Production of sake from local variety of rice using isolated mold from local starter culture, Murcha

Abstract

Rice wine is alcoholic beverage made by simultaneous saccharification and fermentation by using mold and yeast. Rice (Oryza sativa) is staple food for half the world population. In Nepal, local starter culture (Murcha) has been used for starter culture for production of cereal based alcoholic beverage. The quality of alcoholic beverage always varies due to lack of process standardization in term of culture and process. There for an attempt was made to isolate and screen mold and yeast from the murcha collected from different districts of Nepal and used in production of rice wine. The performance of mold was tested for saccharifying capacity. Seven molds isolates from murcha were tested for saccharification by halo zone on starch media, microscopic observation, liquefication and DNS test. All the isolated molds exhibit better growth in YPD media and showed positive result of starch hydrolysis. Among all the isolates the mold isolated from murcha (Rajbiraj) showed better saccharifying capacity than other isolates. It showed 36% saccharifyimg capacity, higher than that of other isolates. The mold which have higher saccharifying capacity is used for production of rice wine. In the rice wine total volume of alcohol was found to be 8%, pH was 3.42, succinic acid was 3.9 mg/L and ester was 11.1 mg/L. The lab prepared rice wine was compared with a commercial rice wine, and found comparable with respect to alcohol content, pH, total acidity and ester content. The essential oils was determined by using GC/MS. Key words: Murcha, saccharification, fermentation, GC/MS, rice wine