Recovery Of Rebaudioside A From Mother Liquor Sugar In Industrial Steviol Glycoside Production By Adding Inorganic Salts

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.