Effect of drying methods on nutritional constitutes of fermented grape residue.

One of the biggest hurdles faced by the wine industry is the disposal of residual biomass generated after vinification. Although this residue is biodegradable, it constitutes a potential source of environmental pollutants. To alleviate this issue, this biomass may be used in alternative applications; for example, it may be transformed into an enriched flour that can be used to improve the nutrient content in different foods. In this study, were evaluated the effects of drying processes on the relevant nutritional components in dry extracts obtained from the residue of fermented grape pomace. The concentrations of phenolic compounds and anthocyanins were higher when drying the flour by the traditional oven procedure than by freeze-drying. The highest difference (approximately 40%) was observed for tannin compounds. Therefore, drying in an oven is recommended due to the lower loss of bioactive compounds, in addition to being simple and cheap.