JPH0440981B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a food extrusion method and apparatus for extruding food materials containing fats and oils.

(Prior Art) As an extrusion molding and shaping technology for foods, there is an extrusion processing apparatus as shown in FIG. This device is for porous puffed snack food, and mixes, shears, heats, pressurizes, and kneads food materials in a cylinder 2 and two screws 3 in it to make them melt and flow.
It is extruded while being formed into the desired shape.

(Problems to be Solved by the Invention) In the prior art described above, the die 5' has a short die hole, and merely shapes the material to be extruded, and has no other function, and is not used for more advanced food production. For example, it is extremely difficult to organize and continuously shape plant proteins, as well as texture and shape other livestock meat, fish meat, and the like.

(Means for Solving the Problems) These problems can be solved to some extent by using a long die with a long material flow distance as the forming die. In other words, if the molten material is allowed to flow while being compressed and cooled within the long die, excessive foaming of the extrudate due to evaporation of water in the material and unstable bumping phenomenon at the die outlet can be prevented, and the gap between the material and the inner peripheral surface of the long die can be prevented. Due to the flow resistance and viscosity of the material, a viscous flow velocity distribution (same shape as in Figure 10) generates shearing force and pressure, resulting in orientation along the flow direction and fiberization (a state in which the orientation is fixed). Organization takes place.

However, the concept of a die is that the inner circumferential surface of the die hole is generally formed as smooth as possible. It is possible to process soybeans and grains that do not contain oil, but in the case of oil-containing food materials such as oil-added vegetable protein materials made by adding oil to defatted soybean flour and oil-containing materials such as livestock meat and fish meat, it is possible to process soybeans and grains that do not contain fat. Oil and fat in the material seeps out, causing separation and segregation, and the flow resistance between the inner peripheral surface of the die and the flowing material becomes extremely low, resulting in wall slippage, which occurs continuously or intermittently as shown in Figure 11. A so-called plug flow occurs, and the viscous flow of the material disappears.
Since shearing force and pressure are not generated, effects such as orientation and fiberization cannot be expected.

Therefore, when performing structured molding of oil-containing food materials (including oil-added materials), even if oil and fat seep out and separate and segregate, the part of the extruded material in contact with the inner peripheral surface of the die will If sufficient flow resistance is present, the above-mentioned problems can be solved.

That is, the specific structure of the problem-solving means in the method of the present invention is characterized by extruding the oil-and-fat-containing food material in the extruder 1 into the long die 5, cooling it under compression, and removing the contact portion with the inner circumferential surface 7 of the long die. The device of the present invention is characterized in that the material is made to flow while actively applying flow resistance.The device of the present invention is also characterized by the fact that the inner peripheral surface 7 of the long die 5 at the tip of the extruder 1 has irregularities in the direction of material flow. The point is that a flow resistance imparting surface A is formed which gradually becomes smaller.

(Function) The fat-containing food material heated, sheared, kneaded, and mixed in the extruder 1 to a molten state and extruded into the long die 5 will not melt inside the long die 5 even if the fats and oils ooze out and segregation occurs. Due to the flow resistance imparting surface A of the peripheral surface 7, sufficient flow resistance is applied at the inner peripheral surface contact portion, resulting in a viscous flow, and the contained water vapor is condensed by being cooled under pressure.

(Example) Hereinafter, an example of the present invention will be described based on the drawings.

In FIGS. 1 to 7, an extruder 1 has two screws 3 (or one screw 3) arranged in a cylinder 2, and a long die 5 (cider or sizing die) connected to the tip of the cylinder 2 via a die adapter 4. is attached, and a breaker plate 6 is arranged inside the die adapter 4.

The cross-sectional shape of the inner peripheral surface 7 (molding surface) of the long die 5 is substantially the same as the final product shape over the entire length in the longitudinal direction, and in addition to the rectangular cross-section, the cross-sectional shape shown in FIGS. It is possible to mold products with shapes as shown in (7).

In the case of an embodiment in which the inner circumferential surface 7 has a rectangular cross section, one side wall of the circumferential wall is configured as a movable wall, and a movable wall 7b is arranged inside the box-shaped fixed wall 7a.
A pushing bolt 8 passing through the fixed wall 7a is screwed onto the fixed wall 7a, and the tip of the set bolt 9 screwed onto the fixed wall 7a is brought into contact with the movable wall 7b by pushing the pushing bolt 8. It can slide up and down without any gaps, allowing the cross-sectional shape of the product to be changed.

A passage 10 through which a cooling medium flows is formed in the wall of the long die 5, so that the temperature of the die can be controlled to a temperature required for molding. Incidentally, if necessary, a cooling medium passage may also be formed in the movable wall 7b.

