JP2006254816A - Water-in-oil emulsion oil composition and method for producing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a water-in-oil emulsion oil composition intended for solving such problems that a water-in-oil emulsion oil composition which is not mixed with an additive for food application such as chocolate and margarine, and has long term emulsion stability in mixing with much water content is demanded from increase of health intention of consumers and flavor problem in recent years, but conventionally it is necessary to add a large amount of an emulsifier and a thickener as a food additive when having much water content. <P>SOLUTION: This water-in-oil emulsion oil composition is produced using pressure crystallization technique when crystallizing oil with A units (3)-(6), and homogenizing a mixture obtained through stirring with a pin machine (9). As a result of this, the composition has minute drops and monodispersion, stable in emulsion, free from water separation even if preserved for a long period and sanitarily and physically stable, even if having no additive such as an emulsifier and a thickener for emulsion stability in the mixture or having much water content. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a water-in-oil emulsified oil composition for foods obtained by cooling and kneading an emulsion containing edible oils and fats such as chocolate and margarine, and more particularly, there is no water separation over a long period of time. The present invention relates to a stable water-in-oil emulsified oil and fat composition and a method for producing the same.

  A water-in-oil type emulsified oil / fat composition for foods such as chocolate and margarine is generally produced by blending an emulsifier and undergoing an emulsion formation process, a cooling kneading process, and the like. These foods are in a water-in-oil emulsified form, and it is necessary for the water droplets to be stable for long-term storage. If the emulsification is unstable and the water is separated, not only hygiene problems such as generation of mold occur, but also quality deterioration occurs. However, in recent years, there is a concern about the health effects of additives such as emulsifiers for stabilizing the emulsification due to the consumer's health-oriented needs, and there is a demand for not using emulsifiers or reducing the amount added. Yes. Furthermore, since additives such as emulsifiers have a unique taste and odor, it is desirable not to use them or to reduce them to an amount that does not affect the flavor. In addition, there is an increasing need for products with reduced fats and oils to prevent excessive intake of calories. However, if an additive such as an emulsifier for stabilizing the emulsion is not used or the amount added is reduced, emulsification of the oil and fat composition becomes unstable and water separation occurs, causing problems in terms of hygiene and physical properties as described above. appear. Further, in the case of a water-in-oil type emulsified oil / fat composition, emulsification becomes unstable similarly when the water content is increased, and the same problem as described above occurs.

  In order to solve these problems, a method of devising the type and combination of emulsifiers (Patent Document 1) and a method of adding sugar, fine cellulose, other thickeners, etc. to the aqueous phase are proposed. (Patent Documents 2 and 3) As described above, use of a large amount of an emulsifier and other additives is not preferable. Moreover, although the stabilization method by the addition of diglyceride (Patent Document 4), the addition of high melting point fats and oils (Patent Document 5), the blending of compound oils and fats (Patent Document 6), etc. has been proposed, all are additions such as emulsifiers. Not only is it sufficient for stabilization of high water content oil-in-water emulsified oils and fat compositions with reduced or no added amount of product, but also because it contains oils with a high melting point or a large amount of crystals. It is inevitable that the texture and melting of the mouth worsen. Moreover, although the method of suppressing the coarse crystallization by making oil and fat or the emulsion containing fat and oil ultrafine and atomizing and stabilizing an oil and fat composition (patent document 7), the stabilization of oil and fat is proposed. Although effective, it is not particularly effective for the stability of emulsification. Further, it is disclosed that the stability of pastry margarine is improved by pressure crystallization (Patent Document 8). It is not sufficient for a water-in-oil emulsified oil / fat composition. Thus, the present condition is that the technique which can fully respond to a consumer's needs with respect to the emulsification stability of a water-in-oil emulsified oil-fat composition is not yet established.

JP 2001-178361 A JP-A-7-107906 JP 2000-236810 A Japanese Patent Laid-Open No. 11-243855 JP-A-10-295271 JP 2002-69484 A JP 2003-189793 A JP 2003-134999 A

  The present inventor has disclosed a water-in-oil emulsified oil composition and a method for producing the same, in which emulsification is stable over a long period of time even in the absence of an emulsifier and a thickening stabilizer for stabilizing the emulsion or in a formulation containing a large amount of water. It is something to be offered.

