Composition of oils and fats containing polyunsaturated fatty acids

Abstract

The object of the present invention is to provide a polyunsaturated fatty acid-containing oil composition that has reduced interfacial tension with respect to water and good oxidative stability. [Solution] A polyunsaturated fatty acid-containing oil composition containing 5% by mass or more of polyunsaturated fatty acid-containing oil derived from algae, and having an interfacial tension X of 27 mN / m or less. However, the interfacial tension is the interfacial tension with water at 20°C, and the interfacial tension X is the interfacial tension 10,500 msec after the interface has formed.

Description

Technical Field

[0001] The present invention relates to a polyunsaturated fatty acid-containing oil and fat composition.

Background Art

[0002] In recent years, it has become known that polyunsaturated fatty acid-containing oils and fats represented by DHA (docosahexaenoic acid) and EPA (eicosapentaenoic acid) have physiological effects, and from a health-conscious perspective, polyunsaturated fatty acid-containing oil and fat compositions comprising polyunsaturated fatty acid-containing oils and fats are not limited to health foods and the like, and are also widely used for addition to general foods. However, since polyunsaturated fatty acid-containing oils and fats have the problem of extremely poor oxidation stability, various methods for improving oxidation stability have been disclosed (Patent Document 1 to Patent Document 3).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of Invention

Problem to be Solved by the Invention

[0004] The applicant has proposed methods for improving oxidation stability in Patent Documents 1 to 3. The present inventor considered that imparting additional functionality is necessary to further expand the use of polyunsaturated fatty acid-containing oil and fat compositions.

[0005] The inventors investigated the functions required of polyunsaturated fatty acid-containing oil and fat compositions. Since polyunsaturated fatty acid-containing oil and fat compositions are often used by adding small amounts to foods containing moisture, it was recognized that it is important to improve the compatibility of the polyunsaturated fatty acid-containing oil and fat composition with foods containing moisture. Furthermore, it was recognized that reducing the surface tension of the polyunsaturated fatty acid-containing oil and fat composition with respect to water is effective in improving compatibility with foods containing moisture, and this was identified as a new challenge.

[0006] Therefore, an object of the present invention is to provide a polyunsaturated fatty acid-containing oil composition that has reduced interfacial tension with respect to water and good oxidative stability. [Means for solving the problem]

[0007] The inventors of this invention have achieved a reduction in the interfacial tension of the polyunsaturated fatty acid-containing oil composition with respect to water by incorporating a specific amount of polyunsaturated fatty acid-containing oil derived from algae, thereby completing the present invention.

[0008] In other words, the present invention includes the following: (1) A polyunsaturated fatty acid-containing oil composition containing 5% by mass or more of polyunsaturated fatty acid-containing oil derived from algae, and having an interfacial tension X of 27 mN / m or less. However, the interfacial tension is the interfacial tension with water at 20°C, and the interfacial tension X is the interfacial tension 10,500 msec after the interface has formed. (2) The polyunsaturated fatty acid-containing oil composition of (1), wherein the rate of decrease in interfacial tension is 0.00004 mN / m·msec or more. However, the interfacial tension is the interfacial tension with water at 20°C, where interfacial tension X is the interfacial tension 10500 msec after interface formation, interfacial tension Y is the interfacial tension 500 msec after interface formation, and the rate of decrease in interfacial tension is the absolute value of (XY) / (10500-500). (3) A polyunsaturated fatty acid-containing oil composition according to (1) or (2), wherein the CDM stability time measured at 96°C is 2 hours or more. (4) A food product containing the polyunsaturated fatty acid-containing oil composition of (1) or (2). (5) A food product containing the polyunsaturated fatty acid-containing oil composition of (3). [Effects of the Invention]

[0009] The present invention provides a polyunsaturated fatty acid-containing oil composition that achieves a reduction in interfacial tension with respect to water and has good oxidative stability. [Modes for carrying out the invention]

[0010] The present invention will be described in detail below. In this specification, the "~" symbol indicating a numerical range means a value greater than or equal to a predetermined number (lower limit of the numerical range) and less than or equal to a predetermined number (upper limit of the numerical range). Furthermore, when upper and lower limits are indicated for a numerical range, these limits may be combined as appropriate, and the resulting numerical range will also be disclosed.

