Abstract:

Stability of lac red pigment was investigated under various conditions. Results suggested that lac red pigment had excellent stability to light and heat. Preservation rate of lac red pigment was higher than 95% at outdoor sunlight for 28 days. Excellent stability of lac red pigment was observed in the range of 4－100 ℃ and preservation rate of lac red pigment was higher than 93% after high-temperature treatment for 8 hours. High antioxidant capability of lac red pigment was also determined. Moreover, commonly used food additives had hyperchromic and color retention functions to lac red pigment. Although Fe3+, Fe2+, Ca2+ and Sn2+ damaged the stability of lac red pigment in water, other metal ions did not interrupt its stability. Lac red pigment remained higher preservation rate in acidic environment, however, pH increase resulted in a gradient loss of stability of lac red pigment.

Key words: lac red pigment, lac acid, stability