JPS6410518B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for decolorizing and purifying sugar fatty acid esters. More specifically, it relates to a method of decolorizing the crude sugar fatty acid ester and decomposing the fatty acid ester by treating a crude sugar fatty acid ester containing at least fatty acid esters as impurities with hydrogen peroxide and a lipolytic enzyme. be.

Sugar fatty acid esters have high biodegradability and safety, so they have recently been used as surfactants to fundamentally solve environmental pollution and toxicity problems for living organisms, and have been used as additives in foods, cosmetics, pharmaceuticals, resins, etc. agent,
It is an extremely useful compound that is being developed for a wide range of uses, including laundry detergents, kitchen detergents, shampoos, and other detergents.

Various methods are known for producing sugar fatty acid esters, and among them, the most common method is alcoholysis of sugar and fatty acid ester in the presence of a base catalyst.

The crude sugar fatty acid ester produced by this method is inevitably colored due to the thermal decomposition of the sugar, fatty acid ester, and product during alcoholysis, as in the case of other methods.

Therefore, it is desirable to decolorize the crude sugar fatty acid ester by an appropriate method, but at present, there is almost no known method for decolorizing crude sugar fatty acid esters in an industrially advantageous manner.

In addition, the crude sugar fatty acid ester contains, in addition to the desired sugar fatty acid ester, by-products such as soaps and alcohols, unreacted substances such as sugar and fatty acid esters,
Furthermore, it contains impurities such as unreacted base catalyst and/or decomposed products of the base catalyst, and it is necessary to remove these impurities by an appropriate method and purify the sugar fatty acid ester.

Among these impurities, substances other than fatty acid esters can be removed relatively easily and almost completely by appropriately combining various operations such as neutralization, conversion to other derivatives, filtration, extraction, and crystallization. However, fatty acid esters have chemical properties such as reactivity and physical properties such as solubility in solvents. Because they are very similar to fatty acid polyesters, it is impossible to selectively decompose only fatty acid esters into fatty acids and alcohols, which can be easily separated and removed, using pure chemical methods. Attempts to remove fatty acid esters more completely using physical methods have the major drawback of not being able to avoid the loss of a considerable amount of sugar fatty acid esters.

The first object of the present invention is to provide a method for effectively and industrially advantageous decolorization of crude sugar fatty acid esters.

A second object of the present invention is to provide a method for selectively decomposing only fatty acid esters in crude sugar fatty acid esters into fatty acids and alcohols that can be easily separated and removed.

As a result of various studies aimed at achieving the above object, the present inventors have found that an aqueous solution or aqueous suspension of a crude sugar fatty acid ester containing at least fatty acid esters as an impurity is treated with hydrogen peroxide and lipid decomposition. It was discovered that crude sugar fatty acid esters can be decolorized and fatty acid esters can be decomposed by treatment with enzymes, leading to the completion of the present invention.

Next, the present invention will be explained in detail.

Sugar fatty acid esters to which the present invention is applied include arabinose, xylose, ribose, glycol (glucose), mannose, galactose,
Fructose, maltose, cellobiose, trehalose, gentiobiose,
Isomaltose, lactose (milk sugar), sucrose (sucrose), raffinose, gentianose,
Monosaccharides, disaccharides, trisaccharides, tetrasaccharides, or polysaccharides such as maltotriose, stachyose, xylan, alaban, cellulose, starch, etc. and carbon atoms of 6 to 24
All sugar fatty acid esters that are esters with fatty acids and have one or more ester bonds in the same molecule are included. In particular, sucrose fatty acid ester is one of the sugar fatty acid esters most suitable for the present invention in terms of ease of production and wide range of uses.

The fatty acid esters contained as impurities include glycerin fatty acid esters, fatty acid esters of aliphatic lower monohydric alcohols, fatty acid esters of aliphatic lower dihydric alcohols, carbitol fatty acid esters, and the like.

To explain fatty acid esters more specifically,
The glycerin fatty acid ester is an ester of glycerin and a fatty acid having 6 to 24 carbon atoms, and may be any one of a glycerin monofatty acid ester, a glycerin difatty acid ester, or a glycerin trifatty acid ester.

Furthermore, the fatty acid ester of an aliphatic lower monohydric alcohol refers to an ester of methanol, ethanol, propanol, butanol, etc., and a fatty acid having 6 to 24 carbon atoms.

Furthermore, the fatty acid ester of aliphatic lower dihydric alcohol refers to an ester of ethylene glycol, propylene glycol, butanediol, diethylene glycol, etc. and a fatty acid having 6 to 24 carbon atoms, and may be either a monoester or a diester.

