Method for improving digestibility of blood powder

Abstract

The invention belongs to the technical field of feed, and particularly relates to a method for improving blood powder digestibility, which comprises the following process steps: blood collection: during blood collection, adding 0.5-10kg of anticoagulant into each ton of fresh blood, so that the blood is not caked during collection; hair, excrement and other impurities are filtered through a screen, and it is guaranteed that blood is pure and good in mobility; cooking: putting the blood into a cooking pot with a stirrer, cooking for a certain time at a certain temperature, stopping cooking until the blood is completely solidified, and cooling; filter pressing: extruding the cooked blood by using extrusion equipment to filter water so as to obtain a filter cake; crushing: crushing the extruded filter cake by using a crusher to obtain semi-dry wet powder; and drying: feeding the crushed semi-dry wet powder into a flash drying tower or other drying equipment, such as a roller drying device, and drying to obtain the blood powder. The method provided by the invention can effectively improve the utilization value of the blood powder and improve the digestion and absorption rate.

Description

Technical Field

[0001] The invention belongs to the technical field of feed, and in particular relates to a method for improving the digestibility of blood meal. Background Art

[0002] Blood meal is an unconventional animal-derived feed. Blood meal can be used as a protein supplement in feeds such as pet food and aquatic feed. Since blood meal has high nutritional value, it has considerable application prospects in the field of feed. In the prior art, the processing methods of blood meal generally include physical method, cooking method, puffing method, enzymatic method and the like.

[0003] The cooking method is a commonly used processing method in the prior art. The basic steps include: allowing the blood to naturally coagulate into blood clots, collecting the blood clots, cooking, pressurizing and filtering the water, drying naturally or drum drying or drying with flash evaporation equipment. This operation does not fundamentally solve the problem of the digestibility of blood meal, but only collects and dries the blood to make a finished product.

[0004] A blood meal processing method is also disclosed in the prior art, which includes adding a certain amount of salt to fresh blood for stirring to allow the blood to coagulate into blocks, and then boiling at 50-60 degrees Celsius, squeezing and filtering the water after boiling, and drying. To ensure the shelf life, a certain amount of quicklime is also added to the fresh blood. However, the blood meal processing method in the above technology does not improve the digestibility of the blood meal, and the processed blood meal has the disadvantage of low digestibility. Moreover, the blood meal processing method in the technology also requires adding quicklime to the blood. Because the purity of quicklime is not enough, it contains a lot of un-powdered stone impurities, which will remain in the blood meal, thereby reducing the quality of the blood meal and destroying the original nutrients in the blood.

[0005] The main reasons for the low digestibility of blood meal are as follows: 1. After the blood flows out and contacts the air, under the action of calcium and magnesium ions and thrombin, the fibrinogen in the blood quickly coagulates into fibrin. The fibrin presents a three-dimensional network structure, which wraps up all nutrients such as red blood cells, white blood cells, globulin and albumin in the blood, which is the blood clot visible to the naked eye. This blood clot is formed by the wrapping of fibrin, which is not easy to digest. When feeding animals, the nutrients wrapped by it cannot be well released and digested and utilized, but are directly excreted from the body, affecting the digestion and absorption of blood meal and causing great waste.

[0006] 2. Blood contains various nutrients and is a breeding ground for microorganisms and bacteria. It is easily used by microorganisms to reproduce and cause blood corruption. Corrupted blood has a high content of amino acid nitrogen and contains a large amount of histamine and cadaverine, which can cause great damage to the animal's intestines. In order to ensure healthy breeding and fully utilize the nutritional value of blood, intervention is needed.

[0007] 3. If the processing temperature is too high or the high temperature lasts too long, the protein structure will denature. This denaturation is not conducive to the digestion and utilization of protein by digestive enzymes, resulting in low protein digestibility, thereby reducing the utilization value of blood meal. Summary of the invention

[0008] In order to solve the technical problem of low digestibility of blood meal in the above-mentioned prior art, improve the utilization value of blood meal and improve the digestion and absorption rate, the present invention proposes a method for improving the digestibility of blood meal.

