JPH0860177A - Method for deodorizing oil fat or of marine animal - Google Patents

Abstract

PURPOSE: To provide the method for simply and efficiently deodorizing the oil or fat of a marine animal into the purified product little in the production of its characteristic 'fishy smell' during storage. CONSTITUTION: The method for deodorizing the oil or fat of a marine animal, such as a fish oil, comprises bubbling the oil or fat preliminarily treated through a deoxidizing process and a decoloring process with an oxygen-containing gas such as air and subsequently subjecting the treated fat or oil to a vacuum steam distillation. The condition of the aeration comprises aerating at an oxygen flow rate of 5-20ml/min per kg of the fish oil at 15-60 deg.C for 1-150hrs.

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 aquatic animal fats and oils useful as foods or pharmaceuticals.

[0002]

BACKGROUND OF THE INVENTION Marine animal fats and oils, especially fish oils, contain a large amount of highly unsaturated fatty acids (hereinafter abbreviated as PUFA), and among them, eicosapentaenoic acid (hereinafter abbreviated as EPA) and docosahexaenoic acid (hereinafter DHA). Has been known to exert various beneficial physiological functions in the living body, and research on advanced purification techniques for effectively utilizing these in physiological applications is underway.

In general, crude crude oil before refining aquatic animal fats and oils contains various components such as free fatty acids, odorants, coloring substances, proteins, phosphatides and sterins as impurities other than glycerides. . Therefore, in order to remove these impurities, a series of purification steps such as a degumming step, a deoxidizing step, a decoloring step, and a deodorizing step are performed.

When such a refining is carried out, the glyceride containing a polyunsaturated fatty acid, out of the glyceride which is the main component of fats and oils, is easily oxidized, so that oxygen has been kept out of contact with fats and oils during the refining process as much as possible. .

On the other hand, in the final step of refining fats and oils, deodorization is carried out to remove odorous components dissolved in the oil to produce a more edible edible oil. The odorous components that have a bad effect on the flavor of fats and oils vary depending on the type of fats and oils. And the like.

[0006] As a deodorizing step for removing such odorous components, vacuum steam distillation is usually adopted, whereby odorous components having relatively low molecular weight and higher volatility than glycerides are removed. There are also odorous components that are removed by thermal decomposition. Immediately after deodorization, the fats and oils have almost no odor and have a good flavor.

[0007]

However, when the above-mentioned deodorizing operation is performed on aquatic animal fats and oils containing a large amount of PUFA, for example, fish oil, the flavor is good immediately after, but glycerides are formed during storage. There is a problem that not only the odor originating from the oxidation of PUFA but also the odor peculiar to fish oil, that is, the so-called "raw odor" is generated, and the commercial value as edible oil and fat is reduced.

As a cause of generating such a peculiar odor, since the precursor of the odor component cannot be completely removed only by the conventional deodorizing step, such a trace component is changed into an odor component during storage, It is believed that it is combined with the odor due to the oxidation of the double bond of PUFA to produce a fishy taste.

Further, PUFA is thermally polymerized in a high-temperature deodorizing step, that is, the double bond portion is damaged and its content is apt to decrease. Therefore, the step of deodorizing fats and oils containing much PUFA, such as fish oil, is performed at a temperature slightly lower than that of fats and oils not containing much PUFA, so that the efficiency of removing odorous components naturally lowers. It is considered that the fats and oils that have undergone such a deodorizing step generate an odor during storage by combining the odor derived from the above-mentioned oxidation of PUFA and a changed precursor.

In particular, at the low peroxide value (POV) stage where it is considered that the oxidation of oil has not progressed so much,
Already a fishy taste. At this stage, it is considered that other odorous precursors than PUFA oxidation are the main cause.

Therefore, an object of the present invention is to solve the above-mentioned problems and provide a deodorizing method for obtaining fats and oils which are less likely to give rise to a characteristic "raw odor" during storage of aquatic animal fats and oils. A simple deodorizing method is to use a simple and efficient method for refining fats and oils.

[0012]

Means for Solving the Problems As a result of repeated studies on a method for efficiently deodorizing aquatic animal fats and oils, the inventor of the present invention has an oxygen-containing content The inventors have found that the deodorization efficiency of oils and fats is dramatically improved by passing a gas through it and then vacuum distillation is performed, and the generation of odors of the oils and fats stored after deodorization can be suppressed, and the present invention has been completed.

