| Summary: | 碩士 === 東海大學 === 食品科學系 === 83 === The studies were focused on: firstly,investigation of opti- mum
conditions for immobilization of chitosanase on crab chitin and
on chitopearl; secondly,comparison of batch-wise or contin-
uous-type hydrolysis of chitosan by the immobilized
chitosanases ;and thirdly,comparison of the effect of chitosan
and chitosan hydrolyzates on the growth of some bacteria. The
suitable conditions for immobilizing chitosanase on chitin were
using 40-60 mesh chitin particle size,and treating it with
0.75% glutaraldehyde solution before mixing with 3.6 mg protein/
g chitin..As to the suitable conditions for immobiliz- ing
chitosanase on chitopearl were using 4.8 mg protein/g
chitopearl. The suitable conditions for the batch-wise
hydrolysis of chitosan with the chitin-immobilized chitosanase
were a react- ion temperature of50℃,and an immobilized enzyme
concentration of 2.0%(dw/v).As to the continuous process,in a
column reactor packed with 2.0g(dw) of the immobilized enzyme,
the most suit- able conditions for hydrolyzing chitosan were a
flow rate 10mL /hr and reacction temperature of 30℃. As to the
antibacterial effect of chitosan and chitosan hydrolyzates on
some bacteria(E.coli,S.typhi,S.sureus,B.cereus) ,a chitosan
hydrolyzate of 5% hydrolyzing degree showed an eff- ect
stronger than chitosan and chitosan hydrolyzates of 10%,20%
,30% hydrolyzing degree,orderly,at the same concentration.Alth-
ough chitosan hydrolyzates of higher hydrolyzing degree showed
lower antibacterial effect than one of 5% hydrolyzing degree
and chitosan at low concentration,they presented good effect at
higher concentration.On other hand,chitosan hydrolzsates of 10%
(or higher)hydrolyzing degree had water-soluble,low viscous,
astrigentless taste properties those were usefully in food
applications.
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