JPH0757160B2 - Method for producing oil-in-water emulsion - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for producing an oil-in-water emulsion and an apparatus therefor, and the oil-in-water emulsion obtained by the production method of the present invention has a long-term storage stability. It has excellent properties, is suitable for distribution, and has a good flavor, and can be widely used as, for example, confectionery, bread fillings, topping materials, coffee creams or cooking ingredients.

[Problems to be Solved by Prior Art and Invention]

As the oil-in-water emulsion, there are whipped cream, coffee cream, soup, custard cream and flower pastes and sauces for prepared foods, and the like. , Such as retort pouches, which are sterilized under pressure and heat after being packed in a container, and continuous sterilization methods such as continuous sterilization by an indirect heating method such as using a scraping heat exchanger have been performed. .

However, in the continuous sterilization treatment method by the indirect heating method, it takes a long time to heat-treat the oil-in-water emulsion to raise the temperature to the sterilization temperature and sterilize it, and then cool it from the sterilization temperature. It has a large heat history and is unsatisfactory in the flavor, color tone, nutritional value, texture and the like of the product, and also has a problem that the electric heating surface of the scraping-type heat exchanger is apt to cause sticking.

Therefore, as a heat sterilization method having a small heat history, a method using an ultra-high temperature instantaneous sterilizer by a direct heating method has been attempted (Japanese Patent Laid-Open No. 63-44841). However, in the above direct heating method, since high temperature steam is directly mixed with the product, the steam injection part and the jacket part for mixing the steam and the product become too hot, and therefore, the oil-in-water type containing the protein material is used. In the case of an emulsion, there is a problem that kogation occurs and the kogation is mixed into the product. In this way, if kogation is mixed in the product, it may be mistaken for mold, etc., or it may cause a complaint because it looks bad.Therefore, in order to solve the above-mentioned problems, the amount of protein material added should be reduced or the heating temperature should be reduced. I have dealt with it by lowering it.

However, if the heating temperature is lowered, the storability is deteriorated, which may cause a problem recently, and if the amount of the protein is reduced, another problem such as bad taste is caused.

On the other hand, in response to the recent trend toward higher quality and diversification of food products, it is possible to more rationally produce an oil-in-water emulsion having excellent long-term storage stability, suitable for distribution, excellent workability, and good taste. Has been requested.

Therefore, the object of the present invention is to eliminate the disadvantage that the above-mentioned kogation occurs, and moreover, it is excellent in storability and workability,
An object of the present invention is to provide a method for producing an oil-in-water emulsion suitable for distribution, having a good flavor and having a wide range of use, and an apparatus therefor.

[Means for Solving the Problems]

As a result of earnest research for solving the above problems, the present inventors have found that the above objects can be achieved by using a specific means.

The present invention has been made based on steam knowledge, and includes the following I to II.
The present invention provides a method for producing an oil-in-water emulsion comprising the process I.

I. Emulsification process for preparing an oil-in-water emulsion containing 1 to 70% by weight of edible oil and fat, 0.2 to 10% by weight of protein material (as protein mass) and water, and II. Mixing section equipped with steam injection means And using a device having a high-temperature steam injection part provided with a cooling means for cooling the wall part constituting the mixing part, while cooling at least a part of the wall part, Direct heat treatment step of mixing the introduced oil-in-water emulsion with high temperature steam and maintaining the temperature of the oil-in-water emulsion at 100 to 160 ° C. for 1 to 30 seconds, and III. An evaporative cooling step of cooling the oil-in-water emulsion by evaporating water in the oil-based emulsion under reduced pressure.

[Action]

The present invention also provides the following device as a device for carrying out the above-mentioned manufacturing method. The following apparatus is not limited to the oil-in-water type emulsion to which the fluid to be heated is applied, but can be applied to other fluids.

A mixing portion is provided which allows the heated fluid to be circulated and allows the steam to be directly mixed with the heated fluid, and a part of the wall surface of the mixing portion is formed of a porous member having a large number of steam injection pores. In the ultra-high temperature sterilizer that is used,
An ultra-high temperature sterilizer, wherein a cooling mechanism for circulating a cooling liquid is attached to at least a part of the outside of the wall surface other than the wall surface in the mixing section.

In the present invention, when heat-sterilization is performed by mixing high-temperature steam with an oil-in-water emulsion, by cooling at least a part of the wall portion forming the mixing portion, kogation due to heating occurs in the oil-in-water emulsion. It is to prevent that.

