Adsorption of Maillard reaction products from aqueous solutions and sugar syrups using adsorbent resin

Adsorption of the Maillard reaction products (MRP) onto a styrene–divinylbenzene copolymer based adsorbent resin (AR) was studied. The effects of various parameters such as temperature, AR concentration, contact time, and sugar concentration were investigated. Among various isotherms, the equilibrium data fitted best to the GAB isotherm which indicated a multilayer adsorption of MRP onto AR. The temperature strongly influenced the adsorption process. The thermodynamic parameters Ea, ΔH, ΔG and ΔS indicated that the adsorption process was exothermic and spontaneous process which is favored at lower temperatures, and also occurred by both physical adsorption and weak chemical interactions. Adsorption of MRP onto AR obeyed the pseudo-second-order kinetic model and occurred by both surface sorption and intraparticle diffusion. The pore diffusion controlled the adsorption process at low sugar concentrations while the film diffusion governed the adsorption mechanism at high sugar concentrations. It was concluded that the adsorption process should be performed at sugar concentrations lower than 50% to overcome the film resistance.