Estudo das interações dos sistemas formados a partir biopolímeros

Abstract

Interactions between biopolymers have an important influence on the properties of foods in which they are employed, and can monitor and improve their functional and organoleptic properties. In the present work, the formation of complex coacervates of biopolymers from whey protein lactoferrin (Lf) and the polypeptide-leucine (PL) with polysaccharide gum arabic (GA) was studied. In all systems studied, from data of turbidity and ζ−potential was observed that the formation of insoluble precipitates occurred below the isoelectric point (IP) of the protein and polypeptide. The presence of ions able to suspend or benefit complexation phenomenon depending on the nature of the polymers used, it was observed that certain concentrations of sodium chloride (NaCl) had a positive influence on the increase in turbidity, indicating the formation of the macromolecular complexes formed between Lf / GA and the opposite was observed for the coacervates formed between PL/GA. This fact can be seen from data of particle size. Complexes formed from polymers showed spherical microcapsules due to potential natural of encapsulation of gum arabic. It was possible to obtain stable oil-water emulsions formed from lactoferrin and ovalbumin (OVA). Emulsions containing only 3% lactoferrin were stable to aggregation at different pH in the study, the emulsions containing only 3% OVA were stable only at high pH (8.0). When the two proteins were mixed to form emulsions, we observed stable systems in intermediate pH values of the isoelectric point of proteins. In these regions the proteins presented with opposite charges and likely promoting an electrostatic complexation bond, which contributed to the stability of emulsions.