Production method of edible oil and fat, method for preventing deterioration of edible oil and fat, and production device of edible oil and fat

Abstract

To provide a production method of edible oil and fat, a method for preventing deterioration of edible oil and fat, and a production device of edible oil and fat which enable further prevention of edible oil deterioration.SOLUTION: A production method of edible oil and fat includes: bubble dispersion step S2 of performing bubble dispersion treatment to disperse bubbles of an inert gas having a diameter of 1 μm or less to extracted or purified edible oil and fat; and pressurization step S4 of performing pressurization treatment to apply a pressure 0.01 MPa or more and 0.15 MPa or less higher than atmospheric pressure to the edible oil and fat having the dispersed bubbles by the bubble dispersion step S2 for 20 seconds or longer.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a method for producing edible oils and fats, a method for suppressing deterioration of edible oils and fats, and an apparatus for producing edible oils and fats. [Background technology]

[0002] In recent years, the Sustainable Development Goals (SDGs) have been set as international goals aiming for a sustainable and better world by 2030. As a result, as part of efforts to achieve these goals, the food industry is also working to reduce the amount of food waste caused by expired food by preventing quality deterioration, etc. It is known that edible oils and fats deteriorate in quality (oxidation of the oils and fats) when they come into contact with oxygen in the air. For this reason, oxygen is removed from edible oils and fats with inert gases such as nitrogen to improve the shelf life of edible oils and fats in sealed containers. However, when the container is opened, the edible oils and fats come into contact with oxygen in the air, and deterioration of the quality of the edible oils and fats is unavoidable. For example, one method for producing edible oils and fats that removes oxygen from edible oils and fats is to inject (disperse) inert gas bubbles into the edible oils and fats (see Patent Documents 1 and 2). In this method for producing edible oils and fats, inert gas bubbles are injected into the edible oils and fats to remove the oxygen dissolved in the oils and fats, thereby making it possible to suppress deterioration in the quality of the edible oils and fats. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2022-128636 A [Patent Document 2] JP 2022-184171 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, even in the case of edible oils and fats produced by conventionally injecting an inert gas, although the deterioration of quality can be suppressed to some extent when the product is unopened, a method for further suppressing the deterioration of quality is required.

[0005] Therefore, an object of the present invention is to provide a method for producing edible oils and fats, a method for suppressing the deterioration of edible oils and fats, and an apparatus for producing edible oils and fats, which can further suppress the deterioration of edible oils and fats. [Means for solving the problem]

[0006] As a result of intensive research, the inventors have found that the above-mentioned problems can be solved by dispersing bubbles of an inert gas into edible oil or fat and then pressurizing the edible oil or fat with the bubbles dispersed therein, and have thus completed the present invention.

[0007] That is, the present invention provides the following [1] to [9]. [1] A bubble dispersion process for dispersing inert gas bubbles into edible oils and fats; and a pressurizing step of pressurizing the edible oil and fat in which the air bubbles are dispersed. [2] The method for producing edible fats and oils according to [1], characterized in that the pressurizing step is a step of applying a pressure that is 0.01 MPa or more higher than atmospheric pressure. [3] The method for producing edible fats and oils according to [1] or [2], characterized in that the pressurizing step is a step of applying a pressure that is 0.03 MPa or more and 0.15 MPa or less higher than atmospheric pressure. [4] The method for producing edible fats and oils according to any one of [1] to [3], characterized in that the inert gas is one or more gases selected from nitrogen gas, carbon dioxide gas, argon gas, helium, and nitrous oxide gas. [5] The method for producing edible oil or fat according to any one of [1] to [4], characterized in that the amount of the bubbles of the inert gas dispersed in the bubble dispersion step is 0.05 times or more the volume of the edible oil or fat. [6] The method for producing edible fats and oils according to any one of [1] to [5], wherein the air bubbles dispersed in the air bubble dispersion step include air bubbles having a diameter of 1 μm or less. [7] The method for producing edible oils and fats described in [6], characterized in that the edible oils and fats after the air bubble dispersion step contain air bubbles having a diameter of 0.8 μm or less 5 hours after the air bubble dispersion step. [8] A bubble dispersion step of dispersing inert gas bubbles into the edible oil or fat; a pressurizing step of pressurizing the edible oil or fat in which the air bubbles are dispersed. [9] A bubble dispersion unit that disperses inert gas bubbles into the edible oil and fat; and a pressurizing section that pressurizes the edible oil and fat in which the air bubbles are dispersed. Effect of the Invention

