Kinetics and thermodynamics of rebaudioside A adsorption on a strongly acidic cation exchange resin

Abstract

To explain the mechanism underlying the adsorption of stevia's polar component rebaudioside A in hydrophilic interaction liquid chromatography mode, the characteristics of rebaudioside A adsorption on various resins in an organic‐solvent‐rich system were studied. Among the tested resins, the strongly acidic cation resin FPC11 showed the best adsorption behavior for rebaudioside A. The factors affecting the adsorption kinetics of the resin for rebaudioside A are discussed. The results showed that the pseudo‐second‐order reaction model and intra‐particle diffusion model best described the adsorption kinetics of rebaudioside A on the resin. The adsorption rate was controlled by physical sorption, mainly via electron sharing or electron transfer between the adsorbent and the adsorbate. The adsorption process with multiple stages involved weak initial adsorption behavior. Thermodynamic studies showed that the adsorption of rebaudioside A on the resin was not an ideal monolayer adsorption, but mutual adsorption effects between the adsorbates. The adsorption was a spontaneous, entropy‐increasing endothermic process. The synergistic effect of hydrogen bonding and ion–dipole was a possible driving force.

A well‐defined hierarchically porous metal–organic framework and its application in separation and purification of steviol glycosides

“…Steviol glycosides (SGs) are tetracyclic diterpenoids extracted from stevia rebaudiana, which is 250-450 times sweeter than sucrose, and can be used as natural sweetener to replace sucrose [1][2]. In addition, SGs have a variety of pharmacological and biological functions [3].…”