New sweet sorghum spirit: yeast inoculum selection, chemical and sensorial characterization

Abstract

Sweet Sorghum is a crop able to store high levels of soluble sugars in its culm and presents processing technology similar to sugarcane, being a promising raw material for use in distilleries in the production of spirit. This study aimed to select an inoculum and sweet sorghum genotype suitable to produce a sweet sorghum distilled spirit considering its volatile compounds profile and sensorial acceptance. Two inocula, only Saccharomyces cerevisiae and another mixed inocula comprising the S. cerevisiae and Meyerozyma caribbica, were tested in a screening test according to their fermentative capacity. Only the inocula and sweet sorghum genotypes that presented the best performance were used in the next phase to produce the distilled beverage. The obtained sweet sorghum spirits were chemically characterized as to their volatile compounds profile by gas chromatography and sensorial characterized by 50 untrained volunteers. Both inocula and the BRS 506 genotype were selected during the screening due to their high ethanol conversion, yield, efficiency and productivity. Fifty-five volatile compounds were identified in both spirits. The sweet sorghum spirit produced with S. cerevisiae resulted in 9249.35±77.75 µg/L of volatiles, being most of them volatile acids, aldehydes and terpenes. On the other hand, the spirit fermented with the mixed inoculum presented a total of 15536.00±0.79 µg/L, being most of the esters and higher alcohols. Overall, regardless of the inocula, sweet sorghum proved to be a promising substrate for a distilled beverage. Even more, the inclusion of M. caribbica as a co-inoculant resulted in the enrichment of the volatile compounds profile and sensorial acceptance of the spirit, mainly in relation to the volunteers’ intention of purchase