[0008] The method for producing edible oils and fats, the method for suppressing deterioration of edible oils and fats, and the apparatus for producing edible oils and fats according to the present invention can suppress deterioration of edible oils and fats more effectively than conventional edible oils and fats in which an inert gas is dispersed, etc. Furthermore, deterioration of edible oils and fats even after the container is opened can also be suppressed. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a configuration diagram showing an example of the configuration of an edible oil and fat manufacturing apparatus according to one embodiment of the present invention. [Diagram 2] 1 is a flowchart showing an edible oil and fat production operation. [Diagram 3] 1 is a table showing test results of a deterioration test. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] An embodiment of the present invention will be described below. In the embodiment of the present invention, A (numerical value) to B (numerical value) means A or more and B or less. In addition, the preferred and more preferred aspects exemplified below can be used in appropriate combination with each other regardless of expressions such as "for example," "preferable," and "more preferable." In addition, the description of the numerical range is an example, and the range obtained by appropriately combining the upper and lower limits of each range and the numerical values ​​of the examples can also be preferably used (for example, when A to B or C to D is described, the combination of A to D or C to B can be used). Furthermore, the terms "contain" or "include" may be read as "essentially consisting of" or "consisting only of."

[0011] [Method of producing edible oils and fats] A method for producing edible oil or fat according to one embodiment of the present invention is characterized by carrying out a bubble dispersion step of dispersing inert gas bubbles into edible oil or fat, and a pressurizing step of pressurizing the edible oil or fat in which the bubbles have been dispersed.

[0012] (edible fats and oils) The edible oils and fats to be used in the edible oil and fat production method of the present embodiment may be animal and vegetable oils and fats, microbial oils and fats, oils and fats synthesized from glycerin and fatty acids, fractionated oils and fats thereof, interesterified oils and fats, hydrogenated oils and fats, etc., which may be used alone or in combination. In addition, those which are liquid at 5°C are preferred. Examples of the animal and vegetable oils include soybean oil, rapeseed oil, sunflower oil, olive oil, 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, palm kernel oil, etc. Fractionated oils of these oils (e.g., palm olein, palm superolein, palm stearin, palm midfraction, and other palm oil fractions) can also be used. The vegetable oils may be vegetable oils obtained from plant varieties with a high or low specific fatty acid content (e.g., canola oil, high oleic canola oil, high oleic soybean oil, vegetable oils with a high n-3 fatty acid content, high oleic palm oil, etc.). Microbial oils include oils produced from microorganisms such as yeast and algae. Examples of fats and oils synthesized from glycerin and fatty acids include fats and oils containing linear saturated fatty acids having 6 to 12 carbon atoms, preferably 8 to 10 carbon atoms, such as medium chain triglycerides (MCT) having 8 to 10 carbon atoms. Interesterified fats and oils are fats and oils that have undergone interesterification using fats and oils as raw materials. For example, interesterified fats and oils between palm oil or palm oil fractions and other liquid fats, or interesterified fats and oils between MCT and vegetable oils, etc. can be used. Examples of the hydrogenated oils and fats include hydrogenated oils and fats of animal and vegetable oils and fractionated oils and fats of animal and vegetable oils, as well as hydrogenated oils and fats of interesterified oils and fats.

[0013] The edible oil or fat that is the subject of the edible oil or fat production method of this embodiment can be unrefined oil or fat, or refined oil or fat. The refined oils and fats to be used may be those that have undergone one or more refining steps, such as a degumming step, a deacidification step, a bleaching step, a deodorization step, and a dewaxing step, and it is preferable that the refined oils and fats have not undergone a degumming step, a deacidification step, or a bleaching step after the deodorization step. Unrefined oils and fats are oils and fats that have not undergone the above-mentioned refining process. Examples of unrefined oils and fats include virgin oils that are characterized by a flavor derived from raw materials such as olive oil and camellia oil, as well as roasted oils and fats that are characterized by a roasted flavor, such as roasted sesame oil, roasted rapeseed oil, and roasted peanut oil. In addition, as the unrefined oil, virgin oils or roasted oils and fats that have undergone one or more processes selected from a process of removing solids by filtration, static separation, centrifugation, etc., a water washing process, and a drying process can also be used.

[0014] (inert gas) The inert gas used in the method for producing edible fats and oils of this embodiment is a gas that does not undergo a chemical reaction with fats and oils, and in particular, is a gas that does not undergo an oxidation reaction. For example, the inert gas may be one or more gases selected from nitrogen gas, carbon dioxide gas, argon gas, helium, and nitrous oxide gas. Nitrogen gas and / or carbon dioxide gas are preferred from the viewpoint of availability, and nitrogen gas is more preferred from the viewpoint of ease of handling.

[0015] (Air bubble dispersion process) In the bubble dispersion step in the method for producing edible oils and fats of this embodiment, bubbles of an inert gas are dispersed in the edible oils and fats. The method for dispersing bubbles in the bubble dispersion step is not particularly limited. For example, a line mixer may be installed in the middle of a pipe to disperse bubbles in the edible oils and fats moving in the pipe, or a pipe with fine holes through which an inert gas is ejected may be installed at the bottom of a container (tank, etc.) containing the edible oils and fats to disperse the bubbles. In the present invention, it is preferable to disperse fine bubbles, and in this case, a microbubble generator such as a swirling liquid flow type, static mixer type, fine hole type, ejector type, Venturi type, or pressure dissolution type (reduced pressure precipitation type) or an ultrafine bubble generator such as a swirling liquid flow type, static mixer type, or pressure dissolution type can be used.

