Biochemistry

Wheat proteins are involved in the formation of its gluten. Glutenin gives gluten elastic properties, and gliadin causes elongation and coherence. Distinguish between strong and weak gluten. Strong gluten differs from weak gluten in different solvents, a large number of hydrogen and disulfide bonds, lower viscosity. Enzymes contained in the grain do not show their activity until germination. Then they participate in the breakdown and conversion of reserve nutrients. An important role belongs to enzymes in testology. So, proteases inactivate proteins, weaken gluten, and lipoxygenase promotes the release of sulfhydryl groups - SH- protein. Glutathione is involved in this process. It reduces the amount of disulfide bonds and weakens gluten. Therefore, enzyme systems in combination with gluten proteins act as a regulator of the quality of wheat bread. Meat proteins Proteins of muscle tissue are full in composition, easily digested and absorbed by the body. The biological value of meat depends not only on the composition of muscle proteins, but also on the presence of connective tissue and fat. A higher content of the last two components reduces the biological value of meat. Proteins of muscle tissue perform a contractile function, and proteins of connective tissue and cartilage perform a supporting function. Muscle proteins are fibrillar, (filamentous) structure. The protein content in meat products ranges from 11 to 22%. The main muscle proteins are myosin and actin. They participate in muscle contraction and relaxation with the participation of ATP. In addition, myoglobin is found in muscle cells, which accumulates O 2 in the muscles. It is a globular (in the form of a ball) chromoprotein. Under conditions of oxygen starvation, O 2 is cleaved from myoglobin and enters the mitochondria of muscle cells, where ATP synthesis occurs. Iron in myoglobin is 2-valent (oxymyoglobin). The color of meat products depends on myoglobin and oxymyoglobin (bright red). During the oxidation of myoglobin, metmyoglobin (red-brown) is formed. It loses its ability to bind O 2 (iron 3-valence). Thermal effects also lose the ability to bind O 2 . This changes the color of the products (brown). The meat tissue contains collagen. There is a lot of it in cartilage, in the skin, tendons, cartilage, bones, cornea. Collagen has a lot of oxyproline, oxylysine. The amount of collagen digestibility is determined by the amount of oxyproline when evaluating meat quality. 70