Abstract:
Spoilage caused by yeasts is a constant, widespread problem in the beverage industry that can result in
major economic losses. Fruit juices provide an environment that allows the proliferation of yeast. Some
factories in South Africa are not equipped with laboratory facilities to identify spoilage yeasts and outsourcing
becomes a prolonged process which obstructs corrective action planning. This study aimed to establish
yeast diversity and apply a rapid method for preliminary identification of spoilage yeasts associated with a
small-scale fruit juice bottling factory. Yeast population in the factory was determined by isolation from the
production environment, process equipment and spoiled products. PCR-RFLP analysis targeting the 5.8S-ITS
region and D1/D2 sequencing was used for identification. A total of 207 yeasts belonging to 10 different
genera (Candida, Lodderomyces, Wickerhamomyces, Yarrowia, Zygosaccharomyces, Zygoascus,
Cryptococcus, Filobasidium, Rhodotorula/Cystobasidium and Trichosporon) were isolated and identified
from the production environment and processing equipment. Candida intermedia, C. parapsilosis and
Lodderomyces elongisporus were widely distributed in the factory. Zygosaccharomyces bailii, Z. bisporus,
Zygoascus hellenicus and Saccharomyces cerevisiae were isolated from the spoiled products. The data
provided a yeast control panel that was used successfully to identify unknown yeasts in spoiled products
from this factory using polymerase chain reaction-restriction length polymorphism (PCR-RFLP) comparative
analysis.