Furthermore, carbitol fatty acid esters include carbitol, that is, diethylene glycol monoalkyl ether, more specifically carbitol such as diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monopropyl ether, and diethylene glycol monobutyl ether, and carbon atoms of 6 to 24. Refers to esters with fatty acids.

In addition to the above-mentioned sugar fatty acid esters and fatty acid esters as impurities, the crude sugar fatty acid esters to which the present invention is applied include soaps such as sodium soap, potassium soap, amine soap, and calcium soap. There is no problem in containing alcohols and salts such as sugars, fatty acids, glycerin, aliphatic lower monohydric alcohols, aliphatic lower dihydric alcohols, carbitol, etc., and at least the above-mentioned sugar fatty acid esters and fatty acid esters. Crude sugar fatty acid esters containing the following are applicable to the present invention, regardless of the manufacturing method, history, content of each component, etc. In particular, the reaction product obtained by the alcoholysis method of sugar and fatty acid ester in the presence of a base catalyst is one of the crude sugar fatty acid esters to which the present invention can be most suitably applied.

Although various methods can be adopted to treat an aqueous solution or suspension of a crude sugar fatty acid ester with hydrogen peroxide and a lipolytic enzyme, it is usually possible to treat the crude sugar fatty acid ester as it is. , or some or all of the coexisting soaps, sugars, fatty acids, alcohols, salts, etc., are removed in advance according to known methods, and then water is added to dissolve or suspend them in water to create an aqueous solution. A method for simultaneously decolorizing crude sugar fatty acid esters and decomposing fatty acid esters by preparing a solution or an aqueous suspension and then adding hydrogen peroxide and a lipolytic enzyme, an aqueous solution,
Alternatively, after preparing an aqueous suspension, add a lipolytic enzyme to previously decompose some, most, or all of the fatty acid esters, and then add hydrogen peroxide to decolorize the crude sugar fatty acid ester and decolorize the fatty acid ester. After preparing an aqueous solution or suspension, hydrogen peroxide is added to decolorize the crude sugar fatty acid ester to some extent, and a lipolytic enzyme is added to continue further processing. , or a method that completes the decolorization of the crude sugar fatty acid ester and the decomposition of the fatty acid ester is adopted.

The method of decolorizing colored substances using hydrogen peroxide is a well-known method in many industrial fields, but according to the results of various studies conducted by the present inventors, an aqueous solution of a crude sugar fatty acid ester, Alternatively, even if an attempt was made to decolorize an aqueous suspension using only hydrogen peroxide, the decolorizing effect was extremely insufficient, and it was found that this was not suitable for practical use. That is, an aqueous solution or aqueous suspension of a crude sugar fatty acid ester that has been adjusted to an alkaline pH of 8 or higher can be decolored to some extent with hydrogen peroxide alone, but the decolorizing effect is extremely insufficient. In a weakly alkaline to acidic region with a pH of less than 8, it was almost impossible to decolorize with hydrogen peroxide alone.

In the present invention, when decolorizing crude sugar fatty acid esters with hydrogen peroxide, by allowing a lipolytic enzyme to coexist at least at some point, the present invention is extremely effective in a wide pH range that would not be possible with the use of hydrogen peroxide alone. It was completed based on the completely unexpected discovery that it was possible to bleach the color.
Furthermore, impurity fatty acid esters can be decomposed into fatty acids and alcohols that can be easily separated and removed by lipolytic enzymes.

The amount of water added when preparing an aqueous solution or suspension of a crude sugar fatty acid ester is usually such that the concentration of the crude sugar fatty acid ester is 1 to 90% by weight, preferably 5 to 70% by weight. , more preferably 10-50% by weight
It is best to add it so that If the amount of water added is too large, a large amount of energy is required to remove the water afterwards, which is uneconomical, and if the amount of water added is too small, the viscosity of the aqueous solution or suspension increases. Both are unfavorable because the effects of the present invention cannot be fully exhibited.

Although pure hydrogen peroxide with a content of 100% by weight can be used, it is preferable to use an aqueous solution mainly from the viewpoint of safety such as prevention of hazards during handling. The concentration of the aqueous solution is not particularly limited, but is usually about 5 to 60% by weight, preferably about 10 to 40% by weight.

In addition, acylglycerol lipase is a typical example of a lipolytic enzyme, and specifically, acylglycerol lipase derived from Rhizopus, acylglycerol lipase derived from Aspergillus, acylglycerol lipase derived from Mucoa, acylglycerol lipase derived from Pseudomonas, and acylglycerol lipase derived from Cyandida. glycerol lipase,
Examples include pancreatic secretion-derived acylglycerol lipase.

