Heat Resistance Studies on Yeast spp. Causing Spoilage in Soft Drinks

摘要

A test method to investigate the heat resistance of yeasts has been developed. The method was used to study the heat resistance of 120 yeast strains, representative of the fungal flora in soft drinks and certain acid food products: 35 asporogenous yeast strains (Brettanomyces, Candida, Kloeckera, RhodotorulaandTorulopsis) and 85 ascomycetous strains (Debaryomyces, Hansenula, Kluyveromyces, Lodderomyces, Pichia, SaccharomycesandSaccharomycopsis) were tested. Generally, asporogenous yeasts were found to be less heat resistant than ascomycetous types. The genusSaccharomycesshowed the highest heat resistance, especially strains of the speciesSacch. cerevisiaeandSacch. chevalieri. For an evaluation of the practical implications of these results additional studies on environmental factors influencing the heat resistance of ascomycetous yeast species are required.