JPH0365949B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for transesterification of oils and fats using lipase. Specifically, the present invention relates to a reaction method in which transesterification of oils and fats using lipase is carried out in two steps: a hydrolysis reaction and an ester synthesis reaction. Transesterification of oils and fats is an important technology along with hydrogenation in the production of processed oils and fats. Conventional transesterification reactions are carried out in the presence of inorganic catalysts such as sodium metal, but such chemical methods have the drawback of low regioselectivity for the binding site of the fatty acid to be exchanged. On the other hand, lipase (EC 3113), which is an enzyme that hydrolyzes fats and oils, is known to catalyze not only hydrolysis reactions but also ester synthesis reactions [M. Iwai, Y. Tsujisaka, J. Fukumoto, J. .Gen.
See Appl. Microbiol. 10 , 13, (1964)]. The transesterification reaction of fats and oils using lipase has the advantage of not only the substrate specificity of the enzyme and high selectivity such as positional specificity, but also the fact that the reaction proceeds at room temperature and pressure, so it is also useful from the viewpoint of energy and resource conservation. This is to be expected. It is generally accepted that enzymatic reactions are carried out in an aqueous solution, but in the case of transesterification of fats and oils using lipase, in a reaction system with a relatively large amount of water, the hydrolysis reaction takes precedence, and it is difficult to obtain a preferable reaction product. is difficult. Therefore, the transesterification reaction of fats and oils using conventionally known lipases is carried out in a reaction system with extremely low moisture content. For example, Tokukai Akira
No. 55-71797 describes a method in which the amount of water present in the reaction system is 0.18% by weight or less based on the substrate. Further, JP-A-52-104506 describes a method in which water is added in the presence of a small amount of water, or in the presence of 0.2 to 1% by weight based on the substrate. However, in a reaction system with extremely low water content, such as in the conventionally known method described above, the enzyme is not sufficiently hydrated and cannot take the optimal structure for reaction, so the enzyme is not fully activated and the reaction does not occur. The speed is also very slow. Further, in preparing the enzyme composition, a complicated drying operation is required to remove excess water from the enzyme composition. For this reason, deactivation of the enzyme due to drying is unavoidable, and adjustments to drying time and moisture content are highly empirical, and stable reaction operations cannot be expected. Further, in repeated use of an enzyme composition, in a system with extremely low water content, the water content in the enzyme composition gradually decreases, so that the enzyme activity gradually declines. For this reason, it is necessary to re-add a very small amount of water before the reaction, but it is extremely difficult to control the amount. As mentioned above, while the transesterification reaction of fats and oils using lipase has advantages over chemical methods using inorganic catalysts, it also has many problems, and these are difficult to achieve for industrial use. It is necessary to solve the problems technically. The purpose of the present invention is to fully activate the lipase in the reaction system, increase the reaction rate to the extent that industrialization is possible, and achieve a stable reaction in order to achieve industrial utilization of the transesterification reaction of oils and fats using lipase. The goal lies in the development of reaction operations to maintain this. Furthermore, another object of the present invention is to prevent inactivation of lipase within the reaction system and to enable effective reuse of lipase, thereby increasing the economic efficiency of the transesterification process. . In order to achieve this objective, the present inventors have conducted intensive research into the transesterification reaction of oils and fats using lipase, and as a result, have discovered a reaction operation method that can maximize the functions of lipase. Ta. Regarding lipase, the pioneering research of Tsujisaka, Iwai et al. [for example, (1) J.Gen.Appl.Microbiol. 10 , 13,
(1964), (2)Biochem.Biophys.Acta. 489 , 415
(1977), (3) ibid, 575 , 156, (1979), and (4)
Agric.Biol.Chem. 40 , 655, (1976), etc.], it has been demonstrated that it has regiospecificity and can be used as a catalyst for ester synthesis reaction, which is the reverse reaction of hydrolysis. Among them, the positional specificity of glycerol in ester synthesis is consistent with the positional specificity in hydrolysis, and in glyceride synthesis from glycerol and fatty acids by lipase, the water content in the reaction system controls the final synthesis rate. It has been experimentally proven that Based on these facts, the present inventors analyzed the transesterification reaction of oils and fats using reaction engineering, and as a result, they found that the transesterification reaction rate r of fats and oils is basically expressed by the following equation. I found it. r=k[DG][FA] Here, k is the overall reaction rate constant, [DG] is the diglyceride concentration, and [FA] is the fatty acid concentration. Further, k largely depends on the water content in the reaction system. Regarding the transesterification reaction rate of fats and oils, there have been few kinetic research reports to date. The present inventors conducted basic research and examination on the rate of transesterification of oils and fats using a simplified system, that is, a system consisting of trilaurin and capric acid. As a result of computer-based analysis using reaction rate equations based on all possible reaction paths that correspond to changes in composition over time, it was found that a reaction in which triglycerides and fatty acids directly exchange fatty acid groups and generate new triglycerides cannot occur. It was concluded that no.
