Multi-pass high pressure homogenization of commercial enzymes: Effect on the activities of glucose oxidase, neutral protease and amyloglucosidase at different temperatures

Abstract

This study evaluated the residual activities of amyloglucosidase (AMG) at 65 and 80 °C, glucose oxidase (GO) at 50 and 75 °C and neutral protease at 20 and 55 °C after 3 passes of high pressure homogenization (HPH) at 150 MPa and 200 MPa (neutral protease and AMG) and at 100 and 150 MPa (GO). The results for AMG and neutral protease showed that the improvement in maximum enzyme activity was reached after one pass at 200 MPa, with an increment in the AMG residual activity measured at 80 °C (activity increased from 13% to 21%) and in the neutral protease residual activity at 20 °C (activity increased from 50% to 64%). However, the multiple passes caused no improvement in the activities of the enzymes. To the contrary, the results obtained for GO showed that HPH at 150 MPa continuously improved the activity at 75 °C up to three passes, reaching an activity three times higher than the native sample. Additionally, it was observed that two passes of GO at 100 MPa resulted in the same level of GO activation reached after a single pass at 150 MPa. These results suggest that multiple HPH effects differ for each enzyme evaluated and can be applied to improve GO activity. Enzymes can be used in several areas of food industry. However, the price of enzymes and their low stability limits the enzymes' application in food industry. The HPH is suggested to process the enzyme prior to application, to increase enzyme activity mainly at non-ideal temperature. Therefore, the application of high pressure homogenization to improve enzymes activity can expand the range of enzyme uses.