JPH0829069B2 - Method for producing sterilized blood meal having gel strength - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION “Industrial field of application” The present invention relates to a blood meal sterilized by heating from a blood component having a gel strength such as plasma or serum obtained from animal blood without impairing the gel strength. The present invention relates to a method for producing blood meal that can be obtained.

"Prior art and problems" As is well known, blood of slaughtered cows, pigs, etc. has high protein content,
It is low in fat, and the amino acid composition contained in the protein is nutritionally excellent.

However, looking at the blood utilization status of such slaughtered animals, only a small portion of low quality was produced by a simple treatment method such as boiling coagulation, and it is only used for fertilizer or feed. However, most of the wastewater is treated as unused, which presents a heavy burden on wastewater treatment.

Therefore, in recent years, from the standpoint of effective utilization of by-product substances of livestock animals and modernization of slaughterhouses, in addition to the excellent nutritional value of blood components, it is possible to make good use of various physical properties such as foods that have excellent blood components. As a blood treatment method, centrifuge the blood to separate the blood into blood cells and plasma, or remove fibrin from the blood and centrifuge the blood to separate into blood cells and serum, and spray-dry each separated. There is provided a method for obtaining blood meal, which is a dried product, without denaturing proteins by low temperature drying such as freeze-drying and vacuum drying.
Among the blood meal obtained by this method, for example, plasma or serum,
It has a pale yellow color, and the gel strength is in the state of dry blood powder,
For example, 300 g / cm ² or more for pig plasma and 500 g / cm ^{2 for} bovine plasma.
As described above, it is possible to be an additive for foods which are originally considered important for viscoelasticity, strain, and texture. For example, it can be effectively used as a substitute egg white or the like.

However, in the above-mentioned conventional method, since the concentration and drying temperature is low, sterilization by temperature is not considered, and the obtained plasma or serum product has a large number of general viable bacteria of about 10 ⁵ to 10 ⁷ per 1 g. In many cases, the number of heat-resistant spores was more than 10 ³ cells / g, and the number of coliforms was also positive, so there was a problem in food safety.

When blood meal is used as a food or a processed material such as a food or a medicine, the most important point is contamination with microorganisms.
For that purpose, it is necessary to adopt a hygienic blood sampling method in the blood sampling step of obtaining the raw material of blood powder, and also in the subsequent separation and drying step, the contamination of microorganisms from the outside and the growth of microorganisms in the step are required. It is important to suppress it as much as possible. However, it is difficult to completely suppress these microorganisms in the manufacturing process.

Therefore, it is important to sterilize the obtained blood powder,
One known method for sterilizing blood powder is gas sterilization with ethylene oxide, propylene oxide, or the like. This sterilization method is capable of sterilization without causing protein denaturation and deterioration of blood powder solubility and gel strength, but the problem of residual toxicity of the used gas remains unsolved. Another sterilization method is a heat sterilization method. Although this sterilization method is an excellent sanitary sterilization method, it causes heat denaturation of proteins, lowers gel strength, and causes a significant decrease in commercial value of blood meal.

By the way, prior to the present invention, the present applicant has found that blood components such as blood or plasma are soluble in water (solubility).
And a method for obtaining a sterilized dry product without lowering the heat coagulability by more than 50% (Japanese Patent Publication No. 60-15). In this method, blood or each blood component separated by a centrifuge or the like is dried at a low temperature to obtain a dry product having a water content of 30% by weight or less, and the dry product is 80 to 16% for each water content.
Although it is heated to a temperature of 0 ° C. and sterilized, the gel strength, which is a physical property as an additive for which viscoelasticity, strain, and texture are important, was not considered.

Gel strength is a phenomenon different from solubility (water solubility) and thermocoagulability. For example, blood cells have a reddish brown color and have a nutritionally excellent composition similar to plasma and serum. Seen in terms of dry matter, about 90% and 70 of plasma and serum
Excellent compared to ~ 75%. However, blood cells originally do not have gel strength, and even if they can maintain solubility and thermocoagulability when obtaining a dry product of plasma or serum, the product obtained by heating and coagulating the dry product is shabby and soft. It is often impossible to measure gel strength. Even if the solubility can be maintained at about 80% when obtaining a dry product, the gel strength will be greatly reduced.

The gel strength referred to here is one that is generally used as a measure of fracture strength when a sample is compressed,
Sometimes called jelly strength. Next, the outline of the method for measuring the gel strength will be described.

First, blood powder is dissolved in distilled water to prepare a solution having a solid content of 10%. This is filled in a vinylidene chloride tube having a diameter of 30 mm, and degassing is performed from the upper part of the tube with a vacuum pump. The tube is then sealed and placed in a hot water bath at a temperature of 90 ° C for 30
Heat to solidify for minutes. After heating and solidifying, the mixture is cooled to 15 ° C, the vinylidene chloride tube is peeled off, and the breaking point of a cylindrical sample cut into a length of 30 mm is measured using a rheometer. In the experimental example described later, NRM-2 manufactured by Fudo Kogyo Co., Ltd.
002J, a disk type plunger (for viscoelasticity) with a diameter of 1.5 cm was used as an adapter. The measurement is performed 5 times for each sample, the average value of the 3 measured values is calculated excluding the highest value and the lowest value, and the gel strength is calculated by the following formula.

The load scale of the measuring instrument NRM-2002J is displayed in percentage, and the load at 100% can be switched. Therefore, the above equation is also displayed as

The present inventors, as a result of various studies in view of the above circumstances,
The dried blood component (blood powder) having gel strength such as plasma and serum obtained by the low temperature drying is contacted with superheated steam at 120 to 180 ° C. in an initial water content of 3 to 12% by weight, and After maintaining the state of complete contact with the dried blood component for 5 to 20 seconds, the superheated steam and the dried blood component are separated, and immediately after the separation, the dried blood component is cooled to 110 ° C or less, and the gel strength is almost the same. It was found that it does not decrease and is effective for sterilization of not only general viable bacteria and coliform bacteria but also thermostable spores.

