At present, the processing methods of fishmeal at home and abroad are mostly processed according to the amount of fish fat, and are divided into two kinds of processing techniques: "high-fat fish" and "low-fat fish".
1 The processing of high-fat fish is the process of degreasing the fishmeal with higher fat content and then drying the flour. First of all, by boiling or dry hot air heating method, the fish tissue protein heat denaturation and coagulation, promote body fat separation and dissolution. The solids are then pressed by a screw press and the solids are dried to make fish meal. Drying methods are classified into dry hot air and steam. The temperature at which the former blows dry hot air varies from 100 to 400°C, depending on the type of heat source; the latter uses steam for indirect heating. Although the drying speed is slow, the quality of the fish meal is good. After the whole fish has gone to oil, soaked in juice, dried and crushed, the protein content varies from 50% to 60%. The squeezed juice is acidified, spray-dried or heated to concentrate fish solubles. The raw material of fish paste can also be used for the internal organs of fish. After enzymatic hydrolysis, centrifugation, degreasing, and then the hydrolyzate is concentrated to form a fish paste. After the preparation, the fish paste can be directly sold in barrels, and starch or bran can also be used. As an adsorbent, it is dried, crushed, and sold. The latter is called a fish juice adsorption feed or a compound fish soluble powder, and its nutritional value varies depending on the carrier.
2 The processing process of low-fat fish is the processing of fish and other seafood with low relative body fat content. According to the type of raw materials, it is generally divided into two categories: whole fish meal and miscellaneous fish meal. The whole fishmeal is made by directly heating and drying the fish with low fat content, losing part of the water, and then degreasing. After the second drying of the fishmeal, the moisture content reaches 18%, and the fish meal is crushed. Usually about 22kg of whole fishmeal can be produced per 100kg of whole fish. Protein content is about 60%. Miscellaneous fishmeal: It is a dry product of small fish, shrimps, crabs and fish heads, tails, fins and internal organs. It is also known as dried fish powder and contains 45% to 55% crude protein. Or in the fish production season, salted raw materials are used first, then desalted, and then dried and crushed. This type of fish meal is often due to incomplete desalination (more than 10% of salt), improper use is likely to cause salt poisoning in livestock and poultry.
Zhengzhou Bridge Biochem Co.,Ltd.
April 01, 2024
