*3.1.3. Effect of the number of thiol exchange groups and the coefficient of the final stage of protein aggregation on the functional properties of protein products*

It is known that the covalent (disulfide) and non-covalent (hydrogen, ionic) bonds and hydrophobic interactions play an important role in the structure of vegetable proteins. To identify the participation of these types of interactions in the formation of the functional properties of products from wheat bran, the content of sulfhydryl groups, disulfide bonds, and the aggregating capacity of proteins were determined (**Figure 2**). It was taken into account that the aggregation of proteins in the presence of sodium chloride molecules is carried out with the participation of hydrophobic interactions. It is established that the values

of FC and FEA protein concentrate are interrelated with the content of -SH-groups and -S-S-bonds: the smaller the -S-S bonds and more -SH-groups, the FC and FEA are higher,

For FBA, the inverse relationship was observed, the more -S-S bonds in proteins, the indicator, on the contrary, was higher (r = 0.755). For solubility and WBC, there was no significant

FEA and SE of protein products from wheat bran were positively correlated with the coefficient of the final stage of aggregation of τ10/C proteins, as well as with the number of -SH-groups. Therefore, one can indirectly conclude that the stronger the property of the surface hydrophobicity of proteins, the ability to emulsify fat and the stability of the emulsion in foods is higher. These results are consistent with the number of non-polar amino acids in gluten and wheat gliad, which included amino acids with hydrophobic radicals

r = 0.896 and 0.732, respectively.

(**Table 6**).

correlation with the indices of thiol metabolism.

**Table 5.** Amino acid composition of protein concentrates, g/100 g of protein.

**Amino acid Protein concentrate from:**

Lysine 5.43 ± 0.50 6.90 ± 0.40 2.55 ± 0.30 Histidine 3.11 ± 0.25 4.86 ± 0.15 1.58 ± 0.09 Arginine 10.57 ± 1.0 6.21 ± 0.60 3.11 ± 0.10 Aspardic acid 9.51 ± 1.0 8.56 ± 0.50 5.43 ± 1.00 Threonine 3.85 ± 0.25 4.62 ± 0.80 2.37 ± 0.55 Serine 5.40 ± 0.50 6.09 ± 0.80 2.49 ± 0.30 Gluetamic acid 17.88 ± 0.90 14.40 ± 1.1 23.78 ± 1.20 Proline 4.64 ± 0.15 3.77 ± 0.55 9.62 ± 1.00 Glycine 5.57 ± 0.50 6.99 ± 0.90 3.51 ± 0.60 Alanine 4.36 ± 0.20 5.92 ± 0.70 4.07 ± 1.10 Valine 5.17 ± 0.20 5.11 ± 0.50 1.47 ± 0.20 Methionine 4.02 ± 0.3 2.84 ± 0.15 2.13 ± 0.25 Cysteine (1/2) 1.25 ± 0.15 5.10 ± 06 5.43 ± 0.32 Isoleucine 4.63 ± 0.9 3.34 ± 0.62 1.82 ± 0.15 Leucine 7.57 ± 1.05 9.35 ± 1.1 5.60 ± 0.35 Tyrosine 4.61 ± 0.10 5.19 ± 1.0 2.32 ± 0.10 Fenylalanine 10.57 ± 1.5 5.83 ± 1.0 3.96 ± 0.06 The sum of polar amino acids 43.39 ± 1.8 36.07 ± 0.89 34.87 ± 1.12 The sum of nonpolar amino acids 46.53 ± 1.3 43.15 ± 0.67 32.18 ± 1.11

**Amaranth Wheat bran Rye grains**

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Interrelation of Functional Properties of Protein Products from Wheat with the Composition…

Interrelation of Functional Properties of Protein Products from Wheat with the Composition… http://dx.doi.org/10.5772/intechopen.75803 215


**Table 5.** Amino acid composition of protein concentrates, g/100 g of protein.

*3.1.3. Effect of the number of thiol exchange groups and the coefficient of the final stage of* 

