JPS6283858A - Production of wheat flour for cake - Google Patents

Abstract

PURPOSE:To obtain the titled wheat flour having excellent secondary processability, by heating and extruding wheat flour under specific condition while maintaining the fluidized state of the wheat flour. CONSTITUTION:When flour is supplied to a single screw or twin-screw extruder provided with an orifice die having and opening ration of >=30% and heated for 30-60sec at a screw revolution speed of 60-350rpm keeping the fluidized state of the wheat flour, optionally introducing hot air through a vent hole opened in the barrel. The heated produce is extruded to obtain wheat flour for cake heated at 60-100 deg.C.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a method for producing flour for confectionery.

[Prior art]

The secondary processability of wheat flour depends on the selection, selection, crushing, and
It goes without saying that the share is determined by the milling technique, but it has long been thought that the ripening and aging after milling and other factors are also involved. In particular, phenomena such as "floating", "baking shrinkage", and "sinking" in confectionery flour are thought to be caused by factors other than the flour milling technique.

In order to improve confectionery properties, wheat has generally been subjected to heat treatment in addition to treatment with oxidizing agents, chlorine, etc. Oxidizing agents and chlorine treatments are being eliminated due to pollution and food hygiene issues, and safe heat treatment is becoming the remaining method.

Much research has been done since ancient times on the heat treatment of wheat, and it has generally been sold as ``quenched flour.''
There are disadvantages in that there is no use for the remaining flour after the target wheat flour is separated, and that heat conduction from the surface of the wheat causes poor peeling and a reduction in flour milling yield.

For this reason, various methods of heat treating wheat flour have been studied.

Heat treatment to improve the secondary processability of wheat flour must be carried out to the extent that ``proteins do not denature'' and ``starch does not gelatinize.'' Such changes in flour components are caused by temperature,
It is determined by factors such as humidity and time, and humidity is said to be an especially important factor.

Conventionally, the heating treatment of flour is carried out continuously in a conveyor chamber. Heating methods include indirect heating in which a heating medium is passed through the jacket of the conveyor outer cylinder and stirring blades, and direct heating in which steam is passed directly into the conveyor chamber. Direct heating has the disadvantage of causing some of the powder to clump and result in overheating, while indirect heating tends to cause powder adhering to a part of the stirring blade to remain, making the processing time inconsistent and causing the powder to clump away from the stirring blade. It has the disadvantage of deteriorating the heat transfer efficiency.

Uneven quenched flour mixed with wheat flour that has been partially overheated by conveyor heating causes the disadvantage of a "sticky" or pasty texture in secondary processed products.

Although the mechanism of improving the secondary processability of wheat flour is not yet clear, in recent years extremely weak changes in starch have been emphasized as a factor other than protein denaturation, which has long been considered. For example, there is a strong theory that chlorine treatment has a selective effect on starch over protein denaturation and improves dispersibility, and the improvement in floating and sinking can be understood as a manifestation of this effect. In order to suppress protein denaturation and cause weak changes in starch during heat treatment, it is desirable to expose starch granules to high heat under conditions that do not cause gluten aggregation, that is, with low moisture content. However, the thermal conductivity of wheat flour is extremely poor, and in addition, the starch grains in flour are shaped like lenses, mainly ellipsoids with a major axis of 35 to 40μ, and granules with a diameter of 1μ.
It consists of circular parts with a diameter of 0 to 15 microns, and in order to uniformly heat these parts, it is thought to be important how to bring them into contact with the heat transfer surface efficiently. In the conveyor heating method, there is a limit to the number of times starch granules can come into contact with the heat transfer surface, and if the stirring blades are devised and the stirring is strengthened, a superheated product with an extremely long residence time will be created.

The method of heating wheat flour with an extruder is an extremely effective method because the processing conditions, ie, temperature, humidity, time, etc., can be precisely controlled.