[0016] The amount of bubbles of the inert gas dispersed in the bubble dispersion step is not particularly limited, but is preferably 0.05 times or more the volume of the edible oil or fat. The larger the amount, the more bubbles are expected to remain in the edible oil or fat, and this is preferable. The amount of bubbles of the inert gas dispersed is more preferably 0.1 times or more the volume of the edible oil or fat, and more preferably 0.3 times or more. If the amount of bubbles dispersed in the bubble dispersion step is too large, causing defects in the delivery of the edible oil or fat, the amount of bubbles dispersed may be limited to 1.2 times or less the volume of the edible oil or fat, and is preferably 1.0 times or less.

[0017] The smaller the particle size of the inert gas bubbles in the bubble dispersion process, the more likely they are to remain in the edible oil or fat without being lost, but it is sufficient that the particle size is such that the bubbles can be kept dispersed in the oil or fat in the subsequent pressurization process. For example, the particle size (diameter) of the inert gas bubbles preferably includes those of 1 μm or less, more preferably those of 0.8 μm or less, and further preferably those of 0.4 μm or less.

[0018] In addition, it is preferable that the edible oil and fat after the air bubble dispersion process has inert gas bubbles with a particle diameter of 1 μm or less remaining in the oil and fat after the next pressurizing process, or the pressurizing process and the filling process. For example, it is more preferable that the edible oil and fat after the air bubble dispersion process has inert gas bubbles with a particle diameter of 0.8 μm or less remaining, and more preferably, inert gas bubbles with a particle diameter of 0.4 μm or less remaining 5 hours after the air bubble dispersion process. The particle diameter in the oil and fat can be measured by a laser X-ray diffraction scattering method, and for example, SALD-7500nano of Shimadzu Corporation can be used.

[0019] (Pressure process) In the pressurizing step in the method for producing edible oil and fat of this embodiment, the edible oil and fat in which air bubbles are dispersed is pressurized through the above-mentioned air bubble dispersion step. The pressurizing method in the pressurizing step is not particularly limited, but for example, the edible oil and fat is pressurized by sending the edible oil and fat to a container such as a tank containing the edible oil and fat using a pressurizing pump. Alternatively, compressed gas is sent into the tank to pressurize the edible oil and fat. The compressed gas is preferably a compressed inert gas such as compressed nitrogen, but compressed air can also be used. In the case of compressed air, it is preferable to introduce it into the head space of the container so that air bubbles do not enter the oil and fat.

[0020] The pressure applied in the pressurizing step is indicated as a pressure (gauge pressure) with atmospheric pressure set as the standard (0 MPa). A higher pressure is preferable, and for example, it is preferable to apply a pressure 0.01 MPa or more higher than atmospheric pressure to the edible oil and fat in which air bubbles are dispersed in the pressurizing step. If the pressurizing pressure is too high, the device becomes complicated. Therefore, it is more preferable to apply a pressure 0.03 MPa to 0.15 MPa higher than atmospheric pressure to the edible oil and fat in which air bubbles are dispersed in the pressurizing step, and even more preferable to apply a pressure 0.03 MPa to 0.1 MPa higher than atmospheric pressure to the edible oil and fat in which air bubbles are dispersed.

[0021] Since it is considered that some of the bubbles of the inert gas are instantly dissolved in the edible oil by the pressurization, the time for which pressure is applied to the edible oil in which the bubbles are dispersed in the pressurization step is not particularly limited. For example, it may be 1 second or more, preferably 10 seconds or more, more preferably 15 seconds or more, and even more preferably 20 seconds or more. If it is 1 second or more, it is considered that the dissolution equilibrium of the inert gas in the edible oil is reached, so there is no particular upper limit, but it is preferably 120 minutes or less, more preferably 10 minutes or less, and particularly preferably 1 minute or less.

[0022] [Method of preventing deterioration of edible oils and fats] The method for suppressing deterioration of edible oils and fats according to one embodiment of the present invention is characterized by carrying out an air bubble dispersion step of dispersing air bubbles of an inert gas into the edible oil and fat, and a pressurizing step of pressurizing the edible oil and fat with the air bubbles dispersed therein. Details of the edible oil and fats, the inert gas, the air bubble dispersion step, the pressurizing step, etc. are as described in the above-mentioned [Method for producing edible oils and fats].

