Bacterial Inhibition and Antioxidant Activity of Probiotic Yoghurt Developed Using Microbial Isolates from Soymilk

The aim of this study was to investigate the bacterial inhibition and antioxidant activities of probiotic yoghurts developed using microbial isolates from Soymilk. Bacterial inhibitory activity of yoghurt was evaluated against Staphyloccocus aureus, Bacillus subtillis, Escherichia coli and Pseudomonas flourescens by using the disk diffusion method. The yoghurt showed some inhibitory activities against all the organisms tested. Antioxidant activity of yoghurt was measured using three different methods- Diphenyl-1-picryl hydroxyl (DPPH) radical scavenging activity, lipid peroxidase assay and hydroxyl radical scavenging activity against Butylated hydroxyanisole (BHA) as standard. The results showed that probiotic yoghurt exhibits relative high antioxidant activities as compare to BHA. However, by implications this study suggests that probiotic yoghurt has some inhibitory activities against all the bacteria tested, also can be consider among the most promising functional foods for their antioxidant activity and ability to prevent oxidative damage and attendant ageing.