JP2017214345A - Method for producing sucrose fatty acid ester - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing a sucrose fatty acid ester having high monoester selectivity.SOLUTION: The method for producing a sucrose fatty acid ester comprises: a step of preparing an aqueous solution containing sucrose and a basic catalyst; and a step of producing a sucrose fatty acid ester by mixing the aqueous solution obtained in the preparation step, a fatty acid alkali metal salt and a melted fatty acid ester (excluding palmitic acid ester and stearic acid ester), and heating the mixture while stirring under reduced pressure. The step of producing a sucrose fatty acid ester has an earlier step of removing water from the mixture, and a subsequent step of performing transesterification after the earlier step. In the subsequent step, heating is performed through microwave irradiation such that the temperature of the mixture is below the sucrose decomposition temperature.SELECTED DRAWING: None

Description

  The present invention relates to a method for producing a sucrose fatty acid ester having a high monoester selectivity.

  Conventionally, sugar fatty acid esters are produced by transesterifying sugars and fatty acid esters (see, for example, Patent Document 1).

JP-A-63-1119493

In the production of such sugar fatty acid esters, diesters (di-forms), triesters (tri-forms) and the like are produced together with monoesters (mono-forms), but sucrose fatty acid esters (sugar esters) and Since monoesters of sugar fatty acid esters such as glucose fatty acid esters have excellent characteristics, there has been a demand for producing sugar fatty acid esters so that the monoester content is increased. For example, monoesters of sucrose fatty acid esters are known to have antibacterial properties and heat stability.
In addition, since such monoesters are used in food additives such as emulsifiers, cosmetics, pharmaceuticals, and the like, there has been a demand for producing sucrose fatty acid esters without odor.

  The present invention has been made in the above situation, and an object thereof is to provide a method for producing a sucrose fatty acid ester having a high monoester ratio and no odor.

  As a result of diligent research on the above-mentioned problems, the inventors of the present invention irradiate microwaves and heat them so that they are lower than the decomposition temperature of sucrose. The inventors have found that sugar fatty acid esters can be produced and have completed the invention.

That is, the present invention is as follows.
[1] preparing an aqueous solution containing sucrose and a basic catalyst;
The sucrose fatty acid ester is obtained by mixing the aqueous solution obtained in this step, a fatty acid alkali metal salt, and a fatty acid ester (excluding palmitic acid ester and stearic acid ester), stirring and heating under reduced pressure. A step of generating,
The step of producing the sucrose fatty acid ester has a previous step of removing water from the mixture, and a subsequent step of performing transesterification after the step,
In the subsequent step, a method for producing a sucrose fatty acid ester, wherein the mixture is heated by irradiation with microwaves so that the mixture is lower than the decomposition temperature of the sucrose.
Here, excluding palmitic acid ester and stearic acid ester means to exclude the case where the fatty acid ester is only palmitic acid ester and the case where the fatty acid ester is only stearic acid ester.

[2] The method for producing a sucrose fatty acid ester according to [1], wherein the production target is a sucrose fatty acid ester in which a monoester weight ratio is 60% by weight or more.

[3] The fatty acid ester is a fatty acid ester (except for palmitic acid ester and stearic acid ester) having at least one selected from saturated and unsaturated fatty acids having 8 to 24 carbon atoms as a constituent fatty acid. [1] or [2] A method for producing a sucrose fatty acid ester.

[4] The method further includes the step of producing a fatty acid alkali metal salt by mixing and heating a fatty acid ester and a solution obtained by dissolving an alkali metal salt in a solvent,
The sucrose according to any one of [1] to [3], wherein the fatty acid alkali metal salt used in the step of producing the sucrose fatty acid ester is produced in the step of producing the fatty acid alkali metal salt. A method for producing a fatty acid ester.

[5] The sucrose fatty acid ester according to any one of [1] to [4], wherein in the subsequent step, the mixture is heated so that the temperature of the mixture is 25 ° C. lower than the decomposition temperature and lower than the decomposition temperature. Manufacturing method.

[6] The method for producing a sucrose fatty acid ester according to any one of [1] to [5], wherein in the subsequent step, the mixture is heated so as to increase in temperature.

[7] The method for producing a sucrose fatty acid ester according to any one of [1] to [6], wherein the heating time in the subsequent step is 6 hours or less.

  According to the method for producing a sucrose fatty acid ester according to the present invention, a sucrose fatty acid ester having a high monoester ratio and no odor is obtained by irradiating with microwaves and heating so as to be lower than the decomposition temperature of sucrose. Can be manufactured.

Table showing results of reference examples and comparative examples The graph which shows the time change of the mono-body yield of a reference example and a comparative example, and a mono-body weight ratio. Table showing results of reference examples and comparative examples The graph which shows the time change of the mono-body yield of a reference example and a comparative example, and a mono-body weight ratio. Table showing results of Examples and Comparative Examples The graph which shows the time change of the mono-body yield of an Example and a comparative example, and a mono-body weight ratio. Table showing results of Examples and Comparative Examples The graph which shows the time change of the mono-body yield of an Example and a comparative example, and a mono-body weight ratio. Table showing results of Examples and Comparative Examples The graph which shows the time change of the mono-body yield of an Example and a comparative example, and a mono-body weight ratio. Table showing results of Examples and Comparative Examples The graph which shows the time change of the mono-body yield of an Example and a comparative example, and a mono-body weight ratio.

  A step of producing a fatty acid alkali metal salt by mixing and heating a fatty acid ester and a solution in which an alkali metal salt is dissolved in a solvent; and a step of preparing an aqueous solution containing sucrose and a basic catalyst; The aqueous solution obtained in the step, the fatty acid alkali metal salt produced in the step of producing the fatty acid alkali metal salt, and the fatty acid ester are mixed, stirred under reduced pressure and heated to produce sucrose fatty acid ester. And a method for producing a sucrose fatty acid ester. The step of producing the sucrose fatty acid ester has a preceding step of removing water from the mixture and a subsequent step of transesterification after the step. In the subsequent process, the mixture is heated so as to be lower than the decomposition temperature of sucrose by irradiation with microwaves.

  The fatty acid ester used in the step of producing the fatty acid alkali metal salt may be, for example, a fatty acid alkyl ester or a fatty acid polyhydric alcohol ester. The constituent fatty acid of the fatty acid ester is not particularly limited, and may be, for example, a short chain fatty acid having 7 or less carbon atoms, a medium chain fatty acid having 8 to 10 carbon atoms, or a long chain fatty acid having 12 or more carbon atoms. The constituent fatty acid may be, for example, a fatty acid having 8 to 24 carbon atoms, a fatty acid having 8 to 22 carbon atoms, a fatty acid having 8 to 20 carbon atoms, The number may be 8 to 18 fatty acids. The fatty acid may be a saturated fatty acid or an unsaturated fatty acid. The constituent fatty acid of the fatty acid ester may be, for example, a fatty acid ester having at least one selected from saturated fatty acids having 8 to 12 carbon atoms and saturated and unsaturated fatty acids having 14 to 24 carbon atoms as constituent fatty acids. Further, the unsaturated fatty acid may be a monounsaturated fatty acid (monoene fatty acid) or a polyunsaturated fatty acid (polyene fatty acid). Examples of fatty acids include caprylic acid, capric acid, lauric acid, myristic acid, myristoleic acid, palmitic acid, palmitoleic acid, stearic acid, oleic acid, linoleic acid, linolenic acid, eleostearic acid, arachidic acid, and mead acid. Arachidonic acid, behenic acid, lignoceric acid, nervonic acid or erucic acid.

  The alkyl group in the fatty acid alkyl ester may be, for example, a linear or branched alkyl group having 1 to 5 carbon atoms. Examples of the alkyl group having 1 to 5 carbon atoms include methyl group, ethyl group, n-propyl group, isopropyl group, cyclopropyl group, n-butyl group, isobutyl group, sec-butyl group, t-butyl group, and cyclobutyl. A group, a pentyl group, an isopentyl group, a neopentyl group, or a cyclopentyl group. As the alkyl group, for example, a methyl group or an ethyl group is preferable.

  The polyhydric alcohol in the fatty acid polyhydric alcohol ester may be divalent to hexavalent, for example. Examples of the divalent to hexavalent polyhydric alcohol include glycol (ethylene glycol, propylene glycol, butylene glycol, etc.), glycerol (glycerin), pentaerythritol, or sorbitol.

  Accordingly, the fatty acid ester is not particularly limited. For example, methyl caprylate, methyl caprate, methyl laurate, methyl myristate, methyl palmitate, methyl palmitate, methyl stearate, methyl oleate, methyl linoleate, caprylic acid It may be a fatty acid alkyl ester such as ethyl, ethyl caprate, ethyl laurate, ethyl myristate, ethyl palmitate, ethyl palmitate, ethyl stearate, ethyl oleate, or ethyl linoleate, or ethylene glycol fatty acid Fats such as esters, propylene glycol fatty acid esters, butylene glycol fatty acid esters, glycerin fatty acid esters, pentaerythritol fatty acid esters, or sorbitol fatty acid esters It may be an acid polyhydric alcohol esters. These fatty acid esters may be used alone or as a mixture of two or more, but are preferably used alone from the viewpoint of producing one kind of sucrose fatty acid ester.

  The amount of fatty acid ester used in the step of producing the fatty acid alkali metal salt is not particularly limited, but the fatty acid ester used for producing the fatty acid alkali metal salt is the same as the fatty acid ester used for producing the sucrose fatty acid ester. In the case where sucrose fatty acid ester is produced using a fatty acid ester that has not been reacted in the production of fatty acid alkali metal salt, the conversion rate in the production reaction of fatty acid alkali metal salt is approximately 100%. You may make it the quantity which added the quantity of the fatty acid ester required for the production | generation of a fatty-acid alkali metal salt, and the quantity of the fatty acid ester required for the production | generation of a sucrose fatty acid ester, or more. On the other hand, when adding fatty acid ester later, the usage-amount of fatty acid ester in the process of producing | generating a fatty-acid alkali metal salt may be the same equivalent or more as desired fatty-acid alkali metal salt.

  The alkali metal salt is a salt of an alkali metal such as lithium, sodium, or potassium. The salt may be, for example, a hydroxide, carbonate, bicarbonate, hydride, or alkoxide. The alkali metal salt is not particularly limited, and may be, for example, potassium hydroxide, potassium carbonate, potassium hydrogen carbonate, methoxy potassium (potassium methoxide), sodium hydroxide, sodium carbonate, sodium hydrogen carbonate, or sodium methoxide. . These alkali metal salts may be used alone or in combination. The amount of the alkali metal salt used is preferably an amount that can produce the necessary amount of the fatty acid alkali metal salt in the step of producing the fatty acid ester, for example, even if it is equivalent to the desired fatty acid alkali metal salt. Good. As the alkali metal salt, it is preferable to use potassium hydroxide or sodium hydroxide.

