JP4473177B2 - Method for producing wet corn flour and wet corn flour - Google Patents

Description

  The present invention relates to a method for producing wet corn flour in which corn is treated under specific conditions and wet corn flour. The invention relates to a method for producing wet corn flour, which can obtain a wet corn flour with improved flavor and physical properties, and can be expected to expand use for various foods, and further increase demand.

  In general, corn is crushed by dry milling (dry milling (grinding)) without using water, removing the skin and germs, and then corn grits and (dry) corn flour as raw materials for some foods. It's being used. That is, corn kernels are coarsely crushed by dry milling, and the skin and germ on the surface of the corn are removed by wind screening and sieving, and the endosperm portion of the corn is used as flour.

  However, dry milling corn grits and corn flour have a distinctive grainy odor, taste, and roughness. Moreover, in the swelling property at the time of baking a confectionery and cakes, it is inferior compared with wheat flour and rice flour. For these reasons, foods that can be used as the main material or auxiliary material have been limited. In particular, it cannot be used for rice crackers and bakery products that require high swelling.

  Various methods for producing corn flour and the like by a so-called wet method in which cereals are treated in a solvent (including water) in order to remove the grain odor and taste are proposed (Patent Documents 1 to 3, etc.).

  Patent Document 1 describes a method in which an organic solvent resistant protease is allowed to act on a grain granule or powder in an organic solvent alkaline solution.

  Patent Document 2 describes a method of “heating raw cereals in an alkaline aqueous solution or treating with an alkaline aqueous solution containing alcohol”.

  Patent Document 3 states that, “After removing the skin and germ from corn by dry milling, a part mainly consisting of endosperm is obtained and immersed in warm water at about 40 to 65 ° C. for 1 hour or more, Grinding to 40 mesh or less in the presence of water, immediately adding endopeptidase, allowing it to act for 2 hours or more with stirring, and then dehydrating and drying if necessary. "

  However, these methods had to use an alkaline solvent, an organic solvent, and a special enzyme.

  On the other hand, corn is also refined into corn starch by wet milling (wet milling (milling)) and used as a raw material for food and industry.

  Wet milling is a method in which corn kernels are soaked in sulfite and lactic acid, then coarsely crushed, and the emulsion (mill starch emulsion) obtained by separating the skin and germ is further centrifuged to separate proteins.

  However, corn starch refined by wet milling does not have grain odor or taste, but it has almost no corn flavor because it is almost free of protein, and when used in rice confectionery, etc. Due to the sticking, the fabric cannot be made. After all, the food which can be used for these reasons was limited.

In addition, the starch and protein mixture obtained from the intermediate product before protein separation after sulfite lactic acid immersion, rough crushing, and separation of skin and germ in wet milling uses chemicals during soaking, so even if washed, the chemical odor And the astringent taste remains. In addition, since starch and protein are separated by sulfite lactic acid soaking in this product, in the case of rice confectionery, etc., the steaming process is difficult due to the adhesiveness of gelatinized starch, and it could not be used as flour .
Japanese Patent Laid-Open No. 10-210942 (Claims etc.) JP 63-14670 (Claims etc.) JP-A-52-57352 (Claims etc.)

  In view of the above, the present invention does not have defects such as a unique grain odor, savory taste, and rough texture, has improved flavor (appropriate corn flavor), and has improved physical properties such as swelling properties. It is an object (problem) to provide a novel wet corn flour production method that is not described in the above-mentioned prior art, and that can obtain corn flour.

  As a result of intensive studies to solve the above-mentioned problems, the present inventors have soaked corn in warm water, coarsely crushed, then removed germ and skin, and obtained a wet corn obtained by a method of removing hard endosperm coarse particles As a result of finding that the flour can significantly remove the unique grain odor, taste, and rough texture, the inventors have devised a method for producing a wet corn flour having the following constitution.

    It includes the following steps.

    1) A warm water soaking process in which corn kernels are soaked in warm water at a temperature of 70 ° C. or less.

