JP7699892B2 - Method for producing cooking oil composition, and cooking oil composition - Google Patents

Description

The present invention relates to a method for producing an oil and fat composition for cooking with heat, and to an oil and fat composition for cooking with heat.

In recent years, consumers have become increasingly concerned about food quality. This concern also extends to edible oils and fats used in the production of processed foods (fried foods, etc.).

It is known that fats and oils deteriorate when exposed to heat, light, etc. When fats and oils are exposed to heat or light, hydrolysis occurs if moisture is present, and oxidation occurs if oxygen is present. As a result of deterioration, the acid value of the fats and oils increases, and the flavor and color tone deteriorate. In particular, in the production of fried foods (fries, tempura, deep-fried chicken, etc.), cooking is performed using fats and oils heated to around 180°C, so it is necessary to suppress deterioration due to heating for the fats and oils used in fried foods (hereinafter also referred to as "frying fats and oils").

For example, the "Standards for Foods, Additives, etc. (Ministry of Health and Welfare Notification No. 370 of 1959)" stipulates that for instant noodles (equivalent to fries), the oil contained in the noodles must not have an acid value exceeding 3, or a peroxide value exceeding 30.

In addition, deterioration of frying oils and fats due to heat or other factors can cause the color of the frying oil to darken. If the color of the frying oil and fat becomes dark, the fried food produced using the oil and fat will also become discolored, impairing the appearance.

For example, Patent Document 1 discloses cooking oils and fats containing 0.1 to 1 μmol/g of sodium or potassium (2.2 to 22.98 mg/kg as sodium) and shows the effect of suppressing the increase in acid value due to heating, while Patent Document 2 discloses frying oils and fats containing 0.5 to 2.0 mg/kg of sodium or potassium in which the increase in acid value during frying is suppressed, and shows examples in Comparative Example 1 (Na content 3.7 mg/kg) and Comparative Example 2 (5.8 mg/kg) that are inferior in the effect of suppressing the increase in acid value and in heat discoloration.

Patent No. 4798310 JP 2013-252129 A

Thus, although cooking oils and fats containing alkali metals are expected to suppress the increase in acid value and the coloring during cooking, the effects are not necessarily high. Furthermore, the higher the effect of the cooking oil and fat composition in suppressing the increase in acid value and the coloring during cooking, the longer cooking can be done with the cooking oil and fat composition, so there is a demand for further improvement in these effects.

The present invention was made in consideration of the above circumstances, and aims to provide a technology that can suppress the increase in acid value and/or the suppression of coloring of a cooking oil/fat composition during cooking.

The present inventors discovered that the above problems can be solved by adding an alkali metal and an emulsifier, and/or an emulsifier containing an alkali metal, to refined oils and fats so that the refined oils and fats having an acid value of 0.03 or less are present in the cooking oil composition at 93 mass% or more, and the alkali metal is present in the cooking oil composition at 0.02 to 5 mass ppm, and thus completed the present invention. Specifically, the present invention provides the following.

(1) The method includes adding an alkali metal and an emulsifier, and/or an emulsifier containing an alkali metal, to a refined oil or fat so that the refined oil or fat having an acid value of 0.03 or less is present in the cooking oil or fat composition at 93% by mass or more, and the alkali metal is present in the cooking oil or fat composition at 0.02 to 5.0 ppm by mass.
A method for producing a cooking oil and fat composition.
(2) The method for producing a cooking fat and oil composition according to (1), wherein the emulsifier is at least one selected from the group consisting of polyglycerol fatty acid esters, sucrose fatty acid esters, sorbitan fatty acid esters, polyoxyethylene sorbitan monooleate, organic acid monoglycerides, and mono fatty acid glycerides.
(3) The method for producing a fat or oil composition for cooking according to (1) or (2), wherein the emulsifier is contained in the fat or oil composition for cooking in an amount of 0.02 to 5.00% by mass.
(4) The method for producing an oil or fat composition for cooking according to any one of (1) to (3), wherein the emulsifier is one or more selected from polyglycerol fatty acid esters having an HLB value of 3.5 or less, sucrose fatty acid esters having an HLB value of 3 or less, glycerol monooleate succinate, glycerol monooleate citrate, polyoxyethylene sorbitan monooleate, and mono fatty acid glycerides in which 47% by mass or more of the fatty acids constituting the mono fatty acid glyceride are polyunsaturated fatty acids.
(5) The cooking oil composition according to any one of (1) to (4), wherein the refined oil contains one or more selected from the following adsorption-treated oil, deodorized oil A, deodorized oil B, and deodorized oil C.
Adsorption-treated oils and fats: Adsorption-treated oils and fats that have been subjected to an adsorption process in which the oils and fats that have been subjected to a deodorization process are brought into contact with a silica-magnesia-based preparation in a liquid state and at less than 80 ° C. Deodorized oils and fats A: Re-deodorized palm-based deodorized oils and fats that have been subjected to a deodorization process so that the gamma-tocotrienol content in the deodorized oils and fats is 250 mass ppm or less and the acid value is 0.03 or less Deodorized oils and fats B: Deodorized oils and fats that are one or more selected from soybean oil, corn oil, cottonseed oil, and sunflower oil, that have been subjected to a deodorization process so that the total tocopherol content in the deodorized oils and fats is 900 mass ppm or less and the acid value is 0.03 or less Deodorized oils and fats C: Rapeseed deodorized oils and fats that have been subjected to a deodorization process so that the total tocopherol content in the deodorized oils and fats is 550 mass ppm or less and the acid value is 0.03 or less (6) The method for producing a cooking oil and fat composition according to (5), wherein the refined oil and fat has an acid value of 0.00 to 0.01.
(7) The method for producing a cooking oil/fat composition according to any one of (1) to (6), wherein the refined oil/fat is a refined oil/fat that has been subjected to a step of contacting the oil/fat with ozone prior to the deodorizing step.
(8) The method for producing a cooking fat or oil composition according to any one of (1) to (7), further comprising adding silicone oil to the cooking fat or oil composition so that the silicone oil is present in an amount of 0.5 to 10 ppm by mass.
(9) A cooking oil/fat composition, comprising 0.02 to 5 ppm by mass of alkali metal and 93% by mass or more of refined oil/fat having an acid value of 0.03 or less.
(10) The cooking oil/fat composition according to (9), further comprising 0.5 to 10 ppm by mass of silicone oil in the cooking oil/fat composition.
(11) The cooking fat and oil composition according to (9) or (10), which is produced by any one of the production methods according to (1) to (7).
(12) The cooking fat or oil composition according to any one of (9) to (11), characterized in that the cooking fat or oil composition inhibits an increase in acid value and/or inhibits coloring after cooking.

The present invention provides a technology that can suppress an increase in acid value and/or coloring of a cooking oil/fat composition during cooking. Furthermore, flavor stability is improved by going through a process of contacting the oil/fat with ozone.

The following describes in detail the embodiments of the present invention. Note that the present invention is not limited to the following embodiments. In this specification, "A (number) to B (number)" means "A or more and B or less," and the ratio means the mass ratio.

In the present invention, the acid value is a value measured in accordance with "Standard Test Method for Analysis of Fats, Oils and Fat 2.3.1-2013 Acid Value" established by the Japan Oil Chemists' Society. The acid value indicates the amount of free fatty acid contained in the oil and fat, and is expressed as the number of milligrams of potassium hydroxide required to neutralize 1 g of sample oil. The content of alkali metals can be quantified by atomic absorption spectrometry. The content of each fatty acid (e.g., oleic acid) in the fatty acids constituting the emulsifier can be measured in accordance with "Standard Test Method for Analysis of Fats, Oils and Fat 2.4.2.3-2013 Fatty Acid Composition (Capillary Gas Chromatography)" established by the Japan Oil Chemists' Society. The gamma-tocotrienol content and tocopherol content contained in the oil and fat composition can be measured in accordance with "Standard Test Method for Analysis of Fats, Oils and Fat 2.4.10-2013 Tocopherol (Fluorescence Detector-High Performance Liquid Chromatography)" established by the Japan Oil Chemists' Society. The iodine value can be measured in accordance with the "Standard Methods for the Analysis of Fats, Oils and Related Materials 2.3.4.1-2013 Iodine Value (Wiess-Cyclohexane Method)" established by the Japan Oil Chemists' Society. The color tone was calculated by measuring the yellow chromaticity (Y value) and red chromaticity (R value) of the test oil using the Lovibond colorimetric method (0.5 inch cell) and calculating "Y + 10R".

