**2.4. Determination of the fractional composition of proteins**

bran and their fractions obtained according to the technology developed by us [27]. To study the amino acid composition of proteins, three samples of wheat gluten were used, which were manually washed from the flour of a typical "strong" sort of grain Saratov 29 (spring), typically "weak"—Akmolinka 1 (spring) and typically medium Gorkovskaya 52 (winter). The crude gluten was dried on a lyophilic plant, it was regenerated by washing in tap water for 15 min and the deformation index on the IDG-1 instrument was determined. Regenerated gluten in the first grade of grain was characterized as slightly elongated, "strong," with an indicator of the device of 58 units, in the second—tensile, "normal" with an indicator of 70 equipment units, the third—as very extensible and "weak" with an indicator of 100 equip-

Protein concentrates from wheat bran were obtained from various systems of the technological process of JSC "Moscow Combine of Bread Products," the quality of grain and bran was in accordance with the requirements of standards. The bran was combined, sieved through a sieve of different diameters, and granulometric fractions with a particle size of more than

To compare the results of the relationship between functional properties and physicochemical parameters for proteins from wheat and protein products from another type of raw material, soy concentrate, soy isolate Supro 760 from "Soloe" Supro (USA), soy isolate ArdexF ADM (USA), concentrates from amaranth and grain of rye, obtained by our methods [28, 29].

Indicators of the chemical composition of protein products were determined by the methods of state standards of the Russian Federation and generally accepted methods. The mass fraction of moisture was determined in accordance with GOST 13586.5-85; ash content—GOST 10847-74; mass fraction of fat—according to the method of Soxhlet in the apparatus of the firm "Buchi"—GOST 29033-91, the mass fraction of protein—in the automated Kjeldahl system of the firm "Buchi"—GOST 10846-91, fiber—according to Gennesberg and Shtoman—GOST 31675-2012. Carbohydrates were calculated as the difference between 100% and the sum of

A liquid chromatograph from Hitachi (Japan) was used in a mode with a sulfonated styrene-divinylbenzene copolymer and a step gradient of sodium citrate buffer solutions with increasing pH and molarity. The data were processed in an online system "MultiChrome 1.52" for Windows 98. A sample of 3–5 mg sample was placed in a glass ampoule, 300 μl of a mixture of concentrated hydrochloric acid and trifluoroacetic acid (2, 1) with 0.1% 2-mercaptoethanol was added. The sample was frozen in liquid nitrogen, evacuated and hydrolyzed at 155°C for 1 h. The hydrolyzable mixture was evaporated on a rotary evaporator (Centrivap Concentrator Labconco, USA). To the residue, 0.1N HCl was added and centrifuged for 5 min

1000, 670, 195, and less than 195 μm were obtained.

**2.2. Determination of chemical composition**

the mass fraction of protein, fat, ash, and fiber.

**2.3. Determination of the amino acid composition of proteins**

at 800 g on a Microfuge 22R centrifuge (Beckman-Coulter, USA).

ment units.

208 Global Wheat Production

1 g of the protein product, weighed to within 0.001 g, was placed in a centrifuge tube, 10 cm3 of a 0.5 mol/dm3 NaCl solution was added, shaken for 1 h and centrifuged for 15 min at 8000 g. The centrifugate was drained, 10 cm3 of cold distilled water was added to the precipitates, thoroughly mixed, and centrifuged again. The combined centrifuges were taken as albumins and globulins. To extract the gliadin proteins, 20 cm3 of 70% ethanol was added to the precipitates, shaken at 180–200 rpm for 1 h and left overnight at room temperature. The next day the sample was shaken for 30 min and centrifuged at 8000 g for 15 min. The centrifugate (gliadin) was drained, 20 cm3 of 0.1 mol/dm3 acetic acid was added to the precipitates and again shaken for 1 h. The suspension was centrifuged under the same conditions. The extraction procedure was repeated one more time. The combined solutions of proteins soluble in acetic acid were considered to be soluble glutenin. To isolate insoluble glutenin to the precipitates, 20 cm3 of AUC included 0.1 N acidic acid, 6M urea, and cetyl three methyl ammonium bromide solvent (pH 4.1) were added [24]; the tubes were shaken for 1 h and centrifuged. The extraction operation was repeated once more, after which the centrifuges were combined and the protein content of Kjeldahl was determined therein. The protein precipitate was designated as an insoluble protein. The amount of each fraction was expressed as the percentage of soluble and insoluble protein from the total amount of protein in the sample.