The present invention has been made based on the above findings, and an object thereof is to sterilize general live bacteria of blood powder, Escherichia coli, and heat-resistant spore bacterium (commercial sterilization) with almost no decrease in gel strength. There is provided a method for producing blood powder capable of "Means for solving problems" The method for producing blood powder having gel strength according to the present invention,
The initial water content obtained from blood has a gel strength of 3 to 12% by weight.
ted steam), and the state of complete contact between the superheated steam and the dried blood component is maintained for 5 to 20 seconds, then the superheated steam and the dried blood component are separated, and immediately after the separation, the dried blood component is heated to 110 ° C. The method is characterized by cooling below.

[Operation] According to the above method, it is possible to sufficiently sterilize the dry blood component having gel strength such as dry plasma and dry serum obtained by low-temperature drying without substantially lowering the gel strength.

 Hereinafter, the present invention will be described in detail with reference to examples.

[Example] As shown in FIG. 6, blood is collected from the domestic animal 1 in a hygienic manner with a tubular knife or the like, and at the same time, an anticoagulant such as an aqueous solution of sodium citrate in the anticoagulant tank 2 is immediately applied to the blood. For example, about 0.5% by weight of sodium citrate is mixed to prevent blood coagulation. The collected blood is temporarily stored in the inspection tank 4 after removing contaminants such as meat pieces, fat pieces, and hair mixed through the strainer 3. After checking the presence or absence of slaughter of illness by inspecting the carcass while storing it in the inspection tank 4, only blood confirmed to be hygienic was passed through the next heat exchanger 5 and cooled. Then, it sends to the centrifuge 6. Separation is performed by this high-speed continuous centrifugal separator 6,
The light fluid portion is collected as plasma fluid and the heavy fluid portion is collected as blood cell fluid.
The obtained plasma liquid is sent to the next plasma vacuum low-temperature dryer 7, where the product temperature is preferably 40 ° C when the plasma liquid concentration is low.
Below, care should be taken to prevent heat denaturation of the protein in the plasma solution by drying at a low temperature while keeping the product temperature at 50 ° C or lower even when the concentration becomes as high as 50% by weight or more. As for the degree of drying in the vacuum low temperature dryer 7, the degree of drying is adjusted in consideration of the sterilization step of the next step, and the drying is stopped at an appropriate moisture step. The dried plasma powder is pulverized by a pulverizer 8 to a size of usually 60 mesh under.

When obtaining dried serum instead of dried plasma, gently remove the fibrin in the blood by squeezing the capture element, etc. from the blood in the blood, and then separate it into serum and blood cells with a centrifuge. Alternatively, the plasma liquid separated by the centrifuge is stored in a storage tank for a while, the fibrin is coagulated, and the coagulated fibrin is removed by sieving, filtering or a strainer to obtain a serum liquid, and the serum is obtained. The liquid may be dried in a vacuum low temperature dryer as described above.

The above-mentioned dried plasma and dried serum correspond to the dried blood component of the present invention.

In order to effectively carry out the present invention, common sense precautions regarding the handling of foods containing protein in the blood collection step, separation step and drying step before the sterilization step, which is the next step, are important. That is, when collecting blood, be careful not to mix microorganisms into the blood as much as possible, and after cooling blood, perform sufficient cooling, preferably at 4 ° C or lower to prevent growth of microorganisms in blood after collecting blood. Is important. Further, in the separation step, the temperature of the blood rises in the centrifuge, so it is preferable to cool it again to 4 ° C. or lower in a storage tank (not shown) that stores the separated liquid. In the drying process, it is necessary to heat both plasma and serum in order to evaporate water, but at this time, keep the product temperature at 50 ° C or lower, preferably 40 ° C or lower, and keep it at a temperature at which protein denaturation occurs. It is necessary to avoid going up as much as possible. The plasma and serum liquids have a low solid content of about 8% by weight before the start of drying, but the lower the concentration, the more easily protein denaturation occurs due to temperature. It is better to keep the product temperature as low as possible up to the concentration.

Dry plasma and dry serum, which are dry blood components produced as described above, have a solubility of 90% or more, and the plasma powder gel strength is 500 g / cm ² or more in the case of bovine and in the case of pig. It is 300 g / cm ² or more, which is slightly different depending on the type of slaughtered but has a high value and is an extremely excellent intermediate product in terms of physical properties. However, in terms of the number of microorganisms, blood meal is roughly
In many cases, it contains a large amount of microorganisms of about 10 ⁵ to 10 ⁷ per 1 g.

Subsequently, the above-mentioned dried plasma and dried serum are put into the heat sterilizer 9 which is in direct contact with superheated steam. The heat sterilization referred to here is commercial sterilization (Commercial Sterili
zatoin) is included. That is, without significantly reducing the gel strength, which is a very important physical property as the commercial value of dried plasma and dried serum, commercial sterilization is performed to reduce the number of general viable bacteria, the number of heat-resistant spores, and the number of coliforms, and is hygienic.
It also includes the production of blood meal having excellent gel strength.

Regarding the degree of commercial sterilization, the microbiological component standards of foods stipulated by the Food Sanitation Law are referenced, but there are differences in the allowable number of bacteria depending on the type and composition of foods and each stage of the manufacturing process. . In this example, the number of general viable bacteria, the number of heat-resistant spore bacteria and the number of coliform bacteria are reduced, preferably food according to the Ministry of Health and Welfare Ordinance No. 58 and the Ministry of Health and Welfare Notification No. 221 of December 19, 1984,
With the revision of the standards for food additives, etc., the number of general viable bacteria listed as a voluntary inspection standard for those with a sterilization process in “Handling at the 3rd blood processing facility” in Attachment 3 of the notification on January 18, 1985, 10 ⁴ / g or less, heat-resistant spore count 3000
Per g / g, number of coliforms; aiming at negative level or less, preferably 300 viable bacteria / g or less, heat-resistant spores less than 20 g / g, number of coliforms is the most accurate method (MPN method)
The goal is to reduce the amount to 30 / 100g or less.
In addition, the general viable cell count below 300 / g, heat-resistant spore count below 20 / g, coliform count below 30 / 100g (MPN method)
Is what is expressed as negative as a convention for counting the number of bacteria in food.