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

**Amino acid Strong DWG Good DWG Weak DWG**

**1 2 3 4 1 2 3 4 1 2 3 4**

Lysine 2.24 0.70 1.17 2.63 1.57 0.60 1.27 1.74 1.51 0.79 1.21 1.20 Histidine 2.27 1.81 1.47 2.24 1.99 1.70 1.60 1.76 2.04 1.49 1.20 1.67 Arginine 3.62 2.87 2.85 3.96 3.76 2.55 3.62 4.24 3.43 2.51 3.10 3.44 Aspardic acid 3.75 2.84 2.69 4.09 3.17 3.12 2.62 3.89 3.32 2.95 1.99 4.44 Threonine 2.37 2.20 2.73 5.13 5.16 2.24 2.58 3.95 2.55 2.49 2.96 4.40 Serine 4.87 4.12 3.33 4.25 3.05 4.64 4.61 5.23 4.93 3.97 6.08 8.12 Gluetamic acid 40.16 50.86 49.56 33.15 43.59 50.53 44.36 31.88 43.66 50.96 42.06 30.47 Proline 18.19 18.09 17.40 12.08 17.16 20.95 15.44 10.73 19.12 18.73 14.62 8.47 Glycine 3.96 1.89 3.43 5.32 3.66 1.69 3.51 4.37 4.16 1.63 3.55 5.90 Alanine 3.34 2.50 2.53 2.71 3.34 2.27 2.05 2.90 2.89 2.25 1.97 3.19 Valine 4.58 5.15 4.53 3.96 5.08 5.11 3.69 4.56 4.52 4.74 3.58 3.79 Methionine 2.13 1.64 1.78 1.79 1.73 1.48 1.21 1.33 1.91 0.95 1.21 1.59 Cysteine (1/2) 5.43 5.10 5.74 5.10 3.25 2.72 3.91 2.81 1.91 2.84 4.23 2.60 Isoleucine 4.80 5.10 3.65 2.95 4.49 4.84 3.42 3.33 4.42 4.42 3.32 3.26 Leucine 7.84 8.44 7.34 6.82 8.08 7.83 6.34 7.33 7.99 7.15 5.92 6.37 Tyrosine 3.88 3.01 3.53 3.90 3.65 2.87 3.55 3.45 3.48 2.88 3.48 4.62 Fenylalanine 6.76 6.61 5.97 4.06 7.48 7.07 5.25 5.49 7.05 6.68 5.20 2.83

It is known that the covalent (disulfide) and non-covalent (hydrogen, ionic) bonds and hydrophobic interactions play an important role in the structure of vegetable proteins. To identify the participation of these types of interactions in the formation of the functional properties of products from wheat bran, the content of sulfhydryl groups, disulfide bonds, and the aggregating capacity of proteins were determined (**Figure 2**). It was taken into account that the aggregation of proteins in the presence of sodium chloride molecules is carried out with the participation of hydrophobic interactions. It is established that the values

49.77 57.27 56.27 43.83 52.09 56.80 50.60 41.75 51.92 57.21 44.05 39.55

52.20 49.42 46.63 39.69 51.02 51.27 40.91 40.04 52.06 46.55 39.93 35.4

*protein aggregation on the functional properties of protein products*

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

The sum of polar amino acids

214 Global Wheat Production

The sum of nonpolar amino

acids

of FC and FEA protein concentrate are interrelated with the content of -SH-groups and -S-S-bonds: the smaller the -S-S bonds and more -SH-groups, the FC and FEA are higher, r = 0.896 and 0.732, respectively.

For FBA, the inverse relationship was observed, the more -S-S bonds in proteins, the indicator, on the contrary, was higher (r = 0.755). For solubility and WBC, there was no significant correlation with the indices of thiol metabolism.

FEA and SE of protein products from wheat bran were positively correlated with the coefficient of the final stage of aggregation of τ10/C proteins, as well as with the number of -SH-groups. Therefore, one can indirectly conclude that the stronger the property of the surface hydrophobicity of proteins, the ability to emulsify fat and the stability of the emulsion in foods is higher. These results are consistent with the number of non-polar amino acids in gluten and wheat gliad, which included amino acids with hydrophobic radicals (**Table 6**).


with increased FC and solubility [30]. In multi-stranded polypeptides, DWG, there were more single-chain peptides with low MW (12–16 kDa) and fewer with medium (27–39 kDa) and

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**Figure 1.** Coefficients of pair correlation between functional properties products and fractional composition of proteins.

**Figure 2.** Coefficients of pair correlation between the content of thiol metabolism, protein aggregation coefficient, and

high (69–108 kDa) MM.

functional properties of products.

