JP2006169237A - Sucrose fatty acid ester having low degree of substitution and method for producing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a sucrose fatty acid having a low average degree of substitution suitable for food emulsifiers and the like in high quality by solving problems: complicated removal of solvents and high viscosity in reaction liquids in conventional methods. <P>SOLUTION: The method for producing the sucrose fatty acid having the low degree of substitution is to reduce the degree of substitution of a raw sucrose fatty acid ester. In the method, the raw sucrose fatty acid ester is reacted with activated sucrose in the presence of a solvent having ≤35.0 (20°C) relative permitivity and no hydroxyl groups or a solvent having ≤150°C (under normal pressure) boiling point, ≤50g/100ml (20°C) solubility to water and no hydroxyl groups. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a low-substituted sucrose fatty acid ester and a method for producing the same. In particular, the present invention relates to a low-substituted sucrose fatty acid ester having high hydrophilicity and useful in the food field and the like and a method for producing the same.

  A sucrose fatty acid ester (hereinafter sometimes abbreviated as SE) is a substance in which at least a part of eight hydroxyl groups in a sucrose molecular skeleton is esterified with a fatty acid. Since the ester substitution degree of SE has a distribution, it is usually represented by an average substitution degree (hereinafter, also simply referred to as “substitution degree”).

SE has a wide range of HLB values that are measures of hydrophilicity and lipophilicity, and is widely used as a surfactant for foods. SE having a low degree of substitution has a high HLB value, that is, high hydrophilicity, and is used as an emulsifier for foods such as an oil-in-water dispersion type (O / W type) emulsion stabilizer such as coffee with milk. High market value and high demand.
Many proposals have been made for the production method of SE. These methods are roughly classified into the following three types.

  The first method is a method called a solvent method. This is a reaction method using a good solvent for both sucrose and fatty acid derivatives such as dimethylformamide (DMF) and dimethyl sulfoxide (DMSO). As a specific example, sucrose and fatty acid methyl ester are reacted in DMSO at about 90 ° C. in the presence of an alkali catalyst. In this reaction, methanol is by-produced, and the reaction is carried out while removing this. In particular, when SE is used for food applications, it is necessary to reduce the residual solvent. Accordingly, when SE having a low degree of substitution is produced by this method, solvent removal equipment such as multistage extraction and crystallization is required, and the operation technique is complicated. Even if the solvent removal treatment is performed, a trace amount (for example, about 0.3 ppm in the case of DMSO) actually remains.

  The second method is a method generally called a microemulsion method. In this method, a solution in which sucrose is dissolved in propylene glycol and water, and a fatty acid derivative such as fatty acid methyl ester are converted into a very fine dispersion using an emulsifier such as fatty acid soap, that is, a microemulsion, It is the method of making it react after removing (refer patent document 1). However, the process of removing the solvent while maintaining the microemulsion state requires advanced techniques, and the reaction is generally performed at a high temperature of 100 to 150 ° C., but it is 100 ° C. or higher, particularly 120 ° C. or higher. When heated to high, sucrose is likely to decompose.

  The microemulsion method has not been used for the production of low substitution SE. This is presumed to be due to the following reason. In order to obtain SE with a low degree of substitution, it is necessary to use a large excess of the amount of sucrose used relative to the fatty acid derivative to be esterified. Also, since fatty acid methyl esters decrease with the progress of the reaction, if the reaction is attempted to proceed almost completely, the reaction solution becomes highly viscous and stirring becomes difficult, raising the temperature or using a special stirring device. It is necessary to deal with it. Further, when propylene glycol is used as a solvent, propylene glycol ester remains in the reaction solution.

The third method is a method in which sucrose and a fatty acid ester are directly mixed and reacted at 100 to 150 ° C. without using a solvent, and is called a direct method. Since sucrose and fatty acid esters do not have an affinity for each other, in the direct method, it is important how to mix both raw materials so that they react smoothly. In general, this reaction is carried out using alkali soap as a mixing aid and heating to the same level or higher than in the microemulsion method. Therefore, decomposition of sucrose by heating is likely to occur. The direct method has not been used to produce low substitution SE. The reason why the direct method is not used for the production of the low substitution degree SE is considered to be due to the same cause as in the microemulsion method. In the direct method, a method of transesterification between SE and sucrose has also been proposed (see Patent Documents 2 and 3). However, this method also has the problem of increasing the viscosity described above.
Japanese Patent Publication No. 51-14485 Japanese Examined Patent Publication No. 4-65080 JP 59-78200 A

  The object of the present invention is to provide a method for obtaining a high-quality, low-substituted sucrose fatty acid ester that is industrially superior and suitable for food emulsifiers, etc., without the complicated solvent removal operation in the conventional method. To do.

As a result of intensive studies to solve the above-mentioned problems, the present inventors have used a solvent having specific physical properties and activated sucrose in a transesterification reaction between sucrose and SE, whereby high quality, low substitution degree SE. Has been found to be industrially advantageous, and the present invention has been achieved.
That is, the gist of the present invention is a method for producing a low-substituted sucrose fatty acid ester by reducing the substitution degree of the raw sucrose fatty acid ester, wherein the raw sucrose fatty acid ester and the activated sucrose are mixed at 20 ° C. In the method for producing a low-substitution sucrose fatty acid ester, the reaction is carried out in the presence of a solvent having a relative dielectric constant of 35.0 or less and having no hydroxyl group.

