  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.