On the other hand, assuming a reaction pathway in which a new triglyceride is generated by esterification of diglyceride and fatty acid, that is, assuming that diglyceride is an intermediate in the transesterification reaction, the experimental values and calculated values agree very well, and the above basic We were able to derive a reaction rate equation. That is, based on the knowledge that water, diglyceride, and fatty acids are essential for the transesterification reaction of oils and fats by lipase, the present inventors further improved the reaction efficiency by controlling the water content of the reaction system. The present invention was completed by achieving an improvement in product yield. The requirements for the configuration of the present invention are based on the knowledge that diglyceride is an intermediate in the transesterification reaction of oils and fats, and actively incorporates diglyceride, which has traditionally been an undesirable byproduct in the transesterification reaction of oils and fats, into the reaction. Moreover, it is based on artificially controlling the reaction equilibrium. The method for transesterification of fats and oils using lipase of the present invention is characterized in that the transesterification reaction of fats and oils is carried out in two stages, and the first stage reaction is a hydrolysis reaction of fats and oils using lipase. The second stage reaction is mainly a glyceride ester synthesis reaction using lipase. Incidentally, the two-stage reaction described above can be performed in a continuous operation. Moreover, in order to increase the reaction yield, a multi-stage tank type operation can also be adopted. In the method of the present invention, it is preferable to carry out the reaction in a system to which a relatively large amount of water is added in the first stage reaction, that is, the reaction stage mainly consisting of the hydrolysis reaction. In other words, water should be added in an amount of 0.01 part by weight or more, preferably 0.02 part by weight or more, per 1 part by weight of fats and oils, and by adding water in an amount within this range, the temperature at which normal enzymatic reactions proceed is 20 to 20. By mixing and stirring at 50 DEG C., the reaction reaches equilibrium in 1 to 4 hours, and a reaction product having a diglyceride content of 15 to 50% by weight based on the total glyceride is obtained. The optimal amount of water is 0.02 to 0.10 parts by weight per 1 part by weight of fats and oils, and by using a system containing water within this range, the diglyceride content will be 20 to 0.10 parts by weight relative to the total glyceride.
40% by weight of reaction product is obtained. Next, in the second stage reaction, that is, the reaction stage mainly consisting of ester synthesis reaction, the fatty acid for the purpose of transesterification is added to the reaction product of the first reaction, and
Mix and stir while maintaining the temperature. By adding the fatty acid, the reaction of the system rapidly shifts from the hydrolysis reaction to the ester synthesis reaction, and the diglyceride produced in the first stage reaction is esterified by the ester synthesis reaction to obtain the desired triglyceride. The lipase used in the method of the present invention includes:
Lipases having 1,3-position specificity for triglycerides are preferred, and suitable lipases include Rhizopus delemar, Rhizopus delemar,
Examples include Rhizopus japonicus. In a more preferred method of the present invention, in order to achieve selective transesterification, the proportion of 1,2(2,3)-diglyceride in the diglyceride produced in the first stage reaction, that is, the hydrolysis reaction is 70% by weight. % or more, more preferably 90% or more by weight. Diglycerides often have unstable structures that can undergo acyl group transfer reactions, so it is desirable to keep the hydrolysis reaction temperature below 40°C, and the reaction time should also be kept under the reaction temperature.
