Evaluation of n-alkylated chitosan microspheres as support for immobilization of Rhizomucor Miehei lipases

PALLA, CAMILA; LOZANO, JORGE E.; CARRIN, MARIA ELENA

Antalya

Congreso; 1st International Congress on Food Technology; 2010

Lipases have been widely accepted as biocatalysts for the modification of oils and fats being of current interest to scientists and industrials, particularly to obtain trans-free fats and oils. An additional advantage is obtained when immobilized enzymes are used. In this work, biological catalysts, suitable for producing structured lipids from sunflower oil and saturated fatty acids (palmitic-stearic), were prepared. To that purpose, chitosan microspheres were performed by precipitation and hydrophobically modified in different degree by reductive amination. Different aspects of that last procedure were analyzed in order to obtain the most appropriate support for lipase immobilization: amination time, aldehyde concentration and their interaction. Lipases from Rhizomucor miehei were physically adsorbed on the prepared supports, and the catalytic activity of these enzyme derivatives was evaluated using acidolysis reaction in a solvent system. The effect of the protein content in the biocatalysts and the stability of their reuse was also investigated. The most active biocatalysts, with medium modification degree, achieved a change in the composition of palmitic and stearic acid from a value of 9.56% in the original oil to 54.25% in the final structured lipid. This high conversion was maintained during 3 practiced reuses. This demonstrated that chitosan modification was effective.