Key Laboratory of Plant Resource Conservation and Germplasm Innovation in Mountainous Region (Ministry of Education), Collaborative Innovation Center for Mountain Ecology & Agro-Bioengineering (CICMEAB), College of Life Sciences/Institute of Agro-bioengineering, Guizhou University, Guiyang 550025, China; Teagasc Food Research Centre, Moorepark, Fermoy, Co.Cork, Ireland.
School of Liquor and Food Engineering, Guizhou University, Guiyang 550025, China.
Food Res Int. 2020 Nov;137:109672. doi: 10.1016/j.foodres.2020.109672. Epub 2020 Sep 17.
Rice-acid is a unique Chinese traditional fermented acid rice soup and its microbial community plays an important role in the formation of flavour compounds. In the study, rice-acid products from high-temperature and low-temperature fermentation methods were selected to analyze the microbial community, organic acids, and volatile flavour compounds (VFCs). The main bacterial and fungal phyla in Chinese traditional fermented rice-acid were determined to be Firmicutes and Ascomycota, including 62 bacterial genera and 57 fungal genera. The dominant bacterial genera were Lactobacillus, Acetobacter, and Prevotella and the dominant fungal genera were Naumovia, Pichia, Candida, and Saccharomyces. Among organic acids in rice-acid, L-lactic acid had the highest concentration, followed by malic acid, acetic acid, citric acid, oxalic acid, and tartaric acid. Volatile flavour compounds had a high contribution to the flavour, including ethyl acetate, ethanol, acetic acid, propanoic acid, 1-octen-3-ol, 2-nonanol, 2-undecanol, propyl propionate, ethyl propanoate, propyl propionate, and 2,3-butanedione. The microorganisms which were closely correlated with key organic acids in rice-acid included Lactobacillus, Acetobacter, Pichia, Candida, Kluyveromyces and Meyerozyma. The microorganisms which were correlated with VFCs included Acetobacter, Prevotella, Kluyveromyces and Saccharomyces. In particular, Lactobacillus, Pichia, Malassezia, Clavispora, Rhizopus and Cystofilobasidium were significantly positively correlated with lactic acid in rice-acid. Kluyveromyces, Saccharomyces and Emericella were significantly positively correlated with ethanol and ethyl acetate. The study provides the basis for improving the quality of rice-acid.
酸饭是一种独特的中国传统发酵酸米汤，其微生物群落对风味化合物的形成起着重要作用。本研究选择了高温和低温发酵方法的酸饭产品来分析微生物群落、有机酸和挥发性风味化合物（VFC）。确定了中国传统发酵酸饭中的主要细菌和真菌门为厚壁菌门和子囊菌门，包括 62 个细菌属和 57 个真菌属。优势细菌属为乳杆菌属、醋酸杆菌属和拟杆菌属，优势真菌属为游动放线菌属、毕赤酵母属、假丝酵母属和酿酒酵母属。在酸饭中的有机酸中，L-乳酸的浓度最高，其次是苹果酸、乙酸、柠檬酸、草酸和酒石酸。挥发性风味化合物对风味有很高的贡献，包括乙酸乙酯、乙醇、乙酸、丙酸、1-辛烯-3-醇、2-壬醇、2-十一烷醇、丙酸丙酯、丙酸乙酯、丙基丙酸酯和 2,3-丁二酮。与酸饭中关键有机酸密切相关的微生物包括乳杆菌属、醋酸杆菌属、毕赤酵母属、假丝酵母属、克鲁维酵母属和梅耶罗氏酵母属。与 VFC 相关的微生物包括醋酸杆菌属、拟杆菌属、克鲁维酵母属和酿酒酵母属。特别是，乳杆菌属、毕赤酵母属、马拉色菌属、枝孢属、根霉属和柱孢属与酸饭中的乳酸呈显著正相关。克鲁维酵母属、酿酒酵母属和青霉菌属与乙醇和乙酸乙酯呈显著正相关。该研究为提高酸饭的质量提供了基础。
