8535

DYNAMIC HIGH PRESSURE ON Rhizomucor miehei PROTEASE

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The dynamic high pressure (DHP) is capable of promoting changes in enzymes. This work studied the effect of DHP on the proteolytic activity, milk-clotting activity and stability of a commercial fungal protease. The enzyme solution processed at pressures of 0, 50, 100, 150 e 190 MPa. The proteolytic activity was measured at 35ºC / 40 min and the milk-clotting activity was evaluated by the beginning of milk coagulation after enzyme addition. Moreover, rheological assay was performed during milk coagulation to assess the storage modulus (G’). These assays were performed for 30 days after DHP process aiming to evaluate the enzyme stability at 4ºC. The results showed no differences in the proteolytic activity between processed and non-processed samples for all evaluated time. Also, the milk-clotting activity showed no differences between samples immediately after process. However, after 3 and 4 days of storage, samples processed at 0 MPa, 50 MPa, 100 MPa showed slight but significant higher milk-clotting activity (6-10%) in relation to the processed enzyme 190 MPa. On the other hand, from the 5th day of storage was not observed difference between samples. The rheological results were in accordance with the obtained for the milk-clotting activity of the fungal protease. Thus, the results suggested that the fungal protease is highly resistant to DHP process due to absence of changes in proteolytic activity and milk clotting activity (majority of days evaluated). Therefore, DHP could not be applied to change the characteristics of this fungal protease, as previously described for other proteases.