Pathogen detection, testing, and control in fresh broccoli sprouts

BACKGROUND: The recent increased interest in consuming green vegetable sprouts has been tempered by the fact that fresh sprouts can in some cases be vehicles for food-borne illnesses. They must be grown according to proper conditions of sanitation and handled as a food product rather than as an agricultural commodity. When sprouts are grown in accordance with the criteria proposed from within the sprout industry, developed by regulatory agencies, and adhered to by many sprouters, green sprouts can be produced with very low risk. Contamination may occur when these guidelines are not followed. METHODS: A one year program of microbial hold-and-release testing, conducted in concert with strict seed and facility cleaning procedures by 13 U.S. broccoli sprout growers was evaluated. Microbial contamination tests were performed on 6839 drums of sprouts, equivalent to about 5 million consumer packages of fresh green sprouts. RESULTS: Only 24 (0.75%) of the 3191 sprout samples gave an initial positive test for Escherichia coli O157:H7 or Salmonella spp., and when re-tested, 3 drums again tested positive. Composite testing (e.g., pooling up to 7 drums for pathogen testing) was equally sensitive to single drum testing. CONCLUSION: By using a "test-and-re-test" protocol, growers were able to minimize crop destruction. By pooling drums for testing, they were also able to reduce testing costs which now represent a substantial portion of the costs associated with sprout growing. The test-and-hold scheme described herein allowed those few batches of contaminated sprouts to be found prior to packaging and shipping. These events were isolated, and only safe sprouts entered the food supply

The production of cyclopiazonic acid by Penicillium commune and cyclopiazonic acid and aflatoxins by Aspergillus flavus as affected by water activity and temperature on maize grains

The combined effects of water activity (aw) and temperature on mycotoxin production by Penicilium commune (cyclopiazonic acid - CPA) and Aspergillus flavus (CPA and aflatoxins - AF) were studied on maize over a 14-day period using a statistical experimental design. Analysis of variance showed a highly significant interaction (P 0.001) between these factors and mycotoxin production. The minimum aw/temperature for CPA production (2264 ng g-1 P. commune, 709 ng g-1 A. flavus) was 0.90 aw/30 °C while greatest production (7678 ng g-1 P. commune, 1876 ng g-1 A. flavus) was produced at 0.98 aw/20 °C. Least AF (411 ng g-1) was produced at 0.90 aw/20 °C and most (3096 ng g-1) at 0.98 aw/30 °C