Method for removing fishy smell of liver and fishy smell removed liver powder

Abstract

The invention discloses a liver fishy smell removing method and fishy smell removed liver powder. According to the method, the liver raw materials are subjected to pure physical treatment such as crushing, slow quick-freezing and melting, short-time heating and centrifuging, so that the fishy smell of the livers of the livestock is effectively removed. By utilizing the liver fishy smell removing method, the fishy smell removed liver powder which does not contain any chemical additive and chemical residue is also prepared, and the fishy smell removed liver powder can be used as a food processing raw material for subsequent deep processing and can be prepared into products such as liver paste and the like. Compared with liver raw materials which are not deodorized, volatile fishy smell substances in the deodorized liver powder prepared by the method disclosed by the invention are remarkably reduced, the fishy smell value is greatly reduced, and the fishy smell removal effect is good. The fishy smell removing method can effectively remove the fishy smell in the livers, high-value utilization of the livers of the livestock is facilitated, the operation is simple, and the prepared poultry liver powder belongs to green and natural food materials.

Description

Technical Field

[0001] The present invention belongs to the technical field of food processing, and more specifically relates to a method for removing fishy smell from liver and fishy smell-removed liver powder. Background Art

[0002] The liver is a vital internal organ of livestock and poultry, rich in nutrients such as protein, unsaturated fatty acids, vitamins, and minerals. However, the strong fishy odor commonly found in livers from various sources hinders the full utilization of this nutrient-rich livestock slaughter and processing byproduct, resulting in low processing efficiency and added value. Therefore, there is an urgent need to develop safe and efficient methods for removing the fishy odor to improve the meat processing industry chain and promote the high-value utilization of livestock and poultry livers.

[0003] Fresh liver has no discernible fishy odor. However, when removed from the body and exposed to oxygen and microbial environments, protein breakdown and lipid oxidation produce organic compounds such as amines, alcohols, aldehydes, ketones, low-molecular acids, and sulfides, which are the main components of liver's fishy odor. To remove the fishy odor from liver, a range of methods have been developed. Existing liver deodorization methods mainly fall into three categories: physical, chemical, and biological. Physical methods include adsorption, sensory masking, and encapsulation / microencapsulation. Chemical methods include acid-base-salt treatment, antioxidants, and the Maillard reaction. Biological deodorization primarily uses fermentation to reduce liver's fishy odor.

[0004] Adsorption deodorization primarily utilizes the porous structure of the adsorbent to trap fishy substances flowing through the adsorbent on its surface or within the adsorbent, producing a deodorizing effect. This method has the advantages of simple operation and strong adsorption capacity, but other nutrients may be trapped during the adsorption process, resulting in a reduction in nutritional value, and its application is limited to highly fluid liquid states. Sensory masking is the most primitive deodorization method, with good deodorization effects. Its advantages are simplicity, directness, and time efficiency, making it suitable for use in cooking processes. While masking the fishy smell of liver, it also creates a new flavor. However, this method is not suitable for industrial liver powder deodorization. Encapsulation deodorization utilizes β-cyclodextrin to encapsulate small molecules in the liver, resulting in poor deodorization effects. Furthermore, the poor solubility of β-cyclodextrin hinders the subsequent utilization of liver pulp (powder).

[0005] Chemical deodorization primarily involves direct reactions between chemical reagents such as acids, bases, salts, natural antioxidants, oxidants, and reducing sugars and odor-removing substances. Compared to physical deodorization, the most prominent drawback of chemical deodorization is the tendency to create chemical residues, posing a potential food safety hazard. Biological deodorization primarily relies on microbial metabolism or enzymes to convert odorous substances into odorless substances. Yeast fermentation is the most commonly used biological deodorization method, but this method is time-consuming, prone to contamination by other microorganisms, and has poor and unstable deodorization results.

