Potential benefits of the application of yeast starters in table olive processing

Abstract

Yeasts play an important role in the food and beverage industry, especially in products such as bread, wine, and beer, among many others. However, their use as a starter in table olive processing has not yet been studied in detail. The candidate yeast strains should be able to dominate fermentation, together with lactic acid bacteria, but should also provide a number of beneficial advantages. Technologically, yeasts should resist low pH and high salt concentrations, produce desirable aromas, improve lactic acid bacteria growth, and inhibit spoilage microorganisms. Nowadays, they are being considered as probiotic agents because many species are able to resist the passage through the gastrointestinal tract and show favorable effects on the host. In this way, yeasts may improve the health of consumers by means of the degradation of non-assimilated compounds (such as phytate complexes), a decrease in cholesterol levels, the production of vitamins and antioxidants, the inhibition of pathogens, an adhesion to intestinal cell line Caco-2, and the maintenance of epithelial barrier integrity. Many yeast species, usually found in table olive processing (Wickerhamomyces anomalus, Saccharomyces cerevisiae, Pichia membranifaciens, and Kluyveromyces lactis, among others), have exhibited some of these properties. Thus, the selection of the most appropriate strains to be used as starters in this fermented vegetable, alone or in combination with lactic acid bacteria, is a promising research line to develop in the near future.

Table Olive Fermentation Using Starter Cultures with Multifunctional Potential

“…These factors can inhibit the growth of fungi and other undesirable microorganisms such as yeasts and bacteria [51,52]. …”

“…This acid, because of its ability to form chelates with metal ions such as calcium, iron and magnesium, creates insoluble complexes whose degradation requires specific enzymes. Because of the absence of these enzymes into the human gastrointestinal tract, the dephosphorylation of these complexes could be succeeded by microorganisms’ enzymes [52,58,59]. …”

“…An important characteristic of starter cultures is their ability to adhere on the surface of the olive fruit [52,60]. The dominant species of the fermentation define the final characteristics of the olives.…”

“…Yeasts are known for their ability to produce different compounds such as ethanol, glycerol, higher alcohols, esters and other volatiles which contribute decisively to the formation of flavor while maintaining the texture of the olive fruit during fermentation [52,81,82]. …”

“…An adequate consumption of folic acid could reduce the risk of heart diseases and cancer. Yeasts follow the folic acid production biosynthetic path [52,58]. …”