Physicochemical and microbial properties of Korean traditional rice wine, Makgeolli, supplemented with cucumber during fermentation.

摘要

The physicochemical and microbial properties of Korean traditional rice wine (Makgeolli)supplemented with cucumber during fermentation were investigated. 400 g of cucumber (20% of the total amount of rice) were ground and added to the rice solution (2 kg rice and 3.12 l distilled water) with nuruk (40 g) and yeast (14 g). After mixing the solution, it was fermented for 6 days in a water bath (28 degrees C). During the fermentation, the pH value of the cucumber Makgeolli fell from 5.88 to 3.94 on day 1, and steadily increased to a pH value of 4.48 by day 6. The total acidity of the cucumber Makgeolli sharply increased from 0.02 to 0.20% on day 1, and then slowly increased thereafter to 0.28% by day 6. After the 6th day of fermentation, the L colour values of the control and the cucumber Makgeolli were similar. The total viable cell, lactic acid bacteria and yeast count of the control and the cucumber Makgeolli increased considerably after the 6 days of fermentation. Free sugar analysis showed that glucose contents decreased with increasing fermentation period. The succinic acid content was the highest among all the organic acids. 39 volatile compounds were observed on the final day of fermentation in the cucumber Makgeolli.