[0023] [Edible oil and fat manufacturing equipment] The edible oil / fat manufacturing apparatus according to one embodiment of the present invention is characterized by comprising an air bubble dispersion unit that disperses inert gas bubbles into the edible oil / fat, and a pressurizing unit that pressurizes the edible oil / fat with the air bubbles dispersed in. Details of the edible oil / fat, inert gas, air bubbles, air bubble dispersion, pressurization, etc. are as described in the above-mentioned [Method for manufacturing edible oil / fat].

[0024] (Configuration of edible oil manufacturing equipment) Hereinafter, an edible oil / fat manufacturing apparatus according to one embodiment of the present invention (hereinafter referred to as edible oil / fat manufacturing apparatus) will be described with reference to the accompanying drawings. This edible oil / fat manufacturing apparatus manufactures containerized edible oil / fat by subjecting unrefined edible oil / fat and / or refined edible oil / fat to a deterioration inhibition treatment and then carrying out a filling process. In particular, this edible oil / fat manufacturing apparatus employs a configuration in which an air bubble dispersion process and a pressurization process are carried out on the edible oil / fat as deterioration inhibition treatments. It should be noted that this edible oil / fat manufacturing apparatus is an example of an edible oil / fat manufacturing apparatus, and also an example of an edible oil / fat deterioration inhibition processing apparatus that carries out a deterioration inhibition process on the edible oil / fat.

[0025] 1, the edible oil and fat production apparatus 1 includes a storage tank 11 for storing unrefined edible oil and fat or refined edible oil and fat, an air bubble dispersion section 12 for performing an air bubble dispersion treatment on the edible oil and fat, a pressurizing section 13 for performing a pressurizing treatment on the edible oil and fat, and a filling section 14 for filling a container C with the edible oil and fat that has been subjected to the air bubble dispersion treatment and pressurizing treatment. The edible oil and fat production apparatus 1 also includes a first flow path piping 21 for sending the edible oil and fat from the storage tank 11 to the air bubble dispersion section 12, a second flow path piping 22 for sending the edible oil and fat from the air bubble dispersion section 12 to the pressurizing section 13, a third flow path piping 23 for sending the edible oil and fat from the pressurizing section 13 to the filling section 14, and a liquid sending pump 24 for applying a liquid sending pressure to the edible oil and fat in the flow path from the storage tank 11 to the pressurizing section 13. The edible oil stored in the storage tank 11 is sent from the upstream side to the first flow path piping 21, the bubble dispersion section 12, the second flow path piping 22, and the pressurizing section 13 by the liquid sending pressure of the liquid sending pump 24. The edible oil in the pressurizing section 13 is sent to the filling section 14 via the third flow path piping 23 by the pressure of the pressurizing section 13.

[0026] The air bubble dispersion unit 12 is composed of, for example, a static mixer (a static mixer type line mixer), and disperses inert gas bubbles into edible oil (for example, at a flow rate of 50 to 600 L / Min) that is supplied from the storage tank 11 through the first flow path piping 21 and sent through the flow path in the air bubble dispersion unit 12 (air bubble dispersion process). For example, the air bubble dispersion unit 12 generates air bubbles including inert gas bubbles with a diameter of 1 μm or less (so-called ultrafine bubbles), and mixes and disperses the generated inert gas bubbles into the edible oil. In addition, the amount of air bubbles dispersed in the air bubble dispersion process is preferably, for example, 0.05 times or more the volume of the edible oil. In addition, the amount of air bubbles dispersed in the air bubble dispersion process is more preferably 0.3 times or more the volume of the edible oil.

[0027] The pressurizing unit 13 is composed of, for example, a pressurizing tank 31 having a capacity of 50 kg to 5 t and a pressure gauge 32, and pressurizes the edible oil and fat in which the inert gas is dispersed (pressurizing process). For example, the pressurizing unit 13 pressurizes the edible oil and fat with compressed gas while the edible oil and fat is contained in the pressurizing tank 31. The pressure at which the edible oil and fat is pressurized in the pressurizing process is preferably, for example, 0.01 MPa or more higher than atmospheric pressure. In addition, the pressure at which the edible oil and fat is pressurized in the pressurizing process is preferably 0.03 MPa or more higher than atmospheric pressure.

[0028] Moreover, the pressurizing unit 13 preferably applies the above pressure to the edible oil and fat for, for example, 20 seconds or more. When the edible oil and fat are received into the pressurized tank 31 and the edible oil and fat are delivered from the pressurized tank 31 in a pressurized state, the average time for the edible oil and fat received into the pressurized tank 31 to be delivered from the pressurized tank 31 can be adjusted by adjusting the flow rate (flow velocity) of the edible oil and fat in the second flow path piping 22 and the third flow path piping 23.

[0029] It is preferable that the pressurization process by the pressurization unit 13 is performed in a state where the air in the head space (space not filled with edible oil or fat) of the pressurization tank 31 is replaced with an inert gas. This makes it possible to prevent the edible oil or fat from coming into contact with air (particularly oxygen) during the pressurization process by the pressurization unit 13.

