The content of protein substances in grain and, accordingly, in flour and pasta, their composition, condition and properties are of primary importance. When storing wheat and other types of grain products, as well as pasta, the properties of proteins change, which leads to a decrease in hydrophilicity and compliance with their proteolytic enzymes. The increased temperature and relative humidity of the air in warehouses activate undesirable processes that occur in pasta during storage. The study of the protein complex during storage is relevant.
Proteins are high molecular weight substances built from various amino acids and linked by peptide bonds. The amino acid composition of bread products, including pasta, determines their nutritional value. Wheat contains simple proteins that consist of amino acid residues and complex proteins that consist of proteins with inclusions of metal ions, pigments, complexes with lipids, nucleic acids, as well as covalently bound phosphoric or nucleic acid residues [1-3].
Essential amino acids such as isoleucine, leucine, lysine, methionine, phenylalanine, tryptophan, threonine and valine are of particular value because they cannot be synthesized in the human body. The content of protein in pasta products depends on the quality of the used raw material. In the grits obtained from hard and high-glass soft wheat, proteins are mainly in an attached form in the form of films 1–2 µm thick, sticking together and flowing around the starch grains into separate granules. In flour obtained from soft and powdery wheat, proteins are arranged in the form of particles and lumps of 2-3 microns in size separately or next to starch grains (Fig. 1-3).
Durum wheat has a glassy consistency, rich yellow-amber colour, protein content - 13-15%, the main purpose - production of grains. Soft, strong and valuable wheat has a glassy and semi-glassy consistency, protein content - 11-13%. It is used for the production of grains and flour for baking. Soft weak wheat has a white colour on the cut, a mealy consistency, protein content - 9-11%. It is used for the production of flour for confectionery and flour products. An increase in the percentage of protein in pasta enhances the elastic properties of products, reduces the dry matter content in the cooking water, reduces the degree of adhesion of cooked products.