Safety Research Unit, College Station, TX
J. Allen Byrd, (409) 260-9331, BYRD@ffsru.tamu.edu

By knocking out certain Salmonella genes, ARS food safety researchers may discover genes are crucial to this microbe’s ability to attack foods. The research, which is being conducted with the sprouted seeds of broccoli, radish, alfalfa, and mung bean, could lead to new and more effective tactics to thwart Salmonella not only in sprouts, but in other fresh produce—and perhaps even in meats and poultry—as well. The ARS investigation into the key Salmonella genes may be unique. So far, the experiments in which a gene or genes have been knocked out of lab strains of the pathogen have yielded a Salmonella that is only one-tenth as effective in colonizing fresh sprouts. Now scientists need to determine which of the 4,000 to 5,000 Salmonella genes are missing or disabled in that strain. The researchers expect that help in answering this question will come from scientists elsewhere who are collaborating in an international effort to determine the makeup and function of all Salmonella genes. Besides adding color, taste, and texture to salads, sandwiches, soups, and other dishes, sprouts provide protein, fiber, and antioxidants such as vitamin C.

Food Safety and Health Research Unit, Albany, CA
Amy O. Charkowski, (510) 559-5647, amy@pw.usda.gov