Abstract
Several lots of Chardonnay and Grenache blanc grapes were treated with pomace contact and/or hyperoxidation prior to clarification and fermentation. Changes in wine phenolic composition and browning susceptibility due to these prefermentation treatments are reported. Pomace contact wines contained larger concentrations of caftaric acid and flavans but lower amounts of 2-S-glutathionyl caftaric acid and were more susceptible to browning. Hyperoxidation induced losses of all phenolic constituents and increased wine resistance to browning. Variations in the chemical and sensory properties were examined by principal component analyses. Browning was highly correlated with the amount of flavans and especially procyanidin B1. Other compositional attributes were not affected by prefermentation treatments except for absorbance at 280 nm which was correlated with caftaric acid content and higher in pomace contact wines and for absorbance at 420 nm which increased with hyperoxidation. From the PCA of the sensory data, pomace contact appeared beneficial to Chardonnay wines and detrimental to Grenache wines. Hyperoxidation did not modify the wine sensory properties. It was successfully applied and may be of interest to avoid the undesirable browning resulting from phenolic extraction during pomace contact.
- Received May 1988.
- Copyright 1989 by the American Society for Enology and Viticulture
Sign in for ASEV members
ASEV Members, please sign in at ASEV to access the journal online.
Sign in for Institutional and Non-member Subscribers
Log in using your username and password
Pay Per Article - You may access this article (from the computer you are currently using) for 2 day for US$10.00
Regain Access - You can regain access to a recent Pay per Article purchase if your access period has not yet expired.