Exiraciton And Puriifcation Of Pigment From Solmwntuberdsrh

This paper researches the technology of extraction and purification of the purplesweet potato anthocyanins pigment: optimizes the technology of extraction, conductsthe tentative purification and concentration by the membrane technology, and refinesthe pigment solution by the macroporous adsorption resin, then gets the pigment powderby freeze-drying after the rotary vacuum evaporator. The test results will provide thebasic data for the industrial designing.In order to keep the biological activity of the purple sweet potato anthocyaninspigment, this paper makes the technology of extraction in the condition of normaltemperature and acid, the extraction agent is hydrochloric acid aqueous solution, thesolid-liquid ratio is1:3, the pH value of the extraction agent is3, the technology processis marinating for1hour, mixing and extracting for2hours, the whole process not onlyhas low power consumption, but also can extracts effectively the pigment solution.The crude extract of the purple sweet potato anthocyanins pigment is sublimatedtentatively by microfiltration membrane, and the microfiltration membrane caneliminate effectively the protein molecules, the suspended particles, the starch and otherimpurities in solution. The filtrate of the microfiltration membrane is concentrated bythe nanofiltration membrane in the condition of normal temperature and the1.5MPa-operating pressure, the retention rate of pigment is100%, the concentrationratio can reach10times.In order to further sublimate the pigment, this paper adopts AB-8,X-5,HPD-100and PDA-100these four kinds of polymeric adsorbent,and researches their respectiveadsorption and desorption effect on the purple sweet potato anthocyanins pigment, andfinally selects the AB-8-polymeric adsorbent which has higher adsorptivity and betterdesorption rate to refine the concentrate of the purple sweet potato anthocyaninspigment. Conduct the static adsorption test to confirm that the temperature has no effecton the adsorptivity of AB-8-polymeric adsorbent, the peracid condition reduces theadsorptivity, and with the decrease of the concentration of the pigment solution, theadsorptivity of AB-8-polymeric adsorbent increase. Conduct the dynamic adsorptiontest to confirm that the best elution speed is1.0BV/h and when use the ethanol solution which four times the polymeric adsorbent volume and30%concentration, the elution isbetter.Use the vacuum rotary evaporation instrument to concentrate the eluant of thepurple sweet potato anthocyanins pigment which refined by the polymeric adsorbent,and then freeze-drying the pigment concentrate, the color scale of the final pigmentpowder can reach50.This paper also researches the property of the purple sweet potato anthocyaninspigment, conduct the test to confirm the following properties: this pigment is thewater-solubility pigment, in the acidic conditions it is the most stable, and presentmagenta, in the alkaline conditions it is less stable, and present cyan; this pigment issensitive to the temperature, UV-light, metal ion and the reductant-oxidant,inexperiment and production should be paid attention；the usual food additive have littleeffect on stability of the pigment, so they can be used together in the processing.