[0011] In this specification, a polyunsaturated fatty acid-containing oil composition includes long-chain polyunsaturated fatty acids having five or more double bonds and 20 or more carbon atoms. The type of fatty acid having five or more double bonds is not particularly limited, but docosahexaenoic acid (DHA; C22:6), eicosapentaenoic acid (EPA; C20:5), and docosapentaenoic acid (DPA; C22:5) are examples. Embodiments including various animal and vegetable oils such as fish oil and vegetable oils, and oils obtained from microorganisms and algae are also examples.

[0012] The polyunsaturated fatty acid-containing oil composition of the present invention contains polyunsaturated fatty acid-containing oil derived from algae as an essential component. Polyunsaturated fatty acid-containing oil derived from algae refers to oil extracted from microalgae. Microalgae are expected to be a next-generation source of oil due to their high oil production capacity, and some microalgae are known to be high in DHA and EPA, attracting attention as a new source of DHA and EPA.

[0013] The polyunsaturated fatty acid-containing oil composition of the present invention contains 5% by mass or more of polyunsaturated fatty acid-containing oil derived from algae. Preferably, it is 5% to 100% by mass. More preferable lower limits of content are 6%, 7%, 8%, 9%, and even more preferably 10% by mass. More preferable upper limits of content are 95%, 90%, 85%, 80%, 75%, and even more preferably 70% by mass. By including an appropriate amount of polyunsaturated fatty acid-containing oil derived from algae, the interfacial tension of the polyunsaturated fatty acid-containing oil composition with respect to water can be reduced. If the content of polyunsaturated fatty acid-containing oil derived from algae is less than 5% by mass, the interfacial tension of the polyunsaturated fatty acid-containing oil composition with respect to water may not be reduced.

[0014] In this specification, interfacial tension refers to the interfacial tension with water at 20°C, and the interfacial tension is measured using a contact angle meter by the pendant drop method. Interfacial tension can be measured, for example, using a contact angle meter DMs-401 (manufactured by Kyowa Interfacial Science Co., Ltd.).

[0015] The polyunsaturated fatty acid-containing oil composition of the present invention has an interfacial tension of 27 mN / m or less, where X is the interfacial tension 10,500 msec after interface formation and Y is the interfacial tension 500 msec after interface formation. A preferred interfacial tension X is 10 to 27 mN / m. More preferred lower limits for interfacial tension X are 11 mN / m, 12 mN / m, 13 mN / m, and 14 mN / m. More preferred upper limits for interfacial tension X are 26.5 mN / m, 26 mN / m, 25.5 mN / m, and 25 mN / m. By keeping the interfacial tension X within an appropriate range, the interfacial tension of the polyunsaturated fatty acid-containing oil composition with respect to water can be reduced, improving its compatibility with water. In a preferred embodiment, the rate of decrease in interfacial tension, obtained as the absolute value of (XY) / (10500-500), is 0.00004 mN / m·msec or higher, and a more preferred rate of decrease in interfacial tension is 0.00004 to 0.0003 mN / m·msec. Even more preferred lower limits for the rate of decrease in interfacial tension are 0.000045 mN / m·msec and 0.00005 mN / m·msec. Even more preferred upper limits for the rate of decrease in interfacial tension are 0.00025 mN / m·msec and 0.0002 mN / m·msec. By keeping the rate of decrease in interfacial tension within an appropriate range, a greater decrease in the interfacial tension of the polyunsaturated fatty acid-containing oil composition with respect to water can be achieved, and the rate of compatibility between the polyunsaturated fatty acid-containing oil composition and water can be improved.

[0016] CDM (Conductmetric Determination Method) stability is a value that indicates the oxidative stability of oils and fats. In this specification, the value obtained by the CDM stability test is referred to as "CDM stability time" and is used as an indicator for evaluating oxidative stability. The longer the CDM stability time, the better the oxidative stability. In this specification, the method for the CDM stability test is a modified version of the standard oil and fat analysis test method 2.5.1.2-1996, in which clean air is introduced while the oil and fat are heated to 96°C in a reaction vessel, and volatile decomposition products generated by oxidation are collected in water, and the conductivity of the water is continuously measured. The time until the inflection point where the value changes rapidly indicates the "CDM stability time".

