JPH04202599A - Production of oil and fat having low cholesterol content - Google Patents

Abstract

PURPOSE:To efficiently, inexpensively and safely remove cholesterol while utilizing a conventional facilities by adding a fatty acid to a cholesterol- containing oil and fat and then adding an alkaline aqueous solution thereto and separating the mixture into an oil layer and soap layer and collecting the oil layer. CONSTITUTION:>=0.5% (preferably 1-5%) fatty acid such as palmitic acid, stearic acid, oleic acid or linoleic acid is added to a cholesterol-containing oil and fat such as fish oil, pig oil or cow oil and then an alkaline aqueous solution is preferably added thereto, preferably at an amount of 2-10% and the mixture is stirred. Then the mixture is separated into an oil layer and soap layer by centrifugal separation, etc., and then the oil layer is collected.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method for removing cholesterol from fats and oils.

[Prior art 1] Excessive intake of cholesterol is one of the causes of adult diseases such as arteriosclerosis and myocardial infarction, so reducing intake of dietary cholesterol has become a serious concern. There is. In fact, even in nutritional guidance provided in hospitals, people with high blood cholesterol levels are restricted from eating animal fats and egg products that contain high cholesterol levels. However, on the other hand, animal foods are not only rich in sensual appeal, but are nutritionally valuable sources of nutrients, such as their excellent amino acid balance. In addition, although fish oil contains a lot of cholesterol, it is also rich in polyunsaturated fatty acids such as eicosapencitric acid, which has a cholesterol-lowering effect, so if the cholesterol content can be reduced, further expansion of its uses can be expected. . For this reason, many studies have been conducted with the aim of removing cholesterol from animal fats and oils. For example, it is known that cholesterol contained in lard, head, fish oil, etc. can be removed to some extent during the deacidification or deodorization process in the aerosol refining process. Other methods include a method in which cholesterol is adsorbed and removed using adsorbents such as activated carbon, diatomaceous earth, and white clay (Japanese Unexamined Patent Application Publication No. 61-136598), and a method in which cholesterol contained in fats and oils is decomposed by microorganisms of the genus Rhodococcus (Japanese Patent Application Laid-open No. 61-136598). Kaihei 1-229097), etc. are known.

As mentioned above, cholesterol contained in fats and oils can be removed to some extent through the deacidification step in the general fats and oils refining process.

Hereinafter, for reference, an outline of a general deoxidizing process will be explained.

First, measure the acid value and phospholipid content of crude oil to determine the required amount of alkali. Next, 0.1 to 0.2% based on fats and oils
(by weight) of 75% phosphoric acid is added to create a state in which gummy substances such as phospholipids tend to aggregate and settle. Next, add sodium hydroxide equivalent to 110-120% of the acid value equivalent including phosphoric acid, mix with a line mixer to convert free fatty acids into soap layer cake, and separate the oil layer and soap layer with a centrifuge. To separate. The oil layer is separated and sequentially washed with a sodium hydroxide solution and hot water to remove trace amounts of remaining gum and pigment components. The oil after being washed with water is sent to a vacuum dryer and heated under reduced pressure to remove moisture and complete the deoxidation process. During this step, unsaponifiables such as cholesterol are removed along with the soap scum. For example, according to a report by the Japan Food Oil and Fat Inspection Association, approximately 5.0 mg/g of cholesterol contained in unrefined fish oil is reduced to 4.2 m
It has been reported that the amount decreases to about 7g ("Edible Processed Oils and Fats Technology Study Group Bulletin No. 5", page 23 Table 1. All Japan Margarine Association/Edible Processed Oils and Fats Technology Study Group, 1939)
(Published September 26, 2008).

[Problem to be Solved by the Invention 1] However, the original purpose of the deacidification step is to remove free fatty acids, and its effectiveness in terms of removing cholesterol is low, and even in the case of the above-mentioned fish oil, it still
0% cholesterol remains. Furthermore, the methods of adsorbing and removing cholesterol with an adsorbent and decomposing cholesterol with microorganisms have problems in terms of cost and safety, and are difficult to implement on a factory scale.

[Means for Solving the Problems 1] Therefore, in order to solve the above-mentioned problems, the present inventors removed cholesterol from fats and oils efficiently, inexpensively, safely, and using conventional equipment. As a result of research into a method for this purpose, it was discovered that cholesterol can be removed more effectively by adding a step of adding fatty acids to the normal deacidification step, leading to the present invention.

That is, the gist of the present invention is that after fatty acids are added to cholesterol-containing fats and oils, an alkaline aqueous solution is added, mixed and stirred, and then separated into an oil layer and a soap layer, and then the oil layer is fractionated. This is a method for producing low-cholesterol fats and oils.

Hereinafter, the content of the present invention will be explained in detail in the order of steps.

First, after adding fatty acids to fats and oils, an aqueous alkaline solution is added and mixed and stirred. The fats and oils targeted by the present invention are fats and oils containing cholesterol, and animal fats and oils such as fish oil, pork oil, and beef oil are suitable, for example. In addition, from the viewpoint of safety, the fatty acids to be added are desirably constituents of fats and oils, such as palmitic acid and
Fatty acids such as stearic acid, oleic acid, and linoleic acid are suitable. The amount of fatty acid added is preferably 5% or more, preferably 1 to 5% based on the fat and oil. The concentration and amount of the alkaline aqueous solution is preferably equivalent to 110% or more of the oxidation equivalent including the fatty acid to be added, and in the case of sodium hydroxide, the concentration is 10 to 30°Be, and the amount is 2 to 1O % (weight) is desirable.

