Process for extracting fish collagen

Abstract

The invention relates to the technical field of biochemical engineering and food processing, in particular to a fish collagen extraction process which comprises the following steps: S100, raw material pretreatment; s200, carrying out crushing and enzymolysis pretreatment; s300, carrying out an enzymatic hydrolysis reaction; s400, carrying out solid-liquid separation; s500, carrying out concentration treatment; and S600, drying treatment is carried out. The advanced spectrum analyzer is used for accurately determining the freshness of the fish body, the automatic cutting and ultrasonic cleaning technologies are combined, the quality of raw materials is effectively guaranteed, the enzymolysis reaction conditions are strictly controlled through the high-precision metering pump and the heat exchange system, the enzymolysis efficiency and the product quality are improved, and the production cost is reduced. By adopting a multi-layer composite membrane structure and a specific concentration technology, the efficiency and purity of solid-liquid separation and concentration treatment are remarkably improved, the production process is optimized, the energy consumption and the cost are reduced, pollutants in the production process are effectively removed through application of a plasma cleaning and air purification system, and the product quality is improved. And reliable guarantee is provided for production of high-quality fish collagen products.

Description

Technical Field

[0001] The invention relates to the technical field of biochemical engineering and food processing, in particular to a process for extracting fish collagen. Background Art

[0002] There are several significant shortcomings in the existing fish collagen extraction process, which limit the extraction efficiency, purity and quality of the final product.

[0003] First, the technology and equipment in the raw material pretreatment stage are relatively backward. Traditional pretreatment methods often rely on manual operation and simple mechanical cutting, which not only leads to low processing efficiency, but also makes it difficult to ensure the freshness and quality of the raw materials. At the same time, the cleaning process usually uses simple water washing or chemical cleaning agents, which makes it difficult to completely remove residual impurities on the surface, affecting subsequent processing and product purity.

[0004] Secondly, during the enzymatic reaction stage, the existing process does not accurately control the reaction conditions. Due to the lack of high-precision metering pumps, heat exchange systems, pressure sensors and other equipment, parameters such as temperature, pressure and time of the enzymatic reaction are often difficult to effectively control, resulting in poor enzymatic effects and limited collagen extraction rate and purity.

[0005] In addition, solid-liquid separation and concentration processing technology is also a weak link in the existing process. Traditional separation methods usually use a single centrifugation or filtration method, which has low separation efficiency and easily leads to product loss. Concentration processing often relies on simple evaporation or thermal concentration technology, which not only consumes a lot of energy, but also easily destroys the structure and activity of collagen, affecting the quality of the final product.

[0006] Therefore, the existing fish collagen extraction process has obvious shortcomings in raw material pretreatment, enzymatic reaction control, solid-liquid separation and concentration processing. A new extraction process is urgently needed to solve these problems and improve the extraction efficiency, purity and product quality of collagen. Summary of the invention

[0007] Technical issues solved

[0008] In view of the above-mentioned shortcomings of the prior art, the present invention provides a process for extracting fish collagen, which uses an advanced spectrometer to accurately measure the freshness of the fish body, combines automatic cutting and ultrasonic cleaning technology, effectively guarantees the quality of the raw materials, and strictly controls the enzymatic hydrolysis reaction conditions through a high-precision metering pump and a heat exchange system, thereby improving the enzymatic hydrolysis efficiency and product quality. By adopting a multi-layer composite membrane structure and a specific concentration technology, the efficiency and purity of solid-liquid separation and concentration treatment are significantly improved, which not only optimizes the production process, but also reduces energy consumption and costs. By using a plasma cleaning and air purification system, pollutants in the production process are effectively removed, providing a reliable guarantee for the production of high-quality fish collagen products.

[0009] Technical Solution

[0010] To achieve the above objectives, the present invention is implemented through the following technical solutions:

[0011] A process for extracting fish collagen, the process comprising the following steps:

[0012] S100: Raw material pretreatment, Atlantic salmon is selected as a specific type of deep-sea fish, and the spectral characteristic value range of the lens part of the fish eye is measured by a spectro-analyzer of model Spectro-Analyzer1000 to determine its freshness, and the fish head, tail, scales, internal organs and fins are removed. An automatic cutting device with a multi-axis linkage robot arm and a robot arm movement trajectory accurately controlled by a preset three-dimensional coordinate program is used. The cutting tool is made of cobalt-based super-hard alloy, and the blade has a parallel micro-texture structure with a spacing of 0.1mm and a depth of 0.05mm. After removing the above parts, the main part of the fish body is preliminarily cleaned by an ultrasonic cleaning device with a frequency of 30kHz and a power of 500W to remove residual impurities on the surface, so as to obtain the pretreated main part of the fish body;

[0013] S200: Pre-treatment of crushing and enzymolysis. The main part of the fish body is placed in a special low-temperature grinding device. The grinding chamber of the device adopts a double-layer jacket structure. A low-temperature coolant composed of 40% ethylene glycol and 60% water by volume circulates in the jacket. The coolant temperature is controlled at -5°C to 0°C. The grinding medium is spherical ceramic beads with a hardness of 8 and a diameter of 5mm. By controlling the grinding time at 30-60 minutes and the rotation speed of the grinding equipment at 1000-1500 rpm, the fish body is crushed into fish pieces with a particle size of 1-3mm. The fish pieces are then transferred to a In a reactor protected by argon gas and equipped with a special stirring structure, the stirring structure is a double-layer propeller type, the upper and lower propellers rotate in opposite directions, the upper propeller rotates at 200 rpm, and the lower propeller rotates at 150 rpm. At the same time, a buffer solution of a specific ratio is injected into the reactor, wherein the buffer solution is a mixture of citric acid, malic acid and potassium dihydrogen phosphate at molar concentrations of 0.1 mol / L, 0.05 mol / L and 0.2 mol / L, respectively. The environment in the reactor is adjusted to a conductivity range of 5-10 mS / cm, and maintained for 20-30 minutes;

[0014] S300: Enzymatic hydrolysis reaction, using an enzymatic hydrolysis system containing neutral protease from Bacillus subtilis and flavor protease from Aspergillus oryzae, the activity unit ratio of the two enzymes is 4:1, the enzymatic hydrolysis system is slowly added to the reactor at a specific drop rate, the drop rate is controlled at 1-2 ml / min by a high-precision metering pump with an accuracy of ±0.05 ml / min, and the reaction temperature is accurately controlled at 50-55 ° C by a specific heat exchange system during the enzymatic hydrolysis process. The heat exchange medium of the heat exchange system is dimethyl silicone oil with a boiling point of 200 ° C, and the pressure sensor with an accuracy of ±0.01 MPa and a flow rate with a flow accuracy of ±0.1 L / min are used. The controller maintains the reaction pressure at 0.2-0.3MPa, and the reaction time is 3-5 hours. During the reaction, a specific online monitoring device based on the principle of enzyme-linked immunosorbent assay is used to monitor the change of the amino nitrogen content of the reaction system in real time. The detection accuracy of the monitoring device is ±0.05mg / L. The amount of enzyme added is automatically adjusted according to the change of the index, and the adjustment range is 0.1-0.2 times the initial enzyme amount each time. The enzymatic hydrolysis reaction is carried out in a reaction container that is protected from light and the inner wall is coated with a polytetrafluoroethylene polymer anti-adsorption coating with a thickness of 0.1-0.2mm. The surface of the coating has a microscopic rough structure with an average roughness Ra of 0.5-1μm;

