*3.1.2. Effect of the fractional composition of proteins on the functional properties of protein products*

The effect of the fractional composition of proteins on the functional properties of protein products was studied using protein products from wheat bran and their granulometric fractions as an example. Protein products obtained from bran fractions with different particle sizes differed both in their functional properties (**Table 7**) and in the fractional composition of their proteins (**Figure 1**). The highest amount of albumins and globulins (44%) had protein products obtained from the bran fraction with a particle size of 195–670 μm, the lowest (32%) protein products from the fraction with a particle size <195 μm.

The highest amount of gluten proteins (gliadin, glutenin) was observed for products isolated from the fraction with a size of <195 μm, the smallest for products from the cut fraction with a particle size> 1000 μm. A large amount of insoluble glutenin (37%) differed products from a large bran fraction (> 1000 μm), a smaller (12%) from a granulometric fraction with a particle size <195 μm. Mathematical processing of the data showed that protein solubility was directly proportional to the sum of albumins and globulins (r = 0.90), FBA—from the amount of both gluten fractions and their sums (r = 0.78–0.90) and the FEA–of the amount of high molecular weight (MM) glutenin and insoluble proteins (r = 0.73–0.78) (**Figure 1**). A high inverse relationship was found for the solubility of wheat bran concentrate proteins on the amount of gliadin and the average negative correlation (r = −0.51–0.69) for WBA on the amount of gliadin and sum insoluble proteins.

It was found that the functional properties of gluten are also interrelated with the characteristics of the amino acid composition of insoluble glutenin: the more nonpolar amino acids were FEA. The number of polar amino acids is also directly proportional to the FC values but is

*\**PS—protein solubility; WBC—water-binding capacity; FBA—fat-binding ability; FEA—fat-emulsifying ability; SE—

**Protein products PS, % \* WBC, g/g FBA, g/g FEA, % SE, % FC, % FS, %**

0.25

0.50

13.7 ± 0.6 1.1 ± 0.10 2.4 ± 0.09 95 ± 1.2 90 ±

21.5 ± 1.1 1.0 ± 0.09 2.4 ± 0.07 89 ± 1.1 85 ±

26.9 ± 1.6 0.7 ± 0.05 2.8 ± 0.04 72 ± 1.5 79 ±

9.8 ± 0.6 0.5 ± 0.06 4.9 ± 0.07 61 ± 2.0 66 ±

0.08

0.50

0.05

0.08

0.80

0.90

64 ± 1.6 92 ± 2.5

50 ± 2.0 70 ± 1.6

1.2

2.2

1.3

1.4

2.7

49 ± 1.2 47 ± 1.0

61 ± 0.9 48 ± 0.2

55 ± 0.5 55 ± 1.2

48 ± 0.9 45 ± 1.0

57 ± 1.20 54 ± 1.0

87 ± 1.5 88 ± 1.1

220 ± 2.8

182 ± 1.9

132 ± 3.2

130 ± 2.2

129 ± 1.2

107 ± 1.2

110 ± 2.5

200 ± 2.0

100 ± 1.5

65 ± 2.0

59 ± 2.0

75 ± 1.8

74 ± 2.1

65 ± 1.2

63 ± 1.7

57 ± 1.2

65 ± 1.5

40 ± 1.6

80 ± 2.1 60 ± 1.7

50 ± 2.0 68 ± 1.5

95 ± 2.0 55 ± 1.2

85 ± 1.3 70 ± 2.0

DWG (Kazakhstan) 1.2 ± 0.50 2.39 ± 1.00 2.32 ±

DWG (The Netherlands) 1.1 ± 0.15 2.27 ± 0.90 1.24 ±

Soy flour (Belgium) 45.1 ± 2.0 1.60 ± 0.80 1.20 ±

Soy concentrate (Russia) 75.3 ± 1.3 7.40 ± 0.35 2.20 ±

Soy Isolate Supro 760 72.6 ± 1.5 7.90 ± 1.00 1.80 ±

Soy isolate Ardex F 78.5 ± 2.0 6.00 ± 1.50 1.20 ±

Amaranth concentrate 46.0 ± 1.0 2.60 ± 0.05 2.60 ±

Concentrate from rye grains 18.2 ± 1.0 1.80 ± 0.50 2.20 ±

stability of the emulsion; FC—foaming capacity; FS—foam stability.

Concentrates from wheat bran fractions, N of sieve, d, mcm:

Protein products from other types of raw material:

Concentrate from wheat bran 16.0 ± 0.9 2.90 ± 0.08 4.20 ± 0.5 56 ± 1.3 80 ±

inversely proportional to WBC and FBA.

**Table 2.** Functional properties of protein products.

Concentrates from wheat:

212 Global Wheat Production

1.0

067

38

38

> 1000 (descent)

670 (descent)

195 (descent)

<195 (pass)


Note: 1–gluten; 2–gliadin; 3–soluble glutenin; 4–insoluble glutenin.

**Table 4.** Amino acid composition of wheat gluten of different quality and its fractions, g/100 g of protein.
