JPH0667951B2 - Method for producing powdery sucrose fatty acid ester - Google Patents

Description

Detailed Description of the Invention [Industrial applications]

The present invention relates to an industrial method for producing powdered sucrose fatty acid ester. More specifically, the present invention relates to a method for industrially producing powdery high-quality sucrose fatty acid ester without using an organic solvent for purification.

[Prior art]

(Background) Currently, sucrose fatty acid ester (hereinafter abbreviated as << SE >>) useful as a surfactant is industrially used as sucrose and C _{8 to} C _22.
With higher fatty acid methyl ester of sucrose in a solvent (dimethylformamide, dimethylsulfoxide, etc.) under an appropriate catalyst (solvent method: JP-B-35-13102), or using sucrose with water without a solvent. It is obtained by making a molten mixture with soap and then reacting it with a higher fatty acid methyl ester in the presence of a catalyst (water medium method: JP-B-51-14485). However, in addition to the target SE, unreacted sugar,
It contains impurities such as unreacted fatty acid methyl ester, residual catalyst, soap, free fatty acid, and volatile matter. Impurities of which the content exceeds the specified amount must be removed before it becomes a product. I have to. In particular, the removal of residual solvent (volatile matter) from the above-mentioned contaminants by the latter solvent method is
It is very important only to the _Note) that off-the-shelf is have become stricter recently. Note) According to US FDA standards, the residual dimethyl sulfoxide allowed in SE is 2 ppm or less (Fed. Regist., 51 (2
14), 40160-1). By the way, the purification means which has been conventionally used for the purification of SE through the above-mentioned methods is the use of a solvent, but the use of this solvent brings many industrial disadvantages as described below. Risk of explosion and fire. Explosion-proof electrical equipment provided above. Sealing the manufacturing equipment in preparation for the above. Fireproof structure of the entire building in preparation for the above. Fixed cost increase due to above. Cost increase due to solvent loss. Negative effect of residual solvent remaining in product SE. The negative impact on the health of employees, and the resulting increase in the number of units increases the cost. Under such circumstances, the development of a purification technique that makes it unnecessary to use a purification solvent during SE purification has been an urgent need in the industry. (Problems of the prior art) Therefore, a purification method that does not use an organic solvent has been conventionally studied. For example, as a typical method, (1) a method for precipitating SE with an acidic aqueous solution (UK Patent 809,815 (1)
959)) (2) Precipitation method of SE with general neutral salt solution (Japanese Patent Publication No. 42-88).
50) etc. are known. However, as in the method (1), for example, when an aqueous hydrochloric acid solution is added to the reaction mixture, the more SE is precipitated, the unreacted sucrose is easily decomposed and converted into glucose and fructose,
Even if carried out at low temperature (0 to 5 ° C), decomposition cannot be avoided. Therefore, it becomes difficult to recover and reuse the unreacted sugar. Further, as in the method (2), SE is immediately precipitated even if an aqueous solution of a neutral salt such as sodium chloride and salt cake is added to the reaction mixture. In this case, decomposition of unreacted sugar does not occur, but monoester, which is a useful component in SE, dissolves in the aqueous phase side, so not only does it cause a large loss, but especially high HLB of which there is much demand in recent years. It is an obstacle when you want to get