[0030] The filling unit 14 has a filling nozzle 41, and fills the container C with edible oil that has been subjected to air bubble dispersion treatment and pressurization treatment. The filling unit 14 also has a gas replacement unit and a capping unit (both not shown), and in the filling process by the filling unit 14, it is preferable that after the filling nozzle 41 fills the container C with edible oil, the gas replacement unit replaces the air in the head space (space not filled with edible oil) of the container C with an inert gas, and then the capping unit caps the container C. In this way, the edible oil is stored in the container C without coming into contact with air, and containerized edible oil is produced.

[0031] (Edible oil production operation) Next, an edible oil production operation by the edible oil production apparatus 1 will be described with reference to Fig. 2. This edible oil production operation is performed from a state in which edible oil is stored in the storage tank 11, and is an operation for subjecting the edible oil to a deterioration suppression treatment. Note that this edible oil production operation is an example of a method for producing edible oil and an example of a method for suppressing deterioration of edible oil.

[0032] 2, in the edible oil / fat production operation, first, the edible oil / fat stored in the storage tank 11 is sent to the air bubble dispersion section 12 by the liquid sending pressure of the liquid sending pump 24 (S1), and the air bubble dispersion section 12 performs an air bubble dispersion process on the edible oil / fat (S2) (air bubble dispersion step). For example, it is preferable to disperse inert gas bubbles into the edible oil / fat in an amount of 0.05 or more times the volume of the edible oil / fat.

[0033] After the inert gas bubbles are dispersed in the edible oil, the edible oil with the dispersed inert gas bubbles is sent to the pressurizing unit 13 (S3), and the edible oil is pressurized by the pressurizing unit 13 (S4) (pressurizing step). The pressure applied in the pressurizing process is indicated as a gauge pressure with atmospheric pressure as the reference (0 MPa), and the pressure applied in the pressurizing process is preferably at least 0.01 MPa higher than atmospheric pressure (gauge pressure 0.01 MPa or more).

[0034] Once the edible oil and fat have been pressurized, the edible oil and fat that have been subjected to the air bubble dispersion treatment and pressurization treatment are sent to the filling unit 14 (S5), and the filling unit 14 performs a filling process on the edible oil and fat (S6). That is, after the edible oil and fat are filled into the container C, the air in the head space of the container C is replaced with an inert gas, and then the container C is capped. This produces edible oil and fat in the container C. This marks the end of the edible oil and fat production operation.

[0035] [Examples, Deterioration test of edible oils and fats and residual air bubbles test of edible oils and fats] (Example) Next, examples (Example 1 to Example 7) that are specific examples of the above embodiment will be described. Each example conforms to the above embodiment unless otherwise specified.

[0036] In the first embodiment, in the air bubble dispersion process, nitrogen gas bubbles were dispersed into the edible oil in an amount of 0.6 times the volume of the edible oil, and in the pressurization process, the edible oil with the dispersed air bubbles was pressurized at a pressure 0.1 MPa higher than atmospheric pressure (gauge pressure 0.1 MPa) for an average of approximately 20 seconds, and then the edible oil that had been subjected to the air bubble dispersion process and the pressurization process was filled.

[0037] In the second to fourth examples, the pressure in the pressurization treatment was changed from that in the first example. In the second example, in the air bubble dispersion treatment, nitrogen gas bubbles were dispersed into the edible oil in a volume 0.6 times the volume of the edible oil, and in the pressurization treatment, the edible oil in which the bubbles were dispersed was pressurized for an average of about 20 seconds at a pressure 0.15 MPa higher than atmospheric pressure (gauge pressure 0.15 MPa), and then the edible oil that had been subjected to the air bubble dispersion treatment and pressurization treatment was filled.

[0038] In the third embodiment, in the air bubble dispersion process, nitrogen gas bubbles were dispersed in the edible oil by a volume 0.6 times the volume of the edible oil, and in the pressurization process, the edible oil with the dispersed bubbles was pressurized at a pressure 0.03 MPa higher than atmospheric pressure (gauge pressure 0.03 MPa) for an average of about 20 seconds, and then the edible oil that had been subjected to the air bubble dispersion process and the pressurization process was filled. In the fourth embodiment, in the air bubble dispersion process, nitrogen gas bubbles were dispersed in the edible oil by a volume 0.6 times the volume of the edible oil, and in the pressurization process, the edible oil with the dispersed bubbles was pressurized at a pressure 0.01 MPa higher than atmospheric pressure (gauge pressure 0.01 MPa) for an average of about 20 seconds, and then the edible oil that had been subjected to the air bubble dispersion process and the pressurization process was filled.

