The objective of this work was to activate, extract and partially characterize the phytase in hybrid sunflower M734 (Hellianthus annuus). The enzyme was extracted from seeds germinated for eight days, with CaCl2 2%, fractionated with (NH4)2SO4 up to 80% saturation. The obtained crude extract was partially characterized and applied over defatted sunflower flour in order to evaluate the phytate hydrolysis. In germination, there was an increase in the phytase activity and a reduction of phytate content. The highest enzyme activity was observed from the 5th to the 8th day of germination. The phytase extracted from sunflower seeds at the 5th day of germination presented optimum activity at pH 5.2 and temperature at 55ºC. The phytase was heat stable at 50ºC for 10 minutes, and presented Vmax of 1.87 U g-1 of substract and Km of 0.29 mM, indicating high specificity to phytate. When applied over defatted sunflower flour, after eight hours of incubation the phytase hydrolyzed 92% of phytate. Sunflower seeds germination stimulates phytase activity, making easy the extraction process, in the production of phytate-free feed products.
Helianthus annuus; sunflower hibrid; phytate hydrolysis