  As a result of intensive studies to solve the above-mentioned problems, the present inventor used a pressure crystallization technique in crystallization of fats and oils in a water-in-oil emulsified fat and oil composition, and by this pressure crystallization, By homogenizing by stirring the mixture of the obtained paste-like fat and water phase and an additive that stabilizes the emulsification, such as an emulsifier and a thickening stabilizer, is not blended in the blend, Even when the amount of water is large, the water droplets are fine and monodisperse, the emulsification is stable, and even when stored for a long period of time, it is found that a product can be obtained that is stable in terms of hygiene and physical properties without water separation. It came to complete.

  That is, the first of the present invention is a water-in-oil emulsified fat composition having a water content of 20 to 70% by weight and containing no additives such as an emulsifier for stabilizing the emulsion, wherein the melted fat and water The present invention relates to a water-in-oil emulsified oil / fat composition characterized by being obtained by homogenizing by stirring a mixture of a pasty oil / fat obtained by pressure crystallization of an emulsion comprising a phase and an aqueous phase. A preferred embodiment is a water-in-oil emulsified fat composition having a water content of 20 to 70% by weight and not containing an additive such as an emulsifier for stabilizing the emulsion, wherein the melted emulsion is subjected to pressure crystallization. A water-in-oil emulsified oil / fat composition obtained by homogenizing a mixture of a pasty oil / fat and an aqueous phase obtained by stirring and having a median diameter of 2 μm or less. More preferably, it is a water-in-oil emulsified fat composition having a water content of 20 to 70% by weight and not containing an additive such as an emulsifier for stabilizing the emulsion, wherein the melted emulsion is subjected to pressure crystallization. The resulting mixture of paste-like oil and fat and the aqueous phase is homogenized by stirring. Water droplets having a diameter of 5 μm or more are 5% or less in terms of the volume fraction of the entire water droplets, and the diameter of the water droplets is the median diameter. It is a water-in-oil type emulsified oil / fat composition characterized by being 2 μm or less.

  In the second aspect of the present invention, a water-in-oil emulsion is prepared by adding 20 to 70% by weight of water to 30 to 80% by weight of edible fats and oils. This is a method for producing a water-in-oil emulsified oil / fat composition obtained by homogenizing and precipitating oil / fat crystals and then homogenizing by stirring. In a preferred embodiment, the pressure applied at the time of cooling and cooling is in the range of 10 to 150 MPa. Further, as a preferred embodiment for homogenization, the mixture is stirred by a pin machine or a static mixer.

  A water-in-oil emulsion is prepared by adding 20 to 70% by weight of water to 30 to 80% by weight of edible fats and oils. By using the pressure crystallization technique of precipitating and homogenizing the crystals, even if additives such as emulsifiers and thickening stabilizers are not blended in the blending, In addition, a water-in-oil emulsified oil and fat composition that is stable even if the amount of water is high, is stable even after long-term storage, and does not separate water and is stable in terms of hygiene and physical properties.

  The fats and oils used in the water-in-oil emulsified fat and oil composition of the present invention are not particularly limited, and any fats and oils that are conventionally used for margarine and shortening can be used. For example, corn oil, linseed oil, Paulownia oil, safflower oil, pod oil, sesame oil, coconut oil, cottonseed oil, sunflower oil, rapeseed oil, soybean oil, pepper oil, kapok oil, rice bran oil, walnut oil, falling raw oil, olive oil, coconut oil, tea oil, castor oil, Eggplant oil, palm oil, palm kernel oil, khair oil, coconut oil, cocoa butter, shea butter, coconut butter, borneo and other vegetable oils, fish oil, whale oil, beef tallow, pork tallow, chicken oil, egg yolk oil, sheep oil, etc. 1 or 2 or more types of fats and oils selected from these animal oils are used, and all types of fats and oils that are normally used for food use such as those obtained by transesterification, hardening and fractionation of these fats and oils are used. I can do it.