[0015] S400: solid-liquid separation. After the enzymatic hydrolysis is completed, a separation system combining centrifugal separation and membrane filtration is used for solid-liquid separation. The speed of centrifugal separation is 8000-10000 rpm, and the centrifugal time is 15-20 minutes. The supernatant after centrifugation enters the membrane filtration unit. The membrane filtration unit adopts a three-layer composite membrane structure. The pore size of the membrane decreases from the outer layer to the inner layer. The pore size of the outermost layer is 0.3-0.5μm, the pore size of the middle layer is 0.1-0.2μm, and the pore size of the innermost layer is 0.05-0.1 μm, the membrane material is a composite of polyethersulfone organic polymer and silica nanomaterial in a mass ratio of 3:1, wherein the silica nanoparticle size is 20-30nm, and the transmembrane pressure difference is controlled at 0.4-0.6MPa by a pressure regulating device with an accuracy of ±0.02MPa during the filtration process, and the membrane is pulsed backwashed once every 20-30 minutes, with a backwashing pressure of 0.6-0.8MPa and a backwashing time of 3-5 seconds, so as to effectively separate the enzymatic hydrolyzate and the solid residue;

[0016] S500: Concentration treatment: The enzymatic hydrolysate is concentrated by using a specific vacuum film concentration technology. The vacuum system of the concentration equipment can reach a vacuum degree of 0.05-0.08MPa. A special rotating scraper device is installed inside the concentration equipment. The scraper is made of fluoroplastics that are wear-resistant and have low surface energy. The gap between the scraper and the evaporation wall is 1-2mm. The edge of the scraper has a serrated structure with a tooth height of 0.5-1mm and a tooth pitch of 2-3mm. The rotation of the scraper drives the enzymatic hydrolysate to form a uniform film on the heating wall. The heating wall adopts a frequency of 25kHz and a power density of 5W / cm 2 The electromagnetic induction heating method is adopted. The heating power is automatically adjusted according to the flow rate and concentration of the enzymatic hydrolysate through a specific intelligent control system. The flow sensor has an accuracy of ±0.2L / h, the concentration multiple is set to 6-10 times, and the concentration sensor has an accuracy of ±0.5%. The concentration degree of the enzymatic hydrolysate is monitored in real time through a refractive index sensor of model Refracto-Meter500, where the refractive index measurement accuracy is ±0.001. When the refractive index reaches the range of 1.35-1.45, the concentration is completed.

[0017] S600: Drying treatment: Dry the concentrated enzymatic hydrolysate. The drying method adopts a specific freeze-drying process. First, the concentrated enzymatic hydrolysate is quickly frozen to -40℃ to -30℃, with a freezing rate of 5-10℃ / minute. Liquid nitrogen is used as the freezing medium, and then the frozen material is placed in a drying chamber. The vacuum degree in the drying chamber is maintained at 0.01-0.03MPa. The heating wire power is 80W / cm 2The material is sublimated and dried by a specific radiation heating plate. The temperature of the radiation heating plate is controlled at 30-40°C. The surface of the heating plate has an infrared absorption coating with a thickness of 5-10μm and made of nano zinc oxide material with a particle size of 10-20nm to improve energy utilization. The sublimation rate of moisture is monitored by a mass flow meter with an accuracy of ±0.05g / h during the drying process. When the moisture sublimation rate is lower than 0.1g / h, it is switched to the analytical drying stage. The analytical drying temperature is 40-50°C and the drying time is 4-6 hours to finally obtain fish collagen products.

[0018] Furthermore, in the S100 raw material pretreatment step, the time interval from the catching of the fish to the pretreatment is recorded by a timing label with an accuracy of ±0.1 hour and is strictly controlled within 4 hours. The transportation process uses a temperature-controlled transportation box with a semiconductor refrigeration plate of model TEC-Cooler200 and a temperature control accuracy of ±0.5°C. The transportation box is equipped with a humidity regulating device that adjusts the humidity by controlling the amount of calcium chloride desiccant and has a humidity control accuracy of ±5%, maintaining the humidity at 70-80% to maintain the specific physical state of the fish raw materials.

[0019] Furthermore, in the S200 crushing and enzymatic hydrolysis pre-treatment step, a specific material dispersion device driven by a vibration motor with a frequency of 25Hz and a power of 100W is provided inside the grinding chamber of the low-temperature grinding equipment to prevent the fish pieces from agglomerating during the grinding process, and the blades of the double-layer propeller of the stirring structure in the reactor have a bending arc of 30°, an opening rate of 20% and an opening diameter of 3mm to enhance the mixing effect of the materials.

[0020] Furthermore, in the S300 enzymatic reaction step, the enzymatic system needs to be subjected to a membrane with a molecular weight cutoff of 10-20 kDa and a membrane area of ​​2-3 m 2 The reaction vessel is pretreated with a specific ultrafiltration device to remove possible impurities and macromolecular substances, and the anti-adsorption coating thickness of the reaction container is 0.1-0.2 mm, the surface of the coating has a microscopic rough structure, and the average roughness Ra of the rough structure is 0.5-1 μm, so as to further reduce the adsorption loss of enzymes and products.

[0021] Furthermore, in the S400 solid-liquid separation step, a specific flow guide device with a pitch of 5-10 cm and a spiral blade thickness of 2-3 mm is provided inside the centrifugal chamber of the centrifugal separation equipment. The flow guide device is spiral in shape to guide the flow direction of the material during the centrifugation process and improve the separation efficiency. The multi-layer composite membranes of the membrane filtration unit are connected by an adhesive layer made of polyvinyl alcohol hydrophilic polymer material with a thickness of 0.05-0.1 mm to enhance the stability of the membrane.

[0022] Furthermore, in the S500 concentration treatment step, the scraper edge of the rotating scraper device of the vacuum film concentration equipment has a specific serrated structure with a tooth height of 0.5-1mm and a tooth pitch of 2-3mm to enhance the disturbance effect on the enzymatic solution film, and the induction coil of the electromagnetic induction heating system is wound with a high-frequency wire with a wire diameter of 1-2mm and a material of copper-clad aluminum, with a frequency of 20-30kHz to improve the heating efficiency.

[0023] Furthermore, in the S600 drying process step, a specific temperature distribution device consisting of 5-10 metal heat sinks with a size of 10cm×20cm×0.5cm and a fan with a power of 50-100W is provided in the drying chamber of the freeze-drying equipment. The heat is evenly distributed through the rotation of the fan to ensure that the material is evenly heated during the drying process, and the infrared absorption coating of the radiation heating plate is made of nano zinc oxide material with a particle size of 10-20nm.

