Cellulose

Cellulose is a complex carbohydrate, specifically a polysaccharide, which forms the primary structural component of plant cell walls. It consists of long chains of glucose molecules linked by β(1→4) glycosidic bonds, making it an insoluble substance with a high fibre content. Due to its molecular structure, cellulose is not digestible by the human body, but is a type of insoluble fibre that promotes digestion through increased bowel movements.

Origin

Cellulose has a natural origin and comes mainly from plants. It is naturally synthesised by the process of photosynthesis, in which plants convert carbon dioxide and water into glucose and then polymerise the glucose into cellulose. Cellulose used in processed foods usually comes from wood pulp or cotton fibres.

Characteristics and uses in the food industry

• Insoluble fibre: Improves digestion by increasing volume in the digestive tract.
• Water absorption: Able to absorb water, it increases its volume and promotes bowel movements.
• Stabilizer and thickener: Provides consistency and texture in food products.
• Inertness: Chemically inert, does not react with other food ingredients.
• Low Calorie: Because it is indigestible, it does not contribute any calories to the diet.

Use in ultra‑processed foods

Cellulose is widely used in ultra‑processed foods due to its multifunctional properties:

• Texturizer: Cellulose provides desirable taste and texture in products such as ice cream, sauces and salad dressings. Its ability to form a gel‑like consistency when mixed with water helps create a smooth and creamy texture without increasing fat content.
• Volumizing agent: In low‑calorie and diet foods, cellulose is used to increase the volume of foods without increasing the calorie content, which helps in weight reduction efforts. It is added to baked goods to improve volume and texture while reducing overall caloric density.
• Stabilizer: Helps maintain the stability and uniformity of food products. In beverages and dairy products, cellulose prevents separation and sedimentation, ensuring a consistent texture throughout shelf life.
• Fat replacement: In fat‑reduced products, cellulose can mimic the taste and texture of fats. This is particularly useful in products such as low‑fat ice cream, cheese and dressings.
• Anti‑caking agent: Used in powdered products such as grated cheese and seasoning mixes to prevent clumping and ensure a suitable consistency.
• Emulsifier: Helps mix ingredients that would otherwise separate, such as oil and water, ensuring a homogeneous product.

Effects on human health

Although cellulose is generally considered safe and beneficial as a source of fibre, there are some health aspects and potential side effects:

• Digestion: In moderate amounts, cellulose can promote digestion and prevent constipation. However, excessive intake can lead to digestive problems, including bloating, flatulence and diarrhea.
• Nutrient absorption: High fibre intake can interfere with the absorption of certain minerals such as calcium, iron and zinc, which can lead to deficiencies if not supplemented with a balanced diet.
• Allergies: Although rare, some individuals may have allergic reactions to cellulose or products containing cellulose.
• Distortion of caloric intake: Because cellulose is used in low‑calorie foods, a large proportion of such products in the diet may lead to inadequate nutrient intake.

Sources

1. Mudgil, D., & Barak, S. (2013). Composition, properties and health benefits of indigestible carbohydrate polymers as dietary fiber: A review. International Journal of Biological Macromolecules, 61, 1‑6. doi:10,1016/j.ijbiomac.2013,06.044
2. Pérez, J., Muñoz‑Dorado, J., de la Rubia, T., & Martínez, J. (2002). Biodegradation and biological treatments of cellulose, hemicellulose and lignin: An overview. International Microbiology, 5(2), 53‑63.
3. Slavin, J. L. (2013). fiber and prebiotics: mechanisms and health benefits. Nutrients, 5(4), 1417‑1435. doi:10,3390/nu5041417
4. Food and Agriculture Organization of the United Nations (FAO). (2010). Dietary fibre: Definition, analysis and intake. FAO Food and Nutrition Paper 91. Retrieved from http://www.fao.org/3/a‑i2986e.pdf