Characterization of the lipase from Carica papaya residues Caracterização da lipase de resíduos de Carica papaya

Lipases from vegetable sources have been the focus of intense and growing research. The use of enzymes from plants has the advantage of employing industrial waste products. Brazil is the world’s largest papaya producer and the market for products derived from papaya is growing year after year. In this study, the authors carried out the characterization and partial purification of the lipase obtained from the seeds and skin of Carica papaya. The most active fractions were those obtained using the technique of precipitation with 50% of acetone (EBFL-50 acetone), and the technique of fractioned precipitation with ammonium sulphate 40-80% (EBFL-40-80 sulphate). The EBFL-50 acetone fraction presented an optimum pH at 9.5, with a second peak of activity at pH 4.5, and optimal temperature at 55 oC. The fraction was stable at pH values between 8.5 and 10.0 and temperatures from 30 to 60 °C and from 90 to 100 °C. The EBFL-40-80 sulphate fraction had an optimum pH at 9.0, with a second peak at pH 6.0, and an optimum temperature at 55 °C, being stable at pH values between 6.0 and 9.0 and temperatures from 60 to 90 °C. The thermal stability of the EBFL-40-80 sulphate fraction changed to the range between 30 and 70 °C in the presence of the protease inhibitor phenylmethanosulfonyl fluorate (PMSF). The thermal stability of the fraction EBFL-50 acetone did not change in the presence of PMSF. The best esterification activity was observed in the presence of stearic acid after 48 h for the EBFL-50 acetone fraction.