JP3550727B2 - Improved chlorohydrin hydrolysis method from protein hydrochloride hydrolyzate - Google Patents

Description

[0001]
[Industrial applications]
The present invention relates to a method for hydrolyzing a chlorohydrin compound contained in a protein hydrolyzate. More specifically, the present invention relates to a method for hydrolyzing chlorohydrin, in which a hydrolyzate of protein hydrochloride and an alkali are simultaneously dropped and mixed at a given temperature and pH so that the temperature of the mixed solution is maintained after the dropping.
[0002]
[Prior art]
Conventionally, protein hydrochloride hydrolyzate is produced through steps of high-temperature hydrolysis of protein raw material with concentrated hydrochloric acid, neutralization with an alkali to about pH 5, filtration of insoluble substances such as fumes, and concentration. During these steps, steam distillation, adsorption treatment with a resin or activated carbon, high-temperature treatment of a decomposition solution (pH 4 to 9), and the like may be performed (Japanese Patent Publication No. 47-24748).
[0003]
It is known that chlorohydrin compounds such as monochloropropanediol are generated when a protein material is hydrolyzed with hydrochloric acid. However, it has recently been found that these chlorohydrin compounds contain undesirable substances.
[0004]
It has long been known that a chlorohydrin compound is decomposed by an alkali such as sodium hydroxide. For example, on page 389 of the textbook "Alcoholes" (Reinhold Book Corporation) published in 1968, it was found that monochloropropanediol (MCP) produces 2,3-epoxypropanol from alkali such as sodium hydroxide, It is described that epichlorohydrin is produced from propanol (DCP). Also, on page 95 of the textbook of organic chemistry “INTRODUCTION TO ORGANIC CHEMISTRY” (Maruzen) published in 1957, as a method for producing glycerol, 2,3-epoxypropanol was produced using soda lime as an alkali for MCP. , A reaction that produces glycerol upon hydrolysis. It is also shown in the text of Japanese Patent Publication No. 62-224256 that "30 to 50 ppm of DCP can be destroyed by excessive neutralization, particularly by adding caustic soda."
[0005]
[Problems to be solved by the invention]
In order to carry out the process on an industrial production facility scale, shortening the residence time of the reaction tank, that is, shortening the liquid sending and reaction times leads to an improvement in productivity. For example, in the case of a tank of about 100 m ³ , it usually takes several hours to feed the liquid in the tank. In addition, heat is generated when the acid decomposition solution and the alkali are mixed, but the heat generated may cause bumping. In an industrial plant, the usual method is to pump liquid until a certain amount is fed into a tank, and to prevent bumping, a skilled worker must constantly monitor. From such a problem, a method for reducing the residence time and a method for easily controlling the temperature of the reaction solution have been desired.
[0006]
[Means for Solving the Problems]
The present inventors have simultaneously sent the protein hydrolyzate hydrolyzate and the alkali to the reaction tank so as to maintain the temperature and pH within a certain range, and after the completion of the liquid transfer, continuously maintain the temperature of the mixed solution, thereby They found that they could solve the problem.
More specifically, the method of the present invention is a method for simultaneously sending and mixing a protein hydrolyzate hydrolyzate and an alkali, thereby shortening the time required to feed the raw material liquid to the reaction tank, and further reducing the temperature during the liquid sending and mixing. And maintaining the pH within a certain range, decomposing the chlorohydrin compound even during the feeding and mixing time, and further decomposing the chlorohydrin compound by continuously maintaining the temperature of the mixed solution after the completion of mixing. The present invention relates to a method for hydrolyzing a chlorohydrin compound in a protein hydrolyzate.
[0007]
In order to send the protein hydrolyzate hydrolyzate and the alkali, they are mixed by a mixing means such as a line mixer and sent to the reaction tank, or sent to the reaction tank from separate inlets. At that time, the ratio of the protein hydrochloride hydrolyzate to the alkali is set so that the pH of the mixed solution falls within a desired range. In addition, protein hydrochloride hydrolyzate (the one used in the method of the present invention may be an unneutralized solution immediately after acid decomposition or a solution after neutralization, but an unneutralized solution is more often used. ) And an alkali generate heat due to the heat of neutralization and the heat of dilution. However, if the mixture does not boil during mixing, the temperature of the hydrolyzed protein hydrochloride and the alkali before mixing and the mixing ratio can be arbitrarily set. Further, if desired, cooling and heating can be combined to achieve a desired temperature. When the hydrolyzate of protein hydrochloride and the alkali have been charged into the reaction tank in this way, the pH of the mixture is maintained at a predetermined pH and temperature by performing readjustment, fine adjustment, heating, cooling, etc., as necessary.
