Interfacial Behavior of Food Proteins

Abstract

Proteins are constituted of amino acids that are linked with each other in a defined sequence and through peptide bonds to form polypeptide chains, containing up to hundreds of amino acids. Proteins are typically present in emulsions and foams, and they show an edible interfacial complex. The major challenges for food technologists are the association between the interfacial properties of proteins, and their emulsifying/foaming properties or stability of the emulsion or foam. Generally, the main reasons of proteins being good agents forming foam are: they are strongly adsorbed at the interface gas-liquid; promote good steric and electrostatic stability, the films formed have cohesive structure with a high module of rheological interface due to interactions between the adsorbed molecules. Due to non polar amino acids the proteins are adsorbed on gas-liquid interface since they have hydrophobic regions. The interfacial rheology is an indirect way for obtaining this information, determining the rate and the ratio in which the proteins are adsorbed. Interactions between proteins and other components in the liquid phase increase the total molecular weight, reducing the adsorption interactions, while others affect the activity in the interface. Many researchers still consider rheological measurements of the interface an option to understand the mechanism of formation and stability of many products such as bubbles. This manuscript provides an overview of the protein behavior at surfaces and interfaces of food systems.