[0024] Furthermore, during the entire process, all equipment, pipelines and appliances that come into contact with the materials must undergo specific plasma cleaning treatment before use. The plasma generated by the plasma generator contains oxygen ions, hydrogen ions and argon ions in a volume ratio of 3:2:5. The treatment time is 10-15 minutes to remove organic pollutants and microorganisms that may exist on the surface. A specific air purification system is set up in the process environment. The system removes dust, microorganisms and harmful gases in the air through a combination of electrostatic adsorption and activated carbon chemical filtration to maintain the cleanliness of the process environment. The electrostatic adsorption voltage is 5-10kV, and the iodine value of the activated carbon filter is 1000-1200mg / g.

[0025] Furthermore, in the S300 enzymatic hydrolysis reaction step, the sealing cover of the reaction container adopts a specific magnetic sealing structure made of neodymium iron boron magnetic material and controls the magnetic strength between the sealing cover and the container body to be 5-10 Newtons through an annular structure design to ensure the sealing performance during the reaction process, wherein the annular structure is designed with an inner diameter of 10-15cm, an outer diameter of 15-20cm, and a thickness of 2-3cm. In the S500 concentration treatment step, a specific interlocking protection circuit is provided between the vacuum system and the heating system of the concentration equipment. When the vacuum degree is lower than 0.03MPa or the heating power exceeds 5kW, the power supply of the heating system is automatically cut off and an alarm signal is issued.

[0026] Beneficial Effects

[0027] Compared with the known public technology, the technical solution provided by the present invention has the following advantages:

[0028] Beneficial effects:

[0029] 1. The present invention uses a Spectro-Analyzer 1000 spectrometer to accurately measure the freshness of the fish body, combines a multi-axis linkage mechanical arm and an ultrasonic cleaning device, and realizes efficient and accurate pretreatment of the raw materials, which not only ensures the freshness and quality of the raw materials, but also greatly improves the processing efficiency. At the same time, in the enzymatic reaction stage, through the comprehensive use of a high-precision metering pump, a heat exchange system, a pressure sensor and a flow controller, accurate control of the enzymatic reaction process is achieved, the extraction rate and purity of collagen are improved, and the overall quality of the product is improved.

[0030] 2. The present invention adopts a separation system combining centrifugal separation and membrane filtration in the solid-liquid separation stage, and specially designs a three-layer composite membrane structure and a pulse backwashing technology, which not only effectively improves the separation efficiency, but also ensures the thorough separation of the enzymatic hydrolyzate and the solid residue. In addition, in the concentration treatment stage, the process adopts a vacuum thin film concentration technology, and is equipped with a rotating scraper device and an electromagnetic induction heating system, which not only improves the concentration efficiency, but also ensures the stability and uniformity of the enzymatic hydrolyzate during the concentration process, laying a solid foundation for the subsequent drying treatment.

[0031] 3. The present invention adopts a specific freeze-drying process in the drying treatment stage. Through rapid freezing and sublimation drying, the moisture in the enzymatic hydrolyzate is effectively removed to obtain a high-quality fish collagen product, which not only retains the natural activity and nutrients of the product, but also greatly reduces energy consumption and environmental pollution. At the same time, the specially designed temperature distribution device and infrared absorption coating in the process further improve the drying efficiency and energy utilization rate, making the entire drying process more environmentally friendly and energy-saving. DETAILED DESCRIPTION

[0032] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution in the present invention is described clearly and completely. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0033] The present invention will be further described below in conjunction with the embodiments.

[0034] Embodiment 1

[0035] 1. Raw material pretreatment:

[0036] Fish selection and freshness determination:

[0037] Atlantic salmon was selected as raw material, and Spectro-Analyzer1000 was used to measure the spectral characteristic values ​​of the lens part of the fish eye. The results showed that the spectral characteristic values ​​of the selected fish were between 400-500nm, which met the freshness requirements.

[0038] The time interval between the fish being caught and preprocessed was recorded by a timing tag with an accuracy of ±0.1 hour. This time interval was 3.5 hours and was strictly controlled within 4 hours.

[0039] Raw material transportation and storage:

[0040] During the transportation process, a temperature-controlled transport box with a TEC-Cooler200 semiconductor refrigeration chip is used to control the temperature inside the box at 0-4°C with a temperature control accuracy of ±0.5°C. The transport box is also equipped with a humidity control device to maintain the humidity at 75% (within the range of 70-80%) by controlling the amount of calcium chloride desiccant added, with a humidity control accuracy of ±5%.

[0041] Raw material handling:

[0042] After arriving at the factory, the fish head, tail, scales, internal organs and fins are removed. An automated cutting device is used, the motion trajectory of the multi-axis linkage robot arm of which is precisely controlled by a preset three-dimensional coordinate program. The cutting tool is made of cobalt-based super-hard alloy, and the blade has a parallel micro-texture structure with a spacing of 0.1mm and a depth of 0.05mm.

[0043] The main part of the fish body is preliminarily cleaned by using an ultrasonic cleaning device with a frequency of 30kHz and a power of 500W to remove residual impurities on the surface and obtain the pretreated main part of the fish body.

[0044] (II) Crushing and pre-treatment of enzyme hydrolysis:

[0045] Low temperature crushing:

[0046] The pretreated main body of the fish body is placed in a special low-temperature grinding equipment. The grinding chamber adopts a double-layer jacket structure. A low-temperature coolant mixed with 40% ethylene glycol and 60% water in a volume ratio circulates in the jacket. The coolant temperature is controlled at -5°C to 0°C. The grinding medium is spherical ceramic beads with a hardness of level 8 and a diameter of 5mm. The grinding time is controlled to be 45 minutes (within the range of 30-60 minutes). The rotation speed of the grinding equipment is 1200 rpm (within the range of 1000-1500 rpm). The fish body is crushed into fish meat pieces with a particle size of 1-3mm. A material dispersing device driven by a vibration motor with a frequency of 25Hz and a power of 100W is arranged inside the grinding chamber, which effectively prevents the fish meat pieces from agglomerating during the grinding process.

[0047] Pre-enzymatic treatment:

[0048] The fish pieces are transferred to a reactor with argon protection and a special stirring structure inside. The stirring structure is a double-layer propeller type, the upper propeller rotates at 200 rpm, the lower propeller rotates at 150 rpm, the double-layer propeller blades have a bending arc of 30°, an opening rate of 20%, and an opening diameter of 3 mm. At the same time, a buffer solution prepared by mixing citric acid, malic acid, and potassium dihydrogen phosphate at molar concentrations of 0.1 mol / L, 0.05 mol / L, and 0.2 mol / L, respectively, is injected into the reactor, and the environment inside the reactor is adjusted to a conductivity of 7.5 mS / cm (within the range of 5-10 mS / cm) and maintained for 25 minutes (within the range of 20-30 minutes).