[0039] In the fifth to seventh examples, the amount of nitrogen gas bubbles dispersed in the bubble dispersion process was changed from that in the first example. In the fifth example, nitrogen gas bubbles were dispersed in the edible oil in an amount one time the volume of the edible oil in the bubble dispersion process, and in the pressurization process, the edible oil in which the bubbles were dispersed was pressurized at a pressure 0.1 MPa higher than atmospheric pressure (gauge pressure 0.1 MPa) for an average of about 20 seconds, and then the edible oil that had been subjected to the bubble dispersion process and the pressurization process was filled.

[0040] In the sixth embodiment, nitrogen gas bubbles were dispersed in the edible oil in an amount of 0.3 times the volume of the edible oil in the air bubble dispersion treatment, and the edible oil in which the bubbles were dispersed was pressurized at a pressure 0.1 MPa higher than atmospheric pressure (gauge pressure 0.1 MPa) in the pressurization treatment, and then the edible oil that had been subjected to the air bubble dispersion treatment and the pressurization treatment was filled. In the seventh embodiment, nitrogen gas bubbles were dispersed in the edible oil in an amount of 0.1 times the volume of the edible oil in the air bubble dispersion treatment, and the edible oil in which the bubbles were dispersed was pressurized at a pressure 0.1 MPa higher than atmospheric pressure (gauge pressure 0.1 MPa) for an average of about 20 seconds in the pressurization treatment, and then the edible oil that had been subjected to the air bubble dispersion treatment and the pressurization treatment was filled.

[0041] (Deterioration test of edible oils and fats) In addition to the above-mentioned Examples, Comparative Examples (Comparative Example 1 to Comparative Example 3) were used to carry out a deterioration test on the edible oils and fats obtained in each Example and Comparative Example. Comparative Example 1 to Comparative Example 3 are examples in which the air bubble dispersion treatment and / or pressure treatment were not carried out in comparison with the above-mentioned First Example. In Comparative Example 1, the edible oils and fats were filled without carrying out the air bubble dispersion treatment and pressure treatment.

[0042] In the second comparative example, only the pressurization treatment was performed without the air bubble dispersion treatment, and then the pressurized edible oil was filled in. In the second comparative example, the edible oil was pressurized at a pressure 0.1 MPa higher than atmospheric pressure (gauge pressure 0.1 MPa) in the pressurization treatment, as in the first example.

[0043] In the third comparative example, the pressurization treatment was not performed, and only the air bubble dispersion treatment was performed, followed by the filling treatment of the edible oil that had been subjected to the air bubble dispersion treatment. In the air bubble dispersion treatment in the third comparative example, nitrogen gas bubbles were dispersed in the edible oil in an amount 0.6 times the volume of the edible oil, as in the first example.

[0044] In the deterioration test, the edible oils and fats obtained in each Example and Comparative Example were evaluated for deterioration two weeks after opening (accelerated test equivalent to 60 days at 20°C) and four weeks after opening (accelerated test equivalent to 120 days at 20°C). Specifically, container C was closed five minutes after opening and stored in this state at 40°C for two or four weeks. The acid value, peroxide value (POV), flavor, and cooked odor of the edible oils and fats two weeks after opening and four weeks after opening were evaluated.

[0045] The acid value of edible oils and fats was evaluated by measuring in accordance with the "Standard Method for Analysis of Fats and Oils 2.3.1-2013 Acid Value" established by the Japan Oil Chemists' Society, and the acid value obtained by the measurement was used as the evaluation value. This acid value correlates with the amount of free fatty acids contained in the edible oils and fats. The smaller the acid value, the less the amount of free fatty acids, which means that the deterioration of the edible oils and fats is suppressed (the increase in acid value is suppressed).

[0046] In the evaluation of the peroxide value of edible oils and fats, the peroxide value was analyzed according to the "Standard Method for Analysis of Fats and Oils 2.5.2.1-2013 Peroxide Value (Acetic Acid-Isooctane Method)" established by the Japan Oil Chemists' Society, and the peroxide value obtained by this analysis was used as the evaluation value. This peroxide value indicates the degree of oxidation of edible oils and fats, and the smaller the peroxide value, the more suppressed the oxidation of the edible oils and fats is.

[0047] In the evaluation of the flavor of edible oils and fats, five expert panelists each held the edible oils and fats in their mouths and evaluated the flavor on a scale of 1.0 to 5.0 points (in increments of 0.1 points) based on the following evaluation criteria, and the average of the evaluation results of the five expert panelists was recorded as the evaluation value. Note that, as shown below, the edible oils and fats before the filling process were used as the reference sample, and the flavor of the reference sample was evaluated as 5.0 points. Flavor evaluation criteria: 5.0 points: The flavor is as good as that of the reference sample (edible oil and fat before filling). 4.0 points: The flavor is slightly inferior to the reference sample, but it is still palatable. 3.0 points: The flavor is inferior to the reference sample, but it is still palatable. 2.0 points: The flavor is significantly inferior to the reference sample and is close to its expiration date. 1.0: The flavor is significantly inferior to the reference sample and cannot be enjoyed.

