JP3168695B2 - Method for lowering substitution degree of sucrose fatty acid ester - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION
An object of the present invention is to provide a method for reducing the degree of substitution of sucrose fatty acid ester using sucrose fatty acid ester as a part of the raw material. More specifically, the present invention provides a method for reducing the degree of substitution of a sucrose fatty acid ester, which has a high reaction rate of sucrose, has no coloring, and is easily purified.

[0002]

2. Description of the Related Art Sucrose fatty acid esters (hereinafter abbreviated as SE) are obtained by esterifying sucrose and a fatty acid, and vary depending on the degree of substitution of hydroxyl groups in the sucrose molecule and the number of carbon atoms of the fatty acid. It is possible to manufacture SE having various HLB values and characteristics. Its main uses include food emulsifiers, foaming agents, bacteriostats and the like. SE production methods can be broadly classified into a solvent method and a solventless method. As a feature of the solvent method, it is possible to produce SE under relatively mild conditions, and there are few by-products due to decomposition of sucrose. On the other hand, although the solventless method has the convenience of using no solvent, it reacts at a high temperature (130 to 160 ° C.) from the beginning of the reaction with a large amount of sucrose, and there are also many decomposition products of raw materials such as sucrose. SE
The yield is poor and the product is severely colored. In particular, in the production of SE with a low degree of substitution, it is necessary to use a large excess of sucrose,
Coloring due to the decomposition of sucrose is even more pronounced.

Conventionally, there has been known a method for producing SE having characteristics different from that of the raw material SE by using SE as a part of the raw material by a solventless method.
00. The specification discloses a method of heating and melting SE, soap, and sucrose to produce SE having a higher HLB value (that is, low substitution degree) than the raw material SE. In this method, it is said that the raw material SE should have an HLB value of 3 or more, preferably an HLB value of 5 to 12. Specifically, SE having an HLB value of 10.5 or 7.0 is used as a raw material. The HLB value is 14.0 or 1 respectively.
We produce 0.5 SE. Sucrose fatty acid ester having an HLB value of less than 3 (average degree of substitution is approximately 3 to 8)
) Was not known at all.

In general, in the solventless method, soap used as a reaction aid has a large carbon number and a large amount of soap. For example, in the above-mentioned JP-A-59-78200,
Although soaps having 16 and 18 carbon atoms are used in the examples, the larger the carbon number, the lower the solubility in water, and the more difficult it is to remove by a simple method such as liquid-liquid extraction. In addition, as for the amount of soap, the above specification describes that it is better that the amount used is relatively large, and that the amount is 100 to 150% by weight based on the raw material SE. However, it is difficult to remove soap having a large carbon number, which is disadvantageous in cost and operation on an industrial scale.

As a recent technique, various purification methods have been devised to solve these problems, but they have not been satisfactory yet. For example, in order to reduce the alkali metal ion level to less than 1 ppm, there has been proposed a method of treating with a strongly alkaline aqueous solution and removing soap with a centrifugal separator (Japanese Patent Laid-Open Nos. 1-2207296 and 1-2159).
4). However, fatty acid esters, particularly sucrose fatty acid esters, are stable near neutrality, but are liable to undergo ester hydrolysis on the alkaline and acidic sides. Further, in the molecule of sucrose, a caramelization reaction or the like occurs due to a hydroxyl group elimination reaction or the like, and a furan-based compound (furfural, furfuryl alcohol, or the like), which is one of coloring substances, is easily generated. In addition, a decoloring step or the like is required as a separate step, which is very disadvantageous in cost and operation on an industrial scale.

[0006]

DISCLOSURE OF THE INVENTION The present invention makes it possible to produce SE by a solvent-free method using SE having an average degree of substitution of 3 to 8 as a raw material, facilitates the removal of soap, and causes problems such as coloring. It is an object of the present invention to provide a method for lowering the degree of substitution of SE than that of the raw material SE without causing the above.

[0007]

Means for Solving the Problems The present inventors have made intensive studies in view of the above-mentioned circumstances, and as a result, have found that it is possible to reduce the degree of substitution of SE using SE having an average degree of substitution of 3 to 8 as a raw material. The inventors have found that the difficulty of removing soap can be overcome and arrived at the present invention. That is, the gist of the present invention is that, in the presence of an alkali catalyst and soap, the average degree of substitution is 3 to 3.
8. A method for reducing the degree of substitution of sucrose fatty acid ester, which comprises melting sucrose fatty acid ester A and sucrose or sucrose fatty acid ester B having a lower degree of substitution than sucrose fatty acid ester A by heating. Exist.

