林蛙卵黑色素稳定性的研究

采用紫外—可见分光光度法,研究了温度、光照、氧化剂、还原剂、金属离子和食品添加剂对林蛙卵黑色素稳定性的影响。试验结果表明:林蛙卵黑色素具有良好的耐热性和光稳定性,其中氧化剂、还原剂对其影响较大,当KMn O4质量浓度达到50 g/L时,色价保存率降到41.3%,当Na2SO3质量浓度达到50 g/L时,放置48 h,色价保存率降到41.2%;金属离子中,Fe3+对林蛙卵黑色素影响较大,其色价保存率为(13.4±0.2)%,其他金属离子对其影响较小,影响程度排序为Ca2+﹤Na+﹤Zn2+﹤Mg2+﹤Al3+﹤Cu2+Fe3+;蔗糖、葡萄糖、淀粉对林蛙卵黑色素的稳定性无影响,抗坏血酸和柠檬酸对林蛙卵黑色素的稳定性影响较小。

Stability of Melanin Extracted from Brown Frog Eggs

Effects of temperature,light,oxidants,reducing agents,mental ions and food additives on stability of brown frog eggs melanin were investigated by ultraviolet and visible spectrophotometer.The results indicate that melanin has favorable heat resistance and light stability.Oxidants and reducing agents had great effects on melanin.Preservation rate of color value decreased to 41.3％ when KMnO4concentration was up to 50 g/L;Preservation rate of color value decreased to 41.2％ when Na2SO3concentration increased to 50 g/L and brown frog egg was kept for 48 h.Fe3+ greatly affected melanin of brown frog eggs,and preservation rate of color value decreased by 13.4±0.2％.Other ions had smaller effects on melanin,the sequence of whose effect was Ca2~ ＜Na+ ＜Zn2+＜ Mg2+ ＜ Al3+ ＜Cu2+ ＜Fe3+.Sucrose,glucose and starch had no effects on stability of brown frog eggs.While ascorbic acid and citric acid had smaller effects on stability of brown frog eggs.