Prebiotic effects of citrus pectic oligosaccharides.

Citrus peel wastes, one of the major by-products of the agri-food industry, are a source of value-added compounds. In this work, a commercial pectin (PEC1) and one obtained by direct extraction from citrus fibre (PEC2), were hydrolysed and ultrafiltered at different cut-off (100, 50 and 30 kDa) and then tested in broth with four different probiotic strains: Lacticaseibacillus paracasei, Limosilactobacillus fermentum, Lacticaseibacillus rhamnosus and Bifidobacterium animalis subsp. paracasei. In addition, the probiotic strains selected for their growth rate with the fractions of the two pectins were tested for tolerance to different pH values and bile salts. This study demonstrated that POS2 (product from the enzymatic hydrolysis by PEC2) showed greater prebiotic activity than POS1 (product from the enzymatic hydrolysis by PEC1). The results confirmed that citrus pectic oligosaccharides could be used as emerging prebiotics with improved properties due to their antimicrobial and modulating-microbiota ability.