JPH0657287A - Method for stabilizing orbital oil - Google Patents

Abstract

PURPOSE:To improve the oxidation resistance of an orbital oil of fish and enable the utilization of the oil as an excellent food material contg. an increased amt. of DHA by reacting the oil with cyclodextrin. CONSTITUTION:An orbital oil which is obtd. by extraction while minimizing the generation of peroxides is deodorized to give a purified orbital oil, which is reacted with cyclodextrin. Cyclodextrin, a substance formed by bonding glucose through alpha-1,4 bond into a ring, includes compds. having 6 (alpha-type), 7 (beta-type), 8 (gamma-type), or more glucose units. The reaction with cyclodextrin improves the resistances to heat, light, and oxygen of the oil and converts the oil from a liq. to a powder, facilitating handling. The obtd. powder is pref. microcapsuled to further enhance the oxidation resistance.

Description

Detailed Description of the Invention

[0001]

The present invention relates to a crude refined oil of fish orbital oil which characteristically contains a large amount of docosahexaenoic acid (hereinafter abbreviated as DHA), its refined fish orbital oil or its fatty acid, fatty acid ester, or fatty acid amide ( Hereinafter, these are collectively referred to as orbital oils.) A method for stabilizing orbital oils by reacting them with cyclodextrin, and further by encapsulating the powdered orbital oil thus obtained It includes methods to stabilize orbital oils against heat, light and oxygen.

[0002]

2. Description of the Related Art DHA is icosapentaenoic acid (hereinafter referred to as EP
Abbreviated as A. It is known that it is effective for the prevention and treatment of thrombosis as well as), but recently it was also confirmed that DHA is effective for central nervous system diseases such as improvement of brain function and suppression of visual loss. ing. As described above, DHA having an extremely important physiologically active action exists abundantly only in fish and shellfish, and there is no method other than ingestion of fish and shellfish for supplementing DHA. Among fish oils, sardine oil and cod liver oil are generally widely used, and are mainly used as hydrogenated oils as raw materials for margarine and shortening, as concentrated EPAs as health supplements, and as feed oils for fish feed. ing. However, with these fish oils D
HA content is about 5-12%, EP rather than DHA
Since A is more contained (about 12 to 20%), DHA
It is not possible to obtain a so-called DHA oil containing a high concentration of. At such a time, in 1990, it was revealed by Yazawa et al. That DHA was contained at a high concentration in the orbital adipose tissue existing around the eyes in large blue-backed fish such as tuna and bonito.

[0003]

The orbital oil extracted from the orbital fat has a fatty acid composition greatly different from that of ordinary fish oil.
HA is contained at a high concentration of 25 to 40%. Part of the heads of tuna and bonito are used as fish meal, but most of them have been discarded so far and remain unused resources. DHA with orbital oil of tuna and bonito
The use as a raw material is very advantageous from the viewpoint of already high purity of DHA and effective use of waste. However, the orbital oil also contains a large amount of highly unsaturated fatty acids such as DHA and EPA (5 to 8%) as well as fish oil, and thus peroxides are easily generated, and storage thereof is a difficult problem. .

Tocopherol, which is widely used as a food additive, is generally used as a means for preventing the oxidation of fish oil, but its antioxidant effect is not sufficient. In addition, synthetic antioxidants such as dibutylhydroxytoluene (BHT), butylhydroxyanisole (BHA), and ethoxyquin are said to have superior antioxidant effects to tocopherol, and are used in feed fish oil for fish feed.
It cannot be used in edible oils and fats because it is considered to be a safety hazard to the human body. As described above, no natural antioxidant effective in preventing the oxidation of edible fish oil has been found so far.

[0005]

Means for Solving the Problems The inventors of the present invention have conducted extensive studies on the above-mentioned antioxidant method of fish oil without using antioxidant, and as a result, reacted fish oil and orbital oil with cyclodextrin. In this case, it is stable against heat, light and oxygen, and it has been found that the use of this reaction agent makes the liquid oil powdery and thus easy to handle, and has a wide range of uses as a food material. completed. That is, the present invention provides a method for stabilizing fish orbital oils, which comprises reacting purified orbital oil obtained by deodorizing and refining orbital oil extracted by suppressing the formation of peroxides as much as possible, with cyclodextrin. It was developed. The cyclodextrin used in the present invention is a substance in which glucose is cyclically bound by α-1,4 bonds, and 6 (α-type), 7 (β-type),
Eight (γ-type) or more may be combined.

Further, it is necessary to pay close attention to the fact that oxidation does not proceed during the inclusion, and inclusion treatment in an inert gas such as N ₂ gas or inclusion treatment at a lower temperature for a short time is required. However, specifically, it is carried out as described in the following examples. It is highly desirable to further protect the orbital oil powder obtained here by using a microencapsulation technique because a further antioxidant effect can be expected. As a microencapsulation technique in this case, a mechanical and physical dark technique such as a spray drying method is preferable, but various microencapsulation techniques such as a chemical technique such as an orifice method and a physical technique such as a phase separation method are also available. Applicable.
It can also be protected with a large capsule such as a gelatin capsule. As described above, according to the present invention, a method for utilizing fish orbital oils containing a high concentration of DHA, which is expected to have an effect of improving brain function and an effect of suppressing a decrease in visual acuity, as an excellent food material has been developed.

