CN101919539A - Processing method of sushi fish fillet - Google Patents

Abstract

The invention relates to a processing method for sushi fish fillets, belonging to the field of aquatic product processing. The present invention uses live and fresh fish with scales as raw materials, through inspection, temporary storage in ice water, pretreatment, or frozen fish with scales as raw materials, ultrasonically thaws first, and then removes tails, scales, ultrasonic cleaning, sectioning, and trimming. , Picking insects, removing thorns, cleaning, ultrasonic quick freezing, grading, ice coating, packaging, metal detection, frozen storage and other processes to process sushi fish fillets. The sushi fish fillets processed by this method are of good quality, and the sensory, physical and chemical properties, safety and sanitation quality all meet the requirements, and the thawing and freezing time is short, and the processing efficiency is high, so it can be popularized and applied in the field of aquatic product processing.

Description

Processing method of sushi fish fillet

technical field

The invention relates to a processing method of aquatic products, in particular to a processing method of sushi fish fillets. The invention belongs to the technical field of aquatic product processing. The sushi fish fillets processed by the method are of good quality, and the sensory, physical and chemical, safety and sanitation qualities all meet the requirements, and the thawing and freezing time is short, and the processing efficiency is high.

Background technique

Sushi is rice mixed with seasonings such as vinegar and salt, kneaded into rice balls, added fish slices, shrimp slices, wasabi or pickled cucumbers, egg skins, etc., and then wrapped with seaweed. There are two types of sushi: meat and vegetables. The meat type is mainly various aquatic products, such as red sea bream fillets, salmon fillets, tilapia fillets, etc. The vegetable type is mainly egg skin, pickled melon and cucumber. Fish fillets are an important raw material for sushi. However, the sushi fillet muscle generally has high water content, fragile tissue, less natural immune substances, easy oxidation of unsaturated fatty acids, high soluble protein content, easy corruption, and difficult storage.

The raw material for sushi fillet processing can be frozen fish or fresh fish. Before the frozen fish is processed into sushi fillets, it must be thawed first. There are many ways to thaw, and the commonly used ones are: air and water are thawed by convective heat exchange and contact with the hot surface, electric thawing, vacuum or pressurized thawing, and a combination of the above methods. Air thawing is a thawing method using air as the heat transfer medium, and it is mostly used for thawing livestock carcasses. Water thawing is a thawing method in which water is used as a heat transfer medium. Its thawing speed is faster than air thawing, and there is no weight loss. However, there are problems in this method: loss of soluble substances in the fish body; expansion of the fish body after absorbing water; microbial contamination in thawed water, etc. Vacuum thawing uses the latent heat released by the condensation of water vapor in the vacuum chamber on the surface of the frozen fish body. Its disadvantages are that the thawed food has a poor appearance and high cost. Electrothawing includes far-infrared radiation thawing, high-voltage electrostatic thawing and electrothawing at different frequencies. Among them, the far-infrared radiation thawing technology has been used in the thawing of meat products, and its radiation penetration depth depends on the structure and properties of the fish body, generally up to 0.1mm to 2mm. There is a big problem with this method: when the central temperature reaches the phase transition, the surface temperature of the food rises too much, and the stay time at high temperature (20°C) is too long, which makes the food susceptible to deterioration or even loss due to the action of microorganisms. water, ripening. Therefore, low-temperature far-infrared radiation heaters should be selected as the heat source in application and production, and the food surface should be protected by low-temperature media, such as using low-temperature air to circulate on the food surface. The low-frequency thawing technology requires that the surface of the food is flat and the internal components are uniform, otherwise poor contact or local overheating will occur. The disadvantage of microwave thawing is that it is not suitable for complete thawing. This is because the water molecules in the food material can absorb microwave energy in a large amount only after thawing; and the water molecules in the crystal have low microwave absorption ability. When microwave thawing, if the ice somewhere on the surface of the frozen product melts into water, the temperature at that place will rise rapidly, and even the surface of the frozen product will be partially scorched after it is completely thawed. In addition, someone studies the thawing process that heat pipe technology is used for food. This method is to insert a certain length of heat pipe into the center of the frozen product, and use the high thermal conductivity of the heat pipe to accelerate the temperature rise rate of the thermal center of the frozen product. Its disadvantage is that the appearance of the food after thawing is not good due to drilling holes, and it is only suitable for large pieces of frozen meat.

