No knock on wood: Aging in barrels may improve wine’s healthful properties

Good wine gets better with age, but are aged wines better anti-aging remedies? This is likely true if some of the aging was in oak barrels. Aging wine in barrels is an ancient practice, and despite occasional excesses and changes of taste, it is as hard to imagine a big red without oak as it is beer without hops. The oak barrel in common use today has its origins at least as far back as the 3rd century BCE, when they began to replace ceramic amphorae for wine transportation. (Glassblowing is a similarly early development, but for several reasons glass bottles were not in common use until the 18th century.) Whether in the barrel or the bottle, the specific chemical changes in wine with aging have only recently been studied, and the implications for healthy drinking are emerging.

 Oak-derived compounds improve the wine if managed carefully, but these molecules also affect the health benefits of wine in unique ways. Collectively they are called “lignin-derived polyphenols,” which bear a relationship to polyphenols from grape skin and seeds. These molecules are often aromatic, as exemplified by vanillins and cinnamates. The prolonged time that red wines often spend in barrels can result in a high degree of extraction, though levels may still be small in comparison to polyphenols from the fruit. Nevertheless, their contribution to wine’s effects on health may be as important as their input to flavor and structure, according to recent research.

Oak adds unique antioxidant polyphenols

A study from the University of Alabama found impressive antioxidant capabilities of lignin polyphenols, with free radical scavenging potency in the same range as wine phenolics. Of particular interest is that these compounds bind many of the same proteins as resveratrol, indicating they may send similar metabolic signals in the body. The authors of the study concluded that oak phenolics likely contribute to prevention of cancer and heart disease to a significant degree, both from antioxidant activity and these specific protein interactions. (Cognac, whisky, even mezcal develop enhanced antioxidant capacity as a result of prolonged contact with oak!)Toasting of the barrels also substantially affects the polyphenol profile of the wines, notably by increasing a polyphenol called ellagic acid, known for its antimutagenic, anticarcinogenic, and antiviral capacities.

Traditional methods of winemaking are on the decline though, and the effects of newer techniques such as micro-oxygenation instead of prolonged barrel aging may change the composition of the final product. Oak chips are being substituted for the barrel, and powdered oak tannins are being used to shortcut the process even more. To be sure, barrels are one of the more costly aspects of winemaking, but I guess I am a traditionalist. I am willing to let the angels have their share (the evaporative loss from aging in oak) in return for something I know is good.

References

Alañón, M.E.; Castro-Vázquez, L.; Díaz-Maroto, M.C.; Gordon, M.H.; Pérez-Coello, M.S. A study of the antioxidant capacity of oak wood used in wine ageing and the correlation with polyphenol composition. Food Chem. 2011, 128, 997–1002.

Del Alamo Sanza, M.; Nevares Domınguez, I.; Cárcel Cárcel, L.M.; Navas Gracia, L. Analysis for low molecular weight phenolic compounds in a red wine aged in oak chips. Anal. Chim. Acta 2004, 513, 229–237.

Tao, Y.; García, J.F.; Sun, D.-W. Advances in wine ageing technologies for enhancing wine quality and accelerating wine ageing process. Crit. Rev. Food Sci. Nutr. 2014, 54, 817–835.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s