Proanthocyanidins are found in the seeds and skins of winegrapes and are extracted into the must-wine during maceration. For 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.
Spectrophotometric and chromatographic results showed that ethanol was not required for proanthocyanidin extraction, although its presence increased the rate of extraction.
Extraction dynamics indicated that alcohol increased the rate of proanthocyanidin extraction for the initial six days of maceration, after which, even in the absence of ethanol, the 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.
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