Abstract: Proteins regularly used in foods such as soy protein isolate (SPI) and whey protein as well as their hydrolysates were selected as the experimental subjects to explore the correlation and applicability of different methods for determining protein hydrophobicity. The results indicated that ANS (1-anilinonaphthalene-8-sulfonic acid) fluorescent probe method was an appropriate method for measuring the hydrophobicity of various kinds of proteins and their hydrolysates (DH < 23); CPA (cis-parinaric) fluorescent probe method was not suitable for determining proteins with relatively weak hydrophobicity; reverse-phase high performance liquid chromatography method was a good method for proteins with relatively moderate and strong hydrophobicity; the linearity of surface tension method had shortcomings when the hydrophobicity was characterized by gas-liquid interface parameters. All of these investigations provided a theoretical basis for determining hydrophobicity in food protein systems.

Key words: protein, hydrophobicity, fluorescent probe method, high performance liquid chromatography (HPLC), surface tension