DEVELOPMENT AND CHARACTERIZATION OF AN ACTIVE BIODEGRADABLE FILM WITH ANTIOXIDANTS (ALPHA-TOCOPHEROL) FROM WHEY PROTEINS

Rationale: Whey proteins are a by-product of the dairy industry that recently have been considered as a source of contamination of the natural effluents. Several studies have shown their excellent properties for the manufacture of films and coatings with the addition of antioxidants, and have been considered as an ecological alternative that would reduce the use of synthetic polymers while ensuring the preservation of some foods. Objective: The main objective of this study was to characterize the mechanical, optical, morphological, and biodegradation properties of an active film obtained from whey cheese proteins and the natural antioxidant alpha-tocopherol, for its use in the preservation of different foods. Methods: The films were developed from a 10% solution (w/w) of whey protein concentrate (WPC) in water, 7% w/w of glycerol as plasticizer, and a-tocopherol at 1 and 2% (w/w) dissolved in ethanol were added. Mechanical properties were evaluated under the ASTM D882-01; furthermore, the films were analyzed by spectrophotometry, scanning electron microscopy (SEM) and biodegradation analysis was performed by controlling of mass loss. Results: The obtained films showed adequate physical appearance and slightly brown coloration. Tension decreased similarly with the addition of a-tocopherol at 1 and 2%; however, the highest elongation was for films with a-tocopherol at 1%. The films showed excellent barrier property in the range of 300-400 nm of the UV region. The SEM photographs showed the droplets of the antioxidant on the surface of the film, and the biodegradation of films was confirmed in the evaluated films. Conclusion: Mechanical, optical, morphology, and biodegradation properties of the films were directly affected by the amount of a-tocopherol used in the formulation. The incorporation of the natural compound in the films of protein has potential use to extend shelf life of fatty foods.