Effects of Storage Environment and Additives on the Stability of Purple Rice Anthocyanins

Using purple rice anthocyanins as raw materials,the effects of light irradiance,light wavelength range,dissolved oxygen,metal ions and co-pigments on the stability of anthocyanins solution in storage environment were studied. The results showed that there was a significant negative dose-response relationship between the light irradiance and the retention rate of purple rice anthocyanins,and the products rich in anthocyanins should not be stored under strong light. The destructive acceleration experiments related to anthocyanins with strong light were simple and efficient. Both ultraviolet and visible light had destructive effects on anthocyanins,and blue light(450~490 nm)had the most destructive effect. The smaller the wavelength range of visible light incidence,the better the anthocyanins preservation. Reducing dissolved oxygen was the key factor to maintain anthocyanins stability under indoor natural light conditions. Five kinds of metal ions of Zn²⁺,chlorogenic acid and gallic acid had protective and complementary pigment effects on anthocyanins. The wavelength of incident light ranged from 700 to 1000 nm,the dissolved oxygen contents was controlled at 0.2 mg/L,1 mmol/L of Zn²⁺ and gallic acid with a pigment/co-pigment ratio of 1:15 were added,and the anthocyanins retention rate reached 91.12%,28.43% higher than that of the control group,while the packaging materials could be kept perspective.