Processes for transglucosylation of steviol glycosides and steviol glycosides compositions prepared by the same

A process for producing α-1,4-glucosylated steviol glycosides, said process comprising:

• providing a steviol glycoside and a donor of glucosyl residues, wherein both are mixed in a predetermined ratio to obtain a reaction solution;
• adding CGTase for transglucosylation of steviol glycosides to the reaction solution;
• whereby the reaction solution is incubated at a predetermined temperature for a predetermined period;
• passing the reaction solution through a chromatographic column packed with sufficient amount of specific polar macroporous polymeric adsorbent;
• washing the column to remove impurities;
• and
• eluting adsorbed non-modified steviol glycosides and glycosylated steviol glycosides with an organic solvent solution;
• and
• removing the organic solvent, concentrating, and drying to produce a purified sweetener composition comprising α-1,4-glucosylated steviol glycosides.