[0008]
In order to promote the decomposition of the chlorohydrin compound, the mixture is preferably kept at a high temperature and a high pH, more preferably at a temperature of 70 ° C. or more and a pH of 8 or more.
[0009]
As described above, the temperature of the mixed solution increases due to heat generation. However, if the desired temperature is not reached, the mixed solution can be heated. It is also possible to heat the protein hydrolyzate hydrolyzate or alkali after mixing only one, both, or a mixer. For heating, any means such as a jacket, a coil, steam blowing, an external heat exchanger, and the like can be used. If the temperature rises too high, it can be cooled.
[0010]
As the hydrolyzed protein hydrochloride used in the present invention, a hydrolyzed hydrochloride obtained from any protein source such as yeast protein, animal protein, and plant protein can be used.
[0011]
As the alkali used for neutralizing the protein hydrochloride hydrolyzate, any one of organic alkali compounds such as organic amines, inorganic alkali compounds such as ammonia, calcium hydroxide, sodium hydroxide, and sodium carbonate can be used alone or in combination. Can be used. Usually, it is often desired that the final product of the protein hydrolyzate contains salt, and in such a case, an inorganic alkali sodium salt is used.
[0012]
After the mixture has been charged into the reaction tank, the mixture can be held for a predetermined time if necessary.However, the temperature and time to be held are arbitrarily set so that the chlorohydrin compound has a desired concentration. It is possible to decide. Since it is generally preferable that the chlorohydrin compound is not detected, it is desirable to maintain the mixture at 70 ° C. or more and the pH at 8 or more until the chlorohydrin compound contained in the mixture becomes 1 ppm or less. In general, the decomposition rate increases as the temperature increases, and it is therefore preferable to maintain the temperature at 70 ° C. or higher. From the viewpoint of the decomposition of the chlorohydrin compound, the decomposition for a long time is good, but in a pH range higher than weak alkalinity, it can be usually carried out in 20 hours or less.
[0013]
【Example】
Hereinafter, the present invention will be described in more detail with reference to examples.
[0014]
Example 1
To 2620 g of soybean flakes and 375 g of gluten meal, 2070 g of 35% hydrochloric acid and water were added and mixed until the volume became 6 L. This mixture was heated in an autoclave at 105 ° C. for 30 hours to carry out a hydrolysis reaction. This hydrolyzate was filtered and used in subsequent experiments. The digested filtrate (hereinafter abbreviated as the digested filtrate) contained 3-monochloropropanediol (3MCP) at a concentration of 47.5 ppm, TN at 4.36 g / dl, and amino acids at a concentration of 23.9 g / dl.
The decomposition filtrate and a 31% NaOH aqueous solution were continuously dropped and mixed into a 1 L separable flask (equipped with a stirrer and a condenser) heated in a hot water bath over 2 hours. The dripping amounts were 500 ml and 235 ml, respectively. During the addition, the temperature inside the reaction tank was 95 ° C., and there was no bumping. The pH at the end of the dropwise addition was 9.2 (measured by cooling to 30 ° C.), and 3MCP was reduced to 0.4 ppm. After the dropping, the temperature was kept at 98 ° C., and after 30 minutes (2 and a half hours from the start of dropping), 3MCP was not detected. The decrease curve of 3MCP is shown in FIG. (The detection limit of 3MCP is 0.05 ppm.)
[0015]
Example 2
The decomposition filtrate and a 31% NaOH aqueous solution were continuously dropped and mixed into a 1 L separable flask (equipped with a stirrer and a condenser) heated in a hot water bath over 2 hours. The drop amounts were 500 ml and 220 ml, respectively. During the addition, the temperature inside the reaction tank was 98 ° C., and there was no bumping. The pH at the end of the dropwise addition was 8.3 (measured by cooling to 30 ° C.), and 3MCP was reduced to 5.3 ppm. When the temperature was maintained at 98 ° C. after the dropping, the 3MCP concentration was 0.2 ppm after 2 hours, and was not detected after 3 hours (5 hours from the start of dropping). The decrease curve of 3MCP is shown in FIG.
