Pure alginate film was the smoothest. A
film containing pectin showed more structural discontinuities.
That could be a result of drying conditions, chemical composition
and polysaccharide interactions. A different internal arrangement
was observed as a function of film composition. Pectin film network
is less organized than alginate film. It can be also observed
that film thickness increased when pectin content increased in
film-forming solutions. That could be closely related to differences
between water-holding ability of alginate and pectin. Similar results
were reported in pectin–soy flour films obtained in the presence
of transglutaminase showing that modified films had a
smoother surface and higher homogeneity (Mariniello et al.,
2003). Presence of pectin or other components may be responsible
for that phenomenon, because existence of an interaction between
both components is obvious. Cross sections of investigated films
showed compact microstructure.