JP2008228620A - Method for producing shochu (distilled white liquor) using sweet potato - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing the shochu using sweet potatoes, capable of performing baking treatment to obtain the sweet potatoes that turns into a raw material without having oxidation or scorch, and having substantially all parts of alpharized porous state and obtaining the shochu having proper flavor. <P>SOLUTION: The treated sweet potatoes having approximately 40% water content are obtained by washing 3.6 kg of raw sweet potatoes (Kogane sengan), cutting to cubes with skin having 5 mm sides and heat-treating at 250°C for 7 min by a super-heated steam type cooking device. By inoculating koji mold on the obtained treated sweet potatoes and the koji is cultured for 42 hr. Then the sho-chu is prepared by using the malted sweet potato. As to a primary process, water and yeast are added to the malted sweet potato, and a fermentation is performed at 28°C for 6 days. As to a secondary process, the raw material of steamed hot sweet potatoes is added and fermentation is performed at 30°C for 9 days. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a method for producing shochu using sweet potato, and more particularly to a method for producing shochu using pre-gelatinized sweet potato as a koji raw material.

  Conventionally, it is publicly known that a material obtained by granulating sweet potatoes by grinding, dehydrating and steaming is used as a raw material for shochu (see Patent Document 1). Patent Document 2 discloses a method for producing a koji raw material using sweet potato as a main material, which is an improvement of the above method. According to this, the koji raw material is mainly made from koji, which is obtained by granulating by adding rice koji to a frozen koji koji, squeezing juice and grinding. Patent Document 3 discloses a method for producing shochu and food using the roasted potatoes and roasted potatoes obtained by cutting sweet potatoes and roasting them. Furthermore, Patent Document 4 discloses a method for making shochu using a dried potato obtained by washing raw potatoes and then mincing them into mince shapes, then drying them with hot air, and setting them as a cocoon substrate. It is shown.

JP-A-6-113800 JP-A-8-17777 JP 2001-95523 A JP 2002-330749 A

However, the raw material prepared by simply steaming and pulverizing the sweet potato has a problem that not only the glutinous fungi are agglomerated and the gonococci are poorly propagated and easily contaminated with bacteria, but also the enzyme titer is weak.
In the present invention, there was no oxidation / burning of the sweet potato as a raw material, a porous (porosity) roasting treatment in which almost the whole was α-treated, and a sweet potato with a good flavor was used. A method for producing shochu is provided.

  The method for producing shochu according to the present invention that achieves the above object is characterized by using sweet potato roasted with superheated steam as a koji raw material.

  In the present invention, the sweet potato is heated with superheated steam, so that there is no oxidation or scorching, and the whole is made into a porous finish, and a good quality koji can be obtained in the subsequent fermentation process. In addition, shochu made from the koji also has good liquor quality.

  The varieties of sweet potato used in the present invention are not particularly limited, but among them, Koganesengan and Murasakimasari are preferably used. The sweet potato used in the present invention can be raw or preheated (steamed or soaked in warm water), but raw is most suitable.

  The sweet potato used in the present invention is appropriately cut into a size, and then roasted with superheated steam to be alpha. The size of the cut piece is preferably 10 mm or less. In particular, a size of 3 to 7 mm is preferable in view of the subsequent fermentation process. Examples of the cutting shape include a cube, a prism, a pyramid, a trapezoid, a cylinder, a cone, a trapezoid, a sphere, and a wedge. Moreover, you may combine the thing of these shapes. The temperature of the superheated steam is preferably 150 to 400 ° C, more preferably 200 to 300 ° C.

  In the koji-making method of the present invention, koji molds are mixed with sweet potato that has been treated with superheated steam. The moisture content of the sweet potato after the superheated steam treatment is preferably 25 to 50%, more preferably 35 to 45%. The iron making method may be a hand iron making method such as a lid iron or a box iron or a iron making method using a machine such as a rotating drum type or a rotating disk type. Superheated steam-treated sweet potato can be obtained in about 20 to 72 hours at ° C. Moreover, although good rice bran can be obtained without adding a nitrogen source such as rice bran, the addition of a nitrogen source at the time of kneading is optional. The seed pods to be used are not particularly limited, and commonly used Aspergillus fungi (mainly white koji mold, black koji mold, yellow koji mold), spider mold, red koji mold, and the like can be used.

