Summary: | 碩士 === 國立臺灣大學 === 化學工程學系 === 86 === This study mainly investigated the hydrolysis reaction of amy-
lases (β-amylase or isoamylase) under the supercritical carbon
dioxide. The results were compared with those under
atmospheric pressure. Moreover, multiple enzymes of β-
amylase and isoamylase was also evaluated. We found that the
optimal conditions to be 50℃, and pH is 4.5 under atmospheric
pressure.
Experimental results indicated that the optimal pH value for
β-amylase reaction under atmospheric pressure was 5.2, compared
with the value of 5.7 in the supercritical carbon dioxide system. For
multiple enzymes system, the optimal pH was 4.5 under atmospheric
pressure but became 5.0 in the supercritical carbon dioxide system.
With soluble starch as reaction substrate, the optimal agitation was
250 rpm under atmospheric pressure but 150 rpm in the supercritical
carbon dioxide. On the other hand, the optimal agitation was 750 rpm
under atmospheric pressure but 500 rpm in the supercritical carbon
dioxide system when amylopectin or starch was as substrate.
The comparison of reaction rate of β-amylase and isoamylase
between under supercritical carbon dioxide system and in atmospheric
pressure system was also evaluated . The results showed that in low
viscosity substrate such as soluble starch, the reaction rate in the
supercritical carbon dioxide system was quite similar with in the at-
mospheric pressure system. When hydrolyzing high viscosity sub-
strate such as amylopectin and starch, the reaction rate became
superior in supercritical carbon dioxide system.
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