Moulds and yeasts in fresh and minimally processed vegetables, and sprouts

Abstract

A limited survey of fresh and minimally processed vegetables, and sprouts was conducted in the Washington, DC area to determine if potentially toxigenic and pathogenic fungi were present in these commodities. Thirty-nine ready-to-eat salads, 29 whole fresh vegetables and 116 sprout samples (bean, alfalfa, broccoli, crunchy, garlic, spicy, onion, clover, lentil and multi-seed sprouts) were purchased from 13 local supermarkets and tested for yeast and mould counts as well as the presence of toxigenic moulds. Yeasts were the most prevalent organisms found in these samples, at levels ranging from less than 100 to 4.0×10 8 cfu/g. Mould counts generally ranged from less than 100 to 4.0×10 4 cfu/g. Two crunchy sprout samples, however, contained unusually high numbers of Penicillium (1.1×10 8 and 1.3×10 8 cfu/g), two alfalfa sprout samples contained Geotrichum populations about 10 6 cfu/g, and two alfalfa sprout samples had Cladosporium counts higher than 2.5×10 5 cfu/g. The most common moulds found in fresh and minimally processed vegetables were Cladosporium, Alternaria and Penicillium; less common was Geotrichum. The most frequently isolated moulds from sprouts were Alternaria, Cladosporium, Penicillium, and Phoma. Phoma was especially common in alfalfa sprouts. Fusarium, Rhizopus, Mucor, and Geotrichum were isolated less often.