**6. The principles of food regulation in the use of cellulose derivatives**

The Code of Federal Regulations (CFR) is an arrangement and codification of general, customary, and everlasting regulations published in the Federal Register by federal government agencies, supervisory departments, and businesses. In relation to the legal guidelines related to the consumption of special raw materials in the food industry, considerable codes have been provided that present appropriate information to industrial producers [66]. In the case of drugs for human use, such as ophthalmic demulcents, the concentrations percentage of each cellulose derivative (NaCMC, HEC, HPMC-P, and MC) has been established within 0.2 to 2.5% in accordance with the standard of 21CFR349.12 [67]. The use of ethyl cellulose in food and feed is stated in the legal standards of 21CFR172.868 and 21CFR573.420, respectively. Ethyl cellulose as food additive may be safely used in foods under the stated conditions: In clause "a"—The food additive is a cellulose ether containing ethoxy groups (OC2H5) linked by an ether bond and containing not more than 2.6 ethoxy groups per anhydro glucose unit on an anhydrous basis. In clause "b"—Ethyl cellulose is used or intended for use as a binder and filler in dry vitamin preparations, as part of protective coatings for vitamin and mineral tablets, and finally in the role of stabilizer in flavoring compounds. For the use of ethyl cellulose as animal feed, it must meet the previously stated conditions of clause "a" in the same way as in clause "b–"—its uses are presented as a binder or filler in dry vitamin preparations to be incorporated into animal feed [68, 69]. Usage rules for hydroxypropyl cellulose are provided in 21CFR172.870. This standard separates HPC with a high degree of substitution (which contains no more than 4.6 hydroxypropyl groups per anhydro glucose unit) and a low degree of substitution (which contains on average 0.1 to 0.4 hydroxypropyl groups per anhydro glucose unit). High substituted HPC may be used as an emulsifier, film former, protective colloid, stabilizer, suspending agent, and thickener according to good manufacturing practice (GMP). HPC with low substitution can be used as a binder and disintegrator in tablets or wafers containing dietary supplements according to GMP. FDA indicated that the proposed use of high-substituted HPC is safe with a minimum viscosity of 10 centipoises and for same using as a binder in dietary supplements similar to low-substituted HPC will not result in an increased intake or harm to human health under the established conditions of use and significantly it is

not expected to have different biological properties [70]. Finally, for HPC based on federal regulation of 75FR17928, there is no significant effect on the environment and thus an environmental impact statement is not required [71]. The specific labeling requirements for the use of various hydrophilic gums such as NaCMC in specific drug products are noted in 21CFR201.319 [72].

The prescribed conditions for the safe use of methyl ethyl cellulose are provided in the standard of 21CFR172.872: In clause "a"—The general formula of cellulose ether is as [C6H(10-x-y) O5(CH3)x(C2H5)y]n. In this chemical formula, x is the number of methyl groups and y is the number of ethyl groups. The average value of x is 0.3 and the average value of y is 0.7. In clause "b"—This additive composition must have the following conditions: The methoxy content shall be not less than 3.5% and not more than 6.5%, calculated as OCH3, and the ethoxy content shall be not less than 14.5% and not more than 19%, calculated as OC2H5, both measured on the dry sample. The viscosity of an aqueous solution, 2.5 grams of the material in 100 milliliters of water, at 20°C, is 20 to 60 centipoises. The ash content on a dry basis has a maximum of 0.6%. In clause "c"—The food additive is used as an aerating, emulsifying, and foaming agent, in an amount not in excess of that reasonably required to produce its intended effect [73].

The specified conditions for safely using "Hydroxyethyl cellulose film-water insoluble" for packaging food are stated in accordance with the regulation code of 21CFR177.1400. In clause "a"—Water-insoluble hydroxyethyl cellulose film consists of a base sheet manufactured by the ethoxylation of cellulose under controlled conditions, to which may be added certain optional substances of a grade of purity suitable for use in food packaging as constituents of the base sheet or as coatings applied to impart desired technological properties. In clause "b"—The optional substances that are identified as suitable in terms of food safety can be used in the base sheet of film production and coating as components of water-insoluble hydroxyethyl cellulose film. In clause "c"—Any substance employed in the production of the water-insoluble hydroxyethyl cellulose film described in this section [74].

