A dried fish paste and a method of making the same

Abstract

The application discloses dry fish glue and a preparation method thereof, and belongs to the technical field of aquatic product processing. The preparation method comprises the following steps: soaking fresh fish glue in a first soaking liquid containing 0.2% chlorogenic acid and 0.1%-0.3% pueraria powder by mass percentage at 25°C or below for 1 hour, then performing micro-nano bubble ozone cleaning for 15 minutes, and controlling the ozone concentration to be 0.5-0.8 ppm; after cleaning, extruding at a speed of 3-8 m / min under a pressure of 0.3-0.8 MPa; after extruding, sequentially soaking in a second soaking liquid containing 0.5%-2% schisandra powder by mass percentage and a third soaking liquid containing 0.01%-0.03% phospholipase by mass percentage for 1 hour, and then manually rinsing for 30 minutes; then airing for 12 hours in an environment at 30-35°C, performing rolling brush cleaning by using soft brush filaments, and placing the dry fish glue on a ventilated rack after spinning drying, and performing air circulation drying at 35-40°C for 48-72 hours, so that the dry fish glue is obtained. The method can efficiently remove blood water and fat, effectively remove fishy smell, and gently protect the texture of the fish glue, and the obtained product is uniform in color, free of floating oil and good in elasticity.

Description

Technical Field

[0001] This invention belongs to the field of aquatic product processing technology, specifically relating to a dried fish glue and its preparation method. Background Technology

[0002] Fish maw, also known as fish bladder, is a product made from the dried swim bladder of fish. Along with bird's nest and shark fin, it is considered a traditional and rare ingredient, renowned as one of the "Eight Treasures of the Sea" and "Marine Ginseng." However, improving the quality of raw fish maw faces numerous challenges. Firstly, raw fish maw is naturally covered with an oily film and contains a high amount of fat, while also retaining a certain amount of blood. The fat not only significantly masks the inherent umami flavor of the fish maw, but its oxidation also intensifies the fishy smell; the residual blood easily causes the fish maw to appear dark red, severely affecting its appearance. Secondly, current production methods heavily rely on manual washing to remove blood and fat, resulting in extremely low efficiency, long processing times, and a tendency to damage the surface of the fish maw, affecting its texture and elasticity. Furthermore, prolonged soaking during the washing process and the pH level of the soaking solution can also damage the texture of the fish maw.

[0003] Therefore, there is an urgent need in this field for a method to produce dried fish maw that can efficiently remove blood and fat, effectively deodorize, and at the same time maximize the protection of the fish collagen fiber structure and improve the taste and quality of fish maw. Summary of the Invention

[0004] In view of the problems of difficulty in removing blood and fat, strong fishy smell, low efficiency of manual cleaning and easy damage to the collagen structure in the above-mentioned prior art, the present invention provides a dried fish glue and its preparation method to solve the above-mentioned technical defects.

[0005] The technical solution adopted by this invention to solve its technical problem is as follows: In a first aspect, the present invention provides a method for preparing dried fish glue, comprising the following steps: S1. Add fresh fish maw to the soaking tank and soak it in the first soaking solution at a temperature below 25°C for 1 hour. The first soaking solution consists of 0.2% chlorogenic acid, 0.1%-0.3% kudzu root powder, and the remainder water by mass percentage. After soaking, start the micro-nano bubble ozone cleaner to perform bubble cleaning, controlling the ozone concentration to 0.5-0.8 ppm, to obtain fish maw after one cleaning. S2. The fish maw after one cleaning is fed into an extruder and extruded at a speed of 3-8 m / min under a pressure of 0.3-0.8 MPa to obtain the extruded fish maw. S3. First, add the squeezed fish maw to the second soaking solution and soak it at below 25°C for 1 hour. The second soaking solution consists of 0.5%-2% Schisandra chinensis powder and the remainder water by mass percentage. After removing the fish maw, you will get the fish maw soaked in Schisandra chinensis. Then, add the fish maw soaked in Schisandra chinensis to the third soaking solution and soak it at below 25°C for 1 hour. The third soaking solution consists of 0.01%-0.03% phospholipase and the remainder water by mass percentage. This will give you the fish maw after a second cleaning. S4. After the second cleaning, add the fish maw to water below 25℃ and rinse by hand for 30 minutes to obtain the rinsed fish maw. S5. Dry the rinsed fish maw at 30-35℃ for 12 hours to obtain dried fish maw. S6. Send the dried fish maw into the fish maw roller brush cleaning machine for roller brush cleaning to obtain the roller brush cleaned fish maw. S7. Place the fish maw that has been cleaned by the roller brush into the spin dryer and spin dry to obtain the dried fish maw. S8. Place the spun-dry fish maw on a ventilated rack and dry it through air circulation to obtain dried fish maw.

