Hydrolysis of vegetable oils catalyzed by lipase extract powder from dormant castor bean seeds

The aim of this work was to verify the ability of lipase extract powder from dormant castor bean seeds (Ricinus communis L) to the hydrolysis of different vegetable oils for yielding concentrated fatty acids. The enzymatic extract showed higher activity on oils rich on linoleic (C-18:2) and linolenic acids (C-18:3) such as soybean (86.1 +/- 2.3IUg(-1)) and canola (81.3 +/- 2.4IUg(-1)) than on oil rich on oleic acid-olive oil (61.1 +/- 4.5IUg(-1)). The enzymatic hydrolysis performed in stirred-tank reactor displayed hydrolysis degree higher than 80%, with a maximum value attained for canola oil (88.2 +/- 6.80%) after 3 h of reaction. An experimental design was performed to better understand the influence of the independent variables (mass ratio canola oil:buffer, temperature and CaCl2 concentration) and their interactions in the hydrolysis degree. The main effects were fitted by multiple regression analysis to a quadratic model and full hydrolysis of canola oil was achieved at 37.5 degrees C without CaCl2 addition and mass ratio oil:buffer (22.1 wt.%). At higher mass ratio oil:buffer (up to 30 wt.%) full hydrolysis could also be attained after 2 h at 37.5 degrees C. These results suggest that the use of low-cost lipase from dormant castor bean seeds has potential for the production of concentrated fatty acids. (C) 2012 Elsevier B.V. All rights reserved.