基于有机酸代谢的优势乳酸菌发酵番茄酸汤特征风味形成机理研究

苗族酸汤是深受消费者喜爱的传统发酵食品。酸味是决定酸汤风味品质的第一要素。但酸汤多沿用传统工艺，发酵周期长，质量难保证。本课题针对酸汤自然发酵产酸慢及成熟时间长的“瓶颈”问题，以贵州苗族传统酸汤为试材，应用高通量测序技术探明酸汤发酵微生物群落结构及变化规律并预测功能基因；以糖激酶、脱羧酶、脱氢酶等关键酶为指标，筛选高酶活核心功能乳酸菌制备菌剂；通过番茄发酵前后有机酸变化及传统酸汤风味和滋味成分分析，集成转录组和代谢组学技术，明确酸汤特征风味成分；以有机酸生成和转化为切入点，剖析功能菌发酵番茄特征代谢标志物、关键酶基因表达及酸汤特征风味成分交互关联、构建关联图谱；进而解析以番茄为基质功能菌产酸形成酸汤特征风味的主要生化途径，明确关键要素构建酸汤特征风味形成机制图谱，诠释基于有机酸代谢的优势乳酸菌发酵番茄酸汤风味形成机理，为缩短酸汤发酵周期、优化酸汤品质和质量控制提供新思路和科学基础支撑。

Traditional Miao nationality fermented sour tomato soup is welcomed popularly by consumers. Sour is the first element determined the flavor and quality of sour tomato soup. However, its production is always uses traditional handicraft leading to a long fermentation period and uncontrollable quality. In this study, we aim at these bottleneck problems of naturel fermentation with slow acid production and maturation delay, plan to prove the fermented microbial structure and the variation rule of predominant Lactic acid bacteria during the fermentation period and predict functional gene using high-throughput sequencing technology; screen key strains to make microbial inoculum according to key enzyme of sugar kinase, decarboxylase and dehydrogenase; by analyzing the changes of organic acid and the flavor component of sour tomato soup before and after fermentation, integrating transcriptome and metabonomics technologies to ascertain the characteristic flavor substance. And then, starting from the organic acid production and conversion, this research will focus on analyzing characteristic metabolism landmark of tomato fermented by LAB, and interaction correlation between the key enzyme genetic expression and characteristic flavor, and building interaction map to illustrate the main biochemistry pathway of formation of tomato sour soup characteristic flavor substance fermented by the LAB strains, determine the critical factors to build formation mechanism and annotation the facilitate mechanism based on organic acid metabolize. The research will provide new method and scientific basis for quality control and shorten fermentation period of sour tomato soup and improve its quality.