Abstract
Chlorophyllase, a membrane glycoprotein, was entrapped in various matrices, including alginate, alginate–silicate mixed gel, TMOS‐based sol–gel, and their hydrophobically‐modified counterparts. Chlorophyllase activity was affected by the physicochemical properties of the matrix, demonstrating lower activity in organically‐modified matrices compared with the corresponding hydrophilic matrices. The advantage of adopting organically‐modified matrices to facilitate the transfer of hydrophobic substrate is likely compromised by detrimental interaction between chlorophyllase and the hydrophobic components. This hypothesis is at least partly substantiated by the negligible activity demonstrated by free chlorophyllase in hydrophobic micellar media. Even though activity yields exceeded 50% in alginate beads, the release profile reveals that alginate matrix is too porous to retain chlorophyllase. Although alginate–silicate mixed gel more effectively confined chlorophyllase in the matrix, only 16% of the activity was recovered. In contrast, inorganic sol–gel yielded a chlorophyllase preparation with mass yield above 90%, and activity yield above 50%. Doping additives did not improve activity yield, which could be explained by the lower specific surface area and pore volume, and hence possible restricted accessibility of chlorophyllase by its substrate. Water/silane ratio was found to affect the sol–gel‐entrapped chlorophyllase activity by influencing the gelation time and physical properties of the gel. Copyright © 2005 Society of Chemical Industry