JPH06340889A - Production of oryzanol-rich rice bran oil - Google Patents

Abstract

PURPOSE:To provide a purification method by which rice bran oil or rice embryo oil is purified efficiently in a high yield and oryzanols., which are physiolgically useful and removed by the conventional purification method, are concentrated to give an edible oil rich in nutriment. CONSTITUTION:A rice bran oil is purified by removing fatty acids contained in it by steam distillation in a vacuum without using an alkali such as potassium hydroxide, giving the oil contg. high concns. of oryzanols. The fatty acids contained are removed by steam distillation by blowing steam into the oil in a high vacuum at a high temp. pref. by using a single-shell vacuum distillation apparatus convenient for evaporation and separation.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing vegetable oil, and more particularly to a method for treating rice bran oil having a large amount of free fatty acids.

[0002]

2. Description of the Related Art Usually, vegetable oils used as edible oils include rice bran oil, soybean oil, rapeseed oil, corn oil, safflower oil, palm liquid oil, etc. Is a free fatty acid contained in crude oil,
Gums, waxes, sterins, hydrocarbons, pigments, and
A small amount of metal soap was removed in the refining process to obtain a product. This purification process includes degumming, dewaxing, deoxidizing,
Degumming oil obtained by decolorizing, low-temperature dewaxing and deodorizing steps, adding water and acid to crude oil, hydrating, expanding and solidifying the gum, and then removing with a centrifuge. The remaining 0.2 to 0.3% gum is removed by alkali deoxidation at the same time as the alkali soap of free fatty acids, and further the pigment, soap component, heavy metals that could not be removed by alkali purification, and other trace components Waxes and glycerides of saturated fatty acids, which cause crystallization and turbidity at low temperature after removal with an adsorbent such as activated clay, are winterizations, and free fatty acids, odorous aldehydes, ketones, etc. generated in the decolorization process Is removed in the deodorizing process to obtain a product.

Crude rice bran oil contains 5-15% free fatty acids, 2-3% wax content, 1-3% gum quality,
Furthermore, it contains around 2% oryzanols that are not contained in other vegetable oils, the refining process is complicated and difficult, the refining yield is extremely poor compared to other vegetable oils, and when free fatty acids are removed by alkali, oryzanols are alkaline salts. Was being removed at the same time.

In addition to such a chemical method which is a conventional method for removing free fatty acids by alkalis, a physical refining method (PR method) is known as a method for removing free fatty acids under high temperature and high vacuum.
As a method for removing free fatty acids from palm liquid oil, thin film deoxidation using fillers is performed overseas under high temperature and high vacuum. In addition, P. As the R method, refining of rice bran oil that has been made to flow in a thin film on the heating surface under high temperature and high vacuum is known in Japan.

These P. The R method deteriorates the quality of oil due to high temperatures, etc., further deteriorates the quality of oil due to the tendency of oil to adhere to the heating surface, lowers the yield, and requires maintenance work for the equipment. There was a problem.

[0006]

DISCLOSURE OF INVENTION Problems to be Solved by the Invention In view of these drawbacks in the process of refining rice bran oil, the present invention has led to the completion of the present invention, and as a result, the present invention has been completed. Well, while refining rice oil and rice germ oil with improved yields, at the same time enriching oryzanols with physiologically useful effects that were removed by conventional refining methods, refining edible oil rich in nutrients There is a way to provide.

[0007]

The object of the present invention is to purify rice bran crude oil by removing the fatty acids contained by steam distillation under vacuum without using alkalis such as caustic soda to remove oryzanols. By using a vacuum distillation apparatus with a single shell structure, which is convenient for concentrated rice oil production and evaporation separation, steam is blown into the oil under high vacuum and high temperature, and the fatty acid contained is steam distilled. This can be achieved by the method for producing rice oil described above.

A feature of the present invention is that steam distillation is carried out to remove fatty acids contained in rice bran crude oil and to concentrate oryzanols. In the present invention, oryzanol refers to a ferulic acid ester, and is a sterene or terpene alcohol as an alcohol portion for ester formation.

