Microbiological, physicochemical, textural, and rheological properties of fermented soymilk produced with Enterococcus faecium and Lactiplantibacillus plantarum

The selection of appropriate starter cultures is a crucial factor in determining the quality of fermented soymilk products. This study evaluated the effects of a combined starter culture of Enterococcus faecium CGMCC 29309 and Lactiplantibacillus plantarum CGMCC 29306 on the microbiological, physicochemical, textural and rheological characteristics of fermented soymilk. The results indicated that the mixed-strain fermentation significantly increased the concentrations of free isoflavones, free amino acids, free fatty acids, and aroma compound acetaldehyde, 2,3-butanedione and acetoin, and significantly reduced the level of beany compound hexanal. The fermentation also greatly improved the textural and rheological characteristics of fermented soymilk. The Enterococcus faecium strain played a leading role in the mixed-strain fermentation, whereas the Lactiplantibacillus plantarum strain was found to be necessary due to its greater ability to break down conjugated isoflavones. This study provides a theoretical basis for using the combined lactic acid bacteria starter to prepare premium fermented soymilk products. [Display omitted] •Mixed fermentation boosts aroma compounds in fermented soymilk.•Mixed fermentation lowers hexanal levels in fermented soymilk.•Mixed fermentation improves texture, and viscosity properties of the products.•E. faecium CGMCC 29309 produces more amount of free fatty acids.•Lpb. plantarum CGMCC 29306 excels at hydrolyzing isoflavone conjugates.