Elaboración, caracterización y comparación de películas comestibles en base a aislado de proteínas de suero lácteo (WPI)

Abstract

Increasing interest in high-quality food products with increased shelf life and reduced environmental impact has encouraged the study and development of edible and/or biodegradable films and coatings. These are an excellent alternative for food products packaging due to their biodegradable, flexible and active packaging characteristics. According to this and the large uruguayan milk production in this work WPI films were made and studied. By other side, plasticizers as glycerol and sorbitol change the protein’s properties because they easily insert within the threedimensional protein network, and used at low levels make significant changes. The objective of the present work was to manufacture, characterize and compare edible films by their mechanical properties. For that two different WPI concentrations were used (8 % and 10 %) and three different WPI/plasticizer ratios: 1,6/1; 2,0/1 and 2,3/1. The lower protein or plasticizer concentration in the films led an increase of maximum load, force at break and tensile strength at maximum and at break. The higher elongation of a 60 % was obtained with the greater quantity of plasticizer (ratio 1,6/1) and with an 8 % of WPI in the film. The mechanical properties of biofilms were compared using three ratios of WPI/plastizicer. The films made with sorbitol had bigger forces and tensile strength than those with glycerol, and with both plastizicers the higher quantity of them led a lower force and tensile strength. The elasticity reases to a greater proportion of any of the studied plastizicers. The films made with glycerol as plastizicer are more elastic than the sorbitol ones.