Relationships Between Hydrophobicity and Foaming Characteristics of Food Proteins

Hydrophobocity measured fluorometrically for food proteins and pure proteins using cis-parinaric acid as a hydrophobic probe had significant correlations to foaming capacity when the proteins in solution were unfolded by heating in boiling water in the presence of 1.5% dodecyl sulphate prior to fluorometric measurement. Hydrophobicity measured without unfolding, which had previously shown a significant correlation to emulsification, was not significantly correlated with foaming capacity. Two highly significant regression equations were generated: one included hydrophobicity and dispersibility and the other, hydrophobicity and viscosity as the independent variables. High hydrophobicity and viscosity and moderate dispersibility were associated with optimum foaming capacity. There was a significant negative relationship between foam stability and charge density. Hydrophobicity and viscosity were also important in foam stability.