JP3346793B2 - Method for deodorizing fish oil and fish oil-containing food - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for deodorizing fish oil and a food containing fish oil obtained by the method.

[0002]

2. Description of the Related Art Fish oils contain ω-3 polyunsaturated fatty acids (eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA)), whose physiological actions have recently attracted attention.
It is expected that daily intake of this will lead to prevention of adult diseases. However, unrefined fish oil, which has only been squeezed, contains amines, fatty acids, and carbonyl compounds, which exhibit a unique fishy odor and limit its use as an edible oil.

[0003] Therefore, as means practically generally used for deodorizing purposes, there are vacuum steam distillation and molecular distillation.
Various devices, conditions and ancillary means have been used to efficiently remove odorous components.

[0004]

However, although the deodorized fish oil thus obtained is almost tasteless and odorless immediately after purification, odorous components are generated again during the storage period, and a so-called return odor is generated. Therefore, it cannot be used for oil-and-fat-containing foods that require a long distribution storage period. The cause of this return odor is that non-volatile amines and carbonyl compounds which cannot be completely removed by distillation or the like generate odorous components over time. Since both of these amines and carbonyl compounds have polar groups, they can be adsorbed and removed using an inorganic adsorbent such as silica gel, alumina, magnesium silicate and the like.

However, it is difficult to recycle the inorganic adsorbent, and it is troublesome to dispose each time, resulting in high cost. Moreover, the fish oil to be treated contains polyunsaturated fatty acids, and is liable to cause peroxidation of lipids due to the catalytic action of the metal in the inorganic adsorbent. The present inventor has continued his intensive studies, and a group of polar compounds, which are precursors of these odorous components, is obtained by absorbing and removing fish oil using a porous polymer resin.
It was discovered that the odor did not return during the subsequent storage period, and the present invention was completed.

[0006]

The first aspect of the present invention is a method for deodorizing fish oil, characterized in that fish oil is treated with a porous polymer resin to absorb and remove odor components. No. 2 is a fish oil-containing food, characterized by containing fish oil obtained by the deodorizing method of the present invention.

[0007] In the deodorizing method of the present invention, preferably, the fish oil purified through the usual deacidification, decolorization, and deodorization (vacuum steam distillation) steps is reduced by 10 to 50%, preferably 20 to 30%.
The non-polar organic solvent is dissolved so as to have a% concentration. Here, as the nonpolar organic solvent, preferably, a hydrocarbon solvent such as n-hexane, petroleum ether, cyclohexane, and toluene is used. Next, this solution is passed through a column filled with a high-polarity or medium-polarity porous polymer resin, and the polar compound group is adsorbed on the resin. After the completion of the passage, the eluted solution is concentrated and subjected to vacuum steam distillation to obtain a highly purified tasteless and odorless fish oil.

The used resin does not require regeneration with an acid or a base, and can be repeatedly used simply by regenerating and washing with a polar solvent such as methanol or acetone. Examples of the high-polarity porous polymer resin used in the present invention include Amberlite XAD-11 and XAD-1
2 can be preferably used. As the medium-polarity porous polymer resin, Amberlite XAD
-7, XAD-8 and HP-2MG (manufactured by Mitsubishi Kasei Co., Ltd.) can be preferably used.

[0009] The fish oil obtained by the deodorizing method of the present invention is an oil and fat from which precursors of odorous components have been removed without damaging its chemical structure and which can withstand long-term storage.
It can be widely used for processed foods such as dressings, mayonnaise and margarine.

[0010]

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to Examples, but the scope of the present invention is not limited to the following Examples. (Example 1) Normal deacidification, decolorization, deodorization (vacuum steam distillation)
400 g of tuna oil refined through the process is n-hexane 2 L
And the solution was passed through a column packed with 200 ml of HP-2MG to remove the polar substances in the solution by adsorbing them on the resin. The fish oil was allowed to pass through the n-hexane solution as a non-adsorbed substance. After the passage, 200 ml of n-hexane was passed through the column to wash the resin. The flow-through solution and the washing solution were combined, concentrated under reduced pressure, and subjected to reduced pressure steam distillation to obtain 390 g of highly purified fish oil.

After completion of the passage of the resin and washing with n-hexane, the resin was passed through and washed with 800 ml of acetone, and then passed through 600 ml of n-hexane and the solvent was replaced to regenerate the resin. FIG. 1 shows the thin-layer chromatography of the fish oil obtained in this example. As can be seen from Fig. 1, raw fish oil (vacuum steam distilled and deodorized fish oil) has spots of polar impurities near the origin, but in highly refined fish oil, these spots have disappeared, and polar substances have been removed. Table 1 shows the results of measurement of nitrogen in the fish oil using a total nitrogen analyzer TN-05 (manufactured by Mitsubishi Kasei Corporation). According to this, the nitrogen content is significantly lower than that of the raw fish oil, and the effect of adsorbing and removing amines is recognized.

[0012]

[Table 1]

Next, the generation of fishy odor was observed for the re-deodorized product of the highly refined fish oil and the raw fish oil (normal vacuum steam distilled product). 50 g of each sample was placed in a 100 ml sample bottle and sealed, and the degree of odor generation was observed with time at room temperature. Table 2 shows the results.

[0014]

[Table 2]

(Example 2) Highly refined fish oil 42 obtained in Example 1
g, egg yolk 7 g, vinegar 5.5 g, and water 41.3 g were stirred and emulsified using a blender, and the mixture was reconstituted with 0.4 g, corn starch.
2.7 g and 1.1 g of common salt were added, and the mixture was further stirred and mixed to obtain 100 g of a fish oil-containing salad dressing. (Example 3) Steamed red tuna meat at 105 ° C for 30 minutes, put 85g of appropriately cut into a can for can having a diameter of 7cm and a height of 3.6cm, and added 50g of highly purified fish oil obtained in Example 1 After that, it is sealed using a vacuum winder,
The mixture was sterilized under pressure and heat for 5 minutes to make canned tuna oil.

[0016]

According to the present invention, it is possible to provide a fish oil which hardly causes fish odor even after long-term storage, and the fish oil according to the present invention can be widely used as an oil / fat-containing food.

[Brief description of the drawings]

FIG. 1 shows thin layer chromatography of fish oil.

Continuation of the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) C11B 3/10 A23L 1/015 A23L 1/24 A23L 1/325

Claims (2)

(57) [Claims] 1. A method for deodorizing fish oil, comprising treating fish oil with a medium-polarity porous polymer resin adsorbent and a non-polar solvent to adsorb and remove odor components. 2. A fish oil-containing food, comprising the fish oil obtained by the deodorizing method according to claim 1.