Extraction and Stability of Purple Cabbage Pigment

Purple cabbage under natural,cold and freezing preservation was pretreated,respectively.Then,pigment was extracted from it with ultrasonic method under acidic conditions.The influence of pH value,temperature,preservative concentration and sucrose concentration on the stability of the pigment were studied.The results show that the color of the pigment changes remarkably as the pH value increases,while is steady under weakly acidic and neutral conditions.Temperature has no obvious effect on the color of the pigment.As the content of sodium benzoate increases,the pigment changes gradually from pink color to lilac.The pigment is relatively stable when sodium benzoate content ranges from 0.05% to 0.2%,.Sucrose has no remarkable effect on the color of the pigment.The stability of pigment extracted from samples under different preservation conditions is similar.