A processing technology for spray-dried blood meal

Abstract

The present application relates to the technical field of feed additives, and specifically discloses a process for spray-dried blood meal. A process for spray-dried blood meal comprises the following steps: (1) pretreatment: filtering fresh blood to remove residues for standby use; (2) adjusting pH: using sodium citrate buffer solution to adjust the pH value to 6.8-7.2; (3) spray drying: using a high-precision centrifugal pump to transport the adjusted blood into a spray tower for spray drying; (4) permeate treatment: dispersing the powder formed by spray drying in the permeate, treating at 25-30°C for 3-3.5h, centrifuging, drying at 30-35°C, and reducing the moisture content to 40-60%, and then performing variable temperature pressure difference puffing treatment; (5) coating: coating the powder formed by spray drying through a fluidized bed, and packaging and storage; In addition, the preparation method of the present application has the advantages of increasing the nutrient content and digestibility of the product blood meal.

Description

Technical Field

[0001] The present application relates to the technical field of feed additives, and more specifically, to a processing technology for spray-dried blood meal. Background Art

[0002] Blood meal is a substance containing a variety of proteins and amino acids. It can be used as a feed additive to provide nutrients for poultry and livestock. At the same time, it can recycle animal blood and reduce the waste rate. At present, animal blood is mainly recycled through boiling, drying and other processes to make blood meal, which is used as a feed additive.

[0003] However, in the traditional processing method, the animal blood needs to be heated, so that the active substances in the blood that are not resistant to high temperatures, such as tryptophan and lysine, are destroyed under high temperatures, affecting the nutritional value of the blood meal. At the same time, the blood contains easily oxidizable substances such as divalent iron ions, which are oxidized during the processing process, which will also reduce the quality of the blood meal product and the digestibility of the blood meal is poor. Summary of the invention

[0004] In order to improve the nutrient content and digestibility of blood meal products, the present application provides a processing technology for spray-drying blood meal.

[0005] A process for spray-drying blood powder comprises the following steps:

[0006] (1) Pretreatment: Filter the fresh blood to remove the residue for later use;

[0007] (2) Adjust pH: Use sodium citrate buffer solution to adjust the pH value to 6.8-7.2;

[0008] (3) Spray drying: Use a high-precision centrifugal pump to transport the conditioned blood into a spray tower for spray drying;

[0009] (4) Permeate treatment: The powder formed by spray drying is dispersed in the permeate, treated at 25-30°C for 3-3.5 hours, centrifuged, dried at 30-35°C, and after the moisture content is reduced to 40-60%, variable temperature and pressure differential expansion treatment is performed;

[0010] (5) Coating: The powder formed by spray drying is coated in a fluidized bed and packaged for storage.

[0011] By adopting the above technical scheme, fresh blood is spray-dried to form blood powder particles. The blood powder is controlled to be in a low temperature state during the spray-drying process, which can effectively reduce the destruction and oxidation of nutrients in the blood, such as active substances such as proteins and amino acids. The blood powder particles are immersed in a permeate and then subjected to a variable temperature and pressure difference expansion treatment, so that the tissue structure of the blood powder particles is porous, which is easy for external liquids, such as digestive juices of poultry and livestock to enter, and effectively promotes the digestion and absorption of the blood powder. The expanded blood powder is subjected to a coating treatment, and the coating can reduce the contact between the blood powder and moisture and oxygen in the external environment, which is beneficial to the long-term storage of the blood powder and the retention of nutrients.

[0012] Preferably, the flow rate of the spray drying is 190-210 L / min, the pressure is 2.8-3.2 MPa, and the temperature is 45-50°C.

[0013] By adopting the above technical solution, the flow rate, pressure and temperature conditions of spray drying are controlled, so that the blood powder obtained by spray drying has a smaller and more uniform particle size, and is dried more fully, which is conducive to the formation of blood powder.

[0014] Preferably, the permeate comprises 18-22 wt % of maltodextrin and 9-11 wt % of whey protein isolate, with the remainder being water.

[0015] By adopting the above technical solution, maltodextrin and whey protein isolate can enter the blood meal particles with the permeate, support the tissue structure in the particles during the puffing process, reduce the collapse of the tissue structure during the puffing process, and enable the blood meal particles to maintain a good porous structure and pore channels, which is beneficial to the digestion and decomposition of the blood meal.

