Methyl cellulose is a polysaccharide chemical compound, the main component of plant structure and an abundant and important source of complex carbohydrates. It is the methyl ether of cellulose produced synthetically from cotton fibres or by etherification of alkaline cellulose with methyl chloride to form cellulose ethers.

It is a chemically modified derivative of cellulose, produced through the methylation of natural cellulose. It is widely used in the food, pharmaceutical, and cosmetic industries as a thickening agent, emulsifier, stabilizer, and suspending agent. Methylcellulose is valued for its gel-forming properties and its ability to create viscous solutions, enhancing the texture and stability of products.

Chemical Composition and Structure

Methylcellulose is produced by replacing the hydroxyl groups (–OH) in cellulose with methyl groups (–CH₃), which gives the molecule unique characteristics such as solubility in cold water and the ability to form gels at high temperatures. The degree of methylation affects the physical properties of methylcellulose, including its viscosity and gelation behavior.

Physical Properties

It appears as a white or yellowish powder, soluble in cold water but insoluble in hot water. At higher temperatures, it forms gels, making it useful in a variety of applications. It is tasteless and odorless, which makes it a versatile ingredient in many industries.

Industrial Production Process

The production of cellulose gel, commonly used as a food additive for its thickening and stabilizing properties, involves a process that modifies cellulose, a natural polymer found in the cell walls of plants. This process enhances its functionality in various food and pharmaceutical products. 

• Raw material selection and preparation. Cellulose is extracted from plant sources such as cotton or wood, which are carefully selected and prepared to ensure purity.
• Cleaning and purification. The raw cellulose is cleaned and purified to remove impurities such as resins, fats, and other natural substances.
• Chemical treatment. The purified cellulose undergoes a chemical treatment, often with sodium hydroxide and/or carbon monoxide, to break down its internal structures and increase its gel-forming capability.
• Acidification and gel formation. After chemical treatment, an acid is added to neutralize the alkali and initiate the gelation process.
• Homogenization. The cellulose gel is homogenized to ensure a uniform texture and eliminate any clumps.
• Sterilization. The gel is sterilized to eliminate any microorganisms and ensure safety for its intended food or pharmaceutical use.
• Packaging. Finally, the cellulose gel is packaged in sterile, sealed containers for distribution.

It appears as a whitish powder soluble in hot or cold water.

What it is used for and where

• Food: Ingredient listed in the European food additives list as E461, emulsifier, stabiliser, thickener, gelling agent and binder. Methylcellulose can produce interesting applications in food such as foam stabilisation, film formation in fried foods, stabilisation of fruit cake dough.

• Pharmaceuticals: In the pharmaceutical industry, methylcellulose is used as a suspending agent and binder in tablet formulations. It is also employed in laxatives as a soluble fiber that aids in improving bowel movement.

• Cosmetics: In cosmetics, methylcellulose is used as a thickening and stabilizing agent in creams, lotions, and emulsions, improving the texture and consistency of the products.

INCI Functions:

Binder agent. Ingredient that is used in cosmetic, food and pharmaceutical products as an anti-caking agent with the function of making the product in which it is incorporated silky, compact and homogenous. The binder, either natural such as mucilage, gums and starches or chemical, may be in the form of a powder or liquid.

Emulsion stabiliser. Emulsions are thermodynamically unstable. Emulsion stabilisers improve the formation and stability of single and double emulsions. as well as their shelf-life. It should be noted that in the structure-function relationship, the molar mass of the ingredient used plays an important role.

Light stabilizer. It prevents light from degrading light-sensitive components and slows down degradation reactions that have already begun. The mechanism is, in a way, similar to antioxidants and the effectiveness depends on the.complexity of the formulation and the density of the product.

Viscosity control agent. It controls and adapts, Increasing or decreasing, viscosity to the required level for optimal chemical and physical stability of the product and dosage in gels, suspensions, emulsions, solutions. 

