Evaluation of antioxidant, organic acid, and volatile compounds in coffee pulp wine fermented with native yeasts isolated from coffee cherries.

Abstract

In this study, coffee pulp was examined as a starting material to make alcoholic beverages (coffee pulp wine) and yeast fermentation ability. We have evaluated five yeasts, three of which were previously isolated from the coffee cherry, and the other two were commercial yeasts. The pH, °Brix, viable yeast cells, and color parameters of coffee pulp wines were measured. The antioxidant activity of coffee pulp wine were measured using the 2,2-diphenyl-1-picrylhydrazyl and ferric reducing antioxidant power assays. Relatively, the 2,2-diphenyl-1-picrylhydrazyl inhibition percentage of Saccharomycopsis fibuligera (strain KNU18Y4) fermented coffee pulp wine was higher than that of other yeasts. Coffee pulp wine fermented with Saccharomyces cerevisiae (strain Fermivin) had higher ferric reducing antioxidant power values. Coffee pulp wine fermented with S. fibuligera (strain KNU18Y4) produced higher total phenolic content and total flavonoid content. Coffee pulp wine fermented with S. cerevisiae (strain KNU18Y12) had lower total tannin content compared to other treatments. The citric and malic acid contents were higher in coffee pulp wine fermented with S. cerevisiae (strain Fermivin). On the other hand, high lactic and acetic acid produced, with coffee pulp wine fermented with S. fibuligera (strain KNU18Y4). Ethyl alcohol was the most abundant volatile compound found in all treatments.