OPTIMIZING SMALL-SCALE PRODUCTION OF FRESH WINE YEAST BIOMASS

摘要

The present study sought to optimize fresh wine yeast biomass production in annaerated fermenter fed with different volumes of concentrated grape must. Variablesnmost likely to influence the process were tested at high and low levels, in antotal of 13 fermentation runs. The production process was scaled up to pilot plantnlevel, and the yeasts thus obtained were inoculated into wine fermentation tanksnin a winery to evaluate their implantation during alcoholic fermentation.nThe best fermentation conditions were those used for batches carried out atn34C, 15°Brix and initial inoculum of 5.0 × 107 cells/mL; in these cases, cells displayednhigh protein and phosphorus content, a good P2O5/N ratio and appreciablenaccumulation of intracellular trehalose, indicating that the process was not toonmuch stressful. Generally, biomass exhibited adequate vitality throughout storagen(80%). The yeast produced retained a high degree of vitality and viability after 2nweeks of refrigeration; for this, seasonal production could, to some extent, benmatched to the needs of the winery.nSmall-scale laboratory production of fresh yeast biomass could help small wineriesnenhance the concept of terroir. This study confirmed that small amounts ofnfresh biomass can be sufficient as inoculum in winemaking.