Optimization of the Production of Structured Lipid by Enzymatic Interesterification from Coconut (Cocos nucifera) and Sesame (Sesamum indicum) Oils using Response Surface Methodology

Abstract

Blends of coconut (Cocos nucifera) oil and sesame (Sesamum indicum) oil were enzymatically interesterified using aqueous lipase derived from Rhizomucor miehei and the reaction conditions, namely, temperature (45–65 °C), time (16–48 h) and mass ratio of oils (CO:SO; 70:30–50:50) were optimized using Response Surface Methodology (three-factor, three-level central composite design). Degree of interesterification (DI), and the ratio of monounsaturated and polyunsaturated fatty acids (MUFA:PUFA) of triacylglycerols were used as response variables. The linear effects of all factors were significant for the DI while for MUFA:PUFA, the linear effect of oil ratio and interaction effect of time and oil ratio showed significant effects. The conditions, temperature; 57 °C, time; 16 h and weight ratio of oil (coconut oil:sesame oil); 50:50 were found to be the optimum. The R2 value for DI and MUFA:PUFA ratio were 0.80 and 0.82, respectively. Models fitted for both DI and MUFA:PUFA ratio were significant with non-significant lack of fit. Produced structured lipid exhibited superior nutritional, physical and chemical properties than its raw counterparts. Therefore, the constructed models and data provide useful information to produce structured lipid from interesterification of coconut oil and sesame oil in up-scaled level. The produced novel lipid containing beneficial fatty acids from both oils could be used to produce healthy fat based products.