Hereinafter, the present invention will be described in detail. The raw material SE used in the present invention, that is, sucrose fatty acid ester A (hereinafter abbreviated as “SE-A”; the same applies to B and C) and SE-B may be of any type, and the constituent fatty acids and the production thereof The constituent fatty acid has a saturated and / or saturated carbon number of usually 6 to 24, preferably 12 to 22.
Or one or more unsaturated fatty acids, such as lauric acid, myristic acid, palmitic acid, stearic acid, oleic acid, and erucic acid.

The average degree of substitution of SE-A is usually 3 to 8, preferably 4 to 8 (typically 0 to 3 when represented by HLB value).
Preferably it is equivalent to 0-2). Specific examples of SE-A include S-170 (where the constituent fatty acid is stearic acid 7).
0% by weight, palmitic acid 30% by weight; average degree of substitution5.
2) and P-170 (constituent fatty acid is 70% by weight of palmitic acid, 30% by weight of stearic acid; average degree of substitution 5.3) and the like (all are manufactured by Mitsubishi Chemical Corporation (currently Mitsubishi Chemical Corporation)).

The average degree of substitution of SE-B is not particularly limited as long as it is lower than SE-A, but it is usually 0.1 to 2, preferably 1 to 1.7 (the HLB value is usually 5
To 20, preferably 8 to 17). Specific examples of SE-B include P-1670 (constituent fatty acid is 70% by weight of palmitic acid, stearic acid is 30% by weight).
Weight percent; average degree of substitution 1.3) and S-1170 (constituent fatty acids 70% by weight of stearic acid, palmitic acid 30% by weight; average degree of substitution 1.6). ) Co., Ltd.).

The amounts of SE-A and sucrose or SE-B to be used are not particularly limited, and may be varied depending on the desired average substitution degree of SE-C.
For example, the used amount of SE-A is determined by the total charged amount (SE-A, S
EB, sucrose, soap, total amount of catalyst)
% By weight, preferably 30 to 85% by weight, more preferably 5% by weight.
The amount of sucrose or SE-B is 1 to 90% by weight, preferably 10 to 60% by weight. When the heat-melting reaction is performed at a low temperature (110 ° C. or lower), the viscosity of the reaction solution tends to increase.
Is preferably larger than the amount of sucrose or SE-B used. Also, rather than using sucrose,
The use of B can keep the viscosity of the reaction solution low.

The alkali as a catalyst includes a hydroxide, a carbonate, or a sodium methoxide of an alkali metal such as potassium hydroxide, sodium hydroxide, lithium hydroxide, potassium carbonate, sodium carbonate, and lithium carbonate.
It is appropriately selected from alkali metal alkoxides such as sodium ethoxide and potassium methoxide. The charged molar ratio of the catalyst to sucrose or SE-B is 0.01 to 1, preferably 0.1 to 0.5, based on sucrose or SE-B. The form of charging the catalyst is not particularly limited, and the catalyst may be supplied after being dissolved in powder or water or alcohol. For example, catalyst, sucrose or SE
-B, soap and the like are preferably dissolved uniformly in water and / or lower alcohol, and then dried under reduced pressure to form an activated product, which is then preferably used for heating and melting.

The charging conditions for activation include water and / or lower alcohol and a catalyst, sucrose or SE-
B and the amount of soap added are not particularly limited, and the method of charging is not particularly limited. As the lower alcohol, a solvent that can be arbitrarily mixed with water is preferable, and for example, a short-chain alcohol such as methyl alcohol, ethyl alcohol, and butyl alcohol is preferable. The amount of water and / or lower alcohol is preferably adjusted so that the mixture is completely and uniformly dissolved. The conditions for drying by distilling off water and / or lower alcohol are as follows.
0-100 ° C., preferably 40-80 ° C.,
It may be performed under atmospheric pressure or reduced pressure. More preferably, in order to completely remove water, vacuum drying (1 Torr)
r or less, an internal temperature of 40 to 80 ° C.). The apparatus to be used is not particularly limited, and a spray dryer or the like generally used for drying powder is also suitable.

The soap is not particularly limited, but is preferably an alkali metal salt or an alkaline earth metal salt of a carboxylic acid having 2 to 10 carbon atoms, and more preferably a carboxylate having 3 to 8 carbon atoms. . The amount added to the reaction system is 0.1 to 90% by weight, preferably 1 to 50% by weight, based on SE-A. The amount of soap is usually 1 to 30% by weight, preferably 3 to 15% by weight, based on all the reactants. The form to which soap is added may be supplied by dissolving in powder or water and / or lower alcohol.
Preferably as described above, sucrose or SE-
After uniformly dissolving B, the catalyst and the soap in water and / or a lower alcohol, the solvent is preferably distilled off, dried and used as an activating substance. Further, the type and amount of soap used have a great relationship with the HLB value of SE-A and its amount, and the HLB value of sucrose or SE-B and its amount. For example, when heating and melting using SE-A having an HLB value of 1 and sucrose, the preferred soap and its amount are potassium caproate (C6), and
-A gives 10 to 20% by weight. Also, SE-A is H
In the case of heating and melting using an LB value of 2 and sucrose, the soap suitable for emulsification is potassium butyrate (carbon number 4) or potassium propionate (carbon number 3), the amount of which is relative to SE. -A gives 5 to 10% by weight. This is because the higher the HLB value (the more hydrophilic) of the whole reaction system, the more preferable the short-chain soap which is more hydrophilic, and the amount thereof tends to decrease as the chain becomes shorter.