<Method of producing cooking oil and fat composition>
The production method of the present invention includes a step of adding an alkali metal and an emulsifier, and/or an emulsifier containing an alkali metal, to a refined oil or fat so that the refined oil or fat having an acid value of 0.03 or less is present in the cooking oil or fat composition at 93 mass% or more and the alkali metal is present in the cooking oil or fat composition at 0.02 to 5 mass ppm. In addition, the method may further include a step of contacting the oil or fat with ozone and/or a step of adding a silicone oil.

Details of refined fats and oils, alkali metals, and emulsifiers will be described later. It is difficult to disperse or dissolve an alkali alone in fats and oils, so it is preferable to add the alkali metal to the fats and oils in the presence of an emulsifier. For example, an emulsifier and an alkali metal can be added to the fats and oils at the same time, or an emulsifier containing an alkali metal can be added to the fats and oils. It is preferable to gradually dilute the alkali metal and the emulsifier. For example, a method can be used in which the alkali metal and the emulsifier are diluted with a part of the fats and oils, and the dilution is added to the remaining fats and oils. The fats and oils to be diluted are the fats and oils to be blended in the fats and oils composition for cooking. The temperature of addition is preferably a temperature at which the emulsifier becomes liquid, and is preferably 0 to 70°C. When heating, there is no problem with heating only the emulsifier or the dilution.
When the alkali metal and the emulsifier are added, it is preferable to add the silicone oil at the same time.

[Oils and fats]
The cooking oil and fat composition contains oil and fat. As the oil and fat, edible oil and fat can be used. For example, animal and vegetable oils and fats, oils and fats synthesized from glycerin and fatty acids, and fractionated oils thereof, transesterified oils, hydrogenated oils, etc. can be mentioned. In addition, a single oil and fat or a blend of multiple oils and fats can be mentioned.
Examples of animal and vegetable oils and fats include soybean oil, rapeseed oil, high oleic rapeseed oil, sunflower oil, high oleic sunflower oil, olive oil, safflower oil, high oleic safflower oil, corn oil, cottonseed oil, rice oil, sesame oil, perilla oil, linseed oil, peanut oil, grapeseed oil, beef tallow, milk fat, fish oil, coconut oil, palm oil, and palm kernel oil.
Examples of fats and oils synthesized from glycerin and fatty acids include medium-chain triglycerides (MCTs).
Examples of fractionated oils include fractionated palm oils such as palm olein, palm superolein, palm stearin, and palm midfraction.
As the interesterified oil, an interesterified oil of palm oil or a fractionated palm oil with other liquid fats and oils, or an interesterified oil of MCT with vegetable oil or the like can be used.
Examples of the hydrogenated oil include hydrogenated oils of animal and vegetable oils, fractionated oils of animal and vegetable oils, and hydrogenated oils of interesterified oils.

[Refined fats and oils]
In the present invention, refined oils and fats are oils and fats that have been subjected to at least a deodorizing step.
The fats and oils contained in the cooking oil composition are refined fats and oils only, or fats and oils containing refined fats and oils. The cooking oil composition contains 93% by mass or more of refined fats and oils having an acid value of 0.03 or less. When the cooking oil composition contains 93% by mass or more of refined fats and oils having an acid value of 0.03 or less, the cooking oil composition can have sufficient functions as a cooking oil composition used for heating purposes. The refined fats and oils having an acid value of 0.03 or less contained in the cooking oil composition are preferably 97% by mass or more and 99.98% by mass or less. The refined fats and oils having an acid value of 0.03 or less contained in the cooking oil composition are more preferably 99% by mass or more and 99.97% by mass or less. The cooking oil composition can contain refined fats and oils having an acid value of more than 0.03, or unrefined oils, but it is particularly preferable that all the fats and oils contained in the cooking oil composition are refined fats and oils having an acid value of 0.03 or less.

Fats and oils are naturally derived, and at present, no components other than free fatty acids that increase the acid value, or any coloring substances or substances that promote coloring have been identified.

Furthermore, it is preferable that the refined oil contains one or more selected from the following adsorption-treated oil, deodorized oil A, deodorized oil B, and deodorized oil C.

(Oils and fats treated with adsorption)
The adsorption-treated oils and fats are produced by an adsorption process in which oils and fats that have been subjected to a deodorizing process are contacted with a silica-magnesia-based preparation in a liquid state at less than 80° C. By contacting, it is possible to remove not only free fatty acids in the oil and fats, but also components that increase the acid value during frying (accelerating substances), coloring substances, or substances that promote coloring.

The oils and fats to be subjected to the deodorization process before the adsorption process can be unrefined oils and fats, or semi-refined oils and fats that have been subjected to a process selected from a degumming process, a deoxidizing process, a bleaching process, a dewaxing process, etc., or refined oils and fats (deodorized oils and fats) that have been subjected to a process selected from a degumming process, a deoxidizing process, a bleaching process, a dewaxing process, etc., and a deodorization process. In addition, refined oils and fats that have been subjected to a process selected from a degumming process, a deoxidizing process, a bleaching process, a dewaxing process, etc. can also be used. Note that one of the objectives of the present invention is to provide oils and fats with a sufficiently low acid value, but the acid value can be reduced in the deodorization process and adsorption process described below, so the deoxidization process is not necessarily required. When the deoxidization process is performed, the load on the deodorization process can be reduced. In addition, in the case of oils and fats that are significantly colored, it is preferable to use oils and fats that have been subjected to a bleaching process.

There is no problem if the conditions for the deodorization process before the adsorption process are within the range of deodorization conditions normally used in refining oils and fats, but it is preferable that the acid value of the oils and fats that have undergone the deodorization process (deodorized oils and fats) is 0.2 or less. The lower the acid value, the greater the effect of the adsorption process, and the more sufficiently the acid value of the refined oils and fats can be reduced. It is more preferable that the acid value of the oils and fats that have undergone the deodorization process is 0.1 or less.

The conditions for the deodorization process are not particularly limited, but for example, the deodorization temperature is preferably 180 to 280°C, the degree of vacuum is 100 to 800 Pa, the amount of water vapor is 0.3 to 10 mass% (relative to oil and fat), and the deodorization time is preferably 30 to 120 minutes. The deodorization temperature is more preferably 200 to 270°C, even more preferably 230 to 260°C, and most preferably 240 to 250°C. The degree of vacuum is more preferably 200 to 600 Pa, and even more preferably 300 to 500 Pa. The amount of water vapor is more preferably 1 to 8 mass% (relative to oil), even more preferably 1 to 5 mass% (relative to oil), and most preferably 1 to 3 mass% (relative to oil). The deodorization time is more preferably 40 to 120 minutes, and even more preferably 40 to 80 minutes.

In the deodorization step, citric acid may be added at the end of the deodorization process. Adding citric acid increases oxidation stability. Citric acid is preferably added at 10 to 50 ppm, and more preferably at 26 to 50 ppm, to the deodorized oil. Citric acid does not disperse or dissolve in oil as is, so it is preferably added as a 5 to 20% by mass aqueous solution.

