Carbon isotope ratio (Δ13C) and phenolic profile used to discriminate wines from Dealu mare and Cotnari regions (Romania)

The species and origin used for red wine oak aging determines the physiological composition of the wood and thus the finished wines. In America, oak is grown primarily in the states of Virginia, Missouri, Kentucky, Oregon, Ohio, Minnesota, Wisconsin and California. The aim of this study was to analyze how the choice of barrels made with Quercus Alba oak from different geographic areas of the United States (Missouri, Kentucky, Ohio and Pennsylvania) influences the polyphenolic composition of Tempranillo red wines.

Samples from 3 wine types were treated with a cationic exchange resin (7 lots) and stored for 8 years (47 samples). Forty-seven parameters were determined, including (1) important substrates with impact in white wine oxidation and (2) markers of oxidation. From group 1, sugars, elements, phenolic compounds, α-dicarbonyls and SO2 and from group 2, browning (A420), acetaldehyde, alkanals, furanic compounds were quantified.

The importance of the non-Saccharomyces yeasts (NSY) in winemaking has been extensively reviewed in the past for their aromatic or bioprotective capacity while, recently their antioxidant/antiradical potential has emerged under winemaking conditions. In the literature the antioxidant potential of NSY was solely explored through their capacity to improve glutathione (GSH) content during alcoholic fermen- tation [1], while more and more studies pointed out the activity of the non-glutathione soluble fraction released by yeasts [2].

The phenolic component of red wine is responsible for important elements of flavor and mouthfeel, and thus quality of the finished wine. Additionally, many of these phenolics have been associated with health benefits such as reduction of the risk of developing cardiovascular disease, cancer, osteoporosis and preventing Alzheimer’s disease. While the origins, concentrations, and chemistries of the phenolics in a finished red wine are well known, the fundamental mechanisms and kinetics of extraction of these phenolics from grape skins and seeds during red wine fermentation are poorly understood. This lack of knowledge regarding the extraction mechanisms of phenolics during red wine fermentation makes informed manipulations of the finished wine’s phenolic composition difficult.

AIM: Cork, the bark of Quercus suber L. is a natural, renewable, sustainable, and biodegradable raw material, representing an abundant and cheap source of raw material. Portugal is the major cork producer (185,000 tons) processing about three-quarters of the world’s cork, generating up to 25 wt % of cork dust as a by-product.