Study On Extraction,Isolation And Purification,Activities Of Black Rice Anthocyanins

Black rice is an important function of rice resources due to widely grown in our country,especially in northern China is gradually expanding its acreage.Natural pigment-anthocyanin rich in black rice seed coat as an important source of natural antioxidants has significant antioxidation,anti-tumor and other important health functions,As widely used in health food processing,therefore it has been a high application value and development prospects.This test was to research the extraction and purification technology of anthocyanins from the northeast three provinces of black rice as raw material,the structure,antioxidant activity and antibacterial activity of the three provinces of black rice anthocyanins were identified,compared and analysed preliminarily,the main findings are as follows:1.Optimization of extraction processes of the anthocyaninAccording to single factor experimental results,The optimum parameters of the ultrasonic assisted extraction process of black rice anthocyanin were determined by rotatable central composite experimental design and response surface analysis are:solvent:75%ethanol,ultrasonic time:26.50min,ultrasonic temperature:51?,ratio of material and solvent:1:11.So the black anthocyanin content was 2.09mg/g which was close to the predictive value of 2.14mg/g.2.Purification and preliminary identification of black rice anthocyaninsBy comparing the adsorption rate and the desorption rate of 5 kind of macroporous resins on purifying anthocyanin from black rice,the macroporous resins with best purification effect was AB-8.The optimum purification conditions were determined by adsorption and desorption test of static and dynamic:adsorption time:3h,adsorption pH:2.0,desorption time:1.5h,desorption solvent:60%ethanol,both the adsorption and desorption flow rate were:1.0ml/mL,and the sample concentration:0.5mg/mL.The pigments were judged for flavonoids by color reaction,and further judgement were anthocyanins by TCL,UV and IR.3.Investigation antioxidant activity of black rice anthocyaninsWith the crude and purified extracts of black rice anthocyanins were made to scavenging radicals and compared,and Vc as the contrast.The following conclusions:both crude and purified anthocyanins were with variety of degrees of scavenging effect in three kinds of radical,but also with the ability of anti-liposome.The purification of black rice anthocyanin in Heilongjiang had strong free radical scavenging ability,and the scavenging rate for DPPH,OH and O2-were 90.98%,72.79%and 66.26%.Respectively,while black rice anthocyanin in Jilin had a strong anti-liposome ability,purified extracts inhibition rate was up to 47.60%.4.Investigation antibacterial activity of black rice anthocyaninsStudy on the antibacterial activity of black rice anthocyanins in Heilongjiang,Jilin and Liaoning to several different bacterial straidifferent ns,then the following conclusions were compared and got:through the comparison with origin of black rice anthocyanins on bacteria and mold antibacterial activity,Heilongjiang black rice anthocyanins were obtained to study on Escherichia coli,Staphylococcus aureus and Aspergillus niger inhibition,on Bacillus subtilis,Penicillium and Rhizopus was also effect,its bacteriostasis effect were better than Jilin and Liaoning black rice anthocyanins.