Study Of Extraction And Purification And Antioxidant Activities On The Black Peanut Skin Pigment

The peanut skin was the by-products of peanut processing and it has high value of comprehensive utilization with the merit of huge amount and low price.The output of black peanut has no difference with common peanut,but the nutritional value of black peanut was higher than the common peanut.With the deeper researches of black peanut,it will be helpful to enlarge cultivation area of income of farmers.Furthermore,with the large scale culture of black peanut,there will be a plenty of black peanut skin inevitably.In order to developing the ideal anthocyanins resources,it has very vital significance to study the pigment's structure,properties and stability of black peanut skin.This paper took black peanut skin as the research material,and researched the optimum extraction and purification conditions,and its antioxidant activities and reducing blood lipids level of mice with hyper lipid.Through BOX-Behnken experiment using acid water,the results showed the optimum extractive technique parameters that extraction time was 2 h,extractive temperature was at 80℃,the mixture ratio of the black peanut skin to the extraction agent was 1:50,and to repeat it two times at pH=1.In this optimum condition,the extraction rate can reach above 90%.Compared with several types macro porous resin adsorption,AB-8 was the best choice. Though researching the effect of adsorption rate from several factor,the results showed the optimum purification conditions that pigment samples acidity keeping pH=1～4,the absorbance was about 0.445×10,the desorption solution was 60%to 70%ethanol.The BPSP's anthocyanin content after purification was 3.143%,it was higher than one before purification;the polyphenol and flavonoids content was respectively 40.33%and 52.13%.BPSP was very sensitive to pH,the structure of pigment could change in alkaline conditions,it lost the red color in acidic condition,so we should regulate the pH when we wanted to use.BPSP had heat-resistent activity to a certain extent,it was not effected about 80℃;the light could effect BPSP,we should avoid light when using it;glucose,sugar,salt, sodium benzoate and potassium sorbate had not damage obviously to BPSP,so we could use them at the same time at suitable concentration;ascorbic acid,hydrogen peroxide and NaS₂O₅ could cause the degradation of BPSP to a certain extent,so we could not use them at the same time.This paper researched the scavenging ability on superoxide radical,droxyl and H₂O₂ by fluorescence and chemiluminescence of BPSP.The results showed that BPSP had the scavenging ability,but it is weaker than ascorbix acid a little.Though animal experiment, BPSP could decrease blood lipid level of mice with hyper lipid obviously,and the danger of atherosclerosis.Though intaking suitable BPSP,the content of TC and TG in mice's serum would drop obviously,and the content of HDL-C would rise,and BPSP had anti-atherosclerosis activity in evidence.