JPH05178878A - Production of sucrose ester of fatty acid having low substitution degree - Google Patents

Abstract

PURPOSE:To obtain the subject ester, capable of being readily purified and having a high rate of reaction of sucrose without any coloring under substantially solventless conditions by thermally melting two kinds of sucrose esters of fatty acids in the presence of an alkaline catalyst and a soap. CONSTITUTION:For example, (A) a sucrose ester of a fatty acid having 3-8 (preferably 4-8) average substitution degree and (B) a sucrose ester having a lower substitution degree (preferably 1-1.7) than that of the component (A) are melted in the presence of an alkaline catalyst and a soap preferably at 80-110 deg.C under 0.1-500Torr to afford the objective ester.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention is
A method for producing a low-substituted sucrose fatty acid ester using sucrose fatty acid ester as a part of a raw material. More specifically, the present invention provides a method for producing a low-substituted sucrose fatty acid ester which has a high reaction rate of sucrose, is not colored, and is easily purified.

[0002]

BACKGROUND OF THE INVENTION Sucrose fatty acid ester (hereinafter abbreviated as SE) is formed by ester bond of sucrose and fatty acid, and varies depending on the substitution degree of hydroxyl group in the sucrose molecule and the carbon number of fatty acid. It is possible to manufacture SE having various HLB values and characteristics. Its main uses include food-grade emulsifiers, foaming agents, and bacteriostats. SE manufacturing methods can be broadly classified into a solvent method and a solventless method. A feature of the solvent method is that it is possible to produce SE under relatively mild conditions, and there are few by-products due to the decomposition of sucrose. On the other hand, although the solvent-free method has the advantage of not using a 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, which are SE
The yield is poor and the product is highly colored. Especially in the production of low-substituted SE, it is necessary to use a large excess of sucrose,
Coloring due to the decomposition of sucrose becomes more remarkable.

Conventionally, there has been known a method of producing SE having a characteristic different from that of the raw material SE by using SE as a part of the raw material by a solventless method. For example, JP-A-59-782.
00 is mentioned. The specification discloses a method for producing SE having a higher HLB value (that is, a lower degree of substitution) by heating and melting SE, soap, and sucrose. In this method, the raw material SE is said to have an HLB value of 3 or more, preferably an HLB value of 5 to 12, and specifically, an SE having an HLB value of 10.5 or 7.0 is used as the raw material. As the HLB value is 14.0 or 1 respectively
It produces 0.5 SE. No method has been known for producing a low-substitution SE from a high-substitution sucrose fatty acid ester having an HLB value of less than 3 (mean substitution is approximately 3 to 8).

In general, in the solventless method, soap used as a reaction aid has a large number of carbon atoms and a large amount thereof. 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. Moreover, regarding the amount of soap, it is described in the above specification that the amount used is preferably relatively large, and is preferably 100 to 150% by weight with respect to the raw material SE. However, it is difficult to remove soap with a large number of carbon atoms, which is disadvantageous in terms of cost and operation on an industrial scale.

As a recent technique, various purification methods have been devised in order to solve these problems, but they are still unsatisfactory. For example, in order to reduce the level of alkali metal ions to less than 1 ppm, a method of treating with a strong alkaline aqueous solution and removing soap with a centrifuge has been proposed (JP-A-1-207296, 1-211159).
4). However, a fatty acid ester, particularly a sucrose fatty acid ester, is stable in the vicinity of neutrality, but hydrolysis of the ester is likely to occur 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 compound (furfural, furfuryl alcohol, etc.), which is one of the coloring substances, is easily generated. Therefore, a decoloring step or the like is required as a separate step, which is very disadvantageous in terms of cost and operation on an industrial scale.

[0006]

DISCLOSURE OF THE INVENTION The present invention enables the production of low-substituted SE by a solventless method using SE having an average degree of substitution of 3 to 8 as a raw material, and facilitates the removal of soap.
In addition, S that is different from the raw material SE without any adverse effects such as coloring
It is intended to provide a method for producing E.