The main items of the technical constitution of this sterilization step are appropriate product temperature during heat sterilization, maintenance of time, and adjustment of initial water content of the dried blood component which is the substance to be sterilized. Hereinafter, each of these items will be described in detail.

(I) Temperature of Superheated Steam The temperature of the superheated steam used during sterilization is appropriately 120 to 180 ° C, preferably 140 to 160 ° C.

The numbers of general viable bacteria, heat-resistant spores, coliform bacteria, etc., contained in the dried blood component vary considerably depending on the season, the blood collection method, the equipment and operation until the dried blood component is collected. For example, the number of heat-resistant spores increases because the spore-forming bacterium forms spores when the storage time of plasma or serum increases. In addition, the general viable cell count and coliforms are at a lower concentration than blood cell fluid if the carcass is not sufficiently washed during blood sampling or the temperature of the blood plasma or serum fluid is high. There is a significant increase in proliferation during storage.

The difficulty of sterilization of dried blood components depends on the number of microorganisms, but is more dependent on the difference in the type of bacteria. Generally, as the number of microorganisms increases, it is more difficult to sterilize up to a predetermined bacterial count level,
In addition, thermostable spores are difficult to sterilize by overheat sterilization. If the number of microorganisms in these dried blood components is low, and if the microorganisms are easy to sterilize, even if overheated steam at about 120 ° C is sufficient in some cases, the number of microorganisms is large,
And for microorganisms that are difficult to sterilize, superheated steam at about 180 ° C may be required. When the temperature of superheated steam rises,
The bactericidal effect is excellent, but the gel strength is greatly reduced, which is not preferable in terms of quality. The temperature of superheated steam depends on the number of microorganisms,
Although it depends on the difficulty of sterilization depending on the type of microorganism, it is preferably 140 to 160 ° C in consideration of the decrease in gel strength.
When setting the temperature of superheated steam, it is important to reduce the deterioration of quality as much as possible and meet the purpose of commercial sterilization.

The pressure of supersaturated steam is 0.3 to 0.4 Kg / cm ^{2 in} gauge pressure when using superheated steam of 140 to 160 ° C. in the above apparatus. The range of pressure of superheated steam is not particularly limited, but since there is a slight temperature drop in the main body of the sterilizer, it is necessary to set the pressure taking into consideration the enthalpy of the superheated steam so as not to saturate the superheated steam. It is necessary to use superheated steam having a superheat degree (dryness) as high as possible. As a method for preventing saturation, it is necessary to adjust the amount of blood powder filled in the sterilizer in addition to setting the pressure.

As a problem due to saturation of superheated steam, in addition to the influence on the gel strength due to the fluctuation of the water content of the dried blood component, there is adhesion of sterilized dried blood component (blood powder) to the pressure-feeding pipe due to dew condensation. There is a concern that microbial growth may be contaminated again at the adhesion site.

ii) Initial water content of dried blood components The initial water content of dried blood components is closely related to the bactericidal effect and gel strength. The higher the initial water content, the better the bactericidal effect, but on the other hand, the gel strength decreases and the physical properties decrease. It is not preferable.

In the case of the present invention in which superheated steam is directly contacted for a short time,
The physical properties are less affected than when sterilized by indirect heating for a long time, but the initial moisture content affects the gel strength and sterilization effect. The bactericidal effect cannot be mentioned. The range of initial water content at which effective sterilization can be carried out without causing a decrease in gel strength is 3 to 12% by weight, preferably 4 to 10% by weight, more preferably around 7% by weight.

When the water content of the dried blood component is 3% by weight or less, it is desirable to carry out spray humidification, thoroughly agitate and mix to humidify to a predetermined water content, and then perform heat sterilization.

In addition, in this specification, the water content is a value represented by the following equation.

Regarding the adjustment of the upper limit value of the initial water content suitable for sterilization, it is preferable to control in the dryer and stop the drying when the water content of the blood powder reaches the target value. From the viewpoint of such difficulty of adjusting the dry water content, the low temperature vacuum dryer is easier to adjust than the spray drying (spray dryer). In order to effectively carry out the present invention, it is important to consider the pretreatment process as described above.

Plasma liquid and serum liquid have a solid content of about 8% by weight (water content: 92% by weight), although there are some differences depending on the type of animal, season, and the like. When drying plasma and serum, keep the product temperature at a low concentration stage (water content of 50% by weight or more) low.
It is important to prevent the gel strength from decreasing in the drying stage and stop the drying with an appropriate water content for the next sterilization step.

(Iii) Particle size of blood powder As a method for drying plasma liquid or serum liquid that is a blood component having gel strength, a spray dryer or a stirring type vacuum dryer is used, but these are dried blood powder (dry (Blood component) has irregular particle size,
From the viewpoint of the bactericidal effect, it is preferable that the dried blood component be crushed in advance, crushed to 60 mesh under and then sterilized. If crushed after sterilization, the blood powder after sterilization may be contaminated by microorganisms again by the crushing operation, and if the particle size of blood powder is too large, the amount of heat transfer to the inside will be small and the effect of sterilization may not be good. . It is difficult to adjust the particle size of dried blood powder depending on the type of dryer, and in the case of a spray dryer, it is possible to adjust the particle size to a considerably finer size by adjusting the rotational speed of the rotating disk and the nozzle particle size. However, in the case of a vacuum low-temperature dryer, the particle size of dried blood powder is generally uneven. When the particle size of dried blood powder becomes large, heat transfer to the inside of the particle becomes poor, and it is necessary to raise the temperature of superheated steam or lengthen the time of direct contact in order to perform sufficient sterilization. The decrease of is large. In order to eliminate such defects, it is preferable to pulverize it to 60 mesh or less for sterilization.

(Iv) Cooling after sterilization In the method of the present invention, the dried blood component is directly supplied to the main body of the heat sterilizer and then directly contacted with superheated steam at 120 to 180 ° C, usually around 150 ° C. Since sterilization is performed, the heat transfer effect is extremely good, and the product temperature of the dried blood component reaches a point almost close to the temperature of superheated steam. Since sterilization by complete contact with superheated steam is completed in a very short time of 5 to 20 seconds, keeping dry blood components at such a high temperature thereafter causes a decrease in gel strength. Sterilization is performed very quickly under high temperatures such as the temperature of the superheated steam used, but the gel strength decreases rapidly, so immediately after the sterilization, the gel strength does not decrease immediately. There is a need to.