  Another gist of the present invention is a method for producing a low-substituted sucrose fatty acid ester by reducing the substitution degree of the raw sucrose fatty acid ester, wherein the raw sucrose fatty acid ester and the activated sucrose are subjected to normal pressure. The low-substitution sucrose fatty acid ester has a boiling point of 150 ° C. or lower, a solubility in water at 20 ° C. of 50 g / 100 ml or lower, and a reaction in the presence of a solvent having no hydroxyl group. Exist in the manufacturing method. Further, the further gist includes an average substitution degree of 1.0 to 1.6, a relative dielectric constant at 20 ° C. of 35.0 or less, and a solvent [solvent (a)] having no hydroxyl group. A low-substituted sucrose fatty acid ester, which is a low-substituted sucrose fatty acid ester comprising no solvent (except water, methanol and ethanol) other than the solvent (a), and an average degree of substitution 1.0 to 1.6, the boiling point at normal pressure is 150 ° C. or less, the solubility in water at 20 ° C. is 50 g / 100 ml or less, and the solvent [solvent (b)] has no hydroxyl group. A low-substituted sucrose fatty acid ester comprising a low-substituted sucrose fatty acid ester comprising no solvent (except water, methanol and ethanol) other than the solvent (b) Existence That.

  The following are mentioned as a suitable aspect of this invention method. That is, using a solvent having a relative dielectric constant of 1.1 to 20.0 at 20 ° C. as a solvent, reducing the average substitution degree of the raw sucrose fatty acid ester by 0.2 or more, and producing a low substitution degree sucrose The average substitution degree of the fatty acid ester is 1.0 to 2.0, the average substitution degree of the raw sucrose fatty acid ester is 1.5 to 5.0, and the raw sucrose fatty acid ester has 8 to 22 carbon atoms. The fatty acid, the raw sucrose fatty acid ester and the activated sucrose are reacted in the presence of fatty acid soap, and the amount of Ash in the low-substituted sucrose fatty acid ester is 6.0% by weight or less. In other words, 70 to 100% of the fatty acid constituting the low-substituted sucrose fatty acid ester is palmitic acid.

  According to the method of the present invention, a sucrose fatty acid ester having a low substitution degree can be obtained without using a solvent that is difficult to remove. That is, by using a reaction solvent having specific physical properties, the reaction solvent in the low-substituted sucrose fatty acid ester can be removed to about 1 ppm by a simple operation such as distillation or evaporation. Therefore, complicated operations such as multistage extraction of solvents and crystallization operations, which are necessary for obtaining a high-quality product in the conventional solvent method, become unnecessary. As a result, the capital investment cost can be kept very low, and the operation technique is greatly simplified. In particular, when the reaction solvent is a poor solvent for sucrose, the reaction solvent can be used as it is as a solvent for removing unreacted sucrose from the SE synthesis reaction product by phase separation or the like. As a result, the number of solvents used in SE production can be reduced, so that the solvent recovery can be simplified and the capital investment cost can be kept low.

  In the method of the present invention, the reaction can be performed at a lower temperature than the direct method or the microemulsion method, as in the conventional solvent method. Since the thermal decomposition of sucrose hardly occurs at a low reaction temperature, it is suitable for producing high-quality SE, particularly SE with a low degree of substitution. Therefore, the method of the present invention is very useful as an industrial process for producing a high-quality, low-substituted SE.

  Hereinafter, the present invention will be described in detail. However, the description of the constituent elements described below is a representative example of the embodiment of the present invention, and is not limited to these contents.

In the transesterification reaction between SE and sucrose, the method of the present invention uses activated sucrose as sucrose and reacts with a solvent having specific physical properties, thereby making the substitution rate of the raw sucrose fatty acid ester higher than the substitution degree. A sucrose fatty acid ester having a low substitution degree is produced.
<Raw material sucrose fatty acid ester (raw material SE)>
Any of 1-8 may be sufficient as the substitution degree of sucrose fatty acid ester (raw material SE) used as a reaction raw material in this invention. A mixture of sucrose fatty acid esters having different degrees of ester substitution may be used. In order to produce a low-substituted sucrose fatty acid ester (low-substituted SE), the lower limit of the average degree of substitution of the ester of the raw material SE is preferably 1.5, more preferably 2.0. The upper limit is preferably 5.0.

  The production method of the raw material SE is not particularly limited, and may be a single SE obtained by any of the above-described methods, or a mixture of SE obtained by a plurality of methods. In the method of the present invention, in order to obtain a high-quality, low-substituted sucrose fatty acid ester, it is preferable to use, as the raw material SE, SE produced by an emulsion method or a direct method without accompanying a reaction solvent.

  The fatty acid constituting the ester bond of SE is not particularly limited. The thing etc. which mixed multiple types of fatty acid by arbitrary ratios may be sufficient. Usually, a saturated or unsaturated fatty acid having 4 to 30 carbon atoms such as lauric acid, myristic acid, palmitic acid, oleic acid, stearic acid and erucic acid can be used. Among these, from the viewpoint of the function as an emulsifier, a saturated or unsaturated fatty acid having 8 to 22 carbon atoms is preferable. Moreover, when using for a food emulsifier etc., a palmitic acid or a stearic acid is preferable. In particular, since emulsification of coffee beverages has a bacteriostatic action, palmitic acid is preferably used, and preferably 70% or more, more preferably 80% or more of fatty acids constituting the ester bond of SE. Is good. The upper limit of the ester bond is 100%.

<Reaction solvent>
The reaction solvent used in the method of the present invention usually has a relative dielectric constant at 20 ° C. of 35.0 or less. The relative dielectric constant is an index of the polarity of the molecule, and is usually measured with an external electric field having a frequency of about 1 MHz. Specific values of the dielectric constant are described in, for example, Chemical Handbook 5th revision II, pages 619 to 623, and the revised 4th edition II, pages 498 to 501. The lower limit of the relative permittivity of the reaction solvent at 20 ° C. is preferably 1.1, more preferably 2.3, the upper limit is preferably 20.0, and 19.0. Further preferred.
In addition, as the reaction solvent used in the method of the present invention, a solvent having no hydroxyl group is used because it does not form an ester during the reaction. A reaction solvent may be used individually by 1 type, or may mix and use 2 or more types.