SE. Further, according to the more recent JP-A-51-29417, a mixed solution of water and a "purification solvent" (particularly called so as to distinguish from a reaction solvent) has a light liquid layer (upper layer) and a heavy liquid layer (lower layer). The property of phase separation is used. That is, since the heavy liquid layer (lower layer) generally contains a large amount of water, hydrophilic unreacted sugars, salts derived from catalysts, etc. are dissolved in this heavy liquid layer (lower layer). On the other hand, the light liquid layer (upper layer) contains a large amount of purified solvent, so S
E, fatty acids, unreacted fatty acid methyl esters, etc. having a small polarity are dissolved in this light liquid layer. However, reaction solvents such as dimethylsulfoxide also dissolve in the lower heavy liquid layer, but unfortunately they also dissolve in the upper light liquid layer, making it impossible to completely separate the reaction solvent by this method alone. Is. Therefore, a very large amount of purified solvent is required only for the purpose of removing a very small amount of reaction solvent. Thus, in order to industrially enable the purification of crude SE with water, it is a major premise to develop a purification method in which the solvent is completely removed and the sugar and the product SE are not lost. Next, what must be considered in order to industrially enable purification with water is the water content associated with using water as a purification solvent.
It is a means of drying SE. That is, the water-containing SE to be dried here usually has a water content of 80
% Or more is usually in the form of an aqueous solution, and water less than 80% is usually in the form of a slurry. The water content of these SEs generally shows a sharp increase in viscosity from around 40 ° C and reaches the maximum value around 50 ° C, but when the temperature exceeds 50 ° C, the viscosity decreases sharply, exhibiting a very unique viscous behavior. (Sugar Ester Story) 108
page). Besides, it is practically impossible to simply evaporate the water by heating under vacuum because of the remarkable foaming property. If the heating temperature is high and the contact time with the heating element is long, SE causes decomposition, which not only causes strong coloring and caramelization, but also the acid value of fatty acids released by decomposition. Also rises (Japanese Patent Publication Sho 37-996
See 6). Especially at the end of water evaporation, due to the characteristic of SE having a low softening point or melting point (for example, the softening point of sucrose monostearate is around 52 ° C, and the melting point of sucrose distearate is around 110 ° C). It has a tendency to hydrate the remaining water, which makes dehydration extremely difficult. In addition, the latent heat of vaporization of water is abnormally high (500K
cal / Kg · H ₂ O or more) and high evaporation temperature are factors that make drying difficult. Therefore, for example, as another type of drying method, even when using a so-called flash type dryer that heats sludge and continuously supplies it to the vacuum chamber and discharges it, due to the large latent heat of water, it is sufficient. Various difficulties are associated with dehydration and drying,
Even if you can overcome these difficulties, SE after dehydration and drying under vacuum is in a molten state, so after taking it out from the dryer, cool it by blowing cold air etc. to the melting point or less, It requires many steps of solidifying and finally crushing with a crusher, and there is a concern of dust explosion in the final crushing step. Therefore, solving the various problems associated with the drying as described above is also an important step for realizing the purification by the aqueous medium method.