Furthermore, the lipolytic enzyme does not necessarily have to be purified acylglycerol lipase, and any enzyme that has lipolytic activity and does not decompose sugar fatty acid esters can be used.

The amount of hydrogen peroxide and lipolytic enzyme used depends mainly on the hue of the crude sugar fatty acid ester and the content of fatty acid esters. Based on pure hydrogen peroxide in weight%
The amount is preferably about 0.001 to 10% by weight, preferably about 0.005 to 5% by weight, and more preferably about 0.01 to 3% by weight. If the amount of hydrogen peroxide used is less than the lower limit above, the decolorizing effect will not be sufficiently exhibited, and if it is used in an amount larger than the upper limit, there will be no particular effect and it will be uneconomical. Neither is preferable.

Regarding lipolytic enzymes, although it depends on the origin, purity, potency, etc., it is usually 0.0001 to 20% by weight, preferably 0.0005% by weight based on the crude sugar fatty acid ester.
~10% by weight, more preferably about 0.001~5% by weight. If the amount of lipolytic enzyme used is less than the lower limit above, it will be difficult to fully exhibit the effects of the present invention, and if it is used in an amount greater than the upper limit, it will not be economical. Undesirable.

When treating an aqueous solution or suspension of a crude sugar fatty acid ester using hydrogen peroxide and a lipolytic enzyme, the pH is usually 2 to 10, preferably 3 to 10.
It is preferable to adjust it to 9.5, more preferably 4 to 9. As pH regulators, acids such as organic acids and inorganic acids, hydroxides, carbonates, hydrogen carbonates, oxides and ammonia of alkali metals or alkaline earth metals, bases such as organic amines, acid salts, Salts such as basic salts can be used.

In addition, the temperature is usually 10 to 80℃, preferably 20 to 60℃,
More preferably, the temperature is maintained at 25 to 50°C.

If the pH and temperature are outside the above ranges, it will be difficult to fully exhibit the effects of the present invention, and especially under strongly acidic or basic conditions and at high temperatures, the acidity of the sugar fatty acid ester itself will be reduced. This is not preferable because pure chemical hydrolysis reactions using base catalysts tend to occur simultaneously.

The time required to treat an aqueous solution or aqueous suspension of crude sugar fatty acid esters using hydrogen peroxide and a lipolytic enzyme depends in large part on the time required for the lipolytic enzyme to decompose the fatty acid ester. Moreover, the amount of lipolytic enzyme used,
Although it varies depending on the type, potency, characteristics, type of fatty acid ester, content rate, etc., it usually lasts for 1 to 100 hours.
The time is preferably about 2 to 80 hours, and more preferably about 3 to 60 hours.

In addition, when treating with hydrogen peroxide and a lipolytic enzyme, it is preferable to stir the aqueous solution or suspension of the crude sugar fatty acid ester.

By employing the above-mentioned suitable treatment conditions using hydrogen peroxide and lipolytic enzymes, the crude sugar fatty acid esters are decolorized and most or almost all of the impurity fatty acid esters are decomposed into fatty acids and alcohols. can do.

The thus obtained solution treated with hydrogen peroxide and a lipolytic enzyme can be easily purified with good color by appropriately combining known purification methods such as filtration, conversion to other derivatives of fatty acids, solvent extraction, and recrystallization.
Moreover, a highly purified sugar fatty acid ester can be obtained.

As detailed above, according to the present invention, crude sugar fatty acid esters can be decolorized and impurity fatty acid esters can be decomposed into easily separated fatty acids and alcohols, and the loss of sugar fatty acid esters can be substantially reduced. It is extremely useful industrially because it can prevent

The present invention will be explained in more detail below using Examples and Comparative Examples.

Example 1 Potassium carbonate and potassium hydroxide were used as catalysts,
Crude sucrose fatty acid ester produced by alcoholysis of sucrose and coconut oil (24% by weight sucrose monofatty acid ester, 11% by weight sucrose difatty acid ester, fatty acid monoglyceride)
Contains 10% by weight, 8% by weight of fatty acid diglyceride, 2% by weight of fatty acid triglyceride, 23% by weight of fatty acid potassium, 22% by weight of sucrose, glycerin, etc.) 400Kg
After adjusting the pH to 6.5 by adding acetic acid to 60 kg of the mixed solution, 300 g of hydrogen peroxide solution with a concentration of 35% by weight and 40 g of Lipase M AP-10 [manufactured by Amano Pharmaceutical Co., Ltd.] were added,
The treatment was carried out at 37°C for 20 hours with gentle stirring. After completion of the treatment, the hue and content of fatty acid glycerides were measured according to the following methods (applied mutatis mutandis to other Examples and Comparative Examples).

