| Coix seed,known as “the king of gramineous plants”,is one of the typical plants that can be used as medicine and food.It has a strong growing power,a wide growing range and has been increasingly demanded year by year.Not only rich in nutrients,coix seed also has many pharmacological and health care functions owing to its active ingredients.And since there is high polysaccharide content in coix seed,it has an effect on blood sugar decrease,fatigue resistance,antioxidation and improvement of immune activity.Howeve,the coix seed particles are hard and require long time to cook,which results in the inadequate use of polysaccharid active ingredients and limted use of coix seed as food.Therefore,extracting polysaccharide from coix seed has an important economic value.Reasonable allocation and scientific processing by modern technology can not only improve its taste,enrich the varieties of coix seed products,but also make full use of its pharmacological effects and increase its value,so as to create more economic benefits.This experiment uses ultrasonic wave and enzymatic hydrolysis method assisted by microwave to extract coix seed polysaccharide,and the process was optimized by response surface method,Through the DEAE-52 cellulose column chromatography,the coix seed is separated and purified.And the features of the coix seed polysaccharide are studied.In the end,the coix seed polysaccharide chewable tablets are made,and the material proportioning about the process is studied.The results are as follows:(1)Ultrasonic wave and enzymatic hydrolysis method assisted by microwave are used to extract coix seed polysaccharide.On the basis of single factor experiment,the optimum extraction condition is obtained by response surface optimization is as follows: the enzyme solution temperature 46.4?,ultrasonic time 25 min,ultrasonic power 205 w,microwave time 4min,microwave power 615 w.Under the condition,three repeated verification tests get the coarse polysaccharide yield of 17.97%.Compared with the traditional hot water extraction,it increases by 16.64%.Compared with ultrasonic extraction,it increases by 10.69%,and compared with amylase extraction,it increases by 12.36%.(2)Through the DEAE-52 cellulose column chromatography for separation and purification,coix seed polysaccharide get a single main in elution curves;Through the ultraviolet spectrum,there is no absorption peak at 260~280 nm,which proves that after being purified,coix seed polysaccharide excludes nucleic acids and proteins;Through infrared spectrum scanning,there are many polysaccharide substance absorption peaks within the range of 4000~500cm-1;By the peak time in HPLC scanning records,coix seed polysaccharide consists of rhamnose,xylose and arabinose,mannose,glucose and galactose.(3)The clearance about coix seed polysaccharide is studied,which is superoxide anion radical(O2?·),hydroxyl radicals(·OH),and the ability to DPPH· radical oxidation.Results show when the concentration of coix seed polysaccharide fluid is 5 mg/mL,the clearance rate for superoxide anion radical(O2?·)is 44.81%,which is equivalent to half of the antioxidant capacity of VC.The clearance for hydroxyl radicals(·OH)is low,just 10.12%.The clearance for DPPH· radical antioxidant is next to VC,and the clearance rate was 29.25%.With the increase of concentration,the antioxidant ability increases.(4)Coix seed polysaccharide chewable tablets are made by powder pressing directly,the best process conditions about accessories matching in the chewable tablets are optimized.On the basis of single factor,response surface is used to optimize process.Optimum technological conditions for optimized yield: 55% coix seed coarse polysaccharide powder,25% edible starch,9% lactose,9.98% microcrystalline cellulose,0.67% magnesium stearate,0.75% powder silica gel.Under this condition,the chewable tablets yield is 91.78%. |
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