  Specifically, the solubility of the reaction solvent used in the method of the present invention in water is preferably 50 g / 100 ml or less, particularly preferably 30 g / 100 ml or less at 20 ° C. Further, the lower limit of the solubility of the reaction solvent in water is usually 0.001 g / 100 ml. In general, a solvent having a relative dielectric constant of 35.0 or less at 20 ° C. has a low polarity, and thus has a low solubility in water, and a solvent having a low solubility in water is a poor solvent for sucrose. In the method of the present invention, unreacted sucrose remaining after the reaction can be removed by phase separation with water, crystallization, or the like. Here, when the solubility of the reaction solvent in water and sucrose is low, sucrose can be easily removed together with water when the unreacted sucrose is phase-separated and removed on the aqueous phase side. If the reaction solvent is a poor solvent for sucrose, it is easy to remove sucrose by crystallization. Accordingly, the solvent used in the method of the present invention is preferably a poor solvent for sucrose.

  Conventionally, it was thought that the solvent used for the synthesis reaction of SE had to dissolve sucrose. And it was thought that it was substantially impossible to make sucrose react with fatty acid derivatives, such as fatty acid methyl ester, SE, etc. using the poor solvent with respect to sucrose. In particular, it has been considered practically impossible to use a solvent conventionally used for the synthesis reaction of SE as a reaction solvent for the low-substitution SE synthesis because the reaction rate is extremely low. In general, solvents commonly used in SE synthesis reactions such as DMF, DMSO, and propylene glycol can be mixed with water at 20 ° C. in an arbitrary ratio. However, in the method of the present invention, by using activated sucrose, even a poor solvent for such sucrose can be used. In the method of the present invention, the solvent is mainly used to lower the viscosity of the reaction solution.

  Also, a solvent having a relative dielectric constant at 20 ° C. of 35.0 or less usually has a low boiling point because of its low polarity. The boiling point of the reaction solvent used in the method of the present invention is preferably not too low than the reaction temperature. The method of the present invention is usually carried out at 80 to 110 ° C., preferably at about 90 ° C. under normal pressure. Therefore, the boiling point of the solvent is preferably 70 to 150 ° C., more preferably 70 to 120 ° C. under normal pressure. However, since the reaction temperature can be changed according to reaction conditions such as reaction pressure, a solvent having a lower boiling point or higher boiling point can be used. In addition, the boiling point under the normal pressure of the solvent normally used for manufacture of SE is as follows. DMF 153.0 ° C, DMSO 189.0 ° C, propylene glycol 187.4 ° C, water 100.0 ° C.

  Specific examples of the reaction solvent used in the method of the present invention include the following, but the reaction solvent used in the method of the present invention is not limited thereto. The values in parentheses represent the relative dielectric constant at 20 ° C., the solubility in water at 20 ° C. (g / 100 ml), and the boiling point under normal pressure. Ketones such as methyl ethyl ketone (18.6, 29.0, 79.8), acetone (21.0, freely mixed with water), 56.1); toluene (2.4, 0.045, 110.8) ), Xylene (2.6, 0.02, 144.6), hexane (1.9, 0.0013, 68.9) and other hydrocarbons; chloroform (4.8, 0.8, 61.3) ), Chlorinated hydrocarbons such as chlorobenzene (5.7, 0.05, 131.9). Of these, methyl ethyl ketone or hydrocarbons are preferred, methyl ethyl ketone and toluene are more preferred, and methyl ethyl ketone is particularly preferred when used as a food additive because the reaction temperature can be set at 80 to 90 ° C. and chemical stability.

<Activated sucrose>
Sucrose to be reacted with SE in the method of the present invention is activated sucrose. Activated sucrose is a substance in which at least a part of protons of the hydroxyl group of sucrose is bonded to an alkali metal or an alkaline earth metal.

Specific examples of the activated sucrose include (1) a succinate anion in which at least a part of protons in the hydroxyl group of sucrose is substituted with an alkali metal and / or an alkaline earth metal, and (2) a metal (alkali Metal and / or alkaline earth metal) and / or metal compounds (alkali metal and / or alkaline earth metal alkoxides, carbonates, bicarbonates, hydrides, hydroxides, etc.) and sucrose complexes, etc. Is mentioned. The activated sucrose used in the method of the present invention may be one kind or a mixture of two or more kinds. Activated sucrose also includes emulsifiers such as soap containing the above substances.
It is presumed that activated sucrose is in an amorphous state because a part of hydrogen bonds of the sucrose is broken. Thus, a simple mixture of sucrose and an alkali metal or alkaline earth metal is not included in the activated sucrose.

As the alkali metal and alkaline earth metal in which protons are substituted with activated sucrose, alkali metals such as sodium and potassium are preferable, and potassium is particularly preferable because it is used for catalytic activity at the time of transesterification and food. . These metals are preferably hydroxides because they are easily dissolved in water and alcohol used in the preparation of activated sucrose.
The activation of sucrose can be confirmed by crystal structure analysis such as X-ray diffraction analysis and near infrared spectrophotometric analysis.

  Various methods for sucrose activation have been proposed so far. The activated sucrose used in the method of the present invention may be sucrose activated by any of these known methods. Moreover, what was obtained by methods other than these may be used.

Examples of a simple method for preparing activated sucrose include the following methods.
That is, a compound of sucrose and an alkali metal or alkaline earth metal (for example, a salt such as a hydroxide) is mixed with water and an alcohol (for example, methanol, ethanol, etc.) and sufficiently dissolved, and then an evaporator. In this method, water and alcohol are removed to 0.1% by weight or less by drying using a liquid. The ratio (molar ratio) of the alkali metal or alkaline earth metal compound used in the preparation of the activated sucrose to sucrose is preferably 5.0 or less, because sucrose is not easily decomposed by heating. The following is more preferable, and 0.2 or less is particularly preferable. The lower limit is usually 0.01.