The composition of the rice bran crude oil used in the present invention is not particularly specified, but it contains fatty acids and preferably contains at least 1% by weight of oryzanols. Therefore, in the present invention, rice bran crude oil is a concept including conventionally known rice germ crude oil and the like.
In the present invention, the steam distillation treatment step of rice bran crude oil,
Conventionally, it may be replaced with a deoxidizing and deodorizing treatment step which has been subjected to an alkali treatment, but basically, it may be used for any of various steps in the rice bran crude oil refining step,
It may be performed once or a plurality of times (continuous or discrete). Therefore, the steam distillation treatment step may be the final step of the purification step or an intermediate step.

That is, the refining process of rice bran crude oil according to the present invention can be variously selected according to a desired rice bran oil composition, and specifically, the following flow can be exemplified. Rice bran crude oil → degumming process → dewaxing process → decolorization process → steam distillation treatment process of the present invention (deoxidation, etc.) → decolorization process → low temperature dewaxing process → steam distillation treatment process of the present invention (deodorization, etc.) rice bran crude oil → dewaxing Gum process → dewaxing process → decolorization process → steam distillation treatment process of the present invention (deoxidation, deodorization, etc.) As described above, in the present invention, the rice bran crude oil to be steam distilled is a degumming process, a dewaxing process, Those prepared through a bleaching step are particularly preferable. The degumming process, for example,
This is a step of adding phosphoric acid and water to rice bran crude oil and centrifuging to obtain rice bran crude oil (degummed crude oil) having a phosphorus content of 0.01% by weight or less. The dewaxing step is a step of removing the wax component from the degummed crude oil, and the decolorizing step is a step of adsorbing and removing the pigment component with activated clay.

In the present invention, the vacuum distillation apparatus for steam-distilling rice bran crude oil has a single shell structure. Here, the single shell structure refers to a continuous space structure in which the distillation processing section can be regarded as one container, and various conventionally known structures can be used in the present invention, but preferably a multi-stage structure is used. It is a thing. The constituent material of the device is not particularly limited, but stainless steel (for example, SUS316 or the like) is exemplified from the viewpoint of corrosion resistance, durability and the like.

The distillation conditions of the vacuum distillation apparatus are as follows:
4 mmHg, a temperature of around 220 ° C., and a steam blowing amount of 2 to 4 wt% of the amount of rice bran crude oil is preferable. In the present invention, by steam-distilling rice bran crude oil with this vacuum distillation apparatus, most of the free fatty acids contained in the oil are evaporated, and concentrated rice oil of oryzanols having a low acid value is obtained.

An example of the vacuum distillation deodorizing apparatus used in the present invention is shown in FIG. The entire deodorization tower (TW-1) 1 is maintained at 6 Torr or less by the vacuum generator (VP) 2, and the upper three tanks, that is, the preheating tank 3, the heating tank 4, and the deoxidizing tank 5 are used. Deoxidizing section 6 mainly for removing free fatty acids, and four lower tanks, namely, deodorizing tanks 7 and 8,
9 and a precooling tank 10, and a deodorizing section 11 for removing the remaining free fatty acids and odorous substances.

[0014]

EXAMPLES Specific examples of the present invention will be described below, but the present invention is not limited thereto. Example 1 An acid value of 25, a gum quality of 2.5%, a wax content of 3%, an oryzanol content of 1.8%, and a black-hued rice bran crude oil were degummed, dewaxed, and decolorized to a temperature of 220 ° C. , A vacuum degree of 3 mmHg, a steam injection amount of 4 wt%, steam distillation was performed with the vacuum distillation apparatus of the single shell structure shown in FIG. 1, an acid value of 1.2 (alkali blue acid value), and a deoxidized oil of reddish brown hue. Got