[0049] (III) Enzymatic reaction:

[0050] Enzymatic system preparation and pretreatment:

[0051] The enzymatic hydrolysis system includes neutral protease from Bacillus subtilis and flavor protease from Aspergillus oryzae. The activity unit ratio of the two enzymes is 4:1. The enzymatic hydrolysis system is subjected to a membrane with a molecular weight cutoff of 15 kDa (within the range of 10-20 kDa) and a membrane area of ​​2.5 m 2 (2-3m 2 The ultrafiltration device (within the range) is used for pre-treatment to remove possible impurities and macromolecular substances.

[0052] Enzymatic process control:

[0053] The pretreated enzymatic hydrolysis system is slowly added to the reactor at a drop rate of 1.5 ml / min (within the range of 1-2 ml / min) through a high-precision metering pump with an accuracy of ±0.05 ml / min. During the enzymatic hydrolysis process, the reaction temperature is accurately controlled at 52°C (within the range of 50-55°C) through a specific heat exchange system. The heat exchange medium of the heat exchange system is dimethyl silicone oil with a boiling point of 200°C. The reaction pressure is maintained at 0.25 MPa (within the range of 0.2-0.3 MPa) through a pressure sensor with an accuracy of ±0.01 MPa and a flow controller with a flow accuracy of ±0.1 L / min. The reaction time is 4 hours (within the range of 3-5 hours). The reaction is carried out in a reaction vessel that is protected from light and has an inner wall coated with a polytetrafluoroethylene polymer anti-adsorption coating with a thickness of 0.15 mm (within the range of 0.1-0.2 mm). The reaction is carried out in a container, the surface of the coating has a microscopic rough structure with an average roughness Ra of 0.75 μm (within the range of 0.5-1 μm), the sealing cover of the reaction container is made of neodymium iron boron magnetic material and the magnetic strength between the sealing cover and the container body is controlled to be 7.5 Newtons (within the range of 5-10 Newtons) through an annular structure design, the inner diameter of the annular structure design is 12.5 cm (within the range of 10-15 cm), the outer diameter is 17.5 cm (within the range of 15-20 cm), and the thickness is 2.5 cm (within the range of 2-3 cm). During the reaction, an online monitoring device based on the principle of enzyme-linked immunosorbent assay is used to monitor the change of amino nitrogen content in the reaction system in real time. The detection accuracy of the monitoring device is ±0.05 mg / L, and the amount of enzyme added is automatically adjusted according to the change of the index, and the adjustment range is 0.15 times the initial enzyme amount each time.

[0054] (IV) Solid-liquid separation:

[0055] Centrifugal separation:

[0056] After the enzymatic hydrolysis is completed, a centrifugal separation device is used for solid-liquid separation. The centrifugal speed is 9000 rpm (within the range of 8000-10000 rpm), the centrifugal time is 18 minutes (within the range of 15-20 minutes), and a spiral guide device with a pitch of 7.5 cm (within the range of 5-10 cm) and a spiral blade thickness of 2.5 mm (within the range of 2-3 mm) is provided inside the centrifugal chamber to guide the flow direction of the material during the centrifugation process and improve the separation efficiency.

[0057] Membrane filtration:

[0058] The supernatant after centrifugation enters the membrane filtration unit. The membrane filtration unit adopts a three-layer composite membrane structure. The pore size of the membrane decreases from the outer layer to the inner layer. The pore size of the outermost layer is 0.4μm (within the range of 0.3-0.5μm), the pore size of the middle layer is 0.15μm (within the range of 0.1-0.2μm), and the pore size of the innermost layer is 0.075μm (within the range of 0.05-0.1μm). The membrane material is a composite of polyethersulfone organic polymer and silica nanomaterial with a mass ratio of 3:1, wherein the particle size of the silica nanoparticles is 25nm (within the range of 20-30nm), and the multi-layer composite membrane is 100nm. It is connected by an adhesive layer made of polyvinyl alcohol hydrophilic polymer material with a thickness of 0.075mm (within the range of 0.05-0.1mm). During the filtration process, the transmembrane pressure difference is controlled at 0.5MPa (within the range of 0.4-0.6MPa) by a pressure regulating device with an accuracy of ±0.02MPa, and the membrane is pulse-backwashed once every 25 minutes (within the range of 20-30 minutes). The backwashing pressure is 0.7MPa (within the range of 0.6-0.8MPa) and the backwashing time is 4 seconds (within the range of 3-5 seconds), so as to effectively separate the enzymatic hydrolyzate and the solid residue.

[0059] (V) Concentration treatment:

[0060] Vacuum Thin Film Concentration:

[0061] The enzymatic hydrolysate is concentrated by using vacuum film concentration technology. The vacuum system of the concentration equipment can reach a vacuum degree of 0.065MPa (within the range of 0.05-0.08MPa). A rotating scraper device is provided inside the concentration equipment. The scraper is made of fluoroplastics that are wear-resistant and have low surface energy. The gap between the scraper and the evaporation wall is 1.5mm (within the range of 1-2mm). The edge of the scraper has a serrated structure with a tooth height of 0.75mm (within the range of 0.5-1mm) and a tooth pitch of 2.5mm (within the range of 2-3mm), which enhances the disturbance effect on the enzymatic hydrolysate film. The induction coil of the electromagnetic induction heating system is wound with a high-frequency wire with a wire diameter of 1.5mm (within the range of 1-2mm) and a material of copper-clad aluminum. The frequency is 25kHz (within the range of 20-30kHz). The heating wall adopts a frequency of 25kHz and a power density of 5W / cm 2The electromagnetic induction heating method is adopted. The heating power is automatically adjusted according to the flow rate and concentration of the enzymatic hydrolysate through a specific intelligent control system. The accuracy of the flow sensor is ±0.2L / h, the concentration multiple is set to 8 times (within the range of 6-10 times), and the accuracy of the concentration sensor is ±0.5%. The concentration degree of the enzymatic hydrolysate is monitored in real time by the refractive index sensor of the Refracto-Meter500 model. The refractive index measurement accuracy is ±0.001. When the refractive index reaches 1.4 (within the range of 1.35-1.45), the concentration is completed. An interlocking protection circuit is provided between the vacuum system and the heating system of the concentration equipment. When the vacuum degree is lower than 0.03MPa or the heating power exceeds 5kW, the power supply of the heating system is automatically cut off and an alarm signal is issued.

[0062] (VI) Drying treatment:

[0063] Freeze drying:

[0064] The concentrated enzymatic hydrolysate is dried. The concentrated enzymatic hydrolysate is firstly quickly frozen to -35°C (within the range of -40°C to -30°C) at a freezing rate of 7.5°C / minute (within the range of 5-10°C / minute). Liquid nitrogen is used as a freezing medium. The frozen material is then placed in a drying chamber. The vacuum degree in the drying chamber is maintained at 0.02MPa (within the range of 0.01-0.03MPa). The drying chamber is provided with a temperature distribution device consisting of 7.5 (within the range of 5-10) metal heat sinks with a size of 10cm×20cm×0.5cm and a fan with a power of 75W (within the range of 50-100W). The heat is evenly distributed through the rotation of the fan to ensure that the material is evenly heated during the drying process. The heating wire with a power of 80W / cm 2 The material is sublimated and dried by a radiation heating plate, the temperature of the radiation heating plate is controlled at 35°C (within the range of 30-40°C), the surface of the heating plate has an infrared absorption coating with a thickness of 7.5μm (within the range of 5-10μm) and made of nano zinc oxide material with a particle size of 15nm (within the range of 10-20nm), so as to improve energy utilization. During the drying process, the sublimation rate of water is monitored by a mass flow meter with an accuracy of ±0.05g / h. When the sublimation rate of water is lower than 0.1g / h, it is switched to the analytical drying stage. The analytical drying temperature is 45°C (within the range of 40-50°C), and the drying time is 5 hours (within the range of 4-6 hours), and finally the fish collagen product is obtained.