A critical step after thawing carcasses or fillets of fresh fish is freezing. Common freezing methods include air freezing method, blast freezing method, contact freezing method, dipping freezing method, liquefied gas freezing method, etc. The air freezing method is to use still air as the freezing medium of food. In the freezing room of -18 ℃ ~ -40 ℃ insulated, the fish body is directly placed on the cooling pipe rack that absorbs the latent heat of refrigerant evaporation or put into the freezing plate. The method of freezing inside and then on the drain tube. The freezing speed of this method is slow, and it takes 20h to 40h to freeze. Compared with other methods, the quality of frozen products is poor, but the drying consumption is less. The blast freezing method is a method of forcing the cold air of -35°C to -40°C to flow and circulate at a speed of 3m/s to 5m/s in the freezing chamber to achieve the purpose of rapid freezing. This method does not shorten the freezing time much, but excessive dry consumption is caused by the accelerated drying of fish body moisture due to excessive wind speed. The contact freezing method, also known as the plate freezing method, is a freezing method in which the fish body is directly in contact with a low-temperature metal device, and the freezing speed of this method is relatively low. The immersion freezing method, also known as the immersion freezing method, is to pack the fish fillets in a sealed container and then immerse them in a low-temperature liquid medium for freezing. The liquefied gas freezing method, also known as the ultra-low temperature refrigerant freezing method, is a method in which liquid nitrogen (boiling point -195.8°C) and liquid carbon dioxide (boiling point -79°C) refrigerants are directly sprayed on fish fillets to freeze them rapidly. This method has fast freezing speed and simple operation, which is 5-6 times faster than the plate freezing method. There is no dry consumption of fish body freezing, and oxidation changes are not easy to occur, but due to the large temperature difference, it is easy to cause cracks in the fish body.

So far, there are no patents and other literature reports identical with the present invention.

Contents of the invention

The purpose of the present invention is to provide a safe and efficient method for processing sushi fillets. The invention relates to a processing method for sushi fish fillets, belongs to the field of aquatic product processing and can be popularized and applied in the field of aquatic products.

The benefits and advantages of this method over traditional methods are:

(1) The traditional method of thawing fish is to thaw them in flowing tap water. Long thawing time will easily cause the freshness of the materials to deteriorate and the quality of the final product to deteriorate. The present invention thaws under the action of ultrasound, which can thaw the outer part and the core of the raw material at the same time, thereby realizing the freshness of the frozen processed product as it is when it is frozen; The chemical effect produces instantaneous high temperature and alternating temperature changes, instantaneous high pressure and pressure changes in the liquid, which can kill some bacteria, inactivate viruses, and even destroy the cell walls of some small microorganisms, so as to remove the adhesion on fish fillets. microbes, etc. Compared with microwave thawing, ultrasonic thawing can effectively avoid "cooking" in the thawing area, so that sushi fillets have a longer shelf life.

(2) The present invention adopts the synergistic effect of ultrasonic waves and disinfectant before fish filleting, after removing tails and scales, to effectively sterilize while completing cleaning.

(3) The present invention adopts dipping freezing method to process sushi fish fillets, and ultrasonic technology is used for the freezing process of fish fillets simultaneously. Its benefits lie in the enhanced heat and mass transfer process of ultrasonic waves, which shortens the freezing time and improves production efficiency; utilizes the cavitation mechanism and mechanical fluctuations of ultrasonic waves to promote crystallization nucleation, controls the distribution of crystal particle size, and suppresses the generation of large ice crystals to improve Quality of frozen fish fillets, etc. The introduction of ultrasonic waves in the freezing process can achieve rapid freezing and effectively improve the quality of frozen products, reduce the denaturation of fish meat protein, increase the water holding capacity of fish fillets, reduce the loss of nutrients and flavor substances after thawing, and maintain fresh taste. In the sense of "quick freezing".

The process of processing sushi fish fillets in the present invention is as follows: take live and fresh fish with scales as raw material, pass inspection, temporary storage in ice water, and pretreatment, or use frozen scaled fish as raw material, first thaw, and then remove the tail and scale , Ultrasonic cleaning, sectioning, trimming, insect picking, thorn removal, cleaning, ultrasonic quick freezing, grading, ice coating, packaging, metal detection, frozen storage and other processes to process sushi fish fillets.