[0006] As a preferred technical solution, the temperature of air circulation drying in step S8 is 35-40℃, and the drying time is 48-72 hours.

[0007] As a preferred technical solution, the mass percentage of kudzu root powder in the first soaking solution in step S1 is 0.2%.

[0008] As a preferred technical solution, the mass percentage of Schisandra chinensis powder in the second soaking solution in step S3 is 1%.

[0009] As a preferred technical solution, the mass percentage of phospholipase in the third soaking solution in step S3 is 0.02%.

[0010] As a preferred technical solution, the operating conditions for the roller brush cleaning in step S6 are: roller brush rotation speed 20-60 r / min, conveying speed 3-8 m / min, and spraying pressure 0.1-0.3 MPa.

[0011] As a preferred technical solution, the bubbling cleaning time in step S1 is 15 minutes.

[0012] As a preferred technical solution, the bristles used in the fish glue roller cleaning machine in step S6 are soft bristles.

[0013] Secondly, the present invention provides a dried fish glue prepared according to any of the above-mentioned methods.

[0014] Compared with the prior art, the dried fish glue and its preparation method provided by the present invention have the following beneficial effects: (1) Through the synergistic effect of chlorogenic acid and kudzu root powder in the first soaking solution, combined with the physical peeling and oxidation of the micro-nano bubble ozone cleaner, and the mechanical extrusion of the extruder, the blood and fat in the fish glue can be effectively removed.

[0015] (2) By neutralizing the fishy smell substances with Schisandra chinensis powder in the second soaking solution and decomposing the fishy smell precursor substances (phospholipids) with phospholipids in the third soaking solution, the fishy smell is effectively removed and the fishy smell is significantly reduced.

[0016] (3) The entire process adopts a gentle cleaning method (micro-nano bubble gentle turbulence, soft brush bristle roller brush, low speed and low pressure operation) to avoid high-speed rinsing, stirring paddle friction or strong kneading; at the same time, low temperature air circulation drying is adopted to avoid high temperature causing collagen denaturation, so as to fully preserve the hardness, elasticity and chewiness of fish maw.

[0017] (4) Use equipment such as micro-nano bubble ozone cleaning, extruder, and roller brush cleaning machine to replace traditional manual cleaning, which greatly shortens the processing time, improves production efficiency, and ensures the uniformity of product quality.

[0018] (5) Through the color-protecting effect of chlorogenic acid and multiple steps of washing, drying, and rolling, the dried fish glue produced has a uniform color, no blood residue, dark red color, and a clean surface without floating oil, which meets the needs of the high-end market. Attached Figure Description

[0019] Other features, objects, and advantages of this application will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings: Figure 1 This is a flowchart of the method for preparing dried fish glue according to the present invention; Figure 2 These are scanning electron microscope (SEM) microstructure comparison images of fish glue from the experimental group and the control group of this invention. Figure 3 These are comparison images of the actual appearance of the fish maw from the experimental group and the control group of this invention. Detailed Implementation

[0020] The present application will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, only the parts relevant to the invention are shown in the accompanying drawings.

[0021] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0022] In a first aspect, the present invention provides a method for preparing dried fish glue. Figure 1 A flowchart illustrating the method for preparing dried fish glue according to the present invention is shown, as follows: Figure 1 As shown, the manufacturing method includes the following steps S1 to S8.

