Extraction, Separation And Determination Of Polyphenol In Banana Peel

Plant polyphenol is closely linked with human life. It has high nutritional value and health function in human body, and has already been wildly used in foodstuff, drug and cosmetic.Banana peel was used as raw material. Macroporous resins adsorption method is used for adsorbing and separating polyphenols form the extraction solution, and then studied on their absorbing and separating properties. The extraction separation processconditions has been optimized. The UPLC method was used for determinating species and contents of polyphenol from the extraction solution which had been extracted from banana peel polyphenol. Mainly researched on the antioxidatives of banana peel polyphenol.The mainly researches as follows:1.Total content of polyphenol is quantitatively detemined by means of FC regent which gorms a highly stability. Gallic acid was used as the standard substance, linear range was 0.1～20μg/mL, detection limit was 0.2μg/mL, and there is high precision;good reproducibility.The standard curve equation is Y= 0.113x+0.0093, and R2=0.9991.2.The ultrasonic extraction was used.The best extraction condition which is got through single factor experiment and orthogonal experiment are:ethanol concentration is 70%, solid vs liquid ratio is 1:6, temperature is 60℃, extraction time is 40min, the extraction rate is 1.46%.3. XAD-7 resin was the best purification one,it could absorb polyphenols from extraction solution within 2 hours. The extraction solution could be adsorpted within changing pH. XAD-7 resin has a high adsorption rate with banana peel polyphenols when the sample's concentration is 0.1mg/mL and the sample's flow rate is 0.6mL/min. The ethanol was used as eluting regent with contralized peak, good symmetry and no siginificantly tailing.4.The adsorbing process was an exothermic course, it belonged to physical absorption. The whole process accorded with Langmuir isothermal model.5.The result of UPLC showed that the XAD-7 resin could effectively absorb polyphenols from banana peel extraction, and most banana peel polyphenols could be absorded on the resin column.11 polyphenols could be identified, the contents were as follow:Catechin:0.435mg/g; Epicatechin:1.027mg/g; Rutin:0.674mg/g; Chlorogenic acid:1.245mg/g; Caffeic acid:0.320 mg/g; Syringic acid0.238mg/g; P-coumaric acid:0.149 mg/g; Ferulic acid:0.260mg/g; Dihydroxy benzoic acid:0.341mg/g; Trans-cinnamic acid:0.014mg/g; Phloridzin:0.014mg/g.6.In antioxidative experiment indicated that banana peel polyphenols had stronger antioxidative activity than VC and tertiary butylhydroquinone. Banana peel polyphenols revealed powerful inhibitory effects on peroxidation of polyunsaturated fatty acid from yelk lipoprotein induced by Fe2+at all the tested concentrations, it was higher than VC but lower than tertiary butylhydroquinone.