JPH0741793A - Powdery fat or oil and preparation thereof - Google Patents

Abstract

PURPOSE:To obtain a powder fat or oil excellent in storage stability by forming a starting material contg. a fat or oil into a melt having water and/or an org. solvent homogeneously dispersed therein in an extruder, and immediately ejecting the melt. CONSTITUTION:A starting material contg. a fat or oil is melted in the presence of water and/or an org. solvent under a high pressure at a high temp. in an extruder to form a melt having the coexistent water and/or org. solvent homogeneously dispersed therein in a liquid state. Immediately thereafter, the melt is ejected from a die into a zone wherein an atmospheric or lower pressure is maintained to explosively evaporate the coexistent water and/or org. solvent while solidifying the melt of the starting material to form a surface film. Thus, a powdery fat or oil wherein the surface of the particles are smooth is obtd. The surfaces of the particles are smoother than those of particles prepd. by spray drying, freeze drying or the like. This powder is a stabilized fat or oil powder wherein the fat or oil is homogeneously and stably entrapped in the starting material.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a powdery fat and oil excellent in storage stability and a method for producing the same.

[0002]

2. Description of the Related Art In recent years, the physiological activity of fats and oils containing unsaturated fatty acids has been attracting attention, and therefore, these fats and oils are used in health foods or dietary supplements, feeds, pharmaceuticals, etc.
Widely used. However, these oils and fats are unstable with respect to oxidation, and it is necessary to handle them so as not to be oxidized, and the handling thereof is complicated. In addition, since the use is limited when it is in a liquid state, oils and fats are pulverized.

Conventionally, as a manufacturing method for powdering fats and oils, there are a spray type, a crushing type and a coating type. The spray method is the most general method, and a method of emulsifying oils and fats with proteins, carbohydrates, emulsifiers and the like and then dry spraying is adopted. However, this method is an operation for increasing the surface area, and particularly in the case of oils and fats containing highly unsaturated fatty acids, they are easily oxidized and have poor storage stability.

The crushing method requires a lot of labor such as emulsification, freeze-drying, and crushing, and it requires a great deal of cost because a freeze-dryer is used. With the coating method of encapsulating microcapsules, there is a risk that the film formed will break and oil and fat will elute,
Also, the application is limited in terms of cost. Extruders are also used in the production of powdered fats and oils.

For example, as a method for increasing the oxidation stability of fats and oils using an extruder, a raw material powder rich in starch is used together with an appropriate amount of water and 40% or less by weight of fats and oils without adding an emulsifier, and a biaxial type extruder There has been proposed a method for producing a fat-and-oil-processed starch (Japanese Patent Publication No. 1-44306), which is characterized in that the starch is put into a ruder and extruded from a die at the end of the barrel.

However, in this method, the substance to be coexisted with the fats and oils is limited to the raw material powder rich in starch, and the product extruded from the die is an expanded product. In order to pulverize the expanded product, a drying and crushing process is essential and the process is complicated. In addition, the pulverized product of this expanded product has a large particle surface area, and particularly in the case of highly unsaturated fats and oils, there is a high possibility that it will be easily oxidized.

[0007]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a stabilized oil and fat powder and a method for producing a large amount of the stabilized oil and fat powder in a short time.

[0008]

The present invention directly produces powdered fats and oils by using an extruder. A raw material containing fats and oils is charged into an extruder, kneaded, heated and pressurized to form a uniform melt of the raw materials, which is ejected from pores to granulate highly stable powdery fats and oils. The obtained powdery fat and oil is dried if necessary. In the present invention, drying /
The grinding process is not essential.

The raw material containing fats and oils charged into the extruder is melted by high temperature and high pressure while advancing while being kneaded in the barrel to form a uniform melted mixture of fats and oils. This molten mixture is atomized from an extruder discharge hole having at least one discharge hole at the tip of the last barrel. During ejection, volatile substances such as water in the raw material evaporate instantaneously, and the atomized raw material solidifies and changes into a fine powdery fat with a thin film of the proteins contained in it. To do.

