title: Adsorption characteristics of adsorbent resins and antioxidant capacity for enrichment of phenolics from two-phase olive waste.
abstract: In this study, the adsorption properties of nine resins including polyamide resin (30-60), polyamide resin (60-100) AB-8, S-8, D-101, NKA-9, NKA-II, XDA-1 and XDA-4 for enrichment phenolics of the olive waste were investigated. XDA-1 and NKA-II were chosen for further study due to their outstanding adsorption and desorption capacity. XDA-1 and NKA-II had similar adsorption and desorption behaviors for phenolics of olive waste. The adsorption mechanism could be better explained by pseudo second-order kinetics model and Freundlich isotherm model, and the adsorption processes were spontaneously and exothermic. The experiment of gradient elution were carried out through treated XDA-1 resins column, the result indicated the total phenolics were mainly obtained from the 40% and 60% ethanol fraction. The order of antioxidant capacity by DPPH  , ABTS+radical and FRAP assay was similar with the content of phenolics from fraction elution. The compositions of phenolics from different elution fractions were determined by reversed phase-HPLC-DAD method. Gallic acid, hydroxytyrosol, tyrosol and ferulic acid were the major constituent in the fraction elute, and the content of hydroxytyrosol reached to the 41.69mg/g. The above results revealed the synergistic effects of the different phenolics contribute to the antioxidant capacity.
authors.affiliation: Institute of Chemical Industry of Forest Products, CAF, Nanjing 210042, China; Key and Open Laboratory on the Forest Chemical Engineering, SFA, Nanjing 210042, China; Key Laboratory of the Biomass Energy and Material, Nanjing 210042, China.
authors.forename: Zhihong
authors.initials: Z
authors.lastname: Wang
authors.affiliation: Institute of Chemical Industry of Forest Products, CAF, Nanjing 210042, China; Key and Open Laboratory on the Forest Chemical Engineering, SFA, Nanjing 210042, China; Key Laboratory of the Biomass Energy and Material, Nanjing 210042, China; Institute of New Technology of Forestry, CAF, Beijing 100091, China. Electronic address: wangczlhs@sina.com.
authors.forename: Chengzhang
authors.initials: C
authors.lastname: Wang
authors.affiliation: Institute of Chemical Industry of Forest Products, CAF, Nanjing 210042, China; Key and Open Laboratory on the Forest Chemical Engineering, SFA, Nanjing 210042, China; Key Laboratory of the Biomass Energy and Material, Nanjing 210042, China.
authors.forename: Jiaojiao
authors.initials: J
authors.lastname: Yuan
authors.affiliation: Institute of Chemical Industry of Forest Products, CAF, Nanjing 210042, China; Key and Open Laboratory on the Forest Chemical Engineering, SFA, Nanjing 210042, China; Key Laboratory of the Biomass Energy and Material, Nanjing 210042, China.
authors.forename: Changwei
authors.initials: C
authors.lastname: Zhang
mesh_terms: D000327:Adsorption; D000975:Antioxidants / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology*; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D005609:Free Radicals / Q000737:chemistry; D009757:Nylons / Q000737:chemistry; D031658:Olea / Q000737:chemistry*; D010084:Oxidation-Reduction; D010636:Phenols / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology*; D010936:Plant Extracts / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D012117:Resins, Synthetic / Q000737:chemistry; D013816:Thermodynamics; D014866:Waste Products / Q000032:analysis
chemical_list: D000975:Antioxidants; D005609:Free Radicals; D009757:Nylons; D010636:Phenols; D010936:Plant Extracts; D012117:Resins, Synthetic; D014866:Waste Products
keywords: Adsorption; Antioxidants; Olive waste; Phenolic compounds; Resins