In an effort to understand the basis for sulfite detoxification in S. cerevisiae,
the functions of two genes were analyzed. SSU1, which encodes a plasma membrane
protein, was found to be required for efficient sulfite efflux. FZFl-4, a dominant
allele of a transcriptional activator of SSUl, was also found to...
Wine has recently been shown to be a possible protective agent against
microbial foodbome illness. The chemical environment of wine makes it difficult, if
not impossible, for microorganisms to survive. The low pH, high concentration of
organic acids, relatively high ethanol concentrations, and the potential for high levels
of sulfur...
Wine grape pomace (WGP), the byproduct from winemaking, is a good source of polyphenols and dietary fibers, and may be utilized as antioxidant dietary fibers (ADF) for food applications. The objectives of this thesis research were to first determine the phenolic compounds, antioxidant and antimicrobial activities in red WGP under...
Natural corks have long been used as wine closures. However, they are associated with causing multiple adverse effects to the wine they are attempting to preserve. Alternative closures such as synthetic corks and screw caps were developed in order to reduce and/or eliminate these problems. However, the major cause of...
Malolactic fermentation (MLF) is important in the production of wines as it reduces acidity through the conversion of malic acid to lactic acid. However, successful MLF can be difficult to achieve due to yeast antagonism of the bacterium responsible for
the secondary fermentation, Oenococcus oeni. In particular, yeast produced sulfur...
The yeast Brettanomyces bruxellensis is the most important wines spoilage yeast encountered during winemaking as it can survive in wine for long periods, requires minimal nutrients for growth, and can be difficult to control. Brettanomyces produces two major spoilage products, the volatile phenols 4-ethylphenol (Band-Aid, medicinal smell) and 4-ethylguaiacol (smoke,...
This study integrates various vineyard practices that may improve nitrogen availability to the vine, particularly during ripening. Different strategies aimed at increasing yeast assimilable nitrogen in the fruit at harvest have been evaluated. This study seeks to improve fermentation behavior and wine quality through vineyard practices used for nitrogen management....
Crop thinning trials were studied during two seasons at two locations in the northern Willamette Valley of Oregon. At Willakenzie Estate (site #1), research vines were Pinot noir clone Dijon 113 on 3309 rootstocks trained to a double Guyot. Vines were established in 1996 at a spacing of 2.5 x...