Application of Carboxy Methyl Cellulose (CMC)
Carboxymethylcellulose (CMC) (E466) is a modified cellulose gum (cellulose is also known as plant fibre). In foods, it is used as a stabiliser, thickeners, film former, suspending agent and extender. Applications include ice cream, dressings, pies, sauces, and puddings. It is available in various viscosities depending on the function it is to serve.
CMC tends to give clear, slightly gummy, solutions. It is generally soluble in cold water but difficult to disperse in hot. CMC is used to thicken dry mix beverage, syrups, ripples and ice cream, and also to stabilise ice cream, batters and sour milk. It gives moisture retention to cake mixes and water binding and thickening to icings.Chemistry
Carboxymethylcellulose (CMC) (E466) is extracted from plant tissue, mainly wood pulp and cotton, but because it is chemically modified it cannot be classified as a natural food ingredient. Native cellulose is inert and insoluble, but modification makes it soluble.
Nutritionally, cellulose has no calorific value; it is not digested by humans and is, therefore, very useful in low calorie products.
A wide range of types and grades is available and each is well defined in terms of performance properties.
Properties
CMC is soluble in cold water to give clear and colourless solutions with neutral flavour.
Viscosity production is the primary property of CMC.
With instant products,
sodium cmc is used to provide the required rapid build-up of viscosity, for example in powdered beverages.
The viscosity produced by CMC contributes to the stabilisation of frozen products such as ice cream, water ices and ripples. Benefits include the conservation of texture and inhibition of ice crystal formation, a slow meltdown and an improved resistance to dripping and better heat shock resistance.
The thickening effects of CMC can be used in products such as salad dressings and tomato sauces. CMC properties that make it suitable for these applications include its rapid solubility in both hot and cold water, its good water binding and good tolerance to low pH levels.
For soft drinks CMC provides body or mouth feel to low calorie drinks sweetened with intense sweeteners, to more closely match the mouth feel obtained with sucrose or glucose syrup, and to inhibit ‘neck ringing' by flavour oils in beverages.
Bakery products also benefit from incorporation of CMC. In cake mixes and batter mixes,
food additives CMC can improve the volume yield as a result of its viscosity drop during baking and improve the suspension and distribution of ingredients such as fruit.
CMC can also provide improved yields and improved moistness after storage, and be used to increase yield or retard staling and hence prolong shelf life.
Typically the dosage level of CMC used in food products is 0.1 – 0.3% w/w. It is normal to fix the dosage and change the grade of CMC used to get the target viscosity required.
