J. Inst. Brew. 113(3), 272-279, 2007Ribosomal intergenic spacer analysis (RISA) and traditional culture-based methods were employed to examine the fungal community of Shaoxing rice wine wheat Qu. Results showed that RISA profiles of total DNA exhibited nine distinguishable bands. By comparison, the RISA fingerprints recovered from enrichment media gave variable patterns containing fewer bands. Bands corresponding to five fungal species detected by RISA of total DNA were also observed in RISA fingerprints from enrichment cultures. A total of twenty-four pure cultures were isolated with media of potato dextrose agar (PDA), Czapek (CPK) and wheat Qu extraction (WQE). A total of eight, eighteen and eleven fungal species and 7.9 × 10 5 cfu /g Qu, 3.0 × 10 5 cfu /g Qu, and 3.9 × 10 6 cfu /g Qu, were isolated using PDA, CPK and WQE media, respectively. Predominance of each representative species did vary with the culture medium. Comparison of ITS sequences of excised RISA bands and recovered pure isolates with those in GenBank database revealed that the representative fungal species in wheat Qu were Absidia corymbifera, Saccharomyces cerevisiae, Rhizopus oryzae, Rhizomucor pusillus, Aspergillus oryzae, Candida tropicalis, Emericella nidulans, Clavispora lusitaniae, Aspergillus fumigatus, Aspergillus niger, Rhizopus microsporus, Pichia guilliermondii and Pichia anomala. Species of Saccharomyces cerevisiae, Candida tropicalis and Rhizopus oryzae detected in the original samples by analysis of RISA were not recovered in any of the three media. In addition, some species recovered from the enrichments were not detected by RISA analysis. Results obtained with culture-based or molecular-based methods clearly confirmed the importance of developing an integrated approach to gain a better understanding of the microbial community in wheat Qu.

The objective of the study was to systematically investigate flavor compounds in Chinese rice wine (CRW) using chromatography technology. In twelve CRW samples, 93 different flavor compounds were detected and identified including 16 alcohols in addition to ethanol, 29 esters, 9 aldehydes, 9 organic acids, 19 amino acids and 11 fatty acids. Statistical analysis by principal component analysis (PCA) indicated that seventeen flavor compounds in Guyue Longshan rice wine made a large contribution to its special flavor. These compounds were benzaldehyde, acetaldehyde, ethyl 2-hydroxy-4-methylvalerate, ethyl butyrate, phenyl ethyl isobutyrate, ethyl benzoate, ethyl phenylacetate, methyl dodecanoate, methyl oleate, ethyl dedecanoate, 1-butanol, 3-ethoxyl-1-propanol, 1-enanthol, dodecanol, lactic acid, fumaric acid and lauric acid.

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