Miki (traditional fermented drink) with low viscosity and method for producing the same

Abstract

To provide a method for producing Miki with low viscosity that is smooth and sensory when drunk, has a low adhesive residue on a container and can suppress an increase in the viscosity even when pasteurized.SOLUTION: A method for producing Miki with low viscosity includes using sweet potato, which has high α-amylase activity, as a raw material.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a low-viscosity mix and a method for producing the same. [Background technology]

[0002] Miki is a traditional fermented drink made in places such as Amami Oshima in Kagoshima Prefecture. It is made primarily from rice, sweet potato, and sugar, and the rice starch is converted into sugar by enzymes derived from sweet potato, and lactic acid fermentation by lactic acid bacteria progresses, resulting in a sweet and sour taste. It is attracting attention as a health drink that is not only highly nutritious, but also has the potential for probiotic effects from the lactic acid bacteria (Non-Patent Document 1). [Prior art documents] [Non-patent literature]

[0003] [Non-Patent Document 1] Hiromi Kuru, Naonori Tamaki, Koji Wada, and Kiyoshi Ito. Journal of the Brewing Society of Japan, 2010, 105, 741-748. [Non-Patent Document 2] Hiromi Kuru, Yumiko Yoshizaki, Naonori Tamaki, Koji Wada, and Kiyoshi Ito. Journal of the Brewing Society of Japan, 2010, 105, 167-174. [Non-Patent Document 3] Yoshiyuki Nakamura, Toshikazu Kuranouchi, Akiko Takada, Kenji Katayama. Journal of the Japanese Society for Food Science and Technology, 61(12), 577-585, 2014 Summary of the Invention [Problem to be solved by the invention]

[0004] Conventional miki has the characteristic that the starch derived from rice is not fully saccharified, resulting in high viscosity. This has the advantage of making it feel voluminous when drunk and keeping you full for a long time, but it has issues in terms of ease of drinking and smoothness, and there is also the issue that it is prone to leaving residue on the container. Another issue is that when miki is heat sterilized, the viscosity can increase even further.

[0005] If drinking comfort was a priority, it was possible to reduce viscosity by increasing the water content, but this would reduce the nutritional value and richness of flavor, so there was a demand for mixi with a high solids content and low viscosity. [Means for solving the problem]

[0006] The inventors conducted extensive research to solve the above-mentioned problems and produce a mix that has an excellent drinking experience and prevents an increase in viscosity even when heated.As a result, they discovered that the above-mentioned problems could be solved by using sweet potatoes with increased alpha-amylase activity, and thus completed the present invention. Effect of the Invention

[0007] The present invention has made it possible to produce a mix that has a lower viscosity than conventional products. The mix is ​​smooth and has an excellent sensory quality as a beverage, and the amount of mix that adheres to the container can be reduced. It is also possible to suppress an increase in viscosity even when pasteurized. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 shows the results of a sensory evaluation of the mix of the product of the present invention and the control product. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] The present invention relates to a mix having a moisture content of 75% or less and a viscosity of 300 mPA·s or less, measured at 22° C. and 30 rpm using a Brookfield viscometer.

[0010] In this invention, "miki" refers to a brewed food made using at least rice and sweet potato as ingredients, by mixing the rice and sweet potato heated to a porridge-like consistency and fermenting it at 15 to 40 degrees Celsius for 1 to 3 days.

[0011] The moisture content in this invention refers to a value measured by a normal pressure heat drying method. Specifically, the measurement target mix is ​​heat dried at 110°C for 5 hours, [(Weight before heat drying (g)) - (Weight after heat drying (g)] ÷ (Weight before heat drying (g)) × 100 (%) Hereinafter, unless otherwise specified, the moisture content refers to the value calculated according to the above conditions and calculation method.

[0012] The viscosity in the present invention refers to a value measured using a Brookfield viscometer with a No. 3 rotor at 22°C and 30 rpm. Unless otherwise specified, the viscosity hereinafter refers to a value measured under the above conditions.

[0013] The mix of the present invention is characterized by having a moisture content of 75% or less and a viscosity of 300 mPa·s or less, measured at 22°C and 30 rpm using a Brookfield viscometer. This indicates that the mix of the present invention has low viscosity, is smooth and easy to drink, while still maintaining its richness and nutritional value compared to conventional mix. The concentration of the mix is ​​300 mPa·s or less, but may be 250 mPa·s or less or 200 mPa·s or less. The concentration may also be 50 mPa·s or more, 75 mPa·s or more, or 90 mPa·s or more.

[0014] The miki of the present invention can be produced by using at least sweet potato having an α-amylase activity of 0.15 U / g or more as a raw material.

[0015] The sweet potato used as the raw material for the milk in the present invention has an α-amylase activity of 0.15 U / g or more, preferably 0.30 U / g or more, more preferably 0.40 U / g or more. The α-amylase activity can be measured by the Ceralpha method, and specifically, for example, the α-amylase analysis kit from Megazyme.