[Problems to be Solved by the Invention]

In view of the above circumstances, the present invention is a crude product synthesized by a solvent method.
In the purification of SE, regardless of the use of a purified solvent, by developing a purification method that does not cause substantial loss of SE and a drying method that does not cause quality deterioration in the drying process, it is possible to reduce The purpose is to solve the problem. (Concept of the invention) Therefore, the present inventor not only suppresses (a) the amount of SE dissolved in the water phase side to the minimum,
Many are aimed at solving the three problems of separating SE from SE by precipitating SE, (b) avoiding decomposition of unreacted sugar, and (c) dissolving the remaining reaction solvent outside the aqueous phase. As a result of conducting a salting-out experiment of, when sucrose and a neutral salt were dissolved in an aqueous solution of a reaction mixture, under appropriate combination of pH, temperature, concentration of neutral salt and sucrose, and water amount,
It was found that not only the total amount of SE precipitates, but surprisingly, a reaction solvent other than unreacted sugar is dissolved in the aqueous phase, which is a convenient phenomenon. Therefore, by utilizing this phenomenon, the precipitated SE is redissolved in water again, and the precipitation operation with a neutral salt and an aqueous sucrose solution is repeated to effectively prevent the loss of SE, while remaining residual volatiles ( Remaining reaction solvent) can be completely transferred into the aqueous phase, and the neutral salts and sucrose accompanying the precipitated SE can be washed with acidic water having an appropriate pH. To give a purified SE which is substantially removed by;
Also, it was revealed that the powdery SE can be continuously produced by spray-drying the slurry of SE precipitated above without any quality deterioration. (Outline) The present invention is based on the above discovery, and in addition to the objective sucrose fatty acid ester, a reaction mixture containing unreacted sugar, unreacted fatty acid methyl ester, catalyst, soap, fatty acid and volatile matter, Precipitate generated by adding water, neutral salt and sucrose to a pH in the neutral range is washed with acidic water, neutralized, spray-dried and then spray-dried. The gist is a method for producing a sugar fatty acid ester. Hereinafter, various matters related to the invention will be explained. (Synthesis of SE by Solvent Method) In the synthesis of SE by the solvent method, usually, a mixture of sucrose and fatty acid methyl ester is added to and dissolved in a reaction solvent several times the total amount thereof, for example, dimethyl sulfoxide. Then, in the presence of an alkaline catalyst such as potassium carbonate (K ₂ CO ₃ ), the reaction rate of 90% or more (based on fatty acid methyl ester) can be easily maintained by maintaining the temperature at 80 to 90 ° C. for about several hours in the vacuum of 20 to 30 Torr. An SE reaction mixture is produced at. Next, in order to eliminate the activity of the alkaline catalyst in the SE reaction mixture, an equivalent amount of an organic acid such as lactic acid or acetic acid or a mineral acid such as hydrochloric acid or sulfuric acid is added to the SE reaction composition. By this neutralization, the catalyst is converted into a potassium salt such as potassium lactate. Finally, the reaction solvent becomes a composition (reaction mixture after neutralization and distillation) in the following composition range when dimethyl sulfoxide is distilled off under vacuum, for example. Sucrose fatty acid ester = 15-92% Unreacted sugar = 1.0-80% Unreacted fatty acid methyl ester = 0.5-10% Neutral salt derived from potassium carbonate = 0.05-7% Soap = 1.0-10% Fatty acid = 0.5-10 % Volatile matter (remaining reaction solvent) = 5.0-30% At this time, the ester distribution of SE is 10-75% of monoester.
(90% to 25% of diester or more). The fatty acid root mainly contained in each of the fatty acid methyl ester, soap and fatty acid is saturated and has a common C _{16 to} C ₂₂ carbon number. (Water) Next, water is added to the above reaction mixture so that the ratio of water: reaction mixture = 5: 1 to 40: 1 (weight ratio) (1), more preferably, water: Reaction mixture = 20: 1 (weight ratio) ... Add to the ratio of formula (2) and adjust the pH to 6.2 to 8.2, preferably pH 7.5. In this case, the water addition ratio is out of the above range, for example,
When the amount ratio of water to the reaction mixture is less than 5, the viscosity of the obtained aqueous solution becomes large, and the subsequent operation becomes substantially difficult. On the contrary, when an excess amount of water is added such that the amount ratio of water to the reaction mixture exceeds 40, the viscosity becomes small and the subsequent operation becomes easy, and the reaction solvent of interest is Although the removal is also suitably performed, on the other hand, a great energy cost is required to remove the water when recovering the unreacted sugar and the like, and the economical efficiency is lost. Furthermore, the pH of the aqueous solution is preferably adjusted to pH 6.2 to 8.2 in order to avoid the decomposition of the target SE. pH 8.2
