JPH0829068B2 - Blood powder sterilization method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION “Industrial field of application” The present invention relates to indirect heating from non-denatured dried blood components such as dried plasma, dried serum, dried blood cells or dried whole blood obtained from animal blood by low temperature drying. The present invention relates to a method for sterilizing blood meal, which can obtain heat-sterilized blood meal without impairing various properties such as water solubility and gel strength as a processed material for foods or foods, pharmaceuticals, etc. .

"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, blood that makes use of the excellent nutritional value of blood components and the various physical properties of blood components in processing such as food As a treatment method, the blood is centrifuged to separate the blood into blood cells and plasma, or fibrin is removed from the blood, the blood is centrifuged to separate into blood cells and serum, and each separated is spray dried, There is provided a method for obtaining blood meal as 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, 30g / cm ² or more for pig plasma and 500g / 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, there was a problem with food safety. When blood meal is used as food or processed material such as food, 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. This sterilization method is an excellent sanitary sterilization method, but it causes heat denaturation of proteins, reduces various properties such as gel strength, and causes a marked decrease in the 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. Blood cells are reddish brown and have a nutritionally excellent composition similar to that of plasma and serum. Looking at, about 90% (dry matter conversion) and 70-75% of plasma and serum
Although it is superior to, it does not originally have gel strength. In addition, even if the solubility and thermocoagulability can be maintained when obtaining a dry product of plasma or serum, it is impossible to measure the gel strength because the product obtained by heat-coagulating the dry product is shabby and soft. In many cases, even if the solubility can be maintained at about 80% when obtaining a dried product, the gel strength will be greatly reduced.

Therefore, not only whole blood and blood cell components, but also blood components of all types including plasma components and serum components are dried products. It must be a method that not only impairs the heat coagulation property but also maintains the gel strength.

The present inventors, as a result of various studies in view of the above circumstances,
Blood plasma such as plasma and serum obtained by the above low-temperature drying is heated by limiting the water temperature to 12% or less using an indirect heater and limiting the product temperature to 110 ° C or less. If so, it was found that the gel strength hardly decreased.

The present invention was made on the basis of the above findings, and its purpose is to utilize an indirect heater to produce not only water solubility and thermocoagulability, but also almost no decrease in gel strength. It is an object of the present invention to provide a method for sterilizing blood powder capable of sterilizing general live bacteria, Escherichia coli, etc. (commercial sterilization).

"Means for Solving Problems" The present invention has an indirect heating that has a paddle-type or screw-type stirring blade inside a container and heats an introduced material inside the container by passing a heating medium through a jacket or the like of the container. It is a method of sterilizing blood powder using a machine, where the initial water content is 3 to
At 20% by weight, a non-denatured dry blood component of 20 mesh or less was filled into the container of the indirect heater so that the filling rate for the internal stirring blade was 50 to 100%, and the ventilation in the container was continuously performed. Alternatively, the method is characterized by obtaining the sterilized blood meal by heating the above-mentioned undenatured dry blood component to 90 to 110 ° C while carrying out intermittently.

[Operation] According to the above method, not only dried whole blood and dried blood cells obtained by low-temperature drying, but also all types of unmodified dried blood components including dried plasma and dried serum are treated with their water solubility and heat. Not only is the coagulability not impaired, but the gel strength is not substantially reduced, and it is possible to sterilize sufficiently.

In the sterilization of such blood powder, among blood powder, sterilization of dry plasma and dry serum does not reduce the gel strength thereof, if the conditions are such that dry blood cells, water solubility of blood powder necessary in the sterilization of dry whole blood, Maintenance of heat coagulation property is automatically ensured according to the processing conditions, and therefore, in the following examples,
The dry plasma will be mainly described as the undenatured dry blood component for description.

[Example] As shown in FIG. 2, blood is collected from the livestock animal 1 hygienically 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. Mix about 0.5% by weight as sodium citrate to prevent blood coagulation. The collected blood is strainer 3
After removing contaminants such as meat pieces, fat pieces, and hair that have been mixed in through, they are once stored in the inspection tank 4. Inspection tank 4
After checking the presence or absence of slaughter of the disease by inspecting the carcass etc. while storing in the blood, only blood confirmed to be hygienic is passed through the next heat exchanger 5, cooled, and then centrifuged. Send to separator 6. Separation is performed by this high-speed continuous centrifuge 6, and the light liquid portion is collected as plasma liquid and the heavy liquid portion is collected as blood cell liquid. The obtained plasma liquid is sent to the next plasma vacuum low-temperature dryer 7, where the product temperature is preferably 40 ° C. or lower when the plasma liquid concentration is low, and the product temperature is high even when the concentration is as high as 50% or more. To 50 ° C
Keep the temperature below and perform drying at a low temperature so that the proteins in the plasma fluid will not be heat-denatured. 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 fluid separated by the centrifuge is stored in a storage tank for a while, the fibrin is coagulated and precipitated, and the coagulated fibrin is removed by sieving, filtering, or using a strainer to obtain a serum solution, and the serum is obtained. The liquid may be dried in a vacuum low temperature dryer as described above.