[0016] Preferably, in the variable temperature and pressure difference puffing, the puffing temperature is 50-55°C, the stagnation time is 5-8 minutes, and the evacuation temperature is 40-45°C.

[0017] By adopting the above technical scheme, the temperature, stop time and evacuation temperature of variable temperature and pressure difference puffing are controlled, so that the puffing degree, moisture content and nutrient retention rate of blood meal can be effectively controlled. Too high temperature can easily cause oxidation loss of nutrients, while too low temperature will reduce the puffing degree and affect its digestibility.

[0018] Preferably, the coating solution used in the coating comprises the following raw materials in weight percentage: 4-8% basic film-forming substance, 1-2% glycerol, and 0.6-0.8% composite antioxidant, wherein the basic film-forming substance is a composite of chitosan and soy protein isolate, and the composite antioxidant is a composite of astaxanthin and vitamin C.

[0019] By adopting the above technical scheme, the chitosan film has high water permeability, low gas barrier properties, but good mechanical properties. The compounding of chitosan and soy protein isolate can improve the low moisture resistance of the coating, forming an edible film with good mechanical properties and good water- and oxygen-blocking properties. At the same time, the composite antioxidant can effectively improve the antioxidant properties of the coating liquid after film formation, reducing the oxidative loss of ferrous ions, amino acids, etc. in blood meal.

[0020] Preferably, the method for preparing the coating solution comprises the following steps: dispersing chitosan and soy protein isolate in water, adding glycerol and a composite antioxidant, and stirring with a magnetic force until the mixture is uniformly mixed to obtain the coating solution.

[0021] By adopting the above technical solution, the preparation method of the coating solution is simple, and the prepared coating solution has good fluidity and viscosity, which is beneficial to the uniformity and integrity of the coating.

[0022] Preferably, in the basic film-forming material, the mass ratio of chitosan to soy protein isolate is (4.23-4.71):(1.2-1.68).

[0023] By adopting the above technical solution and controlling the mass ratio of chitosan to soy protein isolate, the coating formed by the basic film-forming material has good mechanical strength and good water-blocking and oxygen-blocking properties, which can provide better protection for the blood meal particles inside the coating and prolong its storage time.

[0024] Preferably, in the composite antioxidant, the mass ratio of astaxanthin to vitamin C is (0.8-1.2):(1.1-1.5).

[0025] By adopting the above technical solution, astaxanthin and vitamin C are compounded according to the mass ratio, which has a synergistic effect and can effectively provide antioxidant properties of the coating.

[0026] In summary, this application has the following beneficial effects:

[0027] 1. In the present application, fresh blood is spray-dried to form blood powder particles. During the spray-drying process, the blood powder particles are kept in a low temperature state, which can effectively reduce the destruction and oxidation of nutrients in the blood, such as active substances such as proteins and amino acids. The blood powder particles are immersed in a permeate and then subjected to a variable temperature and pressure difference expansion treatment, so that the tissue structure of the blood powder particles is porous, which is easy for external liquids, such as digestive fluids of poultry and livestock to enter, and effectively promotes the digestion and absorption of the blood powder. The expanded blood powder is coated, and the coating can reduce the contact between the blood powder and moisture and oxygen in the external environment, which is beneficial to the long-term storage of the blood powder and the retention of nutrients.

[0028] 2. In the present application, the permeate contains maltodextrin and whey protein isolate. Maltodextrin and whey protein isolate can enter the blood powder particles along with the permeate, support the tissue structure in the particles during the puffing process, reduce the collapse of the tissue structure during the puffing process, and enable the blood powder particles to maintain a good porous structure and pore channels, which is beneficial to the digestion and decomposition of the blood powder.

[0029] 3. In the present application, the chitosan film has high water permeability, low gas barrier properties, but good mechanical properties. The chitosan is compounded with soy protein isolate to improve the low moisture resistance of the coating and form an edible film with good mechanical properties and good water and oxygen barrier properties. At the same time, the composite antioxidant can effectively improve the antioxidant properties of the coating liquid after film formation, reducing the oxidative loss of ferrous ions, amino acids, etc. in blood powder. DETAILED DESCRIPTION

[0030] The present application is further described in detail below with reference to the embodiments.

