Lipase-Based Fat Splitting of High Erucic Acid Rapeseed Oil for Industrial Applications

Industrial fat splitting, specifically of high erucic acid rapeseed oil is an economically valuable process, which CRODA employs to produce thousands of tons of erucic acid and other fatty acids and glycerol. This project explores enzymatic methods for HEAR oil splitting, and their potential industrial applications. Within this work, several different lipases are compared for their activity on HEAR oil under different conditions. Initial work was focussed on determining the activity of lipases on HEAR oil. Lipases used were from mammalian and fungal sources. Comparisons between these lipases focussed on their activity on HEAR oil measured in acid value as well as their regio-selectivity. Both, to determine the specificity of these enzymes on HEAR oil and to gain insights into the final, and intermediate products of the splitting reaction we used thin layer chromatography (TLC). TLC allowed us to determine intermediates of the HEAR oil splitting reaction, specifically, it allowed us to distinguish between different diacylglycerols, which let us classify lipases of unknown specificity into sn-1,3 specific and non-specific. Thermomyces lanuginosus lipase (TLL) variants as well as Candida rugosa lipase and Candida antartica lipase A were identified as ideal lipases for HEAR oil hydrolysis. Conditions for TLL based hydrolysis were optimised using a number of different factors including temperature, oil:water ratio, lipase amount, stirring speed, as well as buffer strength and initial pH. Combinations of lipases were also used to fully split HEAR oil within 24 hours. Partial HEAR oil hydrolysis for industrial use was also explored. Pre-splitting, in particular, was successfully shown to be potentially beneficial to an industrial pressure splitting process, allowing for a reduction in overall reaction time, or temperature and pressure while producing equal yields.