The solvent is not particularly limited as long as it can dissolve the alkali metal salt. For example, it may be at least one solvent selected from alcohol, ketone, and water. Although alcohol is not specifically limited, For example, C1-C5 alcohol may be sufficient. Examples of the alcohol having 1 to 5 carbon atoms include methanol, ethanol, propanol (1-propanol), isopropanol (2-propanol), n-butanol, isobutanol, sec-butanol, tert-butanol, n-amyl alcohol, Mention may be made of sec-amyl alcohol, 3-pentanol, 2-methyl-1-butanol, isoamyl alcohol, tert-amyl alcohol, 3-methyl-2-butanol, or neopentyl alcohol. These alcohols may be used alone or in combination. Examples of the ketone having 3 to 5 carbon atoms include acetone, methyl ethyl ketone, and diethyl ketone. These ketones may be used alone or in combination. The solvent is preferably methanol or ethanol. This is because it is easy to remove later. Further, it is preferable to use the same solvent as that produced by the reaction between the fatty acid ester and the alkali metal salt. For example, when a fatty acid alkyl ester having a methyl group or an ethyl group is reacted with an alkali metal hydroxide, it is preferable to use methanol or ethanol as a solvent. Further, since this solvent does not contribute to the reaction, the amount of use thereof is arbitrary as long as the alkali metal salt is dissolved.
When the alkali metal salt is dissolved in the solvent, stirring may be performed or stirring may not be performed. Further, it may be heated or not heated during the dissolution.

  In the mixed liquid obtained by mixing the fatty acid ester and the alkali metal salt solution, the fatty acid ester is preferably dissolved. In the mixed solution, the fatty acid ester may be melted or dissolved, for example. When the fatty acid ester is solid at room temperature, the fatty acid ester previously melted or dissolved in a solvent may be mixed with the alkali metal salt solution, or the solid fatty acid ester is a solution of the alkali metal salt. It may melt after being mixed with. In the former case, for example, the solid fatty acid ester may be melted by being heated to a melting point or higher, or the solid fatty acid ester is a non-polar solvent such as alcohol, ketone, hexane or heptane. It may be dissolved in an organic solvent. When the solid fatty acid ester is dissolved in the organic solvent, it may be heated or may not be heated. In addition, the heating performed when the solid fatty acid ester is melted or dissolved in a solvent may or may not be performed by microwave irradiation.

  When a fatty acid ester and a solution in which an alkali metal salt is dissolved in a solvent are mixed and heated, a fatty acid alkali metal salt can be generated. Note that microwaves are preferably used for heating, but this need not be the case. It is preferable to perform refluxing during the heating. Although the temperature of heating is not specifically limited, The range of 30 degreeC-200 degreeC is suitable, and 60 degreeC or more is more suitable. The heating time is not particularly limited, but is preferably in the range of 5 minutes to 24 hours, more preferably in the range of 20 minutes to 2 hours, and still more preferably in the range of 30 minutes to 1 hour. Moreover, it is suitable to make it react under reduced pressure. At the start of heating, the pressure may be reduced or normal pressure. When the pressure is normal at the start of heating, the pressure reduction may be started together with the heating. The pressure is preferably reduced to 1 to 90 kPa by decompression, more preferably 1 to 10 kPa, and further preferably 1 to 4 kPa. Examples of the alkali metal of the fatty acid alkali metal salt produced by the reaction are as described above, and examples of the fatty acid are also as described above. Therefore, as the fatty acid alkali metal salt to be produced, for example, potassium caprylate, potassium caprate, potassium laurate, potassium myristate, potassium palmitate, potassium palmitate, potassium stearate, potassium oleate, potassium linoleate, Mention may be made of sodium caprylate, sodium caprate, sodium laurate, sodium myristate, sodium palmitate, sodium palmitate, sodium stearate, sodium oleate or sodium linoleate. Since the fatty acid alkali metal salt produced in this step does not dissolve in the solvent, the fatty acid alkali metal salt can be obtained by removing the solvent. The solvent can be removed, for example, by continuing heating or decompression. The fatty acid alkali metal salt may or may not contain an unreacted fatty acid ester. It is preferable to lower the temperature after the reaction is completed. Although the temperature after the fall is not particularly limited, for example, it is preferably less than 100 ° C. or higher than the melting point of the unreacted fatty acid ester.

  The basic catalyst is not particularly limited as long as it is a basic catalyst, but may be, for example, an alkali metal salt, an alkaline earth metal salt, or a metal salt. The alkali metal salt is a salt of an alkali metal such as lithium, sodium, or potassium. The alkaline earth metal salt is, for example, a salt of an alkaline earth metal such as beryllium, magnesium, or calcium. The metal salt is a salt of a metal such as manganese, zinc, copper, or nickel. The salt may be, for example, a hydroxide, carbonate, bicarbonate, hydride, or alkoxide, as described above. The alkali metal salt is not particularly limited, and may be, for example, potassium hydroxide, potassium carbonate, potassium hydrogen carbonate, methoxy potassium, sodium hydroxide, sodium carbonate, sodium hydrogen carbonate, or sodium methoxide. The alkaline earth metal salt is not particularly limited, and may be, for example, magnesium hydroxide, magnesium carbonate, magnesium hydrogen carbonate, magnesium methoxide, calcium hydroxide, calcium carbonate, calcium hydrogen carbonate, or calcium methoxide. Moreover, although a metal salt is not specifically limited, For example, manganese hydroxide or zinc hydroxide may be sufficient. These basic catalysts may be used alone or as a mixture of two or more. This basic catalyst is at least partially soluble in water. Therefore, this basic catalyst can also be called a water-soluble catalyst. In addition, it is preferable to use a basic catalyst that is completely soluble in water. Moreover, since this basic catalyst is used in esterification of the hydroxyl group of sucrose, it can also be called an esterification catalyst. The basic catalyst is preferably the same alkali metal salt as the alkali metal of the fatty acid alkali metal salt. For example, when the alkali metal of the fatty acid alkali metal salt is potassium or sodium, the basic catalyst is preferably potassium hydroxide or sodium hydroxide.

  In addition, the amount of water in the step of preparing the aqueous solution containing sucrose and the basic catalyst is not limited, but since it is necessary to remove the water later, it is the minimum amount of water in a range where sucrose can be dissolved. Is preferred. In addition, the amount of the basic catalyst is preferably in the range of 0.01 to 20% by weight and more preferably in the range of 0.1 to 5% by weight with respect to sucrose. Moreover, in the process, in order to dissolve sucrose or a basic catalyst in water, for example, stirring such as rotary stirring or rocking stirring may be performed. In the process, heating may be performed or may not be performed. Moreover, the order in which sucrose and a basic catalyst are dissolved in water is not ask | required.

  Examples of the fatty acid ester used in the step of producing the sucrose fatty acid ester are as described above. The fatty acid ester may be the same as or different from the fatty acid ester used in the step of producing the fatty acid alkali metal salt. In the former case, as described above, an unreacted fatty acid ester that was not used in the reaction in the step of producing the fatty acid alkali metal salt may be used in the step of producing the sucrose fatty acid ester, or The same fatty acid ester may be newly added. When a fatty acid ester is newly charged and the fatty acid ester to be charged is solid at room temperature, the fatty acid ester may be melted or charged or melted after being charged. May be. In any case, it is preferred that the fatty acid ester is melted when the sucrose fatty acid ester is produced. If the fatty acid ester used to produce the sucrose fatty acid ester is the same as the fatty acid ester used to produce the fatty acid alkali metal salt, even if an excess amount of fatty acid ester is used relative to sucrose, When the fatty acid ester is recovered and used, there is an advantage that reusability is good because other types of fatty acid esters are not mixed. This fatty acid alkali metal salt is used as an emulsifier in a mixture of an aqueous solution of sucrose and a fatty acid ester.

  Moreover, the illustration of the fatty acid alkali metal salt used in the step of producing the sucrose fatty acid ester is as described above, and these fatty acid alkali metal salts may be used singly or in a plurality of mixtures. May be. The amount of fatty acid alkali metal salt used is not particularly limited. For example, it is preferably 1 to 50% by weight based on the total mixture, and the fatty acid ester used in the production of sucrose fatty acid ester is a fatty acid alkyl ester. In some cases, it is more preferably 10 to 30% by weight.

  In the step of producing sucrose fatty acid ester, an aqueous solution in which sucrose is dissolved in water in the presence of a basic catalyst, the fatty acid alkali metal salt produced in the previous step, and the fatty acid ester are mixed and mixed under reduced pressure. The sucrose fatty acid ester is produced by stirring and heating at As a result of this mixing, the mixing order is not limited as long as the aqueous solution, the fatty acid alkali metal salt, and the fatty acid ester are mixed. In addition, the fatty acid ester should just melt | dissolve after mixing as a result. Therefore, the fatty acid ester may be melted at the time of mixing, or may not be melted at the time of mixing and may be melted after mixing. In the former case, when the fatty acid ester is solid at room temperature, the fatty acid ester may be melted by heating, for example. In addition, it is suitable for this liquid mixture not to contain the organic solvent. In addition, the fatty acid ester mixed with sucrose in this step is preferably in the range of 1 to 20 equivalents per 1 equivalent of sucrose. Thus, the amount of fatty acid ester used is preferably the same or excessive amount as sucrose. The stirring performed in this step may be, for example, rotational stirring, rocking stirring, ultrasonic stirring, or any combination of two or more thereof. The stirring may be performed continuously or intermittently. A mixture obtained by mixing an aqueous solution of sucrose, a fatty acid alkali metal salt, and a fatty acid ester is a fluid having a high viscosity. Therefore, this mixture can also be considered as a highly viscous liquid mixture.

  The step of producing a sucrose fatty acid ester has a preceding step of removing water from the mixture, and a subsequent step of performing transesterification in a state where water is removed after the preceding step. In the preceding step, it is preferable that sufficient stirring is performed in order to remove water in a state where the dispersoid which is an aqueous solution of sucrose is uniformly dispersed. In the subsequent step, it is preferable that sufficient stirring is performed from the viewpoint of promoting transesterification between sucrose and a fatty acid ester.