[0031] Preparation Example

[0032] Preparation Example 1

[0033] The coating solution includes the following raw materials in weight percentage: 4% basic film-forming substance, 1% glycerol, and 0.6% composite antioxidant. The basic film-forming substance is composed of chitosan and soy protein isolate in a mass ratio of 4.23:1.2, and the composite antioxidant is composed of astaxanthin and vitamin C in a mass ratio of 0.8:1.1.

[0034] The method for preparing the coating liquid comprises the following steps: dispersing chitosan and soy protein isolate in water, adding glycerol and composite antioxidant, and stirring by magnetic force until the mixture is uniformly mixed to obtain the coating liquid.

[0035] Preparation Example 2

[0036] The coating solution includes the following raw materials in weight percentage: 8% basic film-forming substance, 2% glycerol, and 0.8% composite antioxidant. The basic film-forming substance is composed of chitosan and soy protein isolate in a mass ratio of 4.71:1.68, and the composite antioxidant is composed of astaxanthin and vitamin C in a mass ratio of 1.2:1.5.

[0037] The method for preparing the coating liquid comprises the following steps: dispersing chitosan and soy protein isolate in water, adding glycerol and composite antioxidant, and stirring by magnetic force until the mixture is uniformly mixed to obtain the coating liquid.

[0038] Preparation Example 3

[0039] The coating solution includes the following raw materials in weight percentage: 6% basic film-forming substance, 1.5% glycerol, and 0.7% composite antioxidant. The basic film-forming substance is composed of chitosan and soy protein isolate in a mass ratio of 4.65:1.54, and the composite antioxidant is composed of astaxanthin and vitamin C in a mass ratio of 1:1.3.

[0040] The method for preparing the coating liquid comprises the following steps: dispersing chitosan and soy protein isolate in water, adding glycerol and composite antioxidant, and stirring by magnetic force until the mixture is uniformly mixed to obtain the coating liquid.

[0041] Preparation Example 4

[0042] The difference between Preparation Example 4 and Preparation Example 1 is that in Preparation Example 4, the mass ratio of chitosan to soy protein isolate is 4.23:0.8.

[0043] Preparation Example 5

[0044] The difference between Preparation Example 5 and Preparation Example 1 is that in Preparation Example 5, the mass ratio of chitosan to soy protein isolate is 4.23:2.98.

[0045] Preparation Example 6

[0046] The difference between Preparation Example 6 and Preparation Example 1 is that in Preparation Example 6, the mass ratio of astaxanthin to vitamin C is 0.8:0.5.

[0047] Preparation Example 7

[0048] The difference between Preparation Example 7 and Preparation Example 1 is that in Preparation Example 7, the mass ratio of astaxanthin to vitamin C is 0.8:2.6.

[0049] Example

[0050] Example 1

[0051] A process for spray-drying blood powder comprises the following steps:

[0052] (1) Pretreatment: Filter the fresh blood to remove the residue for later use;

[0053] (2) Adjust pH: Use sodium citrate buffer solution to adjust the pH to 6.8;

[0054] (3) Spray drying: Use a high-precision centrifugal pump to transport the conditioned blood into the spray tower for spray drying. The spray drying flow rate is 190 L / min, the pressure is 2.8 MPa, and the temperature is 45°C.

[0055] (4) Permeate treatment: The powder formed by spray drying is dispersed in a permeate comprising 18 wt% maltodextrin and 9 wt% whey protein isolate, with the remainder being water. The mixture is treated at 25°C for 3.5 h, centrifuged, and dried at 35°C. After the moisture content is reduced to 40%, variable temperature and pressure differential puffing treatment is performed. During the variable temperature and pressure differential puffing, the puffing temperature is 50°C, the stagnation time is 5 min, and the evacuation temperature is 40°C.

[0056] (5) Coating: The powder formed by spray drying is coated in a fluidized bed and packaged for storage. The coating liquid is the coating liquid prepared in Preparation Example 1.

