萝卜红色素的稳定性和抗氧化性研究

Stability and Antioxidant Activity of Radish Red Pigment

萝卜红色素具有良好的稳定性,自然光和紫外光下均能保持稳定。低于80℃色素分解缓慢,100℃时色素分解明显加快,4h损失率达到50%。低pH值有利于色素的稳定,能耐更高的温度。金属离子对色素的稳定性影响显著,其中Fe2+和Fe3+有利于色素的稳定,但是容易和色素产生络合沉淀,Zn2+、Cu2+、Al 3+使色素稳定性下降,促进色素的分解,Mg2+对色素的影响则不明显。抗氧化实验发现色素具有良好的清除自由基能力,对超氧阴离子、OH·和DPPH·的半自由基清除率(IC50)分别为0.31g/L、0.13g/L和9mg/L,总体抗氧化能力略强于抗坏血酸。

Stability studies show that radish red pigment can remain stable under natural light and ultraviolet light.When it is below 80℃,pigment decomposed slowly.pigment decomposition accelerated significantly at 100℃.Loss rate reached 50% after 4hours＇ heating.Low pH is conducive to the stability of pigment and the capability of higher temperature.Metal ions are significant to the stability of pigment,among which Fe^2＋and Fe3＋are conducive to the stability of pigment,but they are easy to produce complex precipitation with pigment;Zn^2＋,Cu^2＋,Al^3＋decrease the pigment stability and promote the pigment decomposition;Mg^2＋has no effect on pigment.Antioxidant activity studies indicate that pigment has a good ability to scavenge free radicals.Half scavenging of superoxide anion,OH· and DPPHradical（IC50） are 0.31mg/mL,0.13mg/mL and 9μg/mL,the antioxidant capacity is slightly stronger than ascorbic acid.