Characteristics of fish as raw material for industry
Fish as food is one of our main sources of protein. But fish not only give a wide range of foodstuffs, they are also used as a source of valuable medicinal, feeding and technical products. That such full use can be made of fish is explained by the various histological structure and chemical composition of their different parts. The size, chemical composition and food value of fish depend on their species, age, sex, physiological state, and on the conditions in which they live (the hydrology of water and the nourishment they are able to obtain from it).
To be able to use fish properly and process them efficiently it is necessary to know their properties, i. e. their body structure, the size-to-weight ratio of their different parts and organs, their physical properties and chemical composition and the properties of proteins, fat, vitamins, and other substances they contain. Since fish is highly perishable product, it is also important to know the nature and causes of the changes that take place in fish after death.
In addition to the scientific, biological classification of fish into families and species, they are also divided, for practical purposes according to their size (whether large, medium or small); sex (male or female); season of catch; physiological state (whether hunting for food, laying down fat, in pick condition, filling or spent); according to fat content (fatty, medium or lean); according to manner of feeding (whether predatory on other fish or feeding at plankton, benthos or vegetable matter); according to the region where they are found and caught (for example, Caspianbream, Aral bream, Azov bream), and according to the method of capture (trawled, netted or seined). All these classifications help to characterize the food value of fish, in some measure, and to show whether they can be preserved or are suitable for processing into various products.
Exercise 2. Answer the following questions:
1. How may fish be used?
2. How can such full use of fish be explained?
3. What does the size, chemical composition and food value of fish depend on?
4. What is necessary to know to use fish properly and process them efficiently?
5. Why is it important to know the nature and causes of the changes that take place in fish after death?
6. How are fish classified?
7. How are fish classified according to fat content?
8. How are fish classified according to manner of feeding?
9. Why do we need all these classifications?
Exercise 3. Examine the table below thoroughly and find out the information about:
a) assortment of fish products produced in our region;
b) the most popular items;
c) the items increasing in production;
d) the items reducing in production;
e) the possible causes of such dynamics in fish processing;
f) what products would you offer for production.
Table 1. Переработка и консервирование рыбо- и морепродуктов, тонн
| Рыба и продукты рыбные переработанные и консервированные | 506748,8 | 552143,5 |
| Рыба (кроме сельди) мороженая | 429820,9 | 399542,8 |
| Сельдь всех видов обработки | 71930,2 | 51299,3 |
| Филе рыбное мороженое | 20465,4 | 28200,4 |
| Мясо рыбы (включая фарш) мороженое, прочее | 6508,4 | 7844,4 |
| Рыба (кроме сельди) солёная | 1444,1 | 1163,0 |
| Рыба (кроме сельди) копчёная | 477,6 | 463,2 |
| Рыба холодного копчения (кроме сельди) | 376,8 | 365,3 |
| Рыба (кроме сельди) горячего копчения | 100,8 | 97,9 |
| Рыба сушёная и вяленая | 735,8 | 225,5 |
| Рыба сушеная | 503,3 | 9,6 |
| Рыба вяленая | 232,5 | 215,9 |
| Продукты из рыбы (кулинарные изделия) | 2055,7 | 1766,8 |
| Икра | 251,8 | 160,9 |
| Икра лососевая | 1177,7 | 1458,5 |
| Икра прочих рыб | 4,4 | 1,7 |
| Морепродукты пищевые | 1173,3 | 1456,8 |
| Мука тонкого и грубого помола и гранулы из рыбы, ракообразных, моллюсков и других водных беспозвоночных, не пригодные для употребления в пищу | 2584,2 | 2535,4 |
| Консервы рыбные всех видов, туб. | 7642,0 | 6662,6 |
| Пресервы рыбные, туб. | 15493,1 | 8828,5 |