The key control points of the processing process include the following aspects:

1. Pre-freezing treatment

(1) Raw material acceptance: inspect and purchase raw fish that meet the quality requirements from farms or suppliers.

(2) Temporary storage in ice water: Put fresh raw fish and live fish into low-temperature ice water to make them enter a coma state and store them temporarily.

(3) Pretreatment: including bloodletting, head removal, viscera removal and ice water washing, etc.

(4) Freezing and frozen storage: If the raw materials are not processed directly, the raw materials need to be frozen and stored in frozen storage.

(5) Frozen raw materials: Generally, the head and belly have been removed.

(6) Raw material delivery and thawing: Take raw materials from the frozen storage to the thawing field, and thaw them in the thawing tank under the action of ultrasonic waves with flowing ethanol aqueous solution. The ethanol concentration is 15% to 25%, and the temperature of the thawing solution is lower than 15°C The ultrasonic frequency is 20kHz~100kHz, the ultrasonic electric power is 500W~1000W, the ultrasonic thawing time is 10min~15min, until the fish is half-thawed, the fish body temperature is -5℃~0℃. The rest of the treatment is the same as fresh fish.

(7) Tail removal, descaling, and cleaning: immediately cut off the tail of the thawed raw materials, and remove the scales with a scaler; or manually remove the scales, press the fish head with the left hand, and remove the scales from the tail to the head along the dorsal fin. Collect and refrigerate for other uses. Clean the fish with heads, scales and viscera removed by using directly drinkable purified water with disinfectant (0.12mg/L～2.5mg/L of ozone or Tween-80) under the action of ultrasonic waves; Rinse with purified water to remove disinfectant residue. The ultrasonic frequency used is 20kHz-100kHz, the electric power is 200W-500W, and the ultrasonic action time is 2min-5min.

(8) Slicing: remove the fish from the conveyor belt, put the fish body flat on the chopping board, cut off the fish fillets from the fish vertebrae and the excised head, push the knife down along the fish vertebrae, and cut off one side of the fish fillet; Cut the fillets off one side. The extra-large fish fillets are then cut into two pieces, and the quality of the fish fillets is controlled within the specified range. The cut fish fillets should be placed in a container with crushed ice at the bottom in time, and covered with a small amount of crushed ice in time. When slicing, try to ensure that the fish fillets are as complete as possible.

(9) Trimming (picking worms): Check the cut fish fillets, trim incomplete fish fillets, remove fish bones remaining in the fish meat, and remove parasites. Check whether the fish fillet has belly meat and fish bones. If it is cut off, make sure that the knife edge is flat and arc-shaped from the tail to the head.

(10) De-stabbing: de-stabbing products can get a higher price in the market. Use special utensils to pull out along the direction of the thorn. In this process, special personnel should be arranged to check whether the thorns are completely removed.

(11) Cleaning (adding antioxidants), water control: first wash with ice water, drain and then clean with 0.3% sodium erythorbate ice water solution, and control water. When plated, the fish fillets should be arranged neatly.

2. Freezing treatment

Put the fish fillets into the freezing liquid, apply ultrasonic waves in the freezing liquid, and perform the dipping method to freeze the fish fillets under the action of ultrasonic waves. It is a 45%-60% ethanol solution, and the temperature of the frozen liquid is -30°C to -50°C. In order to avoid direct contact of the liquid refrigerant with the fish fillets, the fish fillets should be sealed and packaged before freezing. The freezing time is 5 minutes to 15 minutes.

3. After freezing

(1) Grading: The fish fillets are weighed with an electronic scale, and the fish fillets are divided into different specifications according to customer requirements.

(2) Ice coat: use 0.1% to 0.4% sodium erythorbate ice solution to coat the ice coat. The thickness of the glazing coat should be more than 1mm. When glazing the coat, pay attention to repairing the frozen blocks with uneven appearance.

(3) Packaging: Packaging must be carried out in a low temperature environment below -5°C. The packaging workshop must turn on ultraviolet light to sterilize 1 hour before packaging. All packaging tools, work clothes, shoes and hats, and hands of the staff must be disinfected regularly. Packaging materials must be clean and pre-cooled. Be careful not to make mistakes.

