BIOCHEMICAL MECHANISM OF AUTOLYTIC PROCESSES OF MUSCULAR TISSUE OF FISHES

The conducted researches allowed to establish that intensive disintegration of a muscular glycogen leads to sharp decrease in size рН muscular tissue in the sour party that in turn affects a chemical composition and physic-colloidal structure of proteins therefore: resistance of meat of fish to action of putrefactive microorganisms increases; solubility of muscle proteins, level of their hydration which is water connecting abilities decreases; there is a swelling of collagen of connecting fabric; activity of the cathepsin (an optimum рН 5,3) causing hydrolysis of proteins at later stages of an autolysis increases; the bicarbonate system of muscular tissue with release of carbon dioxide collapses; predecessors of taste and aroma of meat are formed; process of oxidation of lipids becomes more active. As a result of accumulation dairy, phosphoric and other acids in meat of fish concentration of hydrogen ions of that decrease рН is result increases. Sharply shown sour environment and availability of inorganic phosphorus is considered the reason of disintegration of an actin-myosin complex on actin and a myosin which begins after 8 hours of storage, i.e. there comes the period of relaxation of muscle fibers and the period of permission of an numbness, and then the last stage of maturing of meat – deep autolysis. Thus, on the basis of classical ideas of biochemical changes of meat of land animals and summarizing the obtained data on posthumous changes in muscular tissue of fishes, it is possible to draw a conclusion that they have similar nature of regularity in comparison with muscular tissue of land animals, but their main difference is higher speed of course of autolytic transformations. It in turn leads to faster change of FTS of meat of fishes who are the defining indicators when developing assortment groups of products taking into account stages of an autolysis in meat

Investigation of Seiche Oscillations in a Free Entrance Bay

Seiche oscillations in a free entrance bay are investigated within the framework of the linear theory of long waves in two-dimensional formulation. Analytical solution for a rectangular basin of constant depth for the case when the nodal line of the level is located at the basin entrance is obtained. It is shown that allowance for two-dimensional spatial character is important for transverse seiches: the wave currents depend on two spatial coordinates, and their amplitudes are the functions of the basin width and length. The amplitudes of wave current velocities are the functions of the basin width and length for transversal seiches and are directly proportional to the initial level deviations as well as inversely proportional to square root of the basin depth. It is found that for the longitudinal seiches the wave current velocities are normal to the bay entrance and their maximum values do not depend on its width and length. The longitudinal seiches are characterized by the highest velocities of the wave currents. The features of the seiches in a free entrance basin and in a completely enclosed one are compared, their similarities and differences are determined. The lowest seiche mode in the basin with a free entrance is the Helmholtz mode. It is absent in an enclosed basin and also this mode has no nodal lines within the bay. Wave current for the Helmholtz mode is always directed perpendicularly to the basin entrance and its maximum velocity does not depend on the basin width and length. It is directly proportional to free surface initial deviation and inversely proportional to square root of the basin depth. The lowest current velocities will take place at an open boundary of the basin. The estimates for seiche oscillation periods and wave current velocities approximating the Kruglaya Bay in Sevastopol are obtained