The adsorption-treated oils and fats have an adsorption process after the deodorization process, but another process can also be performed between the deodorization process and the adsorption process. It is preferable that the process following the deodorization process is the adsorption process. Since the adsorption process is performed at less than 80°C, the adsorption process may be performed after cooling, storage, etc., as necessary. The silica-magnesia-based preparation used in the adsorption process is a preparation of silica (silicon dioxide) and magnesia (magnesium oxide), in which silica particles and magnesia particles are dispersed and mixed. For example, a mass ratio of silica:magnesia of 1:5 to 3:1 is preferable. In addition, a preparation consisting of a combination of silicon dioxide, magnesium oxide, and water can be used as the silica-magnesia-based preparation, and for example, a composition of 30 to 80 mass% silicon dioxide, 10 to 50 mass% magnesium oxide, and 5 to 20 mass% water is preferable. These silica-magnesia-based preparations can be obtained, for example, by dispersing silica and magnesia particles in water as nano-order unit particles that do not dissolve, mixing them uniformly, and combining them to form a tightly integrated compound without forming chemical bonds that involve the exchange or recombination of atoms between the particles. Commercially available products (Mizuka Life, manufactured by Mizusawa Industrial Chemicals Co., Ltd.) can also be used.

When fats and oils are in a liquid state, sufficient contact efficiency with the silica-magnesia preparation can be achieved. Furthermore, if the contact temperature is 80°C or higher, the silica-magnesia preparation will cause the trace components of the fats and oils to change in quality, resulting in the generation of unpleasant odors, making a deodorization process (steam distillation) essential. However, if the deodorization process is carried out after the adsorption process, slight hydrolysis will occur, making it difficult to obtain refined fats and oils with a low acid value. For this reason, the contact temperature is preferably in the range of -10 to 79°C, -5 to 75°C, 0 to 60°C, 5 to 60°C, or 5 to 50°C, with 5 to 40°C being more preferable, and 10 to 30°C being most preferable.

Contact between the oil and the silica-magnesia preparation can be achieved by adding the silica-magnesia preparation to the oil and then stirring and filtering or centrifuging. A simple and preferred method is to pass the liquid oil through a container filled with the silica-magnesia preparation. For example, the silica-magnesia preparation can be filled into a filter (single-plate filter, filter press, leaf filter, etc.), column, etc., and the oil can be passed through to bring them into contact. In particular, it is more preferred to pass the oil through a cartridge-type filter filled with the silica-magnesia preparation.

Since the amount of impurities adsorbed by the silica-magnesia-based preparation, such as free fatty acids, in the oils and fats that have been deodorized is small, a short contact such as filtration, or the use of a very small amount of the silica-magnesia-based preparation is sufficient. Therefore, there are no particular limitations on the contact time between the oils and fats and the silica-magnesia-based preparation, or the amount of the silica-magnesia-based preparation used. The contact time between the oils and fats and the silica-magnesia-based preparation is preferably 0.5 minutes or more, more preferably 5 minutes or more, even more preferably 15 minutes or more, and most preferably 30 minutes to 3 hours. In addition, the amount of the silica-magnesia-based preparation used is preferably 0.05 parts by mass or more per 100 parts by mass of the oils and fats, more preferably 0.1 to 5 parts by mass per 100 parts by mass of the oils and fats, and even more preferably 0.5 to 3 parts by mass per 100 parts by mass of the oils and fats.

The purification process for the adsorption-treated oils and fats is completed with the above-mentioned adsorption process, but additional purification processes, fractionation processes, mixing processes (addition processes), etc. may be carried out as necessary. However, if a process of contacting the oils and fats with steam at 140°C or higher is carried out, as in the deodorization process, a small amount of hydrolysis of the oils and fats occurs, while the free fatty acids are removed by distillation, so that the equilibrium state of the amount of free fatty acids in the oils and fats is such that the acid value of the oils and fats exceeds 0.01, so it is preferable not to carry out this process.

The acid value of the adsorption-treated oils and fats is 0.00 to 0.03, and preferably 0.00 to 0.01. An acid value of 0.00 to 0.01 is a range that cannot be achieved by ordinary deoxidation and deodorization processes alone. The acid value of the adsorption-treated oils and fats is more preferably 0.001 to 0.008.

(Deodorized oil A)
The deodorized oil A is a re-deodorized palm-based deodorized oil that has been subjected to a deodorization process so that the γ-tocotrienol content in the deodorized oil is 250 mass ppm or less and the acid value is 0.03 or less. The palm-based deodorized oil is a deodorized oil that has been subjected to a physical refining process or a chemical refining process, and is preferably a palm-based deodorized oil (RBD palm-based oil) that has been subjected to a physical refining process. The palm-based deodorized oil is palm oil or a fractionated oil of palm oil. Examples of the fractionated oil of palm oil include palm olein, palm midfraction, and palm stearin. From the viewpoint of the workability of the oil composition of the present invention, it is preferable that the deodorized oil A is liquid at around 10 to 20° C., and in that case, it is preferable that the melting point of the deodorized oil A is low. Therefore, it is preferable to use palm oil and/or palm olein. More preferably, RBD palm oil and/or RBD palm olein is used. Palm olein is a fraction with a high iodine value obtained by fractionating palm oil once or multiple times, and palm olein with a particularly high iodine value is sometimes called palm superolein. As the iodine value becomes high, the fat becomes difficult to solidify, so palm olein preferably has an iodine value of 56 or more, more preferably an iodine value of 60 or more, and even more preferably an iodine value of 65 or more. The upper limit of the iodine value of palm olein is not particularly limited, but is preferably 72 or less, more preferably 70 or less.

The gamma-tocotrienol content in deodorized oil A is preferably 50 to 250 ppm by mass or less, more preferably 50 to 230 ppm by mass, even more preferably 50 to 200 ppm by mass, and most preferably 50 to 150 ppm by mass.

The acid value of the deodorized oil A is 0.00 to 0.03, preferably 0.01 to 0.03, more preferably 0.02 or less, and most preferably 0.01 to 0.02.

Deodorized oil A is obtained by using palm-based deodorized oil that has been deodorized once as a raw material and deodorizing it again. The palm-based deodorized oil can be one that has been chemically refined including an alkaline deoxidation step (NBD palm-based oil) or one that has been physically refined without an alkaline step (RBD palm-based oil). Since RBD palm-based oil is widely distributed, it is preferable to use RBD palm-based oil. In the present invention, this palm-based deodorized oil is re-refined including deodorization and used as deodorized oil A. The re-refining step can be only the deodorization step, but it is possible to perform chemical refining or physical refining. Since the acid value of the palm-based deodorized oil used as the raw material has been reduced in the initial refining, an alkaline deoxidation step for the purpose of reducing the acid value is not essential. From the viewpoint of flavor, physical refining that includes a bleaching step, a deodorizing step, or a water washing step, a bleaching step, and a deodorizing step is preferable. It is also preferable to use chemical refining, which involves deacidification, decolorization, and deodorization processes.

For processes other than deodorization, general conditions for refining oils and fats can be used.

The production of deodorized oil A involves a deodorization process so that the gamma-tocotrienol content and acid value in the deodorized oil meet the requirements, but these requirements can be achieved by carrying out the deodorization process under excessive conditions. The deodorization conditions are as follows: a reduced pressure steam distillation apparatus is used, but the deodorization can be carried out at a higher temperature, under a higher vacuum, with a higher amount of steam, or for a longer period of time than the usual conditions for reduced pressure steam distillation. For example, when the deodorization is carried out at a deodorization temperature of 200 to 280°C, a vacuum degree of 100 to 500 Pa, a steam amount of 1 to 8% by mass (relative to oil), and a deodorization time of 30 to 120 minutes, it is preferable to satisfy two or more conditions selected from a deodorization temperature of 235°C or higher, a vacuum degree of 500 Pa or lower, a steam amount of 2.0% by mass or higher (relative to oil), and a deodorization time of 50 minutes or longer, and more preferably to satisfy three conditions. The deodorization temperature is more preferably 245°C or higher, and even more preferably 250°C or higher. The degree of vacuum is preferably 400 Pa or less, more preferably 280 Pa or less, and even more preferably 260 Pa or less. The amount of water vapor is more preferably 2.4% by mass or more (relative to oil and fat), and even more preferably 3% by mass (relative to oil and fat). The deodorization time is more preferably 60 minutes or more, and even more preferably 70 minutes or more.