As a result of various investigations on the temperature at which the gel strength does not decrease, the inventors of the present invention immediately cool it to 110 ° C. or lower and transfer it to a large container, etc. We came to find that the decrease was hardly observed. However, it should be noted that if the dried blood component is kept in a small container after sterilization, the gel strength is affected even at 110 ° C due to the effect of water vapor generated from the dried blood component. The condition of 110 ° C. or less for standing cooling is a standard of the cooling temperature in consideration of means for releasing water vapor generated by opening or ventilation. As a treatment of dried blood components after sterilization, it is ideal to immediately cool to near room temperature. Using the device of FIG. 1 described later,
Good results have been obtained by passing tap water through the jacket of the cooler and cooling to a product temperature of about 40 to 50 ° C. within 1 to 2 minutes after the sterilization is completed.

By sterilizing dried blood components according to the above technical elements, it is possible to achieve the purpose of commercial sterilization, suppress the decrease in gel strength as much as possible, and add value as an excellent food or processing raw material such as food. It is possible to produce high blood meal.

The present invention is an excellent method in that it is possible to sterilize thermostable spores that cannot be obtained by indirect heat sterilization, and the degree of gel strength reduction is smaller than that of indirect heat sterilization.

Here, the configuration of specific examples of a direct heating sterilizer using various superheated sterilization steams suitable for use in the method for producing a sterilized blood powder having gel strength according to the present invention outlined above, and various devices attached thereto Will be described with reference to the drawings.

As shown in FIG. 1, the direct heat sterilizer 9 is a sterilizer main body.
A heating jacket is provided on the outer circumference of 9a, and a hollow shaft 9c having a stirring blade 9b is rotatably installed in the sterilizer body 9a so that one end of the hollow shaft 9c is rotated by a motor 9d. It is composed. A fixed quantity feeder 10 for supplying the dry plasma or the dry serum is connected to an upper end (upper right part in FIG. 1) of the sterilizer main body 9a. A large number of small holes for jetting air or superheated steam are formed on the outer periphery of the hollow shaft 9c, and the superheated steam supply pipe 11 is connected to the other end of the shaft 9c via a rotary joint. . A heater 11a for preventing a decrease in steam temperature is wound around the superheated steam supply pipe 11, and the supply pipe 11 includes a valve 12
Is connected to the super heater 13 via. A steam supply pipe 33 having a valve 17 is connected to the super heater 13. The steam supply pipe 33 has a valve 17
A bypass pipe 34 is provided in front of and behind, and a small flow valve 35 is attached to the bypass pipe 34. Further, between the valve 17 of the steam supply pipe 33 and the super heater 13, an air supply pipe 36 having a sterilization air filter 14, an air heater 15 and a valve 16 is connected.

Further, a discharge valve 19 which is opened and closed by an air cylinder 18 is attached to the lower part of the other end of the sterilizer main body 9a (lower left part in FIG. 1), and the discharge port of the discharge valve 19 is an air transfer pipe 20. Are linked to. The upstream end of the air carrying pipe 20 is divided into two parts, and one is provided with a superheated steam supply pipe between the super heater 13 and the valve 21 via a valve 21.
The other end is connected to the air supply pipe 36 between the air filter 14 and the air heater 15 via a valve 22. The downstream end of the air transfer pipe 20 is connected to the cyclone 23. A cooler 25 is connected below the cyclone 23 via a cushion tank 24, and a vent cyclone 26 is connected above the cyclone 23 via a pipe.

Further, a settling tank 27 with a jacket for indirect steam heating is attached to the upper end (upper left part in FIG. 1) of the main body 9a of the sterilizer. At the top of this settling tank 27 is a valve 28.
This is connected to a pipe 29 with a heater that has
The other end of 29 is connected to the vent cyclone 30. A bypass pipe 31 is provided in front of and behind the valve 28 in the heater-equipped pipe 29, and a small flow valve 32 is attached to the bypass pipe 31.

Incidentally, reference numeral 37 is a drain pipe branched from the superheated steam supply pipe 11 between the sensor of the temperature control device TC of the super heater provided on the outlet side of the super heater 13 and one connection point of the air transfer pipe 20, A drain valve is installed. Reference numeral 38 is an air discharge pipe branched from the air supply pipe 36 between the air heater 15 and the valve 16, and an exhaust valve is interposed.

In the above structure, first, the water 3 which is a dried blood component
About 12% by weight of dry plasma and serum enter the quantitative feeder 10 from the raw material hopper (not shown), open the supply valve of this quantitative feeder 10, and set a fixed amount (about
About 1kg) is directly supplied to the heat sterilizer. At this time, the valve 28 of the pipe 29 is open, and the inside of the sterilizer main body 9a is at atmospheric pressure. Further, the pipe 29 is heated by the heater, and the super heater 13 is supplied with only the air preheated by the air heater 15 after being sterilized by the air filter 14 through the air supply pipe 36. The hot air from the super heater 13 passes through the valve 21, the air transfer pipe 20, the cyclone 23, and the vent cyclone 26.
Is discharged through the pipes, and the respective pipes are heated and washed.

After the supply of the raw material is completed, the shaft 9c of the direct heat sterilizer 9 is rotated, the stirring blade 9b is rotated at a low speed to diffuse inside the main body 9a of the sterilizer, and the dried blood component is preheated on the inner wall with the heating jacket. The dried blood component moves along the inner wall of the sterilizer while being dispersed by the rotation speed of the stirring blade 9b, so that it is preheated with a good heat transfer effect. Due to the heat transfer coefficient, the steam in the heating jacket is usually saturated steam (about 100 to 1
20 ° C) is used and the dried blood components are preheated to about 40-110 ° C. In this way, the diffusion and preheating of the dried blood component is performed for about 5 seconds. At this time, the super heater 13 is connected to the steam supply pipe via the small flow valve 35 of the bypass pipe 34.
It is switched so that only a small amount of steam is supplied from 33, and the superheated steam superheated by the super heater 13 is prepared to be discharged only through the drain pipe 37.

