The effect of micro-structure of CMC on stability of milk beverage

In this paper, two types of carboxymethyl cellulose samples (CMC _e and CMC _m), which served as stabilizer to improve the taste and the shelf life of milk beverage, were prepared at different bath ratio and reaction media system. The influencing factors of samples' discrepancy structure with the ways of preparation were invested. After this, its application basic properties of the samples were searched in milk beverage. The macromolecule structure and morphologies and application performances were analyzed by NMR and SEM. The effect of molecular structures and their acid salt tolerance property of two CMC on milk beverage such as sedimentation ratio and stability of milk micelle were also investigated. The results showed that the distribution of the CH ₂COO- group on anhydroglucose unit (AGU) of CMCe obtained at low bath ratio in ethanol was C ₂> C ₆> C ₃, whereas C ₆>C ₂>C ₃ which showed the highest substitution in C ₆ position, was observed in CMC _m prepared in mixed isopropanol and ethanol at high bath ratio. In comparison with CMC _e at same viscosity, the CMC _m showed higher ratio of acidity to viscosity (AVR), higher temperature resistance, lower precipitation ratio (AVR) and better stability. As shown in SEM image of treated milk powder made from milk beverager, the structure of milk protein with CMC _m formed continuous network and homogeneous morphology. However the structure of milk protein with CMC _e showed tendency of aggregation.