The prebiotic and protective effects of buckwheat flour and oat bran on Lactobacillus acidophilus

During conservation, the probiotic bacteria currently used in food industry have been shown to have less viability in the matter of fermented products microbiota and also to present lower levels of colonization and survival in vivo. This study describes a new way of improving the behavior and functionality of Lactobacillus acidophilus - LA 5® commercial strain by using buckwheat flour (Fagopyrum esculentum) and oat bran (Avena sativa) as fermentation ingredients, in view of their high content of bioactive compounds that have a great impact both on fermentation microorganisms and consumers’ health. The effect of these two raw vegetal products on LA 5® strain was studied by cultivation on MRS broth and on milk. The supplementation of the fermentation medium with 4.0% - 6.0% of buckwheat flour or oat bran, respectively, had a positive effect on metabolic activity and viability of lactic acid bacteria. Thus, the rapid decrease of the pH and the increase of the multiplication rate were observed after 6 hours of lactic acid fermentation. Furthermore, the presence of the vegetal substrates substantially improved the cells survival during the storage of the fermented products for 28 days at 4 °C, comparing to samples without supplementation used as control