Effects of Lactiplantibacillus plantarum with different phenotypic features on the nutrition, flavor, gel properties, and digestion of fermented soymilk

This study evaluated the effects of four previously reported strains of Lactiplantibacillus plantarum (T1, CL80, CSK, and S-1A) with different phenotypic characteristics on the fermentation quality, flavor characteristics, and digestive properties of soy milk. The results showed that all four strains exhibited good gastrointestinal survival and Caco-2 cell adhesion probiotic characteristics. The total free amino acid content of fermented soy milk significantly increased from 27.57 mg/100 g to 41.28 mg/100 g, enriching the soy milk with acidity and increasing the volatile flavor compounds such as acetic acid, decanoic acid, and octanoic acid. The fermentation process effectively reduced the levels of volatile compounds associated with beany off-flavors, including 1-octen-3-ol, 1-nonanol, hexanal, heptanal, 2-octenal, furfural, and trans-2,4-decadienal. The gel texture and rheological analysis indicated that soy milk fermented with the viscous phenotypic strains T1 and CL80 exhibited higher water-holding capacity (95.45%, 93.64%) and apparent viscosity (916.39, 713.78 Pa s). Furthermore, in vitro dynamic digestion demonstrated that soy milk fermented with the viscous phenotypic strains was more easily digested during the gastric phase compared to the non-viscous strains. In the intestinal phase of digestion, soy milk fermented with the ropy phenotypic strains had significantly higher levels of small peptides compared to the non-ropy strains, which facilitated the transfer and absorption of nutrients. This study provides valuable insights into improving the nutritional flavor and digestive properties of soy milk through fermentation using Lactiplantibacillus plantarum strains with different phenotypic characteristics.