**Table 6.** Coefficients of correlation between functional properties protein products and the sum of amino acids.


**Table 7.** Functional properties of protein preparations.

The functional properties of DWG depend on the molecular weight (MM) of the individual electrophoretic components obtained in PAGE. Using the example of native and modified DWG obtained by the limited proteolysis method, we showed that single-chain polypeptides with low (<40 kDa) and medium (40-60 kDa) MM were included in the composition of DWG with increased FC and solubility [30]. In multi-stranded polypeptides, DWG, there were more single-chain peptides with low MW (12–16 kDa) and fewer with medium (27–39 kDa) and high (69–108 kDa) MM.

**Figure 1.** Coefficients of pair correlation between functional properties products and fractional composition of proteins.

**Figure 2.** Coefficients of pair correlation between the content of thiol metabolism, protein aggregation coefficient, and functional properties of products.

The functional properties of DWG depend on the molecular weight (MM) of the individual electrophoretic components obtained in PAGE. Using the example of native and modified DWG obtained by the limited proteolysis method, we showed that single-chain polypeptides with low (<40 kDa) and medium (40-60 kDa) MM were included in the composition of DWG

**Table 7.** Functional properties of protein preparations.

**The sum of amino acids Functional properties**

Wheat gluten

Gliadin

Soluble glutenin

Insoluble glutenin

Polar −0. 96 0.54 0.95 −0.78 −0.66 0.22 Nonpolar 0.98 −0.36 −0.76 0.86 −0.11 −0.36

Polar −0.97 −−0.20 0.78 −0. 84 0.21 0.21 Nonpolar −0.21 −0.42 −0.30 0.70 0.79 0.99

Polar 0.62 −0.67 −0.85 −0.62 −0.67 0.54 Nonpolar 0.88 0.62 −0.92 −0.39 0.80 0.14

Polar 0.24 −0.98 −0.86 −0.61 0.97 −0.49 Nonpolar 0.10 0.57 −0.52 −0.74 0.95 0.90

Polar 0.15 0.54 −0.17 −0.37 0.93 0.44 Nonpolar 0.06 0.65 0.10 −0.79 0.68 0.85

Wheat gluten and its fractions:

216 Global Wheat Production

Protein concentrates from wheat bran

**Raw material PS, % FEA, % SE, % FBA, g/g FC, %** Total insoluble fibers 16.0 ± 0.3 89 87 3.6 119 > 1000 13.7 ± 0.2 95 90 2.4 132 670–1000 21.5 ± 0.3 89 85 2.4 130 195–670 26.9 ± 0.5 72 79 2.8 129 < 195 9.30 ± 0.1 61 66 4.9 107

**Table 6.** Coefficients of correlation between functional properties protein products and the sum of amino acids.

**PS, % WBC, g/g FBA, g/g FEA, % FC, % FS, %**

The revealed regularities of interrelation of functional properties with the component composition were intended for the use of DWG in the production of confectionery products.

**Conflict of interest**

**Abbreviations**

The authors declare no conflict of interest.

DWG dry wheat gluten PS protein solubility FBA fat-binding ability FC foaming capacity

WBC water-binding capacity ST stability of emulsion

Valentina V. Kolpakova\*, Nikolay D. Lukin and Irina S. Gaivoronskaya

All-Russian Scientific Research Institute of Starch Products–A Branch of the V.M. Gorbatov Federal Research Center for Food Systems of Russian Academy of Sciences, Kraskovo,

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[2] Kolpakova VV, Volkova AE, Nechaev AP. Protein from wheat bran. Functional properties of protein flour: Emulsifying and foaming properties. Izvestiya Vuzov. Food

[3] Kolpakova VV, Nechaev AP. Protein from wheat bran. Functional properties of protein flour: Solubility and water binding ability. Izvestiya Vuzov. Food Technology.

[1] Tolstoguzov VB. New Forms of Protein Food. М: Agropromizdat. 1987;303

\*Address all correspondence to: val-kolpakova@rambler.ru

FS foam stability –S-S– disulfide bonds –SH sulfhydryl groups MM molecular masses

**Author details**

Russia

**References**

Technology. 1995;**1-2**:34-37

1995;**1-2**:31-33
