Study On Green Technology Of Extraction Of Chlorogenic Acid And Preparation Of Mannan Oligosaccharides From Green Coffee Beans

The green coffee beans as raw material were used to extract chlorogenic acid,and the remaining coffee beans residue to prepare mannan oligosaccharides in the paper.It was a green and comprehensive utilization technology of green coffee beans.There was a biological study on this whole far-reaching prospects for green technology neither in China nor abroad.The dissertation mainly was divided into three parts.Researches on the extraction of chlorogenic acid in green coffee beans,separation and purification of chlorogenic acid,structure characterization and green coffee bean extract weight loss functional test,enzymatic preparation mannan oligosaccharides and membrane separation mannan oligosaccharides in this paper.The results were as follows:1.The extraction and purification processes of chlorogenic acid from green coffee beans were studied.Using the method of hot water extraction,the extraction of chlorogenic acid was repeated three times.On the basis of single-factor experiments,four factors of extraction temperature,solvent pH value,solid / liquid ratio and extraction time were chosen to study using the method of response surface analysis.The quadratic regression model with the response values of chlorogenic acidyield was established by Box-Behnken design.The results showed that the chlorogenic acid yield was significantly affected by the four factors,and the suitable extraction conditions were: temperature 79.75 ?,solvent pH value 2.84,solid / liquid ratio 1:6 and extraction time 3.04 hours.The maximum extraction yield of chlorogenic acid was 92.02%.2.The XDA-8 macroporous resin with the adsorption capacity of35.47 mg/mL was selected in the purification process of chlorogenic acid from green coffee beans.Under the optimum conditions(chlorogenic acid concentration 10 mg/mL,velocity 2 BV/h,elude ethanol concentration70%(v/v),amount 5 BV and velocity 3 BV/h),the chlorogenic acid content was up to 70.85% and the recovery rate to 85.42%.Preparative high performance liquid chromatography(PHPLC)technique was used to separate and purify high purity(95.21%)of chlorogenic acid from green coffee bean extract.The experiment was carried out on the application of weight-losing function in obese rats,the results showed that the control effect of weight,body weight and body fat in rats were significantly.The preparation process of chlorogenic acid was established in the study,that had simple,efficient,environmentally friendly,definite efficacy and good market application prospect.3.On the basis of single-factor experiments,?-mannanase of different sources enzymatic hydrolysis of coffee beans residue of preparing mannan oligosaccharides.The four factors of enzyme dosage,hydrolysis temperature,hydrolysis pH value and hydrolysis time were optimized by orthogonal experiment.?-mannanase produced by Bacillus subtilis was used to hydrolysis of coffee beans residue for preparing mannan oligosaccharides.The results showed that the suitable extraction conditions were: amount of enzyme 300 u/g,enzyme hydrolysis temperature 50 ?,solvent pH value 6 and hydrolysis time 8 hours.Under the optimum process conditions,the yield of mannan oligosaccharides was 52.76%.?-mannanase produced by Aspergillus niger was used to hydrolysis of coffee beans residue for preparing mannan oligosaccharides.The results showed that the suitable extraction conditions were: amount of enzyme 300 u/g,enzyme hydrolysis temperature 45 ?,solvent pH value 7 and hydrolysis time 6 hours.Under the optimum process conditions,the yield of mannan oligosaccharides was 61.01%.Determine?-mannanase produced by Aspergillus niger was used to hydrolysis of coffee beans residue for preparing mannan oligosaccharides,better than?-mannanase produced by Bacillus subtilis.Enzymolysis liquid membrane separation of mannan oligosaccharides relative molecular weight less than 1 kDa average degree of polymerization of 3.21.The average degree of polymerization was 7.46 between 1 KDa and 3 kDa filtrate mannan oligosaccharides.The component and dose of mannan oligosaccharides of enzymolysis liquid after PMP derivatization were mannose 2.78%,galactose 42.58% and arabinose 14.64%.