[0016]
Comparative Example 1
500 ml of the decomposition filtrate was put into a 1 L separable flask (equipped with a stirrer and a condenser) heated in a hot water bath, and 220 ml of a 31% NaOH aqueous solution was continuously dropped over 2 hours. During the addition, the temperature inside the reaction tank was 98 ° C., and there was no bumping. The pH at the end of the dropwise addition was 8.3 (measured by cooling to 30 ° C.), and the 3MCP concentration was not so reduced, and was 30 ppm. When the temperature was maintained at 98 ° C. after the dropping, the 3MCP concentration after 2 hours was 0.5 ppm, and 0.1 ppm was detected after 3 hours (7 hours from the start of dropping). The decrease curve of 3MCP is shown in FIG.
[0017]
Example 3
A hydrolyzed protein hydrochloride prepared in the same manner as in Example 1 was used as a decomposition solution. Degradation solution 27.6KL, the fed liquid by a pump to the reactor 50m3 of 31% NaOH11.1KL at a flow rate of each ^{35m 3 /Hr,14.2m} 3 / Hr. The pH during feeding was 8.6 and the temperature was constant at 98 ° C. The time required for liquid supply was 47 minutes. When the temperature was further maintained, the 3MCP concentration at the time when 33 minutes had passed from the end of the liquid supply was 3.57 ppm, and the concentration decreased to 0.1 ppm at 133 minutes after the end of the liquid supply (180 minutes after the start of the filling). Progress).
[0018]
Example 4
A hydrolyzed protein hydrochloride prepared in the same manner as in Example 1 was used as a decomposition solution. Degradation solution 27.6KL, the fed liquid by a pump to the reactor 50m3 of 31% NaOH11.1KL at a flow rate of each ^{35m 3 /Hr,14.7m} 3 / Hr. The pH during feeding was 8.9 and the temperature was constant at 98 ° C. The time required for supplying the solution was 47 minutes for the decomposition solution and 45 minutes for 31% NaOH. When the temperature was further maintained, the 3MCP concentration at the point 33 minutes after the end of the liquid supply was 1.67 ppm, and the concentration decreased to 0.1 ppm at the 108th minute from the end of the liquid supply (155 minutes after the start of the filling). Progress).
[0019]
Comparative Example 2
A hydrolyzed protein hydrochloride prepared in the same manner as in Example 1 was used as a decomposition solution. Imposition over decomposing solution 27.6KL 47 minutes 35 m3 / Hr and from 31 min after Zoletile injection from imposition onset of decomposition liquid, the liquid supply pump to 31% NaOH11.1KL reactor, 50 m ³ at a flow rate of ^18m 3 / Hr did. The pH and temperature in the feed increased gradually after the addition of 31% NaOH, and finally reached pH 8.6 and 98 ° C. The time required for liquid supply was 72 minutes. When the temperature was further maintained, the 3MCP concentration at the time when 33 minutes had passed from the end of the liquid supply was 3.74 ppm, and the concentration decreased to 0.1 ppm at 138 minutes after the end of the liquid supply (210 minutes after the start of the filling). Progress).
[0020]
【The invention's effect】
By using the method of the present invention, both the time for feeding the solution to the reaction tank and the time for the decomposition reaction of the chlorohydrin compound can be shortened, and the productivity can be improved. Further, the temperature of the mixed solution can be easily controlled, and the process control can be easily performed.
[Brief description of the drawings]
BRIEF DESCRIPTION OF DRAWINGS FIG. 1 shows a decrease curve and operation time of 3MCP of Example 1, Example 2, and Comparative Example 1.

Claims (2)

The chlorohydrin compound contained in the protein hydrolyzate is decomposed by simultaneously dropping and mixing the protein hydrolyzate and the alkali so that the temperature is 70 ° C. to 100 ° C. and the pH is 8 or more, and then the obtained product is obtained. Maintaining the temperature of the resulting mixture at 70 ° C. or higher and the pH at 8 or higher until the amount of the undecomposed chlorohydrin compound contained in the mixed solution decreases, characterized in that the chlorohydrin compound in the protein hydrochloride hydrolyzate is maintained. Hydrolysis method. The chlorohydrin compound contained in the protein hydrolyzate is decomposed by simultaneously adding the protein hydrolyzate hydrolyzate and the alkali dropwise at a temperature of 90 ° C. to 100 ° C. and at a pH of 8 to 9 to decompose the chlorohydrin compound. Maintaining the temperature of the obtained mixture at 90 ° C. to 100 ° C. and maintaining the pH at 8 to 9 until the amount of undecomposed chlorohydrin compounds contained in the obtained mixture decreases. For hydrolyzing chlorohydrin compounds in water.

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