Carboxymethyl cellulose (CMC) is a water-soluble cellulose ether obtained by chemical modification of natural cellulose. Due to the poor water solubility of carboxymethyl cellulose acid structure, in order to better apply it, its products are commonly made into sodium salts with the molecular formula [C6H7O2 (OH) 2OCH2COONa] n

Application in food

(1) Application research in acidic beverages

Acidic dairy beverages have a unique sour and sweet flavor and have a wide market. However, during the production process, casein tends to aggregate and become unstable under acidic conditions. Therefore, polysaccharides are generally added to protect casein, stabilize the system, and ensure a good taste. The mechanism by which carboxymethyl cellulose sodium, as a polysaccharide, can stabilize acidic dairy beverages can be described as follows: during the acid adjustment process, when the pH value is 5.2, CMC Na begins to adsorb onto the surface of casein micelles, similar to the effect of kappa casein under neutral conditions. The electrostatic repulsion and steric hindrance of the adsorption layer maintain the stable existence of casein micelles, and CMC Na has a thickening effect, which can reduce the settling rate of protein particles. The results indicate that at low pH values, a certain concentration of sodium carboxymethyl cellulose is required; And below this concentration, the system will lose stability. At pH values of 3.6~4.6, lower pH systems require more sodium carboxymethyl cellulose for stability. Fermented acidic dairy beverages have higher requirements for stabilizers compared to acid adjusted beverages.

Acidic dairy beverages containing fruit granules require the addition of a certain amount of fruit granules to stabilize the system. The experiment showed that CMC Na is the main stabilizer for acidic dairy beverages. When CMC Na accounts for 0.4% and pectin accounts for 0.14% in the composite stabilizer, the system has better stability.

Scholars have also studied the use of carboxymethyl cellulose sodium to stabilize the system in lycopene active beverages. Research has shown that when the amount of CMC Na added is greater than 0.4%, the product has good stability, but the viscosity increases significantly at this time, so it can be used in combination with other colloids.

After optimizing the CMC Na cooling process, the viscosity of traditional acid regulating dairy beverages is always higher than that of heated products during the shelf life, providing better stability. This also provides a theoretical basis for the better application of carboxymethyl cellulose sodium in the production of acidic dairy beverages.

(2) Application in Blended Yogurt

The denaturation and precipitation of milk protein under acidic conditions has always been a key issue affecting the development of yogurt. Due to its multifunctional properties, abundant sources, and affordable price, CMC Na is commonly used as a stabilizer.

The results showed that CMC Na was greatly affected by temperature and pH value. When the amount of CMC Na added was small, the yogurt state could not be stabilized. When its content was greater than 0.4%, the yogurt state improved and the system tended to be stable; And the thickening effect of CMC Na on yogurt is relatively small at 0.05%~0.1%, while the thickening effect is significant in the range of high content (0.4%~0.5%).

(3) Application of casein lotion

Lotion is a dispersion system composed of one liquid dispersed in the form of tiny droplets in another immiscible liquid, which is an unstable system. Among numerous food gums, sodium carboxymethyl cellulose and xanthan gum have been extensively studied due to their unique functional properties. The results indicate that the combination of CMC Na and XG (xanthan gum) can make the system more stable. At a certain mixing ratio (CMC Na: XG is 1 ∶ 1, 3 ∶ 1), the total addition amount is 0.4% of the total mass of lotion, and the layering stability of lotion will increase. The layering phenomenon is not obvious when the emulsion is stored at room temperature for 2 weeks.