Hereinafter, the method for producing the oil-in-water emulsion of the present invention will be described in detail.

Examples of edible oils and fats used in the present invention include natural animal and vegetable oils and fats, processed oils and fats subjected to transesterification, hydrogenation, fractionation, etc., butter, margarine, shortening and the like, and these are used alone or in a mixture. This is used.

The amount of the above-mentioned edible oil / fat added is 1 to 70% by weight, preferably 2 to 45% by weight, as an oil content. If it is less than 1% by weight, the texture will be unsatisfactory, and if it is 70% by weight or more, it will be impossible to obtain an oil-in-water emulsion.

In addition, an antioxidant, an oil-soluble pigment or the like can be added to the edible oil / fat (oil phase), if necessary.

Further, in the present invention, a protein material is used as an essential component. When the edible oil and fat and an aqueous phase containing water and other optional water-soluble and water-dispersible auxiliary materials (described later) are emulsified into an oil-in-water type, the surfactant action of the protein material is exerted. Although it can be used, an emulsifier can be further added, if desired, when the surface activity is insufficient.

The protein material used in the present invention includes a water-soluble simple protein (albumin category) having a surface-active effect,
Edible materials containing complex proteins (glycoprotein, phosphoprotein, nucleoprotein, chromoprotein, etc.) and hydrolyzed protein, specifically, animal milk, casein, sodium caseinate, skim milk powder, whey powder, egg yolk, Examples thereof include egg white and its powder, soybean protein, those obtained by enzymatically or chemically decomposing them and extracting with water, and various amino acids and peptides. These may be used alone or in combination of two or more kinds. good.

In the present invention, in order to emulsify the edible oil / fat and the aqueous phase into the oil-in-water type, only the protein material may be used as described above, or an emulsifier may be used in combination. The protein material and the emulsifier may be used in an amount sufficient to stably emulsify the edible oil and fat and the aqueous phase into an oil-in-water type.

Usually, when only a protein material is used, the protein amount is preferably 0.2 to 10% by weight.

If the amount of the protein material as a protein amount is 0.2% by weight or less, the taste becomes unpleasant, and if it is 10% by weight or more, coagulation occurs due to denaturation of the protein and heat treatment by direct heating becomes impossible.

When both of the above are used in combination, the emulsifier is preferably 0.05 to 4% by weight with respect to the amount of protein material used of 0.2 to 10% by weight.

Further, in the present invention, the emulsifier optionally used in the present invention may be an additive to foods, for example, glycerin fatty acid ester, sorbitan fatty acid ester, sucrose fatty acid ester, propylene glycol fatty acid ester, phospholipids, and the like, these Can be used alone or 2
You may use together more than one kind. When using these emulsifiers, the oil-soluble emulsifier is preferably dissolved in the edible oil and fat (oil phase), and the water-soluble emulsifier is preferably dissolved in the water phase.

The oil-in-water emulsion of the present invention, within the scope of the object of the present invention, optionally further auxiliary materials, glucose, fructose,
Sucrose, maltose starch syrup, sugar alcohol, water-soluble sugars such as dextrin, salt, potassium chloride, sodium citrate, phosphate, salts such as glutamate sodium, gelatin, high methoxyl pectin, pectins such as low methoxyl pectin, Locust bean gum, xanthan gum,
Carrageenan, furceleran, agar and tamarind seeds, pastes such as carboxymethyl cellulose, lactic acid, acids such as citric acid, crystalline cellulose, peanut powder, peanut paste, cacao powder, cheese powder, sesame seeds, raw bean paste, bean paste , Starch such as rice flour, wheat flour, corn flour, potatoes, rice, corn, waxy corn, sweet potato, wheat, tapioca, red beans, kidney beans, cowpeas, broad beans, and beans, and starch derived from these Roasted dextrin, enzyme-modified starch, ester starch,
Modified starches such as oxidized starch, etherified starch, cross-linked starch,
Animal milk, fruit juice, processed fruits, vegetables, extracts, seasonings,
Water-soluble substances such as spices, spices, coloring agents, water-dispersible substances,
An oil-soluble substance and an oil-dispersible substance can be appropriately combined and used.

When these auxiliary raw materials contain fats and oils and protein raw materials, the amounts of edible fats and oils and protein raw materials in the oil-in-water emulsion containing them must be the amounts specified above.

