Production of PUFA Concentrates from Sardine Oil by Enzymatic Hydrolysis in Organic Media 
Morales-Medina, R.; Muñio M.; Camacho, F.; Guadix A.M. and Guadix E.M.
Department of Chemical Engineering. Faculty of Sciences, Avda. Fuentenueva s/n, University of Granada, Spain
Tel: +34958240532; Fax: +34958241329; E-mail: eguadix@ugr.es

The efficiency of the human digestibility and metabolism of lipids is sensitive to the position of the fatty acids (FA) within the glycerol backbone; being those FA located in the sn2 position more easily absorbed. Regiodistribution of FA of sardine oil was studied resulting that 81.98 mol% of DHA was located in sn2 position. Hence, the employment of selective hydrolysis in non-conventional media was chosen for the concentration of oils maintaining the central position. 

Three regiospecific 1,3-lipases enzymes were selected: immobilized Rhizomucor miehei (RM) Rhizopus oryzae (RO) and Thermomyces lanuginosus (TL) aiming at studying the kinetic process. The hydrolysis were conducted with a 10wt% of enzyme, 2.5g of oil, 125 µL of water (which represented a 10% of excess respect to the stoichiometric mass) and 25mL of hexane. After 24 hours of reaction the amount of remaining triacylglycerides (TAGs) was 15.36mol% and water activity had decreased to 0.5%. The amount of EPA and DHA in diacylglycerides (DAGs) achieved a maximum of 33.28mol%, which involved an increase of 20mol% with respect to the original oil. Further steps are focus on studying the influence of the activity water in the kinetics process.