Study on adsorption effect of rebaudioside A and stevioside onto D392 macroporous resin

Based on the difference of molecular structure between rebaudioside A and other steviol glycosides, the performance and separation characteristics of fourteen selected commercial adsorbent resins for the separation and purification of RA had been evaluated. According to the results, D392 offered higher adsorption selectivity than other resins. Influential factors such as adsorption kinetics, adsorption isotherm, temperature, concentration and pH value of adsorption solution, and solvents to the adsorption selectivity were successively investigated on D392. The results showed that the ability of adsorption of S with D392 was stronger than that of RA. The adsorption process was exothermic in aqueous solution, and higher adsorption selectivity was found at lower temperatures. The RA/S ratio of the raffinate attained the maximum when the adsorption was conducted at 298. 15K, pH 7. 0, and 5g/L of the feeding solution (RA/S=1∶ 1) . After the treatment on D392, the content of RA in the product increased from 70. 3% to 88. 4%, and the recovery yield of RA was 68. 0%.