Sodium carboxymethyl cellulose additive

Structural Characteristics of CMC

CMC is a white or slightly yellow powder, granular or fibrous solid. It is a macromolecular chemical substance that can absorb water and swell. When swollen in water, it can form a transparent, viscous gel. The pH value of the aqueous suspension is 6.5-8.5. This substance is insoluble in organic solvents such as ethanol, ether, acetone and chloroform.

Solid CMC is relatively stable to light and room temperature and can be stored for a long time in a dry environment. Thickener sodium carboxymethyl cellulose is a type of cellulose ether, usually produced from short cotton linters (cellulose content up to 98%) or wood pulp, treated with sodium hydroxide and then reacted with sodium monochloroacetate. The compound has a molecular weight of 6400 (±1000). There are generally two preparation methods: the water-coal method and the solvent method. Other plant fibers are also used to prepare CMC.
 

Functional Characteristics and Applications

1. Thickening and Emulsification Stability
Edible CMC can act as an emulsifier and stabilizer in beverages containing fats and proteins. This is because CMC, when dissolved in water, forms a transparent, stable colloid. Protein particles, protected by the colloidal film, become particles with the same charge, thus stabilizing the protein particles. It also has a certain emulsifying effect, thereby reducing the surface tension between fat and water, allowing for thorough fat emulsification.
Sodium carboxymethyl cellulose additive can improve product stability because when the product's pH deviates from the protein's isoelectric point, CMC additives can form a complex structure with the protein, which enhances product stability.

2. Improved Leavening
Using CMC in ice cream can improve its leavening, reduce melting speed, impart good texture and mouthfeel, and control ice crystal size and growth during transportation and storage. The recommended dosage is 0.5% of the total amount.
This is because CMC has good water retention and dispersibility, organically binding protein particles, fat globules, and water molecules in the colloid to form a uniform and stable system.

3. Hydrophilicity and Rehydration
This functional property of CMC powder is generally used in bread production, making the honeycomb structure more uniform, increasing volume, reducing crumb shedding, and also providing heat preservation and freshness retention. Noodles with added CMC have good water retention, are more resistant to overcooking, and have a better texture.
This is determined by the molecular structure of CMC. It is a cellulose derivative with a large number of hydrophilic groups in its molecular chain: -OH groups and -COONa groups. Therefore, CMC has better hydrophilicity and water retention than cellulose.

4. Gelation
Thixotropic CMC refers to macromolecular chains with a certain number of interactions, tending to form a three-dimensional structure. After the formation of the three-dimensional structure, the viscosity of the solution increases; after the three-dimensional structure is broken, the viscosity decreases. Thixotropy is the phenomenon where the apparent viscosity change depends on time. Thixotropic CMC plays an important role in gelling systems and can be used to make foods such as jellies and jams.

5. Can be used as a clarifying agent and foam stabilizer to enhance flavor.
Food-grade thickener CMC can be used in wine production to make the flavor richer, more complex, and longer-lasting; in beer production, it can be used as a foam stabilizer to make the foam richer and longer-lasting, improving the taste.
CMC is a polyelectrolyte that may participate in reactions that maintain the balance of various components in wine. It also combines with existing crystals, altering the crystal structure and changing the conditions under which crystals exist in wine, causing sediment to precipitate.