In order to effectively carry out the present invention, weight is a common sense regarding the handling of foods containing protein in the blood collecting step, the separating step and the drying step before the sterilization step which is the next step. 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 dry plasma and dry serum produced as described above correspond to the non-denatured dry blood component of the present invention (hereinafter, simply referred to as dry blood component) including dry whole blood, and both have a solubility of 90% or more. Yes, the plasma powder gel strength is
500g / cm ² or more for cattle and 300g / cm ² or more for pigs,
Although it varies slightly depending on the type of slaughtered meat, it has a high value and is an excellent intermediate product in terms of physical properties. However, in terms of the number of microorganisms, it is often the case that a large amount of microorganisms is contained in the order of 10 ⁵ to 10 ⁷ per 1 g of blood meal.

Subsequently, the dried plasma and dried serum are put into an indirect heating sterilizer (indirect heating device) 9. Heat sterilization here means commercial sterilization (Commercial Sterilizatio), which is used as a food material to sterilize microorganisms to the extent that it does not interfere.
n) is included. That is, it includes a method of reducing the number of coliform bacteria, which is an index of harmful bacteria, without significantly deteriorating the physical properties of blood powder, and is preferably a method in which the exact quantity per 100 g is 30 or less.

The above-mentioned gel strength is an important change in physical properties that occurs during the heat sterilization of dried plasma and dried serum. Gel strength is an important physical property for increasing the value of plasma and serum in food and food processing.

 The outline of the method for measuring the gel strength is shown below.

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., a vinylidene chloride tube is peeled off, and a breaking point of a cylindrical sample cut into a length of 30 mm is measured using a rheometer. In the examples described below, 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 main items of the technical composition of this sterilization process are appropriate product temperature during heat sterilization, maintenance of time, adjustment of initial water content of dried blood component which is the sterilizer, and related indirect heat sterilizer to be used. Therefore, there are appropriate controls such as temperature adjustment of the heating medium for heating the sterilizer, ventilation in the sterilization chamber (container), and stirring. Hereinafter, each of these items will be described in detail.

(I) Product temperature during sterilization The product temperature during sterilization is approximately 90 to 110 ° C,
Preferably, it is suitable to maintain at about 95 to 105 ° C.
90 if the number of microorganisms contained in the dried blood component is low, or if the microorganisms contained are easily sterilized.
In some cases, the temperature may reach the target at a temperature of around ℃, but if the number of microorganisms is large or there are many microorganisms that are difficult to sterilize, the product temperature must be around 110 ° C. The higher the product temperature is, the better the bactericidal effect is, but the gel strength is apt to be lowered, so that the temperature is preferably 95 ° C to 105 ° C.

The product temperature maintenance time differs depending on whether it is a batch system or a continuous system. For example, in the batch type of indirect heating, the product temperature rises with time until the temperature rises, and the sterilizing effect is exerted during that time as well. Therefore, in some cases, the temperature may be lowered immediately when the predetermined product temperature is reached. As described above, it is difficult to regulate the sterilization time so accurately. However, in the case of the batch type of indirect heating, it is good to carry out for about 10 minutes after raising the temperature to about sterilization temperature, and in the case of the continuous type of indirect heating, the residence time in the sterilizer container is about 20 to 60 minutes. You can do it in.

(Ii) Initial water content of dried blood components The initial water content of dried blood components is very important. When heat sterilization is started with a low initial water content of less than 3% by weight, the bactericidal effect is inferior, and when the initial water content exceeds 12% by weight, the bactericidal effect is good, but the gel strength decreases and the quality deteriorates. To do. Therefore, the range of the 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 5 to 6% by weight.

When the initial water content is less than 3% by weight, in order to effectively sterilize, spray moistening is performed, and the mixture is further well mixed by stirring to uniformly moisturize it, and after heating it to a predetermined water content, heat it. It is preferable to carry out sterilization. In addition, in this specification, the water content is a value represented by the following equation.

(Iii) Crushing of dried blood component As a method for drying plasma liquid or serum liquid which is a blood component having gel strength, a spray dryer or a stirring type vacuum dryer is used. (Dry blood component) has irregular particle size, and
From the viewpoint of the bactericidal effect, it is better to pulverize the dried blood component to 20 mesh under, preferably 60 mesh under before sterilizing. 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. .

(Iv) Ventilation in the sterilization chamber In the indirect heating type sterilizer, when the sterilization is hermetically closed and heat sterilized, the water contained in the dried blood component evaporates, and the sterilization becomes partially moist heat sterilization and saturated. There is a possibility that the gel strength of the dried blood component may be reduced by the high temperature steam close to the state. Therefore, it is necessary to send an appropriate amount of inert gas such as nitrogen or air into the sterilization chamber and expel the generated water vapor as appropriate to ventilate the sterilization chamber and prevent the gel strength from decreasing. The amount of gas to be ventilated differs depending on the scale of the device and the agitation speed of the dried blood components. Generally, in small-scale devices, the heat transfer area per dried blood component is large, so the heat transfer is fast and the required gas The amount of ventilation of is also large.

