Method for producing ultrafine soybean powder, and soy milk composition containing ultrafine soybean powder produced by this method.

Abstract

The present invention relates to a method for producing ultrafine soybean powder, which deviates from the conventional production method of recovering soybean hulls, pulverizes soybeans whole, is excellent nutritionally, and has a small particle size, so it is excellent in throat passage and sensory properties when applied to beverage products. The present invention can provide a method for producing ultrafine soybean powder and a beverage using the ultrafine soybean powder produced by the method.

Description

[Technical Field]

[0001] The present invention relates to a method for producing soybean powder and a soy milk composition containing ultrafine soybean powder produced by this method. More specifically, it relates to a method for producing fine soybean powder, which is rich in nutrients and has a smooth texture when processed into soy milk, by grinding whole soybeans, and to a soy milk composition containing ultrafine soybean powder produced by this method. [Background technology]

[0002] Soybeans have long been a major source of protein and fat in Asia, where grains are the staple food. In particular, the protein that makes up more than 40% of soybeans is equivalent to the protein in milk and eggs, which contains a balanced amount of essential amino acids, making it an excellent source of protein for Asians who often lacked sufficient protein intake. Furthermore, soy protein is excellent not only in terms of nutritional value but also in terms of physiological activity, and has been reported to play a role in lowering serum cholesterol levels and reducing the incidence of diseases such as cancer, osteoporosis, and cardiovascular disease. Soybeans are used in a wide variety of ways, from being consumed at home in dishes such as bean sprout salads and boiled beans, to being commercially processed into tofu and soy milk.

[0003] Traditional soy milk production methods typically involved heating boiled or soybeans soaked in water, then grinding and compressing them. However, this method resulted in undesirable flavors and tastes, as well as the leaching of lipids from the soybeans and the formation of precipitates due to the large size of the soy milk particles after production. Therefore, to prevent these issues, soy milk products are now being industrialized using chemical additives such as emulsifiers, thickeners, and flavorings.

[0004] Furthermore, conventional techniques have drawbacks such as the potential for nutrient destruction due to temperature increases during the soybean powder grinding step, resulting in larger particle sizes, discarded bean hulls, and reduced production efficiency. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Korean Registered Patent Publication No. 10-1070823 [Patent Document 2] Korean Registered Patent Publication No. 10-1440609 [Overview of the project] [Problems that the invention aims to solve]

[0006] The present invention aims to solve the above-mentioned problems, and its objective is to provide a method for producing ultrafinely ground soybean powder that is nutritionally superior and has a smooth texture when applied to beverages, by pulverizing the entire soybean into ultrafine particles, deviating from the conventional method of producing soy milk by removing the skin of the soybean, and a soy milk composition containing the soybean powder produced by this method. [Means for solving the problem]

[0007] To achieve the above objective, the present invention provides a method for producing ultrafine soybean powder, comprising the following steps: (a) The step of drying the soybeans; (b) A step of first grinding the dried soybeans; (c) A step of grinding the primary ground soybeans a secondary time; (d) A step of pre-treating the secondary ground soybeans; (e) A step of air-jetting the pre-treated soybeans.

[0008] Step (a) above is a step of drying soybeans, and the soybeans used in this step are, but are not limited to, raw soybeans that have not been hulled.

[0009] The drying conditions are 40-90°C, preferably 50-80°C, for 4-10 hours, preferably 5-9 hours.

[0010] If drying is carried out at a temperature and for a time less than the specified drying temperature and drying time, the drying process may not proceed smoothly, and the soybeans may not be properly pulverized in the subsequent pulverization step. If the temperature range and drying time range are exceeded, the soybeans may burn or be over-dried, and there is a risk that the skin will be removed during pulverization.

[0011] The soybeans that have undergone the drying step may have a moisture content of 2 - 10% (w / w), preferably 2 - 8% (w / w), and more preferably 6 - 8% (w / w). If the moisture content is less than the above range, the skin can be easily removed during soybean pulverization. If the moisture content exceeds the above range, the soybeans may be shredded and the pulverization may not proceed smoothly.