In carrying out the present invention, first, an oil-in-water emulsion containing 1 to 70% by weight of edible oil and fat, 0.2 to 10% by weight of protein material, and water as essential components is emulsified and prepared.

The emulsification step in the present invention, before performing the direct heat treatment,
When using an oil phase (consisting of an edible oil and fat, an oil-soluble emulsifier when using an emulsifier, and an optional oil-soluble, oil-dispersible auxiliary material) and an aqueous phase (starch, water-soluble emulsifier) in the storage tank Is composed of this emulsifier and protein material, and optionally water-soluble and water-dispersible auxiliary materials,
The mixture may be mixed with stirring to be pre-emulsified into an oil-in-water type, but if necessary, before direct heat treatment, and if necessary after direct heat treatment, an emulsifying machine such as a homomixer, homogenizer, colloid mill or the like. May be used for homogeneous emulsification.

Further, before the direct heat treatment, the oil-in-water emulsion may be preheated by a heat exchanger or the like.

Then, the oil-in-water emulsion obtained as described above is directly heat-treated.

The direct heat treatment step in the present invention involves mixing the above-mentioned oil-in-water emulsion and high-temperature steam, at which time the oil-in-water emulsion is sufficiently heated, and a temperature and a holding time sufficient for sterilization are required. The heat treatment is usually performed at 100 to 160 ° C. for 1 to 30 seconds, preferably 135 to 150 ° C. for 2 to 10 seconds. When the heating temperature and the heating time are each lower than the above lower limit, there is a problem that bacteria remain, and conversely, when the heating temperature and the heating time are higher than the above upper limit, kogation easily occurs.

In the present invention, when performing the above heat treatment, the high temperature injection section has a mixing section provided with a steam injection section, and a cooling section is attached to at least a part of an outer side of a wall forming the mixing section. A device equipped with is used. In the mixing section, an oil-in-water emulsion that is a fluid to be heated is introduced, high temperature steam is injected while passing through the mixing section, and the emulsion and the injected high temperature steam are mixed, The oil-in-water emulsion is heated to the predetermined temperature for a predetermined time.

The means for cooling the wall portion in the mixing portion is not particularly limited, but it is preferable to attach a cooling mechanism for circulating the cooling liquid to the wall portion and the outside thereof. A liquid having a high specific heat may be used as the cooling liquid, and water is particularly preferable.

The degree of cooling may be such that no kogation occurs and the heating temperature can be maintained for a predetermined time. Specifically, it is affected by the heating temperature, the specific heat of the emulsion, the thickness of the jacket (wall), etc., but for example, when using a device having a heat treatment capacity of 2 t / h, per second 200c
Cooling may be performed to the extent that al-2000 cal of heat can be removed from the emulsion.

Then, after heating, the oil-in-water emulsion is subjected to a reduced pressure treatment and cooled by evaporating the contained water.

The degree of cooling in the evaporative cooling step is set to be 1 temperature higher than the temperature of the oil-in-water emulsion before the high temperature steam injection for the purpose of making the water content contained in the oil-in-water emulsion substantially the same before and after the heat treatment. It is preferable to cool to a temperature higher by ˜2 ° C., but after cooling, it may be further cooled by a heat exchanger or the like.

In addition, as for the apparatus for performing the above-mentioned direct heat treatment,
Any device can be used without particular limitation as long as it is a device provided with a means capable of reliably mixing high temperature steam with the emulsion in a short time and a means for cooling at least a part of the wall portion constituting the mixing portion. is there. Therefore, various commercially available direct heating type heating devices can be used, and the device can be provided by using a device provided with a cooling means.

Commercially available heating devices that can be effectively used include, for example, an operator sterilizer (Alpra Co., Ltd.), an Alfa Laval VTIS sterilizer (Alfa Laval Co.), a Lagia sterilizer (Lagia Co.), and a paralyzer (Pash &・ Silkeborg), CPVac.Heat VHT sterilizer (Crimally Package), KID's Cooker (Kikkoman Corp.), Noritake Cooking Device (Noritake Company Limited), Jet Cooker Device (Alfa Laval) Manufactured by Kureha Engineering Co., Ltd.)

