Isolation of Food Spoilage Yeasts from Salads Purchased from Delicatessens

Abstract

Reports on a study of the bacteriological and mycological quality of 87 prepared salads purchased from delicatessens. Bacterial counts were generally low. Of the 87 salads, only 19 per cent had plate counts greater than 104 organisms/g. Coliforms were isolated from three samples, E. coli from one and Listeria monocytogenes from one. By contrast yeasts were isolated from 76 per cent of the salads and at counts greater than 104 organisms/g in 31 per cent. Twenty‐one different yeast species were isolated, of which the commonest were Saccharomyces dairensis and Saccharomyces exiguus. Few of the yeasts have any significant role in human disease. The commonest yeasts isolated, however, are associated with spoilage of mayonnaise‐based salads. Their isolation from these foods suggests inadequate temperature control.