Virgin olive oil yeasts: A review

Area of Science:

• Food Microbiology
• Oenology
• Fermentation Science

Background:

• Yeasts are the typical microbiota in virgin olive oil, originating from solid particles and vegetation water.
• Approximately seventeen yeast species have been identified in olive oils, including six newly discovered species.

Purpose of the Study:

• To review current knowledge on the role of yeasts in virgin olive oil.
• To discuss the impact of specific yeast species on olive oil quality and sensory characteristics.

Main Methods:

• Literature review of studies on yeast species isolated from olive oils.
• Analysis of yeast contributions to olive oil flavor, defects, and spoilage.
• Discussion of yeast survival in flavored olive oils.

Main Results:

• Certain yeast species enhance sensory qualities, while others cause defects like unpleasant flavors and triacylglycerol hydrolysis.
• Specific strains of Candida adriatica, Nakazawaea wickerhamii, and Candida diddensiae can cause defects, though other C. diddensiae strains do not.
• A newly identified yeast, Brettanomyces acidodurans, may cause a wine-vinegary defect.

Conclusions:

• Yeast microbiota significantly influences virgin olive oil quality, with both beneficial and detrimental effects.
• Understanding yeast species and strains is critical for controlling olive oil quality and preventing spoilage.
• Further research into lipase-producing yeasts and their survival is needed.