Stirring is sufficient as long as the fats and oils, added fatty acids, and alkaline aqueous solution are sufficiently mixed, and the temperature during stirring is not necessarily higher than the high temperature (70 to 90℃
℃), any temperature that can keep the oil in a liquid state is sufficient.

Next, the mixture obtained in the stirring step is separated into an oil layer and a soap layer, and the oil layer is separated. The separation method is
Usually, a centrifugal separation method is used, and the continuous centrifuge currently used in many oil refineries for the deacidification process can be used as is. Even when using a batch type centrifuge, centrifugation at 100OG for about 5 minutes is sufficient. In addition, if fatty acids remain in the separated fats and oils,
If necessary, add an alkaline aqueous solution or hot water, stir, and separate the oil layer by centrifugation again. Through the above steps, low cholesterol fats and oils can be produced.

F Experiment example F The present invention will be explained below based on experimental examples.

Experimental Example 1> Refined fish oil (cholesterol content 2.3 mg/g) 40
1.6 g of each of valmitic acid, stearic acid, oleic acid, and linoleic acid were added to g, and 2 ml of 20% sodium hydroxide solution (approximately 26°Be) was added while stirring at 11,000 rpm with a homogenizer. Then 2
At 5℃ (80℃ for palmitic acid to make it liquid)
After stirring for 30 minutes, the resulting mixture was heated at 3000 rpm.
The mixture was centrifuged for 5 minutes and the oil layer was separated. The cholesterol content of the fractionated fish oil was measured. The results are shown in Table 1.

(Margins below) Table 1 From the results of this experiment, when the same treatment was performed without adding fatty acids (sample: control), cholesterol was not removed;
By adding fatty acids (invention sample No. 1.
2.3.4), it is clear that cholesterol is effectively removed.

<Experimental Example 2> 40 g each of purified fish oil (cholesterol content 2-1 mg/g), purified beef tallow (cholesterol content 0.8 mg/g), and purified pork fat (cholesterol content 0.3 mg/g)
After adding 1.6 g of oleic acid and adding an alkaline aqueous solution in the same manner as in Experimental Example 1, the mixture was mixed and stirred at 80'C11000 rpm for 20 minutes, and then centrifuged to separate the oil layer. The cholesterol content of each fractionated fat and oil was measured.

The results are shown in Table 2.

Table 2 From the results of this experiment, it was found that, according to the present invention, the addition of fatty acids can effectively
It is clear that cholesterol is removed.

<Experimental Example 3> Refined fish oil (cholesterol content 2.6 mg/g) 20
Oleic acid 0.5g, Ig, 2g, 4g to 0g
, 6g, 8g, lOg.

15 g was added, and while stirring with a homogenizer, an appropriate amount of alkaline aqueous solution was added depending on the amount of oleic acid added. i.e. 20% for 0.5-Ig of oleic acid
5ml of sodium hydroxide solution. 2g-1og oleic acid
20% sodium hydroxide solution 10+ ol for oleic acid, 20% sodium hydroxide solution 20+ for oleic acid 15g
ml was added. Then, 25°C.

After stirring at 11,000 rpm for 20 minutes, centrifugation was performed.
The oil layer was separated. The cholesterol content of each fractionated fat and oil was measured. The results are shown in Table 3.

(Left below) Based on the results of this experiment, it seems appropriate to add oleic acid at 0.5% or more, preferably 1 to 5%, based on fats and oils, considering cholesterol removal efficiency and economic efficiency. .

<Experimental Example 4> Refined fish oil (cholesterol content 2.3+ng/g) 4
1.6 g of oleic acid was added to 0 g, an aqueous alkali solution was added in the same manner as in Example 1, and the lo
After stirring at oorpm for 20 minutes, centrifugation was performed to separate the oil layer. The cholesterol content of each fractionated fat and oil was measured. The results are shown in Table 4.

From the results of this experiment, it was found that the mixing temperature of fats and oils, fatty acids, and aqueous alkaline solutions was not as high as in the conventional deoxidation process (
It is clear that the cholesterol removal efficiency is improved even at low temperatures.

[Example] Refined fish oil (cholesterol content 2.3 mg/g) 40
Add 1.6 g of oleic acid to
After stirring for 0 minutes, centrifugation was performed to separate the oil layer. The obtained fats and oils are washed again with an alkaline aqueous solution and boiling water,
It was dried in a vacuum dryer at 60° C. for 30 minutes to remove water and obtain low cholesterol fish oil. Cholesterol content and AV of the purified fish oil before this treatment and the low-cholesterol fish oil obtained according to the present invention.

The fatty acid composition and water content were measured and the results are shown in Table 5.

From this result, cholesterol is 2゜3 m before treatment.
g/g to 0.6 mg/g (about a quarter),
There was no significant difference in AV, fatty acid composition, and water content from the purified fish oil before treatment. In addition, the low-cholesterol fish oil according to the present invention had a flavor that was almost the same as that of the purified fish oil before treatment, and was good in sensory terms.

(Margins below) Table 5 [Effects] As described above, according to the present invention, cholesterol contained in fats and oils can be removed efficiently and at low cost without impairing the quality of the fats and oils.

Claims (1)

[Claims] A method for producing low-cholesterol fats and oils, which comprises adding fatty acids to cholesterol-containing fats and oils, adding an alkaline aqueous solution, mixing and stirring, separating the mixture into an oil layer and a soap layer, and then fractionating the oil layer.