Fundamentals of food technology study manual

part of the fish, which contains the meat along with the bones and skin. For 
example, the mass composition of pollock: head - 21%, meat with skin - 50, bones 
- 8, wings - 3, intestines - 17%. The skin is removed from the fillet and the weight 
of each separated part of the body is determined. Determining the mass 
composition of small fish is often limited to separating the head, tail and intestines. 
Cut the meat with the removed carcass, bones and skin is taken as an edible part of 
fish containing z. For example, the mass composition of pollock: head - 21%, meat 
with skin - 50, bones - 8, wings - 3, intestines - 17%. 
Features of the fish body 
The body of a fish can be considered as a collection of specialized cells, like 
any other animal. Special groups of cells are called tissues. Several tissues 
combine in a certain complex to form an organ. Four groups of tissues are involved 
in the construction of the organs of the fish body: muscle, connective, epithelial 
and nervous. Several organs that perform a certain function together are added to 
the 13 organ system, for example, digestion, support. A complex of interconnected 
organ systems forms an organism. Muscle tissue is the main component of the 
edible part of fish - meat. The basis of muscle tissue is a linear muscle fiber, in 
which the shell - sarcolemma, there is a certain amount of protoplasm - sarcoplasm 
and filamentous formations - myofibrils. In addition to myofibrils, the fiber 
contains a large number of nuclei. In a cod weighing about 4 kg, the width of the 
muscle fiber varies from 0.1 to 0.325 mm, and the length varies from 8.25 to 14 
mm. Myofibrils are located inside the fiber, in which they are arranged in rows 
parallel to the length of the fiber. Under the microscope, along its length, each 
myofibril has a dark line in some places, and a light line in others. In the 
construction of a muscle fiber, the myofibrils are arranged so that the dark areas 
correspond to the dark areas and the light areas to the light areas, giving a cross-
stripe throughout the muscle fiber. There are several types of connective tissue in 
the body of fishes. There are tissues, which are divided into groups according to 
their structure. Cells, fibers and some amorphous substances are involved in the 
construction of any connective tissue; which is in a jelly-like state and lacks cells 
and fibers. There are the following types of connective tissue: with a predominance 
of cells - fat with approximately the same composition of cells and amorphous 
substances - loose connective tissue involved in the construction of muscles; with a 
predominance of fibers - bones, tendons, ligaments, with a predominance of 
amorphous substance - mucous tissues. Fat cells have a membrane, protoplasm and 
nucleus, in which fat accumulates, which are represented by a number of 
microscopic droplets in fat cells. Accumulation of fat cells leads to the formation 
of tissues. According to the location in the fish body, the following fats are 
distinguished: subcutaneous, brown (black) muscles, dorsal, abdominal, 
intramuscular, bone and intramuscular. 4. The structure of the linear muscle fiber 
of fish: a-isolated muscle fiber; Scheme of β-muscle fiber structure: 1-myofibrils; 
2- sarcoplasm; 3rd core; 4 – sarcolemma 

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14 primary organs. Subcutaneous fat is located directly under the skin. Brown 
muscle fat is found on the sides of the fish's body, in the brown muscles along the 
lateral line. Dorsal and ventral fat accumulates under the skin of the back and belly 
of the fish. Intramuscular fat is located deep in the meat, in the connective tissue 
compartments that separate the layers of muscle fibers. Bone fat is located next to 
bone formations, in direct contact with them, mainly along the spine. The fat of the 
internal organs accumulates in adipose tissue and the organs of the internal cavity 
of the fish (liver, brain, genitals) or around these organs, covering them thickly. 
Adipose tissue is unevenly distributed in the same parts of the body in different 
types of fish, it is unevenly distributed in different parts of the body of the same 
type of fish. A cross-section of the body of some fish species shows the 
topographical location of fat. Here, fat is marked in red (stripes, spots, separate 
sections; brown muscles are shaded, fish pieces, internal organs, bones, outer 
contours of muscle bundles are shown with a dotted line. Fat the location of the 
body: a-roach; 6-shepherd; c-cod. Connective tissue fibers are divided into two 
types - collagen and elastin (according to the name of the proteins from which they 
are formed - collagen and elastin, respectively) , they differ from each other. Not 
only in form and structure, but also according to its properties. Fibers are well 
expressed in bone connective tissue, cartilage, and tendons. The presence of 
collagen fibers and elastin fibers in fish muscles has not been proven. Collagen 
fibers are like 15 long strands of varying thickness.