[0023] S1: Add fresh fish maw to the soaking tank and soak it in the first soaking solution at a temperature below 25°C for 1 hour. The first soaking solution consists of 0.2% chlorogenic acid, 0.1%-0.3% kudzu root powder, and the remainder water by mass percentage. After soaking, start the micro-nano bubble ozone cleaner to perform bubble cleaning, and control the ozone concentration to 0.5-0.8 ppm to obtain fish maw after one cleaning.

[0024] Specifically, fresh fish maw (raw fish maw) is added to a soaking tank, along with the first soaking solution, and soaked at below 25°C for 1 hour. The first soaking solution is prepared as follows: weigh 0.2% chlorogenic acid and 0.1%-0.3% kudzu root powder by mass percentage, with the remainder being water, and mix thoroughly. After soaking, a micro-nano bubbling ozone cleaner is started for bubbling cleaning for 15 minutes, with the ozone concentration inside the cleaner controlled at 0.5-0.8 ppm.

[0025] In this step, the micro-nano bubble ozone cleaner generates tiny bubbles with a large specific surface area, allowing them to quickly diffuse and penetrate deep into the crevices and folds of the fish maw, adsorbing and removing blood, grease, and other impurities from the surface and deeper layers. Simultaneously, the ozone generated by the micro-nano bubble ozone cleaner oxidizes trimethylamine, a substance with a fishy odor, and kills microorganisms. The water flow generated by the micro-nano bubble ozone cleaner is a gentle turbulent flow, without high-speed rinsing, agitation, or vigorous kneading, keeping the fish maw in a gentle, suspended state without damaging its texture.

[0026] Chlorogenic acid can bind with Fe in hemoglobin 2+ / Fe 3+ The complexation process causes the blood-colored substances to dissociate and be carried away by the water flow, inhibiting the oxidation and blackening of heme, thus removing blood stains and protecting the color. The phenolic hydroxyl groups in chlorogenic acid are hydrophilic, while the aromatic rings are lipophilic, allowing it to emulsify and disperse oils, reduce surface tension, and cause fat to detach from the surface of the fish glue. Simultaneously, chlorogenic acid, as an antioxidant, can reduce the damage to collagen caused by oxidation.

[0027] The isoflavones and chlorogenic acid in kudzu root powder work synergistically to promote blood dissolution; kudzu root polysaccharides can adsorb free hemoglobin, forming flocculent suspensions that are easily adsorbed and floated away by micro-nano bubbles; kudzu root saponins and polysaccharides have mild emulsifying properties, which can encapsulate oil droplets to form emulsions that are removed with the water flow. When chlorogenic acid is combined with kudzu root powder, it can form a protective film on the surface of fish glue, preventing collagen denaturation and degradation, and thus improving the hardness, elasticity, and chewiness of the fish glue.

[0028] After processing in step S1, fish maw that has been washed once is obtained.

[0029] S2: The fish glue after the first cleaning is fed into an extruder and extruded at a speed of 3-8 m / min under a pressure of 0.3-0.8 MPa to obtain the extruded fish glue.

[0030] Specifically, the fish glue obtained after one cleaning in step S1 is fed into an extruder. The extrusion pressure is set to 0.3-0.8 MPa, and the conveyor belt speed is 3-8 m / min to physically extrude the fish glue. Extrusion removes free water, residual blood, and surface oil from the interstitial spaces of the fish glue tissue. Simultaneously, the extrusion pressure promotes mild cross-linking of collagen fibers, thereby enhancing the hardness and elasticity of the fish glue, resulting in a denser, thicker, and more uniformly shaped fish glue tissue. The collagen structure is not damaged during the extrusion process. After this step, extruded fish glue is obtained.

[0031] S3: First, add the extruded fish glue to the second soaking solution and soak it at below 25°C for 1 hour. The second soaking solution consists of 0.5%-2% Schisandra chinensis powder and the remainder water by mass percentage. After soaking, the fish glue soaked in Schisandra chinensis is obtained. Then, add the fish glue soaked in Schisandra chinensis to the third soaking solution and soak it at below 25°C for 1 hour. The third soaking solution consists of 0.01%-0.03% phospholipase and the remainder water by mass percentage. The fish glue is then cleaned twice.