On the contrary, when the scale is increased, the heat transfer area per dried blood component is small and the heat transfer is slowed down, so that the required air flow rate is small. As an example, when sterilizing about 100-200 g of dried blood components, the required aeration amount is about 0.1-0.2 Nl per minute of dried blood components, but on a scale of 30-40 Kg. Ventilation around 0.02Nl is enough. The required aeration amount is also affected by the speed of stirring. Therefore,
It is necessary to confirm the required air flow rate by experiment for each device and scale used, but it is necessary to confirm that
Aeration rates of 0.02 to 0.2 Nl are preferred.

(V) Temperature of heating medium In the case of indirectly heating a heating medium such as steam or mineral oil into the jacket or coil of the sterilization chamber or the inside of the blade of the stirrer to raise the temperature of the dried blood components, the temperature of the heating medium is sterilized. The temperature is higher than the temperature, the greater the temperature difference between the product temperature and the heating medium, the easier it is to raise the temperature, but if it is too high, the temperature of the heat transfer surface becomes too high and the dry blood component is heated at the contact surface. The temperature of the heat transfer medium must be carefully considered because it may cause a decrease in gel strength.

(Vi) Ventilation Inflow gas heating temperature Although the temperature of the inflow gas for ventilating the indirect heating type sterilization chamber may be room temperature, it is better to send the preheated gas to increase the product temperature. There is an advantage that the heat transfer surface is small and there is no need to raise the temperature of the heating medium too much. However, if the temperature is too high above the sterilization temperature,
Since it comes into direct contact with the dried blood component that is the substance to be sterilized, the gel strength is reduced, which is not preferable. The preheating temperature of the ventilation inflow gas is preferably 110 ° C. or lower. Also, the cheapest air may be used as the ventilation gas for ventilation. For the purpose of commercial sterilization, the inflowing air does not need to use sterilized sterile air.

(Vii) Stirring If sterilization is performed without stirring the dried blood components at all, steam will be trapped in the dried blood components, which will cause a decrease in gel strength.

Generally, as a method of stirring, there are a method of rotating the entire sterilization container and a method of inserting a stirring blade of a screw type, a paddle type or the like in the sterilization container and stirring by this. Further, even with the method using a stirring blade, a so-called paddle blade type in which the stirring blade is immersed in the object to be sterilized (object to be heated) by 50% or more and a scraping blade immersed in about 30% are provided, and the sample is scattered by this blade. The blade type is known.

In the conventional method of rotating the entire container of the sterilizer or in the scraping blade method, the dipping rate of the blade (hereinafter referred to as the filling rate) is reduced and the object to be spread is spread over the entire surface of the container. Since the particle size of blood powder, which is a substance to be sterilized, is usually small and the apparent specific gravity of the blood powder is light, dried blood components are scattered to the exhaust side by ventilation. Therefore, measures to prevent scattering are necessary. Further, the method of rotating the entire container is good in the effect of stirring, but the dried blood component is scattered in the container, and the dried blood component is further scattered during ventilation. Therefore, when this method is adopted, it is necessary to install sufficient dust collecting equipment to collect the dried blood component.

In order to solve these, in the present invention, the sterilization container is fixed, an indirect heating type sterilizer having a paddle type or screw type stirring blade is used inside the container, and the blade is filled with dry blood components. The heat sterilization is performed by increasing the rate to 50 to 100%, preferably 80 to 100%.

According to the above technical elements, it is possible to achieve the purpose of commercial sterilization by heat sterilizing dried blood components, and to suppress the decrease in gel strength as much as possible,
It becomes possible to produce high-value-added blood meal such as excellent foods or raw materials for food processing.

Blood meal sterilized in this way can be packed in a bagging machine if necessary.
Packed in 10. Incidentally, in FIG. 2, reference numerals 11, 12, 13,
Reference numeral 14 indicates a vacuum low-temperature dryer, a crusher, an indirect heating sterilizer (indirect heating machine), and a bagging machine, respectively, for blood cell fluid, which are dried under the same conditions as those described for the plasma fluid. Production of blood cells and heat sterilization thereof are performed.

Next, an example of an experiment conducted to confirm the effect of the above-mentioned embodiment will be described.