In the deodorizing step, the temperature is lowered at the end of the deodorizing process, and it is preferable to add citric acid at this time. Adding citric acid further increases oxidation stability. It is preferable to add 1 to 50 ppm of citric acid to the deodorized oil and fat, and more preferably 1 to 30 ppm. Since citric acid does not disperse or dissolve in oil as it is, it is preferable to add it as a 5 to 20 mass % aqueous solution.

(Deodorized oil and fat B)
The deodorized fat B is one or more selected from soybean oil, corn oil, cottonseed oil, and sunflower oil, which has been subjected to a deodorization process so that the total tocopherol content in the deodorized fat is 900 mass ppm or less and the acid value is 0.03 or less. Soybean oil and corn oil having a fatty acid composition similar to that of soybean oil are preferred. The iodine value of the fat is a value reflecting the constituent fatty acids of the fat, and is also an index of the ease of deterioration. The iodine value of the deodorized fat B is preferably 100 to 145, more preferably 120 to 140.

The total tocopherol content in deodorized oil B is preferably 100 to 850 ppm by mass, or 100 to 800 ppm by mass, more preferably 100 to 600 ppm by mass, even more preferably 150 to 550 ppm by mass, even more preferably 200 to 460 ppm by mass, and most preferably 200 to 400 ppm by mass. Furthermore, the γ-tocopherol content in deodorized oil B is preferably 50 to 600 ppm by mass, more preferably 50 to 550 ppm by mass, even more preferably 50 to 480 ppm by mass, and most preferably 80 to 350 ppm by mass.

The acid value of the deodorized oil B is 0.00 to 0.03, preferably 0.01 to 0.03, more preferably 0.02 or less, and most preferably 0.01 to 0.02.

Deodorized fats and oils B can be produced by chemical refining including an alkaline deoxidation step, or by physical refining not including an alkaline deoxidation step, and then subjected to a deodorization step. From the viewpoint of flavor, it is preferable to use chemical refining. Chemical refining is a refining method that includes a step of removing free fatty acids using an alkali in a deoxidation step, and is a method of refining, for example, crude oil pressed and extracted from a raw material by subjecting it to degumming, alkaline deoxidation, decolorization, dewaxing, and deodorization. In deodorized fats and oils B, general refining conditions for fats and oils can be used for the steps other than deodorization.

From the viewpoint of easily achieving the effects of the present invention, it is preferable that the deodorized oil B is a deodorized oil that has been subjected to an alkaline deoxidization treatment and a decolorization treatment and then a deodorization treatment.

In the present invention, one or more of soybean oil, corn oil, cottonseed oil, and sunflower oil are used as deodorized fat B. When a mixture of multiple fats and oils is used, they may be mixed at any stage of refining, but it is preferable to mix them after the deodorization treatment. Also, when blending fats and oils other than deodorized fat B, it is preferable to mix them after the deodorization treatment is completed.

The acid value of deodorized fats and oils B is reduced in the deodorization process, but it is also preferable to reduce it in alkaline deoxidation. The fats and oils used in alkaline deoxidation can be crude oils including water-degummed oils, fats and oils to which phosphoric acid has been added, or degummed oils to which phosphoric acid has been added and then the gums have been removed by centrifugation or the like. As the alkaline deoxidation method, it is preferable to add a 5-15% concentration aqueous sodium hydroxide solution in an amount equivalent to 0.8-1.8 times the amount of acid calculated from the acid value of the fats and oils, and then remove fatty acid soaps and the like by centrifugation or the like. It is more preferable to add an 8-13% concentration aqueous sodium hydroxide solution in an amount equivalent to 1.0-1.5 times the amount of free fatty acids. It is also more preferable to add and separate the aqueous sodium hydroxide solution two or more times. The process following the sodium hydroxide treatment is a decolorization process, and it is more preferable to wash the fats and oils with water after the sodium hydroxide treatment and then perform the decolorization process.

Also, as an alkaline deoxidation method, the Zenith process may be used, in which oil droplets are added from the bottom of a dilute alkaline solution (such as an aqueous sodium hydroxide solution) and neutralized as the oil droplets rise.

The production of deodorized oil B includes a process of deodorizing the deodorized oil so that the total tocopherol content and acid value in the deodorized oil satisfy the requirements, but these can be achieved by carrying out the deodorizing process under excessive conditions. The deodorization conditions are performed using a reduced pressure steam distillation apparatus, and can be performed at a higher temperature, under a higher vacuum, with a higher amount of steam, or for a longer period of time than the usual conditions for reduced pressure steam distillation. For example, when the deodorization is performed at a deodorization temperature of 200 to 280°C, a vacuum degree of 100 to 500 Pa, a steam amount of 1 to 8 mass% (relative to oil), and a deodorization time of 30 to 120 minutes, it is preferable to satisfy two or more conditions selected from a deodorization temperature of 235°C or higher, a vacuum degree of 500 Pa or lower, a steam amount of 2.0 mass% or higher (relative to oil), and a deodorization time of 50 minutes or longer, and more preferably to satisfy three conditions. The deodorization temperature is more preferably 245°C or higher, and even more preferably 250°C or higher. The degree of vacuum is preferably 400 Pa or less, more preferably 280 Pa or less, and even more preferably 260 Pa or less. The amount of water vapor is more preferably 2.4% by mass or more (relative to oil and fat), and even more preferably 3% by mass (relative to oil and fat). The deodorization time is more preferably 60 minutes or more, and even more preferably 70 minutes or more.

In the deodorizing step, the temperature is lowered at the end of the deodorizing process, and it is preferable to add citric acid at this time. Adding citric acid further increases oxidation stability. It is preferable to add 10 to 50 ppm of citric acid to the deodorized oil and fat, and more preferably 26 to 50 ppm. Since citric acid does not disperse or dissolve in oil as it is, it is preferable to add it as a 5 to 20 mass % aqueous solution.

(Deodorized oil C)
The deodorized oil C is a rapeseed deodorized oil having a total tocopherol content of 550 ppm or less and an acid value of 0.03 or less. The rapeseed oil may be oil extracted from a raw material cultivated and distributed as rapeseed. As the rapeseed variety, canola and/or high oleic acid canola may be used. The iodine value of the rapeseed oil is preferably 90 to 130, more preferably 95 to 120.

The total tocopherol content in deodorized oil C is preferably 100 to 550 ppm, more preferably 150 to 530 ppm, even more preferably 150 to 500 ppm, even more preferably 200 to 500 ppm, and most preferably 200 to 460 ppm. Furthermore, the gamma-tocopherol content in deodorized oil C is preferably 50 to 400 ppm, more preferably 100 to 400 ppm, and even more preferably 100 to 350 ppm.

The deodorized oil C has an acid value of 0.00 to 0.03, preferably 0.01 to 0.03, and more preferably 0.01 to 0.02.

The above deodorized oil C can be obtained by the same operation (production conditions) as the above-mentioned deodorized oil B.

(Other fats and oils)
The fats and oils in the cooking fat composition may contain fats and oils other than the adsorption-treated fats and oils, deodorized fats and oils A, deodorized fats and oils B, and deodorized fats and oils C. The fats and oils contained may be refined fats, partially refined fats and oils that have not been subjected to a deodorizing process, or unrefined fats and oils. In the case of refined fats and oils, it is preferable that the acid value of the composition in which all refined fats and oils are mixed is 0.03 or less. In addition, it is preferable that the partially refined fats and oils that have not been subjected to a deodorizing process and unrefined fats and oils are not contained in the cooking fat composition, and it is more preferable that they are not contained.