  The amount of water used in this method is sufficient as long as it can dissolve sucrose, and is not particularly limited. In this method, the alcohol is used for the purpose of azeotropic removal of water from the activated sucrose. Therefore, as long as this purpose is achieved, the amount of alcohol used is not particularly limited. Furthermore, the order in which sucrose and these substances are mixed is not particularly limited. However, since sucrose is hardly decomposed, it is preferable to dry and remove the solvent at 90 ° C. or less, particularly at about 60 ° C.

When fatty acid soap is used as an emulsifier in the production of raw material SE, fatty acid soap and its precursor fatty acid and alkali metal (compound), fatty acid monoglyceride, etc. are contained even in the activation of sucrose. Also good.
As a method for activating sucrose, in addition to the above-mentioned method, J. appl. Chem. , 9, March, 1959, 186-192: ARNI et al. And Adv. In Carbohydr. Chem. 21 (1966), 209-269: J. A. Rendleman, Jr. And the like described in the literature.

<Reaction raw materials, substances other than solvents>
In the method of the present invention, a substance other than the reaction raw material and the solvent may be present in the reaction system as long as the progress of the transesterification reaction between the activated sucrose and the raw material SE is not significantly hindered. Specifically, for example, an emulsifier such as fatty acid soap, fatty acid monoglyceride or a precursor thereof may be supplied to the reaction system together with the activated sucrose. What is necessary is just to show the effect which mixes a raw material with the kind and quantity of an emulsifier. As the fatty acid soap, fatty acid K soap, fatty acid Na soap or the like is usually used. The fatty acid soap is preferably composed of a fatty acid having 4 to 22 carbon atoms and an alkali metal because it is excellent in emulsifying and mixing the reaction raw material and the solvent. Since the amount of fatty acid soap used is excellent for emulsifying and mixing the reaction raw material and solvent, the lower limit is 5% by weight, particularly 10%, based on the total amount of raw material SE, activated sucrose and fatty acid soap. % By weight and the upper limit is preferably 60% by weight, especially 50% by weight. Moreover, since fatty acid monoglyceride is excellent in emulsifying and mixing a reaction raw material and a solvent, what is an ester of C4-C22 fatty acid and glycerol is preferable. This may contain a part of diglyceride and triglyceride.

  In addition, in a state after reaction by a direct method (a state where SE, sucrose, fatty acid soap, catalyst, fatty acid methyl ester, etc. are present), activated sucrose and the reaction solvent of the method of the present invention are added thereto. By this, the transesterification of SE in the reaction product can be advanced to obtain SE with a low degree of substitution.

<Manufacturing method>
The method of the present invention will be described.
In the transesterification reaction of the present invention, the lowering degree (average) of the degree of substitution from the raw material SE to the low degree of substitution SE is preferably 0.2, preferably 0.5, more preferably 0.8. . Note that the upper limit of the degree of reduction in the degree of substitution is usually 4.0, preferably 1.2. The degree of substitution reduction by the method of the present invention includes the type of raw material SE and the degree of substitution, the type of activated sucrose and the amount of activated sucrose used, the type of solvent, reaction conditions such as reaction temperature and reaction time, desired Depends on the degree of substitution of the low substitution degree SE.

What is necessary is just to adjust suitably the usage-amount of the activated sucrose in transesterification of the method of this invention so that the substitution degree of SE may fall to a desired value.
The amount of the solvent used in the reaction is such that the reaction solution can be stirred even if the viscosity of the reaction solution increases with the progress of the reaction. In addition, even if there are too many solvents, it is not preferable because it takes time to remove the solvent after the reaction. Specifically, the amount of the solvent used is usually preferably 10 to 70% by weight, more preferably 40 to 70% by weight, based on the entire reaction solution.

The reaction temperature may be any temperature as long as the substitution degree of SE can be lowered by the transesterification of the present invention. The reaction temperature is preferably higher in terms of the reaction rate, and the lower one is preferable in terms of the quality of the obtained low substitution degree SE because decomposition of sucrose hardly occurs. From these viewpoints, the reaction temperature is normal pressure, usually 80 to 110 ° C, preferably about 90 ° C. The reaction pressure may be normal pressure, reduced pressure, or increased pressure as long as the transesterification of the present invention proceeds. However, the reaction under extreme pressure requires an expensive apparatus and sucrose is likely to be decomposed. The atmosphere during the reaction may be any atmosphere as long as it does not significantly interfere with the reaction of the present invention, but from the viewpoint of safety, an inert atmosphere such as N ₂ or Ar is preferable.

  The reaction time is the time for SE to fall to the desired degree of substitution until the transesterification reaction of the present invention is completed. What is necessary is just to select reaction time suitably according to other reaction conditions, such as the fall of a substitution degree, and reaction temperature. Specifically, the reaction time is usually 1 hour or longer, preferably 3 hours or longer, and usually 15 hours or shorter, preferably 10 hours or shorter. Even if the reaction solvent is a poor solvent for sucrose, it is unclear why the reaction rate of low substitution SE synthesis is not extremely slowed by using activated sucrose. Usually, hydrogen bonds are formed between hydroxyl groups of sucrose molecules. When the sucrose is activated, this hydrogen bond is broken and the hydroxyl group of the sucrose molecule and the ester site of SE are easily brought into contact with each other, so that the reaction rate is presumed not to be extremely slow.

