JP2735505B2 - Docosahexaenoic acid-containing fats and oils - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to docosahexaenoic acid-containing fats and oils used for various foods.

[0002]

2. Description of the Related Art Docosahexaenoic acid (hereinafter abbreviated as DHA) is known to be contained in a large amount in marine animal fats and oils, particularly fish oil, and to have various physiological functions. Research on advanced purification technology and enrichment technology for this purpose is underway.

[0003]

The DHA-containing fats and oils have a good flavor immediately after purification, but in particular, fish oils, which are typical examples of marine animal fats and oils containing a large amount of DHA, are slightly oxidized during storage, and thus the fish oils have a slight oxidation. There is a problem that a peculiar odor, a so-called lintel odor, is generated, and the commercial value of the edible oil or fat is reduced.

In order to alleviate this problem as much as possible, first, it is conceivable to reduce the amount of fish oil to be added when used in foods. Then, in order to obtain fats and oils with a high DHA content, concentration of DHA has been attempted.

[0005] Here, looking at the properties of the concentrated fish oil,
Fish oil has a relatively high distribution of polyunsaturated fatty acids such as DHA at the second position, so-called β-position, of triglyceride molecules, and it is known that triglyceride molecules having two polyunsaturated fatty acids in one molecule are also present. I have.

[0006] In the fats and oils concentrated so as to contain DHA at a high concentration, the content of triglyceride molecules having two or more polyunsaturated fatty acids in one molecule is naturally increased. Compared to fats and oils before DHA is concentrated, they have the disadvantages that they are very easily oxidized and the flavor deteriorates quickly.

As described above, the amount of DHA-containing fats and oils added to food can be reduced by the operation of concentrating the fats and oils, but this increases the number of molecules that are more susceptible to attack by the chain reaction in oxidation. It did not come to a satisfactory resolution.

Further, among various triglycerides in which eicosapentaenoic acid (hereinafter abbreviated as EPA), which is a kind of polyunsaturated fatty acid, and palmitic acid, which is a saturated fatty acid, are ester-bonded, the total EPA content in the triglyceride is the same. In addition, fats and oils containing triglyceride molecules having three EPAs in one molecule are one EPA in one molecule.
There is also a report that the oxidation stability is clearly inferior to that of fats and oils containing triglycerides having

[0009] From these facts, when the fat or oil enriched in DHA is mixed with another fat or oil containing no polyunsaturated fatty acid to prepare the same DHA content as before the concentration, this fat and oil is It can also be inferred that the oxidation stability is inferior to that of the fat before concentration.

In practice, when adding DHA-containing fats and oils to foods, the concentration of the fats and oils to be added is doubled, and the amount added to the foods is reduced to half the specified amount. The flavor was not so much improved as compared to the case where no fats and oils were added in a specified amount.

[0011] Therefore, it is difficult to add an arbitrary amount of a DHA-containing fat or oil to a food in a savory state by means of concentrating DHA to reduce the amount of the DHA-containing fat or oil added to the food.

[0012] Therefore, it is considered that it is better not to concentrate highly unsaturated fatty acids in one molecule as much as possible.
In this regard, there is a report that the oxidative stability is improved by randomly transesterifying only fish oil. However, there is no noticeable effect in improving the flavor of fish oil, and it is not satisfactory for use as food. In fact, immediately after addition to food and after storage for a predetermined period of time, D is satisfactory with respect to flavor and oxidation stability.
HA-containing fats and oils have not yet been obtained.

[0013] Accordingly, an object of the present invention is to solve the above-mentioned problems and to improve the flavor of DHA-containing fats and oils without limiting the amount added to foods. An object of the present invention is to provide a DHA-containing fat or oil which can suppress generation of odor and has high oxidation stability.