The oils and fats other than the above adsorption-treated oils and fats, deodorized oils and fats A, deodorized oils and fats B, and deodorized oils and fats C preferably contain less than 50% by mass of other refined oils and fats, more preferably less than 30% by mass. Examples include rice oil, sesame oil, safflower oil, peanut oil, olive oil, grapeseed oil, linseed oil, perilla oil, coconut oil, and oils obtained by fractionating these oils and fats. Also included are RBD palm-based oils and fats having a γ-tocotrienol content of more than 250 ppm or an acid value of more than 0.03. Further included are soybean oil, corn oil, cottonseed oil, and sunflower oil having a total tocopherol content of more than 850 ppm or an acid value of more than 0.03. Further included are rapeseed oils (canola oil, etc.) having a total tocopherol content of more than 550 ppm or an acid value of more than 0.03. These oils and fats may be used alone or in combination of two or more. Note that vegetable oils and fats including adsorption-treated oils and fats, deodorized oils and fats A, B, and C, as well as their interesterified oils and fractionated oils, are usually 95% by mass or more triglycerides.

In the present invention, it is preferable that the oils and fats other than the adsorption-treated oils and fats, deodorized oils and fats A, deodorized oils and fats B, and deodorized oils and fats C also have a high degree of purification. Therefore, it is preferable that the gamma-tocotrienol content in the oil and fat composition is 250 ppm or less. In addition, it is preferable that the total tocopherol content in the oil and fat composition is 900 ppm or less, more preferably 850 ppm or less, and even more preferably 550 ppm or less.

[Alkali metals]
The cooking oil and fat composition contains an alkali metal. The alkali metal is not particularly limited, but is preferably at least one selected from the group consisting of sodium and potassium. These alkali metals can be added as a component containing an alkali metal. In addition, an emulsifier containing an alkali metal produced using an alkali catalyst can be used. As the emulsifier, for example, polyglycerin fatty acid ester, sucrose fatty acid ester, sorbitan fatty acid ester, polyoxyethylene sorbitan monooleate, organic acid monoglyceride, mono fatty acid glyceride, etc. can be used. When an emulsifier containing an alkali metal is used, the alkali metal concentration in the emulsifier is preferably 10 to 50,000 ppm by mass. More preferably, it is 500 to 2,000 ppm by mass, and more preferably, it is 600 to 1,000 ppm by mass. The alkali metal concentration can be adjusted by adjusting the amount of catalyst during the esterification reaction to adjust the alkali metal concentration, or by appropriately adding an emulsifier that does not contain an alkali metal. In the cooking fat and oil composition of the present invention, the emulsifier and the component containing an alkali metal are preferably contained as a fatty acid monoglyceride containing an alkali metal.

Alternatively, the alkali metal-containing component may be a water-soluble or oil-soluble salt that can be used as a food additive, such as a sodium salt or potassium salt. Examples of sodium salts and potassium salts include, but are not limited to, sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, sodium bicarbonate, potassium bicarbonate, sodium malate, sodium citrate, potassium citrate, sodium L-ascorbate, sodium erythorbate, sodium L-glutamate, sodium succinate, potassium sorbate, sodium caseinate, sodium DL-tartrate, sodium stearoyl lactylate, sodium fatty acid, and potassium fatty acid. More preferably, it is a sodium fatty acid such as sodium oleate.

The content of alkali metal in the cooking oil composition of the present invention is 0.02 to 5.0 ppm by mass. When the content of alkali metal is 0.02 to 5.00 ppm by mass, it is possible to suppress the increase in acid value and/or the coloring during cooking by combining with the refined oil. The content of alkali metal is preferably 0.1 to 3.0 ppm by mass, and more preferably 0.1 to 2.5 ppm by mass.

[emulsifier]
Since alkali metals other than fatty acid soaps have poor solubility in fats and oils, it is preferable to add them by mixing them with an emulsifier. Alternatively, as described above for alkali metals, it is preferable to add them as a component of the emulsifier. As the emulsifier, for example, one or more selected from polyglycerin fatty acid esters, sucrose fatty acid esters, sorbitan fatty acid esters, polyoxyethylene sorbitan monooleates, organic acid monoglycerides, and mono fatty acid glycerides are preferable.

In order to incorporate an alkali metal into the oil composition for cooking, the amount of emulsifier contained in the oil composition for cooking is preferably 0.02 to 5.00% by mass. The content of the emulsifier is more preferably 0.02 to 0.09% by mass, even more preferably 0.03 to 0.09% by mass, and most preferably 0.04 to 0.08% by mass.

Moreover, it is preferable that the emulsifier has an HLB of 7 or less, since the emulsifier has high solubility in oils and fats.
HLB is an abbreviation for Hydrophile Lipophile Balance, and is an index for determining whether an emulsifier is hydrophilic or lipophilic, and takes a value of 0 to 20. The smaller the HLB value, the stronger the lipophilicity. In the present invention, the HLB value is calculated using the Atlas method. The Atlas method is as follows:
HLB=20×(1-S/A)
S: Saponification value
A: This refers to a method for calculating the HLB value from the neutralization value of the fatty acid in the ester.

In addition, the use of one or more emulsifiers selected from polyglycerol fatty acid esters with an HLB value of 3.5 or less, sucrose fatty acid esters with an HLB value of 3 or less, glycerol monooleate succinate, glycerol monooleate citrate, polyoxyethylene sorbitan monooleate, and mono fatty acid glycerides in which 47% by mass or more of the fatty acids constituting the glycerol monooleate are polyunsaturated fatty acids is preferable from the viewpoint of suppressing oil absorption of cooked foods during cooking such as frying, in addition to the effect of suppressing the increase in acid value and/or coloring during cooking according to the present application.

The amount of emulsifier to be added when suppressing oil absorption by cooked foods during cooking is 0.02 to 0.09% by mass, preferably 0.03 to 0.08% by mass, and more preferably 0.04 to 0.07% by mass, based on the oil/fat composition for cooking of the present invention.

The more preferred HLB value of the polyglycerol fatty acid ester is 3 or less, and the most preferred HLB value is 1 to 3. In addition, it is preferred that the constituent fatty acids of the polyglycerol fatty acid ester contain 5 to 50 mass% of unsaturated fatty acids having 8 to 22 carbon atoms in the constituent fatty acids, in order to reduce the amount of oil absorbed by the cooked object after heating. More preferably, the constituent fatty acids of the polyglycerol fatty acid ester contain 20 to 30 mass% of unsaturated fatty acids having 8 to 22 carbon atoms. Oleic acid, erucic acid, etc. can be used as the unsaturated fatty acids having 8 to 22 carbon atoms that constitute the polyglycerol fatty acid ester. The constituent fatty acids other than the unsaturated fatty acids are saturated fatty acids having 8 to 22 carbon atoms. In addition, the saturated fatty acids that can be used include lauric acid, myristic acid, palmitic acid, stearic acid, behenic acid, etc.

Sucrose fatty acid esters with an HLB value of 3 or less are preferably those with an HLB value of 1.5 to 3.0, and more preferably those with an HLB value of 1.8 to 2.5. If the HLB value of the sucrose fatty acid ester is 1.5 or more, the amount of oil absorbed by the cooked food after heating can be effectively reduced. On the other hand, if the HLB value of the sucrose fatty acid ester is 3.0 or less, there is a low possibility of separation occurring due to moisture absorption during storage. As the sucrose fatty acid ester, sucrose erucate ester is preferred.

For mono-fatty acid glycerides in which 47% by mass or more of the fatty acids constituting the glycerides are polyunsaturated fatty acids, it is preferable that 66% by mass or more of the fatty acids constituting the glycerides are unsaturated fatty acids. Examples of unsaturated fatty acids include oleic acid, linoleic acid, and linolenic acid, and oleic acid and linoleic acid are particularly preferable. In addition, among the fatty acids constituting the glycerides, it is preferable that the saturated fatty acids are 30% by mass or less, and more preferably 10 to 30% by mass. As the saturated fatty acid, palmitic acid is preferable. In this way, by using mono-fatty acid glycerides composed of many unsaturated fatty acids, especially many polyunsaturated fatty acids, it is possible to more reliably reduce the amount of oil absorbed by the food to be cooked.