    2) A crushing step of crushing corn grains after the warm water immersion of 1) above.

    3) A purification step of removing the germ and skin of the composition of 2) above, removing 50 mesh-on hard endosperm coarse particles, and further washing.

  In the purification step, it is more preferable to remove 150 mesh-on hard endosperm coarse particles.

  Moreover, the conditions of hot water immersion shall be pH 4-8, and it shall be temperature: 45-70 degreeC x time: 3-50h, Furthermore, it shall be pH5-7, and temperature 55-65 degreeC x time: 3 to 30 h is preferable.

The wet corn flour of the present invention has a soluble component amount in 55 ° C. warm water (hereinafter referred to as “hot water soluble component amount”) of 3% (dry matter weight basis) or less (preferably 1% or less) and 200 g (dry matter weight basis). ) / L of a sample prepared by adding a few drops of a staining solution to an aqueous solution and stirring, has a volume fraction of protein-bound starch (hereinafter referred to as “protein-bound starch amount”) that is fractionated as an intermediate separation layer by centrifugation. ˜100 vol% (desirably 50 to 90 vol%).

In the above, when the amount of hot water soluble component is greater than or equal to a predetermined value, when used as a food raw material, easily remain harsh taste and grain odor. In addition, if the amount of protein-bound starch is too small, problems such as excessive stickiness in the steaming process (pre-gelatinization) in rice crackers and insufficient slurry viscosity before pre-gelatinization during batter preparation occur. Therefore, it is difficult to satisfy the general required characteristics of flour.

  The corn flour having the above-described configuration can be easily manufactured by, for example, the wet corn flour manufacturing method having the above-described configurations.

  Since the wet corn flour having such a structure has a small amount of hot water-soluble components, it is difficult to cause problems of gummy taste and grain odor. Further, since the remaining amount of protein-bound starch is large, gelatinized starch does not exhibit adhesiveness during the production of rice crackers and the like, and the steaming process is facilitated. In addition, the wet corn flour of this structure can be manufactured easily by each said manufacturing method, for example.

  And the wet corn flour which has the said specific characteristic and composition is contained as a main raw material or an auxiliary | assistant raw material, and can be used conveniently for all foodstuffs, especially rice crackers and bakery products.

  The wet corn flour obtained by the above production method can be hydrolyzed and used as a saccharified product, and further as a saccharified product containing a protein hydrolyzate.

The wet corn flour produced by the method of the present invention, which undergoes a step of removing and washing hard endosperm coarse grains from the coarse crushed material obtained by crushing a hot corn soaked product of corn grain, , below the hot water soluble component is 3% (dry weight basis), protein binding amount of starch has a novel compositional characteristics 40-100% as shown in examples below, a unique cereal smell and astringent Taste and rough texture can be greatly removed, the flavor is good, and it is well swollen and other physical properties are improved.

  In addition, since the process is simple and no alkaline solvent, organic solvent, or special enzyme is used, wet corn flour with improved physical properties can be produced at low cost.

  Furthermore, since the method for producing wet corn flour of the present invention does not use chemicals during immersion, there is no chemical odor or astringent taste.

  Naturally, the wet corn flour obtained by the production method of the present invention can be expected to expand its use as a main ingredient or auxiliary ingredient of various foods, or to increase demand.

  Hereinafter, the structure of the manufacturing method in the wet corn flour of this invention is demonstrated concretely.

  1) Hot water immersion step: A step of immersing corn grains in warm water of about 70 ° C. or less.

  The kind of corn is not particularly limited, and various kinds such as normal, waxy, high amylose, white, yellow, dent and flint can be used.

  As the corn grain, a grain from which impurities, dust and the like are removed by selection is usually used. Corn grains include those from which crushed materials, germs and skins have been removed. In addition, the corn grain is preferably a corn grain whose surface is sterilized with steam or the like and is less contaminated with microorganisms.