The apparatus used for this experiment is a modification of a known rotary evaporator (RE-45 type, manufactured by Yamato Scientific Co., Ltd.). The schematic configuration of this experimental apparatus is shown in FIG. In the figure, reference numeral 20 is a compressed air storage tank for storing compressed air from a compressor not shown, 21 is a pressure gauge, 22 is an air inlet thermometer, 23 is an air flow meter, 24 is a connecting rubber tube for air feeding, and 25 is heating. Oil bath, 26 heating medium, 27 sample, 28 eggplant-shaped flask, 29 bar thermometer, 30 air inlet pipe, 31 air exhaust pipe, 32 eggplant-shaped flask 28 rotary joint 36
The bearing main part that is supported while rotating through 33, 33 is a cooling pipe,
Reference numeral 34 is a rubber stopper, and 35 is an exhaust connecting rubber tube. This rotary evaporator is used for vacuuming a sample in an eggplant-shaped flask 28 under vacuum.
27 is usually used for concentrating or drying under vacuum, but in this experiment, the switching cock on the rubber stopper 34 was removed, the rubber stopper 34 was attached, and the rubber stopper 34 was attached. A rod-shaped thermometer 29, an air inlet pipe 30, and an air exhaust pipe 31 are attached to the. A bar thermometer 29
The temperature sensation part was inserted into the sample 27 of the eggplant-shaped flask 28, and the tip of the air inlet tube 30 was enlarged so that the air was widely distributed on the surface of the sample 27. Further, the air exhaust pipe 31 also reaches the inside of the eggplant-shaped flask 28 in the same manner, and the tip end portion thereof has a widened structure so that the air containing moisture generated from the sample 27 can be easily collected. The tip positions of the air inlet pipe 30 and the air exhaust pipe 31 inside the eggplant-shaped flask 28 are closer to the surface of the sample 27 in the air inlet pipe 30, and the tip end of the air exhaust pipe 11 is the sample. The distance from the surface of 27 is adjusted so as to prevent the sample scattered by the incoming air from flowing out from the air exhaust pipe 31.

 The outline of the operation method of this device will be described below.

First, an appropriate amount of sample (dry blood component) 27 is collected in an eggplant-shaped flask 28. The temperature of the heating oil bath is raised to a constant temperature in advance. Compressed air is sent to the compressed air storage tank 20 to measure pressure and temperature. Attach the eggplant-shaped flask 28 to the rotary joint 36 and rotate it in an oil bath. Air flow meter 23
, A predetermined air is sent through the air inlet pipe 30, and the exhaust air is exhausted through the air exhaust pipe 31. The temperature of the sample 27 is measured by a rod-shaped thermometer 29 inserted in the sample 27.
The amount of air sent in was corrected to the standard state (1 atmospheric pressure, 0 ° C.) by the measured temperature and pressure and displayed. The gel strength was measured by the method described above.

(Experimental Example 1) In order to confirm the influence of the product temperature and the gel strength of the dried blood component when heat sterilized, bovine blood (0.5% by weight of sodium citrate as an anticoagulant was added to blood during blood collection) ) At 4000 rpm for 20 minutes in a centrifuge tube centrifuge,
The separated plasma liquid is vacuum dried while keeping the product temperature at 40 ° C or lower,
The dried plasma thus obtained was tested in the above experimental apparatus (Fig. 3).

 The experimental conditions are shown below.

・ Flask used ・ ・ ・ 1 volume pleated eggplant flask ・ Sample type ・ ・ ・ Bovine dried plasma (water content 7%, gel strength)
584g / cm ² , particle size 60 mesh under) ・ Sample filling amount ・ ・ ・ 120g ・ Sterilization temperature ・ ・ ・ 80, 90, 95, 100, 105, 110, 120 ℃
(Product temperature) ・ Sterilization time ・ ・ ・ 10 minutes ・ Ventilation air (unsterilized) amount and temperature ・ ・ ・ 0.15Nl / g ・ mi
n, 20 ° C ・ Number of rotations ・ ・ ・ 6r.pm ・ Analysis items ・ ・ ・ Water, gel strength, general viable cell count, coliforms Experimental results are shown in Table 1 below. From the results in this table, it is understood that the product temperature in the range of 90 to 110 ° C. is appropriate in the case of bovine dried plasma. In addition, as a result of performing a similar test on the dried bovine serum obtained by similarly removing the fibrin from the bovine blood and centrifuging the same, the result was almost the same as the case of plasma. Moreover, almost the same results were obtained for dried pork plasma powder and dried pork serum powder.

(Experimental Example 2) In order to sterilize by heating without lowering the gel strength, the initial water content of the dried blood component before heat sterilization is important.

The results of an experiment in which the effect of initial water content on heat sterilization was investigated using pig plasma powder and serum powder are shown below. The experimental apparatus shown in FIG. 3 was used for the experiment. First, pig blood (when collecting blood, sodium citrate as an anticoagulant was added to blood.
5 wt% added) was centrifuged at 4000 rpm for 20 minutes, the separated plasma liquid was vacuum dried at a product temperature of 50 ° C. or lower, and an experiment was performed using the obtained pig dried plasma. The experimental conditions are shown below.・ Flask used ・ ・ ・ Eggplant flask with 1 volume fold ・ Sample type ・ ・ ・ Pig dried plasma [initial water content 14, 12, 10,
8, 6, 4, 3, 2% by weight, particle size 60 mesh under] -Sample filling amount ... 120g-Sterilization temperature ... 100 ° C (article temperature) -Sterilization time ... 10 minutes-Ventilation air (None Sterilization) Amount and temperature: 0.15 Nl / g ・ mi
n, 20 ° C ・ Number of rotations ・ ・ ・ 6r.pm ・ Analysis items ・ ・ ・ Gel strength, general viable cell count, coliforms In addition, dried pork plasma has a water content of 7.5% by weight and a gel strength of 351g /
Since it was cm ² , the dried plasma with 8-14 wt% water used in the experiment humidified sterile water, and for the water sample of 6 wt% or less, use a vacuum dryer in which the sample container was sterilized in advance. It was dried and adjusted.

