Fermented and dried tofu production method

Abstract

To provide a method for producing fermented and dried tofu flakes, capable of producing tofu flakes containing a larger amount of soup stock components from soybean protein in tofu. Tofu is dehydrated under pressure while being cooled for 10 to 15 hours, and then soaked in 5% salt water for 10 to 15 hours while being cooled. Next, the tofu is soaked in rice koji to break down the tofu's proteins, and the tofu is molded in a primary mold-growing process in which rice koji is allowed to grow deep within the tofu, and a secondary mold-growing process in which koji mold, used to make bonito flakes, is grown, and the tofu is then finished and dried.

Description

[Technical Field]

[0001] The present invention relates to a method for producing fermented and dried tofu flakes that can produce tofu flakes containing a larger amount of dashi components from the soybean protein in tofu, and is a method for producing fermented and dried tofu flakes that is suitable for producing dashi soup stock for Buddhist vegetarian cuisine. [Background technology]

[0002] In relation to Buddhist teachings, cuisine that does not use animal-based broth has long been known as shojin ryori. The broth used in shojin ryori was typically made from kelp and shiitake mushrooms. Furthermore, during the Heian period, it became possible to make dried tofu by coating tofu with salt and drying it, and this dried tofu was thinly sliced ​​and used in shojin ryori and other dishes as a supplement to the broth.

[0003] This dried tofu is called shojinbushi or rokujo tofu, and the rokujo tofu made by Tofu Kobo Seiryuan in Sagae City, Yamagata Prefecture is still used in some shojin cuisine today. However, because this rokujo tofu is made by directly coating salt on dehydrated tofu and then drying it, the high salt concentration means that the protein in the tofu is not fully utilized in the dashi, and the umami flavor of the soy protein cannot be fully brought out.

[0004] Meanwhile, the following Patent Document 1 is known as prior art related to dried tofu. This Patent Document 1 provides lactic acid fermented tofu obtained by fermenting Okinawan island tofu using plant-derived lactic acid bacteria. The technology described involves applying moderate pressure to the Okinawan island tofu to squeeze out the water contained therein, adding lactic acid bacteria to the tofu in a marinade prepared using miso, mirin, sugar, a small amount of sake, etc., and fermenting the tofu for a certain period of time to impart a unique flavor, texture, and functionality. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2009-296947 A Summary of the Invention [Problem to be solved by the invention]

[0006] The above-mentioned Patent Document 1 discloses a technology for producing dried tofu. However, this dried tofu was made by fermenting tofu by soaking it in red koji or awamori, and was a type of "tofuyo" unique to the Ryukyu region, so it was unable to bring out the umami flavor of soy protein.

[0007] In response to this, there was a demand for a dashi stock used in shojin ryori that could be used not only as an ingredient in shojin ryori, but also as a seasoning ingredient for people who do not consume animal-based dashi stock or who avoid the use of umami seasonings. For this reason, it was necessary to develop a shojin broth made from tofu that contains more dashi components from the soy protein in tofu.

[0008] The present invention has been made in view of the above-mentioned background, and an object of the present invention is to provide a method for producing fermented and dried tofu flakes that can produce tofu flakes containing a larger amount of dashi components from the soybean protein in tofu. [Means for solving the problem]

[0009] The invention described in claim 1 that solves the above problem is a method for soaking tofu in salt water, Next, the tofu is soaked in rice koji to break down the protein in the tofu, and then the tofu is molded. However, there is a primary mold-making process in which rice koji is grown deep inside the tofu, and a secondary mold-making process in which Eurotium herbarium, the koji mold used to make bonito flakes, is grown. Then, finish drying The moisture content is set to 5% or less. This is a method for producing fermented and dried tofu flakes.

[0010] According to the method for producing fermented and dried tofu as claimed in claim 1, the salt concentration can be kept low because the tofu is simply soaked in salt water. Furthermore, the tofu is soaked in rice koji to break down the tofu's proteins, and then mold is grown on the tofu, followed by finishing drying, resulting in fermented and dried tofu that is as hard as bonito flakes.