  The heating in the previous step in the step of producing the sucrose fatty acid ester may or may not be performed by irradiation with microwaves. The heating of the latter process in the process of producing the sucrose fatty acid ester is performed by irradiating with microwaves. The frequency of the microwave is not particularly limited. For example, the frequency may be 2.45 GHz, 5.8 GHz, 24 GHz, 915 MHz, or other 300 MHz to 300 GHz. A frequency within the range may be used. Moreover, the microwave of a single frequency may be irradiated and the microwave of a several frequency may be irradiated. In the latter case, for example, microwaves having a plurality of frequencies may be irradiated at the same time, or may be irradiated at different times. When microwaves with multiple frequencies are irradiated at different times, for example, microwaves with frequencies that are easily absorbed by the raw material are irradiated at the start of the reaction, and the product is absorbed at the time when the reaction proceeds. Microwaves with a frequency that can be easily applied may be irradiated. Further, for example, microwaves having a plurality of frequencies may be irradiated at the same position or may be irradiated at different positions. When microwaves of a plurality of frequencies are respectively irradiated at different positions, for example, at a position on the upstream side of the flow type reactor, that is, at a position where the ratio of the raw material is higher than that of the product, Microwaves may be irradiated, and microwaves having a frequency that is easily absorbed by the product may be irradiated at a position downstream of the reactor, that is, at a position where the ratio of the product is higher than that of the raw material. Further, the microwave irradiation may be performed continuously, or may be performed intermittently between irradiation and pause. Irradiation with microwaves raises the temperature of the object to be irradiated, but the intensity of microwave irradiation may be adjusted so that the temperature remains constant. Well, or the intensity of microwave irradiation may be changed in small increments. The temperature of the mixture to be irradiated with the microwave may be measured using a known thermometer such as a thermocouple thermometer or an infrared optical fiber thermometer. The measured temperature may be used to control the output (intensity) of the microwave. The microwave irradiation may be performed in a single mode or in a multimode. In addition, the catalyst which has a microwave absorptivity may be injected | thrown-in to the mixture which is a microwave irradiation object, and it may not be so. When the produced sucrose fatty acid ester is used for foods and pharmaceuticals and the catalyst needs to be completely removed after the reaction, it is preferable not to use the catalyst.

  The temperature of the preceding step, that is, the step of removing water from the mixture, is preferably lower than the reaction temperature of the subsequent step, that is, the step of transesterification. If the temperature in the previous step is the same as or higher than the reaction temperature in the subsequent transesterification step, the transesterification starts in the previous step, resulting in a low yield of sucrose fatty acid ester in the subsequent step. Because it becomes. On the other hand, if the temperature of the preceding step is too low, water cannot be removed, and the reaction in the subsequent step is hindered. Therefore, it is preferable that the temperature of the mixture in the preceding step is higher than room temperature and lower than the reaction temperature in the subsequent step. For example, in the preceding step, it is preferably heated in the range of 40 ° C to 80 ° C, and more preferably in the range of 50 ° C to 80 ° C. Further, the time of the previous step is preferably in the range of 5 minutes to 24 hours, more preferably in the range of 20 minutes to 2 hours, and in the range of 30 minutes to 1 hour. Is more preferred. The removal of water is preferably performed until the amount of remaining water is 0.1 to 2% by weight based on the entire mixture.

  In the subsequent step, the mixture is heated so as to be lower than the decomposition temperature of sucrose. This is because when heated above the decomposition temperature of sucrose, an odor (so-called caramel odor) is generated, and the quality of the sucrose fatty acid ester deteriorates. The sucrose decomposition temperature is a temperature at which sucrose decomposition begins. The decomposition temperature at which sucrose odors when heated for a short time begins around 135 ° C. In the subsequent step, for example, it is preferable that the heating is performed in a range lower than the decomposition temperature of sucrose by 25 ° C. to a range lower than the decomposition temperature of sucrose, and a temperature lower by 10 ° C. than the decomposition temperature of sucrose. Therefore, it is more preferable to heat to a range below the decomposition temperature of sucrose. This is because a higher monoester yield can be realized in a shorter time when the reaction temperature in the subsequent step is closer to the decomposition temperature of sucrose. In the subsequent step, the mixture is preferably heated to a range of 100 ° C to 135 ° C, more preferably heated to a range of 110 ° C to 133 ° C, and in a range of 110 ° C to 130 ° C. More preferably it is heated. In the subsequent step, the mixture may be heated to 120 ° C. or higher. In the subsequent step, heating by microwaves may be performed so that the measurement temperature of the mixture becomes “decomposition temperature of sucrose−α (° C.)”. α is a positive real number. Note that α is preferably a small value, but the value of α may be selected in accordance with the responsiveness of feedback of temperature control using microwaves. Specifically, the value of α may be decreased when the responsiveness is high, and the value of α may be increased when the responsiveness is low. The reaction time (heating time) in the subsequent step is preferably 5 minutes to 6 hours. In addition, the minimum of the reaction time may be 30 minutes or more, for example, and may be 1 hour or more. Further, the upper limit of the reaction time may be, for example, 6 hours or less, 5 hours or less, 4 hours or less, 3.5 hours or less, 3 It may be less than time. From the viewpoint of lowering the monoester selectivity, the shorter the time for the subsequent step, the better the time for the subsequent step. On the other hand, from the viewpoint of realizing a high yield of the monoester, it is preferable that the time of the subsequent step is about the time when the yield of the monoester reaches a peak. The temperature may be constant or may vary. In the latter case, for example, the mixture may be heated so as to increase the temperature in the subsequent step of performing the transesterification. The temperature increase may be performed, for example, by a linear temperature change, may be performed by a step-like temperature change, or may be another temperature increase. In addition, when the mixture is heated so that the temperature of the mixture is raised in the subsequent stage, it is preferable that the temperature increases monotonously in the subsequent stage, but as the entire period of the subsequent stage It is sufficient that the temperature rises, and there may be a period during which the temperature falls microscopically. This is because, for example, such a situation can occur when the microwave is intermittently irradiated. In addition, even when the temperature changes in the subsequent steps, it is important that the temperature does not exceed the decomposition temperature of sucrose. In addition, in the produced | generated sucrose fatty acid ester, it is suitable that there is much content rate of a monoester. For example, in the produced sucrose fatty acid ester, the weight ratio of the monoester is preferably larger than the weight ratio of the sucrose fatty acid ester in which two or more hydroxyl groups of sucrose are esterified with the fatty acid ester. Further, for example, in the produced sucrose fatty acid ester, the weight ratio of the monoester is preferably 60% by weight or more, more preferably 70% by weight or more, and 80% by weight or more. More preferably it is. Monoesters of sucrose fatty acid esters are known to have antibacterial properties, and those with a higher monoester content are more soluble in water, so sucrose fatty acid esters are used, for example, in foods and beverages. This is because, in some cases, a high monoester content is required. In addition, high-purity monoesters may be required for uses such as pharmaceuticals. In such cases, it is better to purify high-purity monoesters from those with a high monoester content. In the produced sucrose fatty acid ester, it is preferable that the proportion of monoester is high. As will be described in the examples described later, for example, when the reaction temperature in the subsequent step when producing sucrose palmitate is 120 ° C., the heating time is preferably 3 hours or less. More preferably, it is 2.5 hours or less. In addition, for example, when the reaction temperature in the subsequent step in producing sucrose stearate is 130 ° C., the heating time is preferably 4 hours or less, and 3.5 hours or less. Is more preferred. Moreover, it is suitable that the yield of the monoester of the produced | generated sucrose fatty acid ester is high. In the present invention, such high monoester selectivity and high yield could be achieved by microwave heating.

  The pressure in the front stage and the rear stage is preferably 1 to 90 kPa, and more preferably 1 to 10 kPa. The pressure may be the same in the preceding process and the subsequent process, or may vary. In the latter case, for example, the pressure in the subsequent process may be higher than the pressure in the previous process. Note that the degree of decompression may be within a range in which the raw material (for example, fatty acid ester or the like) does not vaporize.

  The sucrose fatty acid ester is produced by transesterification in the step of producing the sucrose fatty acid ester. The sucrose fatty acid ester is not particularly limited. For example, sucrose caprylate, sucrose caprate, sucrose laurate, sucrose myristate, sucrose myristoleate, sucrose palmitate, sucrose Sugar palmitoleate, sucrose stearate, sucrose oleate, sucrose linoleate, sucrose linolenate, sucrose eleostearate, sucrose arachidate, sucrose mead, sucrose It may be sugar arachidonic acid ester, sucrose behenic acid ester, sucrose lignoceric acid ester, sucrose nervonic acid ester, sucrose erucic acid ester or the like. In the subsequent step of producing a sucrose fatty acid ester, the mixture may be cooled after transesterification. This is to prevent the monoester from becoming a diester.

  In addition, as a method of extracting the produced | generated sucrose fatty acid ester, a normal method can be used. For example, when water and an organic solvent (for example, methyl ethyl ketone, water-insoluble alcohol, etc.) are added to the product in the step of producing a sucrose fatty acid ester and stirred, the water layer and the organic solvent layer are separated into two layers. . The organic solvent includes unreacted fatty acid ester and sucrose fatty acid ester. Further, the water contains unreacted sucrose and fatty acid alkali metal salts. The sucrose fatty acid ester can be extracted by crystallizing and extracting the sucrose fatty acid ester from the organic solvent.

  As described above, according to the method for producing a sucrose fatty acid ester according to the present invention, in the subsequent step in the step of producing the sucrose fatty acid ester, by heating the mixture to be lower than the decomposition temperature of sucrose, A sucrose fatty acid ester having no odor can be produced. Further, by heating with microwaves, it becomes possible to obtain a sucrose fatty acid ester having a high monoester selectivity and high yield in a short time. In addition, since no harmful organic solvent is used in the step of producing a sucrose fatty acid ester, a sucrose fatty acid ester suitable for foods, pharmaceuticals, and cosmetics can be produced.

  In addition, in the said description, although the manufacturing method of sucrose fatty acid ester demonstrated the case where the process of producing | generating a fatty-acid alkali metal salt was provided, it may not be so. When a fatty acid alkali metal salt is prepared in advance, the fatty acid alkali metal salt may be used in the step of producing a sucrose fatty acid ester. The fatty acid alkali metal salt may be produced by a method different from the above description.

[Examples, Reference Examples, Comparative Examples]
EXAMPLES Hereinafter, although this invention is demonstrated in detail based on an Example, these Examples are illustrative and this invention is not limited by these Examples.

