Separation And Purification Of Pumpkin Pectin And Application In Encapsulation Of Hazelnut Oil

Pumpkin has a high edible and nutritional efficacy,but the way of eating is relatively simple,and the development and utilization are relatively few.Pumpkin pectin has the function of preventing and curing diabetes,obesity and high blood fat.At present,high purity pectin is mainly dependent on imports,and its price is much higher than that in China,so it is of great significance to develop high purity pectin.Using pumpkin pectin and chitosan as composite wall material to encapsulate hazelnut oil with high health care value but easy to be oxidized,it can not only protect the health care function of hazelnut oil,but also provide a new idea for comprehensive utilization of pumpkin pectin.This paper tries to develop a new wall material which is composed of pumpkin pectin and chitosan to wrap hazelnut oil with synergistic hypoglycemic effect to prevent it from being oxidized.The morphology,physical properties and stability of microcapsules are observed.The main research contents and results are as follows:1.To pumpkin pectin extraction by enzymatic hydrolysis acid formulation is optimized,with the pumpkin pectin yield as the main index,on the basis of single factor experiments,response surface method is used for the pumpkin pectin extraction of digestion and acid extraction process conditions are optimized,the optimum process conditions for enzyme solution:enzyme concentration is 1.4 mg/g,enzyme solution temperature is 65 ?,enzymolysis time for 60 min,enzyme solution pH value of 4.6,optimal process for acid:the temperature is 70?,for 60 min time,pH value of 2.0 after enzyme solution under the conditions of acid,pumpkin pectin yield of 18.768%.After the separation and purification of crude pectin,the extracted substance was detected by HPLC.The extracted substance consisted of Man,Rib,Rha,Galua,Glu,Cal,Xyl,Ara and Fuc and a few other monosaccharides with the contents of 0.153,0.149,0.732,0.111,4.224,0.533,2.095,1.193,1.000,0.434 mg/g respectively.The relative molecular weight was measured by GPC method,and the four Mw(weight average molecular weight)values were 20.34 million,620,000,1714 and 300..2.Hazelnut oil microcapsules with pumpkin pectin composite wall material were prepared by emulsion polymerization method.The optimal process parameters were optimized by response surface method:emulsifying temperature 70?,emulsifying duration 60 min,composite wall material ratio 1:1,solid content 1.2%,and the encapsulation efficiency of microcapsules was(81.45%±0.63)%.Scanning electron microscopy(SEM)showed that the shape was spherical or elliptical with no cracks on the surface.FT-IR analysis showed that the composite wall material composed of pumpkin pectin and chitosan could be used to embed hazelnut oil,and the encapsulation effect was good.3.The physical and chemical properties of the pumpkin pectin composite wall material hazelnut oil microcapsule were tested.The conclusions were as follows:the surface of the microcapsule was light yellow,without bad odor,the water content is(2.56±0.11)%,and the density is(0.27±0.08)g/cm-3,the angle of repose is(46.52±0.42)°,the solubility is(83.58±0.720%,and the particle size ranges from 6 ?m to 50 ?m.4.The retention rate of hazelnut oil was used as the main measurement index to investigate the storage stability of pumpkin pectin microcapsules under different ambient temperatures(including different temperatures,light and O2).The results showed that different conditions had influence on the stability of microcapsules.The release of core material of microcapsules could be accelerated under high temperature,light and oxygen conditions,and the stability of microcapsules could be improved by vacuum storage at 4? without light.Therefore,microcapsules are suitable for storage at low temperature without oxygen and light.The results of in vitro simulation experiment showed that the release rate of core material in the stomach was 30.48%,and the cumulative release rate in the intestine reached 85.24%,which indicated that the hazelnut oil microcapsule had good sustained-release properties and effectively released most of the oil in the intestine.