JPH0737355B2 - Blood drying method - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a blood drying treatment method for processing blood discharged during meat slaughter of livestock animals as fertilizer or feed.

[Prior Art] A large amount of protein is contained in blood discharged when meat of livestock animals such as cows and pigs is slaughtered. As one of the methods for effectively using this blood protein, blood is dried and used as fertilizer or feed.

Although various methods have been proposed in the past for treating blood that goes out during meat slaughter, a method that utilizes heat-denatured coagulation of proteins is generally used. In this method, the protein in the blood is heat-denatured and coagulated by means such as ejecting high-temperature steam into the blood, and then only the coagulated blood is separated by a solid-liquid separation device, and the coagulated blood is dried. Is the way.

[Problems to be Solved by the Invention] However, in the above method, the blood protein is coagulated only by heat denaturation, so that the protein coagulation efficiency is low,
In particular, there is a disadvantage that the efficiency of treatment is low because the soluble protein is not escaped. Further, since the protein coagulated by heat denaturation becomes agglomerates that exhibit viscosity, the blood after heat denaturation becomes a highly viscous sludge-like fluid containing agglomerates,
There is a disadvantage that the handling property in the solid-liquid separation step and the drying step is lowered. Further, when the sludge-like fluid containing the above-mentioned agglomerates is dried, it becomes a fine powder having a low bulk density, and there is a disadvantage that a granular product cannot be obtained.

The present invention has been made to solve the above-mentioned problems, and is a method of coagulating blood proteins with high efficiency, and drying to easily obtain a product made of a granular protein coagulated product with good handleability. It is intended to provide a treatment method.

[Means for Solving the Problems] The method for drying blood according to the present invention is characterized in that after the blood is subjected to pH treatment for neutralizing with an alkali after adding an acid,
The solution was to subject it to a heat denaturation treatment and then to dry it. The blood referred to herein includes whole blood and blood cell fluid obtained by separating whole blood into plasma and blood cell fluid.

[Action] Since the pH treatment is performed before the blood protein is heat-denatured and coagulated, the protein can be coagulated with high efficiency.

Hereinafter, the present invention will be described in detail.

The blood used in the present invention may be one that is discharged during meat slaughter of livestock animals represented by pigs, cows, sheep, etc., and it may be fresh blood or old blood over time. Although good, old blood is preferably fresh blood immediately after disassembling in consideration of handling points such as decrease in fluidity and increase in reagent amount during pH treatment described later.

FIG. 1 shows each step of an example of the method for drying blood according to the present invention. The process will be described below with reference to the process chart.

Hemolysis Treatment In carrying out the method of the present invention, first, blood of a livestock animal or the like discharged during meat slaughter is collected, and then hemolysis treatment such as stirring is performed. This hemolytic treatment is for uniformly liquefying a part of the protein already coagulated in blood, and for enabling the coagulation of globin protein in erythrocytes in the subsequent pH treatment with higher efficiency, The purpose is to destroy the red blood cell membrane and disperse the hemoglobin contained therein into the blood. In carrying out the method of the present invention, it is not always necessary to perform this hemolytic treatment,
After blood collection, the pH treatment described below may be performed directly.

pH treatment-a Acid addition Acid such as hydrochloric acid is appropriately added with stirring so that the pH of blood collected from livestock animals or the blood subjected to the above hemolysis treatment will be 1.7 or more and 4.0 or less. This acid addition step is
It is for cleaving the bond between heme, which is the pigment component of hemoglobin, which occupies most of the proteins in blood, and globin, which is a protein component, to give globin with low solubility in neutral water. The amount to be added is appropriately selected depending on the type and properties of blood to be treated. The number of red blood cells and the number of hemoglobin contained in blood differ depending on the species of the animal, and there are individual differences, and since the numbers also change in fresh blood and old blood, pH is measured while adding acid and stirring, pH is
1.7 or more and 4.0 or less, and particularly preferably 3 or more and 4 or less. This is because when the pH of blood is 3 or more and 4 or less, the binding of heme with globin is most efficiently cleaved.