[0014]

In order to solve the above-mentioned problems, the present invention provides a docosahexaenoic acid content of 10%.
100% by weight or more of fat and oil, rice oil, cottonseed oil, sesame
At least one plant selected from the group consisting of oil and corn oil
Fats or oils, or their hardened oils or their fractionated oils 25-4
And a transesterification reaction using a lipase to mix rice oil, cottonseed oil, sesame oil or
Adopts a means for preparing a docosahexaenoic acid-containing oil or fat containing an antioxidant component of corn oil and having a docosahexaenoic acid content of 2 to 30% by weight in all constituent fatty acids.

The details will be described below. The fats and oils used in the present invention are those used as ordinary edible fats and oils, and may be any fats and oils containing 10% by weight or more of DHA, and there is no particular limitation. Specific examples of such fats and oils Examples thereof include tuna oil, bonito oil, sardine oil, horse mackerel oil, mackerel oil, squid oil, and one or more oils or fats selected from these groups, or such oils or fats as a raw material if necessary. Oils and fats concentrated so that DHA becomes 10% by weight or more may be used.

If the DHA content is less than 10%, the amount of vegetable oil mixed for transesterification becomes extremely small,
In this case, the DH which is stabilized and flavorful enough for the purpose
This is because A-containing fats and oils cannot be obtained.

In the present invention, there is no upper limit to the DHA content of the fat or oil used for transesterification, but it is preferably 40% by weight or less. Even with fats and oils having a DHA content exceeding 40% by weight, the fats and oils obtained by transesterification
By adjusting the blending amount of vegetable oils and fats so that the HA content is 2 to 30% by weight, and transesterifying, it is possible to obtain oils and fats containing DHA which is stabilized and has a good taste. However, if the DHA content is more than 40% by weight, the cost of concentration increases, and the flavor does not significantly increase in proportion to the cost. In practice, it is preferable to use the DHA content of 40% by weight or less. .

The fats and oils obtained by concentrating the DHA to a predetermined concentration include concentrated fats and oils by a fractionation method without using a solvent, concentrated fats and oils by a fractionation method using a solvent, concentrated fats and oils using enzymes or microorganisms, and supercritical gas. Fats and oils concentrated by an extraction method utilizing sucrose can be employed.

The method for concentrating fats and oils by the above-mentioned fractionation method without using a solvent is usually a method called wintering or a method called spontaneous fractionation, in which the fats and oils are partially crystallized at a low temperature. This is a method of fractionating the deposited crystal part and the liquid part.

The temperature in this case depends on the melting point of the DHA-containing fat or oil as a raw material, but is usually in the range of 0 to 20 ° C.
The fats and oils must not be completely solidified. In this case, the increase in DHA content is not very large, between 2 and 5% by weight.

In the case of the method of concentrating fats and oils by a fractionation method using a solvent, hexane and acetone can be used as a solvent, and fish oil as a raw material is dissolved in 2 to 10 times the volume of a solvent, and the solution is cooled. The precipitated crystal part and the fat part dissolved in the solvent are separated. In this case, -20 to -70 ° C
By performing the fractionation at a very low temperature, it is possible to concentrate such that DHA is increased by 5% by weight or more. Both are D
HA is concentrated in the amorphous or liquid portion.

In the method for enriching DHA using an enzyme, an enzyme and conditions may be selected such that fatty acids other than DHA are hydrolyzed by lipase and DHA is left in the form of glycerin ester. For fish oils such as bonito oil and tuna oil, DH
Since A is concentrated at the 2-position of the triglyceride, the so-called β-position, by using an enzyme which is difficult to cut this position, the 1,3-position is specifically hydrolyzed to relatively DHA.
The content can be increased. Such enzymes include:
Lipases derived from the genera Aspergillus, Mucor, and Alcaligenes are included.

It is also possible to increase the DHA content by using an enzyme which is relatively difficult to break the ester bond between DHA and glycerin. Such enzymes include:
A lipase derived from Candida sirindrache can be exemplified.

Microorganisms that produce lipase can be used instead of lipase. As the concentration method, a method for producing a fat and oil containing a high content of docosahexaenoic acid (Japanese Patent Application No. 81654/1994) can be adopted. Gas extraction using a supercritical gas mainly uses carbon dioxide gas.