[0048] In the evaluation of the cooked odor of edible oils and fats, 40g of edible oils and fats were placed in a 100ml beaker and heated to 180℃, after which five expert panelists each smelled the heated edible oils and fats and rated them on a scale of 1.0 to 5.0 (in increments of 0.1) based on the following evaluation criteria to evaluate the cooked odor, with the average of the evaluation results from the five expert panelists being the evaluation value. As shown below, similar to the evaluation of flavor, the edible oils and fats before filling were used as the reference sample, and the cooked odor of the reference sample was rated at 5.0 points. <Evaluation criteria for cooked odor> 5.0 points: The cooked odor is as little as that of the reference sample (edible oil before filling), and there is no odor due to deterioration. 4.0 points: Slightly more cooked odor than the reference sample, but little odor due to deterioration. 3.0 points: There is more of a cooking smell than in the reference sample, but there is little odor due to deterioration. 2.0 points: The smell of cooking was stronger than that of the reference sample, and there was also a lot of smell due to deterioration. 1.0 points: The cooked smell is much stronger than the reference sample, and a strong unpleasant odor is also detected.

[0049] (Test Results) As a result of carrying out a deterioration test on the edible oils and fats obtained in each Example and Comparative Example, the results shown in the table of FIG. 3 were obtained. As shown in FIG. 3, there was no difference in the evaluation of the acid value between the case where the air bubble dispersion treatment and the pressurization treatment were carried out and the case where the air bubble dispersion treatment and / or the pressurization treatment were not carried out, but the evaluation of the peroxide value, flavor, and cooked odor was better in the case where the air bubble dispersion treatment and the pressurization treatment were carried out than in the case where the air bubble dispersion treatment and / or the pressurization treatment were not carried out. From this result, it can be seen that the deterioration of the edible oil and fat in the state after the container C is opened can be suppressed by carrying out the air bubble dispersion treatment and the pressurization treatment. This is presumably because, by carrying out the pressurization treatment on the edible oil and fat in which the air bubbles are dispersed, the air bubbles are likely to remain in the edible oil and fat without being discharged outside the edible oil and fat even after the container C is opened.

[0050] As shown in the test results of the first to seventh examples in Fig. 3, when the gauge pressure of the pressurization treatment was 0.01 MPa or more, the peroxide value was 0.4 or less, and the flavor and cooked odor were 4.8 or more after two weeks from opening, and the peroxide value was 0.5 or less, and the flavor and cooked odor were 4.7 or more after four weeks from opening. In particular, when comparing the third comparative example and the first to fourth examples, which have the same amount of nitrogen dispersion, the higher the gauge pressure of the pressurization treatment, the better the results. When the gauge pressure of the pressurization treatment was 0.03 MPa or more, the peroxide value was 0.2 or less, and the flavor and cooked odor were 5.0 after two weeks from opening, and the peroxide value was 0.3 or less, and the flavor and cooked odor were 5.0 after four weeks from opening, which were better results. These results show that if the pressure in the pressurization treatment is at least 0.01 MPa higher than atmospheric pressure, it is possible to suppress the deterioration of the edible oil after container C is opened, and if the pressure is at least 0.03 MPa higher than atmospheric pressure, it is possible to further suppress the deterioration of the edible oil after container C is opened. Furthermore, the results of a peroxide value of 0.3 or less and a cooked odor rating of 5.0 are almost the same as the ratings for the edible oil before the filling treatment, and mean that no deterioration was observed four weeks after opening.

[0051] As shown in the test results of the first to seventh examples in Fig. 3, when the amount of inert gas dispersed by the air bubble dispersion treatment is 0.05 times or more the volume of the edible oil, the peroxide value is 0.4 or less, the flavor and cooked odor are 4.8 or more after 2 weeks from opening, and the peroxide value is 0.5 or less, and the flavor and cooked odor are 4.7 or more after 4 weeks from opening. In particular, when comparing the second comparative example, the first example, and the fifth to seventh examples, which have the same gauge pressure of the pressurization treatment, the greater the amount of inert gas dispersed, the better the results. When the amount of inert gas dispersed is 0.3 times or more the volume of the edible oil, the better the results are, the peroxide value is 0.2 or less, the flavor and cooked odor are 5.0 or more after 2 weeks from opening, and the peroxide value is 0.3 or less, and the flavor and cooked odor are 5.0 or more after 4 weeks from opening. These results show that if the amount of air bubbles dispersed by the air bubble dispersion treatment is made 0.1 times or more the volume of the edible oil, the deterioration of the edible oil after container C is opened can be further suppressed, and if the amount of air bubbles dispersed by the air bubble dispersion treatment is made 0.3 times or more the volume of the edible oil, the deterioration of the edible oil after container C is opened can be further suppressed.