When the long die 5 has a movable wall 7b, the inner circumferential surface 7 of the long die 5 is a surface facing the movable wall 7b and the fixed wall 7a,
When there is no movable wall, the flow resistance imparting surface A is formed on the entire surface. This flow resistance imparting surface A has a satin finish (by shot peening, etc.) as shown in Fig. 3, a groove perpendicular to the material flow direction as shown in Fig. It is formed by forming grooves in two directions (knurling grooves) with an angle of .degree. to create an uneven surface, or by pasting a sandpaper-like material.

The flow resistance imparting surface A can be formed with the same amount of unevenness over the entire length of the long die 5. On the exit side where the product is extruded in the final shape, it can be made a smooth surface without unevenness in order to adjust the surface shape of the product. Preferably, conversely, it is preferable to make the unevenness large on the starting end side where the material fluidity is high in order to achieve the organizing effect more efficiently and quickly. Incidentally, the size and density of the unevenness, the depth of the grooves, the pitch, etc. are appropriately selected depending on the material.

The flow resistance imparting surface A shown in FIG. 6 has a degree of roughness that changes stepwise from the starting end to the exit of the long die, and the rough knurled surface A, small, medium, coarse knurled surface B, and A narrow knurled surface c is formed, and the amount of unevenness gradually decreases. The exit side of the fine knurled surface c is a smooth surface d.

The degree of roughness of the flow resistance imparting surface A shown in FIG. 7 changes steplessly, and the groove depth of the knurling gradually becomes shallower as it goes toward the exit side.
Near the exit, the groove disappears and becomes a smooth surface d.

FIG. 8 shows an example of the tip of an extruder for forming cylindrical products, in which a long die 5 is attached to the tip of a tube die 11, and both dies 11, 5
A mandrel 12, 12' is disposed therein, respectively. Flow resistance imparting surface A of the long die inner peripheral surface 7
This includes the outer circumferential surface of the mandrel 12', and the outer circumferential surface of the mandrel is also formed with unevenness with uniform or gradually decreasing roughness.

In extrusion processing by the extruder 1, oil-containing materials such as soybean flour, livestock meat, fish meat, etc., or defatted soybean flour and added oils and fats, etc. are supplied from the feeder of the cylinder 2, and while heating with a heater outside the cylinder 2, the oil-containing materials are fed into the screw 3. After mixing, shearing, pressurizing, and kneading by rotation to bring the material into a high-temperature molten fluid state, it is extruded into a long die 5 through a die adapter 4.

The molten material that has entered the long die 5 is subjected to the cooling action of the long die 5 while being subjected to the pressing force from the screw 3, and flows within the long die 5 toward the exit side under such an environment.

During the flow, the inner circumferential surface contact portion of the material is subjected to flow resistance by the flow resistance imparting surface A of the long die inner circumferential surface 7, and the material moves forward while becoming a viscous flow. This flow resistance causes the fluid material to become oriented and fiberized in the direction of flow, thereby promoting organization. Also,
The temperature of the fluid material is gradually lowered by cooling, and the water vapor contained therein is condensed.

Furthermore, the taste of livestock meat is largely influenced by the type of fats and oils it contains rather than the quality of the meat itself, so by making it possible to add fats and oils, it is possible to add various types of fats and oils to inexpensive mother meat to create delicious meat products. It can be done.

(Effects of the Invention) According to the present invention detailed above, the fat-and-oil-containing food material extruded from the extruder 1 into the long die 5 is
Since flow resistance is actively applied to the contact portion from the flow resistance applying surface A while flowing inside the long die 5,
Even if the contained fats and oils seep out or separate and segregate, a viscous flow can be generated, and by applying pressure and cooling, the material is oriented along the flow direction and fiberized, promoting organization. Molding and shaping can be achieved with high quality and stability. Also,
By making it possible to add various oils and fats, it is possible to provide foodstuffs with excellent texture.

[Brief explanation of drawings]

Figures 1 to 7 show examples of the present invention, Figures 1A and B are a cross-sectional side view and a cross-sectional plan view of the extruder tip, respectively, and Figure 2 is a cross-sectional view taken along the - line in Figure 1A. , Figures 3 to 7 show five examples of flow resistance imparting surfaces, Figures 3 and 4 are plan views, Figures 5 to 7 are perspective views, and Figure 8 shows an extruder for cylindrical products. 9(1) to (7) are sectional views showing seven examples of the cross-sectional shape of the product. FIG. 10 is an explanatory drawing showing viscous flow.
The figure is an explanatory diagram showing plug flow. 1... Extruder, 2... Cylinder, 3... Screw, 5
...Long die, 7...Inner circumference.

Claims (1)

[Scope of Claims] 1. Extruding the fat-containing food material in the extruder 1 into the long die 5, cooling it under pressure, and causing it to flow while actively applying flow resistance to the contact portion with the inner circumferential surface 7 of the long die. A food extrusion processing method characterized by: 2. On the inner peripheral surface 7 of the long die 5 at the tip of the extruder 1,
A food extrusion processing apparatus characterized in that a flow resistance imparting surface A is formed in which irregularities gradually become smaller in the direction of material flow.