Abstract: 4-α-Glycosyltransferase (4αGT), belonging to the glycoside hydrolase 77 (GH77) family, is widely used in starch modification due to its unique action on α1→4 glycosidic bonds. 4αGT can modify starch gels to make them become thermoreversible by intermolecular transglycosylation, and it also can be used to produce large ring cyclodextrin by intramolecular transglycosylation. Moreover, the slow digestion characteristics of starch can be improved by treatment with 4αGT. 4αGT can be used in synergism with branching enzyme and/or amylosucrase to prepare α-glucan products with stronger resistance to digestion. 4αGT-modified starch holds promise for broad applications in low-fat foods, sweeteners and frozen foods, and has the potential to replace carbohydrate cryoprotectants as a low-sweetness cryoprotectant when added as a fat substitute and creamy enhancer to mayonnaise, low-fat spread, and stirred and set yogurt. This paper reviews the recent progress and some of the challenges in the application of 4αGT-modified starch, with the aim of providing a reference for the industrial production of 4αGT.

Key words: 4-α-glycosyltransferase; starch modification; thermoreversible starch gel; large ring cyclodextrin