(4) Metal detection: Put the packaged product on the conveyor belt equipped with a metal detector to detect metal fragments.

(5) Frozen storage: quickly pack into cartons, and the product name, specification, net weight, factory name, code number, batch number, production date, etc. must be marked on the outside of the box, and quickly put into the frozen storage. The frozen storage temperature is below -18°C. The finished products should be clearly marked, stacked according to different grades, specifications, and batches, and placed neatly. The warehouse is clean and hygienic, and other foods with peculiar smell cannot be stored.

The quality of sushi fish fillets processed according to the method meets the following requirements.

(1) Sensory quality

See Table 1 for sensory quality requirements.

Table 1 Sensory Quality Requirements

(2) Physical and chemical quality

The physical and chemical quality should meet the requirements in Table 2.

Table 2 Physical and chemical quality requirements

(3) Safety and health quality

Safety and health indicators should meet the requirements in Table 3.

Table 3 Safety and Quality Requirements

Description of drawings

Accompanying drawing is the process flowchart of sushi fillet processing.

Detailed ways

Example one

Fresh sea bream is used as the raw material, and after temporary storage in ice water, it is killed alive and bled to clean the blood and impurities, remove the head, internal organs, tail and scales. Clean once with purified drinking water with 0.12 mg/L ozone added under the action of ultrasonic waves; then clean with purified water to remove ozone residues. The ultrasonic frequency used is 20 kHz, the electric power is 200 W, and the ultrasonic action time is 2 min. Afterwards, slice, trim, pick insects, remove thorns, wash with ice water first, drain and then wash with 0.3% sodium erythorbate ice water solution, control water, put fish fillets in 45%, -30 ℃ ethanol to freeze The fish fillets are frozen under the action of ultrasonic waves, the ultrasonic frequency is 20kHz, the electric power is 80W, and the ultrasonic freezing time is 13min, then they are graded, ice-coated with 0.3% sodium erythorbate ice solution, packaged, metal detected and frozen for storage. The product quality processed according to the above method meets the quality requirements of Table 1, Table 2, and Table 3.

Example two

Use frozen red sea bream as raw material, thaw in a thawing tank with a flowing ethanol solution under the action of ultrasonic waves, the ethanol concentration is 15%, the temperature of the thawing solution is lower than 15°C, the ultrasonic frequency is 20kHz, the ultrasonic electric power is 500W, and the ultrasonic thawing time is 10min. The fish is half-thawed, the temperature of the fish body is -5°C ~ 0°C, and then the tail, scale and other impurities are removed, and the purified water with 0.15mg/L ozone added under the action of ultrasonic waves can be washed once; Wash with purified water to remove ozone residue. The ultrasonic frequency used is 25Hz, the electric power is 250W, and the ultrasonic action time is 3min. Afterwards, slice, trim, pick insects, remove thorns, wash with ice water first, drain and then wash with 0.3% sodium erythorbate ice water solution, control the water, and freeze the fish fillets in 50% ethanol at -40°C Frozen fish fillets under the action of ultrasonic waves, the ultrasonic frequency is 40kHz, the electric power is 100W, the ultrasonic freezing time is 8min, and then graded, coated with ice-coated 0.3% sodium erythorbate ice solution, packaged, metal detected and frozen for storage. The product quality processed according to the above method meets the quality requirements of Table 1, Table 2, and Table 3.

Example three

Fresh tilapia is used as raw material, after being temporarily stored in ice water, it is killed alive and bled to clean the blood and impurities, remove the head, internal organs, tail and scales. Wash once with directly drinkable purified water added with 0.13 mg/L Tween-80 under the action of ultrasonic waves; then wash with purified water to remove Tween-80 residues. The ultrasonic frequency used is 40 kHz, the electric power is 300 W, and the ultrasonic action time is 4 min. Afterwards, slice, trim, pick insects, remove thorns, wash with ice water first, drain and then wash with 0.3% sodium erythorbate ice water solution, control the water, and freeze the fish fillets in 50% ethanol at -45°C The fish fillets are frozen under the action of ultrasonic waves, the ultrasonic frequency is 80kHz, the electric power is 100W, and the ultrasonic freezing time is 6min, then they are graded, coated with ice-coated 0.3% sodium erythorbate ice solution, packaged, metal detected and frozen for storage. The product quality processed according to the above method meets the quality requirements of Table 1, Table 2, and Table 3.