In the present invention, the vegetable oil to be mixed with the DHA-containing oil for transesterification is an edible vegetable oil having an iodine value of 70 to 130.
And at least one vegetable oil selected from the group consisting of rice oil, cottonseed oil, sesame oil and corn oil, or a hardened oil thereof. Alternatively, the most favorable results have been obtained using the fractionated oil.

The vegetable oils and fats used in the present invention preferably contain as little as possible unsaturated fatty acids having 3 or more double bonds, preferably oils and fats rich in monoenoic acid. Because, when a large number of unsaturated fatty acids having 3 or more double bonds are contained, even if transesterification is performed,
This is because the concentration of fatty acids having a large number of double bonds in one triglyceride molecule increases, and many triglyceride molecules having poor stability can be formed. Thus, in order to maintain good flavor, it is necessary to vary the distribution of DHA in triglycerides and to limit the DHA content to a specific range.

Second, vegetable oils and fats which are liquid at room temperature are desirable. The reason is that, even if it is quite stable, if a lot of fats and oils having an extremely high melting point, for example, those having a melting point of 50 ° C. or more, are mixed, the melting point of the final DHA-containing fats and oils becomes high, This is because it is necessary to melt the heat-treated material at a high temperature, which makes it susceptible to oxidation.

Vegetable oils and fats satisfying the above conditions are:
Other than rice oil, cottonseed oil, sesame oil, and corn oil, DH
Flavor during storage after transesterification with A-containing fats and oils,
Nothing was superior to these fats in oxidative stability.

This is because fats and oils each have a unique flavor, even if refined, and each contains a different trace component. Many of these trace components have an antioxidant function, which causes the oil or fat to have a stability that cannot be explained only by the fatty acid composition of the oil or fat. And rice oil, cottonseed oil,
DHA, a trace amount of antioxidant component contained in sesame oil and corn oil
This is considered to be because the oxidation inhibitory effect of is well exhibited after transesterification.

This is evident from the fact that the oxidation of the equivalent mixed fats and oils without transesterification is not suppressed (Comparative Examples 4 to 7). In the present invention, it is considered that the stability is improved by the change in the positional composition of glyceride due to transesterification and the interaction of the antioxidant component contained in the fat or oil in advance.

For example, rice oil is known to contain γ-tocopherol and ferulic acid, and it is thought that there are still many unknown antioxidant components including analogs thereof. . Then, a trace amount of each flavor component also acts to make the flavor of the fish oil hardly felt after transesterification. As for rice oil, cottonseed oil, sesame oil, and corn oil, one or more of the respective hardened oils and fractionated oils can be used.

In the method of transesterification, a method using an enzyme lipase is employed. This is because the conventional method using sodium methylate or caustic soda-glycerin-water, which is a chemical catalyst, has an effect of improving the oxidation stability and flavor of the DHA-containing oil and fat after the reaction, as compared with the method using lipase. Is low. In addition, the type of enzyme to be used has no specificity with respect to the position of triglyceride, and performs a so-called randomization reaction.
Either one having specificity to the position 3 or any one can be used, but in order to distribute DHA more uniformly, an enzyme which performs a randomization reaction is preferable. The origin of the enzyme is not particularly limited, but a lipase derived from the genus Candida is preferable if the enzyme performs a randomization reaction, and a lipase derived from the genus Alcaligenes is preferable if the enzyme is a 1,3-specific reaction. For practical use, lipase immobilized on diatomaceous earth may be used to facilitate the reaction and the subsequent recovery of oils and fats. The reaction may be carried out in accordance with the production of transesterified oil using ordinary lipase, and may be either a batch reaction or a continuous reaction using a column-shaped reactor.

For use in foods, the transesterified DHA-containing fats and oils are subjected to a known treatment, if necessary, as a step for refining edible fats and oils. Needless to say, it is necessary to perform a process for removing odorous components, that is, a process called deodorization.

