α-Amylase: Its Structure, Molecular Modification, and Application in the Food Field

This review comprehensively examines the structural architecture, catalytic mechanisms, and targeted molecular engineering of α-amylase (primarily the GH13 family), a pivotal biocatalyst in the food industry. We highlight diverse microbial sources of α-amylases and their cost-effective heterologous expression in well-characterized hosts like Bacillus subtilis and Escherichia coli. To overcome extreme operational bottlenecks—such as elevated temperatures and acidic environments—recent advances in protein engineering are critically evaluated. These strategies, including directed evolution, semi-rational design, and advanced immobilization on nanomaterials, synergistically enhance the enzyme’s thermostability, catalytic efficiency, and reusability. Furthermore, this paper synthesizes the state-of-the-art applications of engineered α-amylases across key food processing sectors, including baking, sugar refining, and brewing. By integrating structural biology with advanced material science, this review provides a targeted roadmap for developing next-generation, high-performance α-amylases to address current and future challenges in sustainable food processing.