Debashrita Majumder, T.N. Saha, Debasmita Bhattacharya, Shareen Singh, Mithul Rajeev, Moupriya Nag, Dibyajit Lahiri, Soumya Pandit
Diacylglycerols (DAGs) are metabolically and structurally different lipids of growing importance in food, pharmaceutical, and nutraceutical uses. Their stereospecific structure, especially the Sn-1,2 and Sn-1,3 isomers, regulates lipid absorption, β-oxidation, and postprandial metabolism, even though DAGs contain comparable caloric value to triacylglycerols (TAGs). Regioselective lipases, like Sn-1,3- and Sn-2-specific enzymes, enable specific synthesis of functional DAGs, but hurdles such as acyl migration and the paucity of comparative studies on enzymatic efficiency remain. This review integrates traditional production pathways (glycerolysis, hydrolysis, interesterification) with novel technologies such as immobilized lipases, deep eutectic solvents (DESs), and reverse micellar systems, which enhance regioselectivity, stability, and reaction control. Biocatalysis by reverse micelles, in particular, increases substrate solubilization and reduces unwanted side reactions, thus enhancing DAG synthesis under low-water conditions. Computational methods, such as molecular docking and dynamics simulations, are presented for the rational design of enzymes and substrates. Moreover, state-of-the-art analysis platforms like high-performance liquid chromatography tandem mass spectrometry (HPLC–MS/MS) and 13 C nuclear magnetic resonance (NMR) are accessed for accurate regioisomer identification. Extensive commercial Sn-specific lipase comparisons based on catalytic yield, specificity, heat stability, and industrial application are included. With the combination of a mechanistic understanding with scalable process approaches, this review provides a translational paradigm for high-purity DAG manufacturing for metabolic well-being and functional lipid applications.