[0007]

EXAMPLES Next, the examples will be described more specifically. Example 1 Orbital adipose tissue was removed from the head of bigeye tuna and crushed with a meat chopper until the adipose tissue became a paste. Five times the amount of acetone was added to this to dissolve the oil and remove insoluble substances such as proteins to obtain an orbital oil extraction acetone solution. Separately, 24 ml of an aqueous solution in which 0.4 g of β-cyclodextrin was dissolved was prepared, 1.2 ml of the above acetone solution extracted with orbital oil was added, and the mixture was stirred at 10 ° C for 3 hours in a N ₂ gas stream. The formed precipitate was separated by filtration, dried, washed with ether and further dried to obtain a reaction product. This reaction product and the above raw material orbital oil were kept in a chamber at 50 ° C. equipped with a fluorescent lamp, and the peroxide value thereof was measured with the lapse of time, and the result is shown by the curve of + mark in the figure.

Comparative Example 1 The peroxide value of the reaction product hardly increased over a long period of time, whereas the peroxide value of the control product of the present invention which was not treated with β-cyclodextrin rapidly increased. (□ in the figure
Significantly, the reaction product with cyclodextrin is much more stable to heat, light and oxygen.

Example 2, Comparative Example 2 The acetone solution extracted from orbital oil prepared in Example 1 was -30 ° C.
Orbital oil (DH)
A35.4%, EPA8.1%) 100 g was obtained. This was added to water-containing ethanol together with 40 g of β-cyclodextrin, stirred at high speed, then rapidly cooled with liquid nitrogen gas and freeze-dried. The reaction product thus obtained was further placed in a gelatin soft capsule with a diameter of 10 mm by the plate method and allowed to stand at room temperature, and compared with an untreated control product, the inclusion compound had a peroxide value of 28 (meq / kg). Oxidation progressed to
The reaction product according to the present invention was suppressed to 1.6 (meq / kg). (Indicated by ◇ and △ respectively)

Example 3, Comparative Example 3 To 1 kg of extracted orbital oil obtained by concentrating the acetone solution extracted from orbital oil prepared in Example 1 with an evaporator, 4 times amount of caustic ethanol solution was added and stirred at room temperature for 3 hours. Then, the reaction solution was washed with a large amount of water to obtain a fatty acid ethyl ester. This was purified by distillation under reduced pressure and urea fractionation to obtain 41 g of 75% DHA ethyl ester concentrate. To this, 5 times the amount of acetone was added and dissolved, and an aqueous solution of a mixture of α, β and γ-cyclodextrin was added, and the mixture was stirred in a nitrogen gas stream for 3 hours. The formed precipitate was filtered off, dried, washed with ether and further dried to obtain a reaction product. When this reaction product was allowed to stand at room temperature, it had a POV of 38 (meq / kg) after 10 days, but was superior in antioxidant property to the untreated control product of 476 (meq / kg).

Example 4, Comparative Example 4 An equal mixture of gelatin and arabic gum was gradually dissolved with stirring to give an aqueous solution of 0.5 to 3.0 (w / v). The orbital oil cyclodextrin inclusion compound prepared in Example 1 was gradually added to this with stirring with a homomixer equipped with a jet type rotator to obtain a suspension in which particles were uniformly dispersed. The suspension was constantly stirred and fed by a metering pump onto the rotary disk of a small commercial spray-dry granulator. The feed rate is 50 ml / min and the drying chamber inlet temperature is 1
The temperature was 50 ° C and the exhaust temperature was 60 ° C. The powdery microcapsules thus obtained were immediately cooled and allowed to stand in a chamber at 50 ° C. equipped with a fluorescent lamp, and their peroxide value was measured over time while comparing with the raw orbital oil.

The results are shown by the curves of □ and X in the figure. The peroxide value of the microencapsulated sample did not increase over a long period of time, whereas the orbital oil of the control product rapidly increased the peroxide value. Also, as compared with Example 1, it can be seen that the present method has less oxidation than the one simply encapsulating with cyclodextrin. (+ Mark and X mark respectively)

[0013]

INDUSTRIAL APPLICABILITY As described above, according to the present invention, fish orbital oils containing a high concentration of DHA, which is expected to have an effect of improving brain function and an effect of suppressing a decrease in visual acuity, are included in cyclodextrin as inclusion powder, By encapsulating with gelatin or arabic rubber, the problem of stability against oxidation, which has been a big problem in the past, can be solved. As a result, we have developed a method that can be used as a superior food material with enhanced DHA.

[Brief description of drawings]

FIG. 1 shows the results of an oxidative stability test of orbital oil, illustrating the relationship between the number of days and POV (meq / kg).

[Explanation of symbols]

□ Control orbital oil in Examples 1 and 4 + Cyclodextrin clathrate orbital oil in Example 1 ◇ Cyclodextrin clathrate orbital oil in Example 2 △ The cyclodextrin clathrate orbital oil in Example 2 was further gelatin-encapsulated. When the inclusion orbital oil in Example 4 was further microencapsulated with gelatin and gum arabic

Claims (7)

[Claims] 1. A method for stabilizing fish orbital oil, which comprises reacting fish orbital oil with cyclodextrin. 2. The method for stabilizing fish orbital oil according to claim 1, wherein the fish orbital oil uses orbital oil enriched with highly unsaturated fatty acids. 3. The method for stabilizing fish orbital oil according to claim 1, wherein the fish orbital oil is a residual orbital oil produced when refining the orbital oil concentrated with a polyunsaturated fatty acid. 4. The method for stabilizing fish orbital oil according to claim 1, wherein the fish orbital oil is a fatty acid of the orbital oil whose iodine value is increased by refining. 5. The method for stabilizing fish orbital oil according to claim 1, wherein the fish orbital oil is a fatty acid ester of orbital oil whose iodine value is increased by refining. 6. The method for stabilizing fish orbital oil according to claim 1, wherein the fish orbital oil is a fatty acid amide of orbital oil whose iodine value is increased by refining. 7. Fish orbital oil, cyclodextrin,
The method for stabilizing fish orbital oil according to claim 1, wherein the reaction product is further encapsulated.