Influence of autochthonous Saccharomyces cerevisiae wine strains on polyphenol amount in Apulian red wines

Phenolic coumpounds present in grape berries are extracted from the skin, seeds and flesh during the winemaking process. These substances have a potentially positive effect, on human health, thus giving to red wine "bioactive properties" that an contribute to decrease the incidence of atherosclerosis, cancer, neurodegenerative diseases. Grape variety, quality, climate, geographical origin and phythopatologies can affect the quality and quantity of phenolic compounds that accumulate in the cells. Viticulture and vinification practice, which varies in different countries, determine the concentration of phenolic compounds in wine. During the vinemaking process numerous parameters, such as temperature, presence of seeds and berry skins and addition of enzymes, have been reported to affect the extraction of phenolic compounds during grape must fermentation. Conversely, poor knowledge is available on the effects of different yeast strains on the final concentration of polyphenols in red wine. Indeed, yeasts enzymatic activity are likely to influence the extraction of phenolic substances from grape tissues. With the aim to evaluate the existence of a potential correlation between polyphenols content, antioxidant capacity of wine and yeast starter cultures, three selected autochthonous strains of Saccharomyces cerevisiae, were used to inoculate large scale must fermentation. At the end of the process, the experimental wines obtained were evaluated for the content of different class of polyphenols and antioxidant capacity. The statistical analysis of obtained results revealed a significant influence of the autochthonous strain on the concentration of several class of polyphenols and total antioxidant capacity in the produced wines. The different strain influence on the analysed parameters assumes a technological significance and it strongly contribute in determining the final quality of the wine by influencing "functional parameters" important for the preservation of human health.