The heating and melting temperature is usually 50 to 140.
C, preferably 80 to 110C. The pressure is
Usually 0.01 to atmospheric pressure, preferably 0.1 to 500 to
rr is appropriate. The apparatus is not particularly limited, but a commonly used stirring tank type apparatus, a kneader or an extruder used for highly viscous apparatuses are suitable. The order of adding the raw materials is not particularly limited, but preferably, SE-A is first heated to a predetermined temperature and melted by heating, and then sucrose or SE-B is added and stirred. In addition, when charging sucrose or SE-B, it is better to use a pulverized powder which is as pulverized as possible, so that the mixture with SE-A is uniform and quickly heated and melted. The heating and melting time is usually 0.5 to 8 hours, preferably about 1 to 4 hours.

Although there is no particular limitation on the method of post-treatment of the produced SE-C, generally used liquid-liquid extraction is suitable. After the completion of the reaction, in order to deactivate the catalyst, after adding various organic acids (for example, lactic acid, acetic acid, succinic acid, etc.), an organic solvent and / or water are added to the reaction mixture, and liquid-liquid extraction is performed. The organic solvent used is not particularly limited, and is not particularly limited as long as the solvent can dissolve SE.
Preferably, lower alcohols such as isopropyl alcohol and isobutyl alcohol are suitable. On this stair,
The short-chain soap used in the reaction dissolves in the aqueous layer and is removed, so that the concentration of the soap mixed into the product is extremely low. Further, the recovered soap can be reused as a reaction aid, and has a great merit in terms of cost.

[0017]

EXAMPLES Next, the present invention will be described in more detail with reference to examples, but the scope of the present invention is not limited by the following examples unless it exceeds the gist.
In the examples, as for the residual sucrose in the reaction product, the reaction product was sampled, dissolved in dimethylformamide, and sucrose was converted into a trimethylsilylated derivative, and then quantified by gas chromatography. For the SE in the reaction product, the reaction product was sampled, tetrahydrofuran was added, and the insoluble material was filtered off, and then analyzed by gel filtration chromatography and reversed-phase high-performance liquid chromatography.

Example 1 (Pretreatment, activation) In a 1 L round bottom flask equipped with a stirrer, 47.4 g of sucrose and potassium hydroxide as a catalyst were added.
83 g, potassium caproate (carbon number 6) as soap
After adding 19.7 g, 50 g of water and 300 g of methanol were added.
Was added and uniformly dissolved. The temperature inside the flask is 55-60
After the solvent was distilled off by nitrogen stripping while maintaining the temperature at 0 ° C., vacuum drying (0.1 Torr or less) was performed for 4 hours to obtain an adduct of fine powder.

(Heat-melting reaction) S- as a raw material (SE-A)
170 (sucrose stearate, average degree of substitution 5.
2. 120 g of Mitsubishi Kasei (currently Mitsubishi Chemical Co., Ltd.) was charged and reacted at 100 ° C.-1 Torr for 3 hours (the amount of soap used was 10.4% of the total reactants).

When the obtained highly viscous reactant was analyzed, the sucrose reaction rate calculated from the residual sucrose concentration was 6%.
4.1%, the yield of SE (S
E weight%) was 76.9% and the average degree of substitution was 2.5. The results are shown in Table 1 below. (Purification of SE) After completion of the above reaction, 10 parts of the reaction product was neutralized with lactic acid, dissolved in a mixed solvent of 90 parts of isobutyl alcohol and 100 parts of water, and stirred at 60 ° C for 10 minutes. After standing for 15 minutes, the isobutyl alcohol layer containing SE was separated from the aqueous layer containing unreacted sucrose, soap and the like, and the isobutyl alcohol layer was concentrated under reduced pressure, whereby purified SE as a white solid was obtained. It was recovered almost quantitatively.

At this time, when the potassium ion concentration was determined by titration, the total amount of potassium ions in the reaction product was 6.78 mmol, the total amount of potassium ions in the purified SE was 0.59 mmol, and the potassium ion removal rate Was 91.3%.