  Here, warm water means a temperature exceeding normal temperature (room temperature). Moreover, the conditions of warm water immersion will not be specifically limited if starch is the conditions which do not gelatinize. In addition, the gelatinization start temperature of corn is set to 62.0-72.0 ° C (Jiro Jiro Kuni "Starch Science Handbook" (1977) Asakura Shoten, p37 Table 3.5). The conditions of this hot water immersion are from the viewpoint of productivity, pH is about 4-8, temperature: about 70 ° C. or less × time: about 3-50 hours, and from the viewpoint of productivity and sure prevention of gelatinization. The pH is preferably about 5 to 7, and the temperature is preferably about 55 to 65 ° C. and the time is about 5 to 30 hours. That is, if the pH is too high or too low, off-flavors such as bitterness, astringency and astringency tend to occur.

  Here, as the pH adjuster, an acidic agent or a basic agent such as hydrochloric acid, lactic acid, caustic soda, sodium carbonate, or sodium bicarbonate can be preferably used.

  If the temperature is too low, the dipping (corn grain swelling) time becomes long, and if the temperature is too high, gelatinization tends to occur.

  Moreover, it is preferable to perform this warm water immersion process, without adding a chemical | medical agent. That is, the addition of chemicals is preferably kept to a minimum only for pH adjustment.

  2) Crushing process: The corn grain after the hot water immersion of 1) is roughly crushed.

Crushing is preferably performed under conditions that do not disrupt the germ. For example, it is carried out by a bower or an enterator (disc rotating crusher). For example, the rotational speed when using the entrator is about 1000 min ⁻¹ .

  3) Purification step: The germ and skin of the composition of 2) above are removed, and the hard endosperm coarse particles are removed and further washed.

  Germ removal is performed, for example, by sieving, hydrocyclone, flotation separation, or the like.

  Further, the removal of the skin is performed by sieving such as bent sheave. The sieve mesh at this time is usually 10 to 40 mesh, preferably 20 to 30 mesh.

  The hard endosperm coarse particles are removed by sieving such as bent sheave or vibrating flat sieve. The particle size to be removed is preferably 50 mesh on, 100 mesh on, and more preferably 150 mesh on. In other words, the smaller the sieve mesh, the higher the removal rate of hard endosperm coarse particles, which is desirable in terms of physical properties. However, if the sieve mesh is too small, the yield of the product (corn flour) relative to the raw material (corn kernel) Is undesirable.

  The relatively soft endosperm fine granules (endosperm fine granules) obtained in this way have good physical properties because the protein remains as a tissue around the starch.

  On the other hand, hard endosperm coarse grains contain a lot of protein, but since this is removed, grain odor and taste are greatly reduced.

In addition, the second coarse crushing can be performed after the germ removal. For this, the same apparatus or impact mill as in the first crushing can be used. For example, the rotational speed when using an entrainer is about 1500 min ⁻¹ .

  The removal of germ, skin, and hard endosperm coarse particles may be continuously performed in the same step (same sieving device). Moreover, these removed germ, skin, and hard endosperm coarse particles can be introduced and used in the wet milling dipping process or each process, and can be made more economical.

  Next, the soft endosperm portion from which the germ, skin, and hard endosperm coarse particles have been removed is washed by a conventional method to obtain wet corn flour (product).

  Washing can be performed, for example, by a combination of a countercurrent washing system using Dravaru, hydrocyclone or the like, slurry agitation by batch, and dehydration. Furthermore, it can be dried with a tube dryer, drum dryer, flash dryer or the like, and if necessary, pulverized and sieved to obtain a wet corn flour as a dry powder.

  The wet corn flour of the present invention produced in this way has an appropriate corn flavor, and the unique grain odor and taste are greatly removed. Also, since no chemicals are used during immersion, there is no chemical odor or astringency.

  Furthermore, in the wet corn flour of the present invention, the grain structure is softened by immersion as compared with the conventional dry milling dry corn flour, but the protein remains as a tissue around the starch.

