Studies On Extraction,Purification, Stability And Antioxidant Activity Of Anthocyaninsf From Raspberry

Anthocyanins is a kind of nature pigment. It is reported that anthocyanins have various nutritional functions. Such as rich, safe, non-toxic, edible, nutrition and medicinal value. Anthocyanins had huge development potential in the field of food and medicine, also as a kind of important food additives. The anthocyanins of raspberry content high nutritional value, extraction and purification. Producting the juice and wine, the anthocyanins of raspberry content high nutritional value, extraction and purification. Extraction and purification from raspberry had stability, high health, care value of food additives, material sources, low cost and the advantage of wide prospect of market.This thesis used raspberry as material. The optimal parameters of extracting anthocyanins from raspberry by ultrasonic wave, the purification parameters of anthocyanins by macroporous resin and the stability of anthocyanins were studied. These above studies can provide references for exploration and application of the use of raspberry.The results were as follows:The results from single-factor and orthogonal experiments showed the concentration of ethanol was 60%and the optimal temperature for extraction was 50? and the pH was 0.5.Within the scope of orthogonal experiment, the temperature has a significant effect on anthocyanins of the raspberry.AB-8 macroporous resin had good resolution and adsorption for the anthocyanins of raspberry. The static adsorption was 2.0h.The adsorption resin dynamic adsorption condition were as follows:liquid flow rate of 2BV/h, the pH value 2.0, anthocyanins concentration of 0.4mg/ml.The ethanol concentration was 95%.The stability test of anthocyanins from raspberry with different pH had different visible, Under low temperature, the anthocyanins of raspberry is stable and the thermal degradation speed slow. Sucrose, glucose, Na+' K+, Zn2+ had no influence on the stability.H2O2,Fe3+, Fe2+had great influence on the stability of anthocyanins from raspberry.The results showed that, anthocyanins in raspberry had antioxidant activity, DPPH free radical scavenging activity(71.4%),and.OH free radical scavenging activity(78%).