Method for Measuring Hue 1 g of the treated solution was collected based on solid content, then dissolved in 100 ml of 80% by volume aqueous methanol (filtered as there was some insoluble content) to prepare a solution, and the hue was determined by visual inspection. APHA units). still,
For reference, the hue before processing is also measured according to the above method.

Method for Measuring Fatty Acid Glyceride Content After a portion of the treated solution is collected and freeze-dried, the fatty acid glyceride content is determined using gas chromatography and an internal standard method.

As a result of analysis according to the above measurement method, the following results were obtained.

Hue after processing: APHA20, Hue before processing:
APHA200, fatty acid glyceride content after treatment: fatty acid monoglyceride 3% by weight; fatty acid diglyceride and fatty acid triglyceride were not detected.
The content of sugar fatty acid esters after treatment was determined by a method similar to the method for quantifying fatty acid glycerides, and when compared with the analysis results before treatment, it was found that the sugar fatty acid esters were not substantially decomposed.

Comparative Example 1 A crude sugar fatty acid ester was treated in the same manner as in Example 1 except that Lipase M AP-10 was not used at all, using only 300 g of hydrogen peroxide solution with a concentration of 35% by weight. As a result of measuring the hue after treatment, it was APHA180. Note that no substantial change was observed in the contents of fatty acid glycerides and sugar fatty acid esters after treatment compared to those before treatment.

Comparative Example 2 Lipase M
After processing the crude sugar fatty acid ester using only 40g of AP-10, we analyzed the hue and fatty acid glyceride content after the treatment.
APHA200, fatty acid monoglyceride content is 2.9
% by weight, and fatty acid diglyceride and fatty acid triglyceride were not detected.

Comparative Example 3 A mixed solution (PH10) of 40 kg of the same crude sugar fatty acid ester and 60 kg of water as used in Example 1 was added with acetic acid to maintain the same pH without lowering the pH.
300 g of hydrogen peroxide solution with a concentration of 35% by weight was added, and the mixture was treated at 37° C. for 20 hours with stirring. Unlike in Example 1 and Comparative Example 1, intense foaming was observed for 1 to 2 hours after the addition of the hydrogen peroxide solution, but the treatment was continued. As a result of measuring the hue after treatment, it was APHA80.

Example 2 Using only 40g of Lipase M AP-10 in advance
After processing for an hour, hydrogen peroxide solution with a concentration of 35% by weight
The crude sugar fatty acid ester was treated in the same manner as in Example 1, except that 300 g was added and the treatment was continued for an additional 5 hours. As a result of the analysis, the hue after processing is
The content of APHA20-30 and fatty acid monoglyceride was 2.5% by weight, and fatty acid diglyceride and fatty acid triglyceride were not detected.

Example 3 Potassium carbonate and potassium hydroxide were used as catalysts,
Crude sugar fatty acid esters produced by alcoholysis of sucrose and beef tallow (21% by weight of sucrose monofatty acid ester, 11% by weight of sucrose difatty acid ester, 8% by weight of fatty acid monoglyceride, 8% by weight of fatty acid diglyceride) , 3% by weight of fatty acid triglyceride, 49% by weight of fatty acid potassium, sucrose, glycerin, etc.) and 70kg of water, add citric acid to adjust the pH to 5.8, and then create a hydrogen peroxide solution with a concentration of 35% by weight. 500g and Lipase P [Amano Pharmaceutical Co., Ltd.]
Add 60g of the product and heat to 40℃ with gentle stirring.
The treatment was carried out for 15 hours. As a result of the analysis, hue after treatment: APHA10, hue before treatment: APHA250 Content of fatty acid glyceride after treatment: fatty acid monoglyceride 1.5% by weight; fatty acid diglyceride and fatty acid triglyceride were not detected. Incidentally, virtually no decomposition of the sugar fatty acid ester was observed during the treatment.

Example 4 Crude sugar fatty acid ester obtained by alcoholysis of sucrose and propylene glycol monostearate using potassium carbonate as a catalyst (24% by weight of sucrose monostearate, 5% by weight of sucrose distearate, propylene glycol) Contains 20% by weight of monostearate, potassium stearate, sucrose, propylene glycol, etc.) 200g and water
After adjusting 800g of mixed liquid to pH 8 with hydrochloric acid, 35% by weight
5 g of concentrated hydrogen peroxide solution and 0.1 g of lipase P were added, and the mixture was treated at 35° C. for 30 hours with gentle stirring. As a result of analysis, hue after processing:
APHA20, hue before treatment: APHA300, content of propylene glycol monostearate after treatment: 2% by weight.