[0007]

Means for Solving the Problems As a result of intensive studies in view of the above circumstances, the present inventors have found that SE having an average degree of substitution of 3 to 8 can be used as a raw material to produce a low degree of substitution SE, Further, they have found that the difficulty of removing soap is overcome, and thus reached 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
8. Sucrose fatty acid ester A of 8 and sucrose or sucrose fatty acid ester B having a degree of substitution lower than that of sucrose fatty acid A are heated and melted to produce a low degree of substitution sucrose fatty acid ester C. Exist in.

The present invention will be described in detail below. 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 their production. The method is not limited, and the constituent fatty acid has a carbon number of usually 6 to 24, preferably 12 to 22 and / or saturated.
Alternatively, it is one or more of unsaturated fatty acids, and examples thereof include lauric acid, myristic acid, palmitic acid, stearic acid, oleic acid, and erucic acid.

The average substitution degree of SE-A is usually 3 to 8, preferably 4 to 8 (when expressed by an HLB value, usually 0 to 3,
It is preferably equivalent to 0 to 2). As a specific example of SE-A, S-170 (the constituent fatty acid is stearic acid 7
0% by weight, palmitic acid 30% by weight; average degree of substitution 5.
2) and P-170 (constituent fatty acids: 70% by weight of palmitic acid, 30% by weight of stearic acid; average substitution degree: 5.3) and the like (all manufactured by Mitsubishi Kasei Co., Ltd.).

The average degree of substitution of SE-B is not particularly limited as long as it is lower than that of SE-A, but is usually 0.1 to 2, preferably 1 to 1.7 (the HLB value is usually 5
~ 20, preferably 8 to 17) are used. As a specific example of SE-B, P-1670 (constituent fatty acid: 70% by weight of palmitic acid, 30% of stearic acid)
% By weight; average degree of substitution 1.3), S-1170 (70% by weight of stearic acid as constituent fatty acid, 30% by weight of palmitic acid; average degree of substitution 1.6) and the like (all manufactured by Mitsubishi Kasei Co., Ltd.). ..

The amount of SE-A and sucrose or SE-B used is not particularly limited, and the amount of each charge may be changed depending on the target average degree of substitution of SE-C.
For example, the amount of SE-A used is the total amount (SE-A, S
EB, sucrose, soap, total amount of catalyst) 10-90
% By weight, preferably 30 to 85% by weight, more preferably 5
The amount of sucrose or SE-B used is 1 to 90% by weight, preferably 10 to 60% by weight. Further, when the heat-melting reaction is carried out at a low temperature (110 ° C. or lower), the viscosity of the reaction liquid tends to increase, so SE-A
It is preferable to use more than the amount of sucrose or SE-B. Also, rather than using sucrose, SE-
The use of B can keep the viscosity of the reaction liquid low.

Alkali as a catalyst is a hydroxide, carbonate or sodium methoxide of an alkali metal such as potassium hydroxide, sodium hydroxide, lithium hydroxide, potassium carbonate, sodium carbonate or lithium carbonate.
It is appropriately selected from alkali metal alkoxides such as sodium ethoxide and potassium methoxide. The molar ratio of the catalyst and sucrose or SE-B charged is 0.01 to 1, preferably 0.1 to 0.5, relative to sucrose or SE-B. Further, the catalyst charging form 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
It is preferable to dissolve -B, soap and the like in water and / or lower alcohol uniformly and then dry under reduced pressure to obtain an activated product, which is then used for heating and melting.