When the temperature is 40°C, it is desirable to do so within 10 hours. A more preferred method of the present invention is characterized in that water in the reaction system is removed in the second stage reaction, that is, the ester synthesis reaction stage. In the ester synthesis reaction stage, the addition of fatty acids causes a shift in the reaction equilibrium, but the ester synthesis reaction rate is gradually slowed down by further removing water in the reaction system. In order to remove moisture within the reaction system during the ester synthesis reaction step, dry inert gas is vented into the reaction system and then exhausted to the outside of the reaction system, thereby effectively entraining and removing the moisture within the reaction system. I can do it. The inert gas may be any gas such as nitrogen gas, argon gas, helium gas, etc., as long as it is non-explosive and non-reactive with oils and fats. Ventilation into the reaction system can be carried out by bubbling into the liquid phase in the reactor or by blowing into the gas phase. In the removal of entrained moisture by inert gas ventilation, the exhausted mixed gas is passed through a condenser cooled to below the freezing point of water by a refrigerant, and the water vapor contained in the mixed gas is trapped as ice and converted into inert gas. Water vapor is completely separated. The separated inert gas can be reused by further refluxing it into the reaction system. In addition, in the method of the present invention, the amount of lipase used is 20 to 10,000 U per fat or oil serving as a substrate.
g is desirable, more preferably 100 to 1000 U/g
It is. However, the activity unit (U) of the enzyme is 5 ml of olive oil emulsion and 4 ml of 0.1M phosphate buffer.
When the enzyme was added and the reaction was carried out at 37°C for 30 minutes, one activity unit (U) was defined as each fatty acid produced corresponding to 0.06 ml of a 0.05N aqueous sodium hydroxide solution. The same applies to the enzyme activity units in the Examples shown below. Furthermore, it is desirable to coexist a carrier for the purpose of stabilizing the lipase and measuring its dispersibility. As the carrier,
Inorganic carriers such as diatomaceous earth, activated carbon, gypsum, and zeolite, organic carriers such as cellulose, chitosan, and chitin, or inorganic-organic composite carriers are used. The amount of fatty acid added in the second reaction (ester synthesis reaction) step of the method of the present invention is preferably 0.4 to 2.0 parts by weight per 1 part by weight of fats and oils.
As the fatty acid, linear saturated or unsaturated fatty acids having 2 to 22 carbon atoms can be used, such as palmitic acid, stearic acid, oleic acid, etc. Furthermore, in addition to adding a predetermined amount of the fatty acid in its entirety at once, it is also possible to use a method in which it is added gradually as the reaction progresses. When using stearic acid, palmitic acid, etc., which have high melting points, as added fatty acids, the reaction temperature may become non-uniform. In such cases, dissolve the fatty acids in an organic solvent that is inactive to lipase. The reaction can be carried out in a homogeneous system. Examples of this type of organic solvent include n-hexane, industrial hexane, petroleum ether, etc., and can be used in an amount of 1 to 10 parts by weight per 1 part by weight of fatty acid. The reaction temperature in the present invention is 20 to 70°C in both the first stage reaction (hydrolysis reaction) and the second stage reaction (ester synthesis reaction), which is the same as in normal enzyme reactions.
It can be done with However, in the first reaction stage, since the acyl group transfer reaction of the produced diglyceride depends on the reaction temperature, it is not appropriate to carry out the reaction at a temperature of 50°C or higher, and it is desirable to carry out the reaction at a temperature of 40°C or lower. As mentioned above, in the method of the present invention, the transesterification reaction of oils and fats is configured as a two-step reaction of hydrolysis reaction and ester synthesis reaction, so the reaction is more efficient than a reaction system that uses a trace amount of water. Therefore, compared to the conventional one-stage reaction in which the reaction rate had to be sacrificed in order to keep the partial glyceride produced by hydrolysis low, the reaction rate is dramatically improved and at the same time the final product is This is an innovative reaction operation method that can reduce the content of partial glycerides such as diglycerides and monoglycerides. Increasing the reaction rate not only reduces reactor operation time and enables an efficient and highly productive process, but also reduces the residence time of the enzyme or enzyme-containing composition in the reactor, thereby increasing the reaction rate. It also has the advantage that deactivation of the enzyme or change in shape of the enzyme-containing composition caused by stress or physical changes on the surface caused by stirring in the container can be reduced. Further, the method of the present invention eliminates the need for the complicated labor involved in drying operations in the preparation of conventional enzyme-containing compositions, and completely avoids deactivation of enzymes due to excessive drying.
