Design of probiotic-fortified food matrices influence their antipathogenic potential

Development of new-age probiotic products based on fruit matrix is a result of emerging evidence that there exists a two-way relationship between phenolic compounds and intestinal biota. However, there is a need to evaluate the efficiency of such matrix and ascertain whether there is any advantage offered by non-conventional, phenolic-rich food matrix like fruit, over more conventional dairy matrices. In the current study, two food matrices were designed based on sea buckthorn and apple juice, supplemented with malt extract (M) and whey protein concentrate (WPC), to improve probiotic viability. The effect of juice matrices fortified with probiotic strains, L. plantarum, L. rhamnosus GG, L. acidophilus and L. casei Shirota on the elimination of enteropathogenic E. coli, Salmonella enteritidis, Shigella dysenteriae and Shigella flexneri from food system was evaluated. The antipathogenic potential of probiotics was strongly influenced by the composition of matrices. Malt supplemented sea buckthorn juice was a superior matrix comparatively and could suppress E. coli, S. enteritidis and S. dysenteriae within one hour of co-incubation. Scanning electron microscopy used to study the structural changes and biocidal action of cell-free extract of probiotic-fortified matrices on the four pathogens revealed swelling, multiple pores and complete disintegration of pathogens.