Monitoring of acid-induced coagulation of dromedary and cow's milk using different complementary analytical techniques

Abstract

This study investigates the acid-induced coagulation of dromedary and cow's milk using rheological, light backscattering, and FT-MIR spectroscopy techniques. Throughout the acid-induced coagulation process, dromedary milk exhibited higher values of pH than cow's milk. Indeed, pH values of milk attained values of 3.94 and 3.84 at the end of the coagulation for dromedary and cow's milks, respectively. Rheology measurements showed that, throughout the acid-induced coagulation, dromedary milk significantly presented lower values of storage modulus (G′) and loss modulus (G″) than cow's milk. The type of milk significantly affects the curd firmness of acid milk gels. Indeed, the lowest curd firmness of dromedary (8.71 Pa) and cow's milk (11.37 Pa) was observed at pH = 3.8, and 3.94, respectively. The delta backscattering (ΔBS) showed a sigmoidal increase at the initial steps of acid-induced coagulation of dromedary milk.