Resumen:
This study considered the effect of the nopal
mucilage (NM) fraction on the physical, barrier and
mechanical properties of citric pectin-based (CP) films.
Pectin aqueous dispersion 75 mL (2.0 g/100 g water) were
mixed with 5 mL of glycerol and 20 mL of NM aqueous
dispersions at different concentrations; namely, 5, 10, 12,
14 16, 18 and 20 g/100 g water. Films containing the
highest NM content (20 g/100 g water) exhibited improved
thermal stability. The addition of NM at relatively low
concentration (0–10 g/100 g water) led to important modifications
of mechanical properties, including elongation to
break, tensile strength, and elasticity. Microstructural
analysis showed that films containing between 14 and 20 g/
100 g water of NM presented rough and fractured surfaces.
As mucilage concentration in films was increased, the
vapor water permeability decreased as result of better
internal cohesiveness of components. The modification of
the physical properties in CP films resulted from molecular
and physical interaction of its components. In general, the
combination of NM and CP for forming edible films led to
enhanced thermal stability and higher water vapor permeability,
which are prescribed properties for applications as
food packaging.
Descripción:
This study considered the effect of the nopal
mucilage (NM) fraction on the physical, barrier and
mechanical properties of citric pectin-based (CP) films.
Pectin aqueous dispersion 75 mL (2.0 g/100 g water) were
mixed with 5 mL of glycerol and 20 mL of NM aqueous
dispersions at different concentrations; namely, 5, 10, 12,
14 16, 18 and 20 g/100 g water. Films containing the
highest NM content (20 g/100 g water) exhibited improved
thermal stability. The addition of NM at relatively low
concentration (0–10 g/100 g water) led to important modifications
of mechanical properties, including elongation to
break, tensile strength, and elasticity. Microstructural
analysis showed that films containing between 14 and 20 g/
100 g water of NM presented rough and fractured surfaces.
As mucilage concentration in films was increased, the
vapor water permeability decreased as result of better
internal cohesiveness of components. The modification of
the physical properties in CP films resulted from molecular
and physical interaction of its components. In general, the
combination of NM and CP for forming edible films led to
enhanced thermal stability and higher water vapor permeability,
which are prescribed properties for applications as
food packaging.