JP4457064B2 - Quality improvement method of low amylo flour - Google Patents

Description

  The present invention relates to a method for improving the quality of low amylo flour.

  Wheat contains various enzymes such as amylase, and if amylase activity in wheat occurs when it becomes germinated or close to it due to rain damage during the harvest season of wheat, lack of dryness after harvest or poor storage condition, etc. Abnormally higher than healthy wheat grains. Wheat flour obtained from wheat having such high amylase activity is usually referred to as “low amylo wheat flour”, and is remarkably inferior in secondary processing, and is substantially not edible in many cases.

  “Amylo” of low amylo flour is the maximum viscosity value measured by amylograph tester (manufactured by Brabender, West Germany), ie, amylo viscosity (unit BU; Brabender unit). ).

  Generally, those having an amylo viscosity of 300 B.U. or higher can be said to be normal flour, and flours of less than 300 B.U. may have some problem, especially 250 B.U. Less than low amylo flour is not normal flour. For example, when wheat flour having an amylo viscosity of less than 300 B.U. is used in the manufacture of breads, the mixing resistance of the dough is inferior, the dough becomes sticky and the workability is inferior. In this case, even a slight decrease in workability can be a serious problem. In addition, when low amylo wheat flour having an amylo viscosity of less than 250 B.U. is used, not only the workability but also the quality of the breads obtained is problematic.

  Conventionally, as a method for improving the quality of low-amylo flour, methods of heating wheat grains with hot air or radiant heat for about 2 minutes to several hours and methods of directly treating wheat grains with live steam for several minutes have been attempted. In this method, the amylo viscosity is improved to some extent by deactivation of the enzyme, but at the same time, the protein (gluten) in the flour is denatured, and as a result, only the original properties of the flour are impaired. It was. As an improved method, a method of irradiating a specific amount of microwaves to wheat grains has been proposed (see Patent Document 1), but it is difficult to process in large quantities on an actual production line, and is expensive in terms of equipment. Met.

Japanese Patent No. 2756332

  The objective of this invention is providing the quality improvement method of the low amylo wheat flour which can improve the quality of low amylo wheat flour easily, without impairing the original property of wheat flour.

  The present inventors variously examined low heat treatment to such an extent that the inherent properties of the flour are not impaired without causing the protein (gluten) denaturation in the flour while inactivating the enzyme in the low amylo flour. As a result, it was found that the specific hydration heat treatment of the low amylo flour improves the amylo viscosity of the flour and achieves the above-mentioned purpose.

  This invention is made | formed based on the said knowledge, and provides the quality improvement method of the low amylo wheat flour characterized by carrying out the wet heat treatment of the low amylo wheat flour at the product temperature of 82-97 degreeC for 5 to 60 seconds. is there.

  The wheat flour obtained by the method of the present invention has improved amylo viscosity without impairing the original properties of wheat flour, improved properties of low amylo, and good secondary processability.

The present invention is suitably used for low amylo flour having an amylo viscosity of less than 300 B.U., particularly low amylo flour of less than 250 B.U.
In the present invention, the low amylo flour is subjected to a heat treatment under conditions such that only the enzyme activity in the flour is deactivated without substantially denaturing the starch and protein (gluten) in the flour. Is important, and the effect of the present invention cannot be obtained if the heat treatment is excessive.

  In the present invention, the low amylo flour is subjected to wet heat treatment at an article temperature of 82 to 97 ° C, preferably an article temperature of 86 to 89 ° C for 5 to 60 seconds, preferably 10 to 30 seconds, more preferably 10 to 15 seconds. To do.

  The wet heat treatment is preferably performed in a closed container into which saturated water vapor has been introduced. As a preferable example of such a closed container, a “powder sterilizer” described in Japanese Patent No. 2784505 is described. Is mentioned.

  The wet heat treatment is performed so that the heat-gelatinization ratio of the wet heat-treated wheat flour (the wheat flour heat-heated by the method of the present invention) is preferably 80 to 99, more preferably 90 to 98, and particularly preferably 95 to 97. It is preferable.

The gelatinization heat ratio is measured by the following method.
[Measurement method of heat ratio of gelatinization]
Using a differential scanning calorimeter (manufactured by Seiko Co., Ltd.), an aluminum capsule to which 4 times the amount of distilled water was added to the dry matter amount of wet heat-treated flour and an aluminum capsule to which only the same amount of distilled water was added were used as comparative controls. The temperature is raised from 25 ° C. to 140 ° C. at 5 ° C. per minute, and the difference in endothermic energy from the control is measured. The endothermic energy (peak formed between 30 ° C. and 100 ° C.) generated when gelatinized is expressed as the heat of gelatinization per gram of dry matter (J / g). The heat of gelatinization thus obtained is expressed as a ratio to the heat of gelatinization of untreated wheat flour, and this is defined as the ratio of heat of gelatinization.

  The flour whose quality has been improved by the method of the present invention has an improved property of low amylo and can be used in the same manner as normal flour.