That is, below the hot water soluble component is 3% (dry weight basis), with a protein-bound starch content is from 40 to 100% novel compositional specific (configuration). Here, the hot water-soluble component is preferably 1% or less, more preferably 0.7% or less, and the amount of protein-bound starch is preferably 50 to 90%.

  For this reason, there is no rough feeling compared with the conventional dry corn flour, and physical properties such as swelling are improved. For this reason, especially when used for rice crackers or bakery products, it swells well.

  Therefore, the wet corn flour of the present invention can be used as a main ingredient or an auxiliary ingredient of various foods. That is, various foods can be obtained by a conventional production method using the wet corn flour instead of part or all of the raw material of flour such as conventional dry corn flour, wheat flour and rice flour.

  The food to which the wet corn flour of the present invention is applied is not particularly limited. Suitable foods include, for example, fermented foods such as miso and liquor, noodles, rice cakes, rice cakes, confectionery, seasonings, etc., particularly preferably rice crackers, rice confectionery, puffed snacks, fried foods, etc. Bakery products such as puffed foods, breads and cakes.

  In addition, the wet corn flour of the present invention can be used as a raw material, and the contained starch can be hydrolyzed to obtain a saccharified product such as starch syrup. This saccharified product does not have a unique grain odor or taste and has a good corn flavor. The saccharification method can be performed using conventional techniques. For example, it is liquefied, saccharified, filtered and concentrated with acid or enzyme.

  Further, a saccharified product containing a large amount of soluble proteins, peptides and amino acids can be obtained by solubilizing and degrading the protein contained in the wet corn flour with a proteolytic enzyme. As the proteolytic enzyme, various proteases such as acidic, neutral and alkaline peptidases and proteinases can be used alone or in combination. The saccharified product containing a large amount of soluble protein and the like thus obtained is suitable as a raw material for brewing such as beer and happoshu, and as a main raw material and auxiliary raw material for health functional foods.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further more concretely, this invention is not limited to these Examples.

  In addition, each characteristic value of the corn flour of each Example and Comparative Example is measured by the following method.

1) Protein content:
Obtained based on Kjeldahl method.

2) Fat content:
It was determined by ether extraction using a Soxhlet extractor.

3) Hot water soluble component amount:
1L of water at 55 ° C was added to a 200 g sample in terms of dry matter, filtered at 55 ° C for 5 hours with continuous stirring (rotation speed 100 min-1) and filter paper (5 types A (JIS P 3801)). The test liquid was prepared by making the washing liquid 2 L with water. 20 mL of the sample solution was taken in a weighing can and dried at 105 ° C. for 5 hours to obtain the solid content. The said solid content was set to a percentage of the dry matter weight.

4) Protein-bound starch content:
To 200 g of sample crushed to 325 mesh pass with a ball mill (in terms of dry matter weight ), add water to make 1 L, add several drops each of methylene blue staining solution and eosin staining solution, and continuously stir at 30 ° C. for 1 h (rotation speed 100 min-1) Thereafter, 50 mL is collected in a centrifuge tube with a scale, and centrifuged for 15 min (rotation speed 2000 min-1). Then, free protein is separated in the upper layer, free single starch is separated in the lower layer, and protein-bound starch is separated in the intermediate layer. Each volume is visually judged to determine the percentage of intermediate layer-bound starch.
(1) Production of wet corn flour <Example 1>
12 kg of dent corn was immersed in a dipping tank at 60 ° C. for 15 hours while circulating 15 kg of hot water. The pH at this time was 6.3. Next, 36 kg of water was added thereto, coarsely pulverized by an enterator (disc rotating crusher), and then passed through a vibrating sieve equipped with a 60 mesh sieve to remove skin, germ and hard endosperm. Washing was performed by repeating dehydration by a centrifugal dehydrator equipped with a filter cloth and reslurrying by adding 36 kg of water three times. This was dehydrated with a centrifugal dehydrator and dried with a shelf-type dryer at 50 ° C. for 10 hours to obtain 6 kg of wet corn flour. This had a protein content of 7.1% and a fat content of 0.8%. Also, the hot water soluble component is 0.9% (dry weight basis), protein-bound starch content was 75%.

