Study On Extraction, Purification, Stability And Application Of Pigment From Jujube

Natural pigments,on the safe and reliable side,can gradually replace synthetic pigments and become the main food pigments.The pigment extracts from Jujube is a natural pigment,which can increase the kinds of natural pigment and crop economy.This paper systematically studied the extraction,purification,stability and application of pigment from Jujube.The study laid theoretical foundation for large-scale extraction and purification of pigment from Jujube.The Jujube pigment was extracted by two methods of resolve extraction and ultrasonic.The optimal resolve extraction conditions was as follow: particle sizes 40,0.2mon/LNaOH,ratios of solvent to material 20:1 .extract three times and each time for 180 minutes with 80℃,the extraction rate is 95.98%; The optimal ultrasonic extraction conditions was as follow:extraction power 60W, ratios of solvent to material 20:1,extract two times and each time for 45 minutes with 60℃,the extraction rate is 94.58%.Ultrasonic extraction rate is less little than resolve extraction, but more color value and save plenty more time.The result of purification was as follows:S-8 is better than the other 6 resins.while 1ml/min as the flow rate on adsorption,2ml/min as the flow rate on desorption , adsorption and desorption at normal temperature , the optimal adsorption is 0.2mol/LNaOH.Purification under these conditions,the yield is 6.36%,pigment colourity enhanced 10times.The result of studying on pigment stability showed that, the pigment was stable against to night,temperature and alkaline condition;Some metal ions,such as K+,Ca2+,Na+,Mg2+,Zn2+ had little influence on the stability of pigment,but other ions such as Cu2+,A13+,Fe3+ destroy its stability,and K+,Ca2+,Na+,Mg2+,Zn2+ can protect the extracted colorant.H2O2 in low concentration effected the pigment's stability little;citric acid and ascorbic acid decreased the pigment's stability obviously;the pigment was stable against to Na2SO3,sweetner and preservative substance.Color reaction,ultraviolet-visible and infrared spectrum result showed that the Jujube pigment is flavanone compound and included the following framework:=C-OH,Aromatic ring,C=O.The sterilization and illumination experiments showed that the Jujube red pigment have good application and it will have a excellent prospect.