Capability of immobilised glucoamylase on mesostructured cellular foam silica to hydrolyse tapioca starch

Abstract

Mesoporous size siliceous-based materials have been associated with immobilisation of free glucoamylase and soluble starches hydrolysis. As ethanol and other chemicals can be produced from insoluble feed such as tapioca, understanding of glucoamylase immobilised on mesostructured cellular foam (MCF) silica to hydrolyse the starch is required. To get the knowledge on this process for development of a large-scale operation, free glucoamylase SQzyme AGP was immobilised on MCF silica (9.2T-3D) by direct adsorption and used the product to hydrolyse tapioca. The free enzyme was able to be immobilised onto the carrier with the efficiencies of 39.20-84.84% where the operational factors of temperature, agitation speed and pH affected the immobilisation process highly. During the enzymatic hydrolysis, effects of temperature and agitation speed were high. The dextrose equivalent (DE) values of 1.21-81.70% were obtained. The optimum temperature and agitation speed were 70°C and 140 rpm. Other factors such as buffer pH, starch concentration and enzyme unit activity showed low effects on the hydrolysis process. Excellent DE were obtained at the conditions of pH, tapioca concentration and enzyme unit activity of 4.6, 3 mg mL−1 and 2351 U, respectively.