Comparison of antioxidant activity of exopolysaccharides between Lactobacillus acidophilus La and Bifidobacterium adolescentis Ba in vitro

In order to identify the relationship between antioxidant property of exopolysaccharide (EPS) and composition as well as concentration, the study compared the antioxidant activity of EPS between L. acidophilus La and B. adolescentis Ba in vitro. Firstly, the carbohydrate composition of LaP and BaP were quantified by high performance liquid chromatography (HPLC) equipped with a RI detector. The antioxidant activities of EPS estimated included DPPH radical-scavenging activity, linoleic acid peroxidation, ferrous ion chelating effects, and reducing power. The results revealed all the indications of antioxidant property of BaP were significantly stronger than that of LaP (P< 0.05). Moreover, the antioxidant property of BaP was positively correlated with the composition concentration including phenolic content of powerful antioxidant. Therefore, the comparison of composition and concentration of EPS not only could distinguish the antioxidant activity between LaP and BaP, but also made EPS acquire different functionality from composition and concentration. Thus, BaP with more antioxidant potential may merit the potential application of food additives and supplements to the health-promoting food industry.