Abstract: To investigate the microbial diversity and quality changes during the fermentation of Huizhou black rice wine, changes in the microbial community structure during the fermentation process were analyzed using high-throughput sequencing. Quality characteristics such as physicochemical indicators, contents of major bioactive substances and antioxidant activity were examined. Additionally, the volatile flavor substances were identified using solid phase microextraction-gas chromatography-mass spectrometry (SPME-GC-MS). The results showed that the diversity of bacterial community increased in Huizhou black rice wine during the fermentation process, and Weissella, Lactococcus, Levilactobacillus, Lacticaseibacillus and Lactiplantibacillus were the predominant genera, whose relative abundance were 32.03%, 16.48%, 10.19%, 7.24% and 3.58%, respectively. The contents of alcohol and total acids increased significantly, and consequently the pH, total sugar and reducing sugar contents decreased significantly throughout the fermentation process. At the end of fermentation, the contents of major active substances such as total phenols, total flavonoids, anthocyanosides and total free amino acids significantly increased to (537.72 ± 12.71), (270.16 ± 6.85), (507.76 ± 3.12), and (7 312.82 ± 97.31) mg/L, respectively. Both 2,2’-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) cation radical and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging capacity and reducing power were also significantly enhanced. It was found that the contents of total phenols, total flavonoids, anthocyanins and free amino acids in Huizhou black rice wine were significantly and positively correlated with its antioxidant activity. A total of 26 volatile components were identified, among which alcohols and esters were the major ones. This study provides the scientific basis for optimizing the fermentation process of Huizhou black rice wine to enhance its flavor quality.

Key words: Huizhou black rice wine; microbial diversity; quality characteristics; volatile flavor substances; correlation analysis