Under the above hydrogen ion concentration, the quantitative
There is a concern that SE may be decomposed, and even in a weakly acidic range of pH 6.2 or lower, if exposed to a high temperature of 90 ° C or higher, for example, there is a risk of acid decomposition. (Salting out) The aqueous solution of the SE reaction mixture whose pH has been adjusted as described above is kept at 50 to 80 ° C as much as possible, and a neutral salt and sucrose are further added. In this case, the neutral salt to be added preferably first satisfies the following formula (3). Here, total salt amount = neutral salt amount to be added + salt amount formed from catalyst …… (4) Total sugar amount = sucrose amount to be added + unreacted sugar amount from the beginning …… (5) Next The amount of sucrose to be added should be determined by the following formula (6). Further, in addition to the above two formulas, it is preferable that the weight ratio of the total salt amount and the total sugar amount also satisfies the following formula (7). The present inventors have prepared an aqueous solution containing a precipitate of SE obtained by adding a neutral salt and sucrose so as to satisfy all of the above formulas (3), (6) and (7) up to 50 to 80 ° C. It was found that even if the composition of volatile matter (remaining reaction solvent) contained in the SE reaction mixture fluctuates significantly to 5.0 to 30.0% when heated and heated, almost all SE precipitates approximately. It was This phenomenon is a unique phenomenon and has important value for the purpose of the invention. The attached FIG. 1 is a ternary graph showing this phenomenon in more detail. In this figure, the weight of SE dissolved in the water phase = Y [g], the weight of precipitated SE = X [g], the total SE (X + Y) [g], the water phase side If the weight ratio of SE dissolved in φ = φ [%], φ is defined by the following equation (8). Here, the following conditions: temperature = 80 ° C., pH = 7.5, water: reaction mixture = 7.4: 1 (weight ratio) fatty acid residue = stearic acid composition of reaction mixture sucrose fatty acid ester = 29% unreacted sugar = 35 % Unreacted fatty acid methyl ester = 2% Catalyst-derived salt = 1% Soap = 3% Fatty acid = 1% Volatile content (remaining reaction solvent) = 29% Distribution of ester in SE: monoester = 73% Diester or more = 27 In%, how the value of φ changes is shown by triangular coordinates. Here, the total salt is the amount defined by the formula (4) and the total sugar is the amount defined by the formula (5), respectively, and is shown as water amount + total salt amount + total sugar amount = 100%. The shaded area in FIG. 1 is the expression found by the inventors.
It is a region that simultaneously satisfies (3), formula (6), and formula (7). By determining the amounts of neutral salt and sucrose that fall within the shaded area, it is possible to precipitate substantially SE = 0, that is, approximately the total amount of SE can be precipitated, and the precipitated SE can be collected by filtration. Alternatively, by centrifugation, it is possible to completely separate from the volatile matter dissolved in the aqueous phase side (remaining reaction mixture) (that is, to completely remove the contaminating volatile matter). (Washing) After the above salting-out operation, pH = 3.0 to 5.5, temperature was adjusted to about 10 to 40 ° C., and the above-mentioned separation was performed using temperature-controlled acidic water.
Wash the SE cake. Suitable acids used for this purpose are, for example, mineral acids such as hydrochloric acid and sulfuric acid, and organic acids such as acetic acid and lactic acid, but are not limited to those exemplified. By washing under such conditions, desired impurities can be transferred to the water phase side while minimizing the amount of SE redissolved from the cake side to the water phase side. In the above washing operation, if the temperature of the acidic water reaches 40 ° C or higher, if the operation takes a long time, for example, several months, SE
Not only is there concern over acid decomposition, but the viscosity increases and operation becomes difficult. On the other hand, in order to maintain a low temperature of 10 ° C or lower, it is necessary to install a refrigerator that is economically neglected. Therefore, it is usually preferable to operate at 10 to 40 ° C, especially near room temperature. When washing the SE cake with this acidic water, the volatile components (reaction solvent) contained in the cake, unreacted sugar, added neutral salts and salts by-produced by neutralization of the catalyst Since it is necessary to remove the four components from the SE cake as much as possible, it is desirable that the SE cake be chopped in the acidic water to have a particle size as small as possible. This object can be efficiently achieved by a subdivision device such as a dispersion mixer (for example, "Homomixer" manufactured by Tokushu Kiki Kogyo Co., Ltd.), a homogenizer or a colloid mill (for example, trade name "Mycolloyder"), and volatile matter (Reaction solvent), unreacted sugar, catalyst-derived salt, and neutral salt are all transferred from the precipitated SE cake to the acidic aqueous phase, although the amount is substantially small. It is inevitable that some SE will elute in the acidic aqueous phase.The tendency of dissolution in acidic water is stronger for SE with higher monoester content, so increase the diester and triester content relatively. The above-mentioned washing of the SE cake with acidic water becomes more complete by increasing the number of washings and the amount of washing water, and thus it is possible to obtain purified SE that is virtually pure. The water-containing SE purified in this way is sludge-like (slurry), but as it is, the pH is biased toward the acidic side, so the slurry adjusted to have a pH near neutral is
