Calorimetric investigation of the thermodynamic basis of the effect of maltodextrins on the foaming ability of legumin in the presence of small-molecule surfactant

Abstract

In this investigation, using a combination of mixing and differential scanning calorimetry, the relationships have been clarified between thermodynamics of the intermolecular interactions, the conformational stability of the protein globule and foaming ability of the protein in the ternary mixtures: neutral polysaccharide (maltodextrins with different dextrose equivalent (DE=2, 6, 10))+globular protein-legumin (11 S globulin from broad beans)+water-dispersible ionic small-molecule surfactant that represents generally the mixture of the esters of stearic and palmitic acids with a citric acid (CITREM). In addition, it was also shown that the found peculiarities of the intermolecular interactions in the ternary mixtures are also determined by the aggregation states (monomolecular or micellar) of the small-molecule surfactant in aqueous medium. The combined calorimetric data suggest that the role of the unadsorbed maltodextrin in the foaming ability of its mixture with legumin in the presence of CITREM is principally governed, on the one hand, by the marked addition of hydrophilicity from both maltodextrins and CITREM to the protein as a result of the formation of the ternary complex, maltodextrin+CITREM+legumin, and, on the other hand, by the partial protein unfolding of the protein in the ternary (maltodextrin+CITREM+legumin) complex.