As the charging conditions for activation, water and / or lower alcohol and catalyst, sucrose or SE-
There are no particular restrictions on the amount of B and soap added, and the method of preparation is also 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 above mixture is completely and uniformly dissolved. The conditions for distilling off water and / or lower alcohol and drying are usually at an internal temperature of 2
0 to 100 ° C, preferably 40 to 80 ° C is suitable,
It may be performed under atmospheric pressure or reduced pressure. More preferably, in order to completely distill off water, vacuum drying (1 Torr
r or less, internal temperature 40 to 80 ° C.). The device 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 alkaline earth metal salt of a carboxylic acid having 2 to 10 carbon atoms, more preferably a carboxylic acid salt 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 soap may be added in the form of powder or dissolved in water and / or lower alcohol and supplied.
Preferably, as mentioned above, sucrose or SE-
It is preferable that B, the catalyst and soap are uniformly dissolved in water and / or lower alcohol, and then the solvent is distilled off and dried to be used as an activating substance. Further, the type and amount of soap used are greatly related to the HLB value of SE-A and its amount, and the HLB value of sucrose or SE-B and its amount. For example, in the case of heating and melting SE-A having an HLB value of 1 and sucrose, the preferred soap and its amount are potassium caproate (carbon number 6),
-A is 10 to 20% by weight. H as SE-A
When heat-melting with an LB value of 2 and sucrose, a suitable soap for emulsification is potassium butyrate (carbon number 4) or potassium propionate (carbon number 3), the amount of which is relative to SE. -A is 5 to 10% by weight. This is because the higher the HLB value of the entire reaction system (more hydrophilic), the more hydrophilic short chain soap is preferable, and the amount thereof tends to decrease as the chain becomes shorter.

The heating and melting temperature is usually 50 to 140.
℃, preferably 80-110 ℃ is good. Also, the pressure is
Usually 0.01 to atmospheric pressure, preferably 0.1 to 500 to
rr is suitable. The apparatus is not particularly limited, but a generally used stirring tank type, a kneader, an extruder or the like used for a highly viscous one is suitable. The order of addition of the raw materials is not particularly limited, but it is preferable that SE-A is first heated to a predetermined temperature and melted by heating, and then sucrose or SE-B is added and stirred. Further, when sucrose or SE-B is charged, it is better to use a finely pulverized product as crushed as possible, so that the mixture with SE-A is uniform and is quickly melted by heating. The heating and melting time is usually 0.5 to 8 hours, preferably about 1 to 4 hours.

The method of post-treatment of the SE-C produced is not particularly limited, but liquid-liquid extraction generally used is suitable. After the completion of the reaction, various organic acids (eg, lactic acid, acetic acid, succinic acid, etc.) are added to deactivate the catalyst, and then an organic solvent and / or water is added to the reaction mixture to perform liquid-liquid extraction. The organic solvent used is not particularly limited and is not particularly limited as long as it can dissolve SE.
Lower alcohols such as isopropyl alcohol and isobutyl alcohol are preferably suitable. On this stairs,
The short chain soap used in the reaction dissolves in the aqueous layer and is removed, so that the concentration of soap in the product is extremely low. In addition, the recovered soap can be reused as a reaction aid and has a great cost advantage.

[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 as long as the gist thereof is not exceeded.
In the examples, the residual sucrose in the reaction product was sampled, dissolved in dimethylformamide, sucrose was converted to a trimethylsilylated derivative, and then quantified by gas chromatography. In addition, regarding SE in the reaction product, the reaction product was sampled, tetrahydrofuran was added to separate insoluble matter by filtration, and then analysis was performed by gel filtration chromatography and reverse 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 1.
83 g, potassium caproate as soap (6 carbon atoms)
After adding 19.7 g, 50 g of water and 300 g of methanol
Was added and dissolved uniformly. Flask internal temperature 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 a fine powder adduct.

(Heating / melting reaction) As a raw material (SE-A), 120 g of S-170 (highly substituted sucrose stearate, average substitution degree: 5.2, manufactured by Mitsubishi Kasei Co., Ltd.) was charged, and 100 ° C.-1 Torr. Reacted for 3 hours under the conditions of
(The amount of soap used corresponds to 10.4% of the total reaction).

