JP3610583B2 - Method for producing sucrose fatty acid ester powder - Google Patents

Description

【００１８】
注） ＩＢＡ：イソブチルアルコール
粉体状態
◎…サラサラで流動性改良
○…やや流動性に欠ける
×…流動性不良
【００１９】
【発明の効果】
本発明により、着色を抑え、出来上がりの粉末状態及び取扱い性の良い、粉砕工程等の後工程が不要であるＳＥ粉末が得られる。[0001]
[Industrial application fields]
The present invention relates to the production of sucrose fatty acid ester powder. Specifically, the present invention relates to a method for obtaining a sucrose fatty acid ester powder that is less colored and excellent in handleability by freeze-drying an aqueous solution of sucrose fatty acid ester.
In particular, the present invention relates to a method for obtaining sucrose fatty acid ester powder from an aqueous sucrose fatty acid ester solution without going through a grinding step.
[0002]
[Prior art]
Sucrose fatty acid ester (hereinafter abbreviated as SE) is formed by ester bonding of sucrose and fatty acid, and is used in various applications as a surfactant and an emulsifier. SE has various characteristics depending on the degree of ester substitution in the molecule and the number of carbon atoms of the constituent fatty acid.
[0003]
Usually, SE is produced by various methods based on the transesterification reaction between sucrose and a fatty acid lower alkyl ester. The crude SE obtained by this reaction is a mixture of mono, di, triester or higher polyester and contains unreacted sucrose. Thus, sucrose and organic acid salts are removed from crude SE by liquid-liquid extraction using water and an organic solvent. Since SE is obtained as an organic solvent solution by liquid-liquid extraction, it is usually concentrated by a thin film evaporator or the like and then subjected to steam distillation by adding water to remove the residual organic solvent to produce an SE aqueous solution. Next, this SE aqueous solution is concentrated to obtain solid SE. However, depending on the chain length of the constituent fatty acid and the presence or absence of a double bond, the SE aqueous solution becomes very easy to foam, and it may be very difficult to concentrate. Moreover, SE obtained from the final concentration step of the SE aqueous solution is in a paste state, and additional steps such as cooling / solidification and pulverization are necessary as post-steps.
[0004]
Recently, SE with high monoester purity has been commercialized. These are mainly used in the field of biochemical reagents, and are also used as emulsifiers for fragrances and pharmaceuticals (see Japanese Patent Laid-Open Nos. 61-247352 and 60-126230). SE used for these applications needs to have high purity, and may become unusable especially when the amount of colored substances (furan compounds or compounds having a double bond) increases. When an aqueous SE solution is processed with a general concentrator such as a thin-film evaporator or evaporator, the operability defects due to foaming and the increase of colored substances may become severe. This is not suitable as a method for producing SE.
[0005]
[Problems to be solved by the invention]
The present invention provides a method for directly recovering SE powder having good handleability while avoiding foaming and suppressing an increase in coloring substances when an aqueous SE solution is concentrated and dried.
[0006]
[Means for Solving the Problems]
The present inventors have found that an SE solvent can be obtained in which an organic solvent is present in an SE aqueous solution and freeze-dried to suppress an increase in coloring substances, and the finished powder state and product handleability are good. The present invention has been reached.
Hereinafter, the present invention will be described in detail.
[0007]
Any kind of raw material SE may be used in the present invention, and the constituent fatty acid and the production method thereof are arbitrary. The constituent fatty acid is preferably one or more of saturated and / or unsaturated fatty acids having 6 to 24 carbon atoms, preferably 8 to 22 carbon atoms. For example, caprylic acid, capric acid, lauric acid, palmitic acid, stearic acid, oleic acid, erucic acid and the like can be mentioned.
[0008]
The average degree of substitution of SE used as a raw material is arbitrary, but SE having a low average substitution degree and a short constituent chain length or a double bond is preferably used.
The concentration of the organic solvent present in the SE aqueous solution is preferably 0.1 to 20% by weight, particularly 2 to 10% by weight. The organic solvent is not particularly limited as long as it forms a homogeneous solution with water in the presence of SE. Usually, lower alcohols such as methanol, ethanol and isobutyl alcohol, esters such as acetic acid methyl ester and ethyl acetate, acetone, etc. And ketones such as methyl ethyl ketone, with lower alcohols being particularly preferred. If there is no organic solvent in the SE aqueous solution to be lyophilized, the finished powder state is not so good and the product is not easily handled because it is difficult to become porous. On the other hand, if the concentration of the organic solvent is too high, the frozen state during drying cannot be maintained and foaming occurs, making it difficult to obtain a sufficiently dried powder product.
[0009]
Moreover, as SE concentration in SE aqueous solution, 0.1 to 50 weight% normally, especially 1 to 30 weight% is preferable, and the residual organic solvent density | concentration in the powder product after drying becomes low, so that the weight% of water is high. There are advantages.
In the present invention, the SE aqueous solution containing the organic solvent as described above is dried by a freeze-drying method to recover SE powder. This freeze-drying can be carried out according to a known method.
[0010]
