Résumé
To evaluate the nature of the main interactions that are involved in the formation of casein gels made by the acidification or rennet coagulation of milk, we investigated the combined effects of ultracentrifugation and specific dissociating agents on protein solubilization. The method used was based on the ability of gelled proteins to resist the dissociating action of solutions of urea, sodium dodecyl sulfate, or EDTA. Results showed that hydrophobic interactions and calcium bonds were the most important forces involved in the rennet milk gel matrix; hydrophobic, hydrogen, and electrostatic interactions were homogeneously distributed in the gel formed from acidified milk.