Furthermore, in conventional methods that use extremely small amounts of water, it was essential to strictly control the initial water content in order to suppress hydrolysis, but in the method of the present invention, the initial water content is in the range of 3 to 10% by weight based on the fats and oils that serve as the substrate. If the water content is , the water can be easily removed by the water removal operation in the ester synthesis reaction stage of the second stage reaction, which is very effective in terms of operability. Furthermore, the method of the present invention does not require strict control of water content even when the enzyme-containing composition is repeatedly used, and the enzyme can be reactivated by adding water to the reaction system in the second and subsequent reactions. This allows for stable reaction operation as it is possible to maintain high enzymatic activity at all times. Moreover, according to the method of the present invention, the enzyme can be reused five or more times, and the economic efficiency of the process can be dramatically improved. EXAMPLES Next, the present invention will be explained in more detail with reference to Examples, but the present invention is not limited to these Examples. Experimental Example 1 8 g of chitosan (manufactured by Kyowa Yushi Kogyo Co., Ltd., trade name Fronac N) was added and mixed in 60 g of a 10% acetic acid aqueous solution to form a chitosan acetate gel, and then 440 g of water and 32 g of Celite were added to the gel. After adding the mixture to make a homogeneous mixture, this was mixed dropwise into 2000 g of acetone, and the insoluble matter was recovered by centrifugation.The insoluble matter was then added and mixed in 1000 g of acetone, filtered, and air-dried. The carrier was deacetonized and dried under vacuum to obtain a carrier consisting of chitosan acetate-celite. Next, Rhizopus redemer (Rhizopus
delemar) derived lipase (98000U/g) 103mg
was dissolved in 0.5 g of water and adsorbed onto 2.0 g of the above chitosan acetate-Celite carrier to obtain an immobilized enzyme. The immobilized enzyme was added to a mixture of 38 g of palm soft part oil and 120 g of n-hexane, and the mixture was stirred in a closed reaction vessel at a reaction temperature of 40°C to carry out a hydrolysis reaction. The reaction mixture was separated over time and subjected to synchrography using IATROSCAN TH-10 [JJSzakasits etal., Anal.
Chem., 45 , 351 (1970), M. Tanaka et al.,
Lipids 15 (10), 872 (1980), etc.], 1,
3-diglyceride, 1,2(2,3)-diglyceride, fatty acids, triglycerides, etc. were analyzed.
However, the developing solvent in the synchrography method is benzene: chloroform: formic acid = 70:30:2.
was used. These results are shown in FIG. 1st
In the figure, TG is triglyceride, 1,2(2,3)-
DG is 1,2(2,3)-diglyceride, 1,3-
DG represents 1,3 diglyceride, MG represents monoglyceride, and FFA represents fatty acid. The lipase derived from Rhizopus deremer used in this experiment has the specificity of selectively hydrolyzing the 1-position and the 3-position. Therefore, as is clear from FIG. 1, only 1,2(2,3)-diglyceride is produced at the initial stage of the reaction. When the reaction time becomes longer, 1,
The proportion of 3-diglyceride increases, but this
1,2 (2,3) rather than the effect of the lipase
It is considered that -diglyceride was converted to 1,3-diglyceride by a non-enzymatic acyl group transfer reaction. Regarding such a transfer reaction, there is a report by Okumura et al. [S. Okumura, M. Iwai, T.
