Study of the Stability of Wine Samples for H-NMR Metabolomic Profile Analysis through Chemometrics Methods.

Wine is a temperature, light, and oxygen-sensitive product, so its physicochemical characteristics can be modified by variations in temperature and time when samples are either sampled, transported, and/or analyzed. These changes can alter its metabolomic fingerprinting, impacting further classification tasks and quality/quantitative analyses. For these reasons, the aim of this work is to compare and analyze the information obtained by different chemometric methods used in a complementary form (PCA, ASCA, and PARAFAC) to study H-NMR spectra variations of four red wine samples kept at different temperatures and time lapses.

Understanding the Biosynthetic Changes that Give Origin to the Distinctive Flavor of Sotol: Microbial Identification and Analysis of the Volatile Metabolites Profiles During Sotol ( sp.) Must Fermentation.

In northern Mexico, the distilled spirit sotol with a denomination of origin is made from species of . The configuration of the volatile metabolites produced during the spontaneous fermentation of sp. must is insufficiently understood.

Mezcal: indigenous strains and their potential as starter cultures.

In this study, 19 indigenous mezcal strains were screened for their tolerance to grow under different stress conditions and their potential use in fermentation. All strains were able to tolerate pH value of 3, significant levels of glucose (30%), ethanol (12% v/v), and temperature of 37 °C. Eleven of them were able to grow in presence of 15% of ethanol, but only CH7 and PA18 strains grew at 42 °C.

Predominant Yeasts During Artisanal Mezcal Fermentation and Their Capacity to Ferment Maguey Juice.

Artisanal mezcal is produced by the natural fermentation of maguey juice, which frequently results in a process that becomes stuck or is sluggish. Using selected indigenous starter inoculums of and non- yeasts is considered beneficial in overcoming these problems and thereby preserving the essence of the artisanal process. In this work, three hundred and four yeast isolates were recovered from 17 distilleries and then grouped by the ARDRA analysis, their restriction profiles were clustered in 15 groups.

Oxoester oxidoreductase activities in new isolates of Pichia anomala from apple, grape and cane juices.

Thirty-nine yeasts isolated from apple, grape and cane juices were screened for their oxidoreductase activity. The two strains of Pichia, one isolated from apple and one from cane juices, appear to be promising strains for oxidoreductase activity on alpha-oxoesters. They showed similar high yields in converting ethyl pyruvate to ethyl lactate as Saccharomyces spp.