JPH0412114B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for hydrolyzing fats and oils containing long-chain unsaturated fatty acids with a high decomposition rate and easy post-treatment using lipase.

Methods for hydrolyzing fats and oils include saponification, high-pressure decomposition, and Teutschiel decomposition, and the fatty acids obtained by these methods are markedly colored;
Distillation is essential as a post-processing step.

However, long-chain unsaturated fatty acids with carbon atoms of 20 or more have a high boiling point, so not only do they require energy and cost under high vacuum and high temperatures, but exposure to high temperatures increases the amount of distillation residue due to polymerization, reducing the distillation yield. When the percentage decreases and a large amount of polyenoic acid of tetraene or higher is contained, such as fish or whale oil,
Even if they are distilled, they have the disadvantage that double bond isomerization occurs, resulting in the production of large amounts of polyenoic acid isomers.

Therefore, a lipase enzymatic decomposition method is known that does not require distillation, which is essential for chemical hydrolysis. Conventional results of hydrolysis have shown that the decomposition rate actually progresses to only about 60%. In other words, fatty acids with carbon numbers of 18 or less are very easily hydrolyzed;
It is known that the above fatty acids are difficult to be hydrolyzed. Utilizing this, as described in JP-A-58-165796, it becomes possible to hydrolyze fatty acids with 18 or fewer carbon atoms and separate fatty acids with 20 or more carbon atoms as glycerides.

Therefore, in order to increase the decomposition rate of oils and fats containing long-chain unsaturated fatty acids, the present inventors have intensively investigated reaction methods such as the amount of enzyme, the pH of water, the amount of water, and the presence or absence of additives. Since lipolytic enzymes with regioselectivity do not hydrolyze fatty acids at the 2-position, the maximum hydrolysis rate is approximately 60%, and lipolytic enzymes without triglyceride regioselectivity do not hydrolyze the amount of water or amount of enzyme added. Change the decomposition conditions to industrially impractical conditions (e.g. oil:water = 1:50-100,
Even when reacting for a long time with 20,000 units of enzyme per gram of oil, the maximum decomposition rate remained at 70%.

Therefore, as a result of further delving into the composition of decomposed products by fat-degrading enzymes depending on the presence or absence of triglyceride regioselectivity, we found that by combining specific enzymes, fats and oils containing long-chain unsaturated fatty acids with carbon atoms of 20 or more can be hydrated. The inventors have discovered that it is possible to increase the decomposition rate and obtain fatty acids with high yield and high neutralization value, leading to the present invention.

That is, the present invention provides a method for hydrolyzing fats and oils containing long-chain unsaturated fatty acids having 20 or more carbon atoms using a lipase that has triglyceride regioselectivity and a lipase that does not have triglyceride regioselectivity. The present invention relates to a method for hydrolyzing fats and oils, characterized in that the ratio of fat and oil hydrolyzing activity units of the lipase having the above and the lipase having no triglyceride regioselectivity is 1:1 to 30.

In carrying out the present invention, fats and oils containing long-chain unsaturated fatty acids are hydrolyzed by adding a lipase with and without triglyceride regioselectivity simultaneously or during the reaction, and then By separating the lipase and aqueous phases, high degradation products are obtained.

In the present invention, the long chain unsaturated fatty acid has 20 carbon atoms.
The above monoenoic acids, dienoic acids, trienoic acids, tetraenoic acids, pentaenoic acids, hexaenoic acids, etc.
Natural oils and fats that contain large amounts of these include fish oil, whale oil, high erucic acid rapeseed oil, mustard oil, etc., but the raw materials that can be used in the present invention are mixed oils, conjugated isomerized oils, or water containing any of these. Added oil may also be used.

In the present invention, the lipases having triglyceride regioselectivity used include lipases obtained from the genus Aspergillus and Rhizopus of microbial origin, and pancreatin of animal origin. Lipases obtained from Aspergillus niger, Rhizopus delemar and Pancreatin are preferred.

