Abstract:

The structure of casein micelles from buffalo milk was analyzed by fluorescence spectroscopy with the extrinsic
fluorescent probe 8-anilino-1-naphthalenesulfonic acid (ANS) and the intrinsic fluorophore tryptophan (Trp). The results
showed that the effect of buffalo milk protein at low concentration on the structure of casein micelles was obvious. As the
structure of casein micelles was broken, the hydrophobic groups were exposed to the solvent with high protein concentration.
In addition, the structure of casein micelles was influenced evidently at higher ionic strength and lower pH level, which could
cause exposure of hydrophobic groups of casein to the solvent so that the casein micelles could be formed by the expansion
and aggregation of casein microspheres.

Key words: casein, micelles structure, fluorescence spectroscopy