[0057] Example 2

[0058] A process for spray-drying blood powder comprises the following steps:

[0059] (1) Pretreatment: Filter the fresh blood to remove the residue for later use;

[0060] (2) Adjust pH: Use sodium citrate buffer solution to adjust the pH to 7.2;

[0061] (3) Spray drying: Use a high-precision centrifugal pump to transport the conditioned blood into the spray tower for spray drying. The spray drying flow rate is 210 L / min, the pressure is 3.2 MPa, and the temperature is 50°C.

[0062] (4) Permeate treatment: The powder formed by spray drying is dispersed in a permeate comprising 22 wt% maltodextrin and 11 wt% whey protein isolate, with the remainder being water. The mixture is treated at 30°C for 3 h, centrifuged, and dried at 35°C. After the moisture content is reduced to 60%, variable temperature and pressure differential puffing is performed. During the variable temperature and pressure differential puffing, the puffing temperature is 55°C, the stagnation time is 8 min, and the evacuation temperature is 45°C.

[0063] (5) Coating: The powder formed by spray drying is coated in a fluidized bed and packaged for storage. The coating liquid is the coating liquid prepared in Preparation Example 2.

[0064] Example 3

[0065] A process for spray-drying blood powder comprises the following steps:

[0066] (1) Pretreatment: Filter the fresh blood to remove the residue for later use;

[0067] (2) Adjust pH: Use sodium citrate buffer solution to adjust the pH to 7;

[0068] (3) Spray drying: Use a high-precision centrifugal pump to transport the conditioned blood into a spray tower for spray drying. The spray drying flow rate is 200 L / min, the pressure is 3 MPa, and the temperature is 48°C.

[0069] (4) Permeate treatment: The powder formed by spray drying is dispersed in a permeate comprising 20 wt% maltodextrin and 10 wt% whey protein isolate, with the remainder being water. The mixture is treated at 27°C for 3 h, centrifuged, and dried at 30°C. After the moisture content is reduced to 50%, variable temperature and pressure differential puffing is performed. During the variable temperature and pressure differential puffing, the puffing temperature is 50°C, the stagnation time is 6 min, and the evacuation temperature is 40°C.

[0070] (5) Coating: The powder formed by spray drying is coated in a fluidized bed and packaged for storage. The coating liquid is the coating liquid prepared in Preparation Example 3.

[0071] Example 4

[0072] The difference between Example 4 and Example 1 is that the permeate includes 12 wt % of maltodextrin and 6 wt % of whey protein isolate, and the balance is water.

[0073] Example 5

[0074] The difference between Example 5 and Example 1 is that the permeate includes 28 wt % of maltodextrin and 15 wt % of whey protein isolate, and the balance is water.

[0075] Example 6

[0076] The difference between Example 6 and Example 1 is that the flow rate of spray drying is 160 L / min, the pressure is 2.1 MPa, and the temperature is 45°C.

[0077] Example 7

[0078] The difference between Example 7 and Example 1 is that the flow rate of spray drying is 250 L / min, the pressure is 4 MPa, and the temperature is 50°C.

[0079] Example 8

[0080] The difference between Example 8 and Example 1 is that in the variable temperature and pressure difference expansion, the expansion temperature is 40°C.

[0081] Example 9

[0082] The difference between Example 9 and Example 1 is that in the variable temperature and pressure difference expansion, the expansion temperature is 65°C.

[0083] Example 10

[0084] The difference between Example 10 and Example 1 is that in the variable temperature pressure difference expansion, the evacuation temperature is 30°C.

[0085] Embodiment 11

[0086] The difference between Example 11 and Example 1 is that, in the variable temperature pressure difference expansion, the evacuation temperature is 55°C.

[0087] Example 12

[0088] The difference between Example 12 and Example 1 is that the coating liquid is the coating liquid prepared in Preparation Example 4.

[0089] Embodiment 13

[0090] The difference between Example 13 and Example 1 is that the coating liquid is the coating liquid prepared in Preparation Example 5.

[0091] Embodiment 14

[0092] The difference between Example 14 and Example 1 is that the coating liquid is the coating liquid prepared in Preparation Example 6.

[0093] Embodiment 15

[0094] The difference between Example 15 and Example 1 is that the coating liquid is the coating liquid prepared in Preparation Example 7.

