A research on extraction of the brown pigment from Euphoria Longan seed and its stability
ZHU Chun, WANG Haiyan, CHEN Qing(Department of Chemistry,Chemistry and Biochemistry College,Guizhou University, Guizhou Guiyang 550025, China)
In order to search and develop more natural edible pigment, this paper is about extracting brown pigment from the seed of Longan. Our researching into the influence made by brown pigment on several foodadditives and making tests of the brown pigment to find its quality of heatendurance, lightendruance, oxidationendurance and reductionendurance. Experimental result show: the extracting can be accomplished by using 60% ethanol. The extraction rate is 20%. The maximum absorb wavelength of brown pigment is 260nm. It has good light resistance, heat resisting property and is watersoluble. Its stability is good when the pH is within 1-8. It has less resistance capability against reducing agent Na2SO3, and has better endurance capability against oxidizing agentH2O2. Food additives such as sucrose, salt and citrate has no effects on the degradation of the brown pigment. Vitamin C can make the color of brown pigment hard.