Wheat gluten: properties, grades and applications

Wheat gluten is a concentrated protein obtained during the complex processing of wheat grain, primarily as a by-product of wheat starch production. It is a powder ranging from cream to yellow or light brown in colour, with no foreign odour. Due to its unique ability to form an elastic and extensible protein network when mixed with water, gluten is an indispensable ingredient in the baking industry and is finding increasingly wide application in the production of meat products, feed and technical materials.

Chemical Nature and Composition

The basis of wheat gluten is the storage proteins of the wheat endosperm — gliadin and glutenin. When interacting with water, they form a three-dimensional viscoelastic network capable of retaining gases, which provides the unique baking properties of wheat flour. According to standard requirements, the mass fraction of protein calculated on a dry basis for grade A gluten must be at least 70%, and for grade B — at least 60%. In a quality product, the protein content typically reaches 75–80%. Moisture content (not more than 10%), ash content (not more than 2% for grade A) and fineness of grinding (particles larger than 200 μm — not more than 1% for grade A) are also standardized. The nutritional value of 100 g of the product is about 350–370 kcal, with protein content reaching 75–76 g, fat — less than 2 g, and carbohydrates — about 9–14 g.

Classification, Grades and Standards

In Russia and CIS countries, requirements for wheat gluten are established by GOST 31934-2012 "Wheat gluten. Specifications". The standard applies to gluten obtained during the complex processing of wheat grain and intended for the food industry, public catering and feed production. Depending on physicochemical indicators, gluten is divided into two grades: grade A — with stricter requirements for ash content and fineness of grinding, and grade B — with tolerances oriented towards feed and technical purposes.

By functional state, vital (native) gluten, which retains the ability to form an elastic network after rehydration, and devitalized (modified) gluten, which has lost this ability as a result of heat or chemical treatment, are distinguished. Vital gluten is the main commercial product for baking.

Production Technology

Industrial gluten production is based on the separation of wheat flour into starch and protein. There are two main approaches: the "dough" process (kneading dough and subsequently washing out starch with water) and the "batter" process (mixing flour with water in certain proportions to obtain a fluid suspension, followed by separation by centrifugation or hydrocycloning). After starch separation, the wet gluten is dewatered and dried at controlled temperatures to preserve the native protein structure (for vital gluten). The finished product is ground to a powder and packaged. Modern technologies allow high yields and stable product quality to be achieved.

Applications

Baking industry. Vital wheat gluten is used to strengthen "weak" flour, increase the water absorption capacity of dough, improve bread volume and crumb structure, and stabilize quality when processing flour with inconsistent properties. It allows manufacturers to maintain the traditional characteristics of the product while using cheaper or lower-quality grain.

Meat product production. Hydrated gluten is used as a binder, filler and moisture-retaining agent in sausages, frankfurters and chopped semi-finished products, improving the yield of finished products and the stability of the emulsion. It is also used to create the texture of plant-based meat analogues.

Pasta and confectionery industry. Gluten is added to pasta dough to increase strength and reduce cooking losses, as well as to formulations of certain types of biscuits and sweet pastries.

Feed production. Gluten (including grade B) is used in the production of compound feeds for domestic and farm animals as a high-protein component.

Technical and industrial applications. Due to its film-forming, adhesive and thermosetting properties, gluten is being researched and used to create biodegradable films, adhesives, plastics and coatings. It is considered a renewable and biodegradable raw material for sustainable chemistry.

Safety and Storage

Wheat gluten is a food product, but it poses a risk to people suffering from celiac disease or gluten intolerance. Therefore, the product must be accompanied by appropriate labelling. Storage is carried out in dry, well-ventilated rooms at a relative humidity of not more than 75%, in hermetic packaging that protects against moisture and contamination. At high humidity, gluten can cake and lose its functional properties. The product is a combustible material; gluten dust is explosive, which requires compliance with fire safety measures at production facilities.

Market and Trends

The global wheat gluten market demonstrates steady growth, driven by demand for plant proteins, the development of the bakery market and the growth in production of plant-based meat analogues. According to industry sources, the market size in recent years has been estimated in the range from 2.5 to 11 billion US dollars depending on the methodology, with a projected compound annual growth rate of 3% to 11%. The largest production capacities are concentrated in countries with developed wheat processing — in Europe, North America and Asia. In Russia, wheat gluten production in recent years is estimated at 55–60 thousand tonnes, while the market is characterized by high concentration: several large enterprises control a significant share of output. The key growth drivers remain demand for high-protein ingredients and the development of deep grain processing.

Conclusion

Wheat gluten remains a unique and multifunctional product of grain processing. Understanding its chemical nature, grade composition according to GOST 31934-2012, the differences between vital and devitalized states, as well as production technologies and applications, is the basis for competent selection of the product for specific tasks — from strengthening flour in baking to creating the texture of plant-based products and biodegradable materials.