[0052] (Testing for residual bubbles in edible oils and fats) An air bubble remaining test was conducted on the edible oil obtained in Example 1. In the air bubble remaining test, the air bubble diameter (air bubble particle diameter in oil) (diameter) of the edible oil obtained in Example 1 was measured 5 hours after the air bubble dispersion treatment (air bubble dispersion step) using a nanoparticle size distribution measuring device ("SALD-7500nano" manufactured by Shimadzu Corporation). The measurement of the air bubble diameter of the edible oil in Example 1 was conducted after a blank measurement was conducted on the edible oil in Comparative Example 1.

[0053] (Test Results) The results of the air bubble remaining test are shown in Table 1. From these results, it is presumed that, after going through the dispersion process, the pressurization process, and subsequent storage, air bubbles with a large particle size rise to the top due to their specific gravity, and merge with the head space and disappear. Furthermore, finer air bubbles can be retained in the oil for a longer period of time, and are expected to prevent the nitrogen in the oil from being replaced by air even if the head space is replaced by air when the bottle is opened. [Table 1]

[0054] (Actions and Effects of the Embodiments) As described above, according to the configuration of the above embodiment, by subjecting edible oils and fats to an air bubble dispersion treatment and then further subjecting them to a pressure treatment, it is possible to suppress an increase in the peroxide value, flavor, and cooking odor during storage after container C is opened once, and it is possible to suppress deterioration of the edible oils and fats after container C is opened (unsealed).

[0055] Furthermore, by setting the pressure in the pressurization treatment to a pressure at least 0.03 MPa higher than atmospheric pressure, deterioration of the edible oil or fat after the container C is opened can be further suppressed.

[0056] Furthermore, by setting the pressure in the pressurization treatment to a pressure equal to or lower than atmospheric pressure plus 0.1 MPa, it is possible to prevent the apparatus from becoming complicated.

[0057] In addition, by making the amount of inert gas dispersed by the air bubble dispersion treatment 0.1 times or more the volume of the edible oil or fat, deterioration of the edible oil or fat after container C is opened can be further suppressed.

[0058] Furthermore, by setting the amount of air bubbles dispersed in the air bubble dispersion treatment to 1.2 times or less the volume of the edible oil or fat, defects in the delivery of the edible oil or fat can be prevented.

[0059] Furthermore, by setting the diameter of the bubbles dispersed by the bubble dispersion treatment to 1 μm or less, deterioration of the edible oil or fat after the container C is opened can be further suppressed.

[0060] In addition, if the edible oil or fat after the air bubble dispersion treatment (air bubble dispersion step) contains air bubbles having a diameter of 0.8 μm or less 5 hours after the air bubble dispersion treatment, deterioration of the edible oil or fat after container C is opened can be further suppressed. [Explanation of symbols]

[0061] 1: Edible oil and fat manufacturing device, 11: Storage tank, 12: Air bubble dispersion section, 13: Pressurization section, 14: Filling section, 21: First flow path piping, 22: Second flow path piping, 23: Third flow path piping, 24: Liquid delivery pump, 31: Pressurized tank, 32: Pressure gauge, 41: Filling nozzle, C: Container

Claims

1. A bubble dispersion step of dispersing inert gas bubbles into edible oil and fat; and a pressurizing step of pressurizing the edible oil and fat in which the air bubbles are dispersed.

2. 2. The method for producing edible fats and oils according to claim 1, wherein the pressurizing step is a step of applying a pressure that is 0.01 MPa or more higher than atmospheric pressure.

3. The method for producing edible fats and oils according to claim 2, characterized in that the pressurizing step is a step of applying a pressure that is 0.03 MPa or more and 0.15 MPa or less higher than atmospheric pressure.

4. 2. The method for producing edible fats and oils according to claim 1, wherein the inert gas is one or more gases selected from the group consisting of nitrogen gas, carbon dioxide gas, argon gas, helium and nitrous oxide gas.

5. 2. The method for producing edible oils and fats according to claim 1, wherein the amount of the bubbles of the inert gas dispersed in the bubble dispersion step is 0.05 times or more the volume of the edible oil and fat.

6. The method for producing edible fats and oils according to claim 1 , wherein the air bubbles dispersed in the air bubble dispersion step include air bubbles having a diameter of 1 μm or less.

7. The method for producing edible oil or fat according to claim 6, wherein the edible oil or fat after the air bubble dispersion step contains air bubbles having a diameter of 0.8 μm or less 5 hours after the air bubble dispersion step.

8. A bubble dispersion step of dispersing inert gas bubbles into edible oil and fat; and a pressurizing step of pressurizing the edible oil or fat in which the air bubbles are dispersed.

9. A bubble dispersion unit that disperses inert gas bubbles into edible oil and fat; and a pressurizing section that pressurizes the edible oil and fat in which the air bubbles are dispersed.

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