Abstract: In order to clarify the effect of enzymatic hydrolysis on the quality of fermented red jujube juice, red jujube juice was hydrolyzed by a combination of pectinase and hemicellulase, fermented by Lactobacillu plantarum and then stored at 4 ℃, and changes in the viable bacterial count, major nutrients and color were investigated at different storage times. The results showed that enzymatic hydrolysis significantly improved the contents of soluble solids and titratable acid in fermented jujube juice as compared with the control. Enzymatic treatment was beneficial to maintaining the contents of ascorbic acid, polyphenol and protein of fermented jujube juice during storage, which were 0.7, 0.28 and 0.58 mg/100 mL higher than those of the control after storage for 28 days, respectively. Additionally, the polysaccharide content was also increased slightly and the color was significantly improved. In addition, the viable number of lactic acid bacteria in fermented jujube juice was increased by enzymatic pretreatment, which was significantly higher than that of the control (0.17 (lg (CFU/mL))) at 28 days of storage. These results showed that the quality of fermented jujube juice could be improved by enzymatic pretreatment before fermentation.

Key words: jujube juice, enzymatic hydrolysis, Lactobacillu plantarum, fermentation, quality