[0032] Specifically, this step consists of two soaking processes: Step 1: Soaking: Add the extruded fish glue obtained in step S2 to the second soaking solution and soak for 1 hour at below 25°C. The second soaking solution is prepared as follows: Weigh 0.5%-2% of Schisandra chinensis powder by mass percentage, with the remainder being water, and mix thoroughly. The organic acids in Schisandra chinensis powder can neutralize the fishy odor substances such as trimethylamine in the fish glue, directly reducing the fishy smell; the flavonoid antioxidants in Schisandra chinensis powder can reduce fat oxidation and protect the texture of the fish glue. After soaking, remove the fish glue to obtain the Schisandra chinensis-soaked fish glue.

[0033] The second soaking step: Add the fish maw soaked in the Schisandra chinensis extract from the previous step to the third soaking solution and soak at below 25°C for 1 hour. The third soaking solution is prepared by weighing 0.01%-0.03% phospholipase by mass percentage, with the remainder being water, and mixing thoroughly. Phospholipase (including phospholipase A1 and A2) can catalyze the hydrolysis of phospholipid molecules (such as phosphatidylcholine) in fish maw, generating lysophospholipids and free fatty acids, thereby reducing the content of fishy odor precursors and inhibiting fishy odor production at its source. Simultaneously, reducing the phosphatidylcholine content reduces its interference with collagen cross-linking, allowing collagen to cross-link more fully and enhancing the elasticity and toughness of the fish maw. After this step, the fish maw is obtained after a second cleaning.

[0034] S4: Add the fish maw that has been washed twice to water below 25°C and rinse manually for 30 minutes to obtain rinsed fish maw.

[0035] Specifically, the fish maw obtained after secondary cleaning in step S3 is added to water below 25°C and rinsed manually for 30 minutes. This step is a gentle rinsing, designed to remove residual soaking liquid and loosened blood, fat, and other impurities from the surface of the fish maw, which is fundamentally different from the heavy manual cleaning described in the background art. After this step, rinsed fish maw is obtained.

[0036] S5: The rinsed fish maw is sun-dried for 12 hours in an outdoor environment at 30-35℃ to obtain sun-dried fish maw. Sun-drying within this temperature range promotes the slow seepage of solid fish oil from the inside of the fish maw to the surface, while avoiding excessively high temperatures that could cause deformation and shrinkage of collagen fibers or accelerated fat oxidation on the surface of the fish maw. Those skilled in the art should understand that the sun-drying in this step can also be carried out in a well-ventilated, temperature-controlled environment (such as a constant-temperature oven or drying room), without being affected by weather or other natural factors, and has good repeatability. After this step, sun-dried fish maw with fish oil seeping from its surface is obtained.

[0037] S6: The dried fish maw is sent to a fish maw roller brush cleaning machine for roller brush cleaning to obtain the roller brush cleaned fish maw.

[0038] As preferred operating conditions, the roller brush rotation speed for roller brush cleaning is 20-60 r / min, the conveying speed is 3-8 m / min, and the spraying pressure is 0.1-0.3 MPa (low-pressure spraying). The fish glue roller brush cleaning machine uses soft brush bristles. The soft brush bristles, operating at low speed and low pressure, gently remove fish oil, blood, mucus, impurities, and surface fascia adhering to the fish glue surface using purely physical methods. This process does not cause mechanical tearing or collagen denaturation, thus preserving the textural properties of the fish glue while ensuring cleaning effectiveness. After this step, the fish glue is obtained after roller brush cleaning.

[0039] S7: Place the fish maw cleaned by the roller brush into a spin dryer to remove excess moisture from the surface and interior of the fish maw. After this step, the dried fish maw is obtained.

[0040] S8: Place the spun-dry fish maw on a ventilated rack and dry it in circulating air at 35-40℃ for 48-72 hours to obtain dried fish maw. This low-temperature, long-time drying method avoids collagen denaturation and structural damage caused by high temperatures, effectively preserving the elasticity and chewiness of the fish maw, while allowing the internal moisture to dissipate evenly. After drying, the finished dried fish maw product is obtained.