That is, in order to solve the above-mentioned problems, the means adopted in the present invention is to ventilate a marine animal fat and oil with a gas containing oxygen, and then carry out reduced pressure steam distillation.

Alternatively, a means for aerating a marine animal fat and oil that has undergone the deoxidizing step and the decolorizing step with an oxygen-containing gas and then performing vacuum steam distillation is adopted.

Further, in the above method for deodorizing aquatic animal fats and oils, the aquatic animal fats and oils are fish oils, and 1 kg of fish oil at 15 to 60 ° C. is aerated under conditions of aeration of an oxygen-containing gas of 5 to 20 ml / min of atmospheric oxygen. This means that the amount of ventilation is 1 to 150 hours.

The details will be described below. The marine animal fats and oils used in the present invention include fish oils made from fish such as bonito, tuna, and sardines, as well as marine animal fats and oils made from marine animals other than fish such as crustaceans and whales. Is.

The deodorizing method of the present invention is usually employed as one step in the step of refining fats and oils, and is usually performed on aquatic animal fats and oils that have undergone a deoxidizing step and a decolorizing step. In the deoxidation step, a method is generally used in which fats and oils are vigorously stirred with an aqueous sodium hydroxide solution to remove free fatty acids. In addition, the decolorizing step that is usually performed includes a method of decolorizing using an adsorbent such as activated clay.

The odorous components to be deodorized by aeration of oxygen-containing gas in the present invention are other than the polyunsaturated fatty acids contained in the above-mentioned marine animal fats and oils, and in addition to the components which themselves become odorous, Including those that change into odorous components due to chemical changes such as decomposition.

When deodorizing the above-mentioned aquatic animal oil by aeration of oxygen-containing gas, the fats and oils are kept at 15 to 60 ° C. This is because at a low temperature of less than 15 ° C, the action of oxygen on odorous components is not sufficiently exerted, and at a high temperature of more than 60 ° C, the oxidation of fats and oils remarkably progresses and the PUFA content decreases, which is not preferable.

The oxygen-containing gas used in the present invention can be employed without any particular limitation as long as it can ensure the safety in the production of fats and oils and in food hygiene.
As such an oxygen-containing mixed gas, for example, air can be adopted, or, of course, a gas prepared by mixing oxygen with an inert gas such as nitrogen gas may be adopted.

The aeration amount of such oxygen-containing gas is 5 to 20 in terms of oxygen amount at atmospheric pressure for 1 kg of marine animal fats and oils.
ml / min. Therefore, when air is used as the oxygen-containing gas, the air flow rate is 25 to 100 ml.
/ Minute is required. It is necessary to adjust such an aeration amount so as to suppress damage due to the oxidation of the double bond of PUFA as much as possible, and the aeration amount varies depending on the type of fats and oils, temperature, and aeration time. Similarly, the aeration time varies depending on the type of fats and oils and the temperature, and it is difficult to unconditionally specify.

When fish oil is used as the aquatic animal oil and fat, it is preferable to aerate air (oxygen content is 20 ml / min) at a rate of 100 ml / min for 5 to 150 hours per 1 kg of fish oil at 15 ° C. 60 2 for 1kg of fish oil at ℃
1 to 5 ml of air (5 ml / min of oxygen) at a rate of 5 ml / min
Aeration for 30 hours is preferred.

As a more specific example, at 30 ° C., air is mixed with 3 kg of air at a rate of 36 ml / min for 1 kg of fish oil.
It is preferable to ventilate for 0 to 120 hours, and at 60 ° C,
Air is 2 to 8 at a rate of 36 ml / min for 1 kg of fish oil.
Aeration for a period of time is preferred.

The aeration according to the present invention can be carried out without any particular limitation on the aeration device and the aeration method as long as the oxygen-containing gas is dispersed throughout the predetermined amount of fat or oil to be deodorized. However, in the present invention, the oil and fat temperature is set to 15 to 60 ° C., and since the oil and fat has a relatively high viscosity, it is preferable to perform aeration with agitation in order to perform aeration efficiently.

[0025]

In the method for deodorizing aquatic animal fats and oils of the present invention, an oxygen-containing gas is allowed to pass through the fats and oils at a predetermined temperature, so that the double bond portion of glyceride is not substantially damaged. That is, fats and oils are contacted with oxygen so that the PUFA content does not decrease significantly.

At this time, the odorous components or their precursors that cannot be completely removed by ordinary deodorization are oxidized by oxygen and decomposed, or are transformed into unstable substances which are easily decomposed by heat. It is possible to remove them by vacuum steam distillation.