  In the method for producing shochu according to the present invention, the whole preparation method, the one-step preparation, the multi-step preparation, etc. are possible as the preparation method, and the salmon ratio and the pumping water ratio are arbitrary. Also in the distillation method, atmospheric distillation, vacuum distillation, other distillation methods and the like can be used.

  EXAMPLES Hereinafter, although this invention is demonstrated further in detail based on an Example, this invention is not limited to an Example.

  First, the size of the sweet potato cut pieces was examined. Wash the raw sweet potato and cut 300g into 5mm square, 10mm square, and 15mm square cubes with the skin in place, and then take the time required to obtain an appropriate amount of water by superheated steam treatment. It was judged.

  As can be seen from Table 1, in the case of 10 mm square and 15 mm square, the treatment time becomes long to make the moisture content appropriate, and the surface is also burnt. A 5 mm square is optimal in terms of processing time and surface condition.

  Sweet candy koji and superheated koji that were treated with steam under the above conditions were mixed and kneaded. After the koji making, the acidity, moisture, and enzyme titer (α-amylase, acidic prothese, acidic carboxypeptidase) were analyzed. In addition, acidity, moisture, and acid prothesis titer were measured by the 4th revision of the National Tax Agency's prescribed analysis method. Α-amylase and acid carboxypeptidase were measured by α-amylase measurement kit (manufactured by Kikkoman Corporation) and acid carboxypeptidase, respectively. It measured using the kit (made by Kikkoman Corporation). The results are shown in Table 2.

  As can be seen from Table 2, those cut to 10 mm square and 15 mm square have lower acidity and enzyme titer than those cut to 5 mm square, and it is considered that problems occur in the subsequent fermentation process. Although the enzyme titer cut to 5 mm square is lower than that of rice bran, it has sufficient acidity and is not considered to cause problems in the fermentation process. The cutting size of the raw sweet potato was set to 5 mm square from the values shown in Table 7, fermentation suitability, and ease of handling.

  After washing 3.6kg of raw sweet potato (koganesengan), it is cut into a 5mm square cube with the skin attached, and then heated at 250 ° C for 7 minutes using a superheated steam cooker (Super Oven: manufactured by Kiyomoto Seiko Co., Ltd.) Heat treatment was performed to obtain a treated sweet potato with a water content of about 40%. It can be seen that the processed sweet potato is hard on the outside, soft on the inside, yellowed in appearance, and is well progressed to alpha.

  Next, this superheated steam-treated sweet potato was inoculated with seed pods (Kawachi NK fungus) and koji made for 42 hours. The obtained sweet potato was good as a candy with good handling and breakage. The water content of sweet potato and the acidity after koji making were measured. Moisture and acidity were measured according to the 4th revision of the NTA's prescribed analytical comment. The analysis results are shown in Table 3.

  As can be seen from Table 3, the sweet potato of this example has an acidity equivalent to that of commonly used rice bran, and it can be said that there is no problem in the next fermentation process.

  Next, shochu was produced using this sweet potato. For primary charging, water and yeast were added to sweet potato and fermentation was performed at 28 ° C. for 6 days. For secondary charging, steamed sweet potato material was added and fermentation was performed at 30 ° C. for 9 days. Table 4 shows the preparation of shochu and Table 5 shows the analysis results of the moromi before distillation. In addition, alcohol, acidity, volatile acidity, sake degree, and amino acid degree were measured according to the 4th revised National Tax Agency prescribed analysis comment.

  As can be seen from Table 3, the sweet potato of this example has a slightly lower alcohol value than the mash made from rice bran candy, but it is sufficiently fermented and has no problem in terms of acidity and volatile acidity. It can be said. Table 6 shows the results of atmospheric distillation of the moromi after fermentation.

