Title: The use of grapeseed oil for the production of structured lipids catalyzed by a recombinant Rhizopus oryzae lipase
Author: Suzana Dias
Last saved by: Saritas, Sevim

Production of Human Milk Fat Substitutes Rich in Polyunsaturated Fatty Acids from Camelina Oil, Catalyzed by a Recombinant Rhizopus oryzae Lipase
Ana Rita Faustino^(1), Carla Tecelão^(1,2), Natália M. Osório^(1), Albert Canet^(3),Francisco Valero^(3), Suzana Ferreira-Dias^(1)* 
^(1)Universidade de  Lisboa, Instituto Superior de Agronomia, CEER, Tapada da Ajuda, Lisbon, Portugal; ^(2) School of Tourism and Maritime Technology, Marine Resources Research Group, Polytechnic Institute of Leiria, Peniche, Portugal;^(3)Departament d’Enginyeria Quimica (EE), Universitat Autònoma de Barcelona, 08193 Bellaterra, Barcelona, Spain

In human milk fat (HMF), palmitic acid is mostly esterified at the internal position of triacylglycerols, while unsaturated fatty acids (FA) are at the external positions, creating a single structure in Nature. 
This study aims at the production of HMF substitutes (HMFS) rich in omega-3 polyunsaturated FA, by enzyme-catalyzed acidolysis of tripalmitin with FA of camelina oil, in batch reactor and solvent-free media. The camelina (Camelina sativa L.) oil used presented 56.5 % of polyunsaturated fatty acids, being linolenic acid the major compound (35.5 %). The heterologous sn-1,3 selective Rhizopus oryzae lipase (rROL) immobilized in Lewatit VPOC1600 or in ReliZyme OD403/S was tested as alternative to the high cost thermostable and sn-1,3 selective immobilized commercial Rhizomucor miehei lipase, “Lipozyme RM IM^TM” from Novozymes. After 24h reaction at 60ºC, molar incorporations of 50.3% FA for "Lipozyme RM IM^TM", 43.3% for rROL immobilized in Lewatit VPOC1600 and 19.5% for rROL immobilized in ReliZyme OD403/S were obtained. Therefore, rROL immobilized in Lewatit was selected as an alternative to commercial lipases. With this biocatalyst (5% w/w), the molar incorporation increased with the water activity and quasi-equilibrium was attained after 24 hours reaction.
Response surface methodology was used to model the acidolysis reaction catalysed by rROL, as a function of temperature (58ºC-72ºC) and molar ratio tripalmitin:FFA (1:1.2-1:6.8). Tripalmitin consumption decreased with the increase of both factors. 
Using higher loads of biocatalyst (8% and 10%), tripalmitin consumption increased but a decrease in the formation of new triacylglycerols was observed.