Research On Extraction Purification And Activity Of Polyphenol From Aronia Melanocarpa

Aronia melanocarpa is the fruit of perennial deciduous shrub,which belongs to the berries.Aronia melanocarpa contains proanthocyanidins,anthocyanins,quercetin and other polyphenols,organic acids,three terpenes,dietary fiber and other bioactive components.In particular,the total content of polyphenolic compounds reaches 2.5%-3.5%,which is higher than that of blueberry,cowberry and cranberry.Several beneficial physiological functions such as antioxidant activity,anti-inflammatory,anti-carcinogenic,hypoglycemic and hepatoprotective of Aronia melanocarpa have been reported.With the growth of Aronia melanocarpa industry at present,some food like juices,wine and jam,as well as health care products are more popular in the market.However,many by-products like pomace have not been used effectively in Aronia melanocarpa product processing,resulting in a waste of resources.The present work was focused on the research of extraction,purification and activity of polyphenols from recycled Aronia melanocarpa pomace.These results have a very important significance to improve the comprehensive utilization rate of Aronia melanocarpa resources and additional value of products.1.For the enhancement of total polyphenols yield and total flavonoids yield in Aronia melanocarpa pomace,on the basis of single factor experiment,response surface methodology was introduced to optimize the extraction process of total polyphenols and flavonoids by ultrasound-assisted aqueous two-phase extraction.The experimental results showed that optimal extraction conditions of total polyphenols were as follows:ammonium sulfate concentration of 0.324 g/mL,ethanol-water ratio of 0.69,ultrasonic time of 52 min and ultrasonic power of 200 W.Meanwhile,ammonium sulfate concentration of 0.320 g/mL,ethanol-water ratio of 0.71,ultrasonic time of 50 min and ultrasonic power of 200 W were determined as optimum extraction conditions of total flavonoids.Experimental validation was performed,where polyphenols yield and flavonoids yield reached?68.15±1.04?mg/g and?11.67±0.63?mg/g,respectively.The relative error between experimental and predicted values is 0.13%and 2.91%,respectively.Overall,ultrasound-assisted aqueous two-phase system extraction method is successfully employed to extract polyphenol compounds in Aronia melanocarpa.2.In order to make Aronia melanocarpa polyphenols obtained fine utilization,macroporous adsorption resin method was applied to the separation and purification process of Aronia melanocarpa polyphenols extracts.By comparing the purification effect of HPD-600,NKA-9,AB-8 and D101 resins on Aronia melanocarpa polyphenols,HPD-600 resin was selected as the best resin.The purification process parameters of Aronia melanocarpa polyphenols with HPD-600 resin were as follows:sample concentration of 4.64 mg/mL,original pH value,sample flow velocity of 1.0 mL/min,sample volume of 6.0 BV,ethanol concentration of 60%,elution velocity of 0.5 mL/min and elution volume of 2.5 BV.Under this condition,the purity of Aronia melanocarpa polyphenols increased from 15.54%to 76.90%,and improved 4.95 times.3.Through the research of static adsorption kinetics of HPD-600 resin,the results indicated that the adsorption processing fitted the pseudo-second-order kinetics model.Through a nonlinear curve fitting with the Langmuir and Freundlich adsorption models,it was found that the isothermal adsorption process of HPD-600 resin on Aronia melanocarpa polyphenol was monalayer preferential adsorption.4.The identification of the components of Aronia melanocarpa polyphenols was studied by FT-IR and HPLC-MS,four substances of Aronia melanocarpa polyphenols were speculated,including Caffeic acid,Quinic acid,Kaempferol-3-O-Glucoside and Kaempfero 1-Arabino side.5.The inhibition effects of Aronia melanocarpa polyphenols on different bacteria and molds were investigated by filtering paper method.The results demonstrated that Aronia melanocarpa polyphenols certainly inhibited the activities of Escherichia Coli,Staphylococcus aureus,Aspergillus flavus,Aspergillus fumigatus,Rhizopus oryzae,Penicillium islandicum and Trichoderma koningii.Among them,the inhibitory effect on Staphylococcus aureus was stronger than that of Escherichia Coli.And the strongest inhibition effect against Aspergillus fumigatus and the minimal inhibition content?MIC?of Aronia melanocarpa polyphenols was 0.1719 mg/mL.By studying the influence of temperature and pH value on antibacterial effect,the results showed that for Staphylococcus aureus,the heat treatment?70??had a slight promoting role on the antimicrobial effect of Aronia melanocarpa polyphenols.Under the condition of pH 5.0,Aronia melanocarpa polyphenols had the strongest antibacterial activities on Staphylococcus aureus.But for Aspergillus fumigatus,the change of treatment temperature and pH value had a destructive effect on antibacterial effect.6.The inhibition effect and mechanism of Aronia melanocarpa polyphenols on a-amylase were studied.The results showed that Aronia melanocarpa polyphenols have obvious inhibitory effect on a-amylase.Compared with the positive control of acarbose,the inhibitory activity of Aronia melanocarpa polyphenols on a-amylase is stronger than that of acarbose within the range of 0.10-0.70 mg/mL.Aronia melanocarpa polyphenols showed non-competitive reversible inhibition effects on a-Amylase with the constant of inhibition of 0.1932 mg/mL.At the wavelength of 202 nm,Aronia melanocarpa polyphenols led to the enhancement of a-Amylase ultraviolet absorption and the redshift of absorption peak.7.The effects of temperature,medium pH value,light and metallic ions on the stability of Aronia melanocarpa polyphenols were explored.The experimental result indicated that Aronia melanocarpa polyphenols were found to be stable under low temperature,light-avoiding and weakly acidic conditions.Aronia melanocarpa polyphenols could be damaged by Zn²⁺,Mg²⁺,Al³⁺,Ca²⁺,Cu²⁺ and K⁺,especially for Cu²⁺.The thermal degradation of Aronia melanocarpa polyphenols conformed to a first-order kinetic model,and the rate constants of thermal degradation reaction at 30?,50?,70? and 90? were 0.0189?0.0192?0.0290 and 0.0553,respectively.Its apparent activation energy was 16.27 kJ/mol.