Use of Microwave Maceration in Red Winemaking: Effect on Fermentation and Chemical Composition of Red Wines

The objective of this study was to evaluate the effect of microwave treatment of crushed grapes on the yeast population of the must and on the development of alcoholic fermentation, as well as on the extraction of different compounds from the grapes such as polysaccharides and amino acids that can affect the organoleptic quality and stability of the wine. This study demonstrated for the first time the effect of the microwave treatment of grapes on native yeast species and their diversity, producing an increase in fermentation kinetics and a decrease in the lag phase. The microwave treatment produced a positive effect on the extraction of amino acids and polysaccharides from the grapes, resulting in significantly higher amounts of the main amino acids of the must and some major volatile compounds in the treated samples. The polysaccharides most affected by the microwave treatment were the PRAGs, the main polysaccharides liberated from grapes during the maceration.

Automated summary

This study evaluated the effect of microwave treatment on the yeast population, alcoholic fermentation, and extraction of compounds from grapes. Results showed that microwave treatment positively affected yeast species, increasing fermentation kinetics and reducing lag phase. It also enhanced the extraction of amino acids and polysaccharides from grapes, resulting in higher content of major amino acids and volatile compounds in the treated samples. The polysaccharide PRAGs, released from grapes during maceration, was most affected by the microwave treatment.