Introduction:
Tilapia is the best-selling freshwater fish in the world and is loved by consumers for its delicious meat. Do you also want to start your tilapia processing business? But before starting your tilapia processing business, you may want to know very much about tilapia processing. To save you time, I have written this guide. This guide will give you detailed information about the tilapia processing steps and the machines used to process tilapia. After reading this guide, you will have a complete understanding of the tilapia processing steps.
Let’s get start.
Receiving the tilapia
The first principle of raw tilapia: The tilapia should be clean, unpolluted, and live.
The quality of raw fish acquired by the enterprise should meet the standards of the industry. For each batch of raw fish, it must go through sampling inspection by quality inspection personnel, and raw fish that do not meet the quality regulations should be rejected.
Tilapia should be put into the temporary holding tank as soon as possible after unloading. In the temporary holding tank, the ratio of fish and water is 1:3, and the water level of the temporary holding tank should be adjusted in time after the fish is put in. Tilapia should be temporarily kept in the temporary holding tank for more than 2 h before processing. During this process, the temporary holding tank should be continuously oxygenated and sprayed with a circulating water pump.
The water temperature of the transient pond should be controlled below 22 ℃, and cooling measures should be taken when the temperature is too high.The small-sized fish that are not suitable for processing and the fish that have died are sorted out, and the qualified tilapia are put into the conveyor belt and sent to the bleeding process.
Bleeding, Cleaning, and Disinfection
When bleeding, press the fish head firmly with the left hand on the operating table, hold the sharp knife with the right hand, insert the knife diagonally from both sides of the gills to the heart of the fish, then put the fish into the bleeding tank. The time of bleeding should be controlled for 20-40 min.
After bleeding, the fish were rinsed with water and then disinfected with ozonated water (ozone concentration higher than 0.5 mg/L) for 5-10 min, and the water temperature should be controlled below 15 ℃.
Filleting
Tilapia filleting has two ways in the world. One is filleting by hand, and the other is using the fish filleting machine. As filleting by machine has a high waste rate, so in most of the tilapia plants in the world are still filleting by hand.
Manual filleting：Place the fish on the counter, hold the fish with one hand, and with the other hand, cut the fish with a knife at the end of the fish close to the backbone and horizontally towards the head to the gills, cut off the fillet on the fish, and then cut off the other side of the fillet in the same way. Make sure you cut accurately to avoid shredding.
Filleting by machine:Although the waste rate of machine filleting is high, in some tilapia processing plants,especially in developed countries,they also choose to use machines to fillet the tilapia due to the high cost of labor.Filleting by machine need two main machines:fish head cutting machine and fish filleting machine.First, put the tilapia on the conveyor of fish head cutting machine, the machine will cut the head of tilapia automatically, after removing the head, the body of tilapia will be send to the filleting machine, one operator will put the fish body in the filleting machine, then the backbone will be removed and get two pieces of tilapia fillets.
Skinning and cleaning
After getting the fillets, operators will put the fillets on the conveyor of the automatic fish skinning machine, the skinning machine will remove the skin of tilapia and send the fillet(without skin) to the cleaning tank, the blood stains on the fish fillets will be cleaned here.
Trimming and Checking
After the skinning process, there are still some tiny pinbone in the fillet, which need to be removed manually in this step.Also some other residual parts of the fish fillets are removed in this process.
After finish trimming, workers will check whether there are still fish bones left manually. Some advanced processing plants also use a light inspection table for light inspection, where the fish fillets are placed on the light inspection table for light inspection to pick out parasites, and the light level should be 1,500 Lx or more. Illumination is commonly known as lux (Lx), indicating the amount of luminous flux per unit area of the subject.
Grading
Before packing, the fillets need to be graded according to their weight, and the unqualified ones are removed.
After the grading process, before the disinfection and sterilization process, companies can determine whether to rinse according to customer requirements, that is, with a solution containing polyphosphate and other food additives for immersion rinsing. The temperature of liquid rinsing should be controlled at about 5 ℃, more than 5 ℃ need to add ice to lower the temperature, rinsing time should not exceed 10 min.
Disinfection and Sterilization
Use ozone water (ozone concentration higher than 0.5 mg/L) to sterilize fish fillets for 5-10 min, and the temperature of ozone water should be controlled below 5 ℃.
Quick freezing
IQF quick-freezing technology is used to freeze the tilapia fillets rapidly. This process generally uses a tunnel type individually quick-frozenquick freezer. When freezing, the tilapia fillets should be evenly and neatly placed on the freezing conveyor belt and should not be too dense or overlapped.
The temperature of the freezing tunnel should be lowered to below -35 ℃ before putting in the fish fillets, the freezing process should be below -35 ℃ in the freezing room, the freezing time should be controlled within 50 min, and the final freezing temperature in the center of the product should be below -18 ℃.
Ice glazing
The water used for ice glazing should be pre-cooled to below 4 ℃ and made into ice water for spare. Put the frozen tilapia fillet into ice water or spray with ice water for 3~5 s, so that the surface is covered with transparent ice coating.
Benefits of Ice glazing:
Freshness preservation: Ice glazing can effectively reduce the surface temperature of fish and shrimp, slowing down the growth of bacteria and microorganisms and extending the freshness period of the food. The cooling effect created by the ice coat prevents premature spoilage and maintains the freshness of the food.
Protection: The ice coat provides some protection to the surface of fish and shrimp from external environmental influences such as oxidation, contamination and odors. It creates a physical barrier that reduces contact with air and other substances, helping to maintain the quality of the food.
Vacuum packaging and metal detection
In order to better protect the fish fillets, it is necessary to put the fish fillets into plastic bags for vacuum packaging, using vacuum packaging machine can completely evacuate the air inside the plastic bags. According to customer’s demand, we can also use carton for external packaging.
After all the packaging is completed, before being put into the warehouse, the package needs to go through a metal detector to detect whether the package contains metal, and if metal is detected (such as metal pieces with a diameter greater than 0.5 mm), it should be picked out and handled separately. The outer packaging marking of exported products should meet the relevant requirements of importing countries and regions.
Storage in the warehouse
After the products are inspected and qualified, they are quickly sent into the cold storage for freezing, and the temperature of the cold storage should be controlled at -18 ℃ or below. Cold storage temperature fluctuations should be controlled within 3 ℃.
Conclusion
These processes are applicable to all tilapia processing plants around the world today. Some of the processes can be modified according to customer’s specific requirements. If you have any questions about tilapia processing, please feel free to contact us. We are a professional tilapia processing equipment solution provider, and we can also customize for you.
