Effects of yeast inoculation on volatile compound production by grape marcs

Abstract

Grape marcs are a by-product of winemaking that can be used for production of Grappa, a traditional Italian spirit. This plant material needs to undergo a fermentation process before distillation to allow production of ethanol from residual sugar and volatile aromatic compounds. To study the possible effect of selected yeast inocula on the fermentation process and subsequent quality of the distillate, a laboratory-scale fermentation of grape marcs was performed. The inoculated yeasts proved to be good colonizers of grape pomace and contributed markedly to rapid sugar consumption, which was completed within 5 days. Fermentation products were analysed by gas-chromatography. A time course analysis performed to determine the impact of the inoculated strains on the main aromatic compounds that are concentrated in the product after distillation provided evidence of a positive effect of yeast inoculation. © 2010 Springer-Verlag and the University of Milan

Effects of Distillation System and Yeast Strain on the Aroma Profile of Albariño (Vitis vinifera L.) Grape Pomace Spirits

“…38 The ability of inoculated yeast strains to prevail over the autochthonous microorganisms during grape marc fermentation and storage has also been reported for grappa production. 15 All L2 fermentations were considered for chemical analysis and ethanol yield determination.…”

“…On the other hand, the inoculated yeast used to ferment the grape pomace can influence notably the production of volatile compounds and the aroma quality of the final distillate. 15 Therefore, in this work, we applied two distillation systems (copper charentais alembic and packed column) and two yeast strains (native and commercial) to study their influence on chemical and sensory characteristics of the obtained distillates.…”

Microbial Resources as a Tool for Enhancing Sustainability in Winemaking

“…Marc is stored for a period lasting from a few days to several weeks, when fermentation of residual sugars occurs mainly by yeast activity, but bacterial populations can also develop and are often associated with off-flavor production [123][124][125]. Therefore, a careful management of the fermentation process during storage is increasingly being applied by distilleries, often employing marc acidification [122], temperature control [125], and yeast inoculation [126]. Research studies showed that the lowering of the pH [122] caused significant changes in the yeast-bacteria populations ratio and in yeast species turnover, determining an improvement of the aromatic profile of the distillate, due to the reduction of the main volatile products associated with potential off-flavors [122].…”

Characteristics of Compost Obtained from Winemaking Byproducts

“…ethanol, acetic acid, lactic acid, polyphenols). Grape marcs can be processed in distilleries to produce alcohol or alcoholic beverages, while grape seeds can be used for extraction of oil and hulls can be used as supplement for animal feed [4].…”