Studies On Extraction And Properties Of Red Pigment From Cherries

The red pigments of cherries are anthocyanins. The concentration of anthocyanins in dark-fruited cultivars can reach 350-450mg/100g FW. Anthocyanins have many positive properties, for instance, antioxidation, antimutagenicity, anticarcinogenesis and anti-inflammatory activity.The extraction condition of red pigments from sweet cherries(Van) and the stability to light, heat, pH, metal ion and oxidant were studied, and the properties of free radical scavenging were also researched. The results were summarrized as follow:The optimum extraction condition of the traditional acidified ethanol extraction is 70% ethanol (acidified with HC1), solid- to- solvent ratio (1:5), extracting 90min at 50℃.At this condition, the yield of anthcyanins is the largest.The colourity of the pigment extracts enhanced significantly after purification by Amberlite CG-50 ion-exchange resins. Heat or light can decrease the percent colour retention at different degrees. A certain concentration of ion such as Na⁺, Mg²⁺ have a slight effect on the stability of extracts. The existence of oxidant accelerates the degradation of the pigments. There is a significant linear correlation (R²>0.98, P=0.001) between concentrations of pigments or vitamin C and the DPPH-scavenging activity within the applied concentrations. IC₅₀ values of pigment extract and vitamin C are 13.3μg/mL and 8.7μg/mL, respectively. In ESR assay, pigment extract also showed good properties, and there is a dose-dependent manner between scavenging activity and concentrations of samples. Both pigment extract and vitamin C exhibited stronger activities of attenuating the production of superoxide radical than that of hydroxyl.