[0041] Secondly, the present invention provides a dried fish glue prepared according to any of the above-mentioned methods.

[0042] The technical solution of the present invention will be described in detail below through specific embodiments. This embodiment uses the above-described manufacturing method, and the preferred key parameters for each step are as follows (taking test group 2 as an example): S1: Add fresh fish maw to the soaking tank and soak it in the first soaking solution at a temperature below 25°C for 1 hour. The first soaking solution consists of 0.2% chlorogenic acid and 0.2% kudzu root powder by mass percentage. After soaking, perform micro-nano bubbling ozone cleaning for 15 minutes with an ozone concentration of 0.7 ppm.

[0043] S2: The fish maw after one cleaning is fed into an extruder and extruded at a speed of 5 m / min under a pressure of 0.5 MPa.

[0044] S3: First, add the squeezed fish maw to the second soaking solution and soak it at below 25°C for 1 hour. The second soaking solution consists of 1% Schisandra chinensis powder and the remainder water by weight. After removing the fish maw, add it to the third soaking solution and soak it at below 25°C for 1 hour. The third soaking solution consists of 0.02% phospholipase and the remainder water by weight.

[0045] S4: After the second cleaning, add the fish maw to water below 25℃ and rinse by hand for 30 minutes.

[0046] S5: Dry the rinsed fish maw at 32℃ for 12 hours.

[0047] S6: Send the dried fish maw into the fish maw roller brush cleaning machine for roller brush cleaning. The operating conditions are: roller brush speed 40r / min, conveying speed 5m / min, spraying pressure 0.2MPa, and soft brush bristles.

[0048] S7: Place the fish maw that has been cleaned by the roller brush into the spin dryer and spin dry.

[0049] S8: Place the spun-dry fish maw on a ventilated rack and air-dry it at 38°C for 60 hours.

[0050] The dried fish glue prepared according to the above parameters has a fat content of 0.75%, a trimethylamine content of 6.44 μg / g, a collagen content of 78.04%, a hardness of 13.79 N, an elasticity of 0.85, and a chewiness of 13.38 N. All of these indicators are superior to those of the control groups.

[0051] To verify the technical effects of this invention, commercially available fresh fish swim bladders were used as raw materials, and comparative tests were conducted according to the following groups. The test indicators included fat content, trimethylamine content, collagen content, textural properties, microstructure, and physical appearance.

[0052] Except for the parameters listed in Table 1, the other operating conditions for each experimental group and control group are the same as those for the corresponding steps S1-S8 in the method of this invention. Specifically, the drying temperature in S5 is uniformly set at 32℃ for all groups, and the drying time is 12 hours; the air circulation drying time in S8 is uniformly set at 60 hours. The parameter settings for each experimental group and control group are shown in the table below.

[0053] Table 1. Parameter settings for the experimental group and the control group

[0054] The following testing methods were used to determine each indicator: (1) Determination of fat content: The fat content in dried fish glue was determined according to the method for determining fat in GB 5009.6.

[0055] (2) Trimethylamine content determination: The volatile flavor compounds were determined by headspace-solid phase microextraction (HS-SPME) combined with GC-MS. 2g of dried fish glue samples from each experimental group and control group were added to a final volume of 20mL with distilled water and homogenized in a high-speed homogenizer at 10000r / min for 2min. 5mL of homogenate, 1g of sodium chloride, 2μL of 5μL / mL cyclohexanone solution, and a magnetic stir bar were added to the extraction flask. The solid phase extraction head was inserted and adsorbed at 60℃ for 30min. Then, the extraction head was inserted into the GC-MS inlet for sample injection and desorption was performed at 250℃ for 5min. Chromatographic conditions: DB-5MS capillary column (30m × 250um, 0.25um); Temperature program: initial temperature 40℃, hold for 2 min; increase to 120℃ at 5℃ / min, hold for 3 min; increase to 230℃ at 10℃ / min, hold for 3 min; Carrier gas He, flow rate 1.0 mL / min, split ratio 20:1. Mass spectrometry conditions: Ion source (EI) temperature 230℃, electron energy 70 eV, scan mode Scan, scan range 30–450 amu. Qualitative analysis was performed using computer-based matching with the Wiley and NIST 08 standard libraries. Quantitative analysis was performed using peak area normalization, calculated using the following formula: ; In the formula For the content of a certain component , The peak area of ​​a certain component. The peak area of ​​the internal standard. For the quality of internal standard , The mass of the test sample added (i.e., 2g of dried fish glue).

