Abstract:The effects of different koji recipes on the organic acids as flavor substances during the brewing of Hakka rice wine were studied by HPLC. The effects of Monascus on the flavor and total amount of organic acids during brewing were also investigated. The total amount of organic acids in the three wine samples differed significantly on Day 30 after fermentation: the rice wine with the yeast and the koji (wine sample Ⅱ) the highest (33.83 g/L), the wine with Monascus alone (the wine sample III) the second highest (27.72 g/L), and the wine complex with Monascus, yeast and koji (wine sample Ⅰ) the least (22.67 g/L). The ratio of volatile acid to non-volatile acid in the wine samplesⅠ, Ⅱ and Ⅲ were 1:4, 1:1 and 2:1, respectively; The lactic acid content in the wine samples differed largely, with the wine sample I having the highest amount (11.40 g/L), and thewine sample Ⅲ had the least (6.02 g/L); the acetic acid content in the three kinds of wine resembled (about 5.5 g/L); the wine samplesⅠ and Ⅱ had a similar succinic acid content (about 5 g/L); The wine samples Ⅱ and Ⅲ had a relatively high propionic acid content with none detected in wine sample I. In addition, small amounts of malic acid and citric acid were detected in the wine sample I. The results showed that adding an appropriate amount of Monascus during Hakka rice wine brewing would help maintain the acidity balance of Hakka rice wine and enhance the sense of taste.
