Intensification of Enzymatic Synthesis of Corn Oil Designer Lipids Using Sonication

Designer lipid enriched in ω-6 polyunsaturated fatty acid (linoleic acid) at sn-2 position and medium-chain fatty acid (octanoic acid) at sn-1,3 position of glycerol skeleton was synthesised using enzymatic acidolysis of corn oil and octanoic acid catalysed by Novozyme-435. The importance of the work is demonstrated based on various nutraceutical applications of the corn oil designer lipids (CODL) in the food and pharmaceutical sector. The work demonstrates the intensification obtained due to ultrasound, also elucidating the effect of reaction and ultrasound parameters on the yield (%) of CODL. It was established that the maximum yield of 94% is obtained under best conditions of the molar ratio of corn oil: octanoic acid as 1:4, temperature as 40 °C and biocatalyst loading of 3% using ultrasound conditions of 70% duty cycle and irradiation time as 300 min. The conventional method of synthesis gave only 86% yield after 29 h of acidolysis reaction. CODL was stable to oxidative deterioration for 30 days at ambient temperature but corn oil showed rapid increase in peroxide value indicating oxidative damage. The ultrasound-induced cavitation has been demonstrated as greener, eco-friendly and energy-efficient process for the intensified synthesis of CODL with higher oxidative stability.