[0017] In a preferred embodiment, the polyunsaturated fatty acid-containing oil and fat composition of the present invention has a CDM stability time of 2 hours or more. More preferably, the CDM stability time is 2 to 20 hours. Even more preferably, the lower limit of the CDM stability time is 2.5 hours, 3 hours, 3.5 hours, and 4 hours. Even more preferably, the upper limit of the CDM stability time is 19 hours, 18 hours, 17 hours, 16 hours, and 16.5 hours. By setting the CDM stability time within an appropriate range, a polyunsaturated fatty acid-containing oil and fat composition with superior oxidation stability can be obtained.

[0018] As long as the above configuration is satisfied, various fats and oils can be used in the polyunsaturated fatty acid-containing fat and oil composition of the present invention without limitation. The usable fats and oils are exemplified below. Vegetable fats and oils such as soybean oil, high erucic acid rapeseed oil, rapeseed oil, corn oil, cottonseed oil, peanut oil, sunflower oil, high oleic sunflower oil, rice bran oil, safflower oil, high oleic safflower oil, olive oil, sesame oil, palm oil, coconut oil, palm kernel oil, shea butter, sal fat, cocoa butter, animal fats and oils such as milk fat, beef tallow, lard, medium-chain fatty acid-bound fats and oils (MCT), fats and oils derived from microbial fermentation, as well as their hydrogenated oils, fractionated oils, hydrogenated fractionated oils, fractionated hydrogenated oils, processed fats and oils subjected to transesterification and the like, and one or two or more selected from these can be used. Preferred fats and oils for use in the polyunsaturated fatty acid-containing fat and oil composition of the present invention are soybean oil, high erucic acid rapeseed oil, rapeseed oil, corn oil, cottonseed oil, peanut oil, sunflower oil, high oleic sunflower oil, rice bran oil, safflower oil, high oleic safflower oil, olive oil, sesame oil, and palm fractionated oil. More preferred are soybean oil, rapeseed oil, corn oil, cottonseed oil, sunflower oil, high oleic sunflower oil, rice bran oil, safflower oil, high oleic safflower oil, olive oil, and low-melting point fraction of palm oil, which may be the fats and oils subjected to the aforementioned processing, and one or two or more selected from these can be used.

[0019] In a preferred embodiment, the polyunsaturated fatty acid-containing fat and oil composition of the present invention can be used by adding a small amount to water-containing foods. Examples of water-containing foods include foods containing water in their food components, such as vegetables, prepared side dishes, and fruits. In some embodiments, various forms mainly composed of water, such as liquid foods such as soups, beverages such as smoothies, and desserts such as yogurt, can be exemplified. Since the polyunsaturated fatty acid-containing fat and oil composition of the present invention can achieve the effect of improving the oil compatibility with water-containing foods, it is preferably used for foods having an exposed aqueous phase on the surface. Examples of foods having an exposed aqueous phase on the surface include vegetables, and the mode of use as a dressing for vegetables can be exemplified. Moreover, the use as a seasoning liquid or a flavoring agent in liquid foods such as soups can be exemplified.

Examples

[0020] Examples of the present invention are shown below to describe the present invention in more detail. In addition, in the examples, "%" and "part(s)" both mean mass-based standards.

[0021] 〇Analysis Methods [Analysis Method for Fatty Acid Composition] The fatty acid composition of fats and oils was measured by preparing fatty acid methyl esters in accordance with the method specified in "Standard Methods for the Analysis of Fats, Oils and Related Materials 2.4.1.2 Methyl Esterification Method (Boron Trifluoride Methanol Method)" established by the Japan Oil Chemists' Society, and performing the measurement in accordance with "Standard Methods for the Analysis of Fats, Oils and Related Materials 2.4.2.3 Fatty Acid Composition (Capillary Gas Chromatography Method)" established by the Japan Oil Chemists' Society. [Method for Measuring Interfacial Tension and Method for Calculating Decrease Rate of Interfacial Tension] The interfacial tension over time was measured by the pendant drop method. Fats and oils temperature-controlled at 20°C were discharged into ion-exchanged water temperature-controlled at 20°C to form droplets. Using a contact angle meter (DropMaster series DMs-401 manufactured by Kyowa Interface Science Co., Ltd.), measurements were taken every 5000 msec starting from 500 msec after droplet formation. Separately, the interfacial tension was obtained by the Young-Laplace method from the density difference between the two liquids at 20°C. From the obtained interfacial tension values, interfacial tension X is defined as the interfacial tension at 10500 msec after interface formation, interfacial tension Y is defined as the interfacial tension at 500 msec after interface formation, and the decrease rate of interfacial tension was obtained from the absolute value of (X-Y) / (10500-500). [Analysis Method for CDM Stability Time] The CDM test method in the "Stability Test" of Standard Methods for the Analysis of Fats, Oils and Related Materials (2.5.1.2-1996) was partially modified, and clean air was blown into the reaction vessel while the sample was heated at 96°C. Volatile decomposition products generated by oxidation were collected in water, and the time until the inflection point where the conductivity of water changes sharply was measured, and the fats and oils were evaluated as the CDM stability time.

