Wheat flour: grades, properties and applications
Wheat flour is a powdered food product obtained by grinding wheat grain. It is one of the most important products of grain processing, forming the basis for the production of bread, bakery, pasta and confectionery products. Wheat flour occupies a dominant position in global milling production, and its quality and grade directly determine the consumer properties of finished products. In modern industry, flour is classified by intended use, chemical composition and technological indicators regulated by state standards.
Chemical Nature and Composition
The basis of wheat flour is carbohydrates, represented mainly by starch, as well as proteins, fats, minerals and dietary fibre. The chemical composition of flour depends on the grade: the higher the grade, the less grain hulls it contains and the lower the content of fibre, minerals and vitamins, but the higher the starch content. According to industry sources, premium grade flour contains about 79% starch, 12% protein, 0.1% fibre and has an ash content of not more than 0.55%. First grade flour contains about 77.5% starch, 14% protein, 0.3% fibre with an ash content of not more than 0.75%. Second grade flour is distinguished by a higher fibre content (about 0.8%) and an ash content of 1.1–1.2%, while wholemeal flour contains up to 16% protein, 2.3% fibre and has an ash content of about 1.9%.
The key technological component of wheat flour is gluten — an elastic protein mass formed by the interaction of the proteins gliadin and glutenin with water. The quantity and quality of gluten determine the baking properties of flour: the ability of the dough to retain gases, form a porous crumb and maintain the shape of the product. That is why the indicator of wet gluten content and its quality (measured by the IDK instrument) is one of the most important in flour assessment.
Classification, Grades and Standards
In Russia and CIS countries, requirements for wheat baking flour are established by GOST 26574-2017 "Wheat baking flour. Specifications", which came into force on January 1, 2019. The standard applies to flour produced from soft wheat or from soft wheat with a durum wheat content of not more than 5%.
According to the standard, wheat baking flour is divided into six grades: extra, premium, krupchatka (semolina), first, second and wholemeal. The division into grades is based on whiteness or ash content, quantity and quality of gluten, falling number, and fineness of grinding.
Extra grade flour is the most finely ground product, practically free of bran, with maximum whiteness. Premium grade flour consists of finely ground particles of the central part of the endosperm, practically free of bran, has a white colour or white with a creamy tint. Ash content is not more than 0.55%, wet gluten content is not less than 28%. Krupchatka is produced from vitreous wheat and has a coarse-grained structure; it is used for yeast dough with a high content of sugar and fat (Easter cakes, sweet pastries). First grade flour is the most common grade for bakery production; it consists of finely ground particles of all endosperm layers, contains 3–4% bran, has a white colour with a yellowish tint, ash content of not more than 0.75%, and a wet gluten yield of about 30%. Second grade flour contains up to 8% bran, has a darker colour and an ash content of 1.1–1.2%; it is used for baking table breads and some confectionery products. Wholemeal flour is obtained by single-grade milling with a yield of 96%; its chemical composition is close to that of the original grain, it has high water-holding capacity and sugar-forming ability, and the wet gluten yield is from 20%.
The new standard includes only graded flour, and requirements for gluten quality and falling number have been tightened: gluten must have from 45 to 90 IDK units (up to 95 for wholemeal), the falling number for premium and first grades must be not lower than 200 s, and for second grade — not less than 180 s.
Production Technology
Wheat flour production is a complex multi-stage process at flour mills. The technological chain includes cleaning grain from impurities, hydrothermal treatment (conditioning), grinding grain on roller mills and sorting the milling products. During graded milling, the grain is sequentially ground, and the resulting intermediate products (groats, dunsts) are sorted using sieves. Various particles of endosperm and hulls are separated, which allows flour of various grades with specified ash content and fineness to be obtained. The separated grain hulls form bran, which is a valuable feed product.
Modern milling complexes are equipped with automated quality control systems, ensuring the stability of finished product characteristics. Finished flour is packaged in paper or polypropylene bags, and is also supplied in bulk in specialised transport.
Applications
Baking industry. This is the main area of wheat flour use. Premium and first grade flour is the basic raw material for the production of wheat bread, loaves, bakery products, as well as for non-sweet baking. Products made from first grade flour stale more slowly, which makes it preferable for mass bread baking.
Confectionery industry. Premium grade flour is used for the production of cakes, pastries, biscuits and other confectionery products where a fine structure and white colour are required. Krupchatka is used for sweet products with a high content of sugar and fat.
Pasta industry. For the production of pasta, special pasta flour from durum wheat or from soft high-vitreous wheat is used. The highest quality pasta is obtained specifically from durum wheat flour.
Other applications. Wheat flour is used in the production of semi-finished products, dumplings, pancakes, as well as a breading and thickener in the food industry. Lower grade flour and bran are used in feed production.
Safety and Storage
Wheat flour is a hygroscopic product prone to moistening and pest development. Storage is carried out in dry, well-ventilated rooms at an ambient temperature not exceeding 25 °C and a relative humidity not exceeding 70%. The moisture content of flour intended for long-term storage or for the regions of the Far North must not exceed 14.5%. When moisture increases, respiration processes are activated, mould fungi develop and mycotoxins accumulate. Pest infestation (granary weevil, mites) must be controlled, and product proximity must be observed, avoiding storage of flour next to strong-smelling products. Flour is a combustible material, and flour dust is explosive, which requires compliance with fire safety measures at milling facilities.
Market and Trends
The global wheat flour market is a large segment of the agro-industrial complex, closely linked to the grain market. According to the International Grains Council, global wheat flour trade has been declining for a second consecutive year in recent seasons: turnover is about 16 million tonnes in wheat equivalent, which is 3% below the previous season. The main reason is the decline in import demand from Iraq and Sudan, which are increasing their own grain processing capacities and reorienting towards wheat imports instead of finished flour. According to IndexBox, in certain periods global flour trade fell to a five-year low of 15.1 million tonnes.
The largest flour exporters remain Turkey, Egypt, Kazakhstan and European countries. The importance of local processing is growing: importing countries are increasingly building their own mills, which reduces demand for finished flour on the global market.
Key industry trends include: growing demand for flour with a high content of dietary fibre and vitamins (lower grade flour, wholegrain), the development of specialised grades for baking and confectionery industries, and the digitalisation of quality control at milling enterprises. Producers with access to quality grain and modern milling capacities occupy stable competitive positions.
Conclusion
Wheat flour remains a fundamental product of the food industry, providing the production of bread and a wide range of food products. Understanding the classification according to GOST 26574-2017, the differences between grades (extra, premium, krupchatka, first, second, wholemeal), key quality indicators (ash content, gluten, falling number, fineness of grinding) and production technologies is the basis for competent selection of flour for specific purposes — from mass bread baking to confectionery and pasta production.