Sintese de sucedâneos de gordura de leite humano enriquecidos em ácidos gordos polinsaturados ómega-3 do óleo de camelina, catalisada pela lipase heteróloga de Rhizopus oryzae

Mestrado em Engenharia Alimentar - Instituto Superior de AgronomiaIn 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 rich in omega-3 polyunsaturated FA, by enzyme-catalyzed acidolysis of tripalmitin with FA of camelina oil, in batch reactor and solvent-free media. An immobilized commercial lipase (“Lipozyme RM IMTM”) and a non-commercial heterologous Rhizopus oryzae lipase (rROL) were tested, as thermostable and sn-1,3 selective lipases. After 24h reaction at 60ºC, molar incorporations of 50.3% for "Lipozyme RM IMTM", 43.3% for rROL in Lewatit VPOC1600 and 19.5% for rROL in ReliZyme OD403/S were obtained. rROL immobilized in Lewatit was selected as an alternative to commercial lipases. With this biocatalyst (5% m/m), 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. Tripalmitin consumption increased from 62% (5% biocatalyst load) to 88% with 8 or 10% loads, as well as the formation of new triacylglycerols