| dc.description.abstract | Bacterial cellulose (BC)/biopolymer composites were prepared in-situ by
supplementing gelatin, agar, pectin and chitosan with different concentrations of
0.1%, 0.2% and 0.3% into BC-producing culture medium. The physical, chemical
and mechanical properties of films were evaluated. The presence of biopolymers
interfered with the growth of bacteria and the formation of BC structure resulting
in the difference of BC yield from that of pure BC. Within each type of modified
medium, BC incorporated with 0.3% gelatin, 0.1% agar and 0.2% pectin gained
the highest BC yields so the films formed from these combinations were used to
test film properties, while the obtained amount of BC/chitosan was negligible. Total
sugar consumption was significantly different among BC-producing media. SEM
images showed that the incorporation with agar and pectin improved the
smoothness and tightness of film matrices. Through FTIR spectra, both BC and
BC/biopolymers films presented a similarity in the functional groups; however
small changes in peak intensity and position suggested that certain interactions
between BC and biopolymers occurred. All BC films expressed to be fairly light and
tend towards green and yellow, in which BC/gelatin and BC/pectin films were
darker in color but less opaque than the others. In term of hydrophilic properties,
modified BC films showed higher level of water solubility, swelling behavior and
water vapor permeability compared to pure BC film due to hydrophilicity of
biopolymers, expect for WVP of BC/agar. The mechanical properties of the films
were determined by their hardness, descending order was BC/agar, BC/pectin, BC
and BC/gelatin, respectively. This study evaluated some of the basic properties of
films, indicating benefits and limitations of BC/biopolymers as a potential
packaging material. | en_US |
