紫球藻共生真菌产物中紫红色色素的稳定性及抗氧化性研究

Stability and Antioxidant Activity of Amaranth Pigments Produced by Symbiotic Fungi Isolated from Porphyridium purpureum

采用分光光度法检测紫球藻共生真菌发酵产物紫红色色素的稳定性,考察不同条件对紫红色色素稳定性的影响,并通过清除ABTS及羟基自由基的方法研究了色素的抗氧化性。结果表明:该色素具有良好的光热稳定性,但耐氧化性较差;还原剂Na2SO3对该色素具有增色作用;该色素对大部分金属离子稳定,但对Cu2+、Fe3+敏感;p H对色素稳定性影响较为显著;盐类、糖类食品添加剂对该色素具有护色作用。该色素具有较强的清除ABTS及羟基自由基的能力,对ABTS及羟基自由基的清除率分别为99.69%和80.95%。

The stability and antioxidant activity of amaranth pigments extracted from symbiotic fungi isolated from Porphyridium purpureum were investigated. The stability of the pigment was determined by the change of pigments absorbance value using spectrophotometry,and the antioxidant activity was evaluated using the method of scavenging 2,2 ＇-azino-bis（ 3-ethylbenzo-thiazoline-6-sulfonic acid） diammonium salt（ ABTS） and hydroxyl free radicals. The results showed that the pigments were stable under these conditions such as heating,UV,indoor natural light,Na2SO3,even in the presence of Na Cl,glucose,sucrose,maltose,or metal-ions（ K^＋,Ca^2＋,Mg^2＋ and Zn^2＋）. However,the pigments were bleached by H2O2 and even unstable under sunlight,the color of the pigments changed with p H and also changed to brown in the presence of Cu^2＋ or Fe^3＋ ions. Besides,the amaranth pigments showed good antioxidant activity,when the concentration of pigments was 12. 5 mg / m L,the scavenging percentage of ABTS and hydroxyl free radicals reached 99.69% and 80. 95%,respectively.