Research On Extraction And Isolation Of Polyphenol From Apple Pomace

Apple pomace is rich in our country, and it has a broad prospect to produce apple polyphenol with physiological activity using apple pomace. we take apple pomace as research material in this research, ultrasonic assisted extraction technology was used, and the optimal conditions of polyphenol extraction was determined by response surface methodology design. Apple polyphenol preliminarily purified by Column Chromatography of Macroreticular Resin was isolated by Sephadex LH-20.Solution components were determined by HPLC. The main conclusions of this research were as follows:1. The effects of ultrasonic power , extracting time , temperature , solvent concentration , ratio of solvent to pomace and times on the extraction of polyphenols were investigated. On the base of single factor experiments, Plackett Burman design was applied to study the factors of ultrasonic extraction and screen out the key factors: temperature,alcohol concentration and the extraction of times.2. A second order quadratic equation for polyphenol extraction was built with response surface methodology (RSM) and their corresponding relationships was remarkable, The optimization of technological condition was determined as: temperature 61℃, alcohol concentration 62%,and the extraction of times 2. the maximum value of polyphenols was 1.21g/kg fresh pomace.3. A new method of combining eluate after Sephadex LH-20 Chromatography was determined. Through UV scanning monitoring and OD value, based on the absorbance curve at the absorption maximum, together with Principle of isolation of Sephadex LH-20, combining eluate selectively , it was fast and effective to isolate more pure polyphenol monomers.4. The apple polyphenol was determined by HPLC. the mobile phase were methanal and 1% acetic acid aqueous solution. Gradient elution was used to analyze the solution components.0~8min the concentration of methanal was 0,8~40min the concentration was 35%, after 40min the concentration of methanal was 0. The running time was 45 min. The detective wavelength was 280nm. Column temperature was 30℃. The flow rate was 1.0mL/min. The injection volume was 20μL. Seven polyphenol standards were isolated preferably.5. Based on the combining elute method, apple polyphenol was isolated to five solution components by Sephadex LH-20. Five solution components were determined by HPLC. The results indicated the purity of Hyperin was 91%, and the yield was 0.088g/kg. The purity of caffeic acid was 87%, and the yield was 0.051g/kg.6. The results of HPLC indicated apple polyphenols can be isolated preferably by Sephadex LH-20 Chromatography. The purity of monomers achieved 90%.