Furthermore, this direct heat treatment has a porous member (steam injection means) having a large number of high-temperature steam injection pores as at least one surface, and a wall portion (constituting a mixing portion) formed facing the porous member. While moving the oil-in-water emulsion at a flow rate of 0.05 to 1.5 m / sec in the thin layer space formed between the oil-in-water emulsion and the pores of the porous member described above. It is preferable to carry out by injecting high temperature steam, and as a device having a high temperature steam injecting section of such a mechanism and having a mixing section capable of directly performing heat treatment, the above-mentioned Kureha type ultra-high temperature instantaneous sterilization is used. A device (manufactured by Kureha Engineering Co., Ltd.) is suitable.

The details of the structure of the high temperature steam injection part of the Kureha type ultra-high temperature instantaneous sterilizer are described in JP-A-58-205481, but the high temperature steam injection part of the device suitable for carrying out the present invention is Further, a structure having a cooling water flow passage (cooling means) provided outside the wall portion forming the mixing portion through which the emulsion fluid passes is preferable, and the outline thereof is shown.
It is a figure and FIG.

That is, FIG. 1 shows a main part of an ultra-high temperature instantaneous sterilization apparatus used for carrying out the present invention, and a cross-sectional view of the high-temperature steam injection section as seen from the side in the moving direction of the oil-in-water emulsion. ,
FIG. 2 is a sectional view taken along the line AA of FIG. In the figure, 1 is a porous member (perforated plate) having a large number of high-temperature steam injection pores 1a, 2 is a wall constituting a mixing portion, 3 is a thin layer space formed by the porous plate 1 and the wall 2. (Mixing part), 4
Is a high temperature steam inlet, 5 is an oil-in-water emulsion inlet, is an oil-in-water emulsion outlet, 7 is a cooling water inlet, 8 is a cooling water outlet, and 9 is on the outside of the wall portion 2 constituting the mixing portion. This is an attached cooling water passage (cooling means).

The thickness of the thin layer space 3 is 1 to 15 mm, preferably 2 to 10 mm.
mm is good, and the diameter of the high temperature steam injection pores 1a is
0.1-4 mm, preferably 0.4-2 mm. Further, the cooling water passage is not limited to being attached to the entire wall portion as shown in the figure, but a part thereof may be attached.

Further, FIG. 3 is a flow sheet showing an example of the steps of the direct heat treatment in the present invention, where I is an oil-in-water emulsion supply tank, II is a supply pump, III is a high temperature steam injection section, and IV.
Is a high temperature holding unit, V is a vacuum dewatering / cooling unit, VI is a product tank, VII is a dewatered condenser of water, and VIII is a vacuum pump.

〔Example〕

Hereinafter, the present invention will be described in more detail with reference to Examples of the present invention together with Comparative Examples, but the following Examples do not limit the present invention in any way.

The state of the mixture of kogation in the emulsion, which is a product, was summarized for each predetermined time, and the results are shown in Table 1 below.

Example 1 First, 15 parts by weight of white sucrose, 5 parts by weight of corn starch, 3 parts by weight of soft flour, 4 parts by weight of skim milk powder, 10 parts by weight of egg yolk, 0.2 parts by weight of gelatin, 0.2 parts by weight of custard flavor, 0.1 part by weight of sodium tripolyphosphate and 47 parts by weight of water were mixed to prepare an aqueous phase.

Then, while heating the aqueous phase to 50 ° C, a solution of 0.5 parts by weight of sorbitan fatty acid ester dissolved in 20 parts by weight of edible soybean oil heated to 50 ° C was added little by little to emulsify into an oil-in-water type, Homogenization pressure 10 with a high-pressure homogenizer
The homogenization treatment was performed under 0 kg / cm ² .

Next, while maintaining this oil-in-water emulsion at 50 ° C, a Kureha-type ultra-high temperature instant sterilizer (Kureha Engineering Co., Ltd.)
(Manufacturing; processing capacity: 2 t / h), using an apparatus provided with a cooling mechanism as shown in FIGS. 1 and 2, the temperature of the emulsion was kept at 135 ° C. for 10 seconds and then cooled to 52 ° C. by evaporation under reduced pressure. . During the heat treatment, cooling water (20 ° C.) was caused to flow in the cooling water passage 7 to cool the wall portion forming the mixing portion (removal heat amount 800 cal / sec).
The state of kogation in this oil-in-water emulsion was as shown in Table 1 below, and the flavor was also good.

