Análise quimiométrica da influência do pH e do tween 80 em filmes de proteína de soro de leite

Abstract

The environmental impact caused by synthetic packaging and inadequate waste disposal have been one of the major concerns in the current world. As a result, new materials with lower potential pollutant have been studied in order to produce biodegradable packaging. The aims of this research is to produce biodegradable films based on whey protein at different pHs and concentration of Tween 80. Films were characterized upon whey protein initial concentration, mechanical properties, water solubility, and water vapor permeability. A statistical experimental design 22 was used to verified the significant effect of pH (5.5, 7.0, and 8.5) and Tween 80 concentration (0, 4.5, and 9%) upon said properties. Films at pH 5.5 showed aggregates of particles not soluble distributed on the surface of the films while films at pH 7.0 showed several holes that were naturally produced during water evaporation. Films with pH 8.5 were the ones that showed a homogeneous texture. The variable pH was the unique variable that had a significant effect on mechanical properties of the films. Films at pH 8.5 showed the greatest percent elongation, 30.64%, and the greatest breakage resistance, 1.28 MPa. The interaction between pH and Tween 80 had a significant influence on solubility of the films. The lower values of solubility were related to pH 8.5 and absence of Tween 80. It was not possible to verified the effect of pH and Tween 80 upon water vapor properties of the films because they showed cracks when the analyses were run.