Effect of ultrasound-assisted fermentation on physicochemical properties and volatile flavor compounds of Chinese rice wine

The traditional fermentation method for Chinese rice wine (RW) production has some limitations such as difficulty in controlling quality, long brewing time, and thin taste. In this study, ultrasonic technology was adopted by adding enzyme with the aim of improving the fermentation efficiency and volatile flavor quality of RW. Results showed that the ethanol yield was increased by 23.53 % and the fermentation time was reduced by nearly 2 days by ultrasonic treatment of (one-time, 28 kHz, 1 h, 35 W/L) on the first day. Flavor analysis (following the ultrasonic treatment) showed that the flavors, especially the esters and alcohols in RW, also enhanced most significantly. The contents of isobutyl acetate, ethyl butyrate, ethyl hexanoate, and phenethyl acetate increased by 58.03 %, 107.70 %, 31.84 %, and 18.71 %, respectively. The results showed that the brewing process could be simplified, brewing time could be reduced and volatile flavor of RW could be improved by ultrasound.