Abstract:Rice with different polishing degrees shows significant differences in nutritional composition. To explore the effect of rice polishing degree on the flavor quality of enzymatically brewed rice wine, five kinds of rice with different polishing degrees (0, 10%, 20%, 30%, 40%) were used to brew rice wine by enzymatic fermentation. The changes in rice wine flavor quality were analyzed from four aspects: physical and chemical indexes, free amino acids mass concentrations, volatile flavor substances mass concentrations, and sensory evaluation. The results showed that with the increase in rice polishing degree, the ethanol volume fraction and total saccharide mass concentration in the rice wine increased, while the amino acid nitrogen mass concentration decreased. The mass concentrations of both free amino acids and higher alcohols decreased from 1 346.17 mg/L and 4 033 μg/L to 1 063.85 mg/L and 3 119 μg/L, respectively, while the alcohol-to-ester ratio dropped from 1.24 to 0.98, which contributed to an improved flavor profile of the rice wine. The mass concentrations of sulfur-containing amino acids methionine and cysteine decreased by 50.8% and 59.3%, respectively, which helped improve the storage stability and freshness of the rice wine. The mass concentration of isoamyl acetate increased from 254.19 μg/L to 406.91 μg/L, improving the volatile flavor of the rice wine. Finally, sensory evaluation confirmed the above conclusions, revealing that the rice wine brewed from moderately polished rice exhibited richer floral and fruity aromas, with a smoother taste. In summary, moderately increasing the rice polishing degree can effectively improve the aroma and taste of rice wine, thereby enhancing its overall flavor quality.