 The experimental results are shown in Table 2 below.

Displayed in.

As shown in the above table, when the initial water content is 2% by weight or less, the quality is good, but the bactericidal effect of the general viable cell count is poor. When the water content is 12% by weight or more, the bactericidal effect is good, but the gel strength decreases. The initial water content is 3 to 12% by weight, although there are some differences depending on the sterilization conditions such as sterilization temperature, ventilation volume, and rotation speed.
The range of should be kept.

Fibrin was removed from the pig blood to which the anticoagulant had been added, centrifugation was performed, and the same experiment was performed using the dried pig serum obtained by vacuum drying. The results are shown in Table 3 below. The experimental conditions are the same as for pig dry plasma.

As shown in the table above, the tendency of dried pig serum was almost the same as that of dried pig plasma. The same experiment was performed with the bovine dried plasma and serum of Example 1, but similar results were obtained.

If the initial water content is too low as a tendency in heat sterilization, the effect on quality deterioration is small, but the desired sterilization effect is poor. Further, if the initial water content is too high, the bactericidal effect is good, but the gel strength is greatly reduced, and the commercial value is reduced. The initial water content is 3 to 12% by weight, preferably 4 to 10% by weight, more preferably 5 to 6% by weight.

(Experimental Example 3) Effect of bactericidal effect due to difference in particle size of dry plasma Pigment dried plasma having a water content of 6.7% by weight and gel strength of 374 g / cm ² obtained by the same method as in Experimental Example 2 was divided by a filter for particle size. An experiment was conducted for each particle size using the above-mentioned experimental apparatus (Fig. 2).

 The experimental conditions are shown below.

・ Flask used ・ ・ ・ 1 volume pleated eggplant flask ・ Sample type ・ ・ ・ Dry pig plasma (water 6.7% by weight, gel strength 374 g / cm ² ) ・ Particle size ・ ・ ・ 4 mesh under 20 mesh on, 20 mesh under 60 Mesh on, 60 mesh under ・ Sample filling amount ・ ・ ・ 120g ・ Sterilization temperature ・ ・ ・ 105 ℃ ・ Sterilization time ・ ・ ・ 10 minutes ・ Ventilation air (unsterilized) amount and temperature ・ ・ ・ 0.15Nl / g ・ mi
n, 20 ° C ・ Number of rotations ・ ・ ・ 6r.pm ・ Analysis item ・ ・ ・ Gel strength, general viable cell count The experimental results are shown in Table 4 below.

As shown in the above table, the finer the crushed particles, the better the bactericidal effect. It is better to sterilize after making the particle size 20 mesh or less, preferably 60 mesh or less.

(Experimental Example 4) In the indirect heating type heat sterilization, the sterilizing effect and the gel strength of dry plasma were compared between the case where the sterilization chamber was ventilated and the case where no ventilation was performed at all. A bovine dry plasma having a water content of 7.0% by weight and a gel strength of 579 g / cm ² obtained by the same method as in Experimental Example 1 was used by using the above experimental apparatus (FIG. 2).

 The experimental conditions are shown below.

・ Flask used: Eggplant flask with 100 ml folds ・ Sample type: Dry cow plasma (water content: 7.0% by weight, particle size: 60)
Mesh under) ・ Sample filling amount ・ ・ ・ 15g ・ Sterilization temperature ・ ・ ・ 105 ℃ (Product temperature) ・ Sterilization time ・ ・ ・ 10 minutes ・ [Ventilation air (unsterilized) amount and temperature] ・ ・ ・ 0.15Nl / g
・ Min, 20 ℃ ・ Rotation rate ・ ・ ・ 6r.pm ・ Analysis item ・ ・ ・ Gel strength, general viable cell count The following table 5 shows the experimental results.

As is clear from the experimental results in the above table, the bactericidal effect of general viable bacteria and Escherichia coli was good in both indirect heating type heat sterilization with and without ventilation. Thermospore-forming spores were negative in the sample before sterilization. However, with respect to the gel strength, there is little decrease in the case of ventilation, and the product quality target value can be almost maintained, but in the case of no ventilation, the gel strength is remarkably deteriorated.