The obtained oil / fat powder is a stabilized oil / fat powder in which the particle surface is smoother than particles produced by a spray drying method or a freeze-drying method, and the oil / fat is uniformly and stably incorporated in the raw material. is there. Further, according to the present invention, it is possible to save the labor, shorten the time, and reduce the manufacturing cost by directly manufacturing the powdered fat and oil using the extruder. That is, a large amount of powdery fats and oils can be produced in a short time as long as the raw materials having an arbitrary composition are supplied to the extruder.

In the present invention, animal oils such as fish oil, lard, beef tallow, corn oil, soybean oil, rapeseed oil, linseed oil, sesame oil, vegetable oils such as cottonseed oil, olive oil and palm oil, and oils such as synthetic oils are used as the oil and fat raw material. To do. These oils and fats may be of any origin, and their chemical structure such as carbon number, degree of unsaturation, chemical modification, etc. are not limited, but non-volatile oils are preferable. Further, the purity may be a refined oil or fat, or a mixture of a plurality of fatty acid components such as fish oil, and further contains substances other than oil and fat such as water and protein such as fish and shellfish extract. Is also good.

The raw materials to be put into the extruder together with the oils and fats are those containing sugars such as starch and cellulose, proteins and decomposed products thereof, and more specifically, soft flour, strong flour, rice flour, rice bran, wheat dust powder. In addition to powdered materials such as starch gluten, soy protein, soy lecithin,
Fish meat, livestock meat, minced meat thereof, etc. are arbitrary, and the selection, combination, mixing ratio, etc. of each component of these raw materials are also arbitrary.

The water content of the raw material composition is a parameter related to the particle size of the product, and it is necessary to adjust the water content according to the desired particle size. The water content can be adjusted by adding water from outside in addition to the water contained in the raw material. In some cases, an organic solvent such as ethanol, hexane or acetone can be used instead of water. By appropriately selecting each component of the raw materials, it is possible to produce various particles by varying the particle size, density, surface condition, hardness, color tone, flavor, etc. of the product particles.

Further, regardless of which raw material component is used, solid, powder or liquid vitamins, minerals, flavors, antioxidants, swelling agents,
Additives such as a thickener, a surfactant, an emulsifier, and a coloring agent can be appropriately used. The mixing of these additives and the raw material composition may be performed in advance, or may be performed in an extruder.

In the present invention, the raw material is a composition comprising a fat and oil raw material and a mixture of other blended raw materials and / or various additives, and the raw material composition having a controlled water content is heated at a high temperature in an extruder. After melting under high pressure, the particles are discharged from the die into a zone maintained at atmospheric pressure or lower pressure to obtain almost spherical smooth particles. By transferring the raw material by the extruder, the temperature and the pressure are gradually increased, and the temperature of the raw material becomes the highest before the die part. Here, the raw material is in a molten state, and the water contained in the raw material is kept in a liquid state and is uniformly dispersed in the molten raw material. When an organic solvent is present, the organic solvent is in the same state as water.

Because of this state, it is possible to explosively introduce from the die section into the zone maintained at atmospheric pressure or thereby at low pressure. At the time of this discharge, the temperature of water is much higher than its boiling point, and the water, which is still in a liquid state due to pressure, vaporizes immediately when it comes out from the discharge port or die hole under atmospheric pressure or lower pressure and vaporizes. And escape from the raw material. Instantly converting water to steam in this manner instantaneously cools the raw materials as a result of the water and the raw materials releasing latent heat for vaporizing the water. In addition, when water escapes as steam from the raw material, it leaves behind a jetting hole after the water inside the raw material evaporates, thus allowing the water to continue to evaporate and further reduce the moisture content of the raw material particles. In order to adjust the water content of the obtained raw material particles, a particle drying step is provided if necessary.

An inert gas can be introduced into the extruder in order to more uniformly disperse the raw material mixture in a molten state in the extruder and to further promote vaporization of water when discharged from the die section. . The introduction of the inert gas into the extruder can be carried out by means known in the art before the present application. The introduction of the inert gas promotes the escape of water vapor from the raw material, and as a result, the moisture content of the raw material particles can be further reduced. Therefore, the step of drying the particles can be omitted.