The freezing temperature of the SE aqueous solution is usually in the range of the freezing point to -180 ° C, preferably -10 to -90 ° C. There are no particular limitations on the freezing method and freezing state, for example, freezing with a refrigerator or refrigerant (dry ice-alcohol system), freezing in a bulk or thin film state, etc., anyway, freezing during freeze-drying It is desirable to maintain state. If the frozen state cannot be maintained, it returns to the aqueous solution and a rapid foaming phenomenon is observed. When foaming occurs, water sublimation or evaporation becomes insufficient, and it is difficult to obtain a sufficiently dry powder SE. The operating pressure during lyophilization is usually 0.01 to 20 Torr, particularly 0.1 to 5 Torr, and should be higher than the pressure at which the sample can be kept frozen. Heating during lyophilization increases the sublimation rate of water and improves productivity. However, if the heating temperature is too high, it may melt from the frozen state (return to an aqueous solution) and foaming may occur. is there. The heating temperature during freeze-drying is suitably 0 to 90 ° C, particularly 10 to 50 ° C. The heating method is arbitrary, and it is preferable to heat the sample stepwise or continuously at a constant temperature or a constant temperature while observing the frozen state of the sample.
[0011]
The water content of the powder SE obtained by freeze-drying of the present invention is usually 5% by weight or less, preferably 2% by weight or less, and the amount of organic solvent contained in the SE powder at this time is usually 100 ppm or less. It is. That is, the substantial total amount of the organic solvent present in the raw material SE aqueous solution is removed together with water, and hardly remains in the product. The SE powder recovered in the present invention is a powder having good fluidity and can be used as a product as it is.
[0012]
【Example】
EXAMPLES Next, although an Example demonstrates this invention further in detail, this invention is not restrict | limited by the following examples, unless the summary is exceeded.
[0013]
Examples 1-3
In a 250 ml beaker for pressure resistance, 15 g of a 10 wt% water-isobutyl alcohol solution of SE [brand name: SM-1200 (constituent fatty acid: 95 wt% lauric acid, 99% monoester, manufactured by Mitsubishi Kasei Foods Co., Ltd.)] The film was frozen in a dry ice-ethanol solvent. The refrigerant temperature was -71 ° C. In order to make the frozen state more complete, it was kept in dry ice-ethanol for about 30 minutes.
After freezing, the beaker was set in a Yamato Neocool (freeze dryer) previously maintained at a high vacuum of 3.5 Torr, and dried under vacuum for about 24 hours. The drying temperature was room temperature (23.5 ° C.). Further, no foaming phenomenon was observed during lyophilization. Note that, under this lyophilization condition, the frozen state cannot be maintained when isobutyl alcohol is at a high concentration (for example, 40% by weight).
[0014]
A certain amount of the freeze-dried powder SE was placed in a 10 ml volumetric flask and dissolved in tetrahydrofuran. The water concentration of this solution was measured by the Karl Fischer method. Further, as an index of the degree of coloring, the ultraviolet absorbance at 280 nm was measured with a 1% by weight aqueous solution. Residual isobutyl alcohol concentration was measured by an internal standard method by gas chromatography. The absorbance of the raw material SM-1200 used for the test is 0.035.
The results are shown in Table-1.
[0015]
Comparative Example 1
In the same manner as in Examples 1 to 3, lyophilization was performed using an aqueous sucrose fatty acid ester solution containing no isobutyl alcohol. The obtained product was slightly hygroscopic and not very dry. The results are shown in Table-1.
[0016]
Reference Examples 1-2
Using an aqueous solution having an IBA concentration of 0 or 10% by weight and a solid content concentration of SM-1200 of 10% by weight, concentration was performed using a rigid thin film evaporator manufactured by Tokyo Rika. The jacket temperature was 140 ° C. and the pressure was 40 to 45 Torr. When the IBA concentration was 0% by weight, concentration was impossible due to severe foaming. The results of Reference Examples 1 and 2 are shown in Table-1.
[0017]
[Table 1]

[0018]
Note) IBA: Isobutyl alcohol powder state ◎… Smooth fluidity improvement ○… Slightly lacking fluidity ×… Inferior fluidity [0019]
【The invention's effect】
According to the present invention, SE powder that suppresses coloring, has a finished powder state and good handleability, and does not require a subsequent step such as a pulverization step can be obtained.

Claims (5)

A method for producing a sucrose fatty acid ester powder, comprising freeze-drying an aqueous sucrose fatty acid ester solution containing an organic solvent. Sucrose in which a sucrose fatty acid ester having 6 to 24 carbon atoms in a constituent fatty acid is dissolved in water containing an organic solvent to form a uniform solution together with water and the organic solvent, and is lyophilized Method for producing fatty acid ester powder. Method for producing a sucrose fatty acid ester powder according to claim 1 or 2 concentration of organic solvents, characterized in that freeze-dried ones 0.1-20 wt%. Method for producing a sucrose fatty acid ester powder according to any one of claims 1 to 3 concentrations of tio sugar fatty acid ester is characterized by freeze-drying a thing of from 0.1 to 50% by weight.   The method for producing a sucrose fatty acid ester powder according to any one of claims 1 to 4, wherein the organic solvent is selected from the group consisting of lower alcohols, esters and ketones.