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Carboxymethylcellulose, or sodium carboxymethylcellulose, is a food additive that has the properties of thickening, emulsifying, shaping, keeping food fresh, and can be used in place of food additives such as gelatin, agar, and sodium alginate. For the first time, carboxymethyl cellulose was obtained in 1918; it has been commercially produced since 1920. Under modern conditions, it is synthesized by chemical reactions from non-food natural raw materials.
physical properties
When dry, carboxymethyl cellulose is a white or slightly yellowish, amber or grayish powder, odorless and tasteless. Carboxymethylcellulose is readily soluble in water but insoluble in most organic solvents such as ethanol, methanol or acetone. It can be dissolved in mixtures if the organic solvent content is less than 40%.
Carboxymethylcellulose is hygroscopic, that is, it has the ability to retain moisture, and also has excellent water-binding ability. The amount of water absorbed depends on the viscosity and type of substitution in the reaction, as well as on the temperature. The lower the degree of substitution and the higher the viscosity, the higher the water absorption capacity of the substance. The hygroscopic properties are partly responsible for the success of CMC as a food and drug supplement.
Synthesis of carboxymethyl cellulose
Carboxymethylcellulose is synthesized by the alkaline-catalyzed reaction of cellulose with chloroacetic acid. During this reaction, the polar (organic acids) carboxyl groups make the cellulose soluble and chemically reactive. The functional properties of CMC depend on the degree of substitution of the cellulose structure (the number of hydroxyl groups involved in the substitution reaction), as well as the length of the cellulose chain structure and the degree of clustering of carboxymethyl substituents.
After the initial reaction, the resulting mixture gives approximately 60% carboxymethyl cellulose plus 40% salts (sodium chloride and sodium glycolate). This product is the so-called technical CMC, which is used in detergents. Another purification method is used to remove these salts to obtain pure carboxymethyl cellulose, which is used in foods, pharmaceuticals, and toothpaste.
Use as a food additive
Carboxymethylcellulose is found in:
- chocolate milk;
- cocoa;
- dry and condensed milk;
- in front of me;
- sausage casings;
- custards;
- seasonings and spices;
- soups and broths;
- sousah
- beer, cider.
Carboxymethylcellulose sodium salt is often added to foods as a stabilizer and is generally recognized as a safe ingredient. It is used to make ice cream, due to the ability to hold the mixture in a certain shape. It is also added as a filler, emulsifier, firming and gelling agent, humectant and thickener.
Use as a thickener
Carboxymethylcellulose is added to some products as a thickener and dispersant. As a thickening agent, it facilitates uniform dispersion of the ingredients throughout the mixture. It helps keep solids suspended in liquids and acts as an emulsifier to keep lotions and creams at the right consistency.
It is also an ingredient in many non-food products such as laxatives, diet pills, water-based paints, detergents and various paper products.
Adding sodium carboxymethyl cellulose to a liquid changes its viscosity. This property is achieved by the fact that carboxymethylcellulose molecules bind to each other, water compresses and breaks the bonds. The viscosity, or resistance to spillage, of a liquid depends on the amount of carboxymethyl cellulose sodium salt added. Carboxymethylcellulose can be used to make thick, slow pour gels, artificial tear effect eye drops, and in the oil industry as a drilling fluid ingredient, where it acts as a viscosity modifier and water retaining agent.
Safety of carboxymethyl cellulose
Carboxymethylcellulose is generally considered to be a fairly safe dietary supplement. An allergic reaction to this dietary supplement has been reported in one woman in the form of anaphylactic shock, but this is an exception. It has no nutritional value or benefit to the body because it is not absorbed in the digestive system, it is a dietary fiber, but it can be a very useful food additive for all kinds of foods.
The addition of sodium carboxymethyl cellulose to food can reduce the cost of food production, improve the taste of food and increase its shelf life, so it is an ideal additive in the food industry, which can be widely used in the production of various kinds of solid and liquid drinks, candy, candy, cake , instant noodles, convenience foods, soy milk and fruit juice. Therefore, there is no reason to avoid carboxymethyl cellulose, or to limit its intake.