In addition, lipases without triglyceride regioselectivity include those of the genus Penicillium and Geotricum, which originate from microorganisms.
In particular, lipases obtained from Geotrichum candidum and Candida cylindracea are preferably used.

The hydrolysis conditions may be carried out according to known methods, but the amount of lipase used is such that the ratio of lipase with regioselectivity to lipase without regioselectivity is 1:1 to 30 in terms of fat and oil hydrolyzing activity units; Furthermore, when expressed as U (unit), which indicates fat and oil hydrolysis activity, lipase with regioselectivity has 60 to 1000 U, and lipase without regioselectivity has 200 to 3000 U, per 1 g of reaction substrate (oil). It is preferable to do so. More preferably, the former and latter lipases are
The ratio of fat and oil hydrolyzing activity units is 1:3 to 15, with the former lipase being 100 to 500 U, and the latter lipase being 1:3 to 15.
It should be 300 to 1500U.

The amount of water added is preferably 30 to 500% (by weight, same hereinafter), more preferably 50 to 200%, based on the fat or oil. In a small amount of water, hydrolysis does not proceed easily due to an equilibrium reaction. Moreover, if it exceeds 500%, economical decomposition is not possible.

The pH of water is preferably in the range of 4.5 to 8.5, and it is more effective to use a buffer to adjust the pH, with a particularly desirable pH range of 5.5 to 8.0. Furthermore, for a more effective reaction,
Emulsifiers such as polyvinyl alcohol and fatty acid esters can also be used, and addition of bile salts is also effective in increasing hydrolysis activity. The hydrolysis reaction may be carried out in the atmosphere, but if it contains a large amount of long-chain highly unsaturated acids, such as fish oil or whale oil, it may be carried out under an inert gas atmosphere, such as nitrogen gas or carbon dioxide atmosphere. Leaving it for a long time not only prevents deterioration of fatty acids, but also prevents enzyme deactivation. Also, antioxidants, such as tocopherols,
TBHQ, BHA, and BHT may be used together.

The hydrolysis reaction is preferably carried out at 20-60°C. Below 20°C, the reaction is slow, and above 60°C, the enzyme is inactivated. It is more preferable to carry out the reaction at a temperature of 30 to 50°C.

Although it is preferable to stir the reaction, the reaction can also be carried out in an emulsified state and allowed to stand still. Further, the reaction may be a single-stage reaction, but may also be a multi-stage reaction in order to proceed more efficiently and quickly. An immobilized enzyme column can also be used for continuous reaction.

When fats and oils containing long-chain unsaturated fatty acids with carbon atoms of 20 or more are hydrolyzed as described above, lipase having triglyceride regioselectivity and lipase not having triglyceride regioselectivity are used in large numbers, respectively. Hydrolyzed fats and oils with a higher decomposition rate than when hydrolyzed alone can be obtained. That is, the decomposition rate by this method is approximately 20% higher than that by the single method.

Examples are shown below.

Example 1 To 20 g of fish oil (=172.5), 18,000 units of lipase (360,000 units/g) obtained from Candida cylindrasiae was added, and 10,000 units of lipase obtained from Rhizopus deremer (3,500 units/g) were added. , 25ml distilled water
added. The reaction was carried out at 40°C for 5 hours while stirring. Thereafter, the aqueous layer was separated to obtain cracked oil. The neutralization value of this cracked oil was 149.3, and the saponification value was 190.1 (decomposition rate 78.5%).

Example 2 The reaction was carried out in the same manner as in Example 1 for 24 hours. The neutralization value of the resulting cracked oil is 169.2, and the saponification value is 191.5.
(decomposition rate 88.4%).