[0095] Comparative Example

[0096] Comparative Example 1

[0097] The difference between Comparative Example 1 and Example 1 is that in Comparative Example 1, the blood powder is not treated with permeate before being subjected to variable temperature and pressure difference puffing treatment.

[0098] Comparative Example 2

[0099] The difference between Comparative Example 2 and Example 1 is that in Comparative Example 2, the blood powder is not subjected to variable temperature and pressure difference puffing treatment.

[0100] Comparative Example 3

[0101] The difference between Comparative Example 3 and Example 1 is that in Comparative Example 3, the blood powder is not coated.

[0102] Detection Methods

[0103] The blood powders prepared in Examples 1-15 and Comparative Examples 1-3 were tested, and the proportions of total amino acids and lysine were tested according to the Kjeldahl nitrogen determination method (GB / T14771-93), and the results are recorded in Table 1;

[0104] The in vitro digestibility was tested according to the "Determination of pepsin digestibility of animal protein feed by filtration method (GB / T17811-2008)" and recorded in Table 1;

[0105] After the blood meal was dried and stored for 3 months, its antioxidant properties were detected by the change in the content of ferrous ions in the blood meal, and the loss rate of ferrous ions was calculated and recorded in Table 1.

[0106] Table 1 Blood meal product performance test

[0107] According to Table 1, Examples 1-3 and Comparative Examples 1-3, it can be seen that the blood meal prepared in Examples 1-3 has better nutrient content and digestibility than Comparative Examples 1-3, lower ferrous ion loss rate than Comparative Examples 1-3, and better antioxidant performance. In Examples 1-3, fresh blood is first spray-dried to form blood meal particles, and then the blood meal particles are immersed in a permeate, and the blood meal particles are expanded by variable temperature and pressure difference puffing treatment. The porous tissue structure increases the contact area with the digestive juice, thereby improving the digestibility and facilitating the digestion and absorption of the blood meal. At the same time, the coating treatment reduces the contact between the blood meal and the external moisture and oxygen, thereby improving its antioxidant performance and storage time.

[0108] Comparative Example 1 was not treated with permeate, and Comparative Example 2 was not treated with variable temperature and pressure differential puffing. The digestibility of Comparative Example 1-2 was reduced, indicating that the permeate can improve the effect of the variable temperature and pressure differential puffing treatment, and the variable temperature and pressure differential puffing treatment can effectively increase the porosity of the blood meal particles, facilitate the immersion of the digestive fluid, increase the contact area between the blood meal particles and the digestive fluid, and help improve the digestibility of the blood meal; Comparative Example 3 was not coated, and the ferrous ion content was lost a lot after storage, and the degree of oxidation was high during the storage process, indicating that the coating treatment can effectively improve the antioxidant properties of the blood meal particles.

[0109] Compared with Example 1-3, the blood meal prepared in Example 4-5 has decreased nutrient content and digestibility. Example 4-5 changes the composition of the permeate, and maltodextrin and whey protein isolate can penetrate into the blood meal particles with the permeate, and support the internal tissue structure of the blood meal particles during the variable temperature and pressure difference puffing process. During the puffing process, water evaporates, and the collapse of the internal structure is reduced. The blood meal particles can maintain a good porous structure and pores, which is conducive to the penetration, contact and digestion of the digestive fluid. The content of maltodextrin and whey protein isolate is reduced, and its permeation effect is weakened, and the effect of the permeate becomes worse. The content of maltodextrin and whey protein isolate is increased, and its viscosity is too large, which will also weaken the effect of the permeate, thereby affecting the tissue structure of the blood meal particles after puffing, and easily causing the loss of nutrients.

[0110] Compared with Example 1-3, the nutrient content and digestibility of the blood powder obtained in Example 6-7 are reduced. Example 6-7 changes the flow rate and pressure of spray drying, controls the flow rate, pressure and temperature conditions of spray drying, so that the blood powder obtained by spray drying has a smaller and more uniform particle size, and is dried more fully, which is conducive to the molding of the blood powder. However, changing the flow rate and pressure results in poor molding of the blood powder particles, uneven tissue structure, uneven drying degree of each part, partial loss of nutrients, and affects the treatment effect of the permeate and the treatment effect of the variable temperature and pressure difference puffing, thereby reducing the digestibility.

