Functional Properties in Food Applications
As the food industry has developed rapidly, the market and applications of sodium carboxymethyl cellulose are on the increasingly growing trend. In many applications, the main roles and functions of sodium carboxymethyl cellulose are as follows.
1 Thickening and Emulsifying Stabilizing Effects
The edible sodium carboxymethyl cellulose can play a emulsifying stabilizing role in the drinks containing fat and protein. For the general soy milk, cocoa milk, peanut milk, juice milk, coconut milk, almond milk,and fruit juice soymilk, they are characterized by containing different degrees of fat and a certain amount of protein, tending to separate and float during storage, forming an unsightly “collar”, and largely affecting the appearance of products. In addition, protein is easy for condensation and separation. Especially for low-pH products, protein is bound to condense.
In order to solve these problems in the quality, an appropriate amount of sodium carboxymethyl cellulose can be added, because sodium carboxymethyl cellulose is dissolved in water to become a transparent stable colloid. The protein particles become the particles with the same electric charge under the protection of colloid film, making protein particles in a stable state. It also has a certain emulsifying effect, while reducing the surface tension between fat and water at the same time, and making fat sufficiently emulsified, so that quality problems can be satisfactorily resolved. Therefore, sodium carboxymethyl cellulose is often applied in the food industry as a thickener, making food maintain the uniform flavor, concentration and texture.
2 Effects with Protein
When the pH value is greater than or less than the isoelectric point of protein, sodium carboxymethyl cellulose can form a compound structure with protein, help to improve the stability of emulsion, and on the other hand, is also beneficial to the shape maintenance of ice cream texture. This effect enables the solubility of proteins to be extended to a certain range of pH. In addition, sodium carboxymethyl cellulose is mixed with whey protein concentrate, and can replace egg protein and skimmed milk powder to make various kinds of cakes. After adding sodium carboxymethyl cellulose, the volume of cake will be increased and the quality improved. sodium carboxymethyl cellulose also replace the egg protein in other products, such as replacing the egg protein of puddings, sauces, soup and pasty cakes.
3 Hydrophilicity and Rehydration
It can be seen from the molecular structural formula of sodium carboxymethyl cellulose that it is a cellulose derivative and that there are a large number of hydrophilic groups in the molecular chain such as -OH groups and -COONa groups, so sodium carboxymethyl cellulose has better hydrophilicity and water-holding capacity than cellulose. Therefore, used in baked food, sodium carboxymethyl cellulose enables to make food maintain a certain humidity, prevents food from syneresis and makes food maintain a certain shape and appearance. For example, adding sodium carboxymethyl cellulose into the flour for making biscuits and cakes can prevent water evaporation and aging.
4 Suspending Effects
The edible sodium carboxymethyl cellulose has excellent suspending supporting strength. Used for liquid beverages, it can make pulp, various solids or other substances suspended in the container, uniform and full, the color bright and eye-catching, and improve the taste. If it is used in combination with other edible pectins by a certain ratio to make the additive for special beverages, the effect will be better. So it is widely used in fruit teas like hawthorn nectar, fruit drinks such as orange juice and coconut juice, and vegetable juices like pumpkin juice. The addition amount of sodium carboxymethyl cellulose is generally appropriate between 0.1% and 0.4%.
5 Gelation Effects
The thixotropic sodium carboxymethyl cellulose plays an important role in the gelling system and can make jelly, panna cotta, jam and other food. The so-called sodium carboxymethyl cellulose means that there is a certain amount of interaction on the macromolecular chains and tends to form a three-dimensional structure. After the formation of three-dimensional structure, the solution viscosity shows an increase; while after breaking the three-dimensional structure, the viscosity shows a decrease. The thixotropic phenomenon is shown that viscosity changes depending on time. When the shear rate (D) is constant, i.e., D = K, the viscosity of sodium carboxymethyl cellulose will decrease with time; while the shear rate is discharged, i.e., D = 0, the viscosity will increase with time. This thixotropic behavior of solution is an important property for the gelling system (i.e. anomalous rheological systems) and very useful in food. Like jelly, panna cotta, and jam in food, CMC gel and MCC-CMC gel can be used, or used in conjunction with natural gums.
6 Structure Leavening Effects
Since it has varying characteristics and gel stabilizing effects, on the one hand it can prevent syneresis, and on the other hand can increase the leavening rate. For example, when applied in instant noodles, during the operation,it can shorten the time of kneading flour, make the product uniform and the structure improved, in addition, easily control the water, can reduce the water supply amount and the required pressure by the flour roll, so that it does not or less appear noodle breaking situations and has excellent film-forming toughness. After noodles are steamed, the noodle body is bright and the surface smooth, without adhesion, distortion and browning after heating. Since it has stronger high viscosity, in the frying process, it can reduce the oil content of instant noodles by 3% to 5%.
7 Role in Improving the Physical Properties of Food
If sodium carboxymethyl cellulose is added into jam and cream, smearing property can be improved. Besides, sodium carboxymethyl cellulose can also be used for the preservation of fruits, vegetables and eggs. 2%-3% sodium carboxymethyl cellulose solution containing carboxybenzoate can be used in the coating and drying of fruits, vegetables and eggs in order to keep the flavor and resist mildew, with preservation effects. It has strong swelling property after absorbing water, but it is not easy to digest, so can be used for biscuits and act as diet food. It has the stabilizing property, so can be used for the foam stabilizer in beer. It also has viscosity, stability and protective colloid property, etc., can be used in ice cream to improve the water retention and tissue, but the effect can be better when used in combination with thickeners such as sodium alginate. In addition, it can also be used as such solid agents as powdered fat and spices.
8 Compounding Functions
sodium carboxymethyl cellulose can be compound used with various other stabilizers (xanthan gum, guar gum, carrageenan, starch, maltodextrin, etc.), and has synergistic interaction. Generally speaking, if you want to improve water retention and prevent crystallization, sodium alginate or gelatin can be selected to make cakes delicate, smooth, delicious and with good melting resistance, and can be compounded with carrageenan or guar gum.
The refined sodium carboxymethyl cellulose has early been recognized as a safe substance by the FAO and WHO (with an acceptable daily intake of 30mg /kg per person). The refined sodium carboxymethyl cellulose recognized by Food Chemicals Pharmacopoeia, the U.S. Food and Drug Administration, can be used in food additives, has been recorded into the generally recognized as safe (GRAS) substances, and included in United States Code.