Alcoholic fermentation of sugarcane juice with kefir granules

Abstract

Sugar cane is the main raw material used in Brazil in alcoholic fermentation and the yeast Saccharomyces cerevisae is the main microorganism used in industrial distillers. However, other microorganisms are also able to produce ethanol using substrates containing sugars. In this work, kefir granules were employed to produce ethanol using sugar cane molasses as substrate. These granules are composed by several microorganisms that include bacteria (lactobacilli) and yeasts (Saccharomyces, Kluyermyces, Candida and Pichia). Kefir granules are traditionally used to produce fermented milk with low alcohol content. The production of alcoholic beverages using kefir granules was never studied before. Using a factorial design we can observe the influence of the sugar concentration and the initial biomass in the ethanol yield for the fermentation using kefir granules and baker’s yeast (Saccharomyces cerevisae). In spite of the obtained product with kefir presented higher levels of residual sugars and lower ethanol levels, the obtained fermented broth using kefir presented a pleasure and unique odor than the one obtained using baker’s yeast. The Process with kefir showed good potential to produce potable alcohol (sugar cane spirits).