[0006] In summary, there is still a lack of safe and efficient methods for removing the fishy smell from liver, and thus a method for preparing a fishy-removed liver product that does not contain any chemical additives or chemical residues. Summary of the Invention

[0007] In view of the deficiencies in the prior art, the present invention provides a method for removing fishy smell from liver and fishy smell-removed liver powder.

[0008] The first object of the present invention is to provide a method for removing the fishy smell of liver.

[0009] The second object of the present invention is to provide a method for preparing deodorized liver powder.

[0010] The third object of the present invention is to provide a deodorized liver powder.

[0011] The above-mentioned purpose of the present invention is achieved through the following technical solutions: Through exploration, the present invention has developed a purely physical liver deodorization method that can effectively remove the fishy odor of liver. Based on the method described in the present invention, the present invention also produces a deodorized liver powder that can be used as a food processing raw material for subsequent deep processing, achieving high-value utilization of the liver. Therefore, the present invention seeks protection for the liver deodorization method.

[0012] Specifically, the liver deodorization method of the present invention comprises the following steps: S1. Add water to the cleaned liver and prepare a liver homogenate in a manner that disrupts the liver lobule structure. S2. Freeze the liver homogenate obtained in S1 at -10°C to 20°C until the center temperature of the homogenate is -4°C to 8°C, and then thaw at 4°C to 10°C. S3. Heat the thawed liver homogenate in S2 to 62°C to 78°C, maintain for 1 to 20 minutes, and then remove water from the liver homogenate by standing, filtering and / or centrifuging to obtain deodorized liver slurry, thereby completing liver deodorization.

[0013] Specifically, in S1, the cleaned liver is a liver that has been cleaned after the gallbladder, solid fat and connective tissue are removed.

[0014] Specifically, the liver is poultry liver.

[0015] More specifically, the poultry and livestock liver is fresh poultry and livestock liver or thawed poultry and livestock liver.

[0016] Specifically, the thawing temperature of the thawed poultry and livestock liver is 4°C to 6°C.

[0017] Specifically, the poultry liver includes chicken liver, duck liver, and goose liver.

[0018] Specifically, in S1, water 0.5 to 2.5 times the mass of the liver is added to prepare a liver homogenate.

[0019] More specifically, in S1, water 1 to 2 times the mass of the liver is added to prepare liver homogenate.

[0020] Specifically, in S1, the liver is cut into strips and then prepared into a liver homogenate.

[0021] Specifically, in S1, the liver is prepared into liver homogenate using a high-speed blender or a homogenizer.

[0022] Specifically, in S1, intermittent homogenization was performed at 2000-4000 r / min for 1-2 min to obtain liver homogenate.

[0023] More specifically, in S1, the intermittent homogenization is started for 30 s and stopped for 10 s.

[0024] Specifically, in S2, the obtained liver homogenate is frozen at -12°C to -18°C until the center temperature of the homogenate is -5°C to -8°C, and then thawed at 4°C to 6°C.

[0025] Specifically, the thawed liver homogenate is fully stirred and then heated in a water bath.

[0026] Preferably, the pH of the thawed liver homogenate is adjusted to 6.8-7.2 with sodium bicarbonate, and then heated after being fully stirred.

[0027] More specifically, the pH was adjusted with 3% food grade sodium bicarbonate.

[0028] Specifically, in S3, the thawed liver homogenate is heated to 62°C to 78°C and maintained for 1 to 10 minutes.

[0029] Specifically, in S3, the thawed liver homogenate is heated to 65°C to 75°C and maintained for 1 to 5 minutes.

[0030] Specifically, in S3, the thawed liver homogenate is heated by water bath heating or direct heating.

[0031] Preferably, in S3, water is removed from the liver homogenate by centrifugation. Compared with dehydration methods such as filter press, centrifugation can increase the fishy smell removal rate by 20% to 30%.

[0032] Specifically, the centrifugation conditions are: 3000-4000 r / min for 15-20 min.

[0033] Preferably, in S3, after removing water from the liver homogenate by centrifugation, water is added to wash the precipitate obtained by centrifugation, and then water is removed by centrifugation or filtration. Adding this process can improve the deodorization effect.