1. Method for producing sucrose palmitate [Reference Example 1]
A three-necked flask was charged with 98 g of methyl palmitate heated to 60 ° C. and melted and a solution of 3.8 g of potassium hydroxide dissolved in 30 ml of methanol. After placing the three-necked flask in a microwave reactor (μReactor EX, manufactured by Shikoku Keikaku Kogyo Co., Ltd.) equipped with a stirrer and a thermometer, the microwave was irradiated with 2.45 GHz microwave and heated to 100 ° C. while stirring. Reflux was performed for a minute. Thereafter, the temperature was maintained at 100 ° C. while reducing the pressure to 4 kPa, thereby producing potassium palmitate. Moreover, after maintaining this state and removing methanol sufficiently, the contents were cooled to 60 ° C. The contents are a mixture of 80 g of methyl palmitate and 20 g of potassium palmitate. An aqueous solution in which 12 g of sucrose and 0.5 g of potassium hydroxide were dissolved in 12 g of water was charged into the three-necked flask. While stirring the mixture in the three-necked flask at 60 ° C., the pressure was reduced and the pressure was reduced to 4 kPa. This state was maintained for 30 minutes to evaporate water. Thereafter, microwave irradiation was performed while maintaining stirring and the degree of vacuum, and the temperature was raised to 120 ° C., and a transesterification reaction was performed for 1 hour to produce sucrose palmitate. There was no coloring or odor from the start of the reaction to the end of the reaction. Therefore, the reaction could be performed at a temperature lower than the decomposition start temperature of sucrose. After completion of the reaction, sucrose palmitate was obtained from the reaction product using acetone. The yield of sucrose palmitate and the proportion of monoester were analyzed by high performance liquid chromatography and gas chromatography. The result is as shown in FIG.

[Reference Example 2]
Sucrose palmitate was produced in the same manner as in Reference Example 1 except that the time for transesterification was changed from 1 hour to 2 hours. Also in this case, there was no coloring or odor from the start of the reaction to the end of the reaction. The results are as shown in FIG.

[Reference Example 3]
Sucrose palmitate was produced in the same manner as in Reference Example 1, except that the transesterification time was changed from 1 hour to 3 hours. Also in this case, there was no coloring or odor from the start of the reaction to the end of the reaction. The results are as shown in FIG.

[Reference Example 4]
Sucrose palmitate was produced in the same manner as in Reference Example 2 except that the temperature during the transesterification reaction was changed from 120 ° C to 110 ° C. Also in this case, there was no coloring or odor from the start of the reaction to the end of the reaction. The results are as shown in FIG.

[Reference Example 5]
Sucrose palmitate was produced in the same manner as in Reference Example 4 except that the transesterification time was changed from 2 hours to 4 hours. Also in this case, there was no coloring or odor from the start of the reaction to the end of the reaction. The results are as shown in FIG.

[Reference Example 6]
Sucrose palmitate was produced in the same manner as in Reference Example 2 except that the temperature during the transesterification reaction was changed from 120 ° C to 100 ° C. Also in this case, there was no coloring or odor from the start of the reaction to the end of the reaction. The results are as shown in FIG.

[Reference Example 7]
The temperature of the transesterification reaction was set to 110 ° C. for the first half hour and 120 ° C. for the first half hour, and the transesterification reaction was performed for a total of 2 hours. Generated. In addition, the temperature increase from 110 ° C. to 120 ° C. was performed immediately, and the degree of vacuum was maintained at that time. Also in this case, there was no coloring or odor from the start of the reaction to the end of the reaction. The results are as shown in FIG.

[Comparative Example 1]
Sucrose palmitate was produced in the same manner as in Reference Example 2 except that heating by microwave irradiation was changed to heating by an oil bath (conventional heating). In this case, the reaction solution colored brownish brown during the transesterification reaction and had a burnt sucrose smell. The results are as shown in FIG.
Even when the temperature during the transesterification reaction was changed from 120 ° C. to 110 ° C., the reaction solution was colored brown as in Comparative Example 1.

[Comparative Example 2]
Production of sucrose palmitate was carried out in the same manner as in Comparative Example 1 except that the temperature during the transesterification reaction was changed from 120 ° C. to 100 ° C. and the time for the transesterification reaction was changed from 2 hours to 1 hour. It was. In this case, there was no coloring or odor from the start of the reaction to the end of the reaction. The results are as shown in FIG.

[Comparative Example 3]
Sucrose palmitate was produced in the same manner as in Comparative Example 2 except that the time for transesterification was changed from 1 hour to 2 hours. Also in this case, there was no coloring or odor from the start of the reaction to the end of the reaction. The results are as shown in FIG.

[Comparative Example 4]
Sucrose palmitate was produced in the same manner as in Comparative Example 2 except that the time for the transesterification reaction was changed from 1 hour to 4 hours. Also in this case, there was no coloring or odor from the start of the reaction to the end of the reaction. The results are as shown in FIG.

  In conventional heating, the temperature must be lowered in order to prevent coloring or odor generation. Further, when the sucrose fatty acid ester is produced by lowering the temperature in the conventional heating, as can be seen from the results of Comparative Examples 2 to 4, when the yield of the monoester increases, the weight ratio of the monoester decreases. Thus, when the weight ratio of the monoester increases, the yield of the monoester decreases. On the other hand, in the case of the reference examples 1-7 which performed microwave heating, compared with the comparative examples 2-4, the high yield of a monoester and the high weight ratio can be made compatible. In particular, the yield is 1.5 times or more that of Comparative Examples 2 to 4 although the weight ratio of the monoester is 70% by weight or more. In Reference Example 2, such a high yield and high weight ratio of the monoester can be realized in a short time.

  FIG. 2 is a graph showing the change over time in the yield of monoester and the weight ratio of monoester in Reference Examples 1 to 3 and Comparative Examples 2 to 4. In the production of sucrose fatty acid ester, first, a monoester is produced, a diester is produced from the monoester, and a triester is produced from the diester. As shown by the change in the yield, the yield of the monoester gradually increases with the passage of time and starts to decrease from the middle. Moreover, since the diester etc. are produced | generated with progress of time, the ratio of a monoester will fall gradually from 100%.

  In FIG. 2, the time change of the yield of the monoester in microwave heating (MW) is shortened by less than 1/2 with respect to the time change of the yield of monoester in the conventional heating (CH). I understand that. This is because, assuming that the change in yield up to 4 hours of conventional heating is monotonically increasing, for example, the time of microwave heating corresponding to the yield of 2 hours of conventional heating is shorter than 1 hour, which is 4 times higher than that of conventional heating. This is because the microwave heating time corresponding to the time yield is also shorter than 2 hours. On the other hand, it can be seen that the time change of the monoester ratio in the microwave heating is not shortened to 1/2 with respect to the time change of the monoester ratio in the conventional heating. This is because the weight ratio (83%) of the monoester of Comparative Example 3 is smaller than the weight ratio (85%) of the monoester of Reference Example 1. In this way, in the reaction of sequentially esterifying a plurality of hydroxyl groups of sucrose, when the conventional heating is changed to microwave heating, the yield of the monoester is more in the time direction than the proportion of the monoester. It can be seen that is shortened shorter. Due to the existence of such differences, microwave heating can simultaneously achieve a high yield of monoester and a high selectivity in a short reaction time range (for example, a reaction time within 4 hours). become.

  Further, as shown in Reference Example 7, it can be seen that a higher yield of monoester and a higher selectivity of monoester can be achieved by increasing the reaction temperature stepwise during the transesterification reaction. Therefore, it is considered that a higher yield of monoester and a higher selectivity of monoester can be compatible by heating the mixture so that the temperature of the mixture is increased during the transesterification reaction.

  In addition, if FIG. 2 is referred, it turns out that the yield of the monoester in 120 degreeC microwave heating (Reference Examples 1-3) has a peak in the heating time of 2 hours vicinity. Therefore, the time for the transesterification reaction (that is, the heating time in the subsequent step) may be the time for which the yield of the monoester reaches a peak. Here, the time when the yield of the monoester reaches a peak should theoretically be one point in time, but in reality, it is difficult to specify the point. Therefore, the time when the yield of the monoester reaches a peak may be considered as a period having a width. For example, the time for the transesterification reaction in which the yield of monoester reaches a peak in microwave heating at 120 ° C. (Reference Examples 1 to 3) may be considered to be in the range of 1.5 hours to 2.5 hours. Good.

  Further, by comparing the results of Reference Examples 2, 4, and 6, it can be seen that the higher the reaction temperature, the higher the yield of the monoester can be realized in the range below the decomposition temperature of sucrose. Therefore, it can be seen that the reaction is preferably performed at a reaction temperature closer to the decomposition temperature of sucrose.

2. Method for producing sucrose stearate [Reference Example 8]
In a three-necked flask, 108.6 g of methyl stearate heated to 60 ° C. and melted and a solution prepared by dissolving 3.8 g of potassium hydroxide in 30 ml of methanol were added. After placing the three-necked flask in a microwave reactor (μReactor EX, manufactured by Shikoku Keikaku Kogyo Co., Ltd.) equipped with a stirrer and a thermometer, the microwave was irradiated with 2.45 GHz microwave and heated to 100 ° C. while stirring. Reflux was performed for a minute. Thereafter, the temperature was maintained at 100 ° C. while reducing the pressure to 4 kPa, thereby producing potassium stearate. Moreover, after maintaining this state and removing methanol sufficiently, the content was cooled to 80 degreeC. The content is a mixture of 88.3 g methyl stearate and 21.9 g potassium stearate. An aqueous solution in which 12 g of sucrose and 0.5 g of potassium hydroxide were dissolved in 8 g of water was charged into the three-necked flask. While stirring the mixture in the three-necked flask, the pressure was reduced while stirring, and the pressure was reduced to 4 kPa to evaporate water. Thereafter, microwave irradiation was performed while maintaining stirring and the degree of vacuum, and the temperature was raised to 130 ° C., and a transesterification reaction was performed for 1 hour to produce sucrose stearate. There was no odor from the start of the reaction to the end of the reaction. Therefore, the reaction could be performed at a temperature lower than the decomposition start temperature of sucrose. After completion of the reaction, sucrose stearate was obtained from the reaction product using acetone. The yield of sucrose stearate and the proportion of monoester were analyzed by high performance liquid chromatography and gas chromatography. The result is as shown in FIG.

[Reference Example 9]
Sucrose stearate was produced in the same manner as in Reference Example 8 except that the time for transesterification was changed from 1 hour to 2 hours. Also in this case, there was no odor from the start of the reaction to the end of the reaction. The results are as shown in FIG.

[Reference Example 10]
Sucrose stearate was produced in the same manner as in Reference Example 8 except that the time for transesterification was changed from 1 hour to 3 hours. Also in this case, there was no odor from the start of the reaction to the end of the reaction. The results are as shown in FIG.

[Reference Example 11]
Sucrose stearate was produced in the same manner as in Reference Example 8 except that the time for transesterification was changed from 1 hour to 4 hours. Also in this case, there was no odor from the start of the reaction to the end of the reaction. The results are as shown in FIG.

