Efficacy of yeast starters to drive and improve Picual, Manzanilla and Kalamàta table olive fermentation

BACKGROUND: Table olive fermentation is an unpredictable process and frequently performed using traditional practices often inadequate to obtain products with acceptable quality and safety standards. In the present study, the efficacy of selected yeast strains as starters to drive fermentations of green and black table olives by the Greek method was investigated. Pilot-scale production by spontaneous fermentation as a control, olives started with previously selected Saccharomyces cerevisiae strains and fermentation driven by commercial S. cerevisiae baker’s yeast strain were carried out for each of Manzanilla, Picual and Kalamàta table olive cultivars. RESULTS: Timeof fermentationwas significantly shortened to 40 days to complete the transformation process for all three tested cultivars. Inoculated table oliveswere enhanced in their organoleptic and nutritional properties in comparisonwith corresponding samples obtained by spontaneous fermentation. The use of starters was also able to improve safety traits of table olives in terms of biogenic amine reduction as well as absence of undesiredmicroorganisms at the end of the process. CONCLUSIONS: Autochthonous, but also non-autochthonous, yeasts can be used to start and control table olive fermentations and can significantly improve quality and safety aspects of table olives produced by many smallholder farmers.