Research progress in kojibiose: structural insights, enzymatic synthesis, and applications in food and pharmaceutical industries

Kojibiose, a rare disaccharide featuring a unique α-1,2-glycosidic linkage, exhibits functional properties such as significant sweetness, prebiotic activity, and iron absorption enhancement. It acts as an α-glucosidase I inhibitor, highlighting its potential in the food and pharmaceutical sectors. While natural extraction and chemical synthesis are limited by scalability and environmental concerns, enzymatic synthesis stands out as an alternative, offering high efficiency, specificity, and sustainability. Current enzymatic systems, including sucrose phosphorylase, kojibiose phosphorylase, and dextransucrase, combined with β-galactosidase or α-glucosidase, have shown considerable progress. Protein engineering of sucrose phosphorylase has further improved catalytic efficiency and thermostability. However, enzymatic synthesis still faces challenges, including low catalytic efficiency, instability, and high substrate costs, which impede large-scale production. Moreover, incomplete safety evaluations, unclear regulatory standards, and the absence of uniform quality specifications hinder compliant application. This review systematically outlines the structural features, physicochemical properties, and enzymatic synthesis strategies of kojibiose, with an emphasis on the role of protein engineering in scaling up production. It also evaluates its functional applications in health promotion, food quality improvement, and therapeutic uses. Finally, interdisciplinary innovations are proposed to establish technical standards and scalable bioprocesses, aiming to overcome current barriers and realize the commercial potential of sustainable kojibiose production.