Tsujisaka, Agric.Biol.Chem., 45 , 185 (1981)
reference〕. If such non-enzymatic acyl group transfer reaction is not considered, as shown in Figure 1, approximately 3
It can be seen that the hydrolysis reaction reaches equilibrium in about hours. Naturally, when the reaction time is further lengthened, the proportion of 1,3-diglyceride increases. Moreover, when the reaction temperature is further increased, the rate of non-enzymatic acyl group transfer reaction naturally increases. When a fatty acid is added after the first stage reaction mainly consisting of a hydrolysis reaction to perform a second stage reaction mainly consisting of an ester synthesis reaction, 1,3-diglyceride is converted into 1,3-diglyceride.
Undesirable as a substrate for synthesis by lipases with 3-regiospecificity. Therefore, it is desirable to stop the hydrolysis reaction at a stage when the production rate of 1,3-diglyceride is small and start the next ester synthesis reaction stage. For this reason, it is more desirable to add the fatty acid and enter the ester synthesis reaction stage at the time when the hydrolysis reaction almost reaches equilibrium, or slightly before reaching equilibrium. Experimental Example 2 In this experimental example, the influence of the amount of water added in the hydrolysis reaction stage on the reaction equilibrium was investigated. The immobilized enzyme was prepared in the same manner as in Experimental Example 1 except for the amount of water added. Further, the reaction conditions and the like were the same as in Experimental Example 1. Moisture content (based on substrate weight) 1.3%,
For the cases of 2.6%, 5, 3% and 10.5%, the time required for the hydrolysis reaction to reach equilibrium (hr) and the diglyceride content (% by weight relative to the total glyceride) in the reaction mixture at equilibrium are calculated, respectively. The results are shown in Table 1. As is clear from Table 1,
It can be seen that the equilibrium state of the hydrolysis reaction is determined by the initial water content, and as the water content is further increased, the DG (diglyceride) content in the equilibrium state increases further.

[Table] Example 1 Under the same reaction conditions as in Experimental Example 1, the first stage reaction (hydrolysis reaction) was carried out for 3 hours. Next, 57 g of stearic acid (NAA-180, manufactured by NOF Corporation) and 165 g of n-hexane were added, and a second stage reaction (ester synthesis reaction) was carried out at 40°C. The reaction mixture was fractionated over time, and a triglyceride fraction was fractionated by column chromatography (column chromatography conditions: carrier, Florisil, developing solvent, n-
Hexane:ethyl ether = 85:15). The solid fat content (SFC) of the separated triglyceride fraction was measured. The refining conditions for SFC measurement are as follows: After completely liquefying the fat and oil, leave it at 0℃ for 30 minutes to solidify, leave it at 20℃ for 2 hours, and then leave it at 30℃ and 20℃ for 1 hour and 2 hours, respectively. This was done by repeating this seven times. SFC is measured using the conventional method (A.
OCSRecomended Practice Cd 16−81 Solid
Fat Content) was carried out using PRAXIS MODEL SFC-900.
FIG. 2 shows the SFC of the triglyceride fraction at reaction times of 0, 4, 8, 12, and 20 hours in the second stage reaction (ester synthesis reaction). As is clear from FIG. 2, the physical properties of the triglyceride hardly changed after the reaction time of 8 hours. Therefore, it can be seen that when producing a cocoa butter substitute, it is sufficient to complete the reaction in about 8 hours, separate the triglyceride fraction, and separate the medium melting point triglyceride by solvent fractionation or the like. Comparative Example 1 To the same mixture of palm soft part oil and n-hexane as in Experimental Example 1, 57 g of stearic acid (NAA-180, manufactured by NOF Corporation) and n-hexane were added along with the addition of immobilized enzyme.
Experimental example 1 except for adding 165g of hexane
The transesterification reaction was carried out under the same reaction conditions.
The reaction mixture was fractionated over time, and in the same manner as in Example 1, the triglyceride fraction was fractionated by column chromatography and the SFC was measured. These results are shown in FIG. As is clear from Figure 3,
Compared to the results of Example 1 (FIG. 2), the change in physical properties over time (SFC) is very slow. Example 2 and Comparative Examples 2 and 3 The transesterification reaction of fats and oils was carried out in the following manner using the apparatus shown in the flow sheet in FIG. An immobilized enzyme prepared by dissolving 38 g of palm soft part oil, 103 mg of lipase derived from Rhizopus delemer (98000 U/g) in 2.0 g of water, and adsorbing this onto 2.0 g of the same carrier as in Experimental Example 1, and 120 g of n-hexane.
