Characterization of dextrin prepared by common neutral and thermostable α-amylases
2010
SUN, JUNLIANG | Li, Xinhua | Zeng, Jie | LIU, BENGUO | Li, Guanglei
With corn starch as raw material, dextrin was prepared by the combined application of common neutral and thermostable α-amylases in this study. The effects of reaction temperature, reaction time, addition of common neutral and thermostable α-amylases on dextrose equivalent (DE)-value of dextrin were investigated. The obtained dextrin with a DE value of 20.43 was evaluated for morphology, crystallography, particle size distribution and thermal property by scanning electron microscope, X-ray diffractometer, light scattering particle size analyzer and thermogravimetric analyzer. The results showed that the amorphous regions in the core part of corn starch were completely hydrolyzed and only the fractured crystalline surface remained. The particle size of the dextrin change significantly compared with the starch. The average particle size reduced from 15.7 μm for unmodified starch to 7.98 μm for the dextrin. Also, the thermal stability of the dextrin was superior to that of the starch. By the combined application of common neutral and thermostable α-amylases, the time of enzymatic hydrolysis and the addition of enzyme could be significantly reduced. The preparation and characterization of dextrin in this study could be used to improve the current process of dextrin.
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