The reaction solution is usually stirred. As the stirring method, an appropriate method may be selected according to the viscosity of the reaction solution. For example, when the amount of solvent is about 70% by weight of the reaction solution, stirring is often performed with an anchor type or half moon type stirring blade. If stirring is difficult, the amount of solvent may be increased. The stirring speed may be any speed that promotes mixing of the reactants, and is usually 10 to 1000 rpm. The reaction apparatus is preferably an apparatus that can completely reflux the solvent evaporated during the reaction and return it to the reaction vessel.
The end point of the reaction can be determined by a change in viscosity of the reaction solution. When the reaction is completed, a post-treatment such as quenching or neutralization with an acid is usually performed.

In the conventional solvent method, a good solvent for sucrose and fatty acid derivatives such as DMF is used, and in order to remove this from SE after the reaction, a special apparatus and complicated unit operation are required. On the other hand, in the method of the present invention, a solvent having a low polarity is used. Since the solvent usually has a relatively low boiling point, the residual solvent in the SE after reaction can be obtained by a simple operation such as distillation or evaporation. Can be removed. The amount of residual solvent in the low substitution degree SE obtained by the method of the present invention can be quantified by gas chromatography. The amount of residual solvent in the low substitution degree SE obtained by the method of the present invention can be removed preferably to about several ppm, more preferably to about 1 ppm.
The reaction solvent used in the method of the present invention can also be used in the post-treatment of the present invention. That is, a solvent that can be used as a reaction solvent of the method of the present invention is brought into contact with the reaction mixture after completion of the reaction of the method of the present invention, and water or the like is further added as necessary. By contacting, unreacted sucrose and fatty acid soap can be removed from the reaction product by performing extraction by phase separation, crystallization operation, and the like, and the process can be simplified.

<Low-substituted sucrose fatty acid ester (low-substituted SE)>
The degree of substitution of the low-substituted sucrose fatty acid ester obtained by the method of the present invention varies depending on its use and is not particularly limited. The average substitution degree of the low-substituted sucrose fatty acid ester obtained by the method of the present invention is usually 1.0 to 2.0, preferably 1.0 to 1.6, more preferably 1.0 to 1. 4.

  According to the method of the present invention, a low-substituted sucrose fatty acid ester can be obtained without using a solvent that is difficult to remove from the produced SE. That is, as the raw material SE, SE synthesized without using a solvent that is difficult to remove such as an emulsion method or a direct method is used, and when the low substitution reaction of the method of the present invention is performed on this, other than the solvent used in the method of the present invention. A low substitution SE without a solvent can be obtained. Here, since the low-substituted sucrose fatty acid ester produced by the method of the present invention may be subjected to removal of unreacted activated sucrose after the reaction by water extraction, it may contain water in some cases. Yes, and may also contain methanol (MeOH) and ethanol (EtOH) by-produced in the esterification reaction. Therefore, the low-substituted sucrose fatty acid ester produced by the method of the present invention may contain water, methanol and ethanol.

  Specifically, according to the method of the present invention, a solvent [solvent (a)] having an average substitution degree of 1.0 to 1.6, a relative dielectric constant at 20 ° C. of 35.0 or less, and having no hydroxyl group is obtained. It is possible to obtain a low substitution SE comprising a low substitution degree sucrose fatty acid ester comprising a solvent other than the solvent (a) (excluding water, methanol and ethanol). . Moreover, according to the method of the present invention, the average degree of substitution is SE of 1.0 to 1.6, the boiling point at normal pressure is 150 ° C. or less, and the solubility in water at 20 ° C. is 50 g / 100 ml or less, And a low-substituted sucrose fatty acid ester comprising a solvent having no hydroxyl group [solvent (b)], including a solvent other than the solvent (b) (excluding water, methanol and ethanol) Low substitution degree SE can be obtained. In addition, it can confirm simply that a solvent is not included by gas chromatography. Further, it can be confirmed more accurately by mass spectrometry that no solvent is contained.

  In the method of the present invention, the reaction can be allowed to proceed in a state where decomposition of sucrose is suppressed. When sucrose is decomposed, monosaccharides, monosaccharide esters, caramelized products, and the like are included in the obtained low substitution degree SE. The amount of monosaccharide, monosaccharide ester and caramelized product in SE can be quantified by gas chromatography.

  The amount of Ash in the low substitution SE obtained by the method of the present invention is usually 6.0% by weight or less, preferably 5.0% by weight or less, and more preferably 2.0% by weight or less. The lower limit of the amount of Ash is usually 0.1% by weight. Ash is an ignition residue. The amount of Ash is the amount of a substance remaining after adding sulfuric acid to 2 to 4 g of a sample and igniting. For example, sulfuric acid is added to 3 g of the sample, and the residue weight when heated at 450 to 550 ° C. for 3 hours is 0.15 g / 3 g = 5 wt%. Specifically, it can be quantified based on the 7th edition (Yodogawa Shoten) B-59 “Ignition Residue Test Method” of the Food Additives Official Document.

EXAMPLES Next, although an Example demonstrates this invention further in detail, this invention is not limited to these Examples, unless the summary is exceeded.
In the following examples,% is based on weight.

Example 1
<Preparation of activated sucrose>
In an eggplant-shaped flask, 250.0 g of sucrose, 75.0 g of KOH, 305.3 g of palmitic acid, 790.0 g of methanol, and 290.0 g of water were added, and each component was dissolved by heating and mixing at 60 ° C. for 30 minutes. (Here, almost all of palmitic acid and a part of KOH reacted to produce potassium soap palmitate, and the remaining KOH was used to activate sucrose.) Using an evaporator, the liquid was dried under reduced pressure at 60 ° C. so that sucrose was not decomposed (when foaming due to palmitic acid soap occurred during drying under reduced pressure). Methanol and water were removed while suppressing foam by N ₂ stripping). The obtained white powder was pulverized in a mortar. The water content in the white powder was measured by the Karl Fischer method and found to be 0.1% by weight or less.