When the vapor diffusion and preheating are completed, the rotation of the stirring blade 9b is stopped, and then the valve of the superheated vapor supply pipe 11 is closed.
12 is opened and the superheated steam from the super heater 13 passes through the small hole in the shaft 9c for a certain time (5 to 10 seconds)
While being sent inside the sterilizer body 9a,
The dry air in 9a is discharged from the pipe 29 via the settling tank 27, the valve 28 and the vent cyclone 30, and the dry air in the sterilizer main body 9a is replaced with superheated steam. In this case, since the drain pipe of the drain pipe 37 is still open, the flow rate of the superheated steam flowing into the sterilizer body 9a does not become so high, and the sedimentation tank 27 also causes the dried blood components in the sterilizer body 9a to flow. Does not flow into the pipe 29.

After the gas replacement inside the sterilizer body 9a is completed, the valve 2 of the pipe 29
8. Close the small flow valve 35 of the bypass pipe 34 and the drain valve of the drain pipe. Next, the shaft 9c of the direct heating device 9 is rotated, the stirring blade 9b is rotated at a high speed, and the valve 17 of the steam supply pipe 33 is opened.
Superheated steam is supplied into the sterilizer main body 9a from 13 to perform sterilization. The dried blood component is 120 due to the rotating action of the stirring blade 9b.
It makes good contact with superheated steam at ~ 180 ° C for instant sterilization. The pressure in the main body 9a of the sterilizer at this time is preferably 0.2 to 0.4 kg / cm ² , and the time required for sterilization is 5 to 20 seconds, preferably 10 to
15 seconds. This sterilization required time corresponds to the time of the complete contact state between the superheated steam and the dried blood component of the present invention.

After this direct heat sterilization, if left at the same temperature for a long time, the blood powder undergoes heat denaturation and loses its gel strength. Therefore, it is immediately cooled by the following operation. That is, after the completion of direct heat sterilization, in order to prevent the loss of dried blood components, the valve 17 of the steam supply pipe 33 and the valve 12 of the superheated steam supply pipe 11 are closed to supply the superheated steam into the sterilizer main body 9a. Then, the rotation of the stirring blade 9c is stopped, and the operation of releasing the internal pressure by the small flow valve 32 above the settling tank 27 is performed (about 10 seconds). During this time, preheated air is supplied to the super heater 13 via the air filter 14 and the air heater 15, and high temperature air from the super heater 13 is sent to the air transfer pipe 20 via the valve 21. The air carrier pipe 20 is prepared to be heated and washed and immediately supplied to the sterilizer main body 9a.

Then, after depressurizing the sterilizer main body 9a, the air transfer pipe
The valve 21 of 20 and the small flow valve 32 of the bypass pipe 31 are closed, the valve 12 of the superheated steam supply pipe 11, the exhaust valve of the air exhaust pipe 38 and the valve 28 of the pipe 29 are opened, and high temperature air from the super heater 13 is opened. It is fed into the sterilizer main body 9a for about 10 seconds and discharged through the sedimentation layer, the pipe 29, and the vent cyclone 30. This replaces the superheated steam in the sterilizer body 9a with dry air. The flow velocity of the hot air (dry air) flowing into the sterilizer main body 9a is low because the exhaust valve of the air exhaust pipe 38 is open, and the settling tank 27 causes the dry blood component in the sterilizer main body 9a to be piped. Never flow into 29.

After that, the exhaust valve of the air exhaust pipe 38 and the valve 28 of the pipe 29 are closed, and the exhaust valve 19 of the direct heat sterilizer 9 is opened to remove the air filter 14 for sterilization and the air heater.
15, high temperature dry aseptic air is sent into the sterilizer main body 9a via the super heater 13, and the sterilized dry blood components inside are cyclone 23 while rotating the stirring blade at low speed (about 100 rpm). , And is pressure-fed to the cooler 25 via the cushion tank 24. Gas-solid separation is performed in the cyclone 23, and hot air and slightly entrained superheated steam are removed from the blood powder. The cooler 25 is equipped with a stirrer similar to a direct heat sterilizer, and the dry blood component is pressed by a blade of a stirring blade at a rotation speed of about 200 rpm against the inner wall with a cooling water jacket in a thin layered form from the inlet side to the outlet side. Move to. The sterilized and cooled dried blood component is sent to the product hopper (not shown) by the discharge valve of the cooler 25.

The gel strength of dried plasma and dried serum is very delicate and easily deteriorates depending on the heating time and the heating temperature, and normally these operations are automatically controlled.

FIG. 2 shows another structural example that can be used in place of the direct heat sterilizer. In the figure, a super heater 42 for converting steam from a steam generator (boiler) 41 into superheated steam is provided at the end of the sterilization tube 40, and the sterilization tube 40 near the super heater 42 is provided with dry blood. A hopper 43 having a charging valve 43a for charging the components into the sterilization pipe 40 is provided. At the other end of the sterilization pipe 40, a separator (cyclone) 44 for separating superheated steam and sterilized dry blood components is provided. The distance between the charging valve 43a and the separation device 44 is determined according to the sterilization time in which the dry blood component is charged into the air stream of the superheated steam, floats in the airflow, and is separated from the superheated steam. . The separation device
A discharge valve 44a is provided below 44. The input valve 43a and the discharge valve 44a have a mechanism for preventing leakage of superheated steam, and generally rotary valves are used. The outer circumference of the sterilization pipe 40 is kept warm in order to prevent condensation of superheated steam. A circulation blower 45 for reusing the used superheated steam is provided on the discharge side of the separation device 44 as needed to save energy, and the circulation blower 45 is connected to the super heater 42. The discharge valve 44a is connected to substantially the center of the transport pipe 46, and an air heater 47, a blower 48, and a blower 48 are sequentially provided at the upstream end of the transport pipe 46.
An air filter 49 is connected, and the downstream end is connected to a separating device (cyclone) 50. Another separating device 52 is connected to the upper part of the separating device 50 via a discharge pipe 51,
Discharge valve (rotary valve) under the separator 50
50a is connected upstream of the cooling pipe 53. A blower 54 and an air filter 55 are sequentially connected to the upstream end of the cooling pipe 53, and a separator (cyclone) 56 having a product discharge valve 56a is connected to the downstream end.