[0056] (3) Collagen content determination: The collagen content in dried fish glue was determined by the hydroxyproline method according to the amino acid detection method in GB 5009.124.

[0057] (4) Texture determination: The dried fish maw sample was placed in a bowl, filled with water, and sealed (simulating the filling method of ready-to-eat fish maw products). It was then placed in an autoclave and sterilized at 121℃ for 11 minutes. The sample was removed from the bowl, the residual liquid on the surface was wiped off, and the surface of the fish maw was trimmed until it was smooth. A cylindrical probe was selected for full texture testing. The specific parameters were: P / 36R probe, speed before test 1.0 mm / s, trigger force 5 g, test speed 1.0 mm / s, compression ratio 50%, interval time 3.0 sec, and speed after test 3.0 mm / s. The hardness, elasticity, and chewiness of the fish maw were evaluated.

[0058] The results of fat content measurement in each experimental group and control group are shown in Table 2. In the following tables (Tables 2-4), different superscript letters after the data in the same column indicate significant differences between groups (P<0.05), and the same letter indicates no significant difference.

[0059] Table 2. Fat content (%) of fish maw processed by different drying methods

[0060] As shown in Table 2, the fat content of experimental groups 1-3 and control group 12 was significantly lower than that of other groups, indicating that only by using the technical solution of this invention could the expected experimental effect be obtained. Too high or too low a ratio of kudzu root powder, chlorogenic acid, schisandra chinensis, and phospholipase would not achieve the desired effect. Experimental groups 1-3 achieved maximum degreasing by combining the adsorption of components with the chemical degradation of phospholipase, simultaneously decomposing internal fat and stripping away surface free fat. Control group 12 increased the proportion of phospholipase, and although its fat content was lower than that of control group 1, it was still higher than that of experimental groups 1-3, indicating that a higher proportion of phospholipase does not necessarily lead to better degreasing. Subsequent experiments revealed that its textural properties were lower than those of experimental groups 1-3 (see Table 5). Control group 1, which did not use any soaking agent to treat the fish glue, had the highest fat content (1.82%), indicating that this invention has a significant effect on the removal of fat from dried fish glue. In control group 3, increasing the proportion of kudzu root powder increased the fat content of the fish glue to 0.84%, presumably because excessive kudzu root powder formed a complex with the fat, increasing the difficulty of fat removal. In control group 7, acetic acid was used instead of chlorogenic acid, resulting in a significant decrease in degreasing effect, indicating that the chlorogenic acid in this invention is irreplaceable. Control group 10 showed poor degreasing effect, indicating that although the organic acids in Schisandra chinensis powder can affect fat removal, a dosage of 0.3% is insufficient to significantly remove hydrophobic fats. Experimental results show that temperature is a key factor in fat dissolution. Control group 14, by lowering the drying temperature, achieved a fat content of 1.59%; while excessively high drying temperatures (control group 13) easily cause deformation and shrinkage of collagen fibers on the surface of the fish glue, blocking the fat dissolution channels.

[0061] The results of trimethylamine content determination in each experimental group and control group are shown in Table 3.

[0062] Table 3. Trimethylamine content (μg / g) of fish glue processed by different drying methods

