Blue, red and white maize as a sustainable resource for production of distilled spirit

The objectives of this research were to explore the potential of blue, red and white maize as sustainable resource for production of distilled spirits and to study the effect and interaction of yeast strains and maize variety on alcohol yield and formation of volatile compounds that are related to the flavor quality. Four maize varieties (yellow, white, blue, and red maize) and four yeast strains (GR-2, DADY, HG-1, and USW-6) were used for distilled spirit production. Blue maize had the highest average alcohol yield (-90%) and alcohol concentration (12.6%) among the four maize verities. The fermentation efficiency of red maize (89%) was similar to yellow maize (89.3%), while white maize (85.9) was lower than yellow maize. The average alcohol concentration of white maize (11.9%) was similar to yellow maize (12.0%), while red maize (11.5%) was lower that yellow maize. These results show that blue, red and white maize, especially blue maize, are also sustainable resource for spirit production. The type of yeast strains also had significant effect on alcohol yield and concentration. GR-2 ach-ieved consistently the highest average alcohol concentration (12.12%, v/v) and highest alcohol yield (90.16%) regardless of maize variety. HG-1 and USW-6 yielded the similar average alcohol concentration (-11.94%) and yield (-88.35%). DADY had the lowest average alcohol concentration (11.84%) and yield (87.62%) among the four yeast strains. Alcohol fermentation also produces other metabolites such as glycerol and lactic acid as the two major byproducts. For all conditions, the lactic acid level was less than 0.1% (v/v) and glycerol level was less than 1.5% (v/v). 1-Butanol, 3-methyl, ethyl octanoate, and ethyl tridecanoate are the indicators of volatile flavor compounds identified in maize raw spirit distillates. These flavors produce maize spirits' distinctive alcohol, fruity, sweet, and floral flavor profile.