-B Neutralization treatment In the pair, neutralization is carried out by adding an alkali such as sodium hydroxide with stirring to blood whose pH has been adjusted to 1.7 or more and 4.0 or less by the above acid addition. By this neutralization treatment, globin is deposited in blood as an insoluble coagulation product. This utilizes the irreversible decomposition reaction of hemoglobin into heme and globin, and the solubility of globin in water. That is, after the bond between heme and globin is once cleaved, the bond does not regenerate due to liquidity, and globin dissolves in acidic water with a pH of 6 or less with high solubility, but pH 7
Utilizing the fact that it is insoluble in neutral to weakly alkaline water of about 8 to 8, globin can be precipitated as an insoluble coagulated product by neutralizing the acid-added blood. By stirring the blood during this neutralization treatment, it is possible to deposit a fine globin coagulum that becomes a nucleus of a protein that is thermally coagulated and precipitated in the heat treatment step described later. By precipitating this globin coagulated substance to form a nucleus, the thermally coagulated protein can be prevented from growing into a block-like large lump and granular material as in the conventional case.

Further, the protein precipitated as a coagulation product during this pH treatment is only globin obtained by decomposing hemoglobin contained in erythrocytes, and other protein components such as albumin and globulin in blood are dissolved. Since it remains in the liquid as a component, the blood after pH treatment becomes gravel or mud-like sludge with a large amount of water, but it has low viscosity and is highly fluid, so handleability does not deteriorate. .

The addition amount of acid and alkali required for this pH treatment is
It is appropriately selected depending on the type and condition of blood to be treated. For example, bovine blood is easier to coagulate than pig blood, and the coagulated material is gravel. Further, since old blood requires a larger amount of acid than fresh blood, it is better to perform pH treatment as soon as possible in order to dry blood by the method of the present invention.

Heat Denaturation Treatment Above, the blood in which globin is coagulated by the pH treatment to form fine nuclei is heated while stirring, and the protein component in the blood which is not coagulated by the pH treatment is thermally denatured to be coagulated. The protein components in blood that are not coagulated by the pH treatment include albumin and globulin contained in plasma and a very small amount of globin that is dissolved as a dissolved component without being coagulated by the pH treatment. The heating temperature is such that the liquid temperature is 60 ° C or higher and 75 ° C or lower, and the heating method is an internal heating method in which a heating element is provided in the container even if it is an external heating method from outside the container filled with blood. May be. When the heating temperature is 60 ° C. or lower, the efficiency of this heat denaturation treatment step is low, which is not preferable, and when the heating temperature is 75 ° C. or higher, carbonization of a part of the protein proceeds and the heat coagulation of the protein is It is not preferable because it rapidly progresses, a large amount of large aggregates are generated, and the quality of the product deteriorates.

In blood that is subjected to heat denaturation treatment, since the globin coagulum that serves as the nucleus when coagulation occurs due to heat denaturation of the protein has already been formed by the above pH treatment, the protein that is coagulated by this heat denaturation treatment is: The treatment efficiency does not decrease because it is preferentially deposited on the surface of the nuclei made of globin coagulate rather than on the wall surface of the container. Furthermore, since the globin coagulated product is the core, large block-shaped aggregates are not formed, and the subsequent drying process can be easily performed.

The blood on which the protein coagulated product is formed in this manner is supplied into a dryer which is subjected to the following drying treatment. At this time, a dehydration step of dehydrating the free water may be performed to concentrate, but in order to obtain granular dry blood, it is preferable to perform the drying treatment while containing a slight amount of the free water.

Drying Treatment Next, the blood containing the heat-coagulated protein is heated at a heating temperature near the boiling point of blood (and about 100 ° C.) while being sufficiently stirred, and dried.

This drying treatment step is a step of coagulating a part of the water-soluble proteins that could not be coagulated by the heat denaturation treatment by heating at high temperature, and evaporating water in the blood to give dried blood. By carrying out after the above heat denaturation treatment, the protein in blood can be obtained as a coagulum with high efficiency. In addition, in this treatment step, heat coagulation of water-soluble protein in blood progresses preferentially over evaporation of water, and at the same time, particles of protein coagulation are formed into large lumps due to evaporation of water after heat coagulation of protein. The dried blood obtained is in the form of granules because it does not aggregate into granules.

Further, during this treatment, the blood is in a boiling state, so that vigorous water evaporation occurs, and a large amount of steam generated at this time and the stirring action in the heating container disperse the coagulation protein, so that the globin coagulation product is large. It is possible to prevent agglomerates and obtain granular dry blood.

As described above, the method for drying blood according to the present invention utilizes the physical and chemical properties of each component of protein in blood, and is divided into three steps of pH treatment, heat denaturation treatment and drying treatment. Since it is performed, the treatment effect is remarkably improved as compared with the conventional treatment method, and granular high-quality dried blood can be obtained.

[Example] (Example) 10 liters of fresh whole blood of a pig containing 20% by weight of solid content was obtained from a meat slaughterhouse, and stirred for 10 minutes at 500 rpm in an emulsifying machine to remove already solidified solid matter. A blood sample in which hemoglobin contained in erythrocytes was dispersed by uniform liquefaction and hemolysis was prepared.