[0009] The technical solution of the present invention is achieved in this way: A method for improving the digestibility of blood meal, comprising the following process steps: (1) Blood collection: When collecting blood, add 0.5-10 kg of anticoagulant to each ton of fresh blood to prevent blood from agglomerating during collection; use a sieve to filter out hair, feces and other impurities to ensure that the blood is pure and has good fluidity; (2) Steaming: Put the blood into a steaming tank with a stirrer and steam it at a certain temperature for a certain period of time until the blood is completely solidified. Then stop steaming and cool it down. (3) Filter pressing: The boiled blood is squeezed and filtered using a squeezing device to obtain a filter cake; (4) Crushing: The filter cake after extrusion is crushed with a pulverizer to obtain semi-dry and wet powder; (5) Drying: The crushed semi-dry wet powder enters a flash drying tower (or other drying equipment) for drying to obtain the blood meal.

[0010] Preferably, the anticoagulant includes all anticoagulant substances such as sodium citrate, EDTA, sodium tripolyphosphate (including but not limited to), or a composite anticoagulant formed by mixing several anticoagulants.

[0011] Preferably, when collecting blood, 0-5 kg ​​of preservatives are added to the fresh blood according to seasonal temperature changes to preserve the blood. The preservatives include preservatives widely used in food such as sodium diacetate, sodium benzoate (including but not limited to), or a preservative compounded with several preservatives.

[0012] Preferably, the collected liquid blood is stored and transported using refrigeration tanks and fresh-keeping transport vehicles according to seasonal temperature changes, or is directly boiled and filtered on site.

[0013] Preferably, the cooking process has a cooking temperature of 70-95°C. The blood is placed in a cooking tank with a stirrer. When the blood temperature reaches 70-95°C, it is further cooked for 0.5-3h. At this time, it is checked whether the blood is completely solidified. If the blood is completely solidified, the process can be stopped without human intervention (adding cold water to the solidified blood) or by naturally cooling the blood to below 70 degrees Celsius.

[0014] Preferably, the boiled blood is squeezed and filtered using squeezing equipment (such as a plate and frame filter press) to filter out 50-60% of the water, so as to reduce energy consumption during drying.

[0015] Preferably, the filter cake after extrusion is crushed by a pulverizer, the fineness of the crushing screen is 1-5 mm, and the crushed semi-dry wet powder is put into a flash drying tower for drying.

[0016] Preferably, the inlet air temperature of the flash drying tower is 180-260 degrees Celsius, the tail air temperature is 60-90 degrees Celsius, and the material residence time is 15-300 seconds for drying. The dried material can be crushed and packaged according to the fineness requirements or can be directly packaged.

[0017] Preferably, the final moisture content of the final product is between 8-12%.

[0018] The blood meal produced by the process of the present invention has the following advantages compared with the blood meal produced by the prior art: 1. Anticoagulants are added when blood is collected to keep the blood in a liquid state at all times and inhibit the formation of fibrinogen from fibrinogen. Because fibrinogen does not form fibrin, the blood meal produced by this process enters the gastrointestinal tract, and the protein is easily digested into amino acids and small peptides, which are absorbed through the intestines to synthesize the nutrients needed by the body.

[0019] 2. Preservatives are added when blood is collected. Through the control of preservatives, bacterial reproduction is inhibited to ensure that the blood is fresh and not deteriorated, and the content of volatile basic nitrogen is reduced. At the same time, the content of histamine and cadaverine in the product is significantly reduced, reducing the damage of harmful substances to the gastrointestinal tract, reducing animal stress, improving palatability, and improving the digestibility of blood products.

[0020] 3. Control of drying temperature. There are two points here: one is that the particle size of semi-dry wet materials should be fine, and the other is that the drying temperature should not be too high. The purpose of fine particle size of wet materials is to take away the materials faster at the same temperature, to avoid long-term high temperature heating of the materials, which will cause thermal denaturation of the protein and Maillard reaction, reduce the digestion and absorption rate of the product, and affect the quality of the product. The fineness used here is through a 1-5 mm sieve. The drying temperature is selected as 180-260 degrees Celsius for inlet air and 60-90 degrees Celsius for tail air. The material stays in the drying tower for 15-300 seconds. This parameter is set to achieve a final moisture content of 8-12% for the product. Too high moisture is not conducive to product storage, and too low moisture will cause great thermal damage to the protein and affect digestion and absorption.

