Surface hydrophobicity of commercial canola proteins mixed with κ-carrageenan or guar gum

The presence of hydrophobic patches on the protein surface can aid in its ability to adsorb at an oil–water or air–water interface. The surface hydrophobicity (S0) of canola protein isolate (CPI)-hydrocolloid (κ-carrageenan, guar gum) systems was evaluated by fluorometric testing under varied conditions (NaCl, CPI and hydrocolloid concentrations; pH) using 8-Anilino-1-NaphthaleneSulphonate as a fluorescent probe. The S0 values of CPI-hydrocolloid mixtures increased as hydrocolloid concentrations increased. High S0 values reflect increased exposure of nonpolar amino acid residues due to changes in protein structure. This effect was greater at high pH and when guar gum was used.