Example 3 To 20 g of fish oil (=169.2), 18,000 units of lipase obtained from Candeida Cylindrassie (360,000 units/g) were added, and further 1,500 units of pig pancreatic lipase (2,500 U/g) were added.
Add 20 ml of 0.1M phosphate buffer with pH 7.0, under nitrogen,
The reaction was carried out at 35°C for 24 hours. The neutralization value of cracked oil is 189.5,
The saponification value was 191.9 (decomposition rate 98.7%).

Example 4 The cracked oil that had been reacted for 5 hours in the same manner as in Example 1 was further subjected to a second stage reaction for 5 hours. The resulting cracked oil had a neutralization value of 188.5 and a saponification value of 192.0 (decomposition rate 98.2%).

Example 5 To 20 g of high erucic acid rapeseed oil (=104.2, erucic acid content 42.8%), 1500 units of lipase originating from Diotrichum candidum (9000 U/g) was added, and further 1000 units of lipase originating from Rhizopus deremer (3500 units/g) was added. Then, 40 ml of distilled water was added, and the mixture was reacted for 5 hours with stirring at 40°C in the atmosphere. The resulting cracked oil had a neutralization value of 169.7 and a saponification value of 179.0 (decomposition rate 94.6%).

Comparative Example 1 36,000 units of lipase obtained from Candeida Cylindrassie (360,000 units/g) was added to 20 g of fish oil (=169.2), and 25 ml of distilled water was added.
The reaction was carried out for 24 hours at 40°C under nitrogen. The neutralization value of cracked oil is
123.8, saponification value was 190.0 (decomposition rate 65.2
%).

Comparative Example 2 To 20 g of high erucic acid rapeseed oil (=104.2, erucic acid content 42.8%), 36,000 units of lipase originating from Rhizopus deremer (37,000 units/g) was added, 40 ml of distilled water was added, and the mixture was stirred at 40°C in the atmosphere. The reaction took place for 5 hours. The neutralization value of the obtained cracked oil is
120.6, and the saponification value was 178.1 (decomposition rate 67.7).
%).

Comparative Example 3 20 g of fish oil (=169.2), 12,000 units of lipase obtained from Candida cylindrasiae (360,000 units/g), and lipase (3,500 units/g) obtained from Rhizopus deremer.
24,000 units were added, 25 ml of distilled water was added, and the mixture was reacted at 40°C for 24 hours with stirring. After this, the aqueous layer was separated to obtain cracked oil. The neutralization value of this decomposed oil is
116.8, and the saponification value was 190.1 (decomposition rate 61.4).
%).

Comparative Example 4 20 g of fish oil (=169.2) was mixed with 35,000 units of lipase obtained from Candida cylindrasiae (360,000 units/g) and 35,000 units of lipase obtained from Rhizopus deremer (3,500 units/g).
700 units were added, 25 ml of distilled water was added, and the mixture was reacted at 40°C for 24 hours with stirring. After this, the aqueous layer was separated to obtain a separated oil. The neutralization value of this decomposed oil is
121.5, saponification value was 190.5 (decomposition rate 63.8
%).

Claims (1)

[Scope of Claims] 1. When hydrolyzing fats and oils containing long-chain unsaturated fatty acids having 20 or more carbon atoms using a lipase that has triglyceride regioselectivity and a lipase that does not have triglyceride regioselectivity, the triglyceride position A method for hydrolyzing fats and oils, characterized in that the lipase having selectivity and the lipase not having triglyceride regioselectivity are used in a ratio of fat and oil hydrolyzing activity units of 1:1 to 30. 2. The hydrolysis method according to claim 1, wherein the long-chain unsaturated fatty acid-containing fat or oil having 20 or more carbon atoms is fish oil, whale oil, rapeseed oil, or mustard oil. 3. The hydrolysis method according to claim 1 or 2, wherein the amount of water relative to the fat or oil is 30 to 500% by weight. 4. The hydrolysis method according to any one of claims 1 to 3, wherein the hydrolysis reaction temperature is 20 to 60°C.