Process intensification of acidolysis reaction catalysed by enzymes for synthesis of designer lipids using sonication

Designer lipids find a wide range of applications in food, pharmaceuticals and nutraceutical industries. The current work focuses on intensified production of designer lipids using ultrasound assisted enzymatic acidolysis reaction between long chain triglycerides from Linseed oil (LO) and MCFAs i.e. octanoic acid or decanoic acid. The synthesised designer lipids contain sn-1,3 position on glycerol backbone occupied by MCFAs and sn-2 position occupied by PUFAs, thus having the potential of numerous applications in food and pharma sector. Studies into effect of ultrasound parameters and reaction conditions on the yield demonstrated that the optimum operating conditions as molar ratio of LO: MCFAs of 1:5, temperature of 40 °C and Novozyme 435 dosage of 5% (based on substrate weight) as well as ultrasound conditions of 50% duty cycle and 90 min of irradiation time resulted in maximum yield as 96%. Comparison of ultrasound assisted synthesis with the conventional synthesis (less than 20% yield in 90 min and requirement of 26 h to reach equilibrium yield of 82.6%) demonstrated the intensification benefits as higher yield and lower reaction time for the ultrasound assisted approach. It was also elucidated that Novozyme 435 was effectively recycled for 12 cycles without much effect on the yield. Overall the work clearly demonstrated the efficacy of the ultrasound intensified approach for synthesis of designer lipids, also elucidating key design information for the optimum operating conditions.