[0063] As shown in Table 3, the trimethylamine content was lowest in experimental groups 1-3, while the trimethylamine content was highest (15.77 μg / g) in control group 13, which was dried at high temperature. The data from control group 1 indicates that fish glue not treated with the technology of this invention had a higher trimethylamine content. The data from control groups 3 and 4 show that increasing or decreasing the amount of kudzu root powder increased the trimethylamine content compared to experimental groups 1-3, proving that kudzu root powder has an effect in reducing trimethylamine content. Adjusting the amount of Schisandra chinensis powder (control groups 8-10) revealed a certain degree of increase in trimethylamine content, indicating that Schisandra chinensis needs to be added in the specific proportions of this invention to achieve the best effect. In control group 11, without the addition of phospholipase, the trimethylamine content increased to 11.48 μg / g, indicating that phospholipase helps reduce the formation of trimethylamine. Control group 13 had the highest trimethylamine content, indicating that phospholipids in fish glue are easily decomposed to form trimethylamine during high-temperature drying or storage. Phospholipids (such as phosphatidylcholine) in fish maw are precursors to trimethylamine and other fishy-smelling substances, which easily decompose to produce trimethylamine under high-temperature conditions. Therefore, this invention reduces the content of fishy-smelling precursors at the source by hydrolyzing phospholipids with phospholipase. Comparative group 14 shows that if drying is carried out at 25-30℃, uneven drying may occur due to unstable ambient temperature or the inability to form air convection, resulting in insufficient decomposition of phospholipids or abnormal microbial metabolism, thus affecting the trimethylamine content. Comparative group 15 shows that removing the bubbling washing process may result in the residue of fat and blood, ultimately affecting the trimethylamine content in the finished product.

[0064] The collagen content of each experimental group and control group is shown in Table 4.

[0065] Table 4. Collagen content (%) of fish maw processed by different drying methods

[0066] Table 4 shows the collagen content of fish glue dried using different methods. Control group 6, with its reduced chlorogenic acid ratio, showed a lower collagen content compared to experimental groups 1-3, indicating that chlorogenic acid has a protective effect on collagen. Adjusting the content of Schisandra chinensis powder (control groups 8-10) resulted in a certain degree of decrease in collagen content, suggesting that Schisandra chinensis needs to be processed at the specific ratio described in this invention to achieve the best effect. The collagen content of control groups 13 and 14 was lower than that of experimental groups 1-3, indicating that excessively high or low drying temperatures affect the collagen content of the dried glue. Data from control group 13 suggests that using a high-temperature process to produce the dried glue reduces the collagen ratio, possibly because the high temperature damages the collagen structure.

[0067] The results of the textural properties determination for each experimental group and the control group are shown in Table 5.

[0068] Table 5. Texture properties of fish glue processed by different drying methods

[0069] Table 5 shows that the dried samples were first sterilized, followed by texture testing to simulate their actual state in subsequent production applications. The results indicate that the experimental group exhibited the best hardness, elasticity, and chewiness, while the group without any soaking solution (Control Group 1) had the worst texture. Control Group 5 shows that when the chlorogenic acid content is too low, it is difficult to effectively improve the elasticity and other texture indicators of fish glue. Control Groups 2-6 and 8-10 show that kudzu root powder, chlorogenic acid, and schisandra chinensis can produce a synergistic effect, jointly improving the softness and elasticity of fish glue. Changing the proportion of any one of these ingredients will destroy this synergistic effect, leading to impaired texture properties of the fish glue. When acetic acid was used instead of chlorogenic acid (Control Group 7) to treat the fish glue, the overall texture properties of the fish glue were poor, indicating that chlorogenic acid in this invention is irreplaceable. Control Groups 11-12 show that the texture properties of the group with increased phospholipase ratio (Control Group 12) decreased, indicating that the phospholipase ratio needs to be controlled within the range of this invention. Comparative group 13 showed that increasing the drying temperature would damage the fish collagen texture, possibly because high temperatures accelerate protein denaturation and disrupt the three-dimensional structure of collagen. In comparative group 14 (lower drying temperature), residues of blood stains, glue oil, and other substances could easily result in the fish collagen surface drying completely but the interior not drying in time, affecting the uniformity of the fish collagen texture.

[0070] The microstructure of fish maw from different groups was observed using a scanning electron microscope at 500x magnification. The results are as follows: Figure 2 As shown. From Figure 2 It can be seen that experimental group 2 presents a relatively regular network structure; control group 6 (reduced chlorogenic acid ratio) presents a network structure, but it is not uniform and flat; control group 5 (increased chlorogenic acid ratio) shows obvious voids; control group 11 (no phospholipase added) shows a relatively loose sheet-like microstructure; control group 12 (increased phospholipase ratio) shows more voids and gaps.

