Elongations at break values obtained by tensile tests were
significantly different (p < 0.05) to those determined by quasistatic
assays, being around 60 and 17%, respectively (Table 1).
Elongation at break values corresponding to the different studied
formulations, were not significantly different (p > 0.05) among
them (Table 1). The fact that film ductility is kept almost constant
despite talc incorporation could be mainly associated to different
contributions related to talc surfaces and particle orientation. On
one side, few accessible hydroxyl groups on talc edge surface lead
20 O.V. López et al. / Food Hydrocolloids 43 (2015) 18e24to strong (hydrogen bonding) but localized talc-TPS interfacial
adhesion. On the other hand, weak interaction between talc basal
surface and starch matrix is attributed to the organophilic nature of
this surface. Both aspects along with particle basal orientation,
reported in a previous work (Castillo et al., 2013), could allow starch
chains sliding despite talc incorporation. It is important to note that
ductility is a relevant mechanical issue for film applications since it
determines the degree of allowable material deformation up to
fracture.