[Reference Example 12]
Sucrose stearate was produced in the same manner as in Reference Example 8 except that the temperature during the transesterification reaction was changed from 130 ° C to 120 ° C. Also in this case, there was no odor from the start of the reaction to the end of the reaction. The results are as shown in FIG.

[Reference Example 13]
Sucrose stearate was produced in the same manner as in Reference Example 12 except that the time for transesterification was changed from 1 hour to 2 hours. Also in this case, there was no odor from the start of the reaction to the end of the reaction. The results are as shown in FIG.

[Reference Example 14]
Sucrose stearate was produced in the same manner as in Reference Example 12 except that the time for transesterification was changed from 1 hour to 3 hours. Also in this case, there was no odor from the start of the reaction to the end of the reaction. The results are as shown in FIG.

[Reference Example 15]
Sucrose stearate was produced in the same manner as in Reference Example 12 except that the time for transesterification was changed from 1 hour to 4 hours. Also in this case, there was no odor from the start of the reaction to the end of the reaction. The results are as shown in FIG.

[Comparative Example 5]
Sucrose stearate in the same manner as in Reference Example 11 except that the heating by microwave irradiation was changed to heating by an oil bath (conventional heating) and the temperature during the transesterification reaction was changed from 130 ° C to 110 ° C. Was generated. In this case, the sucrose burnt in the reaction solution during the transesterification reaction. The results are as shown in FIG.
In addition, in the heating with an oil bath, when the temperature during the transesterification reaction was set to 130 ° C. or 120 ° C., the reaction solution was burnt black and the burnt sucrose smell. Therefore, when heating to 110 ° C. or higher in conventional heating, it is difficult to produce sucrose stearate without odor.

[Comparative Example 6]
Production of sucrose stearate was carried out in the same manner as in Comparative Example 5, except that the temperature during the transesterification reaction was changed from 110 ° C. to 100 ° C., and the transesterification time was changed from 4 hours to 1 hour. It was. In this case, there was no odor from the start of the reaction to the end of the reaction. The results are as shown in FIG.

[Comparative Example 7]
Sucrose stearate was produced in the same manner as in Comparative Example 6 except that the time for the transesterification reaction was changed from 1 hour to 2 hours. Also in this case, there was no odor from the start of the reaction to the end of the reaction. The results are as shown in FIG.

[Comparative Example 8]
Sucrose stearate was produced in the same manner as in Comparative Example 6 except that the time for transesterification was changed from 1 hour to 3 hours. Also in this case, there was no odor from the start of the reaction to the end of the reaction. The results are as shown in FIG.

[Comparative Example 9]
Sucrose stearate was produced in the same manner as in Comparative Example 6 except that the time for the transesterification reaction was changed from 1 hour to 4 hours. Also in this case, there was no odor from the start of the reaction to the end of the reaction. The results are as shown in FIG.

[Comparative Example 10]
Sucrose stearate was produced in the same manner as in Comparative Example 6 except that the time for the transesterification reaction was changed from 1 hour to 6 hours. In this case, the sucrose burnt in the reaction solution during the transesterification reaction. The results are as shown in FIG.

  In conventional heating, the temperature must be lowered to prevent odors from occurring. In addition, when the production of sucrose stearate is performed by lowering the temperature in conventional heating, as can be seen from the results of Comparative Examples 6 to 10, when the yield of monoester increases, the weight ratio of monoester increases. The lower the monoester yield, the lower the monoester yield. On the other hand, in the case of the reference examples 8-15 which performed microwave heating, compared with the comparative examples 6-9, the high yield of a monoester and the high weight ratio can be made compatible. For example, comparing the yield of monoesters in Reference Example 10 and Comparative Example 10 in which the weight ratio of monoesters is comparable, microwave heating can achieve a yield about 1.7 times that of conventional heating. Yes. In microwave heating, such a high yield can be realized without causing odor. In addition, in the conventional heating, the time change of the yield of the monoester is gradual, and the odor is generated when the heating is performed for a long time (for example, see Comparative Example 10). As a result, the high yield of the monoester is obtained. Although the rate cannot be realized, the reference examples 10, 11, 15 and the like can achieve a higher yield than the comparative example. Particularly in Reference Example 10, a high yield and a high weight ratio of the monoester can be realized in a short time.

  FIG. 4 is a graph showing the change over time in the yield of monoesters in Reference Examples 8 to 15 and Comparative Examples 6 to 9 and the weight ratio of monoesters. In the production of sucrose stearate, the reaction proceeds such that a monoester is first produced, a diester is produced from the monoester, and a triester is produced from the diester. As shown by the change in the yield of 11, the yield of the monoester gradually increases with the passage of time and starts to decrease from the middle. Moreover, since the diester etc. are produced | generated with progress of time, the ratio of a monoester will fall gradually from 100%.

  In FIG. 4, for example, when the microwave heating at 130 ° C. (Reference Examples 8 to 11) and the conventional heating at 100 ° C. (Comparative Examples 6 to 9) are compared, the time change of the yield of monoester in the microwave heating It can be seen that the time is shortened to less than 1/4 with respect to the time change of the yield of the monoester in the conventional heating. This is because, assuming that the change in yield up to 4 hours of conventional heating is monotonically increasing, the time of microwave heating corresponding to the yield of 4 hours of conventional heating is shorter than 1 hour. On the other hand, it can be seen that the time change of the monoester ratio in the microwave heating is not shortened to ¼ the time change of the monoester ratio in the conventional heating. This is because the weight ratio (88.9%) of the monoester of Comparative Example 9 is smaller than the weight ratio (90.7%) of the monoester of Reference Example 8. In this way, in the reaction of sequentially esterifying a plurality of hydroxyl groups of sucrose, when the conventional heating is changed to microwave heating, the yield of the monoester is more in the time direction than the proportion of the monoester. It can be seen that is shortened shorter. Due to the existence of such differences, microwave heating can simultaneously achieve a high yield of monoester and a high selectivity in a short reaction time range (for example, a reaction time within 4 hours). become.

  In addition, if FIG. 4 is referred, it turns out that the yield of the monoester in 130 degreeC microwave heating (Reference Examples 8-11) has a peak in the heating time of about 3 hours. Therefore, the time for the transesterification reaction (that is, the heating time in the subsequent step) may be the time for which the yield of the monoester reaches a peak. Here, the time when the yield of the monoester reaches a peak should theoretically be one point in time, but in reality, it is difficult to specify the point. Therefore, the time when the yield of the monoester reaches a peak may be considered as a period having a width. For example, the time for the transesterification reaction in which the yield of monoester peaks in microwave heating at 130 ° C. (Reference Examples 8 to 11) may be considered to be in the range of 2.5 hours to 3.5 hours. Good.

  Further, by comparing Reference Examples 8 to 11 and Reference Examples 12 to 15, it can be seen that the higher the reaction temperature, the higher the yield of monoester can be realized in the range below the decomposition temperature of sucrose. . Therefore, it can be seen that the reaction is preferably performed at a reaction temperature closer to the decomposition temperature of sucrose.

  Here, Reference Examples 1 to 15 are reference examples by excluding palmitic acid esters and stearic acid esters from constituent fatty acids of fatty acid esters in the claims, and there is no exclusion thereof. In this case, Examples 1 to 15 are used.

3. Method for producing sucrose caprylate [Example 16]
A three-necked flask was charged with 57.5 g of methyl caprylate heated to 60 ° C. and melted and a solution of 3.8 g of potassium hydroxide dissolved in 30 ml of methanol. After placing the three-necked flask in a microwave reactor (μReactor EX, manufactured by Shikoku Keikaku Kogyo Co., Ltd.) equipped with a stirrer and a thermometer, the microwave was irradiated with 2.45 GHz microwave and heated to 100 ° C. while stirring. Reflux was performed for a minute. Thereafter, the temperature was maintained at 100 ° C. while reducing the pressure to 10 kPa, thereby generating potassium caprylate. Moreover, after maintaining this state and removing methanol sufficiently, the content was cooled to 80 degreeC. The content is a mixture of 46.8 g methyl caprylate and 12.3 g potassium caprylate. An aqueous solution in which 12 g of sucrose and 0.5 g of potassium hydroxide were dissolved in 8 g of water was charged into the three-necked flask. While stirring the mixture in the three-necked flask at 80 ° C., the pressure was reduced and the pressure was reduced to 10 kPa to evaporate water. Thereafter, microwave irradiation was performed while maintaining stirring and the degree of vacuum, and the temperature was raised to 130 ° C., and a transesterification reaction was performed for 1 hour to produce sucrose caprylate. There was no odor from the start of the reaction to the end of the reaction. Therefore, the reaction could be performed at a temperature lower than the decomposition start temperature of sucrose. After completion of the reaction, sucrose caprylate was obtained from the reaction product using acetone. The yield of sucrose caprylate and the proportion of monoester were analyzed by high performance liquid chromatography and gas chromatography. The result is as shown in FIG.

[Examples 17 to 20]
Sucrose caprylate was produced in the same manner as in Example 16 except that the time for transesterification was changed from 1 hour to 2 hours, 3 hours, 4 hours, and 6 hours. Also in this case, there was no odor from the start of the reaction to the end of the reaction. The results are as shown in FIG.

[Examples 21 to 25]
Sucrose caprylate was produced in the same manner as in Examples 16 to 20, except that the temperature during the transesterification reaction was changed from 130 ° C to 120 ° C. Also in this case, there was no odor from the start of the reaction to the end of the reaction. The results are as shown in FIG.

[Examples 26 to 30]
Sucrose caprylate was produced in the same manner as in Examples 16 to 20, except that the temperature during the transesterification reaction was changed from 130 ° C to 110 ° C. Also in this case, there was no odor from the start of the reaction to the end of the reaction. The results are as shown in FIG.

[Comparative Examples 11-15]
Sucrose caprylate was produced in the same manner as in Examples 26 to 30 except that heating by microwave irradiation was changed to heating by an oil bath (conventional heating). In this case, there was no odor from the start of the reaction to the end of the reaction. The results are as shown in FIG.

  In addition, in the heating with an oil bath, when the temperature during the transesterification reaction was set to 130 ° C., the reaction liquid was burnt black and the sucrose was burnt. In addition, when the temperature during the transesterification reaction was set to 120 ° C. in the heating with the oil bath, the reaction solution was scorched black and the sucrose was smelled by heating for 2 hours. Therefore, it is difficult to produce a sucrose caprylate without odor when heated to 120 ° C. or higher in conventional heating.

[Comparative Examples 16 to 20]
Sucrose caprylate was produced in the same manner as in Comparative Examples 11 to 15 except that the temperature during the transesterification reaction was changed from 110 ° C to 100 ° C. Also in this case, there was no odor from the start of the reaction to the end of the reaction. The results are as shown in FIG.