CAS: 9004-67-5

Safety in Use

E461 is considered safe for use in food and is approved by various international regulatory bodies such as the European Union and the Food and Drug Administration (FDA) in the United States. No significant side effects are associated with its use at the recommended levels.

Excessive intake of celluloses such as E461 may be associated with high risks of cardiovascular diseases (CVD) (1).

Safety in animal nutrition.

The EFSA Panel on Food Additives concluded that methylcellulose is considered safe for all animal species. The use of methylcellulose in animal feed is not of concern for consumer safety.  The use of methylcellulose as a feed additive is considered safe for the environment. The additive is considered effective in the feeding of all animal species (1).

• Molecular Formula  C₂₀H₃₈O₁₁
• Molecular Weight    454.5
• CAS  9004-67-5
• UNII    4GFU244C4J    100 MPA.S
• EC Number   232-674-9    618-391-7
• IUPAC  (5R)-2,3,4-trimethoxy-6-(methoxymethyl)-5-[(2S)-3,4,5-trimethoxy-6-(methoxymethyl)oxan-2-yl]oxyoxane
• InChl=1S/C20H38O11/c1-21-9-11-13(23-3)15(24-4)18(27-7)20(30-11)31-14-12(10-22-2)29-19(28-8)17(26-6)16(14)25-5/h11-20H,9-10H2,1-8H3/t11?,12?,13?,14-,15?,16?,17?,18?,19?,20+/m1/s1
• InChl Key      YLGXILFCIXHCMC-JHGZEJCSSA-N
• SMILES  COCC1C(C(C(C(O1)OC2C(OC(C(C2OC)OC)OC)COC)OC)OC)OC
• MDL number  MFCD00081763
• RTECS  FJ5959000
• NCI    C29253
• RXCUI     6873
• Metabolomics Workbench   44118
• FEMA    2696

References_____________________________________________________________________

(1) Sellem L, Srour B, Javaux G, Chazelas E, Chassaing B, Viennois E, Debras C, Salamé C, Druesne-Pecollo N, Esseddik Y, de Edelenyi FS, Agaësse C, De Sa A, Lutchia R, Louveau E, Huybrechts I, Pierre F, Coumoul X, Fezeu LK, Julia C, Kesse-Guyot E, Allès B, Galan P, Hercberg S, Deschasaux-Tanguy M, Touvier M. Food additive emulsifiers and risk of cardiovascular disease in the NutriNet-Santé cohort: prospective cohort study. BMJ. 2023 Sep 6;382:e076058. doi: 10.1136/bmj-2023-076058. PMID: 37673430; PMCID: PMC10480690.

(2) EFSA Panel on Additives and Products or Substances used in Animal Feed (FEEDAP), Bampidis, V., Azimonti, G., Bastos, M.D.L., Christensen, H., Dusemund, B., Kos Durjava, M., Kouba, M., López‐Alonso, M., López Puente, S. and Marcon, F., 2020. Safety and efficacy of methyl cellulose for all animal species. Efsa Journal, 18(7), p.e06212.

Abstract. Following a request from the European Commission, the Panel on Additives and Products or Substances used in Animal Feed (FEEDAP) was asked to deliver a scientific opinion on methyl cellulose as a feed additive for all animal species. Methyl cellulose is intended for use as a technological additive (functional groups: emulsifier, stabiliser, thickener, gelling agent and binder) in premixtures and feedingstuffs for all animal species with no minimum and maximum content. A proper identification and characterisation of methyl cellulose as required for a feed additive is not available and the occurrence of potential toxic impurities cannot be assessed. The following conclusions apply only to methyl cellulose meeting the food additive specifications. The FEEDAP Panel concluded that methyl cellulose is considered safe for all animal species. The use of methyl cellulose in animal nutrition is of no concern for consumer safety. In the absence of data, the FEEDAP Panel was not in the position to conclude on the safety of methyl cellulose for the user. The use of methyl cellulose as a feed additive is considered safe for the environment. The additive is considered to be efficacious in feedingstuffs for all animal species.