Example 5 25% by weight of sucrose monostearate, 15% by weight of sucrose distearate, 5% by weight of methyl stearate, 30% by weight of sodium stearate and sucrose
Crude sugar fatty acid ester containing 25% by weight 350
After adjusting the pH of a mixture of g and 650 g of water to 7 with oxalic acid,
Add 0.07 g of Lipase AP-4 [manufactured by Amano Pharmaceutical Co., Ltd.],
After treating at 32℃ for 20 hours with gentle stirring, 10g of hydrogen peroxide solution with a concentration of 10% by weight was added to 32℃.
Treatment was continued for a further 5 hours at a temperature of .degree. As a result of analysis, hue after processing: APHA40, hue before processing:
The content of methyl stearate in APHA400 after treatment was 0.1% by weight.

Example 6 Contains 35% by weight of sucrose tallow fatty acid ester (monoester/diester = 60/40 weight ratio), 21% by weight of beef tallow fatty acid ester of diethylene glycol monoethyl ether, 25% by weight of potassium tallow fatty acid, and 19% by weight of sucrose Crude sugar fatty acid ester
After adjusting the mixture of 100g and 400g of water to PH6.5 with acetic acid,
1.5 g of 35% hydrogen peroxide and lipase
Add 0.1g of P and heat at 35℃ for 24 hours while stirring gently.
Time processed. As a result of analysis, hue after processing:
APHA30, hue before treatment: APHA300, content of tallow fatty acid ester in diethylene glycate monoethyl ether after treatment: 1.5% by weight.

Example 7 Roughinose coconut fatty acid ester (monoester/diester/triester = 60/30/10
50 g of crude sugar fatty acid ester containing 40% by weight (weight ratio), 25% by weight of coconut fatty acid glyceride (monoglyceride/diglyceride/triglyceride = 50/40/10 weight ratio), 20% by weight of coconut fatty acid potassium, and 15% by weight of raffinose; 50g water
After adjusting the mixed solution to PH6.0 with citric acid, 35% by weight
Concentrated hydrogen peroxide solution 0.5g and Lipase M AP-
100.1 g was added and the treatment was carried out at 30° C. for 48 hours with stirring. As a result of analysis, hue after processing: APHA10,
Hue before treatment: APHA240, coconut fatty acid monoglyceride content after treatment: 1.4% by weight,
Coconut fatty acid diglyceride and coconut fatty acid triglyceride were not detected.

It should be noted that substantially no decomposition of the sugar fatty acid ester (roughinose coconut fatty acid ester) was observed during the treatment.

Claims (1)

[Claims] 1. An aqueous solution or aqueous suspension of a crude sugar fatty acid ester containing at least fatty acid esters as impurities is treated with hydrogen peroxide and a lipolytic enzyme to decolorize the crude sugar fatty acid ester. A method for decolorizing and purifying sugar fatty acid esters, which comprises decomposing fatty acid esters. 2. A method for decolorizing and purifying sugar fatty acid esters according to claim 1, wherein decolorization with hydrogen peroxide and decomposition of fatty acid esters with a lipolytic enzyme are carried out simultaneously. 3. The method for decolorizing and purifying sugar fatty acid esters according to claim 1, wherein fatty acid esters are decomposed in advance by a lipolytic enzyme and then decolorized by hydrogen peroxide. 4. The method for decolorizing and purifying sugar fatty acid esters according to claim 1, wherein the crude sugar fatty acid esters are reaction products obtained by alcoholysis of sugars and fatty acid esters in the presence of a base catalyst. . 5 Claims 1, 2, and 3 in which the fatty acid ester is a glycerin fatty acid ester
or the method for decolorizing and purifying sugar fatty acid esters according to item 4. 6 Claim 1 in which the fatty acid ester is a fatty acid ester of an aliphatic lower monohydric alcohol
The method for decolorizing and purifying sugar fatty acid esters according to item 1, 2, 3, or 4. 7 Claim 1 in which the fatty acid ester is a fatty acid ester of an aliphatic lower dihydric alcohol
The method for decolorizing and purifying sugar fatty acid esters according to item 1, 2, 3, or 4. 8 Claims 1, 2, and 3 in which the fatty acid ester is carbitol fatty acid ester
or the method for decolorizing and purifying sugar fatty acid esters according to item 4. 9. The method for decolorizing and purifying sugar fatty acid esters according to claim 1, 2, or 3, wherein the lipolytic enzyme is acylglycerol lipase.