Stirrer 1 in closed reactor A for 2 hours at 40 °C with
The first stage reaction (hydrolysis reaction) was carried out by stirring under a. Next, stirring was temporarily stopped, 34.2 g of stearic acid (NAA-180, manufactured by NOF Corporation) was added, and stirring was resumed. From reservoir D to pump C
Dry nitrogen is blown through the desiccant packed bed B to create a gas phase part 2 in which a gas-liquid equilibrium relationship is established.
The water content in the reaction system was gradually lowered by exhausting the entrained inert gas containing water vapor out of the reaction system (ester synthesis reaction of the second stage reaction).
The average residence time of the inert gas during this second stage reaction was about 3 seconds. The entrained inert gas containing n-hexane and water vapor passes through the surface condenser F cooled to around -20℃ with dry ice, where the n-hexane liquefies, the water vapor turns into ice, and the gas-liquid-solid transition occurs. The liquefied n-hexane was refluxed to reactor A. After the reaction was completed, stirring was stopped and the product was collected. The reaction product is J. Blum (J.Blum)
[Lipid, 5, 601, (1970)], trimethylsilylation was performed using hexamethyldisilazane (HMDS) and trimethylchlorosilane (TMOS) (manufactured by Wako Pure Chemical Industries, Ltd.), and the reaction was performed by temperature-programmed gas chromatography. analyzed. The results are shown in Table 2. As shown in Table 2, in the method according to the present invention (Example 2), 24.6% by weight of diglyceride was produced by the hydrolysis reaction in the first stage reaction, but the transesterification reaction and ester synthesis in the second stage reaction Due to the reaction, diglyceride gradually decreases, and after 8 hours,
It decreased to 11.5% by weight, and 7.4% after 12 hours.
% by weight. On the other hand, as a comparative example, the same immobilized enzyme as in Example 2 was used, and stearic acid was added from the beginning (Comparative Example 2), and stearic acid was added from the beginning and a small amount of water (relative to the substrate) was used. Table 2 shows the results of the reaction using 0.3% by weight (Comparative Example 3).
In the case of Comparative Example 2, that is, in the case of the so-called one-stage reaction in which stearic acid was added from the beginning, the transesterification progressed, but the rate was slow, and the diglyceride once produced showed a tendency to increase until the reaction equilibrium was reached. However, no decrease in diglyceride was observed due to re-esterification. In addition, in the case of Comparative Example 3, that is, when a very small amount of water was added to the reaction system for the purpose of suppressing the formation of diglyceride as much as possible, as is clear from Table 2, the reaction rate was very slow, and the reaction of the present invention was Compared to the method, the reaction rate is less than 1/7, which means that it is virtually impossible to use as an industrial process. Furthermore, if the reaction time is prolonged due to fear of the formation of diglyceride, the enzyme activity is significantly reduced, and it is almost impossible to reuse the enzyme agent recovered after the reaction is completed.

【table】

[Table] Example 3 and Comparative Example 4 First stage reaction (hydrolysis reaction) and second stage reaction (ester synthesis reaction) in the same manner as in Example 2
A transesterification reaction consisting of steps was performed, and after the reaction was completed, the immobilized enzyme was collected. To the recovered immobilized enzyme,
Water was adsorbed in an amount equivalent to 5.0% by weight based on the raw material oil. Using the immobilized enzyme, a transesterification reaction consisting of a hydrolysis reaction step and an ester synthesis reaction step was repeated in the same manner as in Example 2. The reaction mixture after 8 hours of the ester synthesis reaction step was trimethylsilylated in the same manner as in Example 2, and analyzed by temperature-rising gas chromatography. On the other hand, as Comparative Example 4, a similar analysis was conducted for a case where the hydrolysis reaction step was not performed and the reaction was performed by adding fatty acids from the beginning. From the results of these analyses, the number of carbon atoms in the triglycerides in the raw material fat and the reaction mixture was determined.
