| dc.description.abstract | Several types of thin films are widely used to protect foodstuff, but thin film with
antimicrobial activity and edible film characteristic is still limited to develop. In this work
has been performed the preparation of thin film of alkaline earth element chelate with
alginate-chitosan, through reactions between 0.1 M CaCI2, 0.1 M SrCI2 and 0.1 M BaCI2
with alginate-chitosan ionic interaction. These products were characterized by
physicochemical measuring of Scanning Electron Microscope (SEM), Differential
Thermal Analysis (DTA), Fourier Transform Infra Red (FT-IR), load, stroke, percentage
of elongation and its antimicrobial properties.
Surface morphology measuring by SEM showed that the smoothness to roughness
of surfaces were in order Ca alginate-chitosan, Sr alginate-chitosan and Ba alginatechitosan.
This order was agree with the ionic size from large to small that is Ca2+, sr2+
and Ba2+ ions.
Thermogram results of DT A showed that exothermic thermal degradations were
330; 430 and 440°C for thin film of Ba alginate-chitosan, Sr alginate-chitosan and Ca
alginate-chitosan respectively. These mean that smaller ionic radius from Ba2+ ion to sr2+
and Ca2
+ ions resulted larger degradation temperature.
From FT-IR spectra of thin film chelates of Ca alginate-chitosan, .Sr alginatechitosan
and Ba alginate-chitosan showed that there were no new added functional
groups. It means that there was no reaction between alginate and chitosan, but it was only
ionic interaction.
From measuring of loads resulted 0.03; 0.02 and 0.09 kgf, stroke values were
15 .89; 11.95 and 9 .13 mm/minute, while percentage of elongations were 10.66; 8. 70 and 7 .04 % for Ca alginate-chitosan, Sr alginate-chitosan and Ba alginate-chitosan. These
mean that the higher ionic radii of alkaline earth elements formed chelates with alginatechitosan,
the lower of its elasticity.
Based on characteristic measurement by physicochemical resulted that alkaline
earth elements Ca, Sr and Ba which have empty d orbitals, capable to form chelates with
alginate-chitosan ionic interactions. Occurrence of these thin films because of
complexation between alkaline earth elements with guluronat block of alginate.
In the measuring simple biochemistry toward microba in white bread which
covered with each thin film were found four bacteria species and one fungi species based
on types and their cell morphologies. The largest number of microbial was microbial was
in white bread which covered by Ca alginate-chitosan, then followed by Ba alginatechitosan
and Sr alginate-chitosan. These mean that thin film antimicrobial activity of Sr
alginate-chitosan chelate was stronger than that of Ba alginate-chitosan followed by Sr
alginate-chitosan.
Based on characteristic measurement which has been performed by microbiological
test, it was clearly that each thin film of alkaline earth alginate-chitosan was very
potential to use as thin film which has antimicrobial activity. In order to know which one
of these thin films of alkaline earth element alginate-chitosan that can be used as edible
film, therefore it is necessary to determine the safety of the product. | en_US |