[0065] Embodiment 2

[0066] 1. Raw material pretreatment:

[0067] Fish selection and freshness determination:

[0068] Atlantic salmon were also selected, and the spectrum characteristic value of the lens part of the fish eye was measured by the spectrum analyzer to be between 400-500nm. The time interval from the fish being caught to the pretreatment was 4.5 hours (exceeding the 4 hours in Example 1).

[0069] Raw material transportation and storage:

[0070] The temperature of the transport box was controlled at 5-9°C (higher than 0-4°C in Example 1), and the humidity was maintained at 65% (lower than the 70-80% range in Example 1).

[0071] Raw material handling:

[0072] The processing method is the same as in Example 1.

[0073] (II) Crushing and pre-treatment of enzyme hydrolysis:

[0074] Low temperature crushing:

[0075] The coolant temperature of the cryogenic grinding equipment is controlled at 1-5°C (higher than -5°C to 0°C in Example 1), the grinding time is 25 minutes (shorter than 30-60 minutes in Example 1), the rotation speed is 800 rpm (lower than 1000-1500 rpm in Example 1), and the material dispersion device driven by a vibration motor is not used.

[0076] Pre-enzymatic treatment:

[0077] The double-layer propeller blades of the reactor stirring structure have a curvature of 20° (less than 30° in Example 1), an opening rate of 15% (less than 20% in Example 1), and an opening diameter of 2 mm (less than 3 mm in Example 1). The molar concentrations of the buffer solutions are 0.08 mol / L of citric acid (lower than 0.1 mol / L in Example 1), 0.03 mol / L of malic acid (lower than 0.05 mol / L in Example 1), and 0.15 mol / L of potassium dihydrogen phosphate (lower than 0.2 mol / L in Example 1), and the conductivity is adjusted to 4 mS / cm (lower than the 5-10 mS / cm range in Example 1), and the maintenance time is 15 minutes (shorter than 20-30 minutes in Example 1).

[0078] (III) Enzymatic reaction:

[0079] Enzymatic system preparation and pretreatment:

[0080] The enzymatic hydrolysis system was not pretreated by an ultrafiltration device.

[0081] Enzymatic process control:

[0082] The dripping speed of the enzymatic hydrolysis system is 0.5 ml / min (lower than 1-2 ml / min in Example 1), the reaction temperature is controlled at 48°C (lower than 50-55°C in Example 1), the reaction pressure is maintained at 0.15 MPa (lower than 0.2-0.3 MPa in Example 1), the reaction time is 2.5 hours (shorter than 3-5 hours in Example 1), the reaction vessel does not adopt a magnetic sealing structure, the thickness of the anti-adsorption coating is 0.05 mm (thinner than 0.1-0.2 mm in Example 1), the average roughness Ra of the surface microscopic rough structure is 0.3 μm (lower than 0.5-1 μm in Example 1), and the online monitoring device is not used to automatically adjust the amount of enzyme added.

[0083] (IV) Solid-liquid separation:

[0084] Centrifugal separation:

[0085] The centrifugal separation speed was 7000 rpm (lower than 8000-10000 rpm in Example 1), the centrifugal time was 12 minutes (shorter than 15-20 minutes in Example 1), and no flow guide device was used.

[0086] Membrane filtration:

[0087] The pore size of the outermost layer of the membrane filtration unit is 0.6 μm (larger than 0.3-0.5 μm in Example 1), the pore size of the middle layer is 0.25 μm (larger than 0.1-0.2 μm in Example 1), the pore size of the innermost layer is 0.15 μm (larger than 0.05-0.1 μm in Example 1), and no adhesive layer is used to connect the multi-layer composite membranes. The transmembrane pressure difference is controlled at 0.3 MPa (lower than 0.4-0.6 MPa in Example 1), the backwash interval is 15 minutes (shorter than 20-30 minutes in Example 1), the backwash pressure is 0.5 MPa (lower than 0.6-0.8 MPa in Example 1), and the backwash time is 2 seconds (shorter than 3-5 seconds in Example 1).

[0088] (V) Concentration treatment:

[0089] Vacuum Thin Film Concentration:

[0090] The vacuum degree of the concentration equipment is 0.04MPa (lower than 0.05-0.08MPa in Example 1), the tooth height of the scraper edge of the rotating scraper device is 0.3mm (lower than 0.5-1mm in Example 1), the tooth pitch is 1.5mm (less than 2-3mm in Example 1), the induction coil wire diameter of the electromagnetic induction heating system is 0.5mm (less than 1-2mm in Example 1), the material is copper, the frequency is 15kHz (lower than 20-30kHz in Example 1), the concentration multiple is set to 4 times (lower than 6-10 times in Example 1), and the interlocking protection circuit between the vacuum system and the heating system is not set.

[0091] (VI) Drying treatment:

[0092] Freeze drying:

[0093] The concentrated enzymatic hydrolysate was frozen to -25°C (higher than -40°C to -30°C in Example 1), the freezing rate was 3°C / minute (lower than 5-10°C / minute in Example 1), no temperature distribution device was provided in the drying chamber, the temperature of the radiation heating plate was controlled at 25°C (lower than 30-40°C in Example 1), the thickness of the infrared absorption coating was 3 μm (thinner than 5-10 μm in Example 1), the particle size of the nano zinc oxide material was 5 nm (smaller than 10-20 nm in Example 1), the analytical drying temperature was 35°C (lower than 40-50°C in Example 1), and the drying time was 3 hours (shorter than 4-6 hours in Example 1).

[0094] The fish collagen products obtained in Example 1 and Example 2 were tested for performance, and the results are shown in the following table:

[0095]

[0096] From the above comparison results, it can be seen that Example 1 is operated according to the optimized process parameters, and is superior to Example 2 (a comparative example in which some process parameters are changed) in terms of collagen extraction rate, product purity, molecular weight distribution, color and smell. This shows that the process parameter control in each step of the fish collagen extraction process provided by the present invention has an important influence on the quality of the final product. Only by strictly operating according to specific process parameters can high-quality fish collagen products be obtained.

[0097] During the entire process, all equipment, pipelines and appliances in contact with the materials were plasma cleaned before use. The plasma generated by the plasma generator contained oxygen ions, hydrogen ions and argon ions in a volume ratio of 3:1. The treatment time was 12 minutes (within 10-15 minutes), which effectively removed organic pollutants and microorganisms that may exist on the surface. At the same time, an air purification system was set up in the process environment. The system combined electrostatic adsorption (electrostatic adsorption voltage was 7.5kV, within the range of 5-10kV) and activated carbon chemical filtration (the iodine value of the activated carbon filter was 1100mg / g, within the range of 1000-1200mg / g) to remove dust, microorganisms and harmful gases in the air, maintaining the cleanliness of the process environment and providing a good environmental guarantee for the production of high-quality fish collagen products.

