乳源酵母Pichia fermentans的抗氧化特性

Antioxidant activity of Pichia fermentans isolated from raw milk

摘要:

为得到新的天然抗氧化剂,采用DPPH法和抑制脂质过氧化法对11株来源于牛乳的酵母菌抗氧化活性进行测定,包括他们的完整细胞和无细胞提取物,发现Pichia fermentans BY5有较好的抗氧化活性.分析不同条件下P.fermentans BY5细胞提取物的抗氧化活性,发现培养基的起始pH值、培养时间、培养基种类对酵母菌的抗氧化活性和蛋白质含量影响显著(P<0.05);而抗氧化活性与蛋白质含量显著相关(P<0.01).将酵母BY5在pH6的麦芽培养基中培养2d后清除DPPH活性可达60%;在pH6的YPD培养基中培养4d后抑制脂质过氧化能力达到74%.

Abstract:

To obtain new natural antioxidant,11 yeast strains isolated from raw milk were screened by determining their capability to scavenge 1,1-diphenyl-2 picrylhydrazl (DPPH) free radical and inhibit linoleic acid peroxidation,including their intact cell and cell-free extracts.It was found that Pichia fermentans BY5 showed excellent antioxidant activity.Then its antioxidant activity under different initial pH and incubation time as well as culture media of wort,YPD and PDA was analyzed.The results revealed that all these conditions significantly affected the antioxidant activity (P < 0.05),and the protein contents showed a remarkable correlation with antioxidant capability (P < 0.01).In addition,the capability of scavenging DPPH of BY5 extraction reached 60% when being cultured with initial pH 6 in wort for 2 d,and the inhibition of linoleic acid peroxidation reached 74% in YPD for 4 d.