The Effect of Micro-Structure of CMC on Stability of Milk Beverage

Abstract

In this paper, two types of carboxymethyl cellulose samples (CMCe and CMCm), 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 CH2COO- group on anhydroglucose unit (AGU) of CMCe obtained at low bath ratio in ethanol was C2> C6> C3, whereas C6＞C2＞C3 which showed the highest substitution in C6 position, was observed in CMCm prepared in mixed isopropanol and ethanol at high bath ratio. In comparison with CMCe at same viscosity, the CMCm 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 CMCm formed continuous network and homogeneous morphology. However the structure of milk protein with CMCe showed tendency of aggregation.