PT  - JOURNAL ARTICLE
AU  - Alberto Hernández-Jiménez
AU  - James A. Kennedy
AU  - Ana B. Bautista-Ortín
AU  - Encarna Gómez-Plaza
TI  - Effect of Ethanol on Grape Seed Proanthocyanidin Extraction
AID  - 10.5344/ajev.2011.11053
DP  - 2011 Oct 12
TA  - American Journal of Enology and Viticulture
PG  - ajev.2011.11053
4099  - http://www.ajevonline.org/content/early/2011/10/11/ajev.2011.11053.short
4100  - http://www.ajevonline.org/content/early/2011/10/11/ajev.2011.11053.full
AB  - Proanthocyanidins are found in the seeds and skins of wine grapes, and are extracted into the must-wine during maceration. In the case of seed proanthocyanidins, extraction is generally thought to be possible only in the presence of ethanol. This study examined the extraction of seed proanthocyanidins in model solutions with increasing concentrations of ethanol, from 0 to 15% v/v. The spectrophotometric and chromatographic results showed that ethanol was not required for proanthocyanidin extraction although its presence increased the rate of extraction. The extraction dynamics indicated that alcohol increased the rate of proanthocyanidin extraction for the first six days of maceration, after which, even in the absence of ethanol, extraction rate was nearly identical for all treatments. These findings suggest that extraction time is an important consideration when managing techniques such as cold soak which are thought not to affect seed proanthocyanidin extraction.