GH77家族4-α-糖基转移酶在淀粉改性中应用的研究进展

糖苷水解酶（glycoside hydrolase，GH）77家族4-α-糖基转移酶（4-α-glucotransferase，4αGT）由于对α1→4糖苷键的独特作用而被广泛应用于淀粉改性中。4αGT通过分子间转糖基化将淀粉凝胶改性为热可逆淀粉凝胶，还进行分子内转糖基化生产大环糊精，而且经4αGT处理淀粉的慢消化特性有所改善。4αGT可与分支酶和淀粉蔗糖酶等协同制备更具抗性的α-葡聚糖产品。4αGT改性淀粉在低脂食品、甜味剂和冷冻食品中有着广泛的应用前景，其作为脂肪替代物和乳脂状增强剂添加到蛋黄酱、低脂涂抹酱、搅拌型和凝固型酸奶中，有潜力代替碳水化合物冷冻保护剂成为低甜度冷冻保护剂。全文综述了GH77家族4αGT改性淀粉在应用方面的进展与挑战，为4αGT的工业生产提供参考。

Progress in the Application of 4-α-Glucotransferase,a Member of the Glycoside Hydrolase 77 (GH77) Family,in Starch Modification

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.