  In conventional heating, the temperature must be lowered to prevent odors from occurring. In addition, when the production of sucrose caprylate is carried out by lowering the temperature in conventional heating, as can be seen from the results of Comparative Examples 11 to 20, when the yield of monoester increases, the weight ratio of monoester increases. The lower the monoester yield, the lower the monoester yield. On the other hand, in the case of Examples 16-30 which performed microwave heating, compared with Comparative Examples 11-20, the high yield of a monoester and the high weight ratio can be made compatible. For example, for all of Examples 16-30, microwave heating can achieve a higher yield than conventional heating, whereas in conventional heating, the time change in the yield of monoester is gradual, As a result, high yields of monoesters cannot be realized. In microwave heating, such a high yield can be realized without causing odor. Moreover, in Examples 17 and 22, a high yield and a high weight ratio of the monoester can be realized in a short time.

  FIG. 6 is a graph showing the change over time in the yield of monoesters in Examples 16-30 and Comparative Examples 11-20 and the weight ratio of monoesters. In the production of sucrose caprylate, first, a monoester is produced, a diester is produced from the monoester, and a triester is produced from the diester. As shown by the change in the yield of 30, the yield of the monoester gradually increases with the passage of time and starts to decrease from the middle. Moreover, since the diester etc. are produced | generated with progress of time, the ratio of a monoester will fall gradually from 100%.

  In FIG. 6, for example, when the microwave heating at 130 ° C. (Examples 16 to 20) and the conventional heating at 110 ° C. (Comparative Examples 11 to 15) are compared, the time change of the yield of monoester in the microwave heating It can be seen that the time is shortened to less than 1/8 with respect to the time change of the yield of monoester in the conventional heating. Because it is assumed that both the change in yield up to 1 hour of microwave heating and the change in yield up to 4 hours of conventional heating are monotonically increasing, the micro- This is because the wave heating time is shorter than 0.5 hours. On the other hand, it can be seen that the time change of the monoester ratio in the microwave heating is not shortened to 1/8 with respect to the time change of the monoester ratio in the conventional heating. This is because the weight ratio (92.5%) of the monoester of Comparative Example 15 is smaller than the weight ratio (99.9%) of the monoester of Example 16. In this way, in the reaction of sequentially esterifying a plurality of hydroxyl groups of sucrose, when the conventional heating is changed to microwave heating, the yield of the monoester is more in the time direction than the proportion of the monoester. It can be seen that is shortened shorter. Due to the existence of such differences, microwave heating can simultaneously achieve a high yield of monoester and high selectivity in a short reaction time range (for example, a reaction time range of 6 hours or less). become.

  In addition, if FIG. 6 is referred, it turns out that the yield of the monoester in 130 degreeC microwave heating (Examples 16-20) has a peak in the heating time of 2 hours vicinity. Therefore, the time for the transesterification reaction (that is, the heating time in the subsequent step) may be the time for which the yield of the monoester reaches a peak. Here, the time when the yield of the monoester reaches a peak should theoretically be one point in time, but in reality, it is difficult to specify the point. Therefore, the time when the yield of the monoester reaches a peak may be considered as a period having a width. For example, the time for the transesterification reaction in which the yield of monoester reaches a peak in microwave heating at 130 ° C. may be considered to be in the range of 1.5 hours to 2.5 hours.

  Moreover, by comparing Examples 16 to 20 with Examples 21 to 25, it can be seen that the higher the reaction temperature, the higher the yield of the monoester can be realized in the range below the decomposition temperature of sucrose. . Therefore, it is considered that the reaction is preferably performed at a reaction temperature closer to the decomposition temperature of sucrose. Further, in this example, when the heating time in the subsequent step is 6 hours or less, a monoester weight ratio of 70% by weight or more can be realized. In particular, when the heating time in the subsequent step is 4 hours or less, a weight ratio of the monoester of 80% by weight or more can be realized.

4). Method for producing sucrose laurate [Example 31]
A three-necked flask was charged with 77.9 g of methyl laurate heated to 60 ° C. and melted, and a solution of 3.8 g of potassium hydroxide dissolved in 30 ml of methanol. After placing the three-necked flask in a microwave reactor (μReactor EX, manufactured by Shikoku Keikaku Kogyo Co., Ltd.) equipped with a stirrer and a thermometer, the microwave was irradiated with 2.45 GHz microwave and heated to 100 ° C. while stirring. Reflux was performed for a minute. Thereafter, the temperature was maintained at 100 ° C. while reducing the pressure to 4 kPa, thereby generating potassium laurate. Moreover, after maintaining this state and removing methanol sufficiently, the content was cooled to 80 degreeC. The contents are a mixture of 63.4 g of methyl laurate and 16.1 g of potassium laurate. An aqueous solution in which 12 g of sucrose and 0.5 g of potassium hydroxide were dissolved in 8 g of water was charged into the three-necked flask. While stirring the mixture in the three-necked flask, the pressure was reduced while stirring, and the pressure was reduced to 4 kPa to evaporate water. Thereafter, microwave irradiation was performed while maintaining stirring and the degree of vacuum, and the temperature was raised to 130 ° C., and a transesterification reaction was performed for 1 hour to produce sucrose laurate. There was no odor from the start of the reaction to the end of the reaction. Therefore, the reaction could be performed at a temperature lower than the decomposition start temperature of sucrose. After completion of the reaction, sucrose laurate was obtained from the reaction product using acetone. The yield of sucrose laurate and the proportion of monoester were analyzed by high performance liquid chromatography and gas chromatography. The result is as shown in FIG.

[Examples 32-35]
Sucrose laurate was produced in the same manner as in Example 31, except that the time for the transesterification reaction was changed from 1 hour to 2 hours, 3 hours, 4 hours, and 6 hours. Also in this case, there was no odor from the start of the reaction to the end of the reaction. The result is as shown in FIG.

[Examples 36 to 40]
Sucrose laurate was produced in the same manner as in Examples 31 to 35 except that the temperature during the transesterification reaction was changed from 130 ° C to 120 ° C. Also in this case, there was no odor from the start of the reaction to the end of the reaction. The result is as shown in FIG.

[Examples 41 to 45]
Sucrose laurate was produced in the same manner as in Examples 31 to 35 except that the temperature during the transesterification reaction was changed from 130 ° C to 110 ° C. Also in this case, there was no odor from the start of the reaction to the end of the reaction. The result is as shown in FIG.

[Comparative Examples 21 to 25]
Sucrose laurate was produced in the same manner as in Examples 41 to 45 except that heating by microwave irradiation was changed to heating by an oil bath (conventional heating). In this case, there was no odor from the start of the reaction to the end of the reaction. The result is as shown in FIG.

  In addition, in the heating with an oil bath, when the temperature during the transesterification reaction was set to 130 ° C., the reaction liquid was burnt black and the sucrose was burnt. In addition, in the heating with an oil bath, when the temperature during the transesterification reaction was set to 120 ° C., the reaction solution had a burnt smell of sucrose by heating for 1 hour. Therefore, when heating to 120 ° C. or higher in conventional heating, it is difficult to produce sucrose laurate without odor.

[Comparative Examples 26-30]
Sucrose laurate was produced in the same manner as in Comparative Examples 21 to 25 except that the temperature during the transesterification reaction was changed from 110 ° C to 100 ° C. Also in this case, there was no odor from the start of the reaction to the end of the reaction. The result is as shown in FIG.

  In conventional heating, the temperature must be lowered to prevent odors from occurring. In addition, when the sucrose laurate is produced by lowering the temperature in the conventional heating, as can be seen from the results of Comparative Examples 21 to 30, when the yield of the monoester increases, the weight ratio of the monoester increases. The lower the monoester yield, the lower the monoester yield. On the other hand, in the case of Examples 31-45 which performed microwave heating, compared with Comparative Examples 21-30, the high yield of a monoester and the high weight ratio can be made compatible. For example, for all of Examples 31-45, microwave heating can achieve a higher yield than conventional heating, whereas in conventional heating, the time change in the yield of monoester is gradual, As a result, high yields of monoesters cannot be realized. In microwave heating, such a high yield can be realized without causing odor. In Examples 32 and 38, a high yield and a high weight ratio of the monoester can be realized in a short time.

  FIG. 8 is a graph showing the change over time in the yield of monoester and the weight ratio of monoester in Examples 31 to 45 and Comparative Examples 21 to 30. In the production of sucrose lauric acid ester, first, the monoester is produced, the diester is produced from the monoester, and the triester is produced from the diester. As shown by the change in the yield of 45, the yield of the monoester gradually increases with the passage of time and starts to decrease from the middle. Moreover, since the diester etc. are produced | generated with progress of time, the ratio of a monoester will fall gradually from 100%.

  In FIG. 8, for example, when microwave heating at 130 ° C. (Examples 31 to 35) and conventional heating at 110 ° C. (Comparative Examples 21 to 25) are compared, time variation of the yield of monoester in microwave heating is changed. It can be seen that the time is shortened to about 1/12 with respect to the time change of the yield of the monoester in the conventional heating. Because it is assumed that both the change in yield up to 1 hour of microwave heating and the change in yield up to 6 hours of conventional heating are monotonically increasing, the micro-corresponding to the yield of 6 hours of conventional heating. This is because the wave heating time is about 0.5 hour. On the other hand, it can be seen that the time change of the monoester ratio in the microwave heating is not shortened to 1/12 with respect to the time change of the monoester ratio in the conventional heating. This is because the weight ratio (91.9%) of the monoester of Comparative Example 25 is smaller than the weight ratio (97.4%) of the monoester of Example 31. In this way, in the reaction of sequentially esterifying a plurality of hydroxyl groups of sucrose, when the conventional heating is changed to microwave heating, the yield of the monoester is more in the time direction than the proportion of the monoester. It can be seen that is shortened shorter. Due to the existence of such differences, microwave heating can simultaneously achieve a high yield of monoester and high selectivity in a short reaction time range (for example, a reaction time range of 6 hours or less). become.

  In addition, if FIG. 8 is referred, it turns out that the yield of the monoester in 130 degreeC microwave heating (Examples 31-35) has a peak in the heating time of 2 hours vicinity. Therefore, the time for the transesterification reaction (that is, the heating time in the subsequent step) may be the time for which the yield of the monoester reaches a peak. Here, the time when the yield of the monoester reaches a peak should theoretically be one point in time, but in reality, it is difficult to specify the point. Therefore, the time when the yield of the monoester reaches a peak may be considered as a period having a width. For example, the time for the transesterification reaction in which the yield of monoester reaches a peak in microwave heating at 130 ° C. may be considered to be in the range of 1.5 hours to 2.5 hours.

