Microbiological Studies on Cheese (I): Yeast Florae in Cheese Imported from Europe and North America

Abstract

Yeast florae of twelve samples of commercially available cheese imported from Europe and North America were investigated. Five samples out of twelve were found to contain 106-108/g of yeasts. In three kinds of blue cheese, Superzola, Roquefort, and Valencay, Debaryomyces hansenii and its imperfect counterpart, Torulopsis candida, were the exclusive species of the florae. About 90% of yeast flora was occupied by D. hansenii-T. candida, and the remaining 10% by Candida zeylanoides in the case of Plumrose (blue cheese). Geror, a non-ripening cheese, contained 105-108/g of Candida lipolytica, and D. hansenii was the minor constituent of the yeast flora. Only a small number of yeasts were found in Baby Edam, Cheddar, Camembert, and Viola (cream) cheese, and no yeast was detected in Emmental cheese. In addition to the species mentioned above, Kluyueromyces lactis, Saccharomyces italicus, Sporobolomyces roseus, Candida intermedia, Candida kefyr, Cryptococcus albidus, Cryptococcus luteolus, Rhodotorula rubra, and Rhodotorula minuta were detected as minor members of microflora of eleven samples. The yeast florae of blue cheese found in the present investigation differed from those previously reported in cheese during the ripening. This suggests a possible change of yeast flora in blue cheese after ripening. © 1977, Japanese Society for Food Hygiene and Safety. All rights reserved.