[0034] Specifically, wash 1 to 2 times.

[0035] The invention also provides a method for preparing the deodorized liver powder.

[0036] Specifically, the preparation method comprises the following steps: after deodorizing the liver using the liver deodorizing method, drying the deodorized liver pulp to obtain deodorized liver powder.

[0037] Optionally, the deodorized liver powder is prepared by hot air drying, freeze drying or spray drying.

[0038] Specifically, the moisture content of the deodorizing dry powder is 8% to 12%.

[0039] More specifically, the moisture content of the deodorizing dry powder is 10±1%.

[0040] Specifically, the hot air drying temperature is 50°C to 100°C.

[0041] In a specific embodiment of the present invention, the method for preparing deodorized liver powder by hot air drying is as follows: drying the deodorized liver pulp at 95±1°C to a moisture content of 40±2%, stirring during the process to prevent agglomeration; cooling to 75±1°C and drying for 1 hour, and then drying at 50±1°C to a moisture content of 10±1% to obtain deodorized liver powder.

[0042] In a specific embodiment of the present invention, the method for preparing the deodorized dry powder by freeze drying is as follows: the deodorized liver pulp is placed in a -45±℃ freezer for pre-freezing, transferred to a vacuum freeze dryer, and dried at 10 Pa to 20 Pa until the moisture content is less than 10%, thereby obtaining the deodorized liver powder.

[0043] The present invention also provides deodorized liver powder prepared by the preparation method.

[0044] Specifically, the deodorized liver powder is deodorized poultry liver powder.

[0045] The present invention has the following beneficial effects: The present invention provides a method for removing fishy smell from liver, which achieves effective removal of the fishy smell of livestock and poultry livers by subjecting the liver raw material to pure physical treatments such as crushing, slow freezing and thawing, short-time heating and centrifugation. Utilizing the liver deodorization method, the present invention also prepares deodorized liver powder that does not contain any chemical additives and chemical residues, which can be used as a food processing raw material for subsequent deep processing to produce products such as liver paste. Compared with liver raw materials that have not been deodorized, the deodorized liver powder prepared by the method of the present invention contains significantly fewer volatile fishy substances, the fishy value is greatly reduced, and the deodorization effect is good. That is, the deodorization method of the present invention can effectively remove the fishy smell from the liver, is conducive to the high-value utilization of livestock and poultry livers, is simple to operate, and the deodorized poultry liver powder prepared is a green and natural food ingredient. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 The radar chart of the response values ​​of the deodorized chicken liver powder and the control chicken liver powder prepared in Example 1; p <0.05.

[0047] Figure 2 This is the PCA diagram of the deodorized chicken liver powder and the control chicken liver powder prepared in Example 1.

[0048] Figure 3 This is a radar chart of the response values ​​of the deodorized duck liver powder and the control duck liver powder prepared in Example 2; p <0.05.

[0049] Figure 4 This is the PCA diagram of the deodorized duck liver powder and the control duck liver powder prepared in Example 2.

[0050] Figure 5 This is a radar chart of the response values ​​of the deodorized goose liver powder and the control goose liver powder prepared in Example 3; p <0.05.

[0051] Figure 6 This is the PCA diagram of the deodorized goose liver powder and the control goose liver powder prepared in Example 3. DETAILED DESCRIPTION

[0052] The present invention will be further described below with reference to the accompanying drawings and specific examples, but the examples do not limit the present invention in any way. Unless otherwise specified, the reagents, methods and equipment used in the present invention are conventional reagents, methods and equipment in the art.

[0053] Unless otherwise specified, the reagents and materials used in the following examples were commercially available.