Examples 2 to 7 The same procedures as in Example 1 were carried out except that the type of soap was changed as shown in Table 1 below. Table 1 shows the results together with Example 1.
It was shown to. Examples 8 to 9 The same procedures as in Example 2 were carried out except that the amount of soap used was changed as shown in Table 2 below. The results are shown in Table 2 below together with Example 2. Examples 10 to 12 The same procedure as in Example 1 was carried out except that the pretreatment methods for sucrose, alkali catalyst and soap were changed as follows. The results are shown in Table 3 below together with Example 1.

(Pretreatment, Example 10) Only sucrose and soap were uniformly dissolved and vacuum dried, and potassium carbonate (K ₂ CO ₃ ) was added as a catalyst as a powder. The amount of the catalyst was モ ル mole of the potassium hydroxide (KOH) used in Example 1. (Pretreatment, Example 11) was fed with all the sucrose and soap and potassium carbonate (K ₂ CO ₃₎ powder. No activation processing. (Pretreatment, Example 12) Sucrose and potassium hydroxide (K
OH) was uniformly dissolved and vacuum dried, and soap was added as a powder.

Examples 13 and 14 The same procedure as in Example 7 was carried out except that SEs having different degrees of substitution were used as raw materials (SE-A). The results are shown in Table 4 below together with Example 8. Example 15 A reaction was carried out in the same manner as in Example 1 except that potassium stearate in the same molar amount was used instead of potassium caproate as the soap (the amount of soap used was the total amount of the reactants). 19.6%). When the obtained reaction solution was analyzed, the sucrose reaction rate was 45.6% and the SE yield was 6
The degree of substitution was 8.1% and the average degree of substitution was 3.0. Example 1
The reaction solution was subjected to liquid-liquid extraction in the same manner as described above, and purified SE as a white solid was almost quantitatively obtained. At this time, the total amount of potassium ions in the reaction solution was 6.08 mmol, the total amount of potassium ions in the purified SE was 3.44 mmol, and the removal rate of potassium ions was 43.4%.

Example 16 S-1670 (sucrose monostearate, average degree of substitution 1.3, average substitution degree 1.3 as sucrose as SE-B) in place of sucrose as a raw material, Mitsubishi Kasei (current Mitsubishi Chemical) Co., Ltd. Made)
Example 11 was performed except that was used. In the total amount of SE-A and SE-B before the reaction, the SE with a degree of substitution of 2 to 4 was 39% of the total SE, but the SE in the reactant contained all of the SE with a degree of substitution of 2 to 4. It increased to 72% of SE. The average degree of substitution of SE in the reaction product was 3.2.

Comparative Example 1 S having an average degree of substitution of 2.2 (corresponding to an HLB value of 3) as a raw material
Except using E, it carried out similarly to Example 8. When the reaction mixture was analyzed, the sucrose reaction rate was 9.3%, the yield of SE was 65.6%, and the average degree of substitution was 2. based on the residual sucrose concentration.
0, which was much less efficient than that of Example 8. In addition, since the reaction mixture is uniform and sticky from the beginning of the reaction and has a high viscosity, the stirring is rate-determined in a usual stirring tank, and it is difficult to carry out the reaction.

When Examples 1 to 16 and Comparative Example 1 are taken together,
In the method of the present invention, it has been found that the degree of substitution of SE is reduced by using an SE having an average degree of substitution of 3 to 8, which was not known before. In addition, even if the amount of soap used is small, the reaction is smooth and it can be said that it is preferable from the viewpoint of the ability to separate soap. According to the method of the present invention, a conventionally known SE having a low average degree of substitution was used as a raw material (Comparative Example 1), but the sucrose reaction rate and the yield of SE were significantly higher than those of Example 8. In this case, the operation of the stirring tank was difficult.

[0028]

According to the present invention, SE can be produced by a solvent-free method using SE having an average degree of substitution of 3 to 8 as a raw material, and at the same time, soap can be easily removed and adverse effects such as coloring can be prevented. A method of reducing the degree of substitution of SE without accompanying is provided.

[0029]

[Table 1]

[0030]

[Table 2]

[0031]

[Table 3]

[0032]

[Table 4]

Claims (2)

(57) [Claims] A sucrose fatty acid ester A having an average degree of substitution of 3 to 8 and sucrose or a sucrose fatty acid ester B having a lower degree of substitution than sucrose fatty acid ester A in the presence of an alkali catalyst and soap. And a method of reducing the degree of substitution of the sucrose fatty acid ester by heating and melting. 2. Sucrose, an alkali catalyst and soap are dissolved in water or a lower alcohol, and then dried to obtain a sucrose activating substance, which is a sucrose fatty acid ester A having an average degree of substitution of 3 to 8. And reducing the degree of substitution of the sucrose fatty acid ester by heating and melting.