<Example 2>
The same operation as Example 1 was performed except having passed the vibration type sieve provided with the 200 mesh sieve, and 4.5 kg of wet corn flour was obtained. This had a protein content of 5.3% and a fat content of 0.6%. Also, the hot water soluble component is 0.5% (dry weight basis), protein-bound starch content was 65%.

<Example 3>
The same operation as in Example 1 was performed except that the immersion was 63 ° C., 10 hours, and the pH was 5.2, to obtain 5.5 kg of wet corn flour. This had a protein content of 6.2% and a fat content of 0.7%. Moreover, the warm water soluble component was 2.2% (based on dry matter weight), and the ratio of protein-bound starch was 85%.

<Comparative Example 1>
The dry water milled corn flour (commercially available) had a hot water soluble component of 8.5% (based on dry matter weight) and a protein-bound starch ratio of 95%.

<Comparative example 2>
The% protein-bound starch (based on dry matter weight) of the milk starch emulsion prepared by wet milling was 0.5%.
(2) Manufacture of rice crackers
1.6 kg of water was added to 2 kg of each of the wet corn flours of Examples 1 to 3, heated and kneaded with a steamer for 30 minutes, cooled to 65 ° C., rolled and die-cut. This dough was dried with hot air at 75 ° C. for 2 hours. After standing for 10 hours, it was dried with hot air at 75 ° C. for 2 hours. It was baked at 230 ° C. with a plain roaster, seasoned liquid was added, and dried with hot air at 80 ° C. for 2 hours to obtain a rice cracker of the example.
Their degree of swelling and sensory characteristics were evaluated, and the results are shown in Table 1.

<Application control example rice crackers>
The same operation as in the case of using the rice crackers in Examples was carried out except that 2 kg each of glutinous rice flour and dry milled corn flour (Comparative Example 1) was used, and each rice cracker in the Comparative Example was obtained.

<Evaluation method>
Their swelling properties and sensory characteristics were evaluated by the following methods.

    1) Degree of swelling: The volume of the dough was taken as 1, and the volume of the rice cracker after baking was expressed as a ratio. The volume was measured by a glass bead (2 mmφ) replacement method.

    2) Sensory test: It was set as the average value of three-step evaluation by a panel of 10 people.

Score of savory taste, grain odor ... No: 1, there is a little: 2, there is: 3
Flavor rating ... Good: 1, Normal: 2, Bad: 3
As shown in Table 1, the results of the evaluation are shown in Table 1. Examples of rice crackers using the wet corn flour of the present invention have a higher degree of swelling than those of the dry milling wet corn flour of the comparative example, and have a unique grain odor and tingling. The taste was greatly removed and the corn flavor was good.

（３）スポンジケーキの製造
＜実施例のスポンジケーキ＞
実施例１〜３の湿式コーンフラワー各々３０ｇに小麦粉７０ｇを混ぜてミックス粉とする。卵１６０ｇに砂糖２０ｇを加え湯せんにかけて泡立て、冷やした後、さらに泡立てる。これに各々のミックス粉をふるいながら加え、さらに溶かしたバター３０ｇを加えて混ぜる。これを円筒形の型に入れ、オーブンで１８０℃、２５ｍｉｎ焼いて実施例のスポンジケーキを得た。

(3) Production of sponge cake <Sponge cake of Example>
Mix 30g each of wet corn flour of Examples 1-3 with 70g of flour. Bubbled over the eggs 160g sugar 20g added water bath, after cooling, further whipping. Add each mixed powder to this while sieving, then add 30 g of melted butter and mix. This was put into a cylindrical mold and baked in an oven at 180 ° C. for 25 minutes to obtain a sponge cake of the example.

<Comparative sponge cake>
Except for using 30 g each of wheat flour (wheat flour only) and dry milled wet corn flour, the same operation as above was performed to obtain each sponge cake of Comparative Example.