[0034]

The DHA-containing fats and oils of the present invention prepared through the above-mentioned treatment steps have a uniform distribution of DHA in the glycerides in the fats and oils without being biased to some glyceride molecules. Or, because it contains an effective antioxidant component in cottonseed oil, sesame oil, or corn oil, it has a very good taste compared to conventional DHA-containing fats and oils from the beginning of production, and the generation of a characteristic odor during subsequent storage It is an oil and fat that is suppressed and has excellent oxidation stability.

[0035]

【Example】

[Example 1] DHA content was 25% by weight in all constituent fatty acids.
750 g of bonito oil and 250 g of rice oil containing iodine value and linolenic acid shown in Table 1 were mixed and immobilized with a lipase derived from Candida cylindrache (manufactured by Meito Sangyo Co., Ltd .: Lipase OFG), and a random transesterification reaction was performed at 60 ° C. for 7 hours. After the reaction, the oil from which the enzyme was separated and removed was subjected to alkali deacidification and activated clay treatment, and finally to deodorization treatment at 215 ° C. for 1 hour by steam distillation under reduced pressure.

After adding 500 ppm of tocopherol (manufactured by HONEN CORPORATION) to 850 g of the fat and oil after the deodorizing treatment, the DHA content in the fatty acid composition was measured by gas chromatography, and the results are also shown in Table 1.

Further, among the obtained DHA-containing fats and oils, 1
00g was placed in a 200 ml beaker, the upper part was covered with a petri dish and stored at 60 ° C., and the change with time of the peroxide value of the fat (0 to 90 hours) was examined. 0-90 hours) was examined by sensory tests.

The above sensory test was conducted for 3
With a person as a panelist, they do not feel any fishy odor (marked with ◎), hardly feel the fishy smell (marked with ○), and feel a little fishy odor (△)
Mark), feel the odor (x mark)
These results are shown together in Table 1 or shown in Table 2.

[0039]

[Table 1]

[0040]

[Table 2]

[Examples 2 to 4] In Example 1, DHA-containing fats and oils using cottonseed oil instead of rice oil (Example 2), DHA-containing fats and oils using sesame oil (Example 3), and corn oil were used. Prepared DHA-containing fats and oils (Example 4),
Deodorization by steam distillation was performed in exactly the same manner as in Example 1, and then the same amount of tocopherol was added for analysis (fatty acid composition) and storage test (peroxide value and odor sensory test). These results are shown in Table 1 or Table 2.

[Comparative Examples 1 to 7] Example 1 wherein rapeseed oil was used instead of rice oil in Example 1 (Comparative Example 1).
In Example 1, palm oil was used instead of rice oil (Comparative Example 2), in Example 1, palm oil was used instead of rice oil (Comparative Example 3), and in Example 1, transesterification was not performed ( (Comparative Example 4), those without transesterification in Example 2 (Comparative Example 5), those without transesterification in Example 3 (Comparative Example 6), and those without transesterification in Example 4 (Comparative Example) 7) was prepared and similarly deodorized by steam distillation. Thereafter, the same amount of tocopherol was added to carry out analysis and storage tests. The results are shown in Table 1 or Table 2.

As is clear from the results shown in Tables 1 and 2, Example 1 using rice oil as the oil to be transesterified, Example 2 using cottonseed oil, Example 3 using sesame oil, and corn oil were used. In Example 4 used, the peroxide value (PO
V) was kept very low, and there was no deterioration in flavor.

However, in Comparative Example 1 using rapeseed oil containing a large amount of α-linolenic acid, the POV increased quickly, and an oxidized odor was generated after storage for 20 hours. In addition, iodine value is low,
Comparative Example 2 using coconut oil not containing α-linolenic acid,
Similarly, Comparative Example 3 using palm oil having a low iodine value was not good in the same point. Further, Comparative Example 4 in which only rice oil was mixed without transesterification, Comparative Example 5 in which cotton seed oil was only mixed, Comparative Example 6 in which sesame oil was only mixed,
Comparative Example 7 in which only corn oil was mixed was POV
Rapidly increased, and a raw odor was generated 20 hours after storage.

