2.4.4. Surface hydrophobicity
Surface hydrophobicity of NAM was determined according to
the method described by Benjakul et al. (1997) using 1-anilinonapthalene-
8-sulfonic acid (ANS) as a probe. NAM was dissolved in
10 mM phosphate buffer, pH 6.0, containing 0.6 M NaCl to obtain
different concentrations and then mixed with ANS. The fluorescence
intensity of ANS–protein conjugates was measured at an
excitation wavelength of 374 nm and an emission wavelength of
485 nm using an RF-1501 spectrofluorometer (Shimadzu, Kyoto,
Japan). The initial slope of the plot of fluorescence intensity versus
NAM concentration was referred to as SoANS.