<Reaction of raw material SE with activated sucrose>
26.9 g of white powder containing activated sucrose prepared by the above method, sucrose fatty acid ester (“Ryoto Sugar Ester S570” manufactured by Mitsubishi Chemical Foods, Inc., ratio of constituent fatty acids; stearic acid: palmitic acid = 70: 30 The average substitution degree (actual measurement value: 2.22) 5.0 g and methyl ethyl ketone (MEK) 21.3 g were charged into a round bottom eggplant-shaped flask at room temperature. While the inside of the round bottom eggplant-shaped flask is in an N ₂ atmosphere, the reaction liquid in the flask is sufficiently stirred at 410 rpm using a motor-driven stirring blade (half moon type), and a 90 ° C. oil bath is used. And heated. In this state, the reaction was carried out at normal pressure for 6.0 hours while completely refluxing MEK. As for the state of the reaction liquid during the reaction, a slight increase in viscosity was observed as the reaction progressed, but there was no problem such as wrapping of the reaction liquid around the half-moon stirring blade, and the state of sufficient stirring was maintained. It was.

At the start of the reaction, 4.0 hours and 6.0 hours after the start of the reaction, a part (3 g) of the reaction solution was collected and cooled with ice to stop the reaction. Gel permeation chromatography (GPC) Method) and gas chromatography (GC method).
The GPC analysis was performed according to the following procedure. First, MEK 3 times as much as the reaction solution and 0.2 wt% potassium lactate aqueous solution were added to the reaction solution, dispersed, and then dissolved by heating. Subsequently, the pH of the aqueous phase was lowered to 4 or less with lactic acid, and the palmitic acid soap was changed to a fatty acid (palmitic acid) to extract and remove salts and sucrose into the aqueous phase. Further, the MEK phase was dried and GPC analysis was performed on the dried product (including SE and fatty acid). The results are shown in Table 1. From this result, the ester distribution of SE was examined.

平均置換度を、以下の式より算出した。
平均置換度=［ｍｏｎｏ置換体の量（ｗｔ％）×１＋ｄｉ置換体の量（ｗｔ％）×２＋ｔｒｉ置換体の量（ｗｔ％）×３＋ｔｅｔｒａ置換体の量（ｗｔ％）×４＋ｐｅｎｔａ置換体の量（ｗｔ％）×５］×０．０１

The average substitution degree was calculated from the following formula.
Average degree of substitution = [amount of mono substitution (wt%) × 1 + amount of di substitution (wt%) × 2 + amount of tri substitution (wt%) × 3 + amount of tetra substitution (wt%) × 4 + amount of penta substitution (Wt%) × 5] × 0.01

  GC analysis was performed by a trimethylsilylation method. For details of the trimethylsilylation method, refer to, for example, Introduction to Lipid Analysis, Japan Society Publication Center, P178-180, January 15, 1985; From this analysis result, the amounts of sucrose and fatty acids were quantified. Table 2 shows the analysis results of the reaction product by the GC method.

  The sample for GC analysis was prepared as follows. 50 mg of the reaction solution was precisely weighed, and 1 ml of a pyridine solution in which 5 mg / ml of squalane was dissolved was added as an internal standard, and dissolved by heating to 70 ° C. To this, 0.7 ml of 1,1,1,3,3,3-hexamethyldisilazane (1,1,1,3,3,3-hexamethyldesirazane) and 0.5 ml of trimethylchlorosilane (Trimethylchlorosilane) were added in this order. The mixture was stirred at 70 ° C. for 10 minutes and allowed to stand at room temperature, and 2 μl of the supernatant was subjected to GC analysis. Further, the amount of palmitic acid was measured by the GC method, and the amount of potassium salt was estimated as the amount of potassium palmitate.

以上の結果から、原料ＳＥと活性化ショ糖の反応が進行して、ＳＥの置換度が下がり、ＨＬＢ１５のＳＥが生成されたことが確認された。即ち、ＨＬＢ１５相当のＳＥを、反応液の高粘度化を特に問題にすることなく合成できた。

From the above results, it was confirmed that the reaction between the raw material SE and the activated sucrose progressed, the substitution degree of SE was lowered, and SE of HLB15 was produced. That is, SE corresponding to HLB15 could be synthesized without particularly raising the viscosity of the reaction solution.

  The produced SE had almost the same color as the raw material SE, and coloring by the reaction product was not recognized. The SE contained 1.0 ppm of MEK. The amount of Ash in the SE was 2.0% by weight.

Example 2
<Synthesis of raw material SE>
SE with an average degree of substitution (actually measured value) 2.11 and a ratio of constituent fatty acids; palmitic acid: stearic acid = 82: 18 was synthesized as follows.
DMSO 7000 g, sucrose 1320 g, fatty acid methyl ester (ratio of constituent fatty acids; palmitic acid: stearic acid = 82: 18) 1680 g and anhydrous potassium carbonate 25 g were added to the reactor, and 88-92 ° C. under a pressure of 2.67 kPa. While refluxing DMSO, the reaction was continued for 7.0 hours until 99% or more of the fatty acid methyl ester had reacted and disappeared. After completion of the reaction, a 50% by weight aqueous lactic acid solution was added to adjust the pH to 6.0. This liquid was supplied to an evaporator, and DMSO was evaporated at 90 ° C. under a pressure of 1.73 kPa. As a result of GC analysis of the obtained composition, it was 30% by weight of DMSO, 7% by weight of unreacted sucrose, 62% by weight of SE, and 1% by weight of other components.