[0016] The sweet potato used in the present invention may be any type of sweet potato as long as it has the above-mentioned α-amylase activity. For example, sweet potatoes that have been harvested and stored for a certain period of time to increase α-amylase activity to 0.15 U / g or more may be used as part or all of the raw sweet potato.

[0017] The temperature at which the sweet potatoes are stored for a certain period of time can be set, for example, in the range of 10 to 16° C., and preferably in the range of 13 to 15° C. If the storage temperature is too low, low-temperature damage such as discoloration and decay may occur, and if the temperature is too high, sprouting may begin, resulting in a decrease in quality.

[0018] The humidity during storage can be set in the range of 30 to 100%, preferably 50 to 100%, and more preferably 80 to 95%. If the humidity during storage is too low, there is a risk of dry damage, such as dry rot at both ends.

[0019] The number of days of storage can be adjusted depending on the storage conditions and the state of the sweet potato, and can be set to any number of days until α-amylase activity becomes sufficiently high, but is preferably 50 days or more, more preferably 70 days or more, and even more preferably 100 days or more.

[0020] The miki of the present invention can use rice and sugar in addition to sweet potato.

[0021] As the raw rice, any type of rice, such as non-glutinous rice or glutinous rice, can be used, and non-glutinous rice is more preferable. In addition, white rice may be used as it is without being crushed, or rice that has been crushed appropriately or powdered, such as mochi flour or joshinko, may be used.

[0022] Any sugar may be used as the raw material, such as granulated sugar, white sugar, brown sugar, granulated sugar, or brown sugar.

[0023] The milky mixture of the present invention contains the rice, sugar and sweet potato as mentioned above, but may also contain other ingredients such as malt, rice koji, sweeteners, acidulants, flavorings, fruit juice, salt, edible alcohol, edible organic acids, edible enzyme preparations, etc.

[0024] The miki of the present invention can be produced according to standard methods, for example, according to the methods described in Non-Patent Documents 1 and 2. Specifically, heated rice, sugar, and grated raw sweet potato are mixed together, and then fermented at 15 to 40°C for 1 to 3 days.

[0025] The amount of each ingredient and water can be adjusted as necessary, but for example, when heating rice, rice can be added to water, heated sufficiently until the rice becomes soft, and then cooled to room temperature before use. Sugar and sweet potato are added in a ratio of 0-800g sugar and 50-200g grated raw sweet potato per 1kg of rice obtained in this way, and then fermented at 15-30°C for 1-3 days.

[0026] If necessary, at the start of fermentation, Lacticaseibacillus paracasei, Lacticaseibacillus casei, or other Lacticaseibacillus bacteria, Lactobacillus gasseri, Lactobacillus acidophilus, Lactobacillus helveticus, Lactobacillus delbrueckii subsp. bulgaricus, Lactobacillus delbrueckii subsp. delbrueckii, Lactobacillus johnsonii, or other Lactobacillus species may be used as a starter. Lactobacillus bacteria such as Lactobacillus johnsonii, Ligilactobacillus bacteria such as Ligilactobacillus salivarius, Limosilactobacillus bacteria such as Limosilactobacillus fermentum, Liquorilactobacillus bacteria such as Liquorilactobacillus mali, Lactiplantibacillus bacteria such as Lactiplantibacillus plantarum, Streptococcus bacteria such as Streptococcus thermophilus, Lactococcus lactis subsp. lactis, Lactococcus lactis subsp. cremoris subsp.Examples of the lactic acid bacteria include Lactococcus bacteria such as Lactococcus cremoris, Lactococcus plantarum, Lactococcus raffinolactis, and Lactococcus cremoris, and Enterococcus bacteria such as Enterococcus faecalis and Enterococcus faecium. One or more of these lactic acid bacteria may be added.

[0027] The finished miki can be consumed as is, or can be sterilized by heat if necessary, and can also be used as an ingredient in other foods and beverages. EXAMPLES

[0028] The present invention will be described in detail below with reference to examples, but the present invention is not limited to these in any way.

[0029] (Example 1) Amylase activity evaluation of raw sweet potato Table 1 shows the results of measuring α-amylase activity and β-amylase activity in sweet potatoes stored for more than 100 days after harvest and, as a control, in sweet potatoes stored for less than 40 days after harvest.

[0030] <Method for measuring α-amylase activity> Measurement was performed using Megazyme's α-amylase assay kit (Ceralpha method). <β-amylase activity measurement method> Measurement was performed using Megazyme's β-amylase assay kit (Betamyl-3 method).

[0031] [Table 1]

[0032] As a result, there was no significant difference in β-amylase activity between the aged sweet potatoes and the control, whereas α-amylase activity was significantly higher in the aged sweet potatoes than in the control.

