The use of meat myofibrillar proteins for edible film production involves initially the extraction of the macromolecule, since it is not commercially available. Thus, the objectives of this work were the extraction and characterization of bovine meat myofibrillar proteins, in laboratory scale, and the elaboration and characterization of the microstructure of these films. The myofibrillar proteins were extracted form the Semitendinosus bovine muscle, post rigor mortis, using a differential centrifugal technique in buffer solution, with different saline concentrations, modifying the Eisele and Brekke [13] method. The proteins were lyophilized (PML) and analyzed for protein, fat, mineral, ash and moisture content. The amino acid composition was determined by ionic exchange chromatography and the eletrophoretic profile was done using SDS-PAGE. Films having 1g of PML/100g of solution, 60g of glycerol/100g of proteins and pH maintained at 2.8 with acetic acid were used for the microstructure study using a scanning electronic microscope. The PML which presented 84.3% of protein content, was composed of several fractions of myofibrillar proteins, with emphasis for the myosin and actin fractions, according to the SDS-PAGE results. From the amino acid composition values, was verified that the main energetic contribution came from covalent links (58.3%), followed by the ionic interactions (35.7%). The films microstructure showed a poorly homogeneous structure, but with a protein matrix compact and smooth.
biopolymers; amino acids; electrophoresis; edible films; microstructure