However, extruders have the disadvantage that they apply more shearing force than conventional heating methods, causing more damage to starch granules than intended. In other words, it can be used to produce roux, pregelatinized flour, soup powder, efrea powder, etc. by intense heat treatment, but it is considered impossible to improve confectionery properties by extremely mild treatment. I came.

[Purpose of the invention]

Therefore, an object of the present invention is to provide a method for producing flour for confectionery with excellent secondary processability.

[Structure of the invention]

As a result of intensive research on the processing of flour using an extruder, the inventor of the present invention found that by setting the opening ratio of the orifice die of the extruder to 30% or more and keeping the powder in a fluidized state as it passes through the extruder. The inventors have found that the above object can be achieved and have completed the present invention.

That is, the present invention is characterized in that flour is maintained in a fluidized state using an extruder equipped with an orifice die with an opening ratio of 30% or more, and heated and extruded so that the product temperature is 60 to 100 ° C. This is a method for producing flour for confectionery.

The extruder used in the present invention may be a -shaft type or a bishaft type, but it is necessary that the aperture ratio (the ratio of the opening area of the orifice to the cross-sectional area of the screw) be 30% or more. Yes, preferably 50% or more. If the open area ratio is less than 30%, the desired fluidized state of the flour cannot be achieved.

The raw flour may be humidified to about 5 to 8% in order to compensate for the moisture scattered at the extruder tip.

The biaxial fully interlocking directional rotating extruder, which has recently been developed in the field of plastics industry, is characterized by an extremely weak calendering effect (shearing force) and self-cleaning effect, and also has a good mixing effect, making it suitable for use in the present invention. This is the most suitable device.

In general, the purpose of using a two-shaft fully interlocking directional rotation extruder for food is called extrusion extrusion, and the orifice die attached to the tip is used for high-temperature, high-pressure, short-time heat treatment. Using this device, the roux, α
It is possible to produce powdered powder, soup powder, and eflair powder. However, extremely mild processing can clog the orifice die if the material is not fluid. For this reason, it has not been possible to obtain flour suitable for confectionery by using a normal extruder as is, but the inventor of the present invention has succeeded in air-airing the flour by increasing the opening ratio of the orifice die to 30% or more. They discovered that heat treatment can be performed while maintaining the mixture in a fluidized state.

In order to keep the flour in a fluidized state, Sufu IJ, -
It is necessary to increase the rotation speed. When using a twin-screw extruder, this fluidized flour slows down inside the extruder due to the contact resistance of the barrel surface, and with a constantly reversing movement, the entire flour is divided into two parts by opposing screw flights while following a gourd trajectory. It is sent to the screw tip while being

Standard twin-screw extruder (double thread L/D=1
3), the number of flights is 24, and the number is 224 divisions = 16777
It will be divided into 216 parts. It is thought that if this and the movement equivalent to rotational movement are added, each starch granule almost certainly comes into contact with the heated barrel and is heated uniformly.

Although heating by the extruder of the present invention is a short-time process, it is characterized by the fact that there are many opportunities for contact with the outer peripheral barrel due to the mixing effect. The rotation speed is 60 to fluidize the powder.
~350 rpm, preferably 150 rpm or more is suitable. Increasing the rotational speed will shorten the residence time. In this case, use a screw with a short flight pitch, or
It is preferable to use a long one.

Although the intensity of the heat treatment is indicated by the treatment temperature and average residence time, if the L/D is short, the degree of heat treatment can also be determined by the exit temperature of the product. If L/D is long, the outlet temperature will be almost the same as the barrel set temperature.

The effect can be seen at product temperature of 60 to 100℃, but
Optimal efficacy is seen at ~95°C. Barrel temperature setting is 10
In the case of 0 to 120°C, this product temperature is achieved with an average residence time of 30 seconds to 1 minute. If the L/D is large, set the target product temperature, but if the average residence time is 1 minute or less, that is, if the L/D is small, set the barrel temperature 20 to 40°C higher than the target product temperature. is desirable.

