Adsorption and desorption characteristics of adlay bran free phenolics on macroporous resins. (1st March 2016)

• Record Type: Journal Article
• Authors: Yang, Qingyun; Zhao, Mouming; Lin, Lianzhu
• Is Part Of: Food chemistry. Volume 194(2016)
• Page Start: 900
• Page End: 907
• Publication Date: 2016-03-01
• Subjects: Macroporous resins -- Adlay bran -- Free phenolics -- Antioxidants -- Adsorption behaviors; Food -- Analysis -- Periodicals; Food -- Composition -- Periodicals; 664
• DOI: 10.1016/j.foodchem.2015.08.070
• Languages: English
• ISSNs: 0308-8146

Abstract

Highlights: XAD-16, SP-207 and SP-825 resins had similar adlay phenolics adsorption behaviors. Boundary layer and intra-particle diffusion kinetics affected adsorption processes. Adsorption equilibriums were well-fitted to the Freundlich isotherms. Adsorption processes were exothermic and physical. Antioxidant-related components were effectively enriched by gradient elution. Abstract: In this study, the adsorption and desorption characteristics of six macroporous resins including XAD-7HP, XAD-16, HP-20, HP-2MGL, SP-207 and SP-825 for enrichment of adlay bran free phenolics were studied. XAD-16, SP-207 and SP-825 were chosen for further study due to their strong adsorption and desorption capacities. XAD-16, SP-207 and SP-825 had similar phenolics adsorption/desorption behaviors. Pseudo -second-order kinetics model and Freundlich isotherm model were suitable for describing the whole exothermic and physical adsorption processes of adlay bran free phenolics on XAD-16, SP-207 and SP-825. After treatment with gradient elution on XAD-16 resin column, the free phenolics were mostly enriched (from 89.61 to 1015.26 mg/100 g) in 50% ethanol fraction. The oxygen radical absorbance capacity of 50% ethanol fraction was eight times higher than that of the crude extract. Therefore, the production of highly concentrated phenolics might expand the application of adlay bran used as a bioactive ingredient in functional food.