  Moreover, by comparing Examples 31-35 and Examples 36-40, it can be seen that, in the range below the decomposition temperature of sucrose, higher yields of monoester can be realized at higher reaction temperatures. . Therefore, it is considered that the reaction is preferably performed at a reaction temperature closer to the decomposition temperature of sucrose. Further, in this example, when the heating time in the subsequent step is 6 hours or less, it is possible to realize a monoester weight ratio of 65% by weight or more. In particular, when the heating time in the subsequent step is 4 hours or less, a weight ratio of the monoester of 75% by weight or more can be realized.

5. Method for producing sucrose oleate [Example 46]
A three-necked flask was charged with 107.8 g of methyl oleate heated to 60 ° C. and melted, and a solution of 3.8 g of potassium hydroxide dissolved in 30 ml of methanol. After placing the three-necked flask in a microwave reactor (μReactor EX, manufactured by Shikoku Keikaku Kogyo Co., Ltd.) equipped with a stirrer and a thermometer, the microwave was irradiated with 2.45 GHz microwave and heated to 100 ° C. while stirring. Reflux was performed for a minute. Thereafter, the pressure was maintained at 100 ° C. while reducing the pressure to 4 kPa, thereby generating potassium oleate. Moreover, after maintaining this state and removing methanol sufficiently, the content was cooled to 80 degreeC. The contents are a mixture of 87.7 g of methyl oleate and 21.7 g of potassium oleate. An aqueous solution in which 12 g of sucrose and 0.5 g of potassium hydroxide were dissolved in 8 g of water was charged into the three-necked flask. While stirring the mixture in the three-necked flask, the pressure was reduced while stirring, and the pressure was reduced to 4 kPa to evaporate water. Thereafter, microwave irradiation was performed while maintaining stirring and the degree of vacuum, and the temperature was raised to 130 ° C., and a transesterification reaction was performed for 1 hour to produce sucrose oleate. There was no odor from the start of the reaction to the end of the reaction. Therefore, the reaction could be performed at a temperature lower than the decomposition start temperature of sucrose. After completion of the reaction, sucrose oleate was obtained from the reaction product using acetone. The yield of sucrose oleate and the proportion of monoester were analyzed by high performance liquid chromatography and gas chromatography. The result is as shown in FIG.

[Examples 47 to 50]
Sucrose oleate was produced in the same manner as in Example 46 except that the time for the transesterification reaction was changed from 1 hour to 2 hours, 3 hours, 4 hours, and 6 hours. Also in this case, there was no odor from the start of the reaction to the end of the reaction. The result is as shown in FIG.

[Examples 51 to 55]
Sucrose oleate was produced in the same manner as in Examples 46 to 50 except that the temperature during the transesterification reaction was changed from 130 ° C to 120 ° C. Also in this case, there was no odor from the start of the reaction to the end of the reaction. The result is as shown in FIG.

[Examples 56 to 60]
Sucrose oleate was produced in the same manner as in Examples 46 to 50 except that the temperature during the transesterification reaction was changed from 130 ° C to 110 ° C. Also in this case, there was no odor from the start of the reaction to the end of the reaction. The result is as shown in FIG.

[Comparative Examples 31-35]
Sucrose oleate was produced in the same manner as in Examples 56 to 60 except that heating by microwave irradiation was changed to heating by an oil bath (conventional heating). In this case, there was no odor from the start of the reaction to the end of the reaction. The result is as shown in FIG.

  In addition, in the heating with an oil bath, when the temperature during the transesterification reaction was set to 130 ° C., the reaction liquid was burnt black and the sucrose was burnt. In addition, in the heating with an oil bath, when the temperature during the transesterification reaction was set to 120 ° C., the reaction solution had a burnt smell of sucrose after heating for 1.5 hours. Therefore, when heating to 120 ° C. or higher in conventional heating, it is difficult to produce sucrose oleate without odor.

[Comparative Examples 36 to 40]
Sucrose oleate was produced in the same manner as in Comparative Examples 31 to 35 except that the temperature during the transesterification reaction was changed from 110 ° C to 100 ° C. Also in this case, there was no odor from the start of the reaction to the end of the reaction. The result is as shown in FIG.

  In conventional heating, the temperature must be lowered to prevent odors from occurring. Also, when the sucrose oleate is produced by lowering the temperature in conventional heating, as can be seen from the results of Comparative Examples 31 to 40, when the yield of the monoester increases, the weight ratio of the monoester increases. The lower the monoester yield, the lower the monoester yield. On the other hand, in Examples 46-60 which performed microwave heating, compared with Comparative Examples 31-40, the high yield of a monoester and the high weight ratio can be made compatible. For example, comparing the yield of monoesters of Example 47 and Comparative Example 39 where the weight ratio of monoester is the same, microwave heating can achieve a yield of about 2.1 times that of conventional heating. Yes. In microwave heating, such a high yield can be realized without causing odor. Moreover, in conventional heating, since the time change of the yield of the monoester is gradual or the upper limit is low, a high yield of the monoester cannot be realized, but in Examples 46 to 50, etc., compared to the comparative example Thus, a higher yield can be realized. Particularly in Examples 48 and 49, a high yield and a high weight ratio of the monoester can be realized in a short time.

  FIG. 10 is a graph showing the change over time in the yield of monoester and the weight ratio of monoester in Examples 46 to 60 and Comparative Examples 31 to 40. In the production of sucrose oleate, first, a monoester is produced, a diester is produced from the monoester, and a reaction proceeds such that a triester is produced from the diester. As shown by the change in yield of 50, the yield of monoester gradually increases with the passage of time and starts to decrease from the middle. Moreover, since the diester etc. are produced | generated with progress of time, the ratio of a monoester will fall gradually from 100%.

  In FIG. 10, the time change of the conventional heating at 110 ° C. (Comparative Examples 31 to 35) is different from the time change of the conventional heating of Comparative Examples 1 to 30, and the yield of monoester in the initial stage of heating is different. The degree of increase is large, and the degree of decrease in the proportion of monoester is also large. However, in the conventional heating of Comparative Examples 31 to 35, the yield of monoester reached the upper limit in about 3 hours, and the upper limit is lower than the upper limit of the yield of monoester in microwave heating. Yes. For example, when Example 49 and Comparative Example 33 are compared, the yield of the monoester in the conventional heating is about half of the yield of the monoester in the microwave heating. Moreover, the time change of the ratio of the monoester in microwave heating has a substantially large value as a whole rather than the time change of the ratio of the monoester in the conventional heating of Comparative Examples 31-35. Therefore, microwave heating can achieve a higher monoester yield and higher selectivity than conventional heating at 110 ° C.

  In FIG. 10, for example, when the microwave heating at 130 ° C. (Examples 46 to 50) and the conventional heating at 100 ° C. (Comparative Examples 36 to 40) are compared, the yield of monoester in microwave heating is It can be seen that the time change is shorter than 1/6 with respect to the time change of the yield of monoester in the conventional heating. Because it is assumed that the change in yield up to 1 hour of microwave heating and the change in yield up to 6 hours of conventional heating are monotonically increasing, the microwave heating corresponding to the yield of 6 hours of conventional heating This is because the time is shorter than 1 hour. On the other hand, it can be seen that the time change of the monoester ratio in the microwave heating is not shortened to 1/6 with respect to the time change of the monoester ratio in the conventional heating. This is because the weight ratio (88.4%) of the monoester of Comparative Example 40 is smaller than the weight ratio (91.8%) of the monoester of Example 47. In this way, in the reaction of sequentially esterifying a plurality of hydroxyl groups of sucrose, when the conventional heating is changed to microwave heating, the yield of the monoester is more in the time direction than the proportion of the monoester. It can be seen that is shortened shorter. Due to the existence of such a difference, in microwave heating, in a short reaction time range (for example, a reaction time range within 6 hours, particularly a range within 4 hours, etc.), a high yield and high monoester yield are obtained. The selectivity can be realized at the same time.

  In addition, if FIG. 10 is referred, it turns out that the yield of the monoester in 130 degreeC microwave heating (Examples 46-50) has a peak in the heating time of about 4 hours. Therefore, the time for the transesterification reaction (that is, the heating time in the subsequent step) may be the time for which the yield of the monoester reaches a peak. Here, the time when the yield of the monoester reaches a peak should theoretically be one point in time, but in reality, it is difficult to specify the point. Therefore, the time when the yield of the monoester reaches a peak may be considered as a period having a width. For example, it may be considered that the time for the transesterification reaction in which the yield of monoester reaches a peak in microwave heating at 130 ° C. (Examples 46 to 50) ranges from 3.5 hours to 5 hours.

  In addition, by comparing Examples 46 to 50 and Examples 51 to 55, it can be seen that, in the range below the decomposition temperature of sucrose, a higher yield of monoester can be realized at a higher reaction temperature. . Therefore, it is considered that the reaction is preferably performed at a reaction temperature closer to the decomposition temperature of sucrose. Further, in this example, when the heating time in the subsequent step is 6 hours or less, a weight ratio of monoester of 60% by weight or more can be realized. In particular, when the heating time in the subsequent step is 4 hours or less, a weight ratio of monoester of 70% by weight or more can be realized.

6). Method for producing sucrose linoleic acid ester [Example 61]
A three-necked flask was charged with 107.1 g of methyl linoleate heated to 60 ° C. and melted and a solution of 3.8 g of potassium hydroxide dissolved in 30 ml of methanol. After placing the three-necked flask in a microwave reactor (μReactor EX, manufactured by Shikoku Keikaku Kogyo Co., Ltd.) equipped with a stirrer and a thermometer, the microwave was irradiated with 2.45 GHz microwave and heated to 100 ° C. while stirring. Reflux was performed for a minute. Thereafter, the temperature was maintained at 100 ° C. while reducing the pressure to 4 kPa to produce potassium linoleate. Moreover, after maintaining this state and removing methanol sufficiently, the content was cooled to 80 degreeC. The contents are a mixture of 87.1 g of methyl linoleate and 21.6 g of potassium linoleate. An aqueous solution in which 12 g of sucrose and 0.5 g of potassium hydroxide were dissolved in 8 g of water was charged into the three-necked flask. While stirring the mixture in the three-necked flask, the pressure was reduced while stirring, and the pressure was reduced to 4 kPa to evaporate water. Thereafter, microwave irradiation was performed while maintaining stirring and the degree of vacuum, and the temperature was raised to 130 ° C., and a transesterification reaction was performed for 1 hour to produce sucrose linoleic acid ester. There was no odor from the start of the reaction to the end of the reaction. Therefore, the reaction could be performed at a temperature lower than the decomposition start temperature of sucrose. After completion of the reaction, sucrose linoleic acid ester was obtained from the reaction product using acetone. The yield of sucrose linoleic acid ester and the proportion of monoester were analyzed by high performance liquid chromatography and gas chromatography. The result is as shown in FIG.