In the above configuration, the steam generated by the steam generator 41 is heated by the super heater 42 to become superheated steam, which is then fed into the sterilization pipe 40 as an air stream. On the other hand, the preheated dry blood component is introduced into the sterilization tube 40 via the introduction valve 43a. The introduced dry blood component is sterilized by heating while floating in the air stream, transferred to the separation device 44, and separated from the superheated steam.
The flow rate of the superheated steam in the sterilization pipe 40 is required while the dried blood components are suspended in the separation device 44 by a regulating valve (not shown) provided before and after the super heater 42 or a circulation blower 45 provided as necessary. It is adjusted to obtain a long sterilization time. Generally, 10 m / sec to 30 m / sec is preferable, although it varies depending on the amount of the dried blood component supplied. Exhaust valve 44
The sterilized dry blood component discharged from a is blower 4
Aseptic hot air sent by 8 is sent to the separating device 50 through the transport pipe 46. The dried blood component separated by the separation device 50 is cooled by sterile air sent by the blower 54, separated by the separation device 56, and discharged from the product discharge valve 56a to become product blood powder.

By passing through the steps of the superheated steam → hot air (air) → cool air (air), the superheated steam that has been entrained in the transport pipe 46 is prevented from condensing, and the superheated steam is prevented from being entrained in the cold air.

The cooling pipe 53 and the separating device 56 may be replaced with the cooling device 25 shown in FIG.

In order to increase the heat transfer efficiency by increasing the relative speed between the superheated steam or cold air and the dried blood component in the sterilization pipe 40 and the cooling pipe 53, for example, as shown in FIG. The central axis of the inlet portion 60a is the tube 60
Of the pipe 60 so that the flow at the inlet portion 60a is tangential to the cross section of the pipe 60, and a jacket 61 is provided to flow the heat medium to indirectly heat or cool the heat medium. Alternatively, as shown in FIG. 3 (b), fixed blades 63 having inclined blades may be attached to the flow passage in the pipe 62 at regular intervals to give a swirl flow to the superheated steam.

Further, instead of the sterilization pipe 40 and the cooling pipe 53, a drop type device shown in FIG. 4 or a fluidized bed type device shown in FIG. 5 can be used.

Explaining the case where these devices are used as a sterilizer, in the device shown in FIG. 4, a rotary vane type agitator 71 is provided above the inside of the heating can 70, and a raw material inlet 72 is provided at the top, A product discharge port 73 is provided at the lower part, and the superheated steam from the super heater 74 is sent from the lower part of the heating can 70 by the blower 75 and discharged from the upper part. The device shown in FIG. 5 is a super heater.
The superheated steam of 80 is fed by a blower 81 into a fluid heating device 82 having a special structure, and the raw material hopper 83 is fed into the superheated steam flow discharged from the fluid heating device 82 to feed the preheated raw material. The cyclone 84 separates the superheated steam from the superheated steam and inputs it into the flow heating device 82. The flow heating device 82 has a raw material inlet 82a and a superheated steam outlet 82b in the upper part, a superheated steam inlet 82c and a product outlet 82d in the lower part, and a horizontal partition wall 82e having a porous portion in the center of the inside. A plurality of rotary blades 82f that are provided and are in sliding contact with the partition wall 82e are attached, and the raw material charged from the raw material input port 82a is moved by the rotary blades 82f and discharged at the missing portion of the horizontal partition wall 82e. The device is configured to be taken out from the discharge hopper 82g through the product outlet 82d when reaching the hopper 82g.

When the device is used as a cooler, the super heaters 74 and 80 may be omitted, and cool air may be introduced into the device by a blower instead of superheated steam.

Blood meal sterilized as described above can
Bagging is performed by a bagging machine 91 shown in the figure. In FIG. 6, reference numerals 92, 93, 94, 95, and 96 respectively represent a vacuum low-temperature dryer, a crusher, a sterilizer, a cooler, and a bagging machine for blood cell fluid.

Next, an example carried out to confirm the effects of the above example will be described.

(Experimental Example 1) As an experimental sample, a particle size of 60 mesh under before sterilization obtained in the manufacturing process shown in FIG. 6, water-soluble about 99%, dry plasma with a gel strength of about 650 g / cm ² or more, cattle A sterilization test was conducted using the dried serum and the direct heat sterilizer shown in FIG.

1 kg of dried plasma or dried serum was supplied from the quantitative feeder 10 into the sterilizer main body 9a. The internal volume of the main body 9a is 300 × 20
It has a size of 00 mH and a volume of about 140 l. The operation procedure of this device is as follows: supply of raw material, diffusion of sample in main body 9a, replacement of gas with superheated steam, sterilization by complete contact of superheated steam, depressurization, replacement of gas with high temperature sterile air, discharge and cooling of sample. 1 cycle is a process of about 2 minutes, sterilization by complete contact of superheated steam is 10 seconds, pressure of superheated steam is 0.3 kg / cm ² · G, temperature of superheated steam is changed After sterilization, the gel strength of dried plasma and dried serum and the number of microorganisms were examined. The test results are shown in the following Table 1 (dry plasma) and Table 1 (dry serum).

As is clear from Table 1 and Table 2, the bactericidal effect is improved as the temperature of the superheated steam increases, but the gel strength tends to decrease. The upper limit of the sterilization temperature is about 180 ° C when judged from the viewpoint of maintaining gel strength, and the lower limit of the sterilization temperature is judged to satisfy the microbial component standard, 12
It is about 0 ° C. Furthermore, when the number of general viable bacteria is set to 300 cells / g or less and the gel strength is judged with a slight margin, a preferable temperature range is approximately 140 to 160 ° C.

For the above reasons, the temperature range of superheated steam is 120 to 180 ° C.
Therefore, the temperature is preferably 140 to 160 ° C.

(Experimental Example 2) The test results of the influence of the initial water content of dried plasma and serum on the quality of the product after sterilization are shown below. As the sample, dried pig plasma and dried serum obtained in the same manner as in Experimental Example 1 were used. This sample was made under 60 mesh and prepared with several points of water content of 2 to 14% by weight, and a sterilization test was conducted using the direct heating type sterilizer shown in FIG.