[0054] Example 1 Preparation of Deodorized Chicken Liver Powder 1. Preparation of deodorized chicken liver powder The preparation of the deodorized chicken liver powder comprises the following steps: S1. Take fresh chicken liver, remove the gallbladder, solid fat, connective tissue, and other debris, wash it, and cut it into slices or strips. Add 1.5 times the mass of the liver in water and stir at 2000 rpm for 2 minutes with an intermittent stirring interval (30 seconds on, 10 seconds off) to obtain a liver homogenate. S2. Pour the resulting liver homogenate into a freezing tray and slowly freeze at -15°C until the core temperature of the liver homogenate reaches -6°C. Thaw the mixture at 4°C. S3. Heat the thawed liver homogenate to 70°C in a water bath, maintain this temperature for 1.5 minutes, and then centrifuge at 3000 rpm for 15 minutes. Discard the supernatant to obtain the deodorized liver slurry. S4. Pour the obtained deodorized liver pulp into a 304 stainless steel tray and place it in a dryer; dry it at 95°C to a moisture content of 40±2%, turning it over during the process to prevent agglomeration; cool it to 75°C and dry it for 1 hour, then transfer it to 50°C and dry it to a moisture content of 10±1% to obtain deodorized chicken liver powder.

[0055] 2. Deodorization effect test To test the liver deodorization efficacy of the present invention, the deodorized chicken liver powder prepared was used as the test sample. Electronic nose analysis of the deodorized chicken liver powder and a control chicken liver powder was performed to detect changes in volatile odorous compounds and evaluate the fishy odor. The control chicken liver powder was prepared by removing impurities such as the gallbladder, solid fat, and connective tissue, washing, and cutting into strips. The liver was then mixed with 1.5 times its weight of water and stirred intermittently at 2000 rpm for 2 minutes (30 seconds on, 10 seconds off) to obtain a control chicken liver homogenate. The homogenate was poured into a 304 stainless steel dish and placed in a dryer. Drying was performed at 95°C to a moisture content of 40±2%, stirring the dish to prevent clumping. The mixture was then cooled to 75°C and dried for an additional hour. The mixture was then dried at 50°C to a moisture content of 10±1%, yielding the control chicken liver powder.

[0056] The instrument used for electronic nose analysis in the present invention is a PEN3 electronic nose sensor, and its analyzed component categories are W1C (aromatic components, benzene), W5S (nitrogen oxides), W3C (aromatic components, ammonia), W6S (hydrides), W5C (short-chain alkane aromatic components), W1S (methyls), W1W (sulfides), W2S (alcohols, aldehydes, ketones), W2W (aromatic components, organic sulfides) and W3S (long-chain alkanes). The electronic nose analysis method was carried out according to the method described in the literature (Liu Zeqi et al. Effects of different deodorization methods on chicken liver flavor substances [J]. Food Industry Science and Technology, 2022, 43(13): 258-266). 10.0 g of sample was taken in a 30 mL headspace bottle and heated to (25±2)°C for detection. The electronic nose conditions were as follows: clean air as carrier gas, internal flow rate of 400 mL / min, injection flow rate of 400 mL / min, sample analysis time of 100 s, sensor cleaning time of 60 s, and zeroing time of 10 s. Each sample was measured in parallel three times. Based on the electronic nose analysis results, a radar chart of the response values ​​of the obtained deodorized chicken liver powder and the control chicken liver powder was drawn, and the significance analysis of the response values ​​of the analyzed components was performed. At the same time, the present invention also performed PCA analysis on the obtained deodorized chicken liver powder and the control chicken liver powder based on the electronic nose analysis results and drew a PCA chart. The fishy smell evaluation method was also carried out according to the method described in the literature (Liu Zeqi et al. Effects of different deodorization methods on chicken liver flavor substances [J]. Food Industry Science and Technology, 2022, 43(13): 258-266.) to obtain the corresponding fishy smell value.

[0057] The response value radar chart of the deodorized chicken liver powder and the control chicken liver powder prepared in this example is as follows Figure 1 As shown. Figure 1 It can be seen that the response values ​​of W1S and W3S in the obtained deodorized chicken liver powder are significantly different from those of the control chicken liver powder ( p <0.05). The PCA diagram of the prepared deodorized chicken liver powder and the control chicken liver powder is shown in Figure 2. Figure 2 As shown. Figure 2 It can be seen that the flavor of the prepared deodorized chicken liver powder and the control chicken liver powder is significantly different. The deodorized chicken liver powder prepared in this example has a fishy odor value of 0.50 points, while the fishy odor value of the control chicken liver powder is 4.00 points.

