So far, there are more than 60 kinds of food thickeners for the food industry in the world, mainly used to improve and stabilize the physical properties or form of food, increase the viscosity of food, give food a sticky, smooth and good taste. They also play a role in thickening, stabilizing, homogenizing, emulsifying gel, masking, flavor correction, aroma enhancement, sweetening, and so on. There are many types of thickeners, which are divided into natural thickeners and chemically synthesized thickeners. Natural thickeners are mainly obtained from plants and animals. The chemically synthesized thickeners are CMC-Na, malonyl alginate, and so on.
CMC thickener is one of the most important excipients in the food industry, which mainly plays the role of stabilizing the food form in food processing, such as keeping the suspension slurry stable, maintaining stable cleanliness, and stabilizing the emulsion system. Besides, it can improve the tactile feel of food and the stability of the states of color, aroma, taste, and liquid of processed food. The prominent role of CMC thickener in food is mainly manifested in:
CMC thickener is all hydrophilic polymeric substances, which has a great viscosity when dissolved in water, giving the system a thick feel. As the viscosity increases, the dispersion phase in the system is less likely to aggregate and coalesce, thus stabilizing the dispersion system. Most thickeners have the function of surfactants, which can be adsorbed on the surface of the dispersed phase, making it hydrophilic for easy dispersion in the water system. The thickener's molecular weight distribution, concentration, the temperature of the solution, and the pH machine shear rate, can all affect the viscosity of the solution.
Some thickeners, like solutions such as gelatin and agar, are viscous fluids in warm conditions. As the temperature decreases, the solution molecules join into a mesh structure, where the solvent and other dispersing media are all contained, and the whole system forms a semi-solid, namely a gel, which has no mobility. The processing of many kinds of food such as jelly, custard and so on takes advantage of this property of thickeners. Some ionic types of water-soluble macromolecular thickeners, such as sodium alginate, can form gels in the presence of highly valued ions, with nothing related to temperature. This has facilitated and aided the processing of many kinds of specialty food. It is worth noticing that not all food thickeners form gels. Also, their gelatinous nature, when applied to the food system, cannot be substituted for each other. The reason for this is that the characteristics of the various thickeners, such as gel formation pattern, quality, stability, taste, and acceptability, are not identical.