Elaboración y caracterización de películas de glicoproteínas obtenidas mediante reacción de maillard utilizando almidón acetilado y aislado proteico de suero lácteo

Acetylation of oat starch was carried at two different levels (low and medium), and characterized by proximate analysis, X-ray diffraction and scanning electron microscopy. Acetylated starches underwent Maillard reaction with whey protein isolates, yielding glycoproteins with different degree of glycosylation (high, medium and low), which were characterized by the spectrophometric o-phthalaldehyde (OPA) method. Films were made with the glycoproteins, and their physicochemical properties and mechanical were evaluated. Morphologic and X-ray diffraction analysis suggest that acetylation reaction mainly occurred in the amorphous regions of the starch granule. Glycoproteins films did not show significant changes in the mechanical property of the fracture stress, except the film elaborated with the medium acetylation level and the high level of glycosylation, presenting greater fracture stress than the other films. The results of the mechanical tests and water vapor permeability of the films indicated that the glycoproteins could be suitable as coating materials to respiration control and senescence of fruit and vegetables.