Purification, Nature And Antioxidative Activity Of Anthocyanins In Shannong No.1Purple Wheat

Color Wheat is valuable germplasm resources. Due to pigment genes and conventionalwheat genes, it has a good yield stability, anti-heterosexual and regional climate adaptability.So it is the foundation of breeding new wheat with high quality. Many studies had confirmedthat the color wheat bran contains a large number of anthocyanins with higher antioxidantsactivity. The color wheat bran can be used to extract the pigment first and then make use offeed or continue to be used to extract fiber hormone, protein, pentosan and other products.This will make the color wheat utilization, and increase it added value.In this experiment, the raw material was purple wheat breeded by Shandong AgriculturalUniversity. The extraction, purification, stability and oxidation resistance of anthocyaninstechnology were studied. The results are as follows:(1) Study on the extraction of purple wheat bran pigmentThe purple wheat bran pigment is extracted by acidified ethanol method. The bestextraction process is the0.5mol/L hydrochloric acid with the volume fraction of45%ethanolas extraction solvent, solid-liquid ratio1:20, extracted120min at70℃, and extracted twotimes.(2) Study on the purification of purple wheat bran pigmentThrough static adsorption, analytical experiment and dynamic test of7typesmacroporous resin to determine the optimum macroporous resin of purple wheat bran pigmentpurification is HP-20; and then the purification process of purple wheat bran by optimalHP-20is determined through single factor and orthogonal test: control sample liquid pH=2.00,column on the flow rate of1.50mL/min, the eluent of50%ethanol solution, the elution flowrate of0.75mL/min. According to Fuleki T, combined with Bill’s law formula of A=ε bc, thepurity is23.26%, increased by2.71times. The o-divinylbenzene in the purple wheat branpigment was determined by gas chromatography-mass spectrometry (GC-MS). It was notdetected out (LOD was20μg/kg) in conformity with the requirements of our country.(3) Study on the stability of purple wheat bran pigmentStudy the effect of pH, temperature, light, metal ions, redox, food additives on thestability of the purple wheat bran pigment. The results show that pH influence on the stabilityof the pigment is significantly; when temperature is below80℃, it has a little effects on thepigmen stability; so the pigment has the certain light fastness. Mg2+, K+, Al3+have very goodgraces and stable function to this pigment; Zn2+, Fe2+, Ca2+on the stability is not big; Fe3+andCu2+make the pigment absorbance decreasing obviously with precipitation, and obvious changes have taken place in pigment color; salt can make the graces and improve the stabilityof pigment, while cane sugar, citric acid can obviously make it fade.(4) Study on the oxidation resistance of purple wheat bran pigmentTest with ascorbic acid, rutin as control, the linoleic acid oxidation inhibition, and the[DPPH],[OH],[O2-],[NO2-] ion removal effect in vitro antioxidant properties were studied.The results show that the scavenging effects on hydroxyl free radical [OH], superoxide anion[O2-] and nitrite ion [NO2-] is significantly and they can reach89.52%,84.41%,76.32%when the pigment concentration is100μg/mL. The linoleic acid oxidation inhibition is goodand it can reach75.40%when the pigment concentration is100μg/mL. At the same time thepurple wheat bran pigment has some scavenging effect on [DPPH] free radical.