Zhou Xiaojie, Liu Zhiqi, Xie Le, Li Liangyi, Zhou Wenhua, Zhao Liangzhong
College of Food Science and Engineering, Central South University of Forestry and Technology, Changsha 410004, China.
College of Food and Chemical Engineering, Shaoyang University, Shaoyang 422000, China.
Foods. 2022 Jan 25;11(3):341. doi: 10.3390/foods11030341.
Chinese red sour soup is a traditional fermented product famous in the southwestern part of China owing to its distinguished sour and spicy flavor. In the present study, the effect of inoculation of lactic acid bacteria (LAB) on the microbial communities and metabolite contents of the Chinese red sour soup was investigated. Traditional red sour soup was made with tomato and red chilli pepper and a live count (10 CFU/mL) of five bacterial strains (including : : : : ) was added and fermented for 30 days in an incubator at 37 °C. Three replicates were randomly taken at 0 d, 5 d, 10 d, 15 d, 20 d, 25 d and 30 d of fermentation, with a total of 21 sour soup samples. Metabolomic analysis and 16S-rDNA amplicon sequencing of soup samples were performed to determine microbial diversity and metabolite contents. Results revealed that fermentation resulted in the depletion of native bacterial strains as LAB dominated over other microbes, resulting in differences in the relative abundance of bacteria, and types or contents of metabolites. A decrease ( < 0.01) in Shannon and Simpson indices was observed at different fermentation times. The metabolomic analyses revealed a significant increase in the relative content of 10 metabolites (particularly lactic acid, thymine, and ascorbic acid) in fermented samples as compared to the control. The correlation network revealed a positive association of with differentially enriched metabolites including lactic acid, ascorbic acid, and chlorogenic acid, which can desirably contribute to the flavor and quality of the red sour soup.
中国红酸汤是一种传统发酵食品，因其独特的酸辣风味而在中国西南部闻名。在本研究中，研究了接种乳酸菌（LAB）对中国红酸汤微生物群落和代谢产物含量的影响。传统红酸汤由番茄和红辣椒制成，并添加了5种细菌菌株的活菌计数（10 CFU/mL）（包括：：：：），在37℃的培养箱中发酵30天。在发酵的0天、5天、10天、15天、20天、25天和30天随机抽取三个重复样本，共21个酸汤样本。对汤样本进行代谢组学分析和16S-rDNA扩增子测序，以确定微生物多样性和代谢产物含量。结果表明，发酵导致原生细菌菌株减少，因为乳酸菌在其他微生物中占主导地位，导致细菌相对丰度、代谢产物类型或含量出现差异。在不同发酵时间观察到香农指数和辛普森指数下降（<0.01）。代谢组学分析显示，与对照相比，发酵样本中10种代谢产物（特别是乳酸、胸腺嘧啶和抗坏血酸）的相对含量显著增加。相关网络显示，与差异富集的代谢产物（包括乳酸、抗坏血酸和绿原酸）呈正相关，这有望对红酸汤的风味和品质做出贡献。
