Preparative separation and purification of Rebaudioside A from Stevia rebaudiana Bertoni crude extracts by mixed bed of macroporous adsorption resins

► We studied the preparative separation process of RA with nineteen MARs. ► Optimum mass ratio of resin HPD750, LSA40, LSA30 and DS401 was 3.75:2.5:0.05:0.45. ► Kinetic studies showed the adsorption kinetic curve accorded with pseudo-second-order model. ► The adsorption isotherm was consistent with IV equilibrium adsorption isotherm. ► Separation degree of the product increased 1.97-fold and the purity increased 1.62-fold.