Sodium carboxymethyl cellulose, referred to as carboxymethyl cellulose (CMC) is a kind of high-polymer fiber ether prepared by chemical modification of natural cellulose. Its structure is mainly D-glucose unit through β (1→4) glycosidic bond connected components. The use of CMC has many advantages over other food thickeners.

01
CMC is widely used in food

(1) CMC has good stability

In cold foods such as popsicles and ice cream, it can control the formation of ice crystals, increase the expansion rate and maintain a uniform structure, resist melting, have a fine and smooth taste, and whiten the color.

In dairy products, whether it is flavored milk, fruit milk or yogurt, it can react with protein within the range of the isoelectric point of the pH value (PH4.6) to form a complex with a complex structure, which is beneficial to the stability of the emulsion and Improve protein resistance.

(2) CMC can be compounded with other stabilizers and emulsifiers

In food and beverage products, general manufacturers use a variety of stabilizers, such as: xanthan gum, guar gum, carrageenan, dextrin, etc. Emulsifiers such as: glycerol monostearate, sucrose fatty acid esters, etc., are compounded to complement each other’s advantages and play a synergistic role to reduce production costs.

(3) CMC has pseudoplasticity

The viscosity of CMC is reversible at different temperatures. As the temperature rises, the viscosity of the solution decreases, and vice versa; when the shear force exists, the viscosity of CMC will decrease, and with the increase of the shear force, the viscosity will decrease. These properties enable CMC to reduce equipment load and improve homogenization efficiency when stirring, homogenizing, and pipeline transportation, which is unmatched by other stabilizers.

02
Process requirements

As an effective stabilizer, CMC will affect its effect if used improperly, and even cause the product to be scrapped. Therefore, for CMC, it is very important to fully and evenly disperse the solution to improve its efficiency, reduce dosage, improve product quality and increase yield. In particular, attention should be paid to each process stage:

(1) Ingredients

1. High-speed shear dispersion method with mechanical force

All equipment with mixing ability can be used to assist CMC to disperse in water. Through high-speed shearing, CMC can be evenly soaked in water to speed up CMC dissolution.

Some manufacturers currently use water-powder mixers or high-speed mixing tanks.

2. Sugar dry mixing dispersion method

Mix well with CMC and granulated sugar at a ratio of 1:5, and sprinkle it in slowly under constant stirring to fully dissolve the CMC.

3. Dissolve in saturated sugar water

Such as caramel, etc., can accelerate the dissolution of CMC.

(2) Acid addition

For some acidic beverages, such as yogurt, acid-resistant products must be selected. If they are operated normally, the product quality can be improved and product precipitation and stratification can be prevented.

1. When adding acid, the temperature of acid addition should be strictly controlled, generally ≤20°C.

2. The acid concentration should be controlled at 8-20%, the lower the better.

3. Acid addition adopts spraying method, and it is added along the tangential direction of the container ratio, generally 1-3 minutes.

4. Slurry speed n=1400-2400r/m

(3) Homogeneous

1. Purpose of emulsification

Homogeneous, fat-containing feed liquid, CMC should be compounded with an emulsifier, such as monoglyceride, the homogenization pressure is 18-25mpa, and the temperature is 60-70°C.

2. Decentralized purpose

Homogenization, if the various ingredients in the early stage are not completely uniform, there are still some small particles, it must be homogenized, the homogenization pressure is 10mpa, and the temperature is 60-70°C.

(4) Sterilization

CMC at high temperature, especially when the temperature is higher than 50°C for a long time, the viscosity of CMC with poor quality will decrease irreversibly. The viscosity of CMC of general manufacturers will drop seriously at 80°C for 30 minutes, so instant sterilization or barization can be used. Sterilization method to shorten the time of CMC at high temperature.

(5) Other precautions

1. The selected water quality should be clean and treated tap water as much as possible. Well water should not be used to avoid microbial infection and affect product quality.

2. The utensils for dissolving and storing CMC cannot be used in metal containers, but stainless steel containers, wooden basins, or ceramic containers can be used. Prevent the infiltration of divalent metal ions.

3. After each use of CMC, the mouth of the packaging bag should be tightly tied to prevent moisture absorption and deterioration of CMC.

03
Answers to questions in the use of CMC

How are low-viscosity, medium-viscosity, and high-viscosity differentiated structurally? Will there be a difference in consistency?

Reply:
It is understood that the length of the molecular chain is different, or the molecular weight is different, and it is divided into low, medium and high viscosity. Of course, the macroscopic performance corresponds to the different viscosity. The same concentration has different viscosity, product stability and acid ratio. The direct relationship mainly depends on the solution of the product.

What are the specific performances of products with a degree of substitution above 1.15? In other words, the higher the degree of substitution, the specific performance of the product has been enhanced?

Reply:
The product has a high degree of substitution, increased fluidity, and significantly reduced pseudoplasticity. Products with the same viscosity have a high degree of substitution and a more obvious slippery feeling. Products with a high degree of substitution have a shiny solution, while products with a general degree of substitution have a whitish solution.

Is it okay to choose medium viscosity to make fermented protein drinks?

Reply:
Medium and low viscosity products, the degree of substitution is about 0.90, and the products with better acid resistance.

How can CMC dissolve quickly? Sometimes, after boiling, it dissolves slowly.

Reply:
Mix with other colloids, or disperse with a 1000-1200 rpm agitator.

The dispersibility of CMC is not good, the hydrophilicity is good, and it is easy to cluster, and the products with high substitution degree are more obvious! Warm water dissolves faster than cold water. Boiling is generally not recommended. Long-term cooking of CMC products will destroy the molecular structure and the product will lose its viscosity!