[0021] The beneficial effects of the present invention are summarized as follows: 1. Anticoagulants are added during the blood collection process to make the raw blood liquid. Screening can remove hair, feces and other impurities to ensure the purity of the blood; 2. Anticoagulants inhibit blood coagulation. This inhibitory effect lasts throughout the process of raw material collection, transportation and cooking, making the protein sources in the blood, such as red blood cells, white blood cells, albumin, globulin and fibrinogen, stable. During cooking, these protein sources are deformed by heat and coagulated due to the heat-sensitive effect. This coagulation is a morphological change caused by the thermal deformation of these protein sources themselves. Under the action of anticoagulants, fibrinogen cannot aggregate into fibrin to wrap these protein sources, so that nutrients such as red blood cells, white blood cells, albumin, globulin and fibrinogen are directly exposed in the coagulation; 3. Liquid blood can be stored and transported in refrigerated tanks and refrigerated trucks, ensuring the freshness of the blood and inhibiting bacterial growth; 4. When steaming, cook at a temperature of about 70-95 degrees Celsius for 0.5-3 hours, which can effectively inactivate pathogenic microorganisms in the blood and make the blood powder safer to use. There are strict requirements for the steaming time. Stop steaming immediately after the blood is fully solidified to avoid excessive heating of the protein due to high temperature for too long, which will affect digestion and absorption. Overheating will also deepen the color of the blood; 5. The cooked solids are squeezed to squeeze out 50-60% of the water, crushed with a grinder and then put into a flash drying tower for drying, which can effectively reduce energy consumption; 6. In the flash drying tower, the inlet air temperature is 180-260 degrees Celsius, the tail air temperature is 60-90 degrees Celsius, and the material stays in the tower for 15-300 seconds. This condition control is to avoid the temperature being too high for too long, causing the protein to denature and not be digested and absorbed, and at the same time use high temperature for sterilization and disinfection again. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a photo of the blood meal product obtained in Example 1 of the present invention; Figure 2 This is a photo of a pepsin digestibility test report of the blood meal product obtained in Example 1 of the present invention; Figure 3 This is a photograph of the solid form of blood completely solidified after boiling in Example 1 of the present invention; Figure 4 This is a photograph of the morphology of a completely solidified solid after blood is boiled in the prior art. DETAILED DESCRIPTION

[0023] In order to deepen the understanding of the present invention, the method for improving the digestibility of blood meal of the present invention will be further described in detail below with reference to examples and drawings. This embodiment is only used to explain the present invention and does not constitute a limitation on the protection scope of the present invention.

[0024] Embodiment 1: A method for improving the digestibility of blood meal, the required raw materials are: pig blood, sodium citrate, EDTA, sodium tripolyphosphate, sodium benzoate, sodium diacetate, and the method comprises the following process steps: 1. When collecting blood at the slaughterhouse, add 4 kg of sodium citrate or 3.5 kg of EDTA or 3.5 kg of sodium tripolyphosphate, and 1.5 kg of compound preservative (sodium benzoate 2:1 sodium diacetate). The anticoagulant and preservative are evenly dissolved in water to make a 10% solution and poured into the blood collection trough. Let the blood flow into the trough containing the anticoagulant and preservative and stir it to allow the anticoagulant and preservative solution to fully mix with the blood to achieve the effect of anticoagulation.

[0025] 2. The second step is optional. If the blood is not transported in time, the collected blood must be put into a refrigeration tank for refrigeration and preservation. The refrigeration and preservation temperature is 8-10 degrees Celsius. If the blood is transported in time, it will be transported back to production in time by tank truck. 3. Put the collected blood in liquid state into a cooking tank with a stirrer and turn on the stirrer to stir continuously. Steam is introduced into the cooking tank to continuously increase the blood temperature. When the blood temperature rises to 85 degrees Celsius, stop injecting steam and maintain the temperature of 85 degrees Celsius for 1 hour (if the temperature drops to 83 degrees Celsius at this time, turn on the steam to raise the temperature to ensure that the temperature of 85 degrees Celsius is relatively constant). After the blood is completely matured and solidified, stop heating and keeping warm. At this time, use a pipe to inject cold water into the cooking tank to quickly cool the solidified blood to 60 degrees Celsius. Use a pipe and pump to pump the solids in the cooking tank to the plate and frame filter press for filtration and water squeezing. The pressure of the plate and frame filter press is 6 pressures for 30 minutes. Pour the dehydrated solids into the auger or. Use a universal crusher to crush it and pass it through a 3 mm screen. After screening, the material is transported to the drying tower by an auger or a conveyor belt. Set the inlet air temperature to 230 degrees Celsius and the tail air temperature to 80 degrees Celsius for drying to obtain the finished product.