[0058] The above results show that the liver fishy smell removal method of the present invention can effectively remove the fishy smell of chicken liver.

[0059] Example 2 Preparation of Deodorized Duck Liver Powder Based on the preparation method of the deodorized chicken liver powder and the control chicken liver powder described in Example 1, the present invention replaces the chicken liver with duck liver to prepare deodorized duck liver powder and the control duck liver powder, and uses the same method to test their deodorizing effects.

[0060] Using duck liver as raw material, after being treated by the liver deodorization method of the present invention, the deodorized duck liver powder prepared has a fishy smell value of 0.13 points, while the fishy smell value of the control duck liver powder is 4.50 points. The response value radar chart of the deodorized duck liver powder prepared in this example and the control duck liver powder is as follows Figure 3 As shown. Figure 3 It can be seen that the response values ​​of W6S, W1S, W2S and W3S in the deodorized duck liver powder prepared in this example are significantly different from those of the control duck liver powder ( p <0.05). The PCA diagram of the deodorized duck liver powder prepared in this example and the control duck liver powder is shown in Figure 2. Figure 4 As shown. Figure 4 It can be seen that the flavor of the prepared deodorized duck liver powder and the control duck liver powder is significantly different.

[0061] The above results show that the liver fishy smell removal method of the present invention can effectively remove the fishy smell of duck liver.

[0062] Example 3 Preparation of deodorized goose liver powder Based on the preparation method of the deodorized chicken liver powder and the control chicken liver powder described in Example 1, the present invention replaces chicken liver with goose liver to prepare deodorized goose liver powder and the control goose liver powder, and uses the same method to test their deodorizing effects.

[0063] Using goose liver as raw material, after being treated by the liver deodorization method of the present invention, the deodorized goose liver powder prepared has a fishy smell value of 0.50 points, while the fishy smell value of the control chicken liver powder is 4.00 points. The response value radar chart of the deodorized goose liver powder prepared in this example and the control goose liver powder is as follows Figure 5 As shown. Figure 5 It can be seen that the response values ​​of W1S, W2S and W3S in the prepared deodorized goose liver powder were significantly different from those of the control goose liver powder ( p <0.05). The PCA diagram of the deodorized goose liver powder prepared in this example and the control goose liver powder is shown in Figure 2. Figure 6 As shown. Figure 6 It can be seen that the flavor of the prepared deodorized goose liver powder and the control goose liver powder is significantly different.

[0064] The above results show that the liver fishy smell removal method of the present invention can effectively remove the fishy smell of goose liver.

[0065] Example 4 Preparation of Deodorized Chicken Liver Powder Based on the preparation method of the deodorized chicken liver powder described in Example 1, the present invention prepares the deodorized chicken liver powder using frozen chicken liver as raw material.

[0066] The preparation of the deodorized chicken liver powder comprises the following steps: S1. Thaw frozen chicken liver in running water at 15°C. Remove the gallbladder, solid fat, connective tissue, and other debris after thawing. Rinse and cut into slices or strips. Add water twice the mass of the liver and stir at 2000 rpm for 2 minutes with an intermittent stirring cycle (30 seconds on, 10 seconds off) to obtain a liver homogenate. S2. Pour the resulting liver homogenate into a freezer tray and slowly freeze at -18°C until the core temperature of the liver homogenate reaches -8°C. Thaw the homogenate at 4°C, adjust the pH to 7.0 with 3% sodium bicarbonate, and stir thoroughly. S3. Heat the thawed liver homogenate to 65°C, maintain this temperature for 5 minutes, and then centrifuge at 3000 rpm for 15 minutes. Discard the supernatant. Add an equal amount of purified water to the precipitate for washing. Mix thoroughly and centrifuge at 2000 rpm for 15 minutes. Discard the supernatant to obtain the deodorized liver slurry. S4. Pre-freeze the obtained deodorized liver pulp in a -45°C freezer, transfer it to a vacuum freeze dryer, and freeze-dry it at 10-20 Pa for 10 hours until the moisture content is less than 10%, thereby obtaining deodorized chicken liver powder.