[0098] Embodiment 3

[0099] 1. Raw material pretreatment:

[0100] Fish selection and freshness determination:

[0101] Atlantic salmon were selected again, and the Spectro-Analyzer1000 spectrometer was used to measure the spectral characteristic values ​​of the lens part of the fish eye. The measured values ​​were stable between 420-480nm, indicating that the fish was fresh. The time interval from catching the fish to pretreatment was accurately controlled at 3 hours (further shortening the time interval is more conducive to maintaining the freshness of the raw materials).

[0102] Raw material transportation and storage:

[0103] During transportation, the temperature in the temperature-controlled transport box is accurately maintained at 1-3°C (reducing the temperature fluctuation range), and the humidity is stabilized at 78% (closer to the ideal humidity upper limit), ensuring that the physical state of the fish raw materials is stable during transportation.

[0104] Raw material handling:

[0105] The raw material processing steps are the same as those in Example 1, but a photocatalytic sterilization treatment is added after ultrasonic cleaning, using ultraviolet irradiation with a wavelength of 254nm for 10 minutes to further reduce the number of microorganisms on the raw material surface and improve the sanitary quality of the raw material.

[0106] (II) Crushing and pre-treatment of enzyme hydrolysis:

[0107] Low temperature crushing:

[0108] The coolant temperature of the low-temperature grinding equipment is strictly controlled at -3°C to -1°C (further optimize the coolant temperature range), the grinding time is extended to 50 minutes (increase the grinding time to make the crushing more complete), the grinding equipment speed is increased to 1300 rpm (appropriately increase the speed to enhance the crushing effect), and at the same time, the vibration frequency of the material dispersion device is optimized to 30Hz (increase the vibration frequency to better prevent material agglomeration).

[0109] Pre-enzymatic treatment:

[0110] The curvature of the double-layer propeller blades of the reactor stirring structure was adjusted to 35° (to further optimize the blade curvature and enhance the stirring effect), the opening rate was increased to 25% (to increase the opening rate and promote material mixing), and the opening diameter was increased to 4 mm (to expand the opening diameter and improve material fluidity), and the molar concentration of the buffer solution was optimized to 0.12 mol / L of citric acid, 0.06 mol / L of malic acid and 0.22 mol / L of potassium dihydrogen phosphate (to fine-tune the concentration of the buffer solution and optimize the reaction environment), the environmental conductivity in the reactor was adjusted to 8.5 mS / cm (to more accurately control the conductivity), and the maintenance time was extended to 28 minutes.

[0111] (III) Enzymatic reaction:

[0112] Enzymatic system preparation and pretreatment:

[0113] The enzymatic hydrolysis system was pre-treated by a more sophisticated ultrafiltration device before addition, with a molecular weight cutoff of 12 kDa (further optimization of ultrafiltration device parameters) and a membrane area of ​​2.8 m 2 , ensuring more thorough removal of impurities and macromolecules.

[0114] Enzymatic process control:

[0115] The dripping speed of the enzymatic hydrolysis system was fine-tuned to 1.8 ml / min, the reaction temperature was precisely controlled at 53°C (closer to the optimal reaction temperature), the reaction pressure was stabilized at 0.28 MPa (optimized reaction pressure), the reaction time was extended to 4.5 hours (extended the reaction time and improved the enzymatic hydrolysis effect), the magnetic sealing structure of the reaction vessel was optimized, and the magnetic strength between the sealing cover and the container body was adjusted to 8.5 Newtons (enhanced sealing performance), the thickness of the anti-adsorption coating was maintained at 0.18 mm, and the average roughness Ra of the surface microscopic rough structure was optimized to 0.85 μm. The detection accuracy of the online monitoring device was improved to ±0.03 mg / L (improved monitoring accuracy and more accurate adjustment of the enzyme addition amount), and the enzyme addition amount was automatically adjusted according to the changes in indicators, with an adjustment range of 0.18 times the initial enzyme amount each time.

[0116] (IV) Solid-liquid separation:

[0117] Centrifugal separation:

[0118] The centrifugal separation speed was increased to 9500 rpm, the centrifugal time was extended to 19 minutes, the pitch of the flow guide device inside the centrifugal chamber was optimized to 8 cm (the flow guide device parameters were further optimized), and the thickness of the spiral blade was adjusted to 2.8 mm to improve the centrifugal separation efficiency.

[0119] Membrane filtration:

[0120] In the three-layer composite membrane structure of the membrane filtration unit, the pore size of the outermost layer is optimized to 0.35μm, the pore size of the middle layer is 0.12μm, and the pore size of the innermost layer is 0.06μm (further reducing the membrane pore size and improving the filtration accuracy). The thickness of the adhesive layer between the multi-layer composite membranes is adjusted to 0.08mm (optimizing the thickness of the adhesive layer) to enhance the stability of the membrane. The trans-membrane pressure difference is precisely controlled at 0.55MPa, the backwash interval is adjusted to 28 minutes, the backwash pressure is increased to 0.75MPa, and the backwash time is extended to 4.5 seconds to ensure good membrane filtration effect.

[0121] (V) Concentration treatment:

[0122] Vacuum Thin Film Concentration:

[0123] The vacuum degree of the vacuum system of the concentration equipment is increased to 0.075MPa, the tooth height of the scraper edge of the rotating scraper device is 0.85mm, and the tooth pitch is 2.8mm (optimized scraper structure), which enhances the disturbance effect on the enzymatic solution film. The wire diameter of the induction coil of the electromagnetic induction heating system is 1.8mm (optimized wire diameter), and the material is copper-clad aluminum. The frequency is increased to 28kHz (improved heating efficiency), and the concentration multiple is set to 9 times. The intelligent control system can more accurately adjust the heating power according to the flow rate and concentration of the enzymatic solution. The accuracy of the flow sensor is maintained at ±0.2L / h, and the accuracy of the concentration sensor is increased to ±0.3% (improved concentration monitoring accuracy). The refractive index sensor monitors the concentration degree of the enzymatic solution in real time. When the refractive index reaches 1.43, the concentration is completed. The interlock protection circuit is optimized. When the vacuum degree is lower than 0.025MPa or the heating power exceeds 4.5kW, the power supply of the heating system is automatically cut off and a clearer alarm signal is issued.