[0026] In order to prove the beneficial effects of the method of the present invention compared with the prior art, the performance of the blood meal obtained in this example was experimentally tested, and the testing method was in accordance with the standard of GB / T 17811-2008.

[0027] The experimental results are shown in Table 1 below: Table 1. Performance comparison of the blood powder product obtained in Example 1 and the blood powder product in the prior art According to the above experimental results, it can be seen that: From the above experimental results, it can be seen that the liquid blood with anticoagulant added in the present application enters the cooking tank, and the completely solidified solids after cooking are in the form of tofu dregs. Figure 3 As shown. However, in the prior art, blood is mostly in block form after being boiled, such as Figure 4 Compared with block solids, tofu dregs have the following beneficial effects: The blood with added anticoagulants becomes like tofu dregs after cooking. This is because during the cooking process the anticoagulants continue to inhibit fibrinogen from forming fibrin. As the temperature continues to rise, the proteins in the blood, such as red blood cells, white blood cells, albumin, globulin and fibrinogen, undergo thermal deformation and solidify. This solidified material becomes like tofu dregs. When blood without anticoagulants is collected, the fibrinogen has already formed fibrin, which wraps the red blood cells, white blood cells, albumin, globulin and other proteins in the blood into lumps. This state is irreversible, so it also becomes lumpy after cooking.

[0028] The essential difference between blood in a tofu-like state after steaming and blood in a block state is that the nutrients in the tofu-like solids are directly exposed in the solids (it can also be said that this type of solid is made up of nutrients accumulated in the blood). After animals ingest them, these nutrients are directly digested and absorbed by the animals; while the nutrients in the block-like solids are wrapped in fibrin. After animals ingest them, these nutrients cannot be released and used by the animals, and are finally directly excreted from the body.

[0029] The main inventive point of the present invention is that the nutrients in the blood are not wrapped by fibrin, but are directly exposed to the blood meal, so that they can be effectively utilized by animals, which greatly improves the digestion and absorption of the blood meal and significantly improves the utilization rate of the blood meal (fibrin is difficult to digest, and the nutrients wrapped by it cannot be released and digested and utilized by animals).

[0030] Anticoagulants are added during blood collection to inhibit the conversion of fibrinogen into fibrin, so that the pepsin digestibility of the product obtained by boiling the blood in a liquid state is significantly improved. Compared with the blood powder in the prior art, the pepsin digestibility of the blood powder product obtained by the method of the present invention is significantly improved.

[0031] Embodiment 2: A method for improving the digestibility of blood meal, comprising the following process steps: Required raw materials: pig blood, compound anticoagulant (sodium citrate, EDTA, sodium tripolyphosphate, sodium benzoate, sodium diacetate are compounded in a certain proportion) 1. When collecting blood at the slaughterhouse, add 4 kg of compound anticoagulant. Dissolve the compound anticoagulant evenly in water to make a 10% solution and pour it into the blood collection tank. Let the blood flow into the tank containing anticoagulant and preservative and stir it to fully mix the anticoagulant and preservative solution with the blood to achieve the anticoagulant effect. 2. The second step is optional. If the blood is not transported in time, the collected blood must be put into a refrigeration tank for refrigeration and preservation. The refrigeration and preservation temperature is 8-10 degrees Celsius. If the blood is transported in time, it will be transported back to production in time by tank truck. 3. Put the collected blood in liquid state into a cooking tank with a stirrer and turn on the stirrer to stir continuously. Steam is introduced into the cooking tank to continuously increase the blood temperature. When the blood temperature rises to 85 degrees Celsius, stop injecting steam and maintain the temperature of 85 degrees Celsius for 1 hour (if the temperature drops to 83 degrees Celsius at this time, turn on the steam to raise the temperature to ensure that the temperature of 85 degrees Celsius is relatively constant). After the blood is completely matured and solidified, stop heating and keeping warm. At this time, use a pipe to inject cold water into the cooking tank to quickly cool the solidified blood to 60 degrees Celsius. Use a pipe and pump to pump the solids in the cooking tank to the plate and frame filter press for filtration and water squeezing. The pressure of the plate and frame filter press is 6 pressures for 30 minutes. Pour the dehydrated solids into the auger or. Use a universal crusher to crush it and pass it through a 3 mm screen. After screening, the material is transported to the drying tower by an auger or a conveyor belt. Set the inlet air temperature to 230 degrees Celsius and the tail air temperature to 80 degrees Celsius for drying to obtain the finished product.