[0012] The step (b) is a step of primary pulverization of the soybeans dried through the step (a). At this time, the interval between the roll mills is set to 2 - 5 mm, and primary pulverization is carried out to a soybean size of 2 - 5 mm. This is a pretreatment step for the target particle size during secondary pulverization and is also for providing appropriate roasting conditions.

[0013] The step (c) is a step of secondary pulverization of the soybeans that have been primary pulverized through the step (b), and it is a step of pulverizing the primary pulverized soybeans again so that heat transfer can be carried out well in the subsequent pretreatment step. At this time, the soybeans can be pulverized to a size of 1 - 10 mm, preferably 2 - 6 mm. If it is outside the range of the pulverized size, the heat transfer efficiency may decrease during the roasting process, and it may be difficult to adjust the particle size in the subsequent airflow pulverization step.

[0014] The step (d) is a step of pretreating the soybeans that have been secondary pulverized through the step (c), and the pretreatment includes a process of roasting and cooling the soybeans.

[0015] At this time, it can be preheated at 140 to 190°C, preferably 150 to 180°C, before roasting. If the preheating process is not carried out, since heat is continuously applied to the raw material until the roasting temperature is reached, there is a risk of a burnt taste or a decrease in quality.

[0016] After the preheating process, roasting is carried out at 160 to 240°C, preferably 180 to 220°C, more preferably 190 to 210°C for 40 to 80 minutes, preferably 50 to 70 minutes. If the roasting temperature is below the above range, there may be a raw smell because the roasting is not properly carried out. If the roasting temperature exceeds the above range, there may be a burnt taste because the soybeans are over-roasted.

[0017] After roasting, the cooling process is carried out at 10 to 40°C, preferably 20 to 30°C. If the temperature is below the above range, the moisture bound to the soybeans may freeze, and when airflow pulverization is carried out, the oil and moisture may escape due to a sudden temperature rise, resulting in a decrease in quality. Also, if the temperature exceeds the above range, it may deteriorate due to the combination of oxygen in the air and the oil in the soybeans, resulting in a decrease in quality, and airflow pulverization may not be smoothly carried out at high humidity during airflow pulverization.

[0018] Also, the cooling is not limited, but in one embodiment of the present invention, it can be carried out by natural cooling.

[0019] The step (e) is a step of airflow pulverizing the soybeans pretreated by roasting and cooling as described above. The temperature during the pulverization is not limited, but is preferably maintained at 10 to 30°C, and the input rate of the soybeans can be 5 to 25 kg / h, preferably 10 to 20 kg / h. The reason for setting the pulverization temperature range as described above is that due to the temperature rise by the motor during airflow pulverization, especially in the high temperature in summer, the humidity is high, so the humidity remains in the powder raw material, and airflow pulverization cannot be smoothly carried out, and there is a risk that the particle size becomes uneven.

[0020] Furthermore, the reason for setting the input speed range as described above is that if the input speed is too high, the airflow pulverization does not proceed smoothly, resulting in a larger particle size. Conversely, if the input speed is too low, the particle size becomes smaller, but production efficiency decreases.

[0021] Furthermore, the pulverizer motor can pulverize at a rotational speed of 3,000 to 5,000 RPM, preferably 3,000 to 4,000 RPM, and more preferably 3,400 to 4,000 RPM, and the dust collector motor can pulverize at a rotational speed of 500 to 2,000 RPM, preferably 900 to 1,600 RPM, and more preferably 1,100 to 1,300 RPM. If pulverization is performed at a rotational speed below the range of the pulverizer motor and dust collector motor, the soybeans may not be pulverized properly and may remain stationary. If the speed exceeds the above speed range, the particle size may be too small, which may reduce production efficiency when applied to soy milk.

[0022] The particle size of the soybeans ground through the grinding step may be 10 to 60 μm, preferably 15 to 50 μm. If the soybean size is less than the above range, there is no problem, but the production efficiency decreases when manufactured artificially, and if the soybean size exceeds the above range, the particle size may be coarse when manufactured into