  In order to produce the water-in-oil emulsified oil / fat composition according to the present invention, first, 20-70% by weight of water is added to 30-80% by weight of the oil / fat heated to the melting point or higher to obtain a water-in-oil emulsion. create. Cooling and kneading treatment is performed while pressurizing the water-in-oil emulsion in a state where the fats and oils are melted. Thereby, first, fine and stable crystal nuclei are precipitated. Water droplets in the water-in-oil emulsion are stabilized by the fine crystals, and a water-in-oil emulsified oil / fat composition comprising a mixture of a paste-like oil / fat and an aqueous phase is obtained. Furthermore, by homogenizing the mixture by stirring, the water droplets in the composition are fine and monodispersed, and a more stable water-in-oil emulsified fat composition is obtained. The water-in-oil type emulsified oil / fat composition thus obtained has a water droplet diameter of 2 μm or less in terms of median diameter, and a large water droplet having a diameter of 5 μm or more has a volume fraction of 5% or less of the entire water droplet. It becomes an emulsified state close to monodispersion. Thus, a stable water-in-oil emulsified oil / fat composition without water separation even when stored for a long period of time is obtained. The median diameter and the large water droplets having a diameter of 5 μm or more are not particularly limited in the method for measuring the volume fraction of the entire water droplets, and can be easily measured by a known image processing apparatus. In addition, commercially available image processing software can be used. Even if it uses, it can measure easily.

  In the above case, when the water content exceeds 70% by weight, the water droplets coalesce, the volume fraction of the water droplets having a diameter of 5 μm or more becomes 5% or more of the whole, and water separation occurs. Further, if the water content is less than 20% by weight, water separation can be carried out by the described method without using the method of the present invention, for example, a method of blending a high melting point oil (Patent Document 5) or a method using only pressure crystallization. A stable water-in-oil emulsified oil / fat composition free from water can be obtained.

  The pressurization at the time of cooling kneading in the pressure crystallization is usually performed in the range of 10 to 150 MPa. When the pressure is less than 10 MPa, the precipitation of crystal nuclei does not occur sufficiently, so that a stable water-in-oil emulsified oil / fat composition cannot be obtained. In addition, the treatment may be performed at a high pressure exceeding 150 MPa, but the effect of promoting the precipitation of crystal nuclei is reduced, and the pressurization at a pressure higher than necessary is economically and from the viewpoint of the safety of the apparatus. Is also not preferred. The pressurization may be performed simultaneously with the cooling, or may be performed after the cooling is performed to such an extent that crystals are not precipitated in advance. The pressurization may be continued until the crystallization is completely completed, but the water-in-oil emulsified oil / fat composition of the present invention can be obtained only during the initial precipitation of crystal nuclei. The pressure crystallization treatment may be any method, such as a batch method or a continuous method.

  The pressure crystallization method is not particularly limited, and specifically, the emulsified oil / fat composition is heated and dissolved, and injected into a hydrostatic pressure vessel, for example, and pressurized and cooled. The pressurization method may be any of a piston type, a hydraulic type, and a pneumatic type. The cooling method may be either a refrigerant method or an air cooling method. Pressurization pressure, pressurization time, and cooling medium temperature cannot be defined unconditionally because the optimum values differ depending on the raw material composition and amount of the edible oil and fat used, but the pressurization pressure is preferably 10 to 150 MPa as described above, 20-70 MPa is preferable. The pressing time is preferably 1 to 60 minutes, and more preferably 2 to 10 minutes. The pressurization time is determined in consideration of the pressurization pressure, temperature, oil composition, etc., but if it is less than 1 minute, the precipitation of crystal nuclei may be insufficient. The pressure treatment may be performed until crystal nuclei are generated, but there is no problem if the pressure treatment is continued until further crystals are precipitated. It is preferable to perform the treatment at a temperature of the cooling medium in the range of -30 to 15 ° C. When the temperature of the cooling medium is higher than 15 ° C., the cooling rate is slow and the crystallization time is long. On the other hand, when the temperature of the cooling medium is lower than −30 ° C., the cooling rate is increased, but the improvement of the crystal nucleation promotion effect by pressurization is reduced, which is not preferable from the economical viewpoint.

