Optimization of extraction of lipase from wheat seeds (Triticum aestivum) by response surface methodology.

This work aimed to evaluate the effects of particle size, solid/solvent ratio (w/v), and reaction time on hydrolytic and esterification activities of a lipase extract from wheat seeds. The higher hydrolytic activity was 5.9 U/g with a particle size of 425 microm, solid/solvent ratio of 30:60 (w/v), and reaction time of 15 h, with maximum hydrolytic activity of 14.47 U/g after 24 h of precipitation. For esterification activity the best result was 57.88 U/g with a particle size of 425 microm and solid/solvent ratio of 30:120 (w/v) for 5 h, with a maximum value after 10 h of precipitation reaching 208.20 U/g. The partial characterization showed that the optimal pH and temperature were found to be 5.5 and 32-37 degrees C, respectively. The extract stability at low temperatures was kept after 48 h of storage in terms of esterification activity. The hydrolytic activity was kept constant at -10 degrees C during 72 h and diminished considerably after 24 h at 4 degrees C.