  Add 3 parts by weight of isobutanol and 3 parts by weight of water (containing 2000 ppm of potassium lactate) to this composition, and perform extraction at 60 ° C under normal pressure to remove unreacted sucrose on the aqueous phase side. did. Furthermore, liquid-liquid extraction was performed at 60 ° C. under normal pressure using water (containing 2000 ppm of potassium lactate) for the isobutanol phase (upper phase) to remove DMSO. The isobutanol phase obtained by this extraction was supplied to a thin film evaporator, and isobutanol was removed to 2% by weight under 13.3 kPa. By adding water 3 times by weight to this and further evaporating and dehydrating, a sucrose fatty acid ester (ratio of constituent fatty acids; palmitic acid: stearic acid = 82: 18) having an average substitution degree (actual value) 2.11 Obtained.

<Reaction of raw material SE with activated sucrose>
Reaction and analysis under the same conditions as in Example 1, except that SE 5.0 g obtained by the above method, 35.9 g of white powder containing activated sucrose obtained in Example 1 and 27.2 g of MEK were used. Went. The reaction was stopped at 6.0 hours to obtain SE with an average degree of substitution of 1.26. The analysis results are shown in Tables 3 and 4 below. The degree of substitution and the amount of potassium palmitate were calculated in the same manner as in Example 1.

From the above results, it was confirmed that the reaction of SE obtained by the direct method with activated sucrose progressed, the substitution degree of SE was lowered, and SE of HLB15 was produced. That is, SE corresponding to HLB15 could be synthesized without particularly raising the viscosity of the reaction solution.
The produced SE had almost the same color as that of the raw material SE, and coloring by the reaction product was not recognized. The SE contained 1.0 ppm of MEK. The amount of Ash in the SE was 2.1% by weight.

Example 3
35.9 g of white powder containing activated sucrose used in Examples 1 and 2 and 5.0 g of SE having an average substitution degree of 2.11 and 75.8 g of toluene used in Example 2 were added to round bottom eggplant at room temperature. The flask was put into a mold flask. While the inside of the round bottom eggplant-shaped flask is in an N ₂ atmosphere, the reaction liquid in the flask is sufficiently stirred at 410 rpm using a motor-driven stirring blade (half moon type), and a 90 ° C. oil bath is used. And heated. In this state, the reaction was carried out at normal pressure for 9.0 hours while fully refluxing toluene. As the reaction progressed, a slight increase in the viscosity of the reaction solution was observed, but there was no problem such as wrapping of the reaction solution around the half-moon stirring blade, and the state where the reaction solution was sufficiently stirred was maintained. At the start of the reaction, the reaction solution 2.0 hours, 4.0 hours, 6.0 hours, and 9.0 hours after the start of the reaction was analyzed in the same manner as in Example 1. The measurement results are shown in Tables 5 and 6.

From the above results, it was confirmed that by using a solvent having a low relative dielectric constant, the reaction between SE and activated sucrose progressed, the substitution degree of SE decreased, and SE of HLB16 was produced. That is, a low substitution degree SE equivalent to HLB 16 could be synthesized without particularly raising the viscosity of the reaction solution.
The produced SE had almost the same color as the raw material SE, and coloring by the reaction product was not recognized. The SE contained 1.0 ppm of toluene. The amount of Ash in the SE was 2.3% by weight.

Example 4
The reaction was carried out under the same conditions as in Example 1 using SE with an average degree of substitution of 1.43 obtained by the direct method as a raw material. In addition, the unreacted activated sucrose after reaction was removed by water extraction, and MEK was removed by distillation. As a result, SE with an average substitution degree (actual measurement value) of 1.21 was obtained. The obtained low substitution degree SE contained 1.5 ppm of MEK. From the SE, no solvent other than the solvent used in the reaction of the method of the present invention (however, excluding water, MeOH and EtOH) was not detected. The amount of Ash in the SE was 2.5% by weight.

Example 5
SE 5.0 g having an average substitution degree of 2.11 used in Example 2, activated sucrose (100 g of sucrose and 2.35 g of KOH having a purity of 86% by weight, and a mixed solvent of 100 g of water and 100 g of ethanol were dissolved in 90 ° C. 11.5 g, MEK 27.2 g and stearic acid monoglyceride (“Emazol MP-V” manufactured by Riken Vitamin Co., Ltd.) 20.7 g It poured into the bottom eggplant type flask. While the inside of the round bottom eggplant-shaped flask is in an N ₂ atmosphere, the reaction liquid in the flask is sufficiently stirred at 200 rpm using a motorized stirring blade (half moon type), and an oil bath at 90 ° C. is used. And heated. In this state, the reaction was carried out at normal pressure for 6.0 hours while completely refluxing MEK. As for the state of the reaction liquid at the time of the reaction, there was no problem such as wrapping of the reaction liquid around the half-moon stirring blade, and a sufficiently stirrable state was maintained. The reaction solution after 6.0 hours was analyzed in the same manner as in Example 1. The average degree of substitution of SE after 4.0 hours reaction was 1.23. The amount of Ash in the SE was 0.8% by weight.

Comparative Example 1
12.4 g of sucrose (upper white sugar) crushed in a mortar, 13.1 g of SE with a substitution degree of 2.22 used in Example 1, 10.0 g of MEK, 4.5 g of potassium stearate and potassium carbonate (K ₂ CO ₃ ) 0.43 g was charged into a round bottom eggplant type flask at room temperature. While the inside of the round bottom eggplant-shaped flask is in an N ₂ atmosphere, the reaction liquid in the flask is sufficiently stirred at 410 rpm using a motor-driven stirring blade (half moon type), and a 90 ° C. oil bath is used. And heated. In this state, the reaction was carried out at normal pressure for 8.0 hours while fully refluxing toluene. The reaction solution at the start of the reaction and 8.0 hours after the start of the reaction was analyzed in the same manner as in Example 1. Table 7 shows the measurement results.