[0071] The actual appearance of fish maw obtained by different drying methods is as follows: Figure 3 As shown. By Figure 3 It is evident that the fish maw in experimental group 2 is in the best condition, with uniform color, no bloodstains, and no floating oil. The control group 1 (without any reagents) still shows a blood-red color after drying. The finished product colors of control group 2 (without kudzu root powder), control group 6 (with reduced chlorogenic acid ratio), and control group 8 (without schisandra powder) are all affected to varying degrees. The fish maw head of control group 11 (without phospholipase) shows obvious oil residue, which will affect the flavor of subsequent fish maw products and thus affect consumer acceptance.

[0072] In summary, the dried fish glue production method provided by this invention can efficiently remove fat and blood from fish glue, significantly reduce fishy smell, and at the same time retain the collagen content and good texture of fish glue to the greatest extent. The product has uniform color, no floating oil, and good elasticity.

[0073] The above description is merely a preferred embodiment of this application and an explanation of the technical principles employed. Those skilled in the art should understand that the scope of the invention involved in this application is not limited to technical solutions formed by specific combinations of the above-described technical features, but should also cover other technical solutions formed by arbitrary combinations of the above-described technical features or their equivalents without departing from the above-described inventive concept. For example, technical solutions formed by substituting the above features with (but not limited to) technical features with similar functions disclosed in this application.

Claims

1. A method for producing dried fish glue, characterized in that, Includes the following steps: S1. Add fresh fish maw to the soaking tank and soak it in the first soaking solution at a temperature below 25°C for 1 hour. The first soaking solution consists of 0.2% chlorogenic acid, 0.1%-0.3% kudzu root powder, and the remainder water by mass percentage. After soaking, start the micro-nano bubbling ozone cleaner for bubbling cleaning for 15 minutes, controlling the ozone concentration to 0.5-0.8 ppm, to obtain fish maw after one cleaning. S2. The fish glue after the first cleaning is fed into an extruder and extruded at a speed of 3-8 m / min under a pressure of 0.3-0.8 MPa to obtain the extruded fish glue. S3. First, add the extruded fish glue to the second soaking solution and soak it at below 25°C for 1 hour. The second soaking solution consists of 0.5%-2% Schisandra chinensis powder and the remainder water by mass percentage. After removing the fish glue, obtain the fish glue soaked in Schisandra chinensis. Then, add the fish glue soaked in Schisandra chinensis to the third soaking solution and soak it at below 25°C for 1 hour. The third soaking solution consists of 0.01%-0.03% phospholipase and the remainder water by mass percentage. Obtain the fish glue after secondary cleaning. S4. Add the fish maw after the second cleaning to water below 25℃ and rinse manually for 30 minutes to obtain the rinsed fish maw. S5. The rinsed fish maw is sun-dried at 30-35℃ for 12 hours to obtain sun-dried fish maw. S6. The dried fish maw is fed into a fish maw roller brush cleaning machine for roller brush cleaning to obtain fish maw after roller brush cleaning; the operating conditions for roller brush cleaning are: roller brush speed 20-60 r / min, conveying speed 3-8 m / min, spraying pressure 0.1-0.3 MPa; the brush bristles used in the fish maw roller brush cleaning machine are soft brush bristles. S7. Place the fish glue cleaned by the roller brush into a spin dryer to spin dry, and obtain the spin-dried fish glue. S8. Place the spun-dry fish glue on a ventilation rack and dry it in air circulation at 35-40℃ for 48-72 hours to obtain dried fish glue.

2. The method for preparing dried fish glue according to claim 1, characterized in that, In step S1, the mass percentage of kudzu root powder in the first soaking solution is 0.2%.

3. The method for preparing dried fish glue according to claim 1, characterized in that, In step S3, the mass percentage of Schisandra chinensis powder in the second soaking solution is 1%.

4. The method for preparing dried fish glue according to claim 1, characterized in that, The mass percentage of phospholipase in the third soaking solution described in step S3 is 0.02%.

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