[0067] The fishy smell value of the deodorized chicken liver powder prepared in this example is the same as that of the deodorized chicken liver powder prepared in Example 1, indicating that there is no significant difference in the deodorizing effect.

[0068] Example 5 Preparation of Deodorized Chicken Liver Powder The preparation of the deodorized chicken liver powder of this embodiment comprises the following steps: S1. Take fresh chicken liver, remove the gallbladder, solid fat, connective tissue, and other debris, wash it, and cut it into slices or strips. Add water (1 times the mass of the liver) and stir at 2000 rpm for 2 minutes with an intermittent stirring interval (30 seconds on, 10 seconds off) to obtain a liver homogenate. S2. Pour the resulting liver homogenate into a freezing tray and slowly freeze at -12°C until the center temperature of the liver homogenate reaches -5°C. Thaw the mixture at 4°C. S3. Heat the thawed liver homogenate to 75°C, maintain this temperature for 2 minutes, and then centrifuge at 3500 rpm for 10 minutes. Discard the supernatant to obtain the deodorized liver slurry. S4. Pour the obtained deodorized liver pulp into a 304 stainless steel tray and place it in a dryer; dry it at 95°C to a moisture content of 40±2%, turning it over during the process to prevent agglomeration; cool it to 75°C and dry it for 1 hour, then transfer it to 50°C and dry it to a moisture content of 10±1% to obtain deodorized chicken liver powder.

[0069] The fishy smell value of the deodorized chicken liver powder prepared in this example is the same as that of the deodorized chicken liver powder prepared in Example 1, indicating that there is no significant difference in the deodorizing effect.

[0070] Comparative Example 1 Effect of Freezing Method on Deodorization Effect The preparation method of the deodorized chicken liver powder described in this comparative example is basically the same as that in Example 1, except that: in S2, after the liver homogenate is obtained, it is not placed at minus 10°C to 20°C for slow freezing, but is quickly frozen at minus 35°C. After freezing to the center temperature of the liver homogenate to -10°C, the subsequent operation steps are carried out according to the method described in Example 1.

[0071] In order to evaluate the deodorization effect, the present invention combines the fishy smell value evaluation result and the protein score in the supernatant for comprehensive scoring, obtains a comprehensive score and calculates the deodorization rate. Among them, the fishy smell value is obtained in the same way as in Example 1, and the protein score in the supernatant needs to be obtained based on the protein content in the supernatant. When the protein content in the supernatant is ≤20 μg / mL, the score is 0.1, and when the protein content in the supernatant is >20 μg / mL and ≤200 μg / mL, the score is 1.0, and so on with 10 times the amount. The method for detecting the protein content in the supernatant is as follows: take the supernatant obtained by centrifugation in the deodorized liver powder preparation process S3, and make it 10 times the wet weight of the poultry liver used in S1. For example, after 10 g of liver is treated accordingly, the resulting supernatant is made 100 mL, and the protein content is detected by the bicinchoninic acid method.

[0072] Comprehensive score = fishy smell value - protein score in supernatant; Deodorization rate = (comprehensive score of samples without deodorization - comprehensive score of samples after deodorization) / comprehensive score of samples without deodorization × 100%; Among them, the control sample was not washed and had no supernatant protein data, and the comprehensive score was the fishy smell value.

[0073] After calculation, the comprehensive score of the deodorized chicken liver powder prepared in this comparative example was 0.72 points, and the comprehensive score of the non-deodorized chicken liver powder was 4.5 points. The calculated deodorization rate was 84%.