After decolorization and low-temperature dewaxing of this deoxidized oil, deodorization was performed with a deodorizing device at a vacuum degree of 4 mmHg, a temperature of 250 ° C., and a steam blowing amount of 3% to obtain an edible oil. The features were as follows. Acid value 0.05 (Alkali blue acid value) Oryzanols 2.0% (Ultraviolet 315mμ) Color (Robibond 133.4mm cell) R-5.0
Y-50 Properties Transparent appearance, good flavor Example 2 Acid value 15, gum content 1.3%, wax content 1.5%, oryzanols content 1.2%, and rice bran crude oil of black-green hue (rice germ crude oil) ) Is degummed, dewaxed and decolorized,
Temperature 218 ° C, vacuum degree 3 mmHg, steam injection amount 3
Steam distillation was performed with a single shell vacuum distillation apparatus shown in FIG. 1 at wt% to obtain a deoxidized oil having an acid value of 1.1 (alkali blue acid value) and a reddish brown hue.

After decolorization and low-temperature dewaxing of the deoxidized oil, deodorization was performed with a deodorizing device at a vacuum degree of 4 mmHg, a temperature of 240 ° C., and a steam blowing amount of 3% to obtain edible germ oil. The features were as follows. Acid value 0.06 (Alkali blue acid value) Oryzanols 1.4% (Ultraviolet 315 mμ) Color (Robibond 133.4 mm cell) R-6.0
Y-60 Properties Transparent appearance, good flavor Example 3 Degumming and dewaxing rice bran crude oil having an acid value of 25, gum quality 2.5%, wax content 3%, oryzanols content 1.8%, and black-green hue. Decolorization operation was carried out, steam distillation was carried out at a temperature of 220 ° C., a vacuum degree of 3 mmHg, and a steam injection amount of 4 wt% in the single-shell vacuum distillation apparatus (deoxidation section) shown in FIG. Alkali blue acid value),
And a reddish brown deoxidized oil is obtained, and the deoxidized oil is vacuumed in the vacuum distillation apparatus (deodorizing section) at a vacuum degree of 4 mmHg and a temperature of 250
Deodorization was carried out at a temperature of 3 ° C. and a steam flow rate of 3% to obtain edible rice oil.

The characteristics are as follows. Acid value 0.06 (Alkali blue acid value) Oryzanols 2.0% (Ultraviolet 315mμ) Color (Robibond 133.4mm cell) R-7.0
Y-70 Property Good flavor

[0018]

INDUSTRIAL APPLICABILITY In refining rice bran crude oil, the present invention eliminates free fatty acids and the like by steam distillation without using alkali, which has been conventionally used as a chemical method, in the refining step. It is possible to provide an edible oil that is rich in oryzanols and is useful for maintaining good health without sacrificing health.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing a structural example of a vacuum distillation apparatus used in the present invention.

[Explanation of symbols]

 1 Deodorization tower (TW-1) 2 Vacuum generator (VP) 3 Preheating tank 4 Heating tank 5 Deoxidation tank 6 Deoxidation part 7 Deodorization tank 8 Deodorization tank 9 Deodorization tank 10 Pre-cooling tank 11 Deodorization part 12 Raw material ( Rice bran crude oil 13 Raw material supply pump (P-1) 14 Integrated flow meter (FSBC) 15 Cooling tank (V-1) 16 Blow steam (SS) 17 Heat pipe 18 Fatty acid condenser (H-1) 19 Cooling Water (C.W.) 20 Fatty acid receiving tank (V-3) 21 Drop tank (V-2) 22 Oriza oil discharge pump (P-2) 23 Steam for heating (HS)

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Nori Arai 14-11 Minato Ichikawa, Chiba Prefecture

Claims (2)

[Claims] 1. A method for producing rice bran oil in which, when refining rice bran crude oil, the fatty acids contained are removed by steam distillation under vacuum without using alkalis such as caustic soda, and oryzanols are concentrated. 2. A vacuum distillation apparatus having a single shell structure, which is convenient for evaporation and separation, is used to blow steam into oil under high vacuum and high temperature to steam-distill the contained fatty acid. Manufacturing method of rice oil.