Native wheat, potato and pea starches and their physically modified preparations tested in vitro as the substrates for selected Bifidobacterium strains

Abstract

The wheat, potato and pea starches subjected to physical modification were studied in vitro as a substrate for selected Bifidobacterium strains (Bifidobacterium breve KN14, Bifidobacterium animalis KS20a1). The effects of these substrates on bifidobacterial growth, acidifying activity, metabolic end-products and changes in starch microstructure were assayed after 24-h fermentation. Physically modified starch preparations were better utilized substrates for growth of Bifidobacterium monocultures, in comparison with native starches. Lactic acid occurred in the highest concentration in the culture of B. breve KN14 (55–104 µmol/100 ml), whereas acetic acid was highest in the culture of B. animalis KS20a1 (329–378 µmol/100 ml). The microstructure pictures showed meaningful differences between native and modified starches stemmed from the enzymatic action of examined Bifidobacterium strains during fermentation. Obtained results confirmed the stimulation of growth and acidifying activity of selected Bifidobacterium strains by investigated physically modified starches in comparison with native starch.