Screening of antioxidative lactobacillus from Koumiss in Xinjiang

Objective:In order to provide theoretical evidences for developing functional food with antioxidative activity, lactobacillus strains with antioxidative activity were selected.Methods:The antioxidant capabilities of 28 lactobacillus strains of live cells, cell-free extracts and extracellular secretions were determined through H2O2 tolerance capability, scavenging capabilities of hydroxyl free radical, reducing activities and chelation abilities of ferrous ion.Results:S3 and Y11 displayed the excellent antioxidant capabilities among 28 lactobacillus strains.The two desired strains showed excellent tolerance in different concentration of H2O2 in culture media;Scavenging efficiencies of S3 and Y11 cell suspension and cell-free extracts were 38.1%, 25.2%and 52.3%, 29.7% for hydroxyl free radicals when addition level was 1.5mL;The two lactobacillus strains showed good reducing activities, the values of A700nm were 2.272 and 3.083;The percentage of chelating ferrous ion (Fe2+) capacity were 36.62%and 43.16%, respectively.Conclusion:28 lactobacillus strains had different antioxidant capabilities.Antioxidative active substances might exist in lactobacillus live cells, and 2 lactobacillus strains with antioxidative activity were selected.