Phenolic composition of white wines with a prefermentative maceration at experimental and industrial scale

The influence of prefermentative maceration variables (time and temperature) on the phenolic profile of white wines elaborated at experimental and industrial scales has been evaluated. For this purpose, a total of 18 white wines were elaborated: six in a traditional way (control wines), and 12 by applying different skin contact times (2, 6, 12 and 24 h) and temperatures (5, 10 and 20 degrees C). They were made in a wine-production centre at two production levels: experimental (600 L) and industrial (30,000 L) level. The assayed wines compared to their corresponding control wines showed that the skin contact process increased the levels of phenolics in the final wines. The comparison between the two production levels (experimental and industrial) showed that the maceration process produce the same effect. However, the industrial wines showed a higher total phenolics content having higher concentration of hydroxycinnamates, mainly caffeic, caftaric, and p-hydroxybenzoic acids, and a lower concentration of flavonols such as epicatechin and quercetin-3-rutinoside. (c) 2006 Elsevier Ltd. All rights reserved.