[0111] Compared with Examples 1-3, the blood meal prepared in Example 8-11 has decreased nutrient content and digestibility. Example 8-9 changed the puffing temperature, and Example 10-11 changed the vacuum temperature. If the puffing temperature and the vacuum temperature are too low, the puffing degree of the blood meal particles will decrease, and the internal porosity will decrease, affecting its digestibility. If the puffing temperature and the vacuum temperature are too high, the nutrients inside the blood meal particles will be decomposed and oxidized by heat during the processing process, and the nutritional components will be affected, resulting in decreased quality of the blood meal.

[0112] Compared with Example 1-3, the blood meal prepared in Example 12-13 has a higher ferrous ion loss rate than that in Comparative Example 1-3, and its antioxidant performance is reduced. When preparing the coating liquid, Example 12-13 changed the mass ratio of chitosan to soy protein isolate. The chitosan film has high water permeability and low gas barrier properties, but good mechanical properties. Compounding chitosan with soy protein isolate can improve the low moisture barrier properties of the coating and form an edible film with good mechanical properties and good water- and oxygen-blocking properties. The mass ratio of the two is changed, which reduces the mechanical properties or water- and oxygen-blocking properties of the coating, thereby reducing the antioxidant performance of the coating and reducing the protective effect on the blood meal particles.

[0113] Compared with Example 1-3, the blood meal prepared in Example 14-15 has a higher ferrous ion loss rate than that in Comparative Example 1-3, and its antioxidant performance is reduced. When preparing the coating liquid in Example 14-15, the mass ratio of astaxanthin and vitamin C is adjusted, and astaxanthin and vitamin C are compounded according to the mass ratio, which has a synergistic effect and can effectively provide the antioxidant performance of the coating. When the mass ratio of astaxanthin and vitamin C changes, the synergistic effect of the two is weakened, and the antioxidant performance of the coating is reduced.

[0114] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make modifications to the present embodiment without any creative contribution as needed, but such modifications are protected by the patent law as long as they are within the scope of the claims of the present application.

Claims

1. A process for spray-drying blood powder, characterized in that: The following steps are involved: (1) Pretreatment: Filter the fresh blood to remove the residue for later use; (2) Adjust pH: Use sodium citrate buffer solution to adjust the pH value to 6.8-7.2; (3) Spray drying: Use a high-precision centrifugal pump to transport the regulated blood into a spray tower for spray drying. The spray drying flow rate is 190-210 L / min, the pressure is 2.8-3.2 MPa, and the temperature is 45-50°C; (4) Permeate treatment: the powder formed by spray drying is dispersed in a permeate, wherein the permeate comprises 18-22 wt% of maltodextrin and 9-11 wt% of whey protein isolate, and the remainder is water. After treatment at 25-30°C for 3-3.5 h, the mixture is centrifuged and dried at 30-35°C. After the moisture content is reduced to 40-60%, variable temperature and pressure differential puffing treatment is performed. In the variable temperature and pressure differential puffing, the puffing temperature is 50-55°C, the stagnation time is 5-8 min, and the evacuation temperature is 40-45°C. (5) Coating: The powder formed by spray drying is coated via a fluidized bed, wherein the coating solution used in the coating comprises the following raw materials in weight percentage: 4-8% basic film-forming substance, 1-2% glycerol, and 0.6-0.8% composite antioxidant, wherein the basic film-forming substance is a composite of chitosan and soy protein isolate, wherein the mass ratio of chitosan to soy protein isolate is (4.23-4.71):(1.2-1.68), and the composite antioxidant is a composite of astaxanthin and vitamin C, wherein the mass ratio of astaxanthin to vitamin C is (0.8-1.2):(1.1-1.5), and the mixture is packaged and put into storage.

2. The process for spray-drying blood powder according to claim 1, characterized in that: The method for preparing the coating liquid comprises the following steps: dispersing chitosan and soybean protein isolate in water, adding glycerol and a composite antioxidant, and stirring by magnetic force until the mixture is uniform to obtain the coating liquid.