An experiment was carried out on the dried serum in the same condition, and the similar result was obtained. By ventilating both dry plasma and serum, it was possible to suppress the decrease in gel strength due to heat sterilization and maintain the target value of product quality. Regarding thermostable bacteria, it is generally said that the effect of heat sterilization is small, but by using fresh blood and performing hygienic pretreatment, values below the target value can be obtained at the stage of dried blood powder. It was confirmed that this experiment also showed a negative value of 300 / g or less at the stage of dry plasma before sterilization.

(Experimental Example 5) Regarding the influence of the temperature of the gas for ventilating the sterilization chamber necessary for the indirect heat sterilization, the water content was 6.7% by weight, the gel strength was 385 g / cm ² , and 60 mesh under was obtained by the same method as in Experimental Example 2. An experiment was conducted using the above-mentioned experimental apparatus (FIG. 5) using pig dry plasma. As a result, by using heated air at 80 to 120 ° C, it took 10 to 20 minutes to reach the target product temperature, but was shortened to 5 minutes or less.

However, if the temperature of the heated air is too high, the quality is affected. Therefore, it is preferable to set the temperature to 110 ° C. or lower, like the product temperature. The experimental results of the influence of the heating air temperature on the gel strength are shown in Table 6 below.

During the heat sterilization, the temperature of the dried plasma was raised to 100 ° C., kept at that temperature for 10 minutes, and then lowered.

Therefore, the air blown to the sterilization chamber in the indirect heating type heat sterilization may be at room temperature, but sending preheated air requires less time to raise the temperature and lowers the temperature of the heating medium.

 The conditions of the above experiment are shown below.

・ Flask used ・ ・ ・ 1 volume pleated eggplant flask ・ Sample type ・ ・ ・ Pig dried plasma (water 6.7% by weight, particle size 60)
・ Mesh under) ・ Sample filling amount ・ ・ ・ 150g ・ Sterilization temperature ・ ・ ・ 100 ℃ (Product temperature) ・ Sterilization time ・ ・ ・ 10 minutes ・ Ventilation air amount ・ ・ ・ 0.15Nl / g ・ min ・ Ventilation air temperature ・ ・・ 80, 90, 100, 110, 120 ℃ ・ Rotation rate ・ ・ ・ 6r.pm (Experimental example 6) In order to investigate the influence of stirring in heat sterilization, the water content was 6.7% by weight and the gel strength was 385 g /
Experiments were carried out with the above-mentioned experimental apparatus (Fig. 3) using cm ² of pig dry plasma.

 The experimental conditions are shown below.

・ Sterilization temperature ・ ・ ・ 100 ℃ (Product temperature) ・ Flask used ・ ・ ・ 1 volume pleated eggplant flask ・ Sample type ・ ・ ・ Pig dried plasma (water 6.7% by weight, particle size 60)
・ Mesh under) ・ Sample filling amount ・ ・ ・ 120g ・ Ventilation air (unsterilized) amount and temperature ・ ・ ・ 0.16Nl / g ・ mi
n, 20 ° C.-Number of revolutions ... 0, 1, 2, 5, 10, 20 rpm. Oil bath temperature ... 120-125 ° C. The experimental results are shown in Table 7.

As shown in the table above, the gel strength deteriorates at the number of revolutions of 0, but the deterioration of the product temperature can be prevented even if the sample is moving even at one revolution per minute. Note that when the stirring is small, overheating may occur in the boundary film portion, so it is better to control the heating medium temperature to be somewhat lower.

As a method of stirring the dried blood component, there are a method of rotating the container itself containing the sterilized sample as shown in the experimental apparatus (FIG. 3) and a method of placing the stirrer in the sterilization chamber. The method of placing the stirrer in the sterilization chamber is more advantageous in terms of scattering of the sample during ventilation.

(Experimental Example 7) As described above, ventilation is the most important requirement for performing indirect heating sterilization.

The required ventilation volume varies considerably depending on the size of the device and the number of revolutions of stirring.

Below, the experimental results in a small experimental device and an example in an actual device are shown.

1) Example in experimental apparatus Bovine dried plasma having a water content of 6.8% by weight and a gel strength of 565 g / cm ² obtained in the same manner as in Example 1 was sterilized using the above experimental apparatus (Fig. 3). The experimental conditions are shown below.

・ Sterilization temperature ・ ・ ・ 105 ℃ (Product temperature) ・ Flask used ・ ・ ・ 100ml volume eggplant flask with folds ・ Sample type ・ ・ ・ Bovine dried plasma (water content 6.8% by weight, particle size 60)
Mesh under) ・ Sample filling amount ・ ・ ・ 15g ・ Ventilation air ventilation rate ・ ・ ・ (1) 0.5Nl / min, (2) 1.0Nl
/ min, (3) 1.5Nl / min, (4) 2.5Nl / min, ・ Ventilation air temperature ・ ・ ・ 105 ℃ ・ Sterilization time ・ ・ ・ 10 minutes ・ Rotational speed ・ ・ ・ 6r.pm ・ Oil bath temperature ・・ ・ 125 ℃ ・ Analytical items: Moisture and gel strength Table 8 shows the experimental results. As shown in this table, the gel strength can be maintained at 500 g / cm ² or more when the air flow rate per unit sample is about 0.15 Nl / g · min or more. For each of the above, the number of viable bacteria and coliform bacteria were measured. Regarding the sterilized products, the general viable cell count was 300 cells / g or less, and the coliform bacteria were negative. Based on the experimental results shown in Table 8, 7.0 wt% of water obtained by the same method, gel strength 591 g / cm ² , 60 mesh under particle size of cattle dried plasma was re-tested at 100 ° C and 105 ° C. The results of measuring the number of bacteria are shown in Table 9.