[0011] As a result, this manufacturing method can break down the soy protein in tofu into peptides and amino acids, which are the source of nutrition and flavor, making it possible to produce firm fermented dried tofu flakes that contain more dashi components.In other words, this fermented dried tofu flakes can produce dashi that can be used not only as an ingredient in shojin cuisine, but also as a suitable seasoning ingredient for people who do not consume animal-based dashi or who avoid the use of umami seasonings. On the other hand, according to this claim, when the tofu is molded after being soaked in rice koji, there is a primary mold-growing process in which rice koji is allowed to grow deep inside the tofu, and a secondary mold-growing process in which koji mold used to make bonito flakes is grown. Soaking tofu in rice koji breaks down the soy protein on the surface of the tofu, but to make tofu dashi, further mold-making is required. For this reason, a primary mold-making process is carried out because mold breaks down the soy protein deeper in the tofu, and because rice koji requires moisture to grow on the tofu, it is expected to play an auxiliary role in removing moisture from the deeper parts. Furthermore, in the secondary mold-growing process, koji mold, which is used to make dried bonito flakes, is grown on the fat contained in the dehumidified tofu, which promotes the decomposition of soybean protein and refines the flavor. Furthermore, since the koji mold requires moisture when growing, it can further remove moisture from deep within the tofu, making the tofu as hard as dried bonito flakes.

[0012] According to the method for producing fermented and dried tofu as set forth in claim 2, the tofu is dehydrated before being soaked in salt water, which actively removes moisture from the tofu and allows it to effectively absorb salt water when soaked in salt water. According to the method for producing fermented and dried tofu as set forth in claim 3, when dehydrating the tofu, the tofu is dehydrated under pressure while being cooled for 10 to 15 hours, which removes most of the moisture from the tofu and allows it to absorb an appropriate amount of salt water when it is subsequently soaked in salt water.

[0013] According to the method for producing fermented and dried tofu as set forth in claim 4, the tofu is soaked in 5% salt water for 10 to 15 hours while being cooled during the soaking process, which effectively promotes the decomposition of soy protein in the tofu and prevents the tofu from spoiling due to mold growth on the tofu. [Effects of the Invention]

[0017] As described above, the present invention has the excellent effect of providing a method for producing fermented and dried tofu flakes that can produce tofu flakes containing a larger amount of dashi components from the soybean protein in tofu. [Brief explanation of the drawings]

[0018] [Figure 1] FIG. 1 is a diagram showing a production process chart for fermented and dried tofu flakes according to one embodiment of the present invention. [Figure 2] FIG. 1 is a diagram showing tofu in a first step according to an embodiment of the present invention. [Figure 3] FIG. 2 is a diagram showing a state in which a weight is placed on tofu in the first step according to one embodiment of the present invention. [Figure 4] FIG. 2 is a diagram showing soaking of tofu in salt water in a second step according to one embodiment of the present invention. [Figure 5] FIG. 10 is a diagram showing the soaking of tofu in rice koji in the third step according to one embodiment of the present invention. [Figure 6] FIG. 10 is a diagram showing primary mold growth on tofu in the fourth step according to one embodiment of the present invention. [Figure 7] FIG. 10 is a diagram showing the state after the primary mold growth on tofu is completed in the fourth step according to one embodiment of the present invention. [Figure 8] FIG. 10 is a diagram showing the state after secondary mold-grown tofu has been completed in the fifth step according to one embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0019] Hereinafter, one embodiment of the method for producing fermented dried tofu according to the present invention will be described in detail with reference to the accompanying drawings. The present embodiment aims to produce fermented and dried tofu flakes that are as hard as bonito flakes and can be used not only as an ingredient in vegetarian cuisine but also as a seasoning ingredient for people who do not consume animal-derived soup stock or who avoid the use of umami seasonings.

[0020] Tofu to be fermented and dried in the method for producing fermented and dried tofu flakes according to this embodiment is first prepared in advance, such as commercially available firm tofu that contains a high proportion of soybeans. The reason firm tofu is used here is that typically 77 to 90 g of soybeans are required to produce one block of firm tofu, and due to the method for producing firm tofu, it has a low water content and a high soybean (soy milk) content, making it suitable for producing tofu flakes. In contrast, filled tofu, like firm tofu, is made by mixing soy milk with bittern and then filling the mixture directly into a container. Therefore, it has a high water content, is smooth, and soft, and is not optimal for producing tofu flakes, but it can still be used.

[0021] Tofu flakes are produced according to the steps shown in the production flow chart in Figure 1, and the first step is to dehydrate the tofu. The purpose of dehydrating the tofu is to remove as much water as possible from the tofu, which will accelerate the breakdown of soybean protein in the tofu in the next process and promote the absorption of salt water to prevent spoilage.

[0022] Specifically, ten blocks of tofu 10 are arranged on a dehydration tray 12 with drainage holes in the bottom, as shown in FIG. 2, and a plate or other material is placed on top of the tofu. Then, a 2-3 kg weight 14, such as a stone weight, is placed on top of the plate as shown in FIG. 3. The tofu 10 is dehydrated for, for example, 12 hours at a temperature of 5-8°C in a refrigerator while applying pressure. The dehydration time may be between 10 and 15 hours. While the number of tofu 10 can be varied depending on the size of the dehydration tray 12, the pressure for dehydration is generally 200-300 g per block. The dehydration method is not limited to the one described above, but the stone weight cannot be too heavy during dehydration because it may crush the tofu 10.

