Study on the stability of onion pigment extracted by alcohol

Onion pigment was extracted by 75% ethanol,and then the effects of pH,temperature,light,oxidation and reducing agent、metal ions and food additives on its stability were studied in this paper.The result showed that the onion pigment was stable in acidic conditions;it was stable against to heat treatment;but it was unstable when exposed to sunlight neither nor ultraviolet;oxidation had little influence on the stability of onion pigment,but reducing agent had influence on it,especially Na2SO3andascorbic acid;some metal ions,such as K+,Ca2+,Mg2+,Al3+had little influence on the stability of onion pigment,but other ions such as Cu2+,Zn2+,Fe2+,Fe3+destroy its stability;the onion pigment was stable against to food additives.