### **7. Innovations of the cellulosic application in the food industry**

Studies discuss the interrelation between the chemical structure of cellulose and its source and its various physicochemical characteristics. Although cellulose extracted from plants has been most investigated, cellulose purified from microorganisms and animals with special structural features has received increasing attention [75].

Heretofore, enzymatic hydrolysis procedure, TEMPO oxidation reaction (2,2,6,6-Tetramethylpiperidine-1-oxyl), and carboxymethylation process have been widely used to assist in defibrillating cellulose during processing into nanocellulose, which not only helps decrease consumption of energy but also provides additional functional groups for the final products [76].

Acidic hydrolysis, which includes inorganic and organic acids, can remove and eliminate amorphous regions, resulting in cellulose nanocrystal (CNC), although highly corrosive conditions and low CNC yield are persistent issues. Through mechanical treatments such as refining, homogenization, microfluidization, sonication, ball milling, and the aqueous counter collision (ACC) technique, cellulose nanofibrils (CNF) can be produced, however, the very high input energy prohibits the commercialization of these methods [77, 78].

Bacterial cellulose (BC), a special nanocellulose derived from bacteria, has currently attracted numerous research interests. Its higher aspect ratio and larger

#### *Perspective Chapter: Cellulose in Food Production – Principles and Innovations DOI: http://dx.doi.org/10.5772/intechopen.109204*

diameter make it a promising material for food packaging applications. In order to facilitate the application of nanocellulose in food packaging, it is always processed using different manufacturing technologies, including solution casting, layer-by-layer (LBL) assembly, extrusion, coating, gel-forming, spray drying, electrostatic spinning, adsorption, with the aim of producing different forms of materials such as film, gel, coating membrane, and emulsions [79, 80].

Due to their non-toxicity, proper biodegradability and biocompatibility, high aspect ratio, low coefficient of thermal expansion, extremely good mechanical strength, and special optical properties, nanocellulose-based food packaging materials are broadly used for fruit packaging, meat products, fast foods, dairy products, and beverages. Since nanocellulose and functional fillers in cellulose-based nanocomposites provide excellent barrier and mechanical properties, antibacterial activity and stimuli-responsive performance, therefore noticeably improve food quality stability and shelf life [81, 82].

Nanocellulose and its derived nanocomposite have turned out to be a hotspot of research in food packaging due to its great properties including excessive strength, large specific surface area, excellent barrier properties and proper biocompatibility, safety, non-toxicity, and degradability. In food packaging materials, nanocellulosebased nanocomposites can be used as fresh and antibacterial packaging materials, smart packaging materials, and high-barrier packaging materials, which indicates the excessive utility potential of nanocellulose-based composites. Therefore, nanocellulose-based composites, as a type of renewable and environmentally friendly packaging material, enhance the protection and quality of food and are one of the important paths to understand the improvement of **"**eco-friendly industry**"** in the food industry [83].

Recently, biopolymer-based hydrogels have been attracting growing attention due to the fact of their promising applications in drug release, biosensors, superabsorbent materials, tissue engineering, and many others [84]. Hydrogels are water-insoluble polymers that have the ability to hold a large amount of water in their network [85, 86]. The considerable hydrophilic groups with hydroxyl, carboxyl, and aldehyde form in the structure of native cellulose or cellulose derivatives make them suitable to prepare hydrogels without difficulty with fascinating constructions and properties for biomedical and food packaging and applications [87, 88].

Regarding the progress of cellulose and its derivatives in the food industry, especially packaging, the following should be mentioned [89, 90]:


water usage, large amount of polluted wastewater, high demand for energy, and low efficiency have largely prohibited the industrially feasible production of nanocellulose. Therefore, more work efforts should be made to develop novel methods for the preparation of nanocellulose, such as those based on organic acids, which have already been shown to be a green approach (not environmentally harmful strategy) for the preparation of functionalized derivatives as nanocellulose.

