Production, characterization and foamability of {\alpha}-lactalbumin/glycomacropeptide supramolecular structures

TL;DR

This study explores the formation, properties, and foamability of supramolecular structures formed by {}-lactalbumin and glycomacropeptide under various heat and pH conditions, revealing their potential in food applications.

Contribution

It introduces a method to produce and characterize new supramolecular whey protein structures with controllable size and foamability based on heat and pH adjustments.

Findings

Protein interactions are enthalpically driven.

Structure size varies from 4 to 3545 nm depending on conditions.

pH and temperature significantly affect foam volume and stability.

Abstract

The study of protein interactions has generated great interest in the food industry. Therefore, research on new supramolecular structures shows promise. Supramolecular structures of the whey proteins {\alpha}-lactalbumin and glycomacropeptide were produced under varying heat treatments (25 to 75 {\deg}C) and acidic conditions (pH 3.5 to 6.5). Isothermal titration calorimetry experiments showed protein interactions and demonstrated that this is an enthalpically driven process. Supramolecular protein structures in aqueous solutions were characterized by circular dichroism and intrinsic fluorescence spectroscopy. Additional photon correlation spectroscopy experiments showed that the size distribution of the structures ranged from 4 to 3545 nm among the different conditions. At higher temperatures, lower pH increased particle size. The foamability of the supramolecular protein structures was evaluated. Analysis of variance and analysis of regression for foaming properties indicated that the two-factor interactions between pH and temperature exhibited a significant effect on the volume and stability of the foam.