Example four

Using frozen tilapia as raw material, thaw in a thawing tank with a flowing ethanol solution under the action of ultrasonic waves. The ethanol concentration is 15%, the temperature of the thawing solution is lower than 15°C, the ultrasonic frequency is 40kHz, the ultrasonic electric power is 600W, and the ultrasonic thawing time is 8min. To the half-thawed state of the fish, the temperature of the fish body is -5°C to 0°C, then remove the tail, scale and other impurities, and wash once with directly drinking purified water with 0.18mg/L ozone added under the action of ultrasonic waves; Rinse with purified water to remove ozone residue. The ultrasonic frequency used is 80kHz, the electric power is 300W, and the ultrasonic action time is 5min. Afterwards, slice, trim, pick insects, remove thorns, wash with ice water first, drain and then wash with 0.3% sodium erythorbate ice water solution, control the water, and freeze the fish fillets in 60% ethanol at -50°C Frozen fish fillets in liquid solution under the action of ultrasonic waves, the ultrasonic frequency is 20kHz, the electric power is 40W, the ultrasonic freezing time is 7min, then graded, ice-coated with 0.3% sodium erythorbate ice solution, packaged, metal detected and frozen for storage. The product quality processed according to the above method meets the quality requirements of Table 1, Table 2, and Table 3.

The above embodiments have provided the preferred operation process and method of the present invention, but the specific content of the present invention is not limited by the embodiments.

Claims (7)

1. A processing method for sushi fish fillets, characterized in that: take live and fresh fish with scales as raw material, pass acceptance, temporary storage in ice water, pretreatment, or use frozen fish with scales as raw material, first ultrasonically thaw, then pass Tail removal, descaling, ultrasonic cleaning, sectioning, trimming, insect picking, thorn removal, cleaning, ultrasonic quick freezing, grading, ice coating, packaging, metal detection, frozen storage and other processes to process sushi fish fillets. 2. the processing method of a kind of sushi fillet as claimed in claim 1 is characterized in that: raw material is live fresh or frozen scale seawater fish or scale freshwater fish, as red sea bream, perch, tilapia. 3. The processing method of a kind of sushi fish fillet as claimed in claim 1, is characterized in that: when raw material is frozen fish, need ultrasonic thawing earlier, and thawing method is: thaw with flowing ethanol aqueous solution under the effect of ultrasonic wave in thawing tank , the ethanol concentration is 15% to 25%, the temperature of the thawing liquid is lower than 15°C, the ultrasonic frequency is 20kHz to 100kHz, the ultrasonic electric power is 500W to 1000W, and the ultrasonic thawing time is 10min to 15min, until the fish is half-thawed, the fish body temperature is -5 ℃～0℃. 4. the processing method of a kind of sushi fish fillets as claimed in claim 1 is characterized in that: the ultrasonic cleaning method before sectioning slices is: add disinfectant (0.12mg/L～2.5mg/L) under the effect of ultrasonic waves Ozone or Tween-80) purified water that can be used for direct drinking and washed once; then washed with purified water to remove the residue of disinfectant. The ultrasonic frequency used is 20kHz-100kHz, the electric power is 200W-500W, and the ultrasonic action time is 2min-5min. 5. the processing method of a kind of sushi fish fillets as claimed in claim 1 is characterized in that: before the fish fillets are supersonically frozen, the fish fillets are cleaned with 0.3% sodium erythorbate ice solution. 6. the processing method of a kind of sushi fish fillet as claimed in claim 1 is characterized in that: adopt the freezing fish fillet (abbreviation supersonic quick freezing) of ultrasonic-promoted liquid immersion quick-freezing method. The method of supersonic quick freezing is: put the fish fillets in 45%~60%, -30℃~-50℃ ethanol freezing liquid, and freeze the fish fillets under the action of ultrasonic waves. The ultrasonic frequency is 20kHz~1MHz, and the electric power is 40W~200W. Ultrasound freezing time is 5min ~ 15min. 7. The processing method of a kind of sushi fish fillets as claimed in claim 1, characterized in that: after the fish fillets are frozen, the ice coat is plated with 0.1% to 0.4% sodium erythorbate ice solution.

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