Department of Agricultural Biotechnology, Center for Food and Bioconvergence, Seoul National University, Seoul, Republic of Korea.
Brain Korea 21 Center for Bio-Health Industry, Division of Animal, Horticultural, and Food Sciences, Chungbuk National University, Cheongju, Republic of Korea.
J Appl Microbiol. 2021 Nov;131(5):2325-2335. doi: 10.1111/jam.15097. Epub 2021 Apr 19.
This study aimed to clarify the cause of quality reduction in Korean sourdough after successive back-slopping.
We investigated the dynamic changes in lactic acid bacteria during the back-slopping process using genetic fingerprinting techniques. During the initial propagation phases, the dominant lactic acid bacteria were Fructilactobacillus sanfranciscensis (<5 log CFU per g sourdough), Latilactobacillus curvatus (9·5 log CFU per g sourdough) and Levilactobacillus brevis (6·5 log CFU per g sourdough). However, after the 11th propagation, F. sanfranciscensis became more prominent (>9·0 log CFU per g sourdough), whereas L. curvatus and L. brevis rapidly decreased. Monitoring these bacteria in the co-culture system revealed that acid-tolerant F. sanfranciscensis rapidly utilized maltose (1·65 g l h ) and produced large amounts of lactic acid, whereas L. brevis and L. curvatus consumed maltose slowly and L. curvatus was poorly tolerant to lactic acid.
The results indicate that competition exists between the lactic acid bacteria in sourdough during the back-slopping process, and microbial succession by acid-tolerant species results in quality reduction of sourdough.
This study uncovered the cause of microbial changes during the propagation of Korean sourdough and proposed a strategy to develop starters to produce high-quality bakery products.
本研究旨在阐明韩国酸面团连续回种后质量下降的原因。
我们使用遗传指纹技术调查了回种过程中乳酸菌的动态变化。在初始繁殖阶段，优势乳酸菌为旧金山乳杆菌（每克酸面团<5 对数 CFU）、卷曲乳杆菌（每克酸面团 9.5 对数 CFU）和短乳杆菌（每克酸面团 6.5 对数 CFU）。然而，在第 11 次繁殖后，旧金山乳杆菌变得更加突出（>9.0 对数 CFU 每克酸面团），而 L. curvatus 和 L. brevis 迅速减少。在共培养系统中监测这些细菌表明，耐酸的旧金山乳杆菌能迅速利用麦芽糖（1.65 g l h）并产生大量乳酸，而 L. brevis 和 L. curvatus 则缓慢消耗麦芽糖，L. curvatus对乳酸的耐受性差。
结果表明，在回种过程中酸面团中的乳酸菌之间存在竞争，耐酸物种的微生物演替导致酸面团质量下降。
本研究揭示了韩国酸面团繁殖过程中微生物变化的原因，并提出了一种开发用于生产高质量烘焙产品的起始剂的策略。
