新疆酸马奶中抗氧化益生乳酸菌的筛选

目的:筛选出性状优良、具有抗氧化活性的乳酸菌菌株,为开发具有抗氧化活性的功能性食品提供理论依据。方法:通过菌株对H2O2的耐受能力实验、羟自由基清除实验、还原活性测定实验以及亚铁离子螯合能力测定实验,对28株乳酸菌活细胞体、无细胞提取物以及胞外分泌物的抗氧化能力进行测定。结果:两株益生乳酸菌S3、Y11具有较高的抗氧化能力,对实验所用的不同浓度过氧化氢具有一定的耐受能力;当添加样品量为1.5mL时,两株菌的活细胞体和无细胞提取物对羟自由基的清除率分别为38.1%和25.2%,52.3%和29.7%;两株菌均具有还原活性,A700nm值分别为2.272和3.083;两株菌对亚铁离子(Fe2+)的螯合率分别为36.62%和43.16%。结论:28株乳酸菌菌株的抗氧化能力存在差异,乳酸菌菌体内可能含有较多的起抗氧化作用的活性物质,并筛选出2株具有较强抗氧化能力的乳酸菌菌株。

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.