When the obtained highly viscous reaction product was analyzed, the sucrose reaction rate calculated from the residual sucrose concentration was 6
4.1%, yield of SE (S in the total reaction mixture
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) 10 parts of the reaction product after completion of the above reaction 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, etc., and the isobutyl alcohol layer was concentrated under reduced pressure to obtain purified SE as a white dry solid. It was recovered almost quantitatively.

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

Examples 2 to 7 The same procedure as in Example 1 was carried out except that the type of soap was changed as shown in Table 1 below. The results are shown in Table 1 below together with Example 1.
It was shown to. Examples 8 to 9 The same procedure as in Example 2 was repeated 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 method for sucrose, alkali catalyst and soap was 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 in powder form. The catalyst amount was 1/2 mol of the potassium hydroxide (KOH) used in Example 1. (Pretreatment, Example 11) Sucrose, soap and potassium carbonate (K ₂ CO ₃ ) were all supplied in powder form. No activation treatment. (Pretreatment, Example 12) Sucrose and potassium hydroxide (K
Only OH) was uniformly dissolved and vacuum dried, and soap was added as a powder.

Examples 13 to 14 The same procedure as in Example 7 was carried out except that SE having different substitution degree was used as the raw material (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 the same molar amount of potassium stearate was used as the soap, instead of potassium caproate, as the soap. Corresponding to 19.6%). When the obtained reaction liquid 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. In addition, Example 1
The reaction solution was subjected to liquid-liquid extraction in the same manner as in, to obtain purified SE as a white dry solid almost quantitatively. 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 substitution degree 1.3, manufactured by Mitsubishi Kasei Co., Ltd.) having the same weight as sucrose was used as SE-B instead of sucrose as a raw material. Except for this, the same procedure as in Example 11 was performed. SE-A and S before reaction
In the total amount of EB, SE having a substitution degree of 2 to 4 is the whole SE
However, in the SE in the reaction product, the SE having a substitution degree of 2 to 4 increased to 72% of the total SE. The average degree of substitution of SE in the reaction product is 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
Example 8 was repeated except that E was used. When the reaction mixture was analyzed, the sucrose reaction rate was 9.3% based on the residual sucrose concentration, the SE yield was 65.6%, and the average substitution degree was 2.
It was 0, which was much less efficient than that of Example 8. Further, since the reaction mixture has a uniform sticky form from the early stage of the reaction and has a high viscosity, it is difficult to carry out the reaction because the stirring is rate-controlled in an ordinary stirring tank.

Combining Examples 1 to 16 and Comparative Example 1,
In the method of the present invention, SE having a high degree of substitution (average degree of substitution 3 to 8), which has not been heretofore known, is used as a raw material, and a low degree of substitution S
It was found that E was produced. Further, the reaction is satisfactory even when the amount of soap used is small, and it can be said that it is also preferable from the viewpoint of the separation ability of 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 SE yield were significantly higher than those in Example 8. It was also lower, and the operation of the stirring tank was difficult.

[0028]

EFFECTS OF THE INVENTION According to the present invention, SE having an average substitution degree of 3 to 8 can be used as a raw material for the production of SE by a solventless method, removal of soap can be facilitated, and adverse effects such as coloring can be prevented. An uncomplicated manufacturing method is provided.

[0029]

[Table 1]

[0030]

[Table 2]

[0031]

[Table 3]

[0032]

[Table 4]

Claims (2)

[Claims] 1. A sucrose fatty acid ester A having an average degree of substitution of 3 to 8 and a sucrose fatty acid ester B having a degree of substitution lower than that of sucrose fatty acid ester A in the presence of an alkali catalyst and soap. A method for producing a low-substituted sucrose fatty acid ester C, which comprises heating and melting. 2. A sucrose, an alkali catalyst and a soap,
A low-substituted sucrose fatty acid characterized by being dissolved in water or a lower alcohol and then dried to give a sucrose activator, which is heat-melted with sucrose fatty acid ester A having an average degree of substitution of 3-8. Method for producing ester C.