  The emulsified oil / fat composition in which fine and stable crystal nuclei are precipitated by the pressure crystallization treatment and the water droplets are stabilized is in a state in which the paste-like oil / fat and the aqueous phase are mixed. Furthermore, when this is stirred and homogenized, the water droplets become fine and monodispersed, and a more stable water-in-oil emulsified fat composition is obtained. The homogenization treatment in this case may be a simple stirring device as long as it is a batch type, but in the case of continuous processing or the like, it is preferable to use a stirring device such as a pin machine, an in-line mixer such as a static mixer, or the like. In this case, although the melting of the crystals occurs due to the temperature rise, the stable water-in-oil emulsified oil / fat composition of the present invention can be obtained unless the fats and oils are completely melted, that is, unless the initially precipitated crystal nuclei are melted. The temperature at which the initially precipitated crystal nuclei do not melt varies depending on the fats and oils used, but the crystal nuclei remain unless the temperature first exceeds the temperature at which the crystal nuclei precipitate, leaving the target stable water-in-oil emulsified fat composition. Can be obtained. The stirring device that can be used for the homogenization treatment is not limited to the pin machine or the static mixer, and various kneaders, extruders, nanomizers, and the like may be used alone or in combination. Absent.

  Since the water-in-oil type emulsified oil / fat composition of the present invention is stabilized by fine oil / fat crystal nuclei deposited by pressure crystallization, an emulsifier used for normal edible oil / fat and additives for stabilization, etc. Although it is not necessary to add, as long as it does not inhibit the intended effect of the present invention, for example, glycerin fatty acid ester, sorbitan fatty acid ester, lecithin, polyglycerin fatty acid ester, propylene glycol fatty acid ester, An emulsifier such as a sugar fatty acid ester may be used. Moreover, dairy products, salt, a fragrance | flavor, a coloring agent, antioxidant, etc. can be added to the water-in-oil type emulsified oil-fat composition of this invention as needed.

  The water-in-oil emulsified oil / fat composition of the present invention obtained as described above shows separation of water droplets even at high water content without adding an additive for emulsification stabilization such as an emulsifier. Therefore, it is an excellent water-in-oil emulsified oil and fat composition that can be stored stably for a long period of time and is unprecedented in terms of hygiene and properties.

  Hereinafter, although this invention is demonstrated based on an Example and a comparative example, this invention does not receive any limitation by these. In the following description, unless otherwise specified, “part” and “%” all represent “part by weight” and “% by weight”.

An oil phase of 30% hardened corn oil (melting point 40 ° C.), refined lard (melting point 31 ° C.) 30%, and rapeseed oil 40% was prepared. To 80 parts of this oil phase, 20 parts of water was added to about 60 ° C. The temperature was adjusted, and the mixture was stirred and mixed with a propeller mixer. Thereafter, an emulsification tank (1), a piston pump (2), three cooling kneaders [A1 unit (3), A2 unit (5) and A3 unit (6)] and a pin machine [B shown in FIG. Unit (9)], the pressure in the A2 unit (5) and A3 unit (6) is controlled to 50 MPa by the gear pumps (4) and (7), and the product temperature (margarine at the outlet of the A3 unit (6) is controlled. The water-in-oil type emulsified oil / fat composition was manufactured under the conditions of a temperature of 10 ° C. and a flow rate of 100 kg / h. The A units of A1 to A3 are cylindrical jacketed (coolable) heat exchange units with an inner diameter of 150 mm and a length of about 300 mm, and are cylindrical by rotating a shaft with scraping teeth inserted inside. This is a scraping-type heat exchange device that mixes and stirs while scraping the crystals on the inner surface. In this embodiment, the shaft has a diameter of 130 mm, and the clearance between the shaft and the inner surface of the cylinder, called clearance, is 10 mm. Used approximately 1320 cc. When the flow rate is 100 kg / h, the residence time per cylinder (A unit) is about 45 seconds. Further, the B unit (pin machine) is a kneading apparatus having a size similar to that of the A unit, having no scraping teeth on the shaft, and provided with a large number of rod-like projections called pins. Is several times larger than the A unit. As these A unit and B unit, those having a known structure can be used. In the figure, reference numeral 8 denotes a pipe.
The water-in-oil emulsified oil / fat composition obtained as described above did not have water separation and exhibited the same shape as that of ordinary margarine.

  An oil phase of 30% hardened corn oil (melting point 40 ° C.), refined lard (melting point 31 ° C.) 30%, and rapeseed oil 40% is prepared. To 50 parts of this oil phase, 50 parts of water is added to about 60 ° C. The temperature was adjusted, and the mixture was stirred and mixed with a propeller mixer. Then, using the system similar to Example 1, the water-in-oil type emulsified fat composition was manufactured by the same method and conditions. The obtained water-in-oil type emulsified oil / fat composition showed the same shape as normal margarine without water separation.