Although there is a relationship between the ventilation volume and the rotation speed, it is better to slightly increase the ventilation ventilation volume when the rotation speed is lowered, and when the rotation speed is set to 1 rpm, the gel strength is set to 500 g / cm ² . In order to maintain it, a ventilation volume of about 0.2 Nl / g · min was required per unit sample.

2) Example of actual device In the experiment, a paddle type continuous indirect heating machine as shown in FIGS. 1 (a) and (b) was used.

Although this paddle type indirect heater is originally used as a simple dryer, it can be used as a sterilizer for dried blood components as described below.

As shown in the figure, this paddle type continuous indirect heater is
A large number of stirring paddles (stirring blades) 41 are rotatably provided by a hollow rotating shaft 42 inside a sterilization container 40 that is installed so as to be inclined with respect to the horizontal plane.
41 is also hollow, and has a structure in which a heat medium (heating oil) 43 flowing in the hollow rotating shaft 42 circulates. A ventilation air outlet and blood powder inlet 44 is formed on the upper surface of the inclined sterilization container 40, and on the lower surface of the upper surface,
A ventilation air inlet 45 is formed. Further, a blood powder discharge port 46 is formed on the lower surface of the container 40 on the lower side, and the discharge port 46 is opened and closed by a rotary valve 46a. Further, the heat medium 43 is also configured to flow through the outer peripheral surface of the container 40. Therefore, the dried blood component introduced into the container 40 is indirectly sterilized by heating through the paddles 41 and the wall of the container 40 while being agitated by the many rotating paddles 41. In addition,
Reference numeral 47 in the figure indicates an overflow game. Ventilation is performed by continuously flowing heated air (in some cases, cold air) from the ventilation air inlet 45 in the direction opposite to the flow of the raw material.

In this experiment, the filling rate of the accumulated dried blood component in the container 40 was 100% at the highest position of the paddle 41 and 0% at the lowest position.
In other words, in other words, the height of the overflow gate 47 on the discharge port 46 side was adjusted so that the ratio of the height of the accumulated dry blood component to the diameter of the entire paddle 41 was 87%. . In this case, the volume occupied by the dry blood component in the container 40 is about 60 l, and about 36 for blood cell powder (specific gravity 0.6).
About 39 kg of Kg and plasma powder (specific gravity 0.65) will enter the container 40.

The experiment of the required amount of aeration using the above-mentioned apparatus was conducted in Example 2.
Water content 6.8% by weight, gel strength 362g / cm ²
Of pig dry plasma.

 The experimental conditions are shown below.

・ Sample type: Pig dried plasma (water content 6.8% by weight, particle size 60
Mesh under) ・ Product temperature ・ ・ ・ 100 ℃ (Product temperature) ・ Heat medium temperature ・ ・ ・ 105 ℃ ・ Paddle rotation speed ・ ・ ・ 38r.pm ・ Fill rate ・ ・ ・ 87% ・ Ventilation air temperature ・ ・ ・ 100 Ventilation ventilation volume: 0.5 to 2.5 Nm ³ / min Ventilation volume per unit sample: 0.0055 to 0.033 Nl / gm
in ・ Sample supply rate ・ ・ ・ 36kg / hr ・ Dwelling (sterilization) time ・ ・ ・ 55 minutes Table 10 shows the test results. As shown in this table, the required air flow rate is 0.025 Nl / g · min per unit sample, and the decrease in product temperature is small. As a result of repeated experiments on the ventilation volume around this, the required ventilation volume was approximately 0.02 Nl / gmin.
It turned out that this is the end. Similar experimental results were obtained for pig serum powder and bovine serum powder.

As described above, it is considered that the difference in the required air flow between the experimental device and the actual device is due to the fact that the experimental device has a small container and a short path of the introduced air occurs. Therefore, in a small-sized device, it is necessary to keep this in mind and take a large amount of ventilation.

(Example 8) The following is an experimental example in which the relationship between the filling rate of the stirring blade of the sterilizer equipped with the paddle type stirrer as shown in Fig. 1 and the scattering of the sample was examined.

Using the sterilizer (indirect heating machine) shown in FIG. 1, experiments were conducted using pig plasma powder.

 The experimental conditions are shown below.

