Role of constituents on the network formation of hydrocolloid edible films

In this work, the influence of pectin surface density (qs), soy flour-to-pectin weight ratio (YSF/P) and crosslinking agent (i.e., transglutaminase, TGase) on the three-dimensional film structural network was studied by dynamic mechanical and microscopy analyses. Small amplitude oscillatory measurements proved that all films behaved as solid-like materials. Storage and loss tensile moduli of pectin-based films were not affected by ps, whereas the mechanical properties of soy flour/pectin (SF/P) based films declined as the soy flour content was increased. This trend was also confirmed when using TGase to cross-link SF/P-based films, even if the complex dynamic tensile modulus was found to be more dependent on the angular frequency. The three-dimensional structure of all films examined was well described by using Friedrich and Heymann model.