Study On The Extraction And Purification Of Chlorogenic Acid From Dandelion And Its Main Evaluation

In this dissertation,the extraction separation,purification process of chlorogenic acid form dandelion and the main function was evaluated.The following main research work had been completed,and obtained the following main results:The extraction methods and the technology parameters optimization research.The yield of chlorogenic acid wans used as an index.The best method for to determine chlorogenic acid in dandelion was to compare and analyze the ultrasonic method,enzymatic method and ultrasonic enzymatic hydrolysis method,the best method to determine chlorogenic acid in dandelion is ultrasonic enzymatic hydrolysis.On the basis of single factor experiment,the response surface test was used to optimize,the optimal extraction condition was obtained:cellulase additive amount 0.3%(percentage of dry material,enzyme activity 597U/g),enzymolysis time 1.0h,enzymolysis temperature 50?,pH4.0,ultrasonic power 163W,ultrasonic time 1.7h and solid-liquid ratio 1:20.On this extracting condition,the yield of chlorogenic acid was 2.14%,it was similar to the model predictive value 2.12%Study on the purification process optimization of Dandelion chlorogenic acid.Firstly,the crude eatraction of chlorogenic acid was purificated by aqueous two-phase sestem,and the optimal condition was obtained by single factor and corresponding surface experiments:the mass fraction of acetone was 36%,the mass fraction of dipotassium hydrogen phosphate was 17%,the pH was 4.0.On this condition,the chlorogenic acid purity was up to 55.44%,chlorogenic acid was purified with polyamide resin,and obtained the optimal conditions via optimization experiments:the concentration of sample was 4.0mg/mL,the concentration of sample speed was 4.5BV/h,the pH value was 3.5;the optimum elution condition was that the concentration of ethanol was 55%,the eluen speed was 3BV/h,the eluen dosage was 4.5BV,the final purity of chlorogenic acid was 67.23%,the recovery rate was 89.35%Study on the main functionality of chlorogenic acid in dandelion.The results of antibacterial activity studies were as follow:Chlorogenic acid has antibacterial activity against Aspergillus niger,Escherichia coli and Staphylococcus aureus,the lowest inhibitory concentra-tions were 18 mg/mL,12 mg/mL and 10 mg/mL,respectively.Respectively,Studies of antioxidant and anti-inflammatory properties were as follow:The scavenging effect of chlorogenic acid and Vc at the same concentration was similar,which proved that chlorogenic acid had definite antioxidant activity.Moreover,investigated the effect of chlorogenic acid on xylene-induced mouse ear swelling to inhibit inflammation,the results showed that chlorogenic acid had anti-inflammatory properties,and the anti-inflammatory effect was proportional to the concentration of chlorogenic acid.Development of dandelion functional yogurt.The best ratio of yogurt is:the inoculation amount was 6%(Bulgaricus:Streptococcus thermophilus was 1:1),the amount of chlorogenic acid was 0.2mg,the amount of sucrose added was 9%,and the amount of gelatin added was 0.4%.Compared with ordinary yogurt,dandelion yogurt had a strong antioxidant.The fat content 6.8±0.5 g/100g,non-fat milk solids 11.9±1.0 g/100g,and protein in the finished yogurt were 5.0±0.3g/100g,acidity 79.4±3.1°T,lactic acid bacteria count(1.4±0.06)×109(CFU/mL).