<Evaluation>
1) Degree of swelling: The thickness of the dough was set to 1, and the thickness of the sponge cake after baking was expressed as a ratio.

    2) The sensory test was conducted in the same manner as in the case of the above-mentioned crackers.

  The evaluation results are as shown in Table 2. As shown in Table 2, the example sponge cake using the wet corn flour of the present invention has a higher degree of swelling than that of the dry milled wet corn flour of the comparative example. The savory taste was greatly removed and the corn flavor was good.

（４）糖化製品の製造
実施例２の湿式コーンフラワー１ｋｇに水２．5ｋｇを加えスラリーとした。このｐＨは６．０であった。これに液化酵素（天野エンザイム、アミラーゼＡ）１ｇを加えて、撹拌しながら９０℃まで徐々に昇温し、３０分維持した。６０℃に冷却した後、糖化酵素（天野エンザイム、ビオザイムＭ）２ｇを加えて６０℃で２４ｈ糖化した、さらにタンパク質分解酵素（天野エンザイム、プロテアーゼＳ）２ｇを加えて６０℃で２４ｈ保持した。このものをコットンフィルターでろ過し、Ｂｘ７５％に濃縮して水飴を製造した。

(4) Production of saccharified product To 1 kg of wet corn flour of Example 2, 2.5 kg of water was added to form a slurry. This pH was 6.0. 1 g of liquefied enzyme (Amano Enzyme, Amylase A) was added thereto, and the temperature was gradually raised to 90 ° C. with stirring, and maintained for 30 minutes. After cooling to 60 ° C., 2 g of saccharifying enzyme (Amano Enzyme, Biozyme M) was added for saccharification at 60 ° C. for 24 h, and 2 g of proteolytic enzyme (Amano Enzyme, Protease S) was added and kept at 60 ° C. for 24 h. This was filtered through a cotton filter and concentrated to Bx75% to produce chickenpox.

  This syrup has almost no peculiar grain odor or taste, and has a good corn flavor, protein and amino acid.

It is a process block diagram which shows the manufacturing method of the wet corn flour of this invention.

Claims (9)

1) A warm water soaking step in which corn kernels are soaked in warm water under the condition that starch in the corn kernels is not gelatinized.
2) A crushing step of crushing corn grains after the warm water immersion of 1) above.
3) A purification step of removing the germ and skin of the composition of 2) above, removing 50 mesh-on hard endosperm coarse particles, and further washing.
In addition to each step of
The method for producing wet corn flour, characterized in that the warm water immersion is performed under the conditions of temperature: 55 to 65 ° C. x time: 3 to 30 h by setting the pH to 5 to 7.   2. The method for producing wet corn flour according to claim 1, wherein in the purification step, 150 mesh-on hard endosperm coarse particles are removed. A wet corn flour produced through a warm water soaking process in which corn kernels are soaked in warm water under the condition that starch in the corn kernels is not gelatinized,
Amount of soluble component in hot water at 55 ° C. (hereinafter referred to as “warm water soluble component amount”) 3% (based on dry matter weight) or less, and adding several drops of dyeing solution to an aqueous solution of 200 g (based on dry matter weight) / L A wet corn flour, wherein the volume ratio of protein-bound starch (amount of protein-bound starch) obtained by fractionating the obtained sample as an intermediate separation layer by centrifugation is 65 to 85 vol%. The wet corn flour according to claim 3, wherein the amount of the hot water soluble component is 1% or less. A food comprising the wet corn flour according to claim 3 or 4 as a main ingredient or an auxiliary ingredient. Rice confectionery containing the wet corn flour according to claim 3 or 4 as a main ingredient or an auxiliary ingredient. A bakery product comprising the wet corn flour according to claim 3 or 4 as a main raw material or an auxiliary raw material. A saccharified product, which is a hydrolyzate of a starch raw material containing the wet corn flour according to claim 3 or 4 . The saccharified product according to claim 8 , further comprising a protein hydrolyzate.

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