Carboxymethyl cellulose is an anionic, linear, water-soluble cellulose ether, which can make the viscosity of most commonly used aqueous preparations change greatly. In the food industry has practical value is its sodium salt, so usually CMC refers to sodium carboxymethyl cellulose. In 1958, China first put into the industrial production of sodium carboxymethyl cellulose in Shanghai Cilu Factory.
CMC is used as an additive in food, thickening, suspension, emulsification, stability, shape preservation, film formation, expansion, preservation, acid and health care and other functions, can replace gelatin, agar, sodium alginate and pectin in the role of food production, high purity CMC is also known as fiber glue. The United States and Japan and other developed countries have been widely used in the modern food industry, such as cold products, solid beverages, fruit juice, jam, lactic acid beverages, condiments, biscuits and meat products. In this paper, the structure, properties, functional characteristics of CMC, as well as the specific application and development prospects in food are summarized.
Structure and characteristics of CMC
CMC is cellulose, caustic soda and chloroacetic acid as the main raw material made of a high polymer cellulose ether, the molecular weight of compounds ranging from thousands to millions. CMC is white or yellowish powder, granular or fibrous solid, odorless, tasteless, non-toxic.
As a water-absorbing colloid, CMC has all the characteristics of colloid. In addition, CMC solution can also be used for binders, gelling agents, stabilizers and dispersants, as well as film-forming agents.
Functional properties of CMC in food applications
Thickening
It can control the viscosity in the process of food processing, and can obtain high viscosity at low concentration, and at the same time give the food a sense of lubrication.
Water retention
It can reduce the syneresis of food and prolong the shelf life of food.
dispersion stability
It can maintain the stability of food quality, prevent oil-water stratification, and control the crystal size in frozen food.
Film-forming property
In the fried food will form a layer of glue film, can prevent its excessive absorption of oil.
chemical stability
It is stable to chemicals, light and heat, and has certain anti-mildew performance.
Metabolic inertia
As a food additive, CMC is not metabolized and does not provide heat in food.