Yeast mannoproteins released during the process of aging wine on the yeast lees have been reported to make important contributions to wine quality. However, few mannoproteins have been identified in wine and their lifespan during aging is unknown. As a first step towards better understanding the contributions of yeast mannoproteins...
Constituents of the wine matrix, including ethanol, affect adsorption of sulfur volatiles on solid-phase microextraction (SPME) fibers, which can impact sensitivity and accuracy of volatile sulfur analysis in wine. Several common wine sulfur volatiles, including hydrogen sulfide (H2S), methanethiol (MeSH), dimethyl sulfide (DMS), dimethyl disulfide (DMDS), dimethyl trisulfide (DMTS), diethyl...
Proanthocyanidins (PACs) containing A-type linkages, like those found in cranberry, have been implicated as beneficial phenolic compounds in human health, but much research is still required to better understand their activity fully. One major impediment to progress has been the existence of effective analytical methods for A-type PAC quantification. This...
Three analytical methods for determination of aroma compounds in alcoholic beverages were developed and validated. These methods are sensitive and reliable that can be applied to analyze volatile phenols, stale aldehydes as well as some highly volatile aromas in alcoholic beverages. In the first study, an ethylene glycol (EG) polydimethylsiloxane...
The objectives of this study were to 1) measure and compare the compositional differences of essential oil among three hop cultivars ('Centennial’, 'Citra' and 'Nelson Sauvin'), 2) identify the odor-active aroma compounds in three varieties of hops and 3) investigate the behavior of hop-derived aroma compounds in beers prepared by...
Proanthocyanidins are a grape-derived phenolic class of compound that provide wine with bitterness and astringency. Because of this, proanthocyanidins are considered to be essential components of wine quality. Proanthocyanidins are localized in the seed, skin and stem tissue of the grape berry and the composition of proanthocyanidins will vary depending...
Grapevine red blotch virus (GRBV) is a single-stranded DNA virus that causes grapevine red blotch disease (GRBD). Symptoms of GRBD include red discoloring of leaf margins and red veins on the underside of the leaves. GRBD affects the plant's metabolism and photosynthetic pathways, and disrupts carbon translocation and chlorophyll concentrations....
Wine volatile composition is one of the most important components of wine quality, and it is greatly affected by multiple factors, including grape variety, viticultural practices, and winemaking procedures. Pre-fermentation cold soak is one of the winemaking techniques widely undertaken by winemakers to modify their red wine quality. Imposing a...
Representing the most common flavonoid consumed in the American diet, the flavanols and their polymeric condensation products, the proanthocyanidins, are regarded as functional ingredients in various beverages, whole and processed foods, herbal remedies and supplements. Their presence in food affects food quality parameters including astringency, bitterness, sourness, sweetness, salivary viscosity,...
The water status of grape vine throughout the growing season is a primary determinant of vine vigor and berry composition. The concentrations of volatile compounds and precursors in grape berries are highly influenced by viticultural practices. Imposing a water deficit on the vine during berry development is an important vineyard...