Grape musts sometimes reveal excess acidity. An excessive amount of organic acids negatively affect wine yeasts and yeast fermentation, and the obtained wines are characterized by an inappropriate balance between sweetness, acidity or sourness, and flavor/aroma components. An appropriate acidity, pleasant to the palate is more difficult to achieve in wines that have high acidity due to an exces...

Lavoisier (1) first pointed out that during the decomposition of the sugar molecule in the course of alcoholic fermentation, the molecule not only splits in two parts to form alcohol and carbon dioxide, but he also clearly indicated that alcoholic fermentation involves the phenomena of reduction and oxidation. Later workers have shown that the phenomenon of fermentation is not a simple process ...

A model to predict accurately pH evolution during alcoholic fermentation of must by Saccharomyces cerevisiae is proposed for the first time. he objective at least is to determine if the pH measurement could be used for predictive control. The inputs of the model are: the temperature, the oncentrations in sugars, ethanol, nitrogen compounds, mineral elements (magnesium, calcium, potassium and so...

For cost-effective and efficient ethanol production from lignocellulosic fractions of plant biomass, the conversion of not only major constituents, such as glucose and xylose, but also less predominant sugars, such as l-arabinose, is required. Wild-type strains of Saccharomyces cerevisiae, the organism used in industrial ethanol production, cannot ferment xylose and arabinose. Although metaboli...

Throughout alcoholic fermentation, Saccharomyces cerevisiae cells have to cope with several stress conditions that could affect their growth and viability. In addition, the metabolic activity of yeast cells during this process leads to the production of secondary compounds that contribute to the organoleptic properties of the resulting wine. Commercial strains have been selected during the last...

The aim of this study was to develop a kefir apple-based vinegar and evaluate this fermentation process using new methodology with Biospeckle Laser. Brazilian kefir grains were inoculated in apple must for vinegar production. In this study, the microbial community present in kefir, and correspondent vinegar, was investigated using Matrix Assisted Laser Desorption/Ionization - Time of Flight Mas...