Research On The Polyphenols Extraction And Purification Of Pine Nut Coat And Its Antioxidant Characteristics

In this research, pine nut coat as main raw material, extraction and purification process of polyphenols in pine nut coat were studied, and use of high performance liquid chromatography preliminarily identified the components of polyphenols in pine nut coat. By antioxidant tests in vitro measured the antioxidant activity of polyphenols in pine nut coat and applyed the pine nut coat polyphenols to develop a pine nut coat polyphenols oral.Extracting yield of polyphenols were chosen as indicators, ethanol solvent extraction, microwave-assisted extraction and ultrasonic-assisted extraction process conditions were studied respectively to determine the optimum extraction of polyphenols in pine nut coat. Results showed that the optimum conditions of ethanol solvent extraction of polyphenols was ethanol concentration62%, solid-liquid ratio1:25(g/mL), extraction time150min, temperature65℃, extracting yield was14.642mg/g. Optimum conditions of microwave-assisted extraction of polyphenols was ethanol concentration62%, solid-liquid ratio1:25(g/mL), microwave power350W, microwave time3.5min, and then placed it at65℃for90min in water bath, extracting yield was17.128mg/g. Optimum conditions of ultrasonic-assisted extraction of polyphenols was ethanol concentration62%, solid-liquid ratio1:25(g/mL), ultrasonic power300W, temperature70℃for90min, extracting yield was23.562mg/g. According to a comprehensive analysis of extracting yield, time and cost, ect, ultrasonic-assisted extraction process was chosen as optimum extraction process.Extraction liquid of polyphenols in pine nut coat was chosen as raw material, AB-8macroporous resin was chosen as separation medium, adsorption rate and desorption rate as indicators, static and dynamic adsorption-desorption tests were studied. Besides, use of high performance liquid chromatography preliminarily identified the components of polyphenols in pine nut coat. Results showed that optimum process was as follows:concentration of polyphenols was2.0mg/mL, the sample flow rate was1.0mL/min, the eluent was80%ethanol, the flow rate was0.5mL/min. Polyphenol purity71.21%. After a preliminary identification of high-performance liquid chromatography, composition of polyphenols in pine nut coat included3,4dihydroxybenzaldehyde, vanilla acid, p-coumaric acid, ferulic acid, cinnamic acid esters and catechins.In this paper, by antioxidant activity experiment to study the antioxidant activity of polyphenols in pine nut coat, and developed the best formulation of polyphenols oral. The results showed that polyphenols of the pine nut coat had antioxidant activity, which scavenged hydroxyl radical EC50values was0.458mg/mL, scavenged DPPH free radicals EC50values was0.0142mg/mL and scavenged hydrogen peroxide EC50values was1.186mg/mL. Polyphenols oral capacity lOmL/bottle, polyphenols (purity70%) added0.6%the best formulation of polyphenols oral was as follows:the amount of sugar was6.0%, honey was6.5%, citric acid was0.07%, vitamin C was0.05%.