[0033] (Example 2) Production of Miki and Evaluation of Its Physical Properties The above two types of sweet potato, rice, and sugar were used as raw materials to produce Miki in a conventional manner. Specifically, 500g of rice was placed in 1.4L of water, heated to make a porridge-like consistency, and then thoroughly cooled to room temperature. 100g of sugar and 100g of raw sweet potato grated using a mixer or grater were added to this, mixed well, left to stand at room temperature for one day, and then put into a mixer. The sweet potatoes used were the aged sweet potato used in Example 1 and a control sweet potato.

[0034] The moisture content of the inventive Miki made from aged sweet potatoes and the control product made from control sweet potatoes was measured by normal pressure heat drying method. Specifically, each Miki was heat dried for 5 hours under 110°C conditions, and then the weight after heat drying was measured relative to the weight before heat drying, and the moisture content (%) was calculated as [(weight before heat drying)-(weight after heat drying)]÷(weight before heat drying)×100. As a result, the moisture content of the inventive Miki was 75%, and the moisture content of the control Miki was 74%.

[0035] Table 2 shows the results of a comparison of the viscosity of the mix of the present invention made using aged sweet potatoes and the control product made using control sweet potatoes. The viscosity of the present invention and the control product was also measured and compared after heating them at 65°C for 10 minutes. The viscosity was measured using a TVB-10M viscometer (Toki Sangyo) with a rotor TM3, a rotation speed of 30 rpm, and a temperature of 22°C.

[0036] [Table 2]

[0037] As a result, it was found that the mixture of the present invention had a lower viscosity than the control. Furthermore, it was found that the viscosity remained lower than the control even after heating at 65°C for 10 minutes.

[0038] (Example 3) Production of Miki and Evaluation of its Physical Properties 2 Two kinds of sweet potatoes, rice, and sugar mixed in the ratios shown in Table 3 were used as raw materials to produce Miki in a conventional manner. Specifically, 500g of rice was placed in 1.4L of water, heated to make a porridge-like consistency, and then thoroughly cooled to room temperature. 100g of sugar and 100g of raw sweet potato grated using a mixer or grater were added to this, mixed well, left to stand at room temperature for one day, and then put into a mixer. The sweet potatoes used were the aged sweet potatoes used in Example 1 and a control sweet potato.

[0039] The viscosity of the mix made from aged sweet potatoes and the control sweet potatoes is compared in Table 4. The viscosity was measured using a TVB-10M viscometer (Toki Sangyo) with a rotor TM3 at a rotation speed of 30 rpm and a temperature of 22°C.

[0040] [Table 3]

[0041] [Table 4]

[0042] As a result, it was found that the mixes of the present invention shown in Nos. 1 to 4 had lower viscosity than the control.

[0043] (Example 4) Various evaluations of Miki (a) Evaluation of residual adhesion to containers The mix of the product of the present invention and the control product produced in Example 2 was filled into a 500 mL PET bottle, the lid was opened, the bottle was turned upside down, and the contents were poured out for one minute. The weight of the mix remaining on the PET bottle was then measured, and it was 10.2 g for the control product and 6.1 g for the product of the present invention. This shows that the product of the present invention is less likely to remain on the container.

[0044] (a) Sensory evaluation A sensory evaluation was carried out on the mix of the product of the present invention and the control product produced in Example 2. The evaluation was carried out by seven well-trained in-house panelists, and the method of assigning scores was thoroughly shared among the panelists in advance. In five evaluation categories, sweetness, sourness, umami, bitterness, and smoothness, the control product was given a score of 3 points, and the product of the present invention was given a score (1 point: weak or not smooth to 5 points: strong or smooth), and the average value was calculated. The results are shown in Figure 1.

[0045] As shown in FIG. 1, the product of the present invention is not only superior in terms of smoothness compared to the control product, but also, completely unexpectedly, its taste was found to be enhanced in sweetness while being perceived as having a weak sourness.

Claims

1. A mixture having a moisture content of 75% or less and a viscosity of 300 mPA·s or less, measured at 22°C and 30 rpm using a Brookfield viscometer with a No. 3 rotor.

2. The method for producing Miki according to claim 1, characterized in that the Miki is produced using at least sweet potato having an α-amylase activity of 0.15 U / g or more as a raw material.

3. The method for producing miki according to claim 2, wherein the sweet potato having an α-amylase activity of 0.15 U / g or more is a sweet potato stored for 50 days or more after harvest under conditions of a temperature of 0 to 40 ° C. and a humidity of 30 to 100%.

4. The method for producing miki according to claim 3, wherein the sweet potato having an α-amylase activity of 0.15 U / g or more is a sweet potato stored for 50 days or more after harvest under conditions of a temperature of 10 to 15 ° C. and a humidity of 85 to 95%.

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