  Next, examples are given to describe the present invention more specifically, but the present invention is not limited to the following examples.

Example 1
Milled raw material mainly from American strong wheat (brand: dark northern spring, crude protein 14.2% by mass), second grade flour with amylo viscosity of 230 B.U. (ash content 0.52% by mass, crude protein 13.2%). 3% by mass) was collected. This was used as a sample of Comparative Example 1.
A sample of Example 1 was obtained by subjecting this sample to wet heat treatment for 10 seconds at an article temperature of 87 ° C. using the same apparatus described in Japanese Patent No. 2784505, and drying and pulverizing the sample.

  The analytical values of the samples of Example 1 and Comparative Example 1 are as shown in Table 1, and the amylo viscosity of the sample of Example 1 was remarkably improved.

Test Examples 1 and 2
Using the samples of Example 1 and Comparative Example 1 described above as flour, roll breads were obtained by the following bread making process and bread making process.
First, as a medium seed process, 70 parts by weight of flour, 2 parts by weight of yeast, 0.1 part by weight of yeast food and 40 parts by weight of water are added and mixed for 2 minutes at low speed and 2 minutes at medium speed to make a medium seed dough. (Kneading temperature 24.0 ° C.) The seed fermentation was performed for 4 hours. Next, as the main meal process, 30 parts by weight of flour, 1.8 parts by weight of salt, 12 parts by weight of sugar, 3 parts by weight of skim milk powder and water are appropriately added to the fermented medium seed dough (described in Table 2). In addition, after mixing for 3 minutes at low speed, 4 minutes at medium speed, and 1 minute at high speed, 8 parts by weight of shortening was added, and then kneaded for 5 minutes at medium speed and 2 minutes at high speed to obtain a main body dough (捏) Raised temperature 27.0 ° C).
The obtained honsen dough was fermented at room temperature for 20 minutes, then divided into 45 g pieces, and then bench time was taken for 20 minutes. Next, this dough was formed into a roll, and after 60 minutes proofing was performed at a temperature of 38 ° C. and a humidity of 85%, it was baked for 9 minutes at a temperature of 210 ° C. to obtain a roll pan.
Each obtained bread roll was evaluated by 10 panelists according to the evaluation criteria shown in Table 3. Table 2 shows the evaluation results (average score of evaluation scores of 10 panelists). Further, the volume of each roll obtained was also shown in Table 2.
As is apparent from the results shown in Table 2, the roll of Test Example 2 obtained using the sample of Example 1 had an excellent quality equivalent to that obtained using normal wheat flour. . On the other hand, in Test Example 1 using the sample of Comparative Example 1, a quality equivalent to that of a normal roll was obtained, but there was a problem in mixing resistance and workability when dividing the dough.

Example 2
Milled raw material mainly composed of strong wheat from America (brand: dark northern spring, crude protein 14.1% by mass), second grade flour with an amylo viscosity of 180 B.U. (0.54 mass% ash, 13. 4% by mass) was collected. This was used as the sample of Comparative Example 2.
A sample of Example 2 was obtained by subjecting this sample to wet heat treatment for 10 seconds at a product temperature of 88 ° C. using the same apparatus as described in Japanese Patent No. 2784505, and drying and pulverizing the sample.

  The analytical values of the samples of Example 2 and Comparative Example 2 are as shown in Table 4, and the amylo viscosity of the sample of Example 2 was remarkably improved.

Test Examples 3 and 4
Using the samples of Example 2 and Comparative Example 2 described above as flour, roll breads were obtained by processing in the same bread-making recipe and bread-making process as in Test Examples 1 and 2.
Each roll obtained was evaluated in the same manner as in Test Examples 1 and 2. Table 5 shows the evaluation results and the volume of each roll.

As is apparent from the results shown in Table 5, the roll of Test Example 4 obtained using the sample of Example 2 had excellent quality equivalent to that obtained using normal wheat flour. . In contrast, the roll of Test Example 3 obtained using the sample of Comparative Example 2 has a main water absorption of 23% (total bread absorption of 63%), which is 3% lower than that of Test Example 4. It can be seen that the secondary processability (mixing resistance, bread dough workability, bread inner phase, bread texture, bread taste / fragrance, bread volume) is inferior. When the main water absorption of Test Example 3 is the same as that of Test Example 4, the secondary workability is further inferior.

Claims (3)

  A method for improving the quality of low amylo flour, characterized by subjecting low amylo flour to wet heat treatment at a product temperature of 82 to 97 ° C for 5 to 60 seconds.   The method for improving the quality of low-amylo wheat flour according to claim 1, wherein the wet heat treatment is carried out in a closed container into which saturated water vapor has been introduced. The quality improvement method of the low amylo wheat flour of Claim 1 or 2 which performs wet heat treatment so that the gelatinization heat ratio of the low amylo wheat flour wet-heat-treated may be 80-99.