Review on Lipase-Catalyzed Flavor Synthesis: Global Trends and Advances.

The enzymatic synthesis of esterified flavors is pivotal in the food, pharmaceutical, and cosmetic industries. Among the available approaches, lipase-catalyzed reactions have gained increasing attention due to the enzymes' biodegradability, high enantio- and regioselectivity, availability, and effectiveness under mild, eco-friendly conditions, aligning well with the principles of green chemistry. This topic was selected due to the vast potential of biocatalysis in the sustainable and efficient synthesis of diverse flavor compounds. Using the Web of Science database with the keywords "flavor", "enzyme", and "lipase", 189 relevant articles were identified, revealing that the majority of publications fall within the fields of chemistry, food science, and biochemistry. This review explores the catalytic mechanisms of lipases during acetylation reactions, focusing on structural conformational changes during enzymatic processes. Lipases from Candida antarctica (notably CALB, Lipozyme, and Novozym 435) emerge as the most commonly employed biocatalysts for esterified flavor production. Interestingly, most studies emphasize the immobilization supports rather than the intrinsic properties or engineering of the enzymes themselves. The findings underscore a growing global interest in enzyme-mediated flavor synthesis. Future studies should explore enzyme engineering to enhance activity and specificity, broaden the range of usable substrates, and improve the operational stability. Key challenges include the high cost of enzyme production, limited substrate scope in some systems, and the need for scalable, cost-effective bioprocesses for industrial applications.