[0023] The second step is a step of soaking the tofu 10 in salt water SW. The purpose of soaking the tofu 10 in salt water SW is to promote the decomposition of the proteins in the tofu 10 and to prevent the tofu 10 from spoiling when mold grows on the tofu 10. Specifically, the 10 blocks of tofu 10 that have been dehydrated in the refrigerator for 10 to 15 hours in the first step are removed from the dehydration trays 12, and then transferred to soaking trays 16 containing 5% salt water SW as shown in Figure 4. The tofu 10 in the soaking trays 16 is then soaked again in the refrigerator for 10 to 15 hours. However, the time may be changed depending on the dehydration conditions.

[0024] The third step is to soak the tofu 10 in rice koji. The salted tofu 10 from the second step is removed from the refrigerator, and the ten blocks of tofu 10 shown in Figure 5 are placed in 1 liter of 0.5% salt water mixed with 200 g of rice koji (soy sauce koji or miso koji) with strong protease activity that has been prepared in advance. The tofu 10 is then soaked for 2 to 5 hours at room temperature of 25 to 30°C in mixed liquid ML, which is salt water containing the enzymes produced by the rice koji, with stirring, to allow the tofu 10 to become coated with the mixed liquid ML.

[0025] However, it is considered more optimal to soak the tofu at room temperature for 3 to 4 hours. On the other hand, if the tofu is soaked for more than 5 hours, the soy protein in the tofu 10 will be decomposed too much, which may affect the taste and tend to make the finished product more bitter.

[0026] In other words, this process aims to break down the soy protein in the tofu 10, from peptides to amino acids, which are the source of nutrition and flavor. The rice koji used here is made using Aspergillus oryzae, a soy sauce koji mold or miso koji mold. Rice koji with strong amylase activity is not used here. Furthermore, in order to break down the soy protein in the tofu 10, the tofu is soaked in salt water in the second process, which makes it less likely to spoil. While soy sauce koji is usually made with barley koji, we use our own rice koji due to allergy labeling requirements, but rice koji can also be purchased from an outside source.

[0027] The fourth step is a primary mold-infusing step for the tofu 10. Although the soy protein on the surface of the tofu 10 is broken down by the third process, moisture remains deep inside, and it is not dried like bonito flakes and cannot be used as dashi. To make dashi, not only is it necessary to further break down the soy protein in the deeper parts of the tofu 10, but since rice koji requires moisture to grow on the tofu 10, mold is added, which is expected to play an auxiliary role in removing moisture from the deeper parts.

[0028] Specifically, the 10 blocks of tofu 10 that have completed the third process are removed from the salt water SW and placed in a special basket 18. At this time, the tofu 10 is sprinkled with rice koji KM as shown in Figure 6 to ensure that the rice koji KM adheres firmly to the tofu 10 and promotes its propagation. The special basket 18 with the tofu 10 lined up is then placed in a dehumidifying dryer where dehumidification culture is carried out, cultivating the koji bacteria on the tofu 10 while dehumidifying under the following conditions. During this dehumidification culture, the tofu 10 is turned over every 12 hours. Dehumidifier temperature setting: 30-40℃ Dehumidified culture time 24~72 hours Furthermore, after the dehumidifying culture is completed, the tofu 10 on which the rice koji KM has grown is removed from the dehumidifying dryer as shown in Figure 7, and the rice koji KM is removed from the surface of the tofu 10. The temperature of the dehumidifying dryer is set to 30 to 40°C, but the maximum temperature is 50°C because this also serves to incubate mold.

[0029] The fifth step is the secondary molding step. The purpose of this process is to give the tofu 10, which has been first molded and dehumidified in the fourth process, a firmness similar to that of dried bonito flakes. In this fifth process, koji mold (KK), used for making dried bonito flakes, is grown on the fat contained in the tofu 10, promoting the decomposition of soy protein and refining the flavor. Furthermore, since koji mold requires moisture for growth, the moisture in the depths can be further removed, resulting in the tofu 10 having a firmness similar to that of dried bonito flakes.

[0030] Specifically, the tofu 10 from the fourth step is again soaked for 5 to 20 minutes in a 0.5% salt solution mixed with rice koji (rice koji) prepared in advance, or is soaked or sprayed for 5 to 20 minutes in water containing dissolved koji starter (seed koji) for the rice koji. The koji mold used here is Aspergillus glaucus or repens, developed in-house and cultivated on rice koji. If Katsuo Aspergillus is sprayed, Eurotium herbariorum is used. The basket containing the tofu 10 is then placed back into the dehumidifying dryer, where the tofu 10 is dehumidified and cultured under the following conditions to grow mold. During this dehumidifying culture, the tofu 10 is turned over every 12 hours.

