**3. Behavior of cellulosic compounds in food systems**

A wide range of cellulose derivatives due to their nontoxic nature for a long time have been developed, in particular, acetate, nitrate and sulfate esters, cellulose ethers (MC, HPMC, CMC, EC, HEC, and HPC), and sodium CMC are the most broadly used cellulose derivatives for foodstuffs [32]. **Table 1** indicates the different properties of cellulose-derived compounds, which are used to achieve a specific behavior in food and pharmaceutical systems. As it turns out, the polymers of MC, HPMC, CMC, and HPC exhibit the widest range of properties. Food polymers play an essential role in food structure, food functional properties, food processing, and shelf life. The information in this field is commercially essential as it will provide a beneficial practical guideline for food improvement and industrial production. The application of each of these compounds should be considered in food systems according to the important characteristics of food such as stability, the importance of resistance to stress, maintaining product uniformity, and improving physical properties [36].

Variations of the molecular structure and size of polymer chains or networks consequences in one of kind polymers with special properties. In using each of these polymers, vital behaviors in that food system need to be identified. In a food whose stability in the aqueous phase is important, the preference of a polymer that is soluble in water will be desired. In the design of food formulations based on water-insoluble compounds, it is important to select derivatives with similar properties to the main ingredients of that formulation. Generally, in various applications of cellulose derivatives for the food systems, such as emulsifiers, stabilizers, coatings, film production, gel formation, creating adhesive, and thickening structures, these different and compatible properties of the polymer are considered. Sometimes, several polymers may be suitable for a formulation or purpose, in this situation, a polymer should be chosen that is economical and can be used on an industrial scale. In fact, in a low-scale trial and error, polymers are replaced with each other, and rheological properties and sensory evaluation or textural indicators are tested. In a food system, some positive properties of a polymer may compensate for the disadvantages of another polymer, and a more suitable structure can be created by using a combination. In the research and development departments in the food industry, the application of each of the replaceable polymers is constantly being investigated. Today, the design of stabilizers for different food products has become a profitable industry and business in the world. Many companies supplying industrial raw materials are known for introducing new stabilizing formulations in the food industry [37, 38].