Example 2 First, 15 parts by weight of skim milk powder, 20 parts by weight of milk, 5 parts by weight of lactose, 0.2 parts by weight of sodium hexametaphosphate, 0.5 parts by weight of milk flavor, and 49 parts by weight of water were mixed to prepare an aqueous phase.

Then, while heating the water holes to 50 ° C, little by little 0.3 parts by weight of monoglyceride dissolved in 10 parts by weight of corn oil heated to 50 ° C was added little by little, and emulsified into an oil-in-water type,
Further, homogenization treatment was performed with a high-pressure homogenizer under a homogenization pressure of 100 kg / cm ² .

Next, while maintaining this oil-in-water emulsion at 50 ° C, a Kureha-type ultra-high temperature instant sterilizer (Kureha Engineering Co., Ltd.)
(Manufacturing capacity: processing capacity 2 t / h), a cooling mechanism as shown in FIGS. 1 and 2 was provided, and the temperature of the emulsion was held at 150 ° C. for 3 seconds, and then cooled to 52 ° C. by evaporation under reduced pressure. During the heat treatment, cooling water (20 ° C.) was caused to flow through the cooling water passage 9 to cool the wall portion forming the mixing portion (removal heat amount 800 cal / sec). The state of kogation of this oil-in-water emulsion was as shown in Table 1 below, and the flavor was also good.

Comparative Example 1 An oil-in-water emulsion prepared in the same manner as in Example 1 was used.
Keeping the temperature at ℃, the temperature of the emulsion is 135 ℃ using Kureha type ultra-high temperature instantaneous sterilizer (Kureha Engineering Co., Ltd.)
It was held for 10 seconds and then cooled to 52 ° C by evaporation under reduced pressure. The wall of the high temperature steam mixing section was not cooled during the heat treatment. The state of kogation of this oil-in-water emulsion is shown in Table 1 below.

Comparative Example 2 An oil-in-water emulsion prepared in the same manner as in Example 2 was used.
The temperature of the emulsion was maintained at 150 ° C. for 3 seconds using a Kureha type ultra-high temperature instantaneous sterilizer (manufactured by Engineering Co., Ltd.) while maintaining the temperature at 50 ° C., and then cooled to 52 ° C. by vacuum evaporation.
During the heat treatment, cooling water was not flown and the wall of the high temperature steam mixing section was not cooled. The state of kogation in this oil-in-water emulsion is shown in 1 below.

[Effects of the Invention] According to the method for producing an oil-in-water emulsion of the present invention, the oil-in-water emulsion has excellent storage stability and workability, is suitable for distribution, has a good flavor, and has a wide range of use without causing kogation product contamination. The thing can be manufactured.

[Brief description of drawings]

FIG. 1 shows a main part of an ultra-high temperature instantaneous sterilizer used for carrying out the present invention. A cross-sectional view of the high temperature steam injection part as seen from the side in the moving direction of an oil-in-water emulsion, FIG. 2 is a sectional view taken along the line AA of FIG. 1, and FIG. 3 is a flow sheet showing an example of a step of direct heat treatment in the present invention.

Claims (3)

[Claims] 1. A method for producing an oil-in-water emulsion comprising the following steps I to III. I. Emulsification process for preparing an oil-in-water emulsion containing 1 to 70% by weight of edible oil and fat, 0.2 to 10% by weight of protein material (as protein mass) and water, and II. Mixing section equipped with steam injection means And using a device having a high-temperature steam injection part provided with a cooling means for cooling the wall part constituting the mixing part, while cooling at least a part of the wall part, Direct heat treatment step of mixing the introduced oil-in-water emulsion with high temperature steam and maintaining the temperature of the oil-in-water emulsion at 100 to 160 ° C. for 1 to 30 seconds, and III. An evaporative cooling step of cooling the oil-in-water emulsion by evaporating water in the oil-based emulsion under reduced pressure. 2. A mixing part is provided which allows the heated fluid to be circulated and allows the steam to be directly mixed with the heated fluid, and a part of the wall surface forming the mixing part has a large number of steam injection pores. An ultrahigh-temperature sterilizer configured by a porous member having a superhigh-temperature sterilizer equipped with a cooling mechanism for circulating a cooling liquid to at least a part of an outer wall surface other than the wall surface in the mixing section. . 3. The ultrahigh temperature sterilizer according to claim 2, wherein the fluid to be heated is an oil-in-water emulsion.