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Bone-Bound Glucoamylase as a Biocatalyst in Bench-Scale Production of Glucose Syrups from Liquefied Cassava Starch

Abstract:

This research assesses the bench-scale application of a non-conventional support, bone particles, for glucoamylase (GA) immobilization and its subsequent use in cassava starch hydrolysis. Upon determining the appropriate conditions to immobilize GA onto chicken bone particles, such as pH, ionic strength, particle size, and enzyme load, bench-scale immobilization of commercial GA without further purification was performed. Under the selected conditions, 270 GA units per gram of support were adsorbed. Optimal temperature and thermal stability of immobilized GA were only slightly different from those of the free enzyme, while optimal pH became more acidic by about one unit. The feasibility of the use of this immobilized biocatalyst for high glucose syrup production from liquefied cassava starch, at bench scale in batch process using a stirred-tank reactor, was demonstrated. Repeated use of the GA-bone derivative showed that similar conversions to those achieved with soluble enzyme (dextrose equivalent=98) were reached until the third batch and over 90% until the 25th batch. © 2008 Springer Science + Business Media, LLC.