Studies On The Extraction, Purification And Properties Of Vitis Quinquangularis Rehd Skin Pigment

Pigment is important food additive, and with the people's understanding to toxicity of synthetic pigments and the desire to the natural green food, the demand for natural pigment is increasing. Our country is very rich in wild grapes, and to develop these resources, whether in economic or scientific value is important.The extraction condition of vitis quinquangularis Rehd pigment,the stabilities of pigment,the purification parameters of pigment,and anoxidation activity of pigment had been studied in this paper.The results were summarized as follows:The results of experiment of coloration reaction,and analysis of visible spectrum showed that the vitis quinquangularis Rehd pigment was confirmed as a kind of anthocyanins.In order to research the pigment extraction effect,the two extacting methods:taditional solvent extraction,microwave and ultrasonic extraction were compared in this paper.The factor was optimized by orthogonal design.The optimum extraction parameters of taditional solvent extraction were as following:70% ethanol with 1%HCl(pH=2)as soaking liquid,solvent-to-solid(1:5),extraction 60min at 50℃.The optimum parameters by microwave and ultrasonic extraction were as following:70% ethanol with 1%HCl(pH=2),solvent-to-solid(l:5), ultrasonic power (150W), the power of microwave 60%(540W), the treatment time of microwave 60s, the treatment time of ultrasonic 60s.The effect of microwave and ultrasonic extraction was higher than traditional solvent extraction, The extaction time was clearly reduced,and the toal content of anthocyanins improved by 41%.The result of stability test showed that the sunlight,high temperature,H2O2 and Vc accelerated the degradation of the pigment. Ca2+ had little influence on stabitlity of the pigment. Zn2+, Al3+ could increase the stability of pigment. Fe2+ had some damaging effects.Low concentration of Potassium sorbate and Benzoic Acid had little influence on the stability of pigment. Salt and sucrose had all copigmentation function.The purification of vitis quinquangularis Rehd pigment was studied by macroporous resin.It was proved that the NKAⅡmacroporous resin was the most suitable sorbent among the eight kinds of macroporous resin. Adsorption kinetics of NKAⅡresin by applicating Langmuir equation was studied,and adsorption rate constant of the NKAⅡresin was 0.3369, showing a good choice of adsorption to vitis quinquangularis Rehd pigment. The optimum parameters of static experiment were:adsorption temperature 35℃,desorption temperature from 25℃to35℃,p H 2,adsorption time 5h,desorption time 5h,70% ethanol with 1%HCl(pH=2)as enluent. The optimum parameters of dynamic experiment were:the sample velocity 1.0m 1/min,the adsorptive concentration 1.568mg/mL,the desorption velocity 1.0mL/min,the eluent consumption 9BV.Under the condition mentioned above,the colour value of purified pigment was 4.76 times to that of unpurified.The antioxidation of samples were studied by four different systems.The results showed that vitis quinquangularis Rehd skin pigment had strong antioxidant properties.Remarkable scavenging effects against DPPH·,·OH, O2-·were detected,and at the same concentration, the reducing power of Vc was highest,and purified pigment was higher than unpurified pigment. The deoxidative ability of the pigment increased with the concentration,and the deoxidative ability of purified pigment was higher than unpurified pigment.