[Examples 62 to 65]
Sucrose linoleic acid ester was produced in the same manner as in Example 61 except that the time for transesterification was changed from 1 hour to 2 hours, 3 hours, 4 hours, and 6 hours. Also in this case, there was no odor from the start of the reaction to the end of the reaction. The result is as shown in FIG.

[Examples 66 to 70]
Sucrose linoleic acid ester was produced in the same manner as in Examples 61 to 65 except that the temperature during the transesterification reaction was changed from 130 ° C to 120 ° C. Also in this case, there was no odor from the start of the reaction to the end of the reaction. The result is as shown in FIG.

[Examples 71 to 75]
Sucrose linoleic acid ester was produced in the same manner as in Examples 61 to 65 except that the temperature during the transesterification reaction was changed from 130 ° C to 110 ° C. Also in this case, there was no odor from the start of the reaction to the end of the reaction. The result is as shown in FIG.

[Comparative Examples 41 to 45]
Sucrose linoleic acid ester was produced in the same manner as in Examples 71 to 75 except that heating by microwave irradiation was changed to heating by an oil bath (conventional heating). In this case, there was no odor from the start of the reaction to the end of the reaction. The result is as shown in FIG.

  In addition, in the heating with an oil bath, when the temperature during the transesterification reaction was set to 130 ° C., the reaction liquid was burnt black and the sucrose was burnt. In addition, in the heating with an oil bath, when the temperature during the transesterification reaction was set to 120 ° C., the reaction solution had a burnt smell of sucrose after heating for 1.5 hours. Therefore, when heating to 120 ° C. or higher in conventional heating, it is difficult to produce a sucrose linoleic acid ester without odor.

[Comparative Examples 46-50]
Sucrose linoleic acid ester was produced in the same manner as in Comparative Examples 41 to 45 except that the temperature during the transesterification reaction was changed from 110 ° C to 100 ° C. Also in this case, there was no odor from the start of the reaction to the end of the reaction. The result is as shown in FIG.

  In conventional heating, the temperature must be lowered to prevent odors from occurring. Also, when the sucrose linoleic acid ester is produced by lowering the temperature in the conventional heating, as can be seen from the results of Comparative Examples 41 to 50, when the yield of the monoester increases, the weight ratio of the monoester increases. The lower the monoester yield, the lower the monoester yield. On the other hand, in the case of Examples 61-75 which performed microwave heating, compared with Comparative Examples 41-50, the high yield of a monoester and the high weight ratio can be made compatible. For example, comparing the yield of monoesters of Example 62 and Comparative Example 49 in which the monoester weight ratio is the same, microwave heating can achieve a yield of about 1.8 times that of conventional heating. Yes. In microwave heating, such a high yield can be realized without causing odor. Moreover, in the conventional heating, since the time change of the yield of the monoester is gradual or the upper limit is low, a high yield of the monoester cannot be realized. Thus, a higher yield can be realized. Particularly in Examples 63 and 64, a high yield and a high weight ratio of the monoester can be realized in a short time.

  FIG. 12 is a graph showing the change over time in the yield of monoesters in Examples 61-75 and Comparative Examples 41-50 and the weight ratio of monoesters. In the production of sucrose linoleic acid ester, first, a monoester is produced, a diester is produced from the monoester, and a triester is produced from the diester. As shown by the change in the yield of 65, the yield of the monoester gradually increases with the passage of time and starts to decrease from the middle. Moreover, since the diester etc. are produced | generated with progress of time, the ratio of a monoester will fall gradually from 100%.

  In FIG. 12, the time change of the conventional heating at 110 ° C. (Comparative Examples 41 to 45) is different from the time change of the conventional heating of Comparative Examples 1 to 30, and the monoester yield in the initial stage of heating is different. The degree of increase is large, and the degree of decrease in the proportion of monoester is also large. However, in the conventional heating of Comparative Examples 41 to 45, the yield of monoester reached the upper limit in about 2 hours, and the upper limit is lower than the upper limit of the yield of monoester in microwave heating. Yes. For example, when Example 64 and Comparative Example 42 are compared, the yield of the monoester in the conventional heating is about half (about 0.57) of the yield of the monoester in the microwave heating. Moreover, the time change of the ratio of the monoester in microwave heating has a substantially large value as a whole rather than the time change of the ratio of the monoester in the conventional heating of Comparative Examples 41-45. Therefore, microwave heating can achieve a higher monoester yield and higher selectivity than conventional heating at 110 ° C.

  Moreover, in FIG. 12, for example, when microwave heating at 130 ° C. (Examples 61 to 65) and conventional heating at 100 ° C. (Comparative Examples 46 to 50) are compared, the yield of monoester in microwave heating is It can be seen that the time change is shorter than 1/6 with respect to the time change of the yield of monoester in the conventional heating. Because it is assumed that the change in yield up to 1 hour of microwave heating and the change in yield up to 6 hours of conventional heating are monotonically increasing, the microwave heating corresponding to the yield of 6 hours of conventional heating This is because the time is shorter than 1 hour. On the other hand, it can be seen that the time change of the monoester ratio in the microwave heating is not shortened to 1/6 with respect to the time change of the monoester ratio in the conventional heating. This is because the weight ratio (89.8%) of the monoester of Comparative Example 50 is smaller than the weight ratio (90.0%) of the monoester of Example 62. In this way, in the reaction of sequentially esterifying a plurality of hydroxyl groups of sucrose, when the conventional heating is changed to microwave heating, the yield of the monoester is more in the time direction than the proportion of the monoester. It can be seen that is shortened shorter. Due to the existence of such a difference, in microwave heating, in a short reaction time range (for example, a reaction time range within 6 hours, particularly a range within 4 hours, etc.), a high yield and high monoester yield are obtained. The selectivity can be realized at the same time.

  In addition, if FIG. 12 is referred, it turns out that the yield of the monoester in 130 degreeC microwave heating (Examples 61-65) peaks at the heating time of about 4 hours. Therefore, the time for the transesterification reaction (that is, the heating time in the subsequent step) may be the time for which the yield of the monoester reaches a peak. Here, the time when the yield of the monoester reaches a peak should theoretically be one point in time, but in reality, it is difficult to specify the point. Therefore, the time when the yield of the monoester reaches a peak may be considered as a period having a width. For example, the time for the transesterification reaction in which the yield of the monoester reaches a peak in microwave heating at 130 ° C. (Examples 61 to 65) may be considered to be in the range of 3.5 hours to 5 hours.

  Further, by comparing Examples 61 to 65 and Examples 66 to 70, it is inferred that the higher the reaction temperature, the higher the yield of the monoester can be realized in the range below the decomposition temperature of sucrose. it can. Therefore, it is considered that the reaction is preferably performed at a reaction temperature closer to the decomposition temperature of sucrose. Further, in this example, when the heating time in the subsequent step is 6 hours or less, a weight ratio of monoester of 60% by weight or more can be realized. In particular, when the heating time in the subsequent step is 4 hours or less, a weight ratio of monoester of 70% by weight or more can be realized.

  In each of the above Reference Examples and Examples, the constituent fatty acids of the fatty acid ester are palmitic acid (16 carbon atoms; saturated fatty acid), stearic acid (18 carbon atoms; saturated fatty acid), caprylic acid (8 carbon atoms; saturated fatty acid), In the case of lauric acid (carbon number 12; saturated fatty acid), oleic acid (carbon number 18; monovalent unsaturated fatty acid), linoleic acid (carbon number 18; polyunsaturated fatty acid), microwave irradiation Thus, it has been explained that the production of a sucrose fatty acid ester having a high monoester ratio and no odor can be realized in a high yield. Therefore, it can be inferred that the same effect can be obtained also in the production of sucrose fatty acid ester using fatty acid ester having a fatty acid having 8 to 24 carbon atoms as a constituent fatty acid. Further, it can be inferred that the same effect can be obtained regardless of whether the constituent fatty acid of the fatty acid ester used in the production of the sucrose fatty acid ester is a saturated fatty acid other than the above or an unsaturated fatty acid other than the above. Furthermore, it can be inferred that the same effect can be obtained regardless of the number of unsaturated bonds in the unsaturated fatty acid.

  In addition, this invention is not limited to the above Example, A various change is possible, and it cannot be overemphasized that they are also included in the scope of the present invention.

  The sucrose fatty acid ester obtained by the method for producing a sucrose fatty acid ester according to the present invention can be used, for example, in the fields of food, cosmetics, pharmaceuticals and the like.

Claims (7)

Preparing an aqueous solution containing sucrose and a basic catalyst;
The sucrose fatty acid ester is obtained by mixing the aqueous solution obtained in this step, a fatty acid alkali metal salt, and a fatty acid ester (excluding palmitic acid ester and stearic acid ester), stirring and heating under reduced pressure. A step of generating,
The step of producing the sucrose fatty acid ester has a previous step of removing water from the mixture, and a subsequent step of performing transesterification after the step,
In the subsequent step, a method for producing a sucrose fatty acid ester, wherein the mixture is heated by irradiation with microwaves so that the mixture is lower than the decomposition temperature of the sucrose. The manufacturing method of the sucrose fatty acid ester of Claim 1 whose manufacturing object is a sucrose fatty acid ester whose weight ratio of a monoester is 60 weight% or more. The fatty acid ester is a fatty acid ester (excluding palmitic acid ester and stearic acid ester) having at least one selected from saturated and unsaturated fatty acids having 8 to 24 carbon atoms as a constituent fatty acid. The manufacturing method of the sucrose fatty acid ester of Claim 2. Further comprising the step of producing a fatty acid alkali metal salt by mixing and heating a fatty acid ester and a solution in which the alkali metal salt is dissolved in a solvent;
The sucrose according to any one of claims 1 to 3, wherein the fatty acid alkali metal salt used in the step of producing the sucrose fatty acid ester is produced in the step of producing the fatty acid alkali metal salt. A method for producing a fatty acid ester. The method for producing a sucrose fatty acid ester according to any one of claims 1 to 4, wherein in the subsequent step, the mixture is heated so that the temperature of the mixture is 25 ° C lower than the decomposition temperature and lower than the decomposition temperature. . The method for producing a sucrose fatty acid ester according to any one of claims 1 to 5, wherein in the subsequent step, the mixture is heated so as to increase in temperature. The method for producing a sucrose fatty acid ester according to any one of claims 1 to 6, wherein a heating time in the subsequent step is 6 hours or less.

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