Evolution of Polyphenols, Volatile Aroma Compounds and Natural Yeast Flora of Coda di Volpe White Grape

Abstract

Wine is one of the main product of the agro-food products in Italy especially for its economic importance to local and regional level. The Campania region is excellent for the production of wine especially those of value, thanks to the presence of wide known varieties of native grapes. The aim of this work is been to characterize the chemical, biochemical and microbiological properties of Coda di Volpe grapes, cultivated in two areas, the hills and flat lands of Benevento. The name Coda di Volpe means tail of the fox, which was given in reference to the varieties of long, pendulous bunches of grapes, which resembles a fox's bushy tail. The polyphenols, pH, total acidity and °Brix were determined at different stages of maturation in order to identify the optimal time for the harvest. In particular, the total polyphenols content was evaluated with Folin-Ciocalteu method, while the specific polyphenols were determined by RP-HPLC. The grapes were harvested in sterile bag, sealed, pressed and incubated at 20°C for 1 month. During the fermentation it was isolated epiphytic microflora and characterized in order to analyse the physiological, oenological and technological properties. Three different yeast strains were assayed in their oenolegical ability, these were used in experimental fermentation with Coda di Volpe must. During alcholic fermentation have been evaluated yeast population, alcoholic grade and the volatile profile by the SPME-GC/MS technique. The data obtained have highlighted their ability to conduct the fermentation process, dominate the indigenous microflora and contribute to the definition of the flavour profile.