1. Film Properties
1.1 Tensile Strength and Elongation of Films
Tensile Strength and percentage of
elongation of chitosan film without orange essential
oil was 32.06 MPa and 4.87%, respectively (Table 1).
Film tensile strength reduced while percentage of
elongation increased as increasing orange essential
oil concentration. Addition of orange essential oil
acted as a plasticizer or a lubricant in the film matrix,
which increased film flexibility. Since chitosan film
alone was very fragile and difficult to apply on food
as a wrapper or packaging film. Therefore,
incorporation of orange essential oil could provide
the advantage to this application. Zivanovic et al.
(2005) also observed the same trend in which the
addition of oregano oil into the chitosan film
decreased tensile strength but increased elasticity of
the films. While Sánchez-González (2010) reported
that the lower tensile strength and percentage of
elongation when they added bergamot essential oil
(BO) into chitosan film. They explained that this could
be explained by discontinuities in the polymer matrix
introduced by the BO incorporation and by changes
in the polymer chain interactions when oil
components are present, which lead to a weak
mechanical response. The contradiction could be
due to the concentration of essential oil used in
chitosan matrix.