"Operating conditions of direct superheat sterilizer" ・ Sample filling amount ・ ・ ・ ・ ・ 1kg ・ Superheated steam temperature ・ ・ ・ ・ ・ 150 ℃ ・ Superheated steam pressure ・ ・ ・ ・・ 0.3kg / cm ²・ G ・ Main body heating saturated vapor pressure ・ ・ ・ 1.0kg / cm ²・ G (heating jacket) (about 120 ℃) ・ Sterilization time by complete contact with superheated steam
・ ・ ・ 10 seconds ・ 1 cycle time ・ ・ ・ about 2 minutes ・ Sample cooling temperature after sterilization ・ ・ ・ 40 to 50 ℃ ・ Initial moisture ・ ・ ・ 2,3,4,6, 8, 10, 12, 14
(Wt%) The experimental results are shown in Table 3 (dry plasma) and Table 4 below.
(Dry serum).

As is clear from Tables 3 and 4, the bactericidal effect improves as the initial water content increases, but the gel strength tends to decrease.

The upper limit value of the initial water content is about 12% when judged from the viewpoint of maintaining gel strength, and the lower limit value is about 3% when judged from the viewpoint of satisfying the microbial component standard, and 2% is not preferable. Furthermore, when the general viable cell count is set to 300 cells / g or less and the gel strength is judged with some allowance, a preferable initial moisture range is about 6 to 8%.

As is clear from Experimental Examples 1 and 2, both dried plasma and dried serum can be sterilized under substantially the same conditions. In terms of difficulty of sterilization by type of microorganism, heat-resistant spore bacterium is more difficult than general live bacteria and coliforms, and according to the method of the present invention, sterilization of heat-resistant spore bacterium is also possible, but heat-resistant spore bacterium Since there is a slight deterioration in quality under the conditions of sterilization, it is necessary to take measures such as shortening the retention time of plasma and serum in the production process so that spores are not formed as much as possible.

(Experimental Example 3) A test example in which the relationship between the contact time with superheated steam and the gel strength and the number of microorganisms was investigated is shown below.

A major factor affecting the sterilization effect is the temperature of superheated steam and the contact time. In this experimental example, the complete contact time with superheated steam (= sterilization time) was examined. In this experimental example, a sterilization experiment was carried out using dried pig plasma and dried serum obtained in the same manner as in Experimental Example 1. The sterilization device used in the experiment is the same device used in Experimental Example 1.

The experimental conditions are shown below.

"Operating conditions of sterilizer" ・ Sample filling amount ・ ・ ・ ・ ・ ・ ・ ・ 1kg ・ Sample particle size ・ ・ ・ ・ ・ ・ 60 mesh under ・ Superheated steam temperature ・ ・ ・ ・ ・ ・ 150 ℃ ・ Superheated steam pressure ・ ・ ・ ・ ・ ・ ・ ・ 0.3kg / cm ²・ G ・ Main body heating saturated steam pressure ・ ・ ・ 1.0kg / cm ²・ G (heating jacket) (about 120 ℃) ・ Superheated steam Sterilization time by full contact of
3, 5, 10, 15, 20, 25 (sec) ・ 1 cycle time ・ ・ Approximately 2 minutes ・ Sample cooling temperature after sterilization ・ ・ ・ 40 to 50 ℃ ・ Initial water content ・ ・ ・7 wt% Experimental results are shown in the following Table 5 (dry plasma) and Table 6 (dry serum).

As is clear from Table 5 and Table 6, if the sterilization time is extended, the bactericidal effect is improved, but the gel strength tends to decrease.

The upper limit of the sterilization time is, from the viewpoint of maintaining the gel strength, about 20 seconds, and at this point it is barely possible to keep the gel strength at 300 g / cm ² , and the gel strength becomes 25 seconds. It will be less than 300g / cm ² . On the other hand, looking at the sterilization time from the viewpoint of satisfying the microbial composition standard, 3
In seconds, sterilization is insufficient for both general viable bacteria and coliforms. At this time, the heat-resistant spores are in the range of 3000 / g,
This is because the number of bacteria in the unsterilized state is small, and the bactericidal effect is not good. At 5 seconds, the numerical value of the microbial composition standard is satisfied. If it is 10 seconds or more, a good bactericidal effect is obtained against all of general live bacteria, coliform bacteria, and thermospores.

Therefore, the range of sterilization time is 5 to 20 seconds, preferably 10
~ 15 seconds.

(Experimental Example 4) An experimental example for investigating the relationship between the particle size of dried plasma and dried serum and the gel strength and the number of microorganisms after sterilization is shown below. The experimental sample and the sterilizer are the same as those in Experimental Example 1.

"Operating conditions of the sterilizer" ・ Sample filling amount ・ ・ ・ ・ ・ ・ ・ ・ 1kg ・ Superheated steam temperature ・ ・ ・ ・ ・ 150 ℃ ・ Superheated steam pressure ・ ・ ・ ・ 0.3 kg / cm ² · G · Main body heating saturated vapor pressure ··· 1.0 kg / cm ² · G (heating jacket) (about 120 ° C) · Sterilization time by complete contact with superheated steam ···
10 seconds ・ 1 cycle time ・ ・ ・ Approx. 2 minutes ・ Sample cooling temperature after sterilization ・ ・ ・ 40 to 50 ℃ ・ Initial water content ・ ・ ・ 7% by weight ・ Sample particle size ・ ・ ・ 20〜 32 (20 mesh under 32 mesh on, the same applies below), 32-42, 42-48, 48-60, 60
-80, 80-100, 100- (100 mesh under) [Tyler
Scale] The experimental results are shown in the following Table 7 (dry plasma) and Table 8 (dry serum).

As is clear from Tables 7 and 8, the smaller the particle size, the better the bactericidal effect, but the gel strength tends to decrease.

The particle size at the time of sterilization can be 20 mesh under under the microbial component standard, but it should be under 60 mesh under the negative condition according to the custom of food microbial inspection. Since heat-resistant spores are particularly difficult to sterilize, it is considered preferable to limit to 60 mesh under. Therefore, blood powder larger than 60 mesh is preferably crushed to make 60 mesh under when it is commercialized. If crushed after sterilization, there is a risk of sterilization contamination during crushing, so it is safer to sterilize and then package immediately after crushing.
For this reason as well, it is preferable to make 60 mesh under and then sterilize.