The action of emulsifiers during the cooking of fried foods such as tempura is as follows. For example, when cooking tempura, the ingredients and batter (a mixture of tempura flour and water) are heated in high-temperature oil (160-200°C). When the batter comes into contact with the high-temperature oil, the water rapidly evaporates and disappears at the contact surface with the oil, and at the same time, the solid content in the batter, which is mainly composed of wheat flour, is baked and hardened. This phenomenon is repeated, and the water in the batter is gradually removed, forming a mesh-structured batter in which the wheat flour is baked and hardened in a shape with gaps. Emulsifiers affect the interfacial tension between air and liquid or liquid and liquid, and some emulsifiers change the interfacial tension between "oil and solid," "oil and water," or "oil and gas (water vapor)" when the batter is formed, thereby changing the properties of the batter (shape, ingredients, physical properties). Therefore, in the present invention, the effect of reducing the oil remaining in the food to be cooked after cooking is achieved by the emulsifier, regardless of the oil and fat components, and this effect is shown in JP 2015-119665 A or JP 2016-93128 A.

[Step of contacting oils and fats with ozone]
In the present invention, the refined oil and fat is a refined oil and fat that has been subjected to a process of contacting the oil and fat with ozone and a deodorizing process, thereby improving the flavor stability of the refined oil and fat. In particular, flavor deterioration due to exposure to light (light-exposed odor) can be suppressed. It is believed that the process of contacting the oil and fat with ozone decomposes the substances causing the light-exposed odor or changes them into compounds that are easily decomposed by distillation. Ozone is a gas composed of three oxygen atoms, and can be contacted by contacting ozone gas with the oil and fat, or by stirring water containing ozone with the oil and fat. Since it is not necessary to remove components other than ozone after contacting with ozone, it is preferable to contact ozone gas with the oil and fat. As a method for contacting ozone gas with the oil and fat, a method of contacting degassed oil and fat with ozone gas, a method of contacting ozone gas by bubbling ozone gas in the oil and fat, a method of contacting with water containing ozone, etc. can be used. The ozone generator is not particularly limited, but may be one that generates ozone by irradiating ultraviolet rays in the air or by colliding high-energy electrons with oxygen molecules, such as by silent discharge in oxygen. In addition, commercially available ozone generators for sterilizing, deodorizing, and decolorizing water and food may be used.

The longer the contact between the fats and oils and ozone, the greater the effect of improving the odor caused by exposure to light. It is preferable for the contact to be at least 1 minute, and more preferably between 2 minutes and 24 hours. It is even more preferable to contact the fats and oils with ozone for 3 minutes to 6 hours, and it is particularly preferable for the contact to be at least 10 minutes to 2 hours. The contact temperature may be any temperature at which the fats and oils are in a liquid state in order to bring the ozone into contact with the fats and oils, and is preferably at least -10°C, and more preferably at least 5°C. A higher contact temperature promotes the oxidation reaction of the fats and oils, making it difficult to control the reaction, so the contact temperature is preferably 180°C or lower, and more preferably 100°C or lower. It is even more preferable for the contact temperature to be 10 to 60°C, and most preferably 10 to 40°C.

The amount of ozone should be sufficient as long as ozone is dissolved in the oil and fat, and it is preferable that 0.0022 mass% or more of ozone is supplied to the oil and fat during the contact time, more preferably 0.006 mass% or more of ozone is supplied to the oil and fat, even more preferably 0.005 to 0.65 mass% of ozone is supplied to the oil and fat, and most preferably 0.006 to 0.65 mass% of ozone is supplied to the oil and fat.

Although it has been suggested that fatty acids such as linoleic acid and furan acid are the causative substances of the light-exposed odor, the cause is unknown. However, it is believed that all of these react with ozone to decompose or change into compounds that are easily decomposed in the deodorization process, so after the process of contacting the oil with ozone, deodorization is performed under conditions that allow these to be distilled off. Since peroxides in oils and fats decompose at the frying temperature, deodorization can be performed at 160°C or higher. In addition, if reduced pressure or steam distillation is used, the boiling point is lowered, so deodorization can be performed even at 120°C or higher. For deodorization, reduced pressure steam distillation, which is used in refining oils and fats, is preferable. On the other hand, since oils and fats may deteriorate in quality when heated to high temperatures, the upper limit of the deodorization temperature is preferably 260°C or lower. The deodorization temperature is preferably 120 to 260°C, more preferably 140 to 260°C or 160 to 260°C, and even more preferably 180 to 260°C or 200 to 260°C. In addition, by performing deodorization at a low temperature, the effect of improving the odor caused by exposure to light is also synergistically exhibited, so the deodorization temperature is preferably 120 to 230°C, more preferably 160 to 230°C or 160 to 225°C, even more preferably 180 to 230°C or 280 to 255°C, and even more preferably 200 to 255°C. The pressure during deodorization is under reduced pressure conditions, and the closer to vacuum the better. It is preferably 50,000 Pa or less, more preferably 8,000 Pa or less, and even more preferably 800 Pa or less. Note that the reduced pressure conditions are better as they are closer to vacuum, so there is no particular lower limit, but due to steam injection or equipment restrictions, it is often performed at 10 Pa or more. The pressure is preferably 10 to 1,000 Pa, more preferably 100 to 800 Pa, and even more preferably 200 to 600 Pa. The amount of water vapor during deodorization is preferably 0.5 to 10% by mass relative to the amount of oil and fat, and more preferably 1 to 5% by mass. A deodorization time of 15 minutes or more is sufficient, with 15 to 180 minutes being preferred, and 30 to 120 minutes being more preferred.

[Other ingredients]
Other ingredients can be added to the cooking oil and fat composition to the extent that the effect of the present invention is not impaired, and the type and amount of the ingredients to be added can be appropriately set according to the effect to be obtained. These ingredients are, for example, ingredients used in general oils and fats (food additives, etc.). These ingredients include, for example, antioxidants, antifoaming agents, crystallization inhibitors, etc., and are preferably added after deodorization and before filling.
Examples of antioxidants include tocopherols, ascorbic acids, flavone derivatives, kojic acid, gallic acid derivatives, catechin and its esters, butterbur, gossypol, sesamol, terpenes, etc. Examples of coloring components include carotene, astaxanthin, etc. Examples of antifoaming agents include silicone oil.

In the present invention, it is preferable to add silicone oil to the cooking oil composition so that the amount is 0.5 to 10 ppm by mass. The silicone oil content (mass ratio) in the oil composition is preferably 1 to 5 ppm by mass, and more preferably 2 to 3 ppm by mass. If the total silicone oil content is 0.5 ppm or more, the effect of suppressing foaming during cooking is sufficiently obtained. Also, if it exceeds 10 ppm, there will be a lot of foaming during cooking.

The silicone oil preferably has a dimethylpolysiloxane structure and a kinetic viscosity of 100 to 5000 mm ² /s at 25°C. The kinetic viscosity of the silicone oil is more preferably 500 to 2000 ^{mm 2} /s, even more preferably 800 to 1100 mm ² /s, and most preferably 900 to 1100 mm ² /s. The silicone oil may be commercially available for food applications. The "kinetic viscosity" referred to here refers to a value measured in accordance with JIS K 2283 (2000). It is also preferable to use a silicone oil that contains fine silica particles in addition to the silicone oil.