[0074] Deodorization rate = [4.5-(1.0-0.28)] / 4.5 × 100% = 84% Using the same calculation method, the deodorized chicken liver powder prepared using the method described in Example 1 had a comprehensive score of 0.45 points, and a deodorization rate of 88.75%. By comparison, the deodorization rate decreased by 4.75% using the quick freezing method, indicating that slow freezing is more conducive to deodorizing poultry liver.

[0075] Comparative Example 2 Effect of slow freeze-thaw times on deodorization effect The preparation method of the deodorized chicken liver powder in this comparative example is basically the same as that in Example 1, except that: in S2, the liver homogenate is frozen and thawed again after being thawed, and the freezing and thawing is repeated three times.

[0076] The comprehensive score and fishy removal rate were calculated using the same method as in Comparative Example 1.

[0077] Y=[4.5-(1.0-0.6)] / 4.5 ×100% = 91.11% Calculations showed that the deodorized chicken liver powder prepared in this comparative example had an overall score of 0.4, with a deodorization rate of 91.11%. The results indicate that increasing the number of slow freeze-thaw cycles can improve the deodorization rate, but adding this step also increases process time, equipment usage, and energy consumption, so these factors should be considered comprehensively when using the product.

[0078] Comparative Example 3 Effect of heating temperature on deodorization effect The preparation method of the deodorized goose liver powder in this comparative example is basically the same as that in Example 3, except that: in S3, the thawed liver homogenate is heated to 50° C. and maintained at 5 min.

[0079] The comprehensive score and fishy removal rate were calculated using the same method as in Comparative Example 1.

[0080] Y=[4.0 - (2.0 - 0.1)] / 4.0 ×100% = 52.25% The deodorized goose liver powder prepared in this comparative example had a comprehensive score of 1.9 points and a deodorization rate of 52.25%. The results showed that, compared with the deodorized goose liver powder prepared in Example 3, lowering the heating temperature of the poultry liver pulp significantly affected the deodorization effect.

[0081] Comparative Example 4 Effect of heating temperature on deodorization effect The preparation method of the deodorized chicken liver powder in this comparative example is basically the same as that in Example 1, except that: in S3, the thawed liver homogenate is heated to 80° C. and maintained for 5 min.

[0082] The comprehensive score and fishy removal rate were calculated using the same method as in Comparative Example 1.

[0083] Y=[4.0-(1.5-0.15)] / 4.0 ×100% = 66.25% Calculations revealed that the deodorized chicken liver powder prepared in this comparative example had an overall score of 1.35, with a deodorization rate of 66.25%. The results indicate that increasing the heating temperature of the poultry liver homogenate significantly impacted deodorization compared to the deodorized chicken liver powder prepared in Example 1. This may be due to the denaturation and precipitation of the target substance during the 5-minute heating of the liver homogenate at 80°C, which compromised deodorization.

[0084] Comparative Example 5 Effect of Filtration Method on Deodorization Effect The preparation method of the deodorized chicken liver powder in this comparative example is basically the same as that in Example 1, except that the supernatant of the heated liver homogenate is removed by pressure-free filtration.

[0085] The comprehensive score and fishy removal rate were calculated using the same method as in Comparative Example 1.

[0086] Y=[4.5-(2.0-0.06)] / 4.5 ×100% = 56.89% Calculations showed that the deodorized chicken liver powder prepared in this comparative example had a comprehensive score of 1.94 points, with a deodorization rate of 56.89%. Compared to the deodorized chicken liver powder prepared in Example 1 (88.75%), this rate decreased by 32%, indicating that the pressureless filter paper filtration method is not conducive to removing odorous substances.

[0087] Comparative Example 6 Effect of Increasing the Number of Washes on the Deodorization of Liver Pulp The preparation method of the deodorized duck liver powder described in this comparative example is basically the same as that in Example 2, except that: the thawed liver homogenate is heated to 70°C in a water bath, maintained for 5 minutes, centrifuged at 3000 r / min for 15 minutes, and the supernatant is discarded; 1 times the mass of pure water is added to the precipitate again, centrifuged at 3000 r / min for 15 minutes, and the supernatant is discarded to obtain the deodorized liver pulp.

