Study On Extraction, Property And Application Of Peanut-skin Red

Food colorants are classified as natural colorants and chemosynthesis colorants. Accordingto its harmless, the natural food colorants are now more attractive to people. This paperstudied the extraction and property of peanut-skin red and its application in carbonatedbeverage.The peanut-skin red was extracted by two different methods, organic solvent extraction andmicrowave extraction respectively. The results showed that the optimum condition of organicsolvent extraction were as follows, solvent: 60% alcohol, temperature: 55℃,extraction time:3.0h, the weight of mixture: 25 folds of the peanut skin. The optimum conditions ofmicrowave extraction were obtained, extraction power: 240W, solvent: 65% alcohol,extraction time: 90s, the weight of mixture: 25 folds of the peanut skin red. There were twostages during the extraction. Comparing with the organic solvent extraction, the microwaveextraction method was timesaving and more efficient, which indicated that it could be avaluable and economic method for the extraction of peanut-skin red.Peanut-skin red contained mainly flavones. It showed that the maximum absorption beamof peanut-skin red was 215nm and 280nm and the product was stable when pH changedamong 1 to 12. It was stable to light and heat. The pigment was not affected by sucrose, citricacid, Ca2+, Mg2+,Cu2+ and Zn2+, while it was significantly influenced by Fe3+. Na2SO3 had noeffect on the pigment, but H2O2 and Vc made it colorless. Its solubility could be reduced byNaCl, K+ and Cu2+.The scavenging activity of peanut-skin red on superoxide anion, hydroxyl free radicals, andits inhibitive ability of lipid peroxidation were studied in this project. The results indicatedthat peanut skin had high antioxidant activity, and seemed to be a promising source of naturalantioxidant.The antibacterial activity of peanut-skin red was studied with K-B method and cuvettemethod. The result showed that, the peanut-skin red had strong antibacterial activity againstbacteria, but had no effect on mold and yeast. The MIC of three kinds of bacteria wasobtained, escheria coli: 0.6mg/ml, stapHylococcus aureus: 0.6mg/ml, baccilus subtilis:0.4mg/ml.Peanut skin red was further applied in carbonated beverage. The carbonated beverage wasyellow, uniform and harmonious. The color of beverage didn't fad, when being kept indarkness or room light. It indicated that peanut skin red was stable in carbonated beverage.