[0027]

【Example】

[Example 1] 400 g of bonito oil that had been deoxidized and decolorized was added to 5 parts.
The mixture was placed in a 00 ml Erlenmeyer flask and stirred at a fat and oil temperature of 30 ° C. while aerating air at 36 ml / min for 96 hours, and then deodorized by vacuum steam distillation at 215 ° C. for 1 hour.

DHA in the fatty acid composition of fats and oils after deodorization treatment
The content was measured by gas chromatography. 180 g of this fat and oil was put into a 200 ml beaker, the upper part was covered with a Petri dish, and stored at 30 ° C., and changes with time in the peroxide value and odor of the fat and oil were examined by a sensory test. D
Regarding the HA content and the peroxide value, the results are shown in Table 1.

Regarding the above sensory test, 3 adult males and 3 females
With people as panelists, ◎ mark: No fishy smell at all, ○ mark: Almost no fishy smell, △ mark: A little fishy smell,
The evaluation is made in four levels, that is, x indicates that a fishy odor is felt, and the results are shown in Table 2.

[0030]

[Table 1]

[0031]

[Table 2]

Example 2 A deodorizing treatment was carried out in the same manner as in Example 1 except that air was aerated at 36 ml / min for 6 hours at a fat and oil temperature of 60 ° C.
The changes in HA content, peroxide value and odor with time were examined, and the results are shown in Table 1 or Table 2.

[Example 3] Deodorization was carried out in the same manner as in Example 1 except that air was aerated at 100 ml / min for 96 hours at a fat and oil temperature of 15 ° C. The changes in peroxide value and odor with time were examined, and the results are shown in Table 1 or Table 2.

[Comparative Examples 1 to 3] In Example 1, except that air was not aerated (Comparative Example 1), except that air was aerated at 36 ml / min for 6 hours at a fat and oil temperature of 65 ° C. What was deodorized exactly as in Example 1 (Comparative Example 2), 100 ml of air at a fat and oil temperature of 10 ° C.
A deodorizing treatment was carried out in the same manner as in Example 1 (Comparative Example 3), except that the aeration was performed at a flow rate of 96 minutes per minute for each DHA content, peroxide value and odor. The results were examined and the results are summarized in Table 1 or 2.

As is clear from the results of Tables 1 and 2, Comparative Example 1 in which the aeration step was not adopted, or Comparative Example in which the oil and fat temperature during aeration was outside the predetermined temperature range (15 to 60 ° C.) In Nos. 2 and 3, "raw odor" was generated when the oil and fat was stored for 7 days or more.

On the other hand, in Examples 1 to 3 satisfying all the conditions for deodorization, the generation of "raw odor" was suppressed in spite of the increase in the peroxide value as in Comparative Examples 1 to 3. Was done.

[0037]

As described above, according to the present invention, the oxygen-containing gas is aerated through the marine animal fats and oils at the predetermined temperature, and further the reduced pressure steam distillation is performed. It is possible to obtain marine animal fats and oils with less generation of "." Moreover, since this deodorizing method is a relatively simple method of passing gas through contact, there is an advantage that it is a simple and efficient deodorizing method of oil and fat purification.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hiroshi Yamamoto 17 Uozakihama-cho, Higashinada-ku, Kobe City Ueda Oil Stock Company (72) Inventor Junko Motoyama 17 Uozakihama-cho, Higashinada-ku Kobe City Ueda Oil Stock Company (( 72) Inventor Yuki Momose 17 Uozakihama-cho, Higashinada-ku, Kobe City Ueda Oil Co., Ltd. (72) Inventor Norifumi Sato 7 Pappilla B101, 253 Ueto, Kawagoe City

Claims (3)

[Claims] 1. A method for deodorizing marine animal fats and oils, which comprises aerating an oxygen-containing gas into the marine animal fats and oils, and then performing vacuum steam distillation. 2. The method for deodorizing marine animal fats and oils according to claim 1, wherein the marine animal fats and oils to be deodorized are oils and fats that have undergone a deoxidizing step and a decolorizing step. 3. The aquatic animal oil and fat is fish oil, and
The aeration condition of the oxygen-containing gas to 1 kg of fish oil at 60 ° C. is 1 to 15 at an atmospheric flow rate of 5 to 20 ml / min of oxygen.
The method for deodorizing aquatic animal fats and oils according to claim 1 or 2, which is 0 hour.