  An oil phase of 30% hardened corn oil (melting point 40 ° C.), refined lard (melting point 31 ° C.) 30%, and rapeseed oil 40% was prepared, and 70 parts of water was added to 30 parts of this oil phase to about 60 ° C. The temperature was adjusted, and the mixture was stirred and mixed with a propeller mixer. Then, using the system similar to Example 1, the water-in-oil type emulsified fat composition was manufactured by the same method and conditions. The obtained water-in-oil type emulsified oil / fat composition showed the same shape as normal margarine without water separation.

  An oil phase of 30% hardened corn oil (melting point 40 ° C.), refined lard (melting point 31 ° C.) 30%, and rapeseed oil 40% was prepared, and 70 parts of water was added to 30 parts of this oil phase to about 60 ° C. The temperature was adjusted, and the mixture was stirred and mixed with a propeller mixer. Thereafter, the emulsification tank (1), piston pump (2), three cooling kneaders [A1 unit (3), A2 unit (5) and A3 unit (6)] and static mixer (as shown in FIG. 2) 9), the pressure in the A2 unit (5) and the A3 unit (6) was controlled to 50 MPa by the gear pumps 4 and 7 to produce a water-in-oil type emulsified oil / fat composition. The obtained water-in-oil type emulsified oil / fat composition showed the same shape as normal margarine without water separation.

(Comparative Example 1)
An oil phase of 30% hardened corn oil (melting point 40 ° C.), refined lard (melting point 31 ° C.) 30%, and rapeseed oil 40% was prepared. To 80 parts of this oil phase, 20 parts of water was added to about 60 ° C. The temperature was adjusted, and the mixture was stirred and mixed with a propeller mixer. Thereafter, in a system comprising an emulsification tank (1), a piston pump (2), and three cooling kneaders [A1 unit (3), A2 unit (5) and A3 unit (6)] as shown in FIG. The pressure in the A2 unit (5) and the A3 unit (6) was controlled to 50 MPa by the gear pumps (4) and (7) to produce a water-in-oil emulsified oil / fat composition. The obtained water-in-oil emulsified oil / fat composition was water-separated, and compared with ordinary margarine, the texture was rough and the physical properties were deteriorated.

(Comparative Example 2)
An oil phase of 30% hardened corn oil (melting point 40 ° C.), refined lard (melting point 31 ° C.) 30% and rapeseed oil 40% is prepared, and 20 parts of water is added to this oil phase, and the temperature is raised to about 60 ° C. The mixture was stirred and mixed with a propeller mixer. Thereafter, the emulsification tank (1), piston pump (2), three cooling kneaders [A1 unit (3), A2 unit (5) and A3 unit (6)] and pin machine [B shown in FIG. In a system including the unit (9)], the pressure in the A2 unit (5) and the A3 unit (6) was not controlled by the gear pumps 4 and 7, and a water-in-oil emulsified fat composition was produced at a pressure of less than 10 MPa. The obtained water-in-oil emulsified oil / fat composition was water-separated, and compared with ordinary margarine, the texture was rough and the physical properties were deteriorated.

  An oil phase of 30% hardened corn oil (melting point 40 ° C.), refined lard (melting point 31 ° C.) 30%, and rapeseed oil 40% was prepared. To 80 parts of this oil phase, 20 parts of water was added to about 60 ° C. The temperature was adjusted, and the mixture was stirred and mixed with a propeller mixer. Thereafter, the emulsification tank (1), piston pump (2), three cooling kneaders (A1 unit (3), A2 unit (5) and A3 unit 6) and pin machine (B unit) as shown in FIG. 9, the pressure in the A2 unit (5) and the A3 unit (6) was controlled to 10 MPa by the gear pumps (4) and (7) to produce a water-in-oil emulsified oil / fat composition. The obtained water-in-oil type emulsified oil / fat composition showed the same shape as normal margarine without water separation.