Example 5 1200 g of bonito oil having a DHA content of 25% by weight in the total constituent fatty acids was partially subjected to an acid value of up to 40 using a lipase derived from Candida syrindrache (trade name: Lipase OF, manufactured by Meito Sangyo Sangyo Co., Ltd.). Hydrolyzed to
Alkali deacidification and activated clay treatment were performed to obtain 600 g of DHA-enriched fish oil (DHA 32.0%). 600 g of this DHA-enriched fish oil and 400 g of rice oil were mixed, and 50 g of a product obtained by immobilizing lipase derived from Candida cylindrache on granular diatomaceous earth (manufactured by Meito Sangyo Co., Ltd .: Lipase OFG) was added. A random transesterification reaction was performed at 60 ° C. for 7 hours. After the reaction, the oil from which the enzyme was separated and removed was subjected to alkali deacidification and activated clay treatment, and finally to deodorization treatment at 215 ° C. for 1 hour by reduced pressure steam distillation.

After adding 500 ppm of tocopherol (manufactured by Honen Corporation) to the fat and oil after the deodorization treatment,
The DHA content in the fatty acid composition was measured by gas chromatography, and the results are shown in Table 1. This 100g
In a 200 ml beaker, cover the top with a petri dish, store at 60 ° C., examine the temporal change of the peroxide value of the oil and fat (0 to 90 hours), The change (0 to 90 hours) was examined by a sensory test, and these results are shown in Table 3 or Table 4, respectively.

[0047]

[Table 3]

[0048]

[Table 4]

[Comparative Example 8] In Example 5, a product which was not subjected to transesterification was prepared, similarly deodorized by steam distillation, and then the same amount of tocopherol was added to conduct an analysis and storage test. Are also shown in Table 3 or Table 4.

As is clear from the results in Tables 3 and 4, Comparative Example 8 in which DHA-enriched fats and oils were simply mixed with rice oil was used.
In the case of PO, the rise in POV was rapid, and an odor was apparently generated due to oxidation of fish oil. On the other hand, in the case where the DHA-enriched fish oil was transesterified with an enzyme, the increase in POV was suppressed, and the odor peculiar to oxidation of the fish oil was not felt.

Example 6 A hardened oil (iodine value: 80, melting point: 30 ° C.) was prepared in place of rice oil in Example 1 (Example 6), and deodorization was similarly performed by steam distillation. After that, the same amount of tocopherol was added for analysis. 100 g of the obtained DHA-containing fat and oil was 200
Take in a ml beaker, store at -20 ° C for one day,
In a constant temperature bath. At this time, the time until complete melting and the peroxide value after melting were measured. The results are shown in Table 5.

[0052]

[Table 5]

[Comparative Example 9] A hardened soybean oil (iodine value: 33, melting point: 55 ° C) (Comparative Example 9) was prepared in place of the hardened rice oil in Example 6, and deodorized by steam distillation in the same manner. Then, the same amount of tocopherol was added for analysis. Thereafter, the same storage was performed, and the melting time and the peroxide value were measured. The results are shown in Table 5.

As is evident from the results in Table 5, Comparative Example 9 using oils and fats having a high melting point took about four times as long as Example 6 to completely dissolve the oils and fats. The oils and fats have also deteriorated. For this reason, when vegetable oils and fats having a high melting point are used in the transesterification, when the DHA-containing oils and fats are melted and used, they are already slightly oxidized.

[Examples 7 to 9] In Example 1, tuna oil (DHA 25%) was used instead of bonito oil (Example 7), and sardine oil (DHA 10%) 200 g and rice oil 800 g were used. (Embodiment 8), Candida
Lipase derived from Sylindrache (made by Meito Sangyo: trade name)
A lipase OF) containing 1000 g of fish oil (DHA 40%) enriched with DHA in bonito oil and 250 g of rice oil (Example 9) was prepared, similarly deodorized by steam distillation, and then the same amount of tocopherol was prepared. Was added, and the same analysis and storage test as in Example 1 was performed. The results are shown in Tables 6 and 7.