[0088] The comprehensive score and fishy removal rate were calculated using the same method as in Comparative Example 1.

[0089] Y=[4.5-(1.0-0.4)] / 4.5 ×100% = 86.67% Calculations showed that the deodorized duck liver powder prepared in this comparative example had a comprehensive score of 0.6 points, with a deodorization rate of 86.67%. Compared with the deodorized duck liver powder prepared in Example 2, the deodorization rate increased by 4.45% from 82.22% in Example 2, indicating that adding washing and centrifugation can improve the deodorization effect. However, adding these steps also increases the process time, equipment usage, and energy consumption.

[0090] Comparative Example 7 Effect of Drying Method on Deodorizing Powder The preparation method of the deodorized goose liver powder described in this comparative example is basically the same as that in Example 3, except that: the thawed liver homogenate is heated to 70°C in a water bath for 5 minutes, centrifuged at 3000 r / min for 15 minutes, and the supernatant is discarded to obtain the deodorized liver slurry and spray-dried; the inlet air temperature of the spray drying is 180±2°C, and the outlet air temperature is 85±2°C.

[0091] The comprehensive score and fishy removal rate were calculated using the same method as in Comparative Example 1.

[0092] Y=[4.0-(0.5-0.12)] / 4.0 ×100% = 90.5% After calculation, the comprehensive score of the deodorized goose liver powder prepared in this comparative example was 0.38 points, and the deodorization rate was 90.5%, which was not significantly different from the deodorized goose liver powder prepared in Example 3, indicating that after the fishy substances were removed, the drying method did not affect the flavor of the deodorized dry powder.

[0093] The above embodiments are preferred implementation modes of the present invention, but the implementation modes of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present invention should be considered as equivalent replacement methods and are included in the scope of protection of the present invention.

Claims

1. A method for removing fishy smell from liver, characterized in that: The following steps are involved: S1. Add water to the cleaned liver and prepare a liver homogenate in a manner that disrupts the liver lobule structure. S2. Freeze the liver homogenate obtained in S1 at -10°C to 20°C until the center temperature of the homogenate is -4°C to 8°C, and then thaw at 4°C to 10°C. S3. Heat the thawed liver homogenate in S2 to 62°C to 78°C, maintain for 1 to 20 minutes, and then remove water from the liver homogenate by standing, filtering and / or centrifuging to obtain deodorized liver slurry, thereby completing liver deodorization.

2. The method according to claim 1, characterized in that In S1, the liver is prepared into liver homogenate using a high-speed blender or a homogenizer.

3. The method according to claim 1, characterized in that In S2, the obtained liver homogenate is frozen at -12°C to -18°C until the center temperature of the homogenate is -5°C to -8°C.

4. The method according to claim 1, characterized in that In S3, before heating the thawed liver homogenate, the pH of the thawed liver homogenate is adjusted to 6.8-7.2 using sodium bicarbonate.

5. The method according to claim 1, characterized in that: In S3, after removing water from the liver homogenate, water of the same mass as the precipitate is added for washing, and the water in the liver homogenate is removed again by standing, filter pressing and / or centrifugation.

6. The method according to claim 1, characterized in that In S3, the thawed liver homogenate is heated to 65°C to 75°C and maintained for 1 to 10 minutes.

7. A method for preparing deodorized liver powder, characterized in that: After the liver is deodorized by the method according to any one of claims 1 to 6, the deodorized liver pulp is dried to obtain deodorized liver powder.

8. The preparation method according to claim 7, characterized in that: The deodorized liver powder is obtained by hot air drying, freeze drying or spray drying.

9. The preparation method according to claim 8, characterized in that: The moisture content of the deodorizing dry powder is 8% to 12%.

10. Deodorized liver powder prepared by the method according to any one of claims 7 to 9.

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