It does not contain unreacted sugar, catalyst-origin salt, volatile matter and sucrose and neutral salts added during salting out, but contains SE, unreacted fatty acid methyl ester, soap and fatty acid. It is often in the range of 1 to 50% and water content of 99 to 50%. The amount of solids in this slurry is roughly the
It is preferably 40% or less, but an excessively small solid content ratio is not desirable from the viewpoint of energy cost for drying, and a value of 4% or more is usually economical. (Spray Drying) In the present invention, a spray drying method is particularly used for drying SE slurry. The usefulness of this drying means is the most suitable method for the dehydration drying of SE sludge having a solid content of 40 to 96% found by the present inventor by many experimental facts. Incidentally, as described above, also in the case of using an ordinary vacuum dryer represented by a so-called groove-type stirring dryer, the sludge is continuously supplied and heated to be discharged into the vacuum chamber. Even when using a so-called flash dryer, it is not possible to avoid deterioration of quality such as acid value increase, coloring, caramelization, etc. of SE to be treated due to the viscosity characteristics and low melting point of SE. Moreover, in the latter case, the danger of dust explosion cannot be ignored. However, by adopting the spray drying means found by the inventor, the drawbacks of the past drying means can be solved all at once. In the drying step in the present invention, sucrose-containing sucrose fatty acid ester in a sludge state is continuously supplied to a spray drying tower via a pump, and atomized into fine atomized particles by spraying with a nozzle or centrifugal force of a rotating disk (disk). Divide into pieces and contact with a dry air stream. This significantly increases the evaporation area of water, which is extremely short (within a few seconds after spraying).
Then dehydration and drying can be completed. As the atomizing means, it is preferable to use a rotating disk because the hydrous sucrose fatty acid ester has a high viscosity. (Spray drying conditions) The supply temperature of the sucrose fatty acid ester solution or slurry is 40 ~
The temperature can be changed arbitrarily between 80 ° C, but from the viewpoint of quality, it is desirable to select a temperature within the range of 40 to 60 ° C. When the above solution or sludge is atomized by a rotating disc, for example, when the disc diameter is 5 to 10 cmφ, 15,000 to 24,000
The rpm is suitable. The air blown into the tower should possess more than the amount of heat required to evaporate the water in the solution or sludge, and thus a higher amount of air is needed at lower air temperatures.
The air temperature at this time may be in a wide range of 10 to 100 ° C, but it is advantageous to select the temperature between 60 to 80 ° C in consideration of the drying efficiency and the thermal decomposition prevention of the target sucrose fatty acid ester. is there. The humidity in the blown air is also related to the drying efficiency together with the air temperature. Absolute humidity suitable for work is roughly , But especially It is economical to be in the range of. When the solid content concentration in the slurry sent to the spray drying tower exceeds 40%, the viscosity is remarkably increased, and as a result, the particle size of the sprayed slurry becomes relatively large, and the drying of water is delayed accordingly, resulting in As a result, it easily adheres to the inner wall of the drying tower. Therefore, it is preferable to adjust the solid content concentration in the slurry to 40% or less. When the solid content concentration of the slurry is 40% or less, the sprayed liquid droplets are smaller than when they are more than 40%, and are easily dried, so that there is no fear of adhering to the inner wall of the drying tower. However, when the solid content concentration of the slurry becomes small, for example, less than 3%, drying becomes easy, but it is uneconomical in terms of required energy. Therefore, the slurry supply concentration to the spray drying tower is 4
A range of% -40% is suitable. Various conditions such as required volume, required tower height and required height of the spray drying tower are designed on the premise of the above spraying conditions. If the tower design and working conditions are appropriate, powdered dry sucrose fatty acid ester having a water content of 5% or less is continuously discharged from the lower part of the spray drying tower. The obtained product has a short heat history, so that it is extremely excellent in quality and requires almost no personnel for the drying operation.

