Enzymatic acidolysis of tristearin with lauric and oleic acids to produce coating lipids

Triacylglycerols with potential for coating application were prepared by acidolysis of tristearin with lauric and oleic acids using Lipozyme 1M60 lipase in n-hexane. The effects of reaction parameters such as time, temperature, substrate mole ratio, water content, enzyme load, and enzyme reuse were studied. Five-gram scale synthesis was carried out to obtain the melting profile of products by differential scanning calorimetry (DSC). An acceptable melting profile was obtained for the product obtained with a 1:4:1 (tristearin/lauric acid/oleic acid) mole ratio of reactants. The DSC melting peak for this product was 31.4 degreesC. Synthesis of 1200 g of this product was carried out at a 1:4:1 substrate ratio in a stirred tank batch reactor under optimal conditions. The reaction product, purified by short-path distillation, was coated onto crackers and studied for its moisture inhibition ability, under water vapor-saturated atmosphere, in a desiccator over different time intervals. The effectiveness of the synthesized lipid as a coating material was compared against uncoated crackers as a control and with cocoa butter-coated crackers. The synthesized lipid was better in preventing moisture absorption than cocoa butter.