・ Sample type ・ ・ ・ Pig dried plasma (water content 6.1% by weight, gel strength 351g / cm ² , 60 mesh under) ・ Sterilization temperature ・ ・ ・ 100 ℃ (product temperature) ・ Heat medium temperature ・ ・ ・ 105 ℃ ・ Paddle rotation Number ・ ・ ・ 38r.pm ・ Filling rate ・ ・ ・ 100%, 87%, 50% ・ Ventilation air temperature ・ ・ ・ 100 ℃ ・ Ventilation ventilation rate ・ ・ ・ 1.2Nm ³ / min ・ Sample supply rate ・ ・ ・ 36kg / hr ・ Dwelling (sterilization) time ・ ・ ・ 55 minutes The experimental results are shown in Table 11. As shown in this table, the higher the filling rate, the lower the powder scattering rate. If the filling rate is 50%, the scattering rate can be suppressed to about 10%. The gel strength of 100% or less had a gel strength of 300 g / cm ² or more, but the gel strength of 105% or more had a low scattering rate but a gel strength of 200 g / cm ² or less. Was not preferable.

Although the vacuum drying method was used to obtain the dried blood component in the above-mentioned examples, the present invention is not limited to this, and a spray drying method or a freeze drying method may be used. Further, ventilation in the sterilization container of the indirect heater may be performed intermittently, and instead of sending the gas to the sterilization container with a blower, ventilation is performed by sucking the gas in the sterilization container. Good. Also, the paddle type was explained as an indirect heating machine, but a screw type indirect heating machine in which this paddle is a screw may be used, and a multi-axis indirect type in which the axes of the screw and paddle are arranged in parallel and in multiple stages A heating machine can also be used. Further, it goes without saying that a vacuum indirect heating dryer for producing dried blood components may be used as it is as a sterilizer by stopping the operation of the vacuum means.

As described above, the present invention is an indirect heating machine that has a paddle type or screw type stirring blade inside the container and heats the introduced substance inside the container by passing a heat medium through a jacket or the like inside the container. A method for sterilizing blood powder by using the above method, wherein an undenatured dry blood component having an initial water content of 3 to 12% by weight and a mesh of 20 or less is filled in a container of the indirect heater with a filling rate of 50 inside the stirring blade. It is filled to be 100%, and the sterilized blood powder is obtained by heating the undenatured dry blood component to 90 to 110 ° C. while continuously or intermittently performing ventilation in the container. Is the method.

According to the present invention, not only dried whole blood and dried blood cells obtained by low-temperature drying, but also all types of unmodified dried blood components, including dried plasma and dried serum, have their water solubility and thermocoagulability. Not only is it not impaired, but it is possible to sterilize the gel sufficiently without substantially lowering its gel strength.

[Brief description of drawings]

1 (a) and 1 (b) show an actual apparatus used for an experiment of the method of the present invention, (a) is a side sectional configuration diagram, and (b) is (a).
FIG. 2 is a cross-sectional configuration view taken along the line BB in FIG. 2, FIG. 2 is a process drawing of blood powder, and FIG. 3 is a configuration diagram of an experimental apparatus used for an experiment of the method of the present invention. 40 …… container, 41 …… stirring paddle (stirring blade), 43 …… heat medium.

Front page continuation (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 Company Niigata Iron Works

Claims (8)

[Claims] 1. An indirect heater for heating an object to be heated in a container having a paddle-type or screw-type stirring blade inside the container and passing a heat medium through a jacket of the container to heat the blood powder. A sterilization method, in which the initial water content is 3 to 12% by weight and the undenatured dry blood component of 20 mesh or less is filled in the container of the indirect heater so that the filling rate with respect to the internal stirring blade is 50 to 100%. A method for sterilizing blood meal, which comprises filling and sterilizing blood meal by heating the undenatured dry blood component to 90 to 110 ° C while continuously or intermittently ventilating the inside of the container. 2. The indirect heater is filled with a dried blood component in a container so that the filling rate of the stirring blade inside the container is 80 to 100%. The method for sterilizing blood powder described. 3. The method for sterilizing blood powder according to claim 1, wherein the undenatured dried blood component is blood or a dried blood component thereof, the temperature of which is kept at 50 ° C. or lower. 4. The method for sterilizing blood powder according to claim 1, wherein the undenatured dry blood component is crushed to 60 mesh or less. 5. The method for sterilizing blood powder according to claim 1, wherein the undenatured dry blood component is dry plasma, dry serum, dry blood cells or dry whole blood. 6. Ventilation in the container is 0.02 per 1 g of dried blood components.
The method for sterilizing blood powder according to claim 1, wherein the method is performed by passing a gas of 0.2 Nl / min through the container. 7. The method for sterilizing blood powder according to claim 1 or 6, wherein ventilation in the container is performed by passing a gas heated to 110 ° C. or lower through the container. 8. The method for sterilizing blood powder according to claim 1, 6, or 7, wherein the gas passed through the container for ventilation is air.