Mother liquor sugar (MLS) is a by-product of industrial production of steviol glycosides and composed of rebaudioside A (RA), stevioside (St), rebaudioside C (RC), some flavonoids and polyphenolic compounds. This study developed an efficient method to recovery RA from MLS based on the effect of some inorganic salts to the solubilities of components in MLS. RA could be concentrated by K₂CO₃ salting-out from 20% (wt%) to more than 60% (wt%) with 56.8% of recovery yield, and the mass ratio of RA to St (RA/St) was increased from to 0.47 to 4.18 in 10 min. The mechanism of the selective salting-out was primarily explored. Comparing with present methods such as two-stage crystallization method and macroporous resin adsorption, this method exhibited remarkable advantages of high recovery, shorter recovery time, simple operation and free of organic solvent. It could provide an alternative treatment for MLS and similar mother liquors.

母液糖（MLS）是甜菊糖苷工业生产的副产品，由莱鲍迪甙A（RA），甜菊糖甙（St），莱鲍迪甙C（RC），一些类黄酮和多酚化合物组成。这项研究基于一些无机盐对MLS中各组分溶解度的影响，开发了一种从MLS中回收RA的有效方法。RA可以被K ₂ CO ₃浓缩盐析从20％（wt％）增加到60％（wt％）以上，回收率为56.8％，RA与St的质量比（RA / St）在10分钟内从0.47增至4.18。初步探讨了选择性盐析的机理。与目前的两步结晶法和大孔树脂吸附法相比，该方法具有回收率高，回收时间短，操作简单，无有机溶剂的显着优点。它可以为MLS和类似的母液提供替代处理。