physicochemical and functional properties of crawfish chitosan as ...

CHAPTER 5
SUMMARY AND CONCLUSIONS
Throughout the literature on chitosan, the main emphasis is on its quality and
physicochemical properties which vary widely with crustacean species and preparation methods.
Upon this emphasis, this research study was attempted to prove or dispute these views by
conducting similar studies and monitoring the modification of processing protocols of the
chitosan production using crawfish shell waste, and to determine whether such modifications had
any effect on the various physicochemical and functional properties of chitosans. From our
results, we found that specific physicochemical and functional properties of chitosan have
affected by process protocol alteration/modification.
Change/modification of decoloration (DC) step among four steps for the production of
crawfish chitosan affected the physiochemical and functional properties. DCMPA and DMCPA
resulted in an increase in molecular weight and ash, respectively. In contrast, DMPCA yielded
chitosan with low-viscosity. The most notable change observed with DMPAC was a light brown
degraded colored chitosan that exhibited properties of a weak polyelectrolyte. When the process
of deacetylation changed its order from the standard method, significant degradation of the
chitosan structure occurred, because the process was a very harsh treatment with concentrated
sodium hydroxide (40-50%) usually at 100 o C or higher for 30 min. Similarly, when chitosan
process started with Deacetylation (DA), the sudden formation of gel, an unknown white
polymer with very poor yield was obtained and the process considered unsuccessful. Thus, it is
suggested not to conduct this process step for chitosan production.
In a similar manner, when demineralization (DM) and deproteinization (DP) were
reversed during production, the results did not show much difference except for the low
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