[0031] Dehumidifier temperature setting: 30-40℃ Dehumidified culture time 12~36 hours As a result of the above, when the dried bonito fungus grows on the surface of the tofu 10 as shown in Figure 8, the dehumidifying culture is terminated. After the dehumidifying culture is completed, the tofu 10 is removed from the dehumidifying dryer, and the Aspergillus oryzae KK that has grown on the surface of the tofu 10 is removed. Note that this secondary mold-incubation step is not necessarily required, and the tofu may be completed after the fourth step, but completing this fifth step will result in higher quality dried tofu.

[0032] The sixth step is the finishing drying step. In order to improve the shelf life of the tofu flakes that are almost completed through the fourth or fifth step, the moisture content is reduced to 5% or less and drying is carried out to sterilize the surface of the tofu flakes. Specifically, the tofu flakes that have been mold-dried and mold-removed in these processes are placed on a drying tray and dried in a hot air dryer at 75°C for 1 to 10 hours, but the specific drying time is determined by the results of measuring the moisture content up to the previous process.

[0033] The seventh step is the finishing step. This process involves cooling the tofu flakes that have been finished and dried in the sixth process, and then packaging them into products. These tofu flakes are then transported to retail stores or mailed to consumers who have placed orders online.

[0034] Examples of uses for the "fermented dried tofu" produced according to this embodiment include the following. First, by thinly slicing "fermented dried tofu flakes" and adding them to other ingredients such as kelp, shiitake mushrooms, and vegetables when making dashi, you can create a richly flavored dashi. Also, by finely crushing "fermented dried tofu flakes" and mixing them into salad dressing, you can create a flavorful dressing. Furthermore, by coarsely crushing "fermented dried tofu flakes" and putting it in a dashi bag, you can create a single-use dashi bag.

[0035] As described above, the method for producing fermented and dried tofu flakes according to this embodiment allows the soy protein in tofu to be broken down into amino acid or peptide units that are the source of umami, thereby enabling the development of fermented and dried tofu flakes (also called tofu flakes or vegetarian flakes) that contain a greater amount of dashi components. Therefore, the produced fermented and dried tofu flakes can be used not only as an ingredient in vegetarian cuisine, but also as a seasoning for people who do not consume animal-based dashi or who avoid the use of umami seasonings. Accordingly, by shaving this fermented and dried tofu flakes like bonito flakes and adding them to dashi, it is possible to create dashi for vegetarian cuisine that does not use animal ingredients.

[0036] In the above embodiment, fermented and dried tofu was produced in batches of 10 blocks of tofu, but this is merely an example and batches of 20 or more blocks may be produced. Also, in the second step, 10 blocks of tofu were transferred to the soaking tray 16 containing 5% salt water SW, but salt water SW with a concentration of 5 to 20% may also be used.

[0037] Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications are possible based on the spirit of the present invention, and these are not excluded from the scope of the present invention. [Industrial Applicability]

[0038] The method for producing fermented and dried tofu flakes according to the present invention relates to a method for producing tofu flakes containing a larger amount of dashi components from the soybean protein in tofu, and is intended for producing dashi stock for Buddhist vegetarian cuisine, but can also be applied to ordinary cooking dashi stock other than dashi stock for Buddhist vegetarian cuisine. [Explanation of symbols]

[0039] 10 Tofu 12 Dehydration tray 14 weights 16 Pickling tray 18 Dedicated basket KK Aspergillus oryzae KM rice koji ML mixture SW Saltwater

Claims

1. Soak the tofu in salt water, Next, the tofu is soaked in rice koji to break down the proteins in the tofu, and then the tofu is molded. This involves a primary mold-growing process in which rice koji is allowed to grow deep inside the tofu, and a secondary mold-growing process in which Eurotium herbarium, the koji mold used to make bonito flakes, is grown. This is the manufacturing method for fermented and dried tofu flakes, which are then subjected to finishing drying to reduce the moisture content to 5% or less.

2. 2. The method for producing fermented and dried tofu flakes according to claim 1, wherein the tofu is dehydrated before being soaked in salt water.

3. 3. The method for producing fermented and dried tofu according to claim 2, wherein the tofu is dehydrated under pressure while being cooled for 10 to 15 hours.

4. 2. The method for producing fermented and dried tofu according to claim 1, wherein the tofu is soaked in 5% salt water for 10 to 15 hours while being cooled during the soaking step of the tofu in salt water.

Images