[Action]

Acid is added to the sucrose fatty acid ester formation reaction mixture containing unreacted sugar, unreacted fatty acid methyl ester, catalyst, soap, fatty acid and volatile matter (remaining reaction solvent) to adjust the pH to a neutral range, then water. When salting out at an appropriate temperature with the addition of a neutral salt and sucrose, sucrose fatty acid ester, unreacted fatty acid methyl ester, soap and fatty acid precipitate, and volatile matter (remaining reaction solvent) remains in the aqueous phase. Since it moves to the side, residual volatile components can be removed without using any organic solvent. In particular, by operating so as to satisfy the conditions of formula (2), formula (6), and formula (7), it is possible to remove the residual solvent with substantially no loss of SE. Next, the precipitate is washed with acidic water to remove impurities such as volatile components contaminated during the precipitation, unreacted sugar, added neutral salt and salt by-produced by neutralization of the catalyst. , Becomes a slurry of purified SE. By spray-drying this refined slurry, powdery SE having a water content of 5% or less is continuously produced.

【Example】

Hereinafter, modes and effects of the invention will be described in Examples and Comparative Examples, but the examples are, of course, for the purpose of explanation, and are not intended to limit or limit the inventive idea. Example 1 A dry product obtained by neutralizing the residual liquid obtained by distilling the reaction solvent from the solvent method SE reaction mixture represented by the composition in Table 1 below with lactic acid, and then drying.
2,000 g of water was added to 0 g and dissolved. 62.5 g of sucrose and 97.6% of 50% potassium lactate were added to this aqueous solution.
g was added, the temperature was raised to 75 ° C., the temperature was raised, and the precipitated cake was filtered off to obtain a cake having a solid content of 53%. In addition, in the filtrate
SE was virtually not included. When 2,000 g of room temperature hydrochloric acid (pH 3.5) was added to the above cake, SE immediately precipitated as a white precipitate. Next, the acidic aqueous solution (pH 3.5) containing this precipitate was thoroughly stirred with a homomixer (manufactured by Tokushu Kiki Kogyo Co., Ltd.), and the precipitate was collected by filtration. To this precipitate, after performing twice the operation of re-washing by adding hydrochloric acid again, the purified cake obtained by adjusting the pH to 7.5 with caustic soda was 150.8 g in total and contained 25% solids, The dried product had the composition shown in Table 2 below. The washing liquid (filtrate) contained a small amount of SE. This slurry was supplied to a pilot spray drying tower while being kept at 50 ° C., and spray dried. Drying conditions are as follows: Diameter of spray drying tower: 20.mφ Length of straight cylinder: 1.5m Air flow: Rotating disk diameter = 10cmφ Disk rotation speed = 24,000rpm Inlet air temperature = 60 ° C, Inlet air absolute humidity: Slurry supply rate: Met. The powdered SE obtained from the bottom of the spray-drying tower has a water content of 1.81
%, The bulk specific gravity was 0.41, and there was no coloring due to overheating, and the fluidity was good. The drying could be continued stably, and there were no worries at first, such as the powder adhering to the inner wall of the spray drying tower. The amount of monoester in SE was 68% before and after the drying, and there was no change in the acid value. Example-2 While maintaining the 25% solids precipitation cake (slurry) obtained in Example-1 at a temperature of 50 ° C., the inlet air temperature was 40%.
Spray drying was carried out in the same manner as in the same example except that the slurry supply rate was changed to 0.5 kg / hour. The SE powder thus obtained had a water content of 1.92%, a bulk specific gravity of 0.42, good flowability and no coloring due to overheating. The amount of monoester in SE was 68%, which was the same before and after drying, and the acid value was the same. Furthermore, no SE powder adhered to the inner wall of the spray drying tower was observed.