[0032] In order to prove the beneficial effects of the method of the present invention compared with the prior art, the performance of the blood meal obtained in this example was experimentally tested, and the testing method was in accordance with the standard of GB / T 17811-2008.

[0033] The experimental results are shown in Table 2 below: Table 2. Performance comparison of the blood powder product obtained in Example 2 and the blood powder product in the prior art According to the above experimental results, it can be seen that the addition of the composite anticoagulant prevents the blood from agglomerating when entering the cooking tank, and the completely solidified solids after cooking are in a tofu dregs-like form rather than a block form, which is the same as the effect of using a single anticoagulant, and effectively improves the pepsin digestibility of the produced blood powder. Compared with the blood powder in the prior art, the pepsin digestibility of the blood powder product obtained by the method of the present invention is significantly improved.

[0034] The process described in the present application fundamentally solves the problem of poor digestibility of blood meal. By adding an anticoagulant to prevent fibrinogen from forming fibrin, fresh blood cannot clump, and fresh blood enters the cooking tank in a liquid state.

[0035] The blood meal described in the present application is used in the field of feed.

[0036] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for improving the digestibility of blood meal, characterized in that: The process steps include: (1) Blood collection: When collecting blood, add anticoagulants to fresh blood to prevent blood from agglomerating; use a sieve to filter out hair, feces and other impurities to ensure that the blood is pure and has good fluidity; (2) Steaming: Put the blood into a steaming tank with a stirrer and steam it until the blood is completely solidified. Then stop steaming and cool it down. (3) Filter pressing: The boiled blood is squeezed and filtered using a squeezing device to obtain a filter cake; (4) Crushing: The filter cake after extrusion is crushed with a pulverizer to obtain semi-dry and wet powder; (5) Drying: The crushed semi-dry wet powder is dried to obtain the blood meal.

2. The method for improving the digestibility of blood meal according to claim 1, characterized in that: When blood is collected, 0.5-10 kg of anticoagulant is added to each ton of fresh blood.

3. The method for improving the digestibility of blood meal according to claim 1, characterized in that: When collecting blood, 0-5 kg ​​of preservatives are added to each ton of fresh blood according to seasonal temperature changes to preserve the blood.

4. The method for improving the digestibility of blood meal according to claim 1, characterized in that: The collected liquid blood is stored and transported using refrigeration tanks and fresh-keeping transport vehicles according to seasonal temperature changes, or is directly boiled and filtered on site.

5. The method for improving the digestibility of blood meal according to claim 1, characterized in that: In the cooking process, the cooking temperature is 70-95° C. The blood is placed in a cooking tank with a stirrer. When the blood temperature reaches 70-95° C., it is further cooked for 0.5-3 hours. If the blood is completely solidified, the cooking can be stopped and the temperature can be lowered to below 70° C.

6. The method for improving the digestibility of blood meal according to claim 1, characterized in that: The boiled blood is squeezed and filtered with an extrusion device to filter out 50-60% of the water in order to reduce energy consumption during drying; the filter cake after extrusion is crushed with a pulverizer, the fineness of the crushing screen is 1-5 mm, and the crushed semi-dry wet powder is put into a flash drying tower or other drying equipment for drying.

7. The method for improving the digestibility of blood meal according to claim 1, characterized in that: The inlet air temperature of the flash drying tower is 180-260 degrees Celsius, the tail air temperature is 60-90 degrees Celsius, and the material residence time is 15-300 seconds for drying. The dried material can be crushed and packaged or directly packaged according to the fineness requirements.

8. The method for improving the digestibility of blood meal according to claim 1, characterized in that: The final moisture content of the final product is between 8-12%.

9. The blood meal prepared by the method according to any one of claims 1 to 8, characterized in that: The pepsin digestibility of the blood meal is more than 99%.

10. The use of the blood meal according to claim 9, characterized in that: The blood meal is used in the field of feed.

Images