[0056]

[Table 6]

[0057]

[Table 7]

From the results of Tables 6 and 7, it can be seen that in Example 7 using tuna oil as the DHA-containing oil and fat, the rise in peroxide value was suppressed to a very low level as in the case of using skipjack oil. The deterioration of the flavor was also very small.

In Example 8 in which the DHA content was 2.0%, the composition was more stable against oxidation. In Example 9 in which the DHA content was 30%, the stability was slightly higher because of the higher DHA content. The DHA-containing fats and oils were sufficiently satisfactory in flavor.

[Example 10] Instead of the lipase derived from Candida silindrache used in Example 1, an immobilized lipase derived from the genus Alcaligenes (trade name: Lipase PLG, manufactured by Meito Sangyo Co., Ltd.) was used to obtain 1,1 of triglyceride. Transesterification was performed randomly at the 3rd position, after the reaction, the same purification treatment was performed, and finally, deodorization by steam distillation was performed. Thereafter, the same amount of tocopherol was added, and analysis and storage tests were performed in the same manner as in Example 1. Tables 8 and 9 show the results.

[0061]

[Table 8]

[0062]

[Table 9]

Comparative Example 10 In place of the immobilized lipase derived from the genus Alcaligenes used in Example 10, 3 g of sodium methylate was used, and a random transesterification reaction was carried out at 70 ° C. for 30 minutes. After the treatment, deodorization was finally performed by steam distillation. After that, the same amount of tocopherol was added, and analysis and storage tests were performed in the same manner as in Example 1. The results are shown in Tables 8 and 9.

From the results in Tables 8 and 9, it can be seen that the DHA-containing fat and oil of Example 10 using the lipase derived from the genus Alcaligenes has a small increase in peroxide value, and also has a raw fishy odor peculiar to fish oil. I couldn't feel it. In contrast, Comparative Example 10 using sodium methylate as a chemical catalyst
In the early stage of storage, the peroxide value was low and the deterioration of the flavor was small, but after 90 hours, the peroxide value was high and the fishy odor was felt.

[0065]

According to the present invention, as described above, the predetermined DH
By mixing a specific vegetable oil with the A-containing fat and oil and transesterifying with a lipase, a stable fat and oil containing 2 to 30% by weight of DHA was obtained. There is an advantage that it can be used without impairing the flavor and without limiting the amount added to the food, and can suppress the generation of a peculiar odor during storage, and can provide a DHA-containing fat or oil having high oxidation stability.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Kazuko Hirata 17 Uozakihama-cho, Higashinada-ku, Kobe Ueda Oil Co., Ltd. JP-A-7-135972 (JP, A)

Claims (3)

(57) [Claims] 1. A method according to claim 1, wherein 100 parts by weight of a fat or oil having a docosahexaenoic acid content of 10% by weight or more is mixed with rice oil, cottonseed oil, sesame oil and coconut oil.
One or more vegetable oils or fats selected from the group consisting of
Or a mixed oil obtained by mixing 25 to 400 parts by weight of the hardened oil or the fractionated oil thereof with a transesterification reaction using a lipase to produce rice oil, cottonseed oil, sesame oil or corn oil.
Docosahexaenoic acid-containing fats and oils containing the antioxidant component of (1) and having a docosahexaenoic acid content of 2 to 30% by weight in all constituent fatty acids. 2. The method according to claim 1, wherein the fat or oil having a docosahexaenoic acid content of 10% by weight or more is one or more fats or oils selected from the group consisting of tuna oil, bonito oil, sardine oil, horse mackerel oil, mackerel oil, and squid oil. The docosahexaenoic acid-containing fat or oil according to claim 1, which is a concentrated docosahexaenoic acid fat or oil. 3. Concentrated fats and oils containing docosahexaenoic acid concentrated by a fractionation method without using a solvent, concentrated fats and oils by a fractionation method using a solvent, concentrated fats and oils using enzymes or microorganisms, or extraction using a supercritical gas. The docosahexaenoic acid-containing fat or oil according to claim 2, which is a concentrated fat or oil obtained by a method.