Chlorophyllase biocatalysis in an aqueous/miscible organic solvent medium containing canola oil

Chlorophyllase catalyzes the bioconversion of chlorophyll into chlorophyllide by replacing the phytol group with a hydrogen atom. There is an increased interest in the biotechnological application of chlorophyllase for the removal of green pigments from edible oil and its potential as an alternative to the use of the conventional bleaching technique. Partially purified chlorophyllase, obtained from the alga Phaeodactylum tricornutum, was assayed for its hydrolytic activity in an aqueous/miscible organic solvent system containing refined-bleached-deodorized (RBD) canola oil, using chlorophyll and pheophytin as substrate models. The results indicated that chlorophyllase biocatalysis could be successfully carried out in an aqueous/miscible organic system containing RBD canola oil. The presence of 20% RBD canola oil decreased the hydrolytic activity of chlorophyllase by 2.2 and 6.7 times, using chlorophyll and pheophytin as substrates, respectively. In addition, acetone acted as an activator of chlorophyllase activity at low concentrations and an inhibitor at higher ones. The optimal reaction conditions for chlorophyllase biocatalysis in the aqueous/miscible organic system were determined to consist of 20% RBD oil and 10% acetone at a 200 rpm agitation speed and at a temperature and substrate concentration of 35°C and 12.6 μM for chlorophyll, and 30°C and 9.3 μM for pheophytin.