<Oil/fat composition for cooking>
The cooking oil/fat composition of the present invention contains 0.02 to 5 ppm by mass of alkali metal in the cooking oil/fat composition and 93% by mass or more of refined oil/fat having an acid value of 0.03 or less. The alkali metal, refined oil/fat, etc. are as described in the method for producing the cooking oil/fat composition described above. Note that the oil/fat is of natural origin, and at present, components other than free fatty acids that increase the acid value, and some coloring substances or substances that promote coloring have not been identified. Therefore, the acid value was used as an indicator to identify refined oil/fat having the effect of suppressing the increase in acid value during frying and/or heat coloring, which is the effect of the present invention.

The present invention will be described in detail below with reference to examples, but the present invention is not limited to these examples.

<Analysis method>
The analyses in each test were carried out according to the following methods.

(γ-tocotrienol content and total tocopherol content)
The gamma-tocotrienol content was measured under the conditions of "Standard Methods for Analysis of Fats, Oils and Related Materials 2.4.10-2013 Tocopherol (Fluorescence Detector - High Performance Liquid Chromatography)" established by the Japan Oil Chemists' Society, and the gamma-tocotrienol content was calculated. The total tocopherol content was calculated by measuring the alpha-tocopherol, beta-tocopherol, gamma-tocopherol, and delta-tocopherol in the deodorized oil in accordance with "Standard Methods for Analysis of Fats, Oils and Related Materials 2.4.10-2013 Tocopherol (Fluorescence Detector - High Performance Liquid Chromatography)" established by the Japan Oil Chemists' Society, and calculating the total content (percentage).

(Acid value)
The acid value was measured in accordance with the "Standard Method for Analysis of Fats, Oils and Related Compounds 2.3.1-2013 Acid Value" established by the Japan Oil Chemists' Society. The acid value indicates the amount of free fatty acids contained in the oil and is expressed as the number of milligrams of potassium hydroxide required to neutralize 1 g of sample oil.

(Iodine value)
The iodine value of fats and oils was measured in accordance with the "Standard Method for Analysis of Fats, Oils and Oils 2.3.4.1-2013 Iodine Value (Wiess-Cyclohexane Method)" established by the Japan Oil Chemists' Society. The higher the iodine value, the more double bonds there are.

(color tone)
The chromaticity of the test oil was measured using a Lovibond colorimeter (trade name "Lovibon PFX995", manufactured by The Tintometer Limited) with a 0.5 inch cell to measure the yellow chromaticity (Y value) and the red chromaticity (R value). Based on these results, "Y+10R" was calculated and evaluated. The smaller the Y+10R value, the lighter the color tone, and the larger the Y+10R value, the darker the color tone.

<Fly test>
Fry test 1 and fry test 2 in each test were carried out according to the following method.

(Fly Test 1)
4 L of each test oil was placed in a fryer and fried for 8 days (8 hours/day). The fried foods were cooked in the following order: potato tempura (2 days), croquettes (2 days), and fried chicken (4 days).
Sweet potato tempura: Every hour, eight slices of sweet potato were sliced to a thickness of 1 cm and dipped in batter (tempura flour (product name "Nissin Oishii Tempura Flour" manufactured by Nissin Foods Inc.):water = 1:1.6) and fried at 180°C for 3.5 minutes.
Croquettes: Every hour, four croquettes (product name "Nichirei Crispy Croquettes (Vegetables)" manufactured by Nichirei Foods Corporation) weighing 70 g each were fried at 180° C. for 4.5 minutes.
Deep-frying: Every hour, six chicken thighs (approximately 35 g each) were dipped in batter (deep-frying powder (product name "Deep-frying No. 1", manufactured by Nippon Shokken Co., Ltd.):water = 1:1) and deep-fried at 180°C for 4 minutes.

(Fly Test 2)
18 L of each test oil was placed in a fryer and fried. The fried potato tempura was cooked in the following manner, and the oil content of the potato tempura was extracted by the Soxhlet extraction method, and the oil content ratio in the potato tempura was calculated.
Imo-ten: Every hour, eight slices of sweet potato (approximately 5.5 cm in diameter) were sliced to a thickness of 1 cm and dipped in batter (tempura flour (product name "Nissin Oishii Tempura Flour" manufactured by Nissin Foods Inc.):water = 1:1.6) and fried at 180°C for 3.5 minutes.

<Emulsifier>
The emulsifiers 1 to 4 used are as follows.
Emulsifier 1: Polyglycerol fatty acid ester (product name "THL-15", manufactured by Sakamoto Pharmaceutical Co., Ltd., HLB 2.9, amount of unsaturated fatty acids having 8 to 22 carbon atoms in the constituent fatty acids: 26.5% by mass)
Emulsifier 2: Decaglycerin oleate (product name "Ryoto Polyglycerol O-50D", manufactured by Mitsubishi Chemical Foods Corporation, HLB 7)
Emulsifier 3: Decaglycerin decaoleate (product name "DAO-7S" Sakamoto Pharmaceutical Industry Co., Ltd. (HLB 3.5)
Emulsifier 4: Diglycerol oleate (mono-diester, product name "Sunsoft Q-17B", HLB 6.5)

<Test 1: Preparation of test oil and heating test>
(Oils and fats 1)
Bleached rapeseed oil (canola variety, iodine value 113) was deodorized at 250°C, 667 Pa, steam amount: 3.0% relative to oil, and for 80 minutes to obtain deodorized oil 1 (acid value 0.04). Silicone oil ("KF-96ADF-1,000CS" manufactured by Shin-Etsu Chemical Co., Ltd.) was added to the deodorized oil 1 at 3 ppm relative to the deodorized oil 1 to obtain oil 1.

(Oils and fats 2)
Bleached rapeseed oil (canola variety, iodine value 113) was deodorized at 250°C, 467 Pa, steam amount: 3.0% relative to oil, and for 80 minutes to obtain deodorized oil 2 (acid value 0.02). Silicone oil ("KF-96ADF-1,000CS" manufactured by Shin-Etsu Chemical Co., Ltd.) was added to the deodorized oil 2 at 3 ppm relative to the deodorized oil 2 to obtain oil 2.

(Test oil 1, 2, 1-1 to 5, 2-1 to 5)
Oil 1 was designated as test oil 1, and oil 2 was designated as test oil 2. Furthermore, emulsifiers were added to oil 1 and oil 2 as shown in Table 2 to obtain test oils 1-1 to 5 and 2-1 to 5.

(Heating test)
50 g of the test oil was placed in a beaker (IWAKI Pyrex 200 mL beaker) and heated at 185°C for 8 hours. The acid value was measured before and after the heating test. The results are shown in Table 2. The beaker used was a new one that had been thoroughly washed with detergent and then with ion-exchanged water.

As shown in Table 2, the acid value increase after the heating test was suppressed for test oils 2-1 to 5 compared to test oils 1 and 2. Also, the acid value increase after the heating test was suppressed compared to test oils 1-1 to 5.

<Test 2: Preparation of test oil and frying test 1>
(Test oils 1, 2, 2-6)
The oil 1 used in Test 1 was designated as Test Oil 1, and the oil 2 was designated as Test Oil 2. Furthermore, an emulsifier was added to the oil 2 as shown in Table 3 to obtain Test Oil 2-6.

(Fly Test 1)
Frying test 1 was carried out with each test oil. The acid value and color of the test oil before and after frying are shown in Table 3.

As shown in Table 3, test oils 2-6 had a lower acid value after the heating test compared to test oils 1 and 2. Heat discoloration was also suppressed.

<Test 3: Preparation of test oil and frying test 2>
(Test oils 1, 2, 1-5 to 7, 2-6)
The oil 1 used in Tests 1 and 2 was designated as Test Oil 1, and the oil 2 was designated as Test Oil 2. Furthermore, emulsifiers were added to the oils 1 and 2 as shown in Table 4 to obtain Test Oils 1-5 to 7 and 2-6 (Test Oil 2-6 was the same as that used in Test 2).

(Fly Test 2)
Frying test 2 was carried out with each test oil. The oil content in the potato tempura was calculated, and the results are shown in Table 4.

