Abstract

PORRAS-GODINEZ, Martín R.; PEDROZA-ISLAS, Ruth; FRANCO-RODRIGUEZ, Guadalupe  and  SAN MARTIN-MARTINEZ, Eduardo. Thermal treatment effect on wettability of edible films from whey protein isolated and mesquite (Prosopis spp.) gum. Agrociencia [online]. 2015, vol.49, n.1, pp.1-13. ISSN 2521-9766.

Edible films and coatings are used to improve the quality of food products by acting as barriers against gases, moisture and aromas, delaying reactions of deterioration and prolonging the useful life of food. To form the films, biopolymers are used alone or mixed to take advantage of the characteristics of these materials and their possible interactions for better barrier properties. In this study, films made of protein isolated from whey (WPI) and mesquite (Prosopis spp.) gum (GM) were made, and the effect of heat treatment on their wettability was assessed. Determinations were contact angle, heat transitions by differential scanning calorimetry (DSC) and the interactions polysaccharide-protein by infrared spectroscopy (FT-IR). The results indicated that heat denaturalization and an increase in the proportion of GM in the films reduced humectation properties. Enthalpy and melting temperature increased with an increase of GM in the mixtures. The FT-IR spectra confirmed the interactions protein-polysaccharide and protein-protein, by the modifications in the bands of the hydroxyl group (-OH), in the C-H, C-O, C-C bonds, and in the thiol (-SH) groups. The results of this study confirmed the potential use of WPI and GM mixtures to obtain edible films.

Keywords : Edible films; whey protein isolate; mesquite gum; humectation.

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