Six malo-lactic strains of lactic acid bacteria were isolated from California wines and identified as Lactobacillus delbrueckii, L. buchneri, L. brevis, Leuconostoc citrovorum, and two strains of Pediococcus cerevisiae. Malo-lactic fermentation was induced in separate lots of wine by inoculation of each lot with one of the strains of bacteria. Malo-lactic fermentation had occurred in each inocu...

The effects of five technological procedures and of the contents of total anthocyanins and condensed tannins on 19 fermentation-related aroma compounds of young red Mencia wines were studied. Multifactor ANOVA revealed that levels of those volatiles changed significantly over the length of storage in bottles and, to a lesser extent, due to other technological factors considered; total anthocyan...

During the vinification process, we can generally separate four main phases associated with specific microbial dominances: (i) first stages of alcoholic fermentation (AF) (non-Saccharomyces), (ii) most part of AF, up to the end (Saccharomyces), (iii) malolactic fermentation (MLF) (lactic acid bacteria or LAB), and (iv) undesired changes associated to microbial metabolism (spoilage yeasts and ba...

In wines, the presence of sulfur compounds is the resulting of several contributions among which yeast metabolism. The characterization of the starter Saccharomyces cerevisiae needs to be performed also taking into account this ability even if evaluated together with the overall metabolic profile. In this perspective, principal aim of this experimental research was the evaluation of the volatil...

This work discusses the determination of the provenance of commercial Torrontés wines from different Argentinean provinces (Mendoza, San Juan, Salta and Rio Negro) by the use of UV-vis spectroscopy and chemometric techniques. In order to find classification models, wines (n = 80) were analyzed using UV-Vis region of the electromagnetic spectrum. Principal component analysis (PCA), linear discri...

The recent finding that grape tannin may contain significant amount of S-glutathionylated (GSH-3MH) and S-cysteinylated (Cys-3MH) precursors of the varietal thiols 3-mercapto-1-hexanol and 3-mercaptohexyl acetate, characteristic of Sauvignon blanc wines, offers new opportunities for enhancing the tropical aroma in fermented beverages. In this study this new hypothesis was investigated: Müller T...

Sorbic acid was added to wines in different concentrations to determine its effect on the inhibition of yeasts in semi sweet wines. Sorbic acid proved to be an effective inhibitor of yeast growth when used at a concentration of 200 mgle in conjunction with a concentration of 100 mg S02IC. As the sorbic acid does not kill the yeast cells but only inhibits them it is imperative that the wine shou...

Four regulated deficit irrigation (RDI) regimes were applied to Cabernet Sauvignon grapes, which were analyzed for phenolics and also made into wine over three consecutive growing seasons. Relative to an industry standard regime (IS), yield was reduced over the three years by 37% in a full-deficit (FD) regime and by 18% in an early deficit (ED) regime, whereas no yield reduction occurred with a...