The hemolyzed blood sample is then gently stirred for 35
When 100% by weight of hydrochloric acid was added dropwise until the pH of the blood sample reached 3.5, the blood sample became a blackish brown mud. Then, while slowly stirring this dark brown mud-shaped blood, 10N sodium hydroxide was added to the blood sample at a pH of 7.
When it was dropped until it reached 0, 100 ml was required, and the blood sample was a mud-like material in which fine gravel-like coagulated material was dispersed.

20 lS of the blood sample in the form of mud in which this gravel-like coagulated substance is dispersed
It was taken into a US container, and the bottom of the container was stirred while heating with a 1.2 kW electric heater. After heating for 30 minutes, the liquid temperature became 63 ° C., and it became a mud-like substance in which a gravel-like thermally solidified substance was deposited.

40 l of the blood sample that has been subjected to the above steps is easily prepared, and this is put into a torus disk TDS-12-3 of a uniaxial steam-heated conduction heat transfer type stirring dryer (manufactured by Hosokawa Micron Co., Ltd.) and dried. did. The operating conditions at this time are as follows.

Heating method: 130 ° C. (1.7 kg / cm ² g) steam was introduced into the jacket and rotor.

Rotor speed: 40 RPM Blood supply method: A batch drying operation was performed in which the total amount of 40 l was added.

This drying treatment was performed for 90 minutes to obtain black brown powdery dry blood. When the physical properties of this dried blood were examined, it was confirmed that the dried blood was a granular material having a high density.

Density: 0.81g / cm ³ Moisture content: 9.2% Particle size distribution: 1.0mm or more 31% by weight 1.0 to 0.5mm 19% by weight 0.5 to 0.25mm 40% by weight 0.25 to 0.1mm 8% by weight 0.1mm or less 2% by weight ( Comparative Example) When used in Examples, exactly the same whole blood was collected in beakers separately in 200 g portions, one blood sample was subjected to pH treatment in exactly the same manner as in Examples, and the other was not subjected to pH treatment. As it is,
Both were placed on a hot plate, stirred and heated under exactly the same conditions, and the effectiveness of pH treatment was investigated.

A blood sample that has been subjected to pH treatment has a liquid temperature of 65 ° C,
Thermal coagulation started, and free water disappeared at 75 ° C, resulting in gravel. Further, there was no adhesion to the beaker wall, and the obtained gravel-like material had a uniform particle size.

On the other hand, a blood sample that is not treated with pH is less likely to coagulate even when heated, and starts coagulating only when the temperature reaches 75 ° C, and if heating is continued thereafter, a coagulum in the form of dumplings is generated and even on the beaker wall. A large amount of coagulated material adhered.

From the above results, by applying pH treatment to blood, it is possible to reduce the amount of heat required during heat denaturation treatment, prevent adhesion to the container wall, and easily obtain a granular coagulated product. It was confirmed that pH treatment was a very effective treatment process.

[Effects of the Invention] As described above, the method for drying blood according to the present invention is
PH neutralized by alkali after adding acid to blood
Since the treatment is followed by heat denaturation and then drying, it is possible to obtain dry blood with high treatment efficiency, high bulk density and good handling.

In addition, this processing method is based on physical treatment of each component of protein in blood,
Utilizing chemical properties, the coagulation treatment is performed in this order in three steps, pH treatment, heat denaturation treatment, and drying treatment, so protein coagulation efficiency is significantly improved compared to conventional treatment methods. At the same time, granular high-quality dried blood can be obtained.

Further, in particular, by performing the pH treatment, it is possible to reduce the amount of heat required for the heat denaturation treatment, the heat treatment, etc., and it is possible to obtain high-quality dried blood at low cost.

[Brief description of drawings]

FIG. 1 is a process drawing showing each process of one embodiment of the drying treatment method of the present invention. ...... pH treatment, ...... heat denaturation treatment, ...... drying treatment.

Front page continuation (72) Inventor Haruhiko Nagasawa 1-9-3 Kamatahonmachi, Ota-ku, Tokyo Inside Niigata Iron Works Engineering Center Co., Ltd. (56) References JP-B 28-4016 (JP, B1) JP-B Sho 29 -7163 (JP, B1) JP 30-3018 (JP, B1) JP 52-5779 (JP, B2)

Claims (1)

[Claims] 1. A method of drying blood, which comprises subjecting blood to pH treatment for neutralizing with an alkali after adding an acid, heat denaturing treatment, and then drying.