In the present invention, single-screw and twin-screw extruders can be used. Extruder consists of feeder, barrel, screw, die,
It consists of five heaters (or cooling units), and the characteristics of the heaters (or cooling unit) are determined by the number and shape of the screw shafts and the mutual positional relationship (in the case of multiple screws). One screw is uniaxial type, two screws are biaxial type, and the substance transfer is only by the friction between the barrel and the substance in the uniaxial type, but in the biaxial type, they rotate by meshing with each other. In addition to the pushing and sliding effects of the screw, the manufacturing capacity of the uniaxial type is also affected by the water content, oil content, pressure, etc. of the raw material, but the biaxial type is free within a certain range and is affected by the water content. Instead, it enables stable operation.

Therefore, it is preferable to use a twin-screw extruder in the present invention, since a twin-screw type extruder can be satisfactorily operated even with a raw material having a high oil content such as powdered fats and oils. However, even if a uniaxial type extruder is used, it can be satisfactorily processed if the raw material water content is appropriate. Twin-screw extruders suitable for the present invention are commercially available and well known to those skilled in the art. The temperature and pressure of the raw material are increased to almost the temperature and pressure in front of the die part by propelling the raw material along the barrel by the extruder by the mechanical force of the feed part for introducing the raw material and the screw. It includes a pressure rectifying section which is either a fixed or variable orifice such as a high compression section and a variable die.

The compacted material is then rapidly expanded into a zone maintained at or below atmospheric pressure to granulate the melt. The dispersed fine particles are collected or classified, and further conveyed to a secondary drying device for adjusting the water content. As described above, the method of the present invention advances the raw material containing water in the elongated cylinder, and applies gradually increasing pressure to the advancing raw material, gradually increases the temperature of the raw material, and lowers the temperature of the raw material from the highest pressure region in the cylinder. It is characterized in that the raw material is cooled by suddenly discharging it into a low-pressure region to form a smooth surface into particles, and instantaneously vaporizing the water content of the raw material.

That is, the raw material is fed into the feed barrel of the extruder by a feeder, and sequentially transferred forward by the screw in the barrel. At that time, the mechanical pressure is increased and applied to the raw material so that this pressure value is always larger than the vapor pressure of the water in the raw material so that the water remains liquid. Above the boiling point, the material is given a sufficient compression action which is increased in the apparatus.
The screw is rotated at a relatively high speed to heat the raw material and the water contained therein. When the rotation speed of the screw is relatively large, not only the raw material can be rapidly heated, but also the raw material can be sufficiently stirred while passing through the inside of the apparatus.

Further, if the water content in the raw material is kept liquid during the passage of the raw material in the apparatus, the total thermal conductivity coefficient can be increased as compared with the case where it is evaporated. Further, if the water content of the raw material is kept liquid during the temperature raising step, it is possible to sufficiently prevent the initial phenomenon of overheating the raw material on the barrel wall, the screw surface, or the shaft surface. As a result, the residence time of the raw material at the maximum temperature immediately before the die part becomes extremely short, which is hardly measurable, and the problem of charring does not occur.

[0023]

EXAMPLES Next, examples of the present invention will be described. The present invention is not limited to the examples. Example 1 40 parts by weight of water was added to commercially available 2
Supplied to the shaft extruder, the screw speed is 150r
pm, the installation temperature of the barrel heater is 150 ° C, 200
The temperature was gradually increased to 0 ° C., and the treatment was performed at the installation temperature of the tip barrel of 250 ° C. The pressure at the tip was 2 kg / cm ² . It was discharged from the die section under normal pressure. From the extruder,
The temperature of the particles immediately after discharge was 150 ° C., and the dropped particles were collected in a sky tank to obtain a powdered oil and fat. This powder has a particle size of 1 mm or less at 80% and its average particle size is 150
The particles were spherical and had a smooth surface of μm.

