Abstract: The present invention discloses a method for preparing glucosyl steviol glycosides through enzymatic catalysis under programming temperatures in high throughput, belonging to the technical field of biosynthesis of sweeteners. By using cyclodextrin glucosyltransferase from Geobacillus sp. as a catalyst, steviol glycosides as the glycosyl receptor and dextrin or oligosaccharide as the glycosyl donor, taking a calcium/barium ion salt bridge as the main stabilizer and combining with glycerol to adjust the conformation and binding domain openness of the enzyme, and utilizing transglucosylation and hydrolytic activities of amylase at variable temperatures in different stages, thereby preparing the glucosyl steviol glycosides through enzymatic catalysis under programming temperatures in high throughput. The technology of the present invention can improve the utilization rate of the enzyme, and obtain glucosyl steviol glycosides with good sweetness and good taste.

Abstract: The present invention discloses a method for preparing lower graft degree GSGs, and belongs to the technical field of biosynthesis of sweeteners. The method uses amylase to catalyze hydrolysis of GSGs with a high graft degree, thereby obtaining GSGs with low graft degree mainly containing GSGs with a low grafting number. The content of mono- and di-glucosyl substituents in the SGs in the product was 60% or more of the total glycosides, and the mass percent of the GSGs with a glucosyl grafting number of 3 or less was higher than 70% of the total glycosides. The mono- and di-substituted GSGs obtained by enzyme catalysis by the present invention were structurally similar to those, belong to a mixture of the isomers thereof, and have good sweetness and a flavoring function.