表７の結果で、反応により、ＳＥの置換度は若干上がっていた。このことから、ＳＥとショ糖を、本発明方法における溶媒存在下で反応させるには、ショ糖が活性化ショ糖である必要があることが明らかとなった。

As a result of Table 7, the substitution degree of SE was slightly increased by the reaction. From this, it became clear that sucrose must be activated sucrose in order to react SE with sucrose in the presence of the solvent in the method of the present invention.

Comparative Example 2
12.4 g of sucrose (upper white sugar) crushed in a mortar, 13.1 g of SE with a substitution degree of 2.22 used in Example 1, 18.5 g of MEK, 17.4 g of potassium palmitate and 0.42 g of potassium methoxide At normal temperature, it was put into a round bottom eggplant type flask. While the inside of the round bottom eggplant type flask is in an N ₂ atmosphere, the reaction liquid in the flask is sufficiently stirred at 410 rpm using a motor-driven stirring blade (half moon type), and an oil bath at 90 ° C. is used. And heated. In this state, the reaction was carried out at normal pressure for 6.0 hours while fully refluxing toluene. The reaction solution at the start of the reaction and 4.0 hours after the start of the reaction was analyzed by the same method as in Example 1. Table 8 shows the measurement results.
In addition, as a result of GC analysis, it was confirmed that a very small amount of fatty acid methyl ester was produced and a slight degree of substitution of SE was reduced, but the reaction of sucrose with SE as shown in Examples 1 to 4 Was not waking up. This also revealed that in order to react SE with sucrose in the presence of the solvent in the method of the present invention, sucrose must be activated sucrose.

Reference example
A comparison of the evaporation rates of MEK and DMSO was made. Specifically, sucrose fatty acid ester ("Ryoto Sugar Ester P1670" manufactured by Mitsubishi Chemical Foods, Inc., ratio of constituent fatty acids; palmitic acid: stearic acid = 82: 18, average degree of substitution (actual value) 1.21) 100 g and 5 g of MEK or DMSO were placed in a sample bottle. The sample bottle was stored in a sealed state for 7 days. SE5g containing DMSO or MEK was placed on a bottom of a 58 mmφ cylindrical aluminum cup so as to spread evenly and weighed. Six such aluminum cups were prepared and placed in a vacuum dryer (the outline of the apparatus is shown in FIG. 1) kept at 90 ° C., and the vacuum dryer was decompressed to 50 Torr (6.7 kPa). One sample was taken out every 1 hour after the start of decompression. Each sample was weighed and then ground in a mortar, and the residual amount of solvent was quantified by GC analysis. The results are shown in FIG. From this result, it was found that the solvent used in the method of the present invention can be easily removed because MEK clearly evaporates more easily than DMSO.

It is a figure which shows the outline | summary of the vacuum dryer used by the reference example. It is a graph which shows the comparison of the evaporation rate of MEK and DMSO.

Claims (15)

  A method for producing a sucrose fatty acid ester having a low substitution degree by reducing the degree of substitution of the raw sucrose fatty acid ester, wherein the raw sucrose fatty acid ester and the activated sucrose have a relative dielectric constant of 35.0 at 20 ° C. A process for producing a sucrose fatty acid ester having a low degree of substitution, wherein the reaction is carried out in the presence of a solvent which is the following and has no hydroxyl group.   The method according to claim 1, wherein a solvent having a relative dielectric constant of 1.1 to 20.0 at 20 ° C is used as the solvent.   A method for producing a low-substitution sucrose fatty acid ester by reducing the substitution degree of the raw sucrose fatty acid ester, wherein the raw sucrose fatty acid ester and the activated sucrose have a boiling point of 150 ° C. or less at normal pressure. A method for producing a low-substituted sucrose fatty acid ester, wherein the reaction is carried out in the presence of a solvent having a solubility in water at 20 ° C. of 50 g / 100 ml or less and having no hydroxyl group.   The average substitution degree of raw material sucrose fatty acid ester is reduced by 0.2 or more, The production method according to any one of claims 1 to 3.   The average substitution degree of the low-substituted sucrose fatty acid ester is 1.0 to 2.0, The production method according to any one of claims 1 to 4.   The average substitution degree of the low-substituted sucrose fatty acid ester is 1.0 to 1.6, The production method according to any one of claims 1 to 5, wherein   The average substitution degree of raw material sucrose fatty acid ester is 1.5-5.0, The manufacturing method as described in any one of Claims 1-6 characterized by the above-mentioned.   The production method according to any one of claims 1 to 7, wherein the raw sucrose fatty acid ester is an ester of a fatty acid having 8 to 22 carbon atoms. The production method according to claim 1, wherein the raw sucrose fatty acid ester is an ester of palmitic acid. The method according to any one of claims 1 to 8, wherein the reaction between the raw sucrose fatty acid ester and the activated sucrose is carried out in the presence of an emulsifier. A low-substituted sucrose fatty acid ester obtained by the production method according to claim 1. Low substitution sucrose fatty acid comprising an average degree of substitution of 1.0 to 1.6, a relative dielectric constant at 20 ° C. of 35.0 or less and a solvent [solvent (a)] having no hydroxyl group A low-substitution sucrose fatty acid ester which is an ester and does not contain a solvent other than the solvent (a) (excluding water, methanol and ethanol). The average degree of substitution is 1.0 to 1.6, the boiling point at normal pressure is 150 ° C. or lower, the solubility in water at 20 ° C. is 50 g / 100 ml or lower, and a solvent having no hydroxyl group [solvent (b )], A low-substituted sucrose fatty acid ester, which does not contain a solvent other than the solvent (b) (excluding water, methanol, and ethanol). Fatty acid ester. The sucrose fatty acid ester having a low degree of substitution according to claim 12 or 13, wherein the amount of Ash is 6.0% by weight or less. The low-substituted sucrose fatty acid ester according to any one of claims 11 to 14, wherein 70 to 100% of the fatty acid constituting the sucrose fatty acid ester is palmitic acid.

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