Improvement of tomato sour soup fermentation by Lacticaseibacillus casei H1 addition

The effect of Lacticaseibacillus casei H1 inoculation fermentation on the quality characteristics and metabolites of tomato sour soup was evaluated to ascertain determine the substances that improve the quality of tomato sour soup. The trends of the titratable acid, organic acid, and fatty acid contents showed that the inoculation of L. casei H1 accelerates the fermentation process. The sensory evaluation indicated that the tomato sour soup fermented by L. casei H1 was more acceptable than the soup from the spontaneously fermented soup. Further analysis of different metabolites and metabolic pathways found that inoculation of L. casei H1 produced more natural antibacterial substances (hydroxyisocaproic acid), essential polyunsaturated fatty acids (linoleic acid, all cis [6, 9, 12]-linolenic acid), and umami amino acids (L-arginine) (p < .05). Therefore, inoculation with L. casei H1 helped to improve the quality of tomato sour soup. These results provide data support for the use of L. casei H1 as an excellent starter for tomato fermentation. Novelty impact statement Differences of metabolic composition profiles in spontaneous and inoculation fermentation of tomato sour soup were explored. Data support was provided for the use of Lacticaseibacillus casei H1 as an excellent starter for tomato sour soup. The advantages of inoculating the dominant L. casei H1-fermented tomato sour soup were revealed by the differential metabolites and pathway analysis.