  A sensory test was conducted on shochu obtained by dividing the obtained distillate into 25% alcohol. The sensory test was conducted by 14 panelists, and the average of the panelists according to the three-point method (the score is obtained by dividing the total score by the three-point method by the number of panelists, and the smaller number obtained the better evaluation). Evaluated by value and comment. The results of the sensory test are shown in Table 7.

  As shown in the sensory test of Table 7, the shochu liquor of this example had many evaluations such as sweet, fruity and gorgeous, and obtained high evaluation that both taste and aroma were good.

[Comparative example]
An example in which sweet potato (koganesengan) is treated with superheated steam is compared with one that has been hot-air dried.
As the hot-air dried sweet potato used, 3.6 kg of raw sweet potato was cut into a 5 mm square cube and dried with hot air at 250 ° C. for 4 minutes to obtain a dried sweet potato with a water content of about 40%. The hot air dried sweet potato was hard on the outside and soft on the inside, but unlike the superheated steam-treated one, the starch on the surface was not promoted to be gelatinized due to a decrease in moisture. In order to confirm the difference between the sweet potato treated with superheated steam and the sweet candy dried with hot air, the cross section was observed with a scanning electron microscope. The photograph is shown in FIG.1 and FIG.2.

  As can be seen from FIG. 1, in the superheated steam treatment, it can be observed that the starch granules in the starch sac are α-formated and dissolved not only in the sweet potato but also in the surface layer. On the other hand, in the hot air drying treatment, as can be seen from FIG. 2, it can be observed that the starch grains remain on the surface layer and the starch grains are dissolved only inside. This is because in the superheated steam treatment, the moisture on the surface increases due to condensation, and the temperature immediately becomes around 100 ° C. Therefore, it is considered that the entire sample including the surface layer satisfies the pregelatinization condition of starch. On the other hand, in the hot-air drying process, the temperature rise is slow, and moisture necessary for the pregelatinization evaporates before the temperature reaches the pregelatinization condition. Therefore, it is considered that starch granules remain on the surface layer.

  Next, using the superheated steam-treated sweet potato of the example and the hot-air-treated sweet potato of the comparative example, seed potato was inoculated and koji was made for 42 hours. The obtained sweet potato was not sticky or out of shape, and it was easy to handle and break. Table 8 shows the analysis results of Examples and Comparative Examples. Moisture and acidity were measured according to the 4th revision of the NTA-specified analysis method.

  As can be seen from Table 8, in terms of acidity and water content, the koji with no problem in the subsequent fermentation was obtained in both Examples and Comparative Examples.

  Next, shochu was produced using the superheated steam-treated sweet potato of the example and the hot-air dried sweet candy of the comparative example. For secondary charging, steamed sweet potato (koganesengan) hanging raw material was added and fermentation was performed at 30 ° C. for 9 days. Table 9 shows the blended composition of shochu and Table 10 shows the analysis results of the moromi before distillation. Alcohol, acidity, volatile acidity, sake content, amino acid content, reducing sugar, and total sugar content were measured according to the 4th revision of the NTA-specified analytical method.

  As can be seen from Table 10, the alcohol content before distillation was higher in the example than in the comparative example, and the fermentation state was good. Further, the total sugar content is about twice as high in the comparative example as in the example. This is due to the fact that the gelatinization did not proceed well in the hot air drying treatment, and the raw starch remained on the surface of the sweet potato.

  Table 11 shows the results of atmospheric distillation of the moromi after fermentation.

  As can be seen from Table 11, the example showed higher values in yield, distillation rate, and fermentation rate than the comparative example.

  Shochu liquor was obtained by splitting the obtained distillate into 25% alcohol. The dominant sake was evaluated by a three-point method and comments by 14 panelists. The results are shown in Table 12.

  As a result of dominant sake, there were as many as 8 panelists who preferred the example, and the evaluation was also high in the three-point method. It was an evaluation that the taste and fragrance were both good shochu, and in both cases, it exceeded the comparative example.

Scanning electron micrograph showing a cross-section of sweet potato treated with superheated steam. The scanning electron micrograph which shows the cross section of the sweet potato which carried out the hot air drying process.

Claims (1)

A method for producing shochu, characterized by using sweet potato roasted with superheated steam as a koji raw material.