| Pectin,as a plant polysaccharide,is widely existed in the natural plant.It can be used as a thickener,emulsifier,and stabilizer,which take the place of synthetic polymer materials,in food and cosmetics for its good gel properties.The pectin currently available on the market is mostly extracted from the skins of citrus plants,that most of them are highly esterified pectin.However,related studies have found that low-ester pectins are more widely used in the pharmaceutical and food industries.And low ester pectin is not only superior to high ester pectin used as pharmaceutical excipients,but also batter than high ester pectin in pharmacological activities such as hypolipidemic,anti-tumor,and so on.Therefore,the extraction and application of low ester pectin have received more and more attention.In this studiy,the method and process for the extraction of low ester pectin from grape skins was investigated,and its application as a pharmaceutical excipient in preparations was preliminary discussed.The main research contents and results are as follows:1.Study on the extraction method of grape peel pectin.The extraction of grape skin pectin under the same conditions was carried out by pressure extraction method,ultrasonic extraction method and warm leaching extraction method.The pectin yield,the degree of esterification,and the DPPH free radical scavenging rate were compared to evaluate the influence of extraction methods.The results showed the pressure extraction method is most suitable for the extraction of grape skin pectin.2.Study on the extraction process of grape peel pectin.The influence factors such as temperature,time,pressure,ratio of liquid to material and p H on the yield,esterification degree,molecular weight,galacturonic acid content and DPPH radical scavenging rate of the pectin were investigated by single factor experiments.On this basis,taking the yield of pectin and the degree of esterification of pectin as the inspection indexes,the stardust design-response surface method was used to optimize the pressure extraction process of pectin,and the optimal process parameters were determined as: the extraction temperature was 100 °C,the extraction time was 90 min,and the extraction medium pH was 3.0.3.Study on the purification process of grape peel pectin.The AB-8 and D101 macroporous resin was used to purified the pectin.The influence of the volume of the column liquid,the pH of the column liquid,and the flow rate on the adsorption rate and loss rate of the pectin was investigated.On this basis,orthogonal tests were used to optimize the purification process.Experimental result showed AB-8 resin has better decolorization effect and lower pectin loss rate for grape skin pectin.The process parameters were: column volume 8 BV,column solution pH 3.0,flow rate 25 BV/h.The yield of the product obtained by this process is 92.12% and the purity is 87.24%.4.Grape peel pectin quality-oriented inspection.The physical and chemical parameters of the grape skin pectin was tested,and compared with the commercially available citrus low ester pectin.The results showed that the physical and chemical properties of grape skin pectin all met QB2484-2000 pectin standards.5.Application of grape skin pectin in preparations.The pectin is made into a gastric in situ gel and a colon targeted preparation respectively.Taking the shape of the gel and the degree of release of the pectin matrix tablet as evaluation indicators,the effect of grape skin pectin and commercially available citrus pectin on the gelling agent and the matrix tablet was examined.The results showed that the gel preparation prepared from grape skin pectin had good gel properties,and the grape skin pectin skeleton tablets had better release behavior in vitro.The above studies indicate that the extracted grape skin pectin can be used as a substitute for existing commercial pectin,and has a broad market prospect and huge economic benefits. |