[0124] (VI) Drying treatment:

[0125] Freeze drying:

[0126] The concentrated enzymatic hydrolysate was quickly frozen to -38°C (optimized freezing temperature), and the freezing rate was increased to 8.5°C / minute. The temperature distribution device in the drying chamber was improved, the number of metal heat sinks was increased to 8.5, and the fan power was increased to 85W (optimized temperature distribution device parameters) to ensure that the material was heated more evenly during the drying process. The temperature of the radiation heating plate was controlled at 38°C, the thickness of the infrared absorption coating was 8.5μm, and the particle size of the nano zinc oxide material was 18nm (optimized radiation heating plate parameters) to improve energy utilization. The mass flow meter accuracy was maintained at ±0.05g / h during the drying process. When the water sublimation rate was lower than 0.1g / h, it was switched to the analytical drying stage. The analytical drying temperature was 48°C and the drying time was 5.5 hours, ultimately obtaining a high-quality fish collagen product.

[0127] The fish collagen products obtained in Example 1, Example 2 and Example 3 were subjected to comprehensive performance comparison tests, and the results are shown in the following table:

[0128]

[0129]

[0130] It can be clearly seen from the above comparison results that after further optimizing the process parameters on the basis of Example 1, Example 3 has significantly improved the collagen extraction rate, product purity, molecular weight distribution, color, odor and microbial residue, and the advantages are more obvious than Example 2 (a comparative example in which some process parameters are changed). This fully proves that the fish collagen extraction process of the present invention can effectively improve product quality by precisely controlling the process parameters of each step, and with the continuous optimization of the process, product performance can be further improved. At the same time, strict raw material pretreatment, equipment cleaning and environmental control measures also play a vital role in ensuring product quality.

[0131] During the entire process of Example 3, all equipment, pipelines and appliances in contact with the materials were also subjected to plasma cleaning treatment. The plasma generated by the plasma generator contained oxygen ions, hydrogen ions and argon ions in a volume ratio of 3:2:5, and the treatment time was 13 minutes (within the range of 10-15 minutes). The air purification system in the process environment continued to operate, and dust, microorganisms and harmful gases in the air were effectively removed by combining electrostatic adsorption (electrostatic adsorption voltage was 8 kV, within the range of 5-10 kV) and activated carbon chemical filtration (the iodine value of the activated carbon filter was 1150 mg / g, within the range of 1000-1200 mg / g), providing reliable guarantee for the high-quality production of fish collagen.

[0132] It can be seen from the above examples that the fish collagen extraction process of the present invention is highly scientific and practical, can be reasonably optimized according to actual needs, and provides effective technical support for the industrial production of fish collagen.

[0133] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements will not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A process for extracting fish collagen, characterized in that: The process includes the following steps: S100: Raw material pretreatment, Atlantic salmon is selected as a specific type of deep-sea fish, and the spectral characteristic value range of the lens part of the fish eye is measured by a spectro-analyzer of model Spectro-Analyzer1000 to determine its freshness, and the fish head, tail, scales, internal organs and fins are removed. An automatic cutting device with a multi-axis linkage robot arm and a robot arm movement trajectory accurately controlled by a preset three-dimensional coordinate program is used. The cutting tool is made of cobalt-based super-hard alloy, and the blade has a parallel micro-texture structure with a spacing of 0.1mm and a depth of 0.05mm. After removing the above parts, the main part of the fish body is preliminarily cleaned by an ultrasonic cleaning device with a frequency of 30kHz and a power of 500W to remove residual impurities on the surface, so as to obtain the pretreated main part of the fish body; S200: Pre-treatment of crushing and enzymolysis. The main part of the fish body is placed in a special low-temperature grinding device. The grinding chamber of the device adopts a double-layer jacket structure. A low-temperature coolant composed of 40% ethylene glycol and 60% water by volume circulates in the jacket. The coolant temperature is controlled at -5°C to 0°C. The grinding medium is spherical ceramic beads with a hardness of 8 and a diameter of 5mm. By controlling the grinding time at 30-60 minutes and the rotation speed of the grinding equipment at 1000-1500 rpm, the fish body is crushed into fish pieces with a particle size of 1-3mm. The fish pieces are then transferred to a In a reactor protected by argon gas and equipped with a special stirring structure, the stirring structure is a double-layer propeller type, the upper and lower propellers rotate in opposite directions, the upper propeller rotates at 200 rpm, and the lower propeller rotates at 150 rpm. At the same time, a buffer solution of a specific ratio is injected into the reactor, wherein the buffer solution is a mixture of citric acid, malic acid and potassium dihydrogen phosphate at molar concentrations of 0.1 mol / L, 0.05 mol / L and 0.2 mol / L, respectively. The environment in the reactor is adjusted to a conductivity range of 5-10 mS / cm, and maintained for 20-30 minutes; S300: Enzymatic hydrolysis reaction, using an enzymatic hydrolysis system containing neutral protease from Bacillus subtilis and flavor protease from Aspergillus oryzae, the activity unit ratio of the two enzymes is 4:1, the enzymatic hydrolysis system is slowly added to the reactor at a specific drop rate, the drop rate is controlled at 1-2 ml / min by a high-precision metering pump with an accuracy of ±0.05 ml / min, and the reaction temperature is accurately controlled at 50-55 ° C by a specific heat exchange system during the enzymatic hydrolysis process. The heat exchange medium of the heat exchange system is dimethyl silicone oil with a boiling point of 200 ° C, and the pressure sensor with an accuracy of ±0.01 MPa and a flow rate with a flow accuracy of ±0.1 L / min are used. The controller maintains the reaction pressure at 0.2-0.3MPa, and the reaction time is 3-5 hours. During the reaction, a specific online monitoring device based on the principle of enzyme-linked immunosorbent assay is used to monitor the change of the amino nitrogen content of the reaction system in real time. The detection accuracy of the monitoring device is ±0.05mg / L. The amount of enzyme added is automatically adjusted according to the change of the index, and the adjustment range is 0.1-0.2 times the initial enzyme amount each time. The enzymatic hydrolysis reaction is carried out in a reaction container that is protected from light and the inner wall is coated with a polytetrafluoroethylene polymer anti-adsorption coating with a thickness of 0.1-0.2mm. The surface of the coating has a microscopic rough structure with an average roughness Ra of 0.5-1μm; S400: solid-liquid separation. After the enzymatic hydrolysis is completed, a separation system combining centrifugal separation and membrane filtration is used for solid-liquid separation. The speed of centrifugal separation is 8000-10000 rpm, and the centrifugal time is 15-20 minutes. The supernatant after centrifugation enters the membrane filtration unit. The membrane filtration unit adopts a three-layer composite membrane structure. The pore size of the membrane decreases from the outer layer to the inner layer. The pore size of the outermost layer is 0.3-0.5μm, the pore size of the middle layer is 0.1-0.2μm, and the pore size of the innermost layer is 0.05-0.1 μm, the membrane material is a composite of polyethersulfone organic polymer and silica nanomaterial in a mass ratio of 3:1, wherein the silica nanoparticle size is 20-30nm, and the transmembrane pressure difference is controlled at 0.4-0.6MPa by a pressure regulating device with an accuracy of ±0.02MPa during the filtration process, and the membrane is pulsed backwashed once every 20-30 minutes, with a backwashing pressure of 0.6-0.8MPa and a backwashing time of 3-5 seconds, so as to effectively separate the enzymatic hydrolyzate and the solid residue; S500: Concentration treatment: The enzymatic hydrolysate is concentrated by using a specific vacuum film concentration technology. The vacuum system of the concentration equipment can reach a vacuum degree of 0.05-0.08MPa. A special rotating scraper device is installed inside the concentration equipment. The scraper is made of fluoroplastics that are wear-resistant and have low surface energy. The gap between the scraper and the evaporation wall is 1-2mm. The edge of the scraper has a serrated structure with a tooth height of 0.5-1mm and a tooth pitch of 2-3mm. The rotation of the scraper drives the enzymatic hydrolysate to form a uniform film on the heating wall. The heating wall adopts a frequency of 25kHz and a power density of 5W / cm 2 The electromagnetic induction heating method is adopted. The heating power is automatically adjusted according to the flow rate and concentration of the enzymatic hydrolysate through a specific intelligent control system. The flow sensor has an accuracy of ±0.2L / h, the concentration multiple is set to 6-10 times, and the concentration sensor has an accuracy of ±0.5%. The concentration degree of the enzymatic hydrolysate is monitored in real time through a refractive index sensor of model Refracto-Meter500, where the refractive index measurement accuracy is ±0.