(Experimental Example 5) As described above, in the present invention, since the sample directly contacts the high-temperature superheated steam, the sample reaches a temperature as high as that of the superheated steam. Therefore, if it is left as it is, it takes a considerable time to cool it, and it is maintained at a high temperature during that time, which causes a decrease in gel strength. Therefore, after sterilization, the protein should be immediately denatured or cooled to a temperature within the range permitted by the structure of the apparatus.

In order to know these quantitatively, an experiment was conducted to examine the relationship between cooling after sterilization and gel strength. The results are shown below. The sample and sterilizer were the same as in Experimental Example 1.

"Operating conditions of sterilizer" ・ Sample filling amount ・ ・ ・ ・ ・ ・ ・ ・ 1kg ・ Sample particle size ・ ・ ・ 60 mesh under ・ Superheated steam temperature ・ ・ ・ ・ ・ ・ 150 ℃ ・ Superheated steam Pressure ・ ・ ・ ・ ・ ・ 0.3kg / cm ²・ G ・ Main body heating saturated vapor pressure ・ ・ ・ 1.0kg / cm ²・ G (heating jacket) (about 120 ° C) ・ By full contact with superheated steam Sterilization time ...
10 seconds ・ 1 cycle time ・ ・ ・ ・ ・ Approx. 2 minutes ・ Initial moisture ・ ・ ・ 7% by weight ・ Sample cooling temperature after sterilization ・ ・ ・ 15, 40, 60, 80, 100, 1
10, 120, 130, 140, 150 (℃) In addition, the cooling method is to take out the sample from the outlet without using the cooler 25 and put it in a stainless steel container with good heat transfer,
This container is immersed in cooling water, the sample in the container is cooled while stirring, the sample is taken out when it reaches a predetermined cooling temperature, transferred to a 2 l glass beaker, and then left to cool in the atmosphere. I took it.

The experimental results are shown in Table 9 below.

As is clear from Table 9, the decrease in gel strength can be suppressed by performing sufficient cooling immediately after sterilization.

If the cooling temperature exceeds 110 ° C., the rate of gel strength reduction increases. Therefore, the cooling temperature must be 110 ° C or lower.

In this experiment, the amount per lot was set to 1 kg, but in actual production a large amount of bulk is accumulated, so heat dissipation is poor and the rate of temperature drop during natural cooling is low. Therefore, the gel strength is further lowered. It is considered that the cause of the decrease in gel strength in this case is that the internal temperature rises when it is left to cool in the bulk state, and it is left for a long time in a high temperature and high humidity state.

From the above knowledge, it is preferable that the sample after sterilization is cooled immediately to near room temperature, and it should be cooled to 110 ° C. or lower even when sufficient cooling cannot be achieved due to the structure of the device.

In this experiment, the number of microorganisms was not measured because stirring and cooling were performed in an open state.
From the results of ~ 4, there is no problem since the bactericidal effect is sure to be sufficient even when immediately cooled.

"Effects of the Invention" As described above, in the method for producing blood meal having gel strength according to the present invention, the initial water content obtained from blood is 3 to
120-180 ° C for dry blood components with gel strength of 12% by weight
Superheated Steam of is contacted, and after the complete contact state of this superheated steam and the dried blood component is connected for 5 to 20 seconds, the superheated steam and the dried blood component are separated, and immediately after the separation, the dried blood The method is characterized by cooling the components to 110 ° C. or lower.

Therefore, according to the present invention, dried blood components having gel strength, such as dried plasma and dried serum obtained by low temperature drying,
Not only does it impair the water solubility and heat coagulability, but it is possible to sterilize the gel sufficiently without reducing its gel strength.

[Brief description of drawings]

1 and 2 are block diagrams of a direct heat sterilizer suitable for use in the blood meal sterilizing method according to the present invention, and FIGS. 3 (a) and 3 (b) are main parts of the direct heat sterilizer. The block diagram which shows a modification, FIG. 4 is a block diagram of the drop sterilizer applicable to the direct heat sterilizer used for the method of this invention,
FIG. 5 is a block diagram of a fluidized bed type sterilizer applicable to the direct heating sterilizer used in the method of the present invention, and FIG. 6 is a process diagram for producing blood powder. 9: Direct heating sterilizer, 9a: Sterilizer body, 9c: Hollow shaft, 9d: Motor, 10: Fixed amount feeder, 11:
Superheated steam supply pipe, 13 …… Super heater, 19 …… Discharge valve, 20 …… Air carrier pipe, 23 …… Cyclone, 25 ……
Cooler, 40 ... Sterilization tube, 41 ... Steam generator, 42 ... Super heater, 44 ... Separator, 46 ... Transport tube, 48 ... Blower, 50 ... Separator, 53 ... Cooling tube , 54 …… Blower, 56 …… Separator.

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Haruhiko Nagasawa 1-9-3 Kamatahonmachi, Ota-ku, Tokyo Inside Niigata Iron Works Co., Ltd. (72) Inventor Miko Nishimura 1-3-9 Kamatahonmachi, Ota-ku, Tokyo Niigata Iron Works Co., Ltd.

Claims (4)

[Claims] 1. Initial water content obtained from blood is 3 to 12% by weight.
After contacting the superheated steam at 120 to 180 ° C. with the dry blood component having the gel strength of, and maintaining the complete contact state between the superheated steam and the dry blood component for 5 to 20 seconds, the superheated steam and the dry blood component are separated. Separate, and immediately after separation, dry blood components at 110 ℃
A method for producing a sterilized blood meal having gel strength, which comprises cooling as follows. 2. The method for producing blood powder according to claim 1, wherein the dried blood component is dried by keeping its product temperature at 50 ° C. or lower. 3. The method for producing blood powder according to claim 1, wherein the dried blood component is crushed to 60 mesh or less. 4. The method for producing blood powder according to claim 1, wherein the dried blood component is dried plasma and / or dried serum.