Enzymatic hydrolysis of sago starch

Abstract

Various enzyme hydrolysis procedures were employed in this study. A kinetic model presents sago starch hydrolysis by Bacillus licheniformis α-amylase (Termamyl 120L), Bacillus subtilis β-glucanase (Cereflo 200L) and by Bacillus pullulanase (Promozyme 200L) at temperatures of 90°C and 60°C and substrate concentration of 15% solids. Quantitation of pH, temperature and enzyme dosage in different combinations was used in standard statistical techniques of experimental design and data analysis. Determination of the degree of hydrolysis was based on freezing point depression osmometry, high-performance size-exclusion chromatography (HPSEC), differential scanning calorimetry (DSC) and X-ray diffraction methods. Computer implementation of the model allows graphical evaluation and prediction in improvement of the conditions of enzyme hydrolysis of sago-resistant starch. Liquefaction and saccharification of sago starch were performed to establish the optimum conditions of enzymatic hydrolysis in comparison with other starches. Enzyme treatment resulted in a decrease in the degree of crystallinity of all hydrolysed starch samples. C-type crystals completely disappeared at 100°C.