  An oil phase of 30% hardened corn oil (melting point 40 ° C.), refined lard (melting point 31 ° C.) 30%, and rapeseed oil 40% was prepared, and 70 parts of water was added to 30 parts of this oil phase to about 60 ° C. The temperature was adjusted, and the mixture was stirred and mixed with a propeller mixer. Thereafter, the emulsification tank (1), piston pump (2), three cooling kneaders [A1 unit (3), A2 unit (5) and A3 unit (6)] and pin machine [B shown in FIG. In a system including the unit (9)], the pressure in the A2 unit (5) and the A3 unit (6) was controlled to 10 MPa by the gear pumps (4) and (7) to produce a water-in-oil type emulsified fat composition. Although the obtained water-in-oil emulsified oil / fat composition showed slight water separation, it showed the same shape as normal margarine.

  All the water-in-oil emulsified oil / fat compositions of Examples and Comparative Examples obtained as described above were all stored in a refrigerator (about 5 ° C.). The following evaluation was performed after 1 day and 1 month.

(Evaluation of margarine status)
The obtained water-in-oil emulsified oil / fat composition was temperature-controlled at 20 ° C., and spread on an aluminum foil with a confectionery knife (pallet knife) (nappe), and the presence or absence of water separation was evaluated. The results are shown in Table 1.

Evaluation points:
"Surface condition"
5: Smooth and fine
4: Almost smooth and fine
3: There is some unevenness
2: Unevenness is noticeable and rough
1: There is unevenness throughout and the texture is very rough.
A: No water separation
○: The surface shines slightly, but no water droplets are seen
Δ: Water drops are seen in some places
×: Water droplets are seen on the front

(Measurement of water droplet size)
The obtained water-in-oil emulsified oil / fat composition was observed with an optical microscope, and the obtained image was analyzed with an image analyzer (manufactured by Nireco Corporation, Luzex IIIU). The average particle diameter (median diameter) of water droplets and The volume fraction of water droplets of 5 microns or more was calculated. The results are shown in Table 2.

  As is clear from Tables 1 and 2, the water-in-oil emulsion in which the fats and oils are melted is subjected to pressure crystallization, followed by stirring and homogenization, so that no emulsifier or thickening stabilizer for stabilizing the emulsion is added. In addition, a water-in-oil emulsified oil / fat composition that is stable for a long period of time can be obtained even in a formulation having a large amount of water.

It is process explanatory drawing which shows the manufacturing process of Examples 1, 2, 3, 5 and the water-in-oil type emulsified oil-fat composition of the comparative example 2. It is process explanatory drawing which shows the manufacturing process of the water-in-oil type emulsified fat composition of Example 4. It is process explanatory drawing which shows the manufacturing process of the water-in-oil type emulsified fat composition of the comparative example 1.

Explanation of symbols

1 Emulsifying tank 2 Piston pump 3 Cooling kneader (A1 unit)
4 Gear pump 5 Cooling kneader (A2 unit)
6 Cooling kneader (A3 unit)
7 Gear pump 8 Piping 9 Homogenization equipment (pin machine, static mixer)

Claims (7)

  A water-in-oil emulsified fat composition having a water content of 20 to 70% by weight and containing no additives such as an emulsifier for stabilizing the emulsion, and pressurizing an emulsion comprising a melted fat and oil and an aqueous phase. A water-in-oil type emulsified oil / fat composition obtained by homogenizing a mixture of a paste-like oil / fat obtained by analysis and an aqueous phase by stirring.   The water-in-oil emulsified oil / fat composition according to claim 1, wherein the water droplet has a median diameter of 2 μm or less.   The water-in-oil emulsified oil / fat composition according to claim 1 or 2, wherein a water droplet having a diameter of 5 µm or more is 5% or less in terms of a volume fraction of the entire water droplet.   A water-in-oil emulsion is prepared by adding 20 to 70% by weight of water to 30 to 80% by weight of edible fats and oils. A method for producing a water-in-oil type emulsified oil / fat composition, which is homogenized by stirring after precipitation.   The method for producing a water-in-oil emulsified oil / fat composition according to claim 4, wherein the pressure applied during cooling is 10 to 150 MPa.   The manufacturing method of the water-in-oil type emulsified oil-fat composition of Claim 4 or 5 which stirs a mixture with a pin machine. The method for producing a water-in-oil emulsified oil / fat composition according to claim 4 or 5, wherein the mixture is stirred by a static mixer.

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