臭豆腐卤水发酵过程中微生物变化及 风味成分研究

Study on microbial quantity and flavor components in stinky tofu brine

中文关键词:  臭豆腐卤水  微生物  微固相萃取  风味成分

英文关键词:stinky tofu brine  microorganisms  solid-phase microextraction  flavor components

中文摘要:

      目的 探索臭豆腐卤水标准化生产的可能性。方法 试验了六种不同的发酵配方, 采用混合培养法研究了不同阶段微生物变化, 利用固相微萃取——气质联机的方法测定发酵终了卤水中挥发性成分的差异性。 结果 卤水中微生物的生长由迅速到缓慢, 在发酵成熟阶段相对稳定, 不同配方的卤水中主要微生物指标如细菌总数、酵母菌的数量增长不尽相同。如黄豆加老卤水配方中的酵母菌达到2.4×1013 CFU/mL, 细菌总数为1.1×1014 CFU/mL; 但酸菜水中酵母菌最终仅有2×105 CFU/mL, 细菌总数为4×1013 CFU/mL。而发酵卤水主要气味成分均有吲哚、醇类、酮类、酸类、酯类和少数几种酚类、硫醚类, 6种配方中酯类有5种化合物相同, 酸类4种, 醇类4种, 酮类6种。结论 利用传统自然发酵方式发酵的卤水, 在发酵过程中微生物彼此消长的变化规律, 可能为纯种发酵控制提供依据。臭豆腐的主要气味物质包括酯类、酸类、醇类、酮类、酚类以及吲哚、二甲基二硫、二甲基三硫以及2,3,5,6-四甲基吡嗪等。本实验中的臭豆腐卤水与传统卤水中风味成分相似性说明了达到规范符合大生产要求卤水的可能性,本实验在加工上的差异性有待进一步探究。

英文摘要:

      Objective To explore the possibility of stinky tofu brine standardization production. Methods Six different fermentation formulas were conducted. The variation microorganisms in different stages were investigated by using mixed culture. The volatile components of brine were detected in the end of fermentation by using solid phase micro-extraction. Results The growth rate of microorganisms in the brine changed from fast to slow and relatively remained stable in fermentation mature stage, and the main microorganisms population such as bacteria, lactic acid bacteria and yeast was not the same in different formula of brine, the number of yeast reached 2.4×1013 CFU/mL in the soy plus old brine formula, and total bacterial number was 1.1×1014 CFU/mL, but the yeast number was only 2×105 CFU/mL in sauerkraut water eventually, and total bacterial number was 4×1013 CFU/mL. the main odor components in fermentation brine were indole, alcohols, acids, esters, ketones and a handful of phenol, sulfide, 5 kinds of compounds were the same in esters of 6 different formulas, and 4 kinds were the same in acids, 4 kinds in alcohols and 6 kinds in ketones. Conclusion There is a shift change rule of microbial quantity in the traditional natural fermentation brine during fermentation. This may provide the basis for controlling pure breed fermentation. The main smell of stinky tofu substances including esters, acids, alcohols, ketones, phenols and indole, dimethyl disulfide, dimethyl 3 s and 2,3,5,6 - tetramethyl pyrazine, etc. The similarity of flavor composition between stinky tofu brine in the experiment and the traditional brine illustrates the possibility to reach the specifications conform and the requirements for mass production, the differences of the experiment on the processing needs to be further explored.