If the throughput is increased, fluidity will be lost and the amount of heating energy from the barrel will be insufficient, so it is desirable that the throughput be 60% or less of the maximum throughput. If the amount to be processed is large, it is desirable to set the temperature higher than the target product temperature.

〔Effect of the invention〕

According to the present invention, by setting the opening ratio of the orifice die of the conventional extruder to 30% or more, the flour for confectionery with excellent secondary processability can be improved.

〔Example〕

Biaxial extruder [Toshiba Machine ■ TEM-50 type, 6 barrels, L/D=20 open (opening ratio 100%)
, A screw is used in which a probing disk is placed at the rear of the second barrel from the supply side and at the tip of the screw, and four kneading disks are placed at approximately equal intervals between both blocking disks. ] and heat-treated thin-blade flour (moisture approximately 14%) under the conditions shown in Table 1. Using each treated flour, castella was made as follows.
Texture etc. were evaluated.

Castella test composition (g) Flour 1000 Sugar 1900 Whole eggs 2100 Starch syrup 400 Water 200 Mix eggs and sugar with Hobart mixer A200 at low speed for 2 minutes.
Whisk on medium-high speed for 4 minutes. Add Nekisui, which is made by dissolving starch syrup in water, and mix on medium-high speed for 3 minutes. Add flour to this and mix for about 30 seconds to make a batter with a specific gravity of about 0.5. Use this as a frame for 8 pieces (555 crucian carp x 375 mm x
7.2) Pour into a castella castella pot at 220℃.25
Castella was made using the usual castella firing method, which included removing bubbles three times every minute. The results are shown in Table 1.

Table 1 1-
too Slightly concave Normal (control) 2 20, 100 88
112 Convex Good 3 60
100 g2 110 Convex Good 4 60 110 8
6 116 Convex Good 5 60
120 97 111 Flat Slightly pasty Snake 16 60 130
99 109 Slightly concave Adhesive c1 Example 2 Using the twin-screw extruder (barrel temperature 100°C) used in Example 1, the feed rate was maintained at 20 kg/h, and the rotation speed of the Sufu IJ +'- The fluidization state of the flour was investigated by changing the A pigment (methyl red Ig) was spot-injected into flour, the time when the pigment concentration reached its maximum (considered to be the retention time) was recorded, and the flour discharged at that time was subjected to a Pelaker test. When flour is flattened by crushing it with a spatula, the state of dispersion of foreign substances, i.e., pigments, or the fluidization state of the flour can be clearly seen. The results are shown in Table 2.

Table 2 1 30 81 95 Large spots 2
50 83 55 Many spots 3
100 86 28 Slightly spotted 4
200 88 1g
Homogeneous Table 5 20 30 80 82
Homogeneous 21 30 10
0 90 Homogeneous 22 6
0 80 80 Homogeneity Test Example゛ The total number of viable bacteria and the number of heat-resistant bacteria of the flour treated in the above example, as well as the texture of a cake made using this flour as follows, were evaluated.

Cake test formulation (gun Wheat flour 100 Sugar 100 Whole egg 100 Water Texture is the average score when evaluated by 15 panelists on a scale of 100 points. The results are shown in Table 6.

Example 4 Using the twin-screw extruder used in Example 1, processing was carried out at a rotation speed of 200 rpm, a barrel temperature of 100° C., a flour feed rate of 140 kg/h, and the opening ratio of the orifice was changed. Castella test was conducted using the obtained treated powder. The results are shown in Table 7.

Claims (2)

[Claims] (1) Using an extruder equipped with an orifice die with an opening ratio of 30% or more, flour is kept in a fluidized state,
A method for producing flour for confectionery, characterized by carrying out heating extrusion treatment so that the product temperature is 60 to 100°C. (2) Claim No. 1 (2) characterized in that heated air is blown from a vent provided in the barrel of the extruder.
The method described in section 1).