【The invention's effect】

As described above, the present invention has developed a series of techniques for industrially producing a powdered purified sucrose fatty acid ester from a crude sucrose fatty acid ester reaction mixture without using a purifying organic solvent. As a result, the following great effects are achieved. (1) SE can be purified using only inexpensive water. (2) Since SE can be dried under normal pressure within a short time, there is no heat deterioration of the product. (3) There is no risk of solvent explosion or fire, and therefore no expensive explosion-proof electrical equipment is required. (4) There is no concern that the purification solvent will be mixed into the product. (5) Improving the hygienic environment of the workplace. (6) It can be industrialized at low cost.

[Brief description of drawings]

FIG. 1 is a triangular graph showing the relationship between changes in the amounts of water, total sugar and total salt and the amount of sucrose fatty acid ester dissolved in the aqueous phase.

Claims (16)

[Claims] 1. In addition to the desired sucrose fatty acid ester, unreacted sugar, unreacted fatty acid methyl ester, catalyst, soap,
The reaction mixture containing fatty acids and volatiles should be adjusted to pH in the neutral range and water, neutral salts and sucrose should be added to wash the precipitate, which was washed with acidic water, neutralized, and then spray dried. A method for producing a powdery sucrose fatty acid ester, comprising: 2. The composition of the reaction mixture is such that unreacted sucrose = 1.0 to 80.0% unreacted fatty acid methyl ester = 0.5 to 10.0% catalyst = 0.05 to 7.0% soap = 1.0 to 10.0% fatty acid = 0.5 to 10.0% The method according to claim 1, wherein volatile matter (remaining reaction solvent) = 3.0 to 50.0%. 3. The method according to claim 1, wherein the reaction mixture is adjusted to pH 6.2-8.2. 4. The method according to claim 1, wherein the reaction mixture after pH adjustment is heated to 50 to 80 ° C. 5. The weight ratio of water added to the reaction mixture to the reaction mixture is water: reaction mixture = 5: 1 to 40: 1.
The method described. 6. The method according to claim 1, wherein the neutral salt and sucrose are added to the reaction mixture according to the following relational expression. And, And, Here, total salt amount = neutral base to be added + salt amount produced by neutralization of catalyst Total sugar amount = sucrose amount to be added + unreacted sugar amount from the beginning 7. The acid used to adjust the pH of the reaction mixture comprises:
The method according to claim 1 or 3, wherein the acid is any one selected from the group consisting of lactic acid, acetic acid, hydrochloric acid and sulfuric acid. 8. The fatty acid root mainly contained in each of the fatty acid methyl ester, soap and fatty acid in the reaction mixture has a common saturated fatty acid root having 16 to 22 carbon atoms.
The method described. 9. The method according to claim 1, wherein the component of the volatile matter (remaining reaction solvent) in the reaction mixture is dimethyl sulfoxide or dimethylformamide. 10. The method according to claim 1 or 6, wherein the neutral salt added to the reaction mixture is any salt selected from the group consisting of sodium chloride, mirabilite, potassium lactate and potassium acetate. 11. The method according to claim 1, 2 or 6, wherein the ester distribution of the sucrose fatty acid ester is 10 to 75% (90 to 25% of diester or more) as a monoester content. 12. The method according to claim 1, wherein the pH value of the acidic water is 3.0 to 5.5. 13. The method according to claim 1, wherein the temperature of the acidic water is 10 to 40 ° C. 14. Slurry of sediment to be spray dried.
Is a solid content = 4-40% and water content = 96-60%. 15. The humidity and temperature of the blast air during spray drying are The method of claim 1, wherein the method is within the range. 16. The method according to claim 1, wherein the composition of the powdery sucrose fatty acid ester of the product is within the following range. Moisture = 0.5-5.0% Unreacted fatty acid methyl ester = 0.5-10.0% Soap = 0.5-60.0% Fatty acid = 0.5-10.0% Sucrose fatty acid ester = 98.0-15.0%