[0022] 〇Fats and Oils Used 〇Fish Oil DHA-27 (manufactured by Tama Biochemical Co., Ltd.) was used as the polyunsaturated fatty acid-containing oil derived from fish oil. 〇Algae oil For the polyunsaturated fatty acid-containing oil derived from algae, we used algal oil life's Omega60 (manufactured by DSM). 〇Soybean oil Soybean oil (manufactured by Fuji Oil Co., Ltd.) was used.

[0023] Preparation of polyunsaturated fatty acid-containing oil and fat compositions The aforementioned fish oil, algae oil, and soybean oil were mixed in the proportions shown in Table 1 below and used for the following studies.

[0024] [Table 1]

[0025] Composition of fatty acids in a polyunsaturated fatty acid-containing oil composition The results of analyzing the prepared polyunsaturated fatty acid-containing oil composition according to the [Analysis Method for Fatty Acid Composition] are shown in Table 2. In Table 2, the number following "C" indicates the number of carbon atoms, and the number to the right of ":" indicates the number of double bonds. For saturated fatty acids that do not have double bonds, the information after ":" has been omitted.

[0026] [Table 2]

[0027] ○ Interfacial tension of oil and fat compositions containing polyunsaturated fatty acids The obtained polyunsaturated fatty acid-containing oil composition was analyzed according to the [method for measuring interfacial tension and method for calculating the rate of decrease in interfacial tension] described above. Table 3 shows the interfacial tension X at 10,500 msec after interface formation, the interfacial tension Y at 500 msec after interface formation, and the absolute value of (XY) / (10,500-500) as the rate of decrease in interfacial tension.

[0028] 〇 Oxidative stability of polyunsaturated fatty acid-containing oil composition The results of the analysis of the obtained polyunsaturated fatty acid-containing oil composition according to the [CDM stability time analysis method] described above are shown in Table 3.

[0029] [Table 3]

[0030] Discussion of Table 3 The polyunsaturated fatty acid-containing oil compositions of Examples 1-6 had a surface tension X of 27 mN / m or less. This value was better than that of soybean oil in Reference Example 1. The polyunsaturated fatty acid-containing oil compositions of Examples 1 to 6 yielded good results, satisfying a rate of decrease in surface tension of 0.00004 mN / m nN / m·msec or higher. The polyunsaturated fatty acid-containing oil compositions of Examples 1 to 6 had a CDM stability time of 2 hours or more, demonstrating better oxidative stability than Comparative Example 1. [Industrial applicability]

[0031] The present invention provides a polyunsaturated fatty acid-containing oil composition that achieves a reduction in interfacial tension with respect to water and has good oxidative stability.

Claims

1. A polyunsaturated fatty acid-containing oil composition containing 5% by mass or more of polyunsaturated fatty acid-containing oil derived from algae, and having an interfacial tension X of 27 mN / m or less. However, the interfacial tension is the interfacial tension with water at 20°C, and the interfacial tension X is the interfacial tension 10,500 msec after the interface has formed.

2. The polyunsaturated fatty acid-containing oil composition according to claim 1, wherein the rate of decrease in interfacial tension is 0.00004 mN / m·msec or more. However, the interfacial tension is the interfacial tension with water at 20°C, where interfacial tension X is the interfacial tension 10500 msec after interface formation, interfacial tension Y is the interfacial tension 500 msec after interface formation, and the rate of decrease in interfacial tension is the absolute value of (X - Y) / (10500 - 500).

3. The polyunsaturated fatty acid-containing oil composition according to claim 1 or claim 2, wherein the CDM stability time measured at 96°C is 2 hours or more.

4. A food product containing the polyunsaturated fatty acid-containing oil composition described in claim 1 or claim 2.

5. A food product containing the polyunsaturated fatty acid-containing oil composition described in claim 3.

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