Abstract:
|
Corn starch (native and phosphorylated)
and potato films containing glycerol as plasticizer, and bagasse
sugar cane as fiber, were produced by extrusion-calendering
process, and characterized for the mechanical
properties (tensile stress at rupture rr, elongation at break
eb, and Young’s modulus E), water disintegration index
(WDI), water absorption capacity (WAC), and luminosity.
The evaluated processing variables were: feed moisture,
fiber content, and type of starch. The response surface
methodology was applied to analyze, and the model of significance
was justified by a variance analysis (F-test). The
inclusion of fiber provides a mechanical reinforcement to
the starch matrix favoring the elongation at break (eb) in
thickness films (280–350 lm). Samples formulated with potato starch within the values of feed moisture 18.25, 20.5,
and 5 wt % of fiber content, showed an increment in values
of tensile stress at rupture (3.80–4.4 MPa) and Young’s
modulus (78.47–68.04 MPa). Corn starch films with high
fiber content (10%) and low feed moisture (18.25%) values
showed a decrement in elongation at break (12.93%). WAC
and WDI were low with minimum and intermediate levels
of feed moisture and fiber content (0–5%). Luminosity values
were an indicative that do not exist degradation in film
materials due to condition extrusion process used. |