Sum of absolute values of changes in triglyceride with carbon number 50 (C50) and triglyceride with carbon number 54 (C54) (｜△
C50 | + | △C54 |
The analysis results related to the above are shown by polygonal lines 2, respectively. Further, the diglyceride content in the total glycerides in the reaction mixture is also shown in FIG. 5, with the analysis results for Example 3 shown by line 3 and the analysis results for Comparative Example 4 shown by line 4. As is clear from FIG. 5, in the case of Example 3, the reaction rate was very rapid, but in the case of Comparative Example 4,
In the case of , the reaction rate is significantly reduced by repeated reactions.

[Brief explanation of drawings]

Figure 1 is a graph showing changes over time in each component in the reaction mixture in the hydrolysis reaction of Experimental Example 1, and Figure 2 is a graph showing triglycerides in the reaction mixture in the second reaction (ester synthesis reaction) stage of Example 1. A graph showing changes over time in the SFC of the fractions. Figure 3 is a graph showing changes over time in the SFC of the triglyceride fraction in the reaction mixture in the transesterification reaction of Comparative Example 1. Figure 4 is a graph showing changes over time in the SFC of the triglyceride fraction used in Example 2. FIG. 5 is a flow sheet of an apparatus suitable for carrying out the present invention, and shows the change in the amount of triglyceride in the reaction mixture and the proportion of triglyceride in the total glyceride in the reaction mixture in the repeated reactions of Example 3 and Comparative Example 4. It is a graph showing changes in diglyceride content. A...reactor, B...desiccant packed bed, C...pump,
D... Nitrogen reservoir, E... Nitrogen cylinder, F... Condenser, 1a... Stirrer, 1... Liquid phase part, 2... Gas phase part.

Claims (1)

[Scope of Claims] 1. It is characterized by being composed of two consecutive reactions: a first stage reaction mainly consisting of a hydrolysis reaction of oils and fats, and a second stage reaction mainly consisting of an ester synthesis reaction. Method for transesterification of oils and fats using lipase. 2. The method for transesterification of oils and fats using lipase according to claim 1, wherein the lipase is a lipase having 1,3-regiospecificity. 3. The method for transesterification of oils and fats using lipase according to claim 1 or 2, wherein the first stage reaction is a reaction that yields 15 to 50% by weight of diglyceride based on the total glyceride. 4. The method for transesterifying fats and oils using lipase according to claim 1 or 2, wherein the first stage reaction is a reaction that yields 20 to 40% by weight of diglycerides based on the total glycerides. 5 1,2 (2,3) in which the diglyceride obtained by the first stage reaction is 70% by weight or more of the total diglyceride
- is a diglyceride containing diglyceride,
A method for transesterifying fats and oils using a lipase according to any one of claims 1 to 4. 6 1,2 (2,3) in which the diglyceride obtained by the first stage reaction is 90% by weight or more of the total diglyceride
- is a diglyceride containing diglyceride,
A method for transesterifying fats and oils using a lipase according to any one of claims 1 to 4. 7 Claims 1 to 6, wherein the second stage reaction is a reaction in which a fatty acid is added to perform an ester synthesis reaction.
A method for transesterification of oils and fats using lipase according to any one of Items 1 to 3. 8 The amount of fatty acids added is 0.4 per part by weight of fats and oils.
A method for transesterifying fats and oils using lipase according to claim 7, wherein the amount is 2.0 parts by weight. 9. A method for transesterification of oils and fats using lipase according to any one of claims 1 to 8, wherein in the second stage reaction, water in the reaction system is removed. 10 Moisture removal is carried out by continuously or intermittently passing a dry inert gas into the reaction system and exhausting it outside the reaction system to remove the moisture within the reaction system. 9. A method for transesterification of oils and fats using lipase according to item 9. 11. The method for transesterification of oils and fats using lipase according to claim 10, wherein the gas exhausted outside the reaction system is passed through a condenser to separate and remove moisture, and then refluxed into the reaction system.