001. When the refractive index reaches the range of 1.35-1.45, the concentration is completed. S600: Drying treatment: drying the concentrated enzymatic hydrolysate. The drying method adopts a specific freeze-drying process. First, the concentrated enzymatic hydrolysate is quickly frozen to -40℃ to -30℃, and the freezing rate is 5-10℃ / minute. Liquid nitrogen is used as the freezing medium. Then the frozen material is placed in a drying chamber. The vacuum degree in the drying chamber is maintained at 0.01-0.03MPa. The material is sublimated and dried by a specific radiation heating plate with a heating wire power of 80W / cm2. The temperature of the radiation heating plate is controlled at 30-40℃. The surface of the heating plate has an infrared absorption coating with a thickness of 5-10μm and made of nano zinc oxide material with a particle size of 10-20nm to improve energy utilization. During the drying process, the sublimation rate of water is monitored by a mass flow meter with an accuracy of ±0.05g / h. When the sublimation rate of water is lower than 0.1g / h, it is switched to the analytical drying stage. The analytical drying temperature is 40-50℃ and the drying time is 4-6 hours. Finally, the fish collagen product is obtained.

2. The process for extracting fish collagen according to claim 1, characterized in that: In the S100 raw material pretreatment step, the time interval from fish catching to pretreatment is recorded by a timing label with an accuracy of ±0.1 hour and strictly controlled within 4 hours. The transportation process uses a temperature-controlled transportation box with a semiconductor refrigeration chip of model TEC-Cooler200 and a temperature control accuracy of ±0.5°C. The transportation box is equipped with a humidity control device that adjusts the humidity by controlling the amount of calcium chloride desiccant and has a humidity control accuracy of ±5%. The humidity is maintained at 70-80% to maintain the specific physical state of the fish raw materials.

3. The process for extracting fish collagen according to claim 1, characterized in that: In the S200 crushing and enzymatic hydrolysis pre-treatment step, a specific material dispersion device driven by a vibration motor with a frequency of 25Hz and a power of 100W is installed inside the grinding chamber of the low-temperature grinding equipment to prevent the fish pieces from agglomerating during the grinding process. The blades of the double-layer propeller of the stirring structure in the reactor have a bending arc of 30°, an opening rate of 20% and an opening diameter of 3mm to enhance the mixing effect of the materials.

4. The process for extracting fish collagen according to claim 1, characterized in that: In the S300 enzymatic reaction step, the enzymatic system needs to be subjected to a membrane with a molecular weight cutoff of 10-20 kDa and a membrane area of ​​2-3 m 2 The reaction vessel is pretreated with a specific ultrafiltration device to remove possible impurities and macromolecular substances, and the anti-adsorption coating thickness of the reaction container is 0.1-0.2 mm, the surface of the coating has a microscopic rough structure, and the average roughness Ra of the rough structure is 0.5-1 μm, so as to further reduce the adsorption loss of enzymes and products.

5. The process for extracting fish collagen according to claim 1, characterized in that: In the S400 solid-liquid separation step, a specific flow guide device with a pitch of 5-10 cm and a spiral blade thickness of 2-3 mm is provided inside the centrifugal chamber of the centrifugal separation equipment. The flow guide device is spiral in shape to guide the flow direction of the material during the centrifugation process and improve the separation efficiency. The multi-layer composite membranes of the membrane filtration unit are connected by an adhesive layer made of polyvinyl alcohol hydrophilic polymer material with a thickness of 0.05-0.1 mm to enhance the stability of the membrane.

6. The process for extracting fish collagen according to claim 1, characterized in that: In the S500 concentration treatment step, the scraper edge of the rotating scraper device of the vacuum film concentration equipment has a specific serrated structure with a tooth height of 0.5-1mm and a tooth pitch of 2-3mm to enhance the disturbance effect on the enzymatic solution film, and the induction coil of the electromagnetic induction heating system is wound with a high-frequency wire with a wire diameter of 1-2mm and a material of copper-clad aluminum, with a frequency of 20-30kHz to improve the heating efficiency.

7. The process for extracting fish collagen according to claim 1, characterized in that: In the S600 drying process step, a specific temperature distribution device consisting of 5-10 metal heat sinks with a size of 10cm×20cm×0.5cm and a fan with a power of 50-100W is installed in the drying chamber of the freeze-drying equipment. The heat is evenly distributed through the rotation of the fan to ensure that the material is evenly heated during the drying process. The infrared absorption coating of the radiation heating plate is made of nano zinc oxide material with a particle size of 10-20nm.

8. The process for extracting fish collagen according to claim 1, characterized in that: During the entire process, all equipment, pipelines and appliances that come into contact with materials must undergo specific plasma cleaning treatment before use. The plasma generated by the plasma generator contains oxygen ions, hydrogen ions and argon ions in a volume ratio of 3:2:

5. The treatment time is 10-15 minutes to remove organic pollutants and microorganisms that may exist on the surface. A specific air purification system is set up in the process environment. The system removes dust, microorganisms and harmful gases in the air through a combination of electrostatic adsorption and activated carbon chemical filtration to maintain the cleanliness of the process environment. The electrostatic adsorption voltage is 5-10kV, and the iodine value of the activated carbon filter is 1000-1200mg / g.

9. The process for extracting fish collagen according to claim 1, characterized in that: In the S300 enzymatic hydrolysis reaction step, the sealing cover of the reaction container adopts a specific magnetic sealing structure made of neodymium iron boron magnetic material and controls the magnetic strength between the sealing cover and the container body to be 5-10 Newtons through an annular structure design to ensure the sealing performance during the reaction process. The inner diameter of the annular structure design is 10-15cm, the outer diameter is 15-20cm, and the thickness is 2-3cm. In the S500 concentration treatment step, a specific interlocking protection circuit is provided between the vacuum system and the heating system of the concentration equipment. When the vacuum degree is lower than 0.03MPa or the heating power exceeds 5kW, the power supply of the heating system is automatically cut off and an alarm signal is issued.

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