Antioxidant activity of some yogurt starter cultures

Several commercial yogurt starter cultures (L. acidophilus LA5, L. casei 01, L. acidophilus LA100, L. bulgaricus LB207 and L. rhamnosus GG744) were investigated for antioxidant activity by using in vitro assays. From the results of the present work, all strains tested showed varying degrees of antioxidant activity. L. bulgaricus LB207 showed the highest antioxidant activity, with a linoleic acid peroxidation inhibition of 81.3%. Hydroxy radical scavenging activity, ferrous iron chelating activity, reducing power and superoxide dismutase (SOD) activity were also studied. L. bulgaricus LB207 showed the highest hydroxy radical scavenging activity and L. casei 01 showed the highest chelating activity. L. bulgaricus LB207 and L. acidophilus LA100 showed good reducing power. All the strains in this study showed low SOD activity. The results of the present work suggest that antioxidant activity of L. bulgaricus LB207 due to its strong hydroxy radical scavenging activity and reducing power.