[0024]

[Table 1] Oils and fats were immediately extracted from this powder, and the POV was measured to be 3.2 meq / kg, and deterioration of the oils and fats by this method was not observed. Further, this powdery fat and oil was allowed to stand for 1 week at 5 ° C. in an open system, but no fish oil odor was observed and it was good.

[0025]

EFFECTS OF THE INVENTION According to the present invention, it is possible to provide a powdery fat that has a smooth particle surface and is stable against oxidation. Furthermore, by directly producing powdered fats and oils using an extruder, it is possible to form a smooth particle surface, which enables further labor saving and cost reduction, and makes powdered fats and oils excellent in storage stability in a short time. It can be provided in large quantities.

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[Procedure amendment]

[Submission date] September 6, 1993

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0021

[Correction method] Change

[Correction content]

That is, the raw material is supplied into the feed barrel of the extruder by the feeder, and sequentially transferred forward by the screw in the barrel. At that time, the mechanical pressure is increased and applied to the raw material so that this pressure value is always larger than the vapor pressure of the water in the raw material so that the water retains the liquid. The screw is rotated at a relatively high speed to heat the raw material and the water contained therein. When the rotation speed of the screw is relatively large, not only the raw material can be heated quickly, but also the raw material can be sufficiently stirred while passing through the inside of the apparatus.

[Procedure Amendment 2]

[Document name to be amended] Statement

[Name of item to be corrected] 0022

[Correction method] Change

[Correction content]

Further, if the water content in the raw material is always kept liquid while the raw material passes through the inside of the apparatus, the total thermal conductivity coefficient can be increased as compared with the case of evaporation. further,
By keeping the water content of the raw material in a liquid state during the temperature increasing step, it is possible to sufficiently prevent the phenomenon of overheating the raw material on the barrel wall, the screw surface, or the shaft surface. As a result, the residence time of the raw material at the maximum temperature immediately before the die part becomes extremely short, which is hardly measurable, and the problem of charring does not occur. ─────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] June 2, 1994

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0021

[Correction method] Change

[Correction content]

That is, the raw material is fed into the feed barrel of the extruder by a feeder, and sequentially transferred forward by the screw in the barrel. At that time, the mechanical pressure is increased and applied to the raw material so that this pressure value is always larger than the vapor pressure of the water in the raw material so that the water retains the liquid. The screw is rotated at a relatively high speed to heat the raw material and the water contained therein. When the rotation speed of the screw is relatively large, not only the raw material can be heated quickly, but also the raw material can be sufficiently stirred while passing through the inside of the apparatus.

[Procedure Amendment 2]

[Document name to be amended] Statement

[Name of item to be corrected] 0022

[Correction method] Change

[Correction content]

Further, if the water content in the raw material is kept liquid during the passage of the raw material in the apparatus, the total thermal conductivity coefficient can be increased as compared with the case where it is evaporated. Further, by keeping the water content of the raw material in a liquid state during the temperature raising step, it is possible to sufficiently prevent the phenomenon that the raw material is overheated on the barrel wall, the screw surface or the shaft surface. As a result, the residence time of the raw material at the maximum temperature immediately before the die part becomes extremely short, which is hardly measurable, and the problem of charring does not occur.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kazuhiko Hata 559-6 Kitano-cho, Hachioji-shi, Tokyo Inside Japan Central Research Institute

Claims (3)

[Claims] 1. Stabilized oil and fat powder having a smooth particle surface. 2. A stabilized oil and fat powder which does not contain an emulsifier and has a smooth particle surface. 3. A melt obtained by melting a raw material containing fats and oils at high temperature and high pressure in an extruder in the presence of water or an increasing solvent, and coexisting water and / or organic solvent is a liquid and uniformly dispersed. Was immediately discharged from the die portion to a zone maintained at atmospheric pressure or at a pressure lower than that to explode the coexisting water and / or organic solvent and melt it. A method for producing a powdery fat or oil, which comprises solidifying a raw material to form a film on the surface.