Upgrading sesame cake-extracted oil via enzymatic glycerolysis: Production and characterization of diacylglycerol-enriched oil.

Solvent-extracted oil from pressed sesame cake has limited value due to flavor loss. This study developed an enzymatic strategy to convert it into diacylglycerol (DAG)-enriched oil via Novozym 435-catalyzed glycerolysis. Under optimized conditions (molar ratio 1:4, enzyme loading 10%, 90 °C), efficient DAG formation was achieved by overcoming multiphase mass transfer limitations. The product was dominated by 1,3-DAG, with a significantly higher proportion than 1,2-DAG. Fourier transform infrared confirmed structural reconfiguration of glycerides, while gas chromatography analysis showed that polyunsaturated fatty acids were well preserved, indicating mild processing. Notably, the peroxide value of DAG oil was significantly lower than that of the original triacylglycerol oil, while the p-anisidine value remained stable, demonstrating enhanced oxidative stability. The product also exhibited a brighter yellowish-green appearance due to polar component formation. Overall, this study provides an effective pathway for upgrading sesame by-products into functional lipid ingredients.