As shown in Table 4, test oils 1-5 and 2-7 have the ability to inhibit oil absorption in fried foods, but test oil 1-7, which contains a large amount of emulsifier, loses its ability to inhibit oil absorption in fried foods. Furthermore, test oils 1-5 and 2-7 show that the function of reducing the amount of oil remaining in foods after cooking is achieved by the emulsifier, regardless of the oil components, so refined oils with an acid value of 0.03 or less other than oil 2 can also inhibit oil absorption in fried foods.

<Reference Example 1: Effect of inhibiting increase in acid value and/or coloring of adsorption-treated oils and fats>
(Preparation of refined oil 1)
To refined canola oil (acid value 0.04), a silica-magnesia-based preparation (Mizusawa Chemical Industry Co., Ltd., "Mizuka Life F-2G": about 55% silica, about 32% magnesia, about 13% water), silicon dioxide (Fujifilm Wako Pure Chemical Industries, Ltd.), and magnesium oxide (Fujifilm Wako Pure Chemical Industries, Ltd.) were added in an amount of 1% by mass relative to the refined canola oil, stirred at room temperature for 6 hours, and then filtered to obtain each refined oil. The acid values of each refined oil are shown in Table 5.

As shown in Table 5, refined oil 2 had a lower acid value than refined oils 3 and 4, and refined oils 3 and 4 were no different from refined oil 1, which had not been subjected to adsorption treatment.

(Preparation of refined oils and fats 2)
The bleached canola oil was deodorized at 250° C. for 60 minutes at 4.5 torr with a steam amount of 3% by mass relative to the oil to obtain refined oil A (acid value 0.04, color tone 0.3).

Silicone oil (KF-96ADF-1,000CS, Shin-Etsu Chemical Co., Ltd.) was added to deodorized oil A in an amount of 3 ppm by mass relative to refined oil A to obtain refined oil A-1.

1% by mass of a silica-magnesia based preparation (Mizuka Life F-2G, manufactured by Mizusawa Chemical Industry Co., Ltd.: approximately 55% silica, approximately 32% magnesia, approximately 13% water) was added to refined oil A, and the mixture was stirred at 20°C for 1 hour and filtered to obtain refined oil B. 3 ppm by mass of silicone oil (KF-96ADF-1,000CS, manufactured by Shin-Etsu Chemical Co., Ltd.) was added to refined oil B to obtain refined oil B-1.

(Fly Test)
Frying test 1 was carried out with each test oil, and the acid value and color tone of the oils and fats after the frying test are shown in Table 6.

As shown in Table 6, it was confirmed that refined oil B-1 has a lower acid value as a refined oil compared to refined oil A-1, and that the increase in acid value and heat discoloration after frying are suppressed. Because refined oil B-1 has a lower acid value than the oil used in Example 1, the addition of an alkali metal as in Example 1 is expected to produce effects greater than those of Example 1.

<Reference Example 2: Effect of ozone contact step>
(Preparation of refined oil O-1)
1.2 kg of bleached soybean oil (undistilled oil 1) was deodorized (255° C., 533 Pa, 60 minutes, steam amount 2.7% based on the oil) to obtain refined oil O-1.
(Preparation of refined oil O-2)
Ozone generated by an ozone generator (GL-3188A: manufactured by Shenzhen Guanglei Electronic Co., Ltd., ozone generation rate 400 mg/h) was blown into 1.5 kg of soybean bleached oil (undistilled oil 1) at room temperature for 0.25 minutes through a glass tube having a microhole, to obtain undistilled oil 2.
Further, 1.2 kg of the undistilled oil 2 was deodorized (255° C., 533 Pa, 60 minutes, water vapor amount: 2.7% based on the oil and fat) to obtain refined oil O-2.
(Preparation of refined oil O-3)
Ozone generated by an ozone generator (GL-3188A: manufactured by Shenzhen Guanglei Electronic Co., Ltd., ozone generation rate 400 mg/h) was blown into 1.5 kg of soybean bleached oil (undistilled oil 1) through a glass tube having microholes at room temperature for 3 minutes to obtain undistilled oil 3.
Further, 1.2 kg of the undistilled oil 3 was deodorized (255° C., 533 Pa, 60 minutes, water vapor amount: 2.7% based on the oil and fat) to obtain refined oil O-3.
(Preparation of refined oil O-4)
Ozone generated by an ozone generator (GL-3188A: manufactured by Shenzhen Guanglei Electronic Co., Ltd., ozone generation rate 400 mg/h) was blown into 1.5 kg of soybean bleached oil (undistilled oil 1) through a glass tube having microholes at room temperature for 15 minutes to obtain undistilled oil 4.
Further, 1.2 kg of the undistilled oil 4 was deodorized (255° C., 533 Pa, 60 minutes, water vapor amount: 2.7% based on the oil and fat) to obtain refined oil O-4.

(Light Exposure Test 1)
200 g of each of distilled fats and oils 1 to 4 was placed in a 300 ml Erlenmeyer flask and exposed to fluorescent light (1000 lux, 70 hours). The odor of exposure to light was evaluated. The odor of exposure to light was evaluated by placing 40 g of fats and oils in a 100 ml beaker, heating the oils to 120°C, and a panel of 15 experts evaluated the odor and calculated the average score. The results are shown in Table 7. The evaluation was performed by assigning 10 points to the heated odor of the distilled fat and oil 1 exposed to light, and 0 points to the unexposed distilled fat and oil 1 that did not have an odor of exposure to light.

※は有意差あり（ｐ＜０．０１）

* indicates significant difference (p<0.01)

From Table 7, it was confirmed that the odor of oils exposed to light was improved by treating the oils with ozone. In particular, it was found that refined oils O-3 and O-4 had a significant effect. This effect is due to the treatment of the oils and fats themselves, and it is expected that the odor of oils and fats exposed to light can be improved by reducing the acid value of the oils and fats after ozone treatment and adding an alkali metal, without compromising the effect of suppressing the increase in acid value and/or coloring of the oil and fat composition for cooking during cooking, which is derived from the process of reducing the acid value and the alkali metal.

Claims (7)

A method for producing an oil/fat composition for cooking, comprising a step of adding an alkali metal and an emulsifier, and/or an emulsifier containing an alkali metal, to the refined oil/fat, the oil/fat contained in the oil/fat composition for cooking being 93 mass% or more and the alkali metal being 0.02 to 5.0 mass ppm in the oil/fat composition for cooking, the method including the step of contacting the refined oil/fat with ozone prior to the deodorizing step. The method for producing a cooking oil and fat composition according to claim 1, wherein the emulsifier is one or more selected from polyglycerin fatty acid esters, sucrose fatty acid esters, sorbitan fatty acid esters, polyoxyethylene sorbitan monooleate, organic acid monoglycerides, and mono fatty acid glycerides. The method for producing a cooking oil composition according to claim 1 or 2, wherein the emulsifier is contained in the cooking oil composition at 0.02 to 5.00% by mass. The method for producing a cooking oil and fat composition according to any one of claims 1 to 3, wherein the emulsifier is one or more selected from polyglycerol fatty acid esters having an HLB value of 3.5 or less, sucrose fatty acid esters having an HLB value of 3 or less, glycerol monooleate succinate, glycerol monooleate citrate, polyoxyethylene sorbitan monooleate, and mono fatty acid glycerides in which 47% by mass or more of the fatty acids constituting the mono fatty acid glyceride are polyunsaturated fatty acids. The method for producing a cooking oil composition according to any one of claims 1 to 4, wherein the refined oil is subjected to an adsorption process in which the refined oil is brought into contact with a silica-magnesia-based preparation in a liquid state at a temperature of less than 80°C after the deodorization process. The method for producing a cooking oil composition according to claim 5, wherein the refined oil has an acid value of 0.00 to 0.01. The method for producing a cooking oil composition according to any one of claims 1 to 6 further comprises adding silicone oil to the cooking oil composition at a concentration of 0.5 to 10 ppm by mass.