Soybean extruded by‐products as substrate for obtaining food ingredients containing probiotics

Summary Extruded expeller meal (EEM) was widely used for feed production, but few exploited it as a food ingredient. Solid‐state fermentation (SSF) was applied for obtaining food ingredients (FI) based on EEM containing Lacticaseibacillus casei. The FI were characterised physicochemically and functionally. The effect of the SSF on these characteristics as well as the effect of the expeller matrix on the survival capacity of L. casei in in vitro gastrointestinal digestion and on epithelial adhesion were analysed. In general, the SSF process did not produce significant changes on the nutritional and functional properties studied. Probiotic cells supported in the FI were stable for 42 days showing >106 log (CFU g−1) viable probiotic microorganisms. More than 60% of them survived to gastrointestinal simulated conditions. Expeller matrix interfered the adhesion of L. casei with the epithelium. The FI could be incorporated to a porridge for improving the nutritional profile and providing functionality. Obtaining functional food ingredients from soy expeller by means of L. casei solid state fermentation.