Temperature abuse initiating yeast growth in yoghurt

Bennie C. Viljoen, Analie Lourens-Hattingh, Bridget Ikalafeng, G. Péter

Research output: Contribution to journalArticle

41 Citations (Scopus)

Abstract

The occurrence of yeasts in dairy products is significant because they can cause spoilage, effect desirable biochemical changes and they may adversely affect public health. While fermentative and spoilage activities of yeasts at elevated temperatures are well known in many food and beverage commodities, little attention has been given to the specific occurrence and significance of yeasts in dairy products at these temperatures. Since yeasts play a substantial role in the spoilage of commercial fruit yoghurts, especially when cold storage practices are neglected, the deterioration of yoghurt samples obtained from the manufacturers were evaluated at different temperatures for a period of 30 days during this study. Total yeast were enumerated, isolated and identified from the yoghurt samples. The highest number of yeast populations, up to 10 5 and 106 cfu/g, was found when yoghurts were exposed to elevated temperatures in the range of 25°C, while lower yeast counts (103 and 104 cfu/g) were obtained from samples kept refrigerated at a temperature of 5°C. Based on the results obtained, the interaction between the yeasts and lactic acid bacteria resulted in a decline in pH values and the stabilization of viable lactic acid bacterial loads. The most prevalent yeast species isolated, included strains of Kluyveromyces marxianus, Saccharomyces cerevisiae, Saccharomyces exiguus and Yarrowia lipolytica.

Original languageEnglish
Pages (from-to)193-197
Number of pages5
JournalFood Research International
Volume36
Issue number2
DOIs
Publication statusPublished - 2003

Fingerprint

Yogurt
yogurt
Yeasts
yeasts
Temperature
Growth
temperature
spoilage
Dairy Products
dairy products
Lactic Acid
Yarrowia
Kluyveromyces marxianus
Kluyveromyces
Yarrowia lipolytica
Food and Beverages
Saccharomyces
Bacterial Load
products and commodities
cold storage

Keywords

  • Food
  • Spoilage
  • Yeasts
  • Yoghurt

ASJC Scopus subject areas

  • Food Science

Cite this

Temperature abuse initiating yeast growth in yoghurt. / Viljoen, Bennie C.; Lourens-Hattingh, Analie; Ikalafeng, Bridget; Péter, G.

In: Food Research International, Vol. 36, No. 2, 2003, p. 193-197.

Research output: Contribution to journalArticle

Viljoen, Bennie C. ; Lourens-Hattingh, Analie ; Ikalafeng, Bridget ; Péter, G. / Temperature abuse initiating yeast growth in yoghurt. In: Food Research International. 2003 ; Vol. 36, No. 2. pp. 193-197.
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