Comparison of Fermentation Behaviors and Characteristics of Tomato Sour Soup between Natural Fermentation and Dominant Bacteria-Enhanced Fermentation

Abstract

In this study, the correlations between microbial communities with physicochemical properties and volatile flavor compounds (VFCs) during the fermentation of traditional tomato sour soup (CTN) are explored. The results of high-throughput sequencing (HTS) of CTN showed that Lacticaseibacillus (28.67%), Enterobacter (12.37%), and Providencia (12.19%) were the dominant bacteria in the first round of fermentation, while Lacticaseibacillus (50.11%), Enterobacter (13.86%), and Providencia (8.61%) were the dominant bacteria in the second round of fermentation. Additionally, the dominant fungi genera of the first fermentation were Pichia (65.89%) and Geotrichum (30.56%), and the dominant fungi genera of the second fermentation were Pichia (73.68%), Geotrichum (13.99%), and Brettanomyces (5.15%). These results indicate that Lacticaseibacillus is one of the main dominant bacteria in CTN. Then, the dominant strain Lacticaseibacillus casei H1 isolated from CTN was used as a culture to ferment tomato sour soup to monitor dynamic changes in the physicochemical properties and VFCs during enhanced fermentation of tomato sour soup (TN). The physicochemical analysis showed that, compared with CTN, the TN group not only produced acid faster but also had an earlier peak of nitrite and a lower height. The results of the GC–IMS analysis showed that the ester and alcohol contents in the TN group were 1.26 times and 1.8 times that of the CTN group, respectively. Using an O2PLS-DA analysis, 11 bacterial genera and 18 fungal genera were identified as the functional core flora of the CTN group flavor production, further verifying the importance of dominant bacteria for the production of VFCs. This study proved that enhanced fermentation not only shortens the fermentation cycle of tomato sour soup, but also significantly improves its flavor quality, which has great value in the industrial production of tomato sour soup and in the development of a vegetable fermentation starter.

Effects of post-fermentation on the flavor compounds formation in red sour soup

“…Meanwhile, the diversity of LAB may also contribute to the production of volatile flavored compounds ( 13 ). As shown in Figure 3 , LAB is the main bacteria in RSS in the post-fermentation process, consistent with sour soup’s widely reported microbial composition ( 4 , 12 , 13 , 31 , 32 , 44 ). Notably, the central populations of LAB are Sporolactobacillus spp., Lentilactobacillus spp., Lactiplantibacillus spp., and Lactobacillus spp.…”

Improvement of physicochemical properties and flavour of pickled radish through the use of a direct‐vat set starter consisting of Lactiplantibacillus plantarum and Leuconostoc mesenteroides

“…Conversely, the levels of other organic acids were comparatively lower. We inferred that the addition of DVS resulted in the dominance of LAB during the fermentation process, leading to enhanced utilisation of nutrients by LAB and subsequent production of lactic acid (Li et al ., 2022b).…”

Effect of Starters on Quality Characteristics of Hongsuantang, a Chinese Traditional Sour Soup

“…These results show that HST fermented with the starter is more fruity, woody, and spicy than uninoculated HST. Li et al [15] proved that enhanced fermentation shortens the fermentation cycle of sour tomato soup and significantly improves its flavor quality, which has great value in the industrial production of sour tomato soup and the development of a vegetable fermentation starter.…”

“…originated in southeast Asia and has been recognized for its characteristic flavor and spice because it contains gingerols and gingerol-related compounds [14]. Li et al [15] analyzed the characteristics of fortified fermented tomato sour soup with dominant bacteria. He et al [16] studied the effects of thermal and non-thermal processing technology on the quality of HST after storage.…”