Impact of Oak Wood Barrel Tannin Potential and Toasting on White Wine Antioxidant Stability

Abstract

Wines aged in oak wood barrels with various uniform tannin contents (which were classified according to their total ellagitannins contents as predicted by Near Infrared Spectroscopy on the untoasted wood) and different toasting levels (high precision toasting by radiation) were distinguished according to their overall abilities to resist against oxidation. Wine trials were carried out on two different vintages (2015, 2016) and three grape varieties (Sauvignon blanc, Seḿillon, Chardonnay). Regardless of the vintage and the wine matrix, a relationship was established between wine oxidative stability (based on EPR spin trapping methodology) and oak barrel tannin potential. The extraction kinetic of ellagitannins by wines appeared linear during barrel aging and achieved its maximum at six or eight months, in a grape variety dependent manner. Oak wood barrel tannin potentials and toastings had no effect on wine glutathione and polyphenols contents. However, wines aged in new barrels with both low and medium tannin potentials, preserved at the end of aging and important number of S−N containing compounds, which was in addition to the known ellagitanins, revealed wines better antioxidant stability.

Oxygen and SO2Consumption of Different Enological Tannins in Relationship to Their Chemical and Electrochemical Characteristics

“…An additional tannin source of enological relevance is provided by different forms of oak commonly used in winemaking, primarily oak barrels and oak chips or staves. Oak is rich in ellagitannins, mostly vescalagin, castalagin, and related derivatives, exhibiting unique chemical and biological activities of enological relevance. − As a result of the central role of tannins in wine quality, there is a great emphasis in obtaining wine tannin profiles that are adequate to the different wine styles being produced. − However, tannin management at the level of grapes and young and aged wine remains complex as a result of the high number of factors involved, such as variability of tannin evolution patterns during grape maturation, tannin extraction patterns during maceration, and sensory contribution of different tannin fractions . For this reason, commercial preparations of exogenous tannins are often added in the winery.…”

Hydrolyzable vs. Condensed Wood Tannins for Bio-based Antioxidant Coatings: Superior Properties of Quebracho Tannins

“…Wood tannins are currently used in food industry, e.g., as additives to improve wine aroma and taste, as crosslinkers to strengthen the network of vegetable-based food gelatins, as livestock food supplements to enhance meat quality, or as additives in antioxidant and antimicrobial active packaging [ 9 , 11 , 12 , 13 ].…”

On the origin of the antioxidant potential of selected wines: combined HPLC, QSAR, and DFT study

“…Besides the antioxidant effect, polyphenols contribute to the other quality parameters of wine, such as color and bitterness [9]. The amount of these compounds depends on several factors such as the location of vineyard, soil type, grapes' type, and production processes [10][11][12][13][14]. Wines also exhibit antimicrobial activity against various pathogens [15].…”