Mechanical and structural characterization of whey protein concentrate/montmorillonite/lycopene films

BACKGROUND The production/characterization of nanocomposites based on whey protein concentrate (WPC) and montmorillonite (MMT) with lycopene as functional substance is presented and their potential use as alternative biomaterials in foodstuff applications is discussed. A full factorial design with varying levels of MMT (0 and 20 g kg−1) and lycopene (0, 60 and 120 g kg−1) was used. The mechanical properties (tensile and puncture tests), thermal stability, Fourier transform infrared vibrational spectra and film morphology of the resulting materials were evaluated. RESULTS Lycopene and MMT nanoparticles could be successfully included in WPC films using the casting/evaporation method. The films were flexible and homogeneous and a uniform dispersion of the components was achieved. CONCLUSION Inclusion of 20 g kg−1 of MMT in the polymeric matrix improved both mechanical and thermal properties. Lycopene at the tested concentrations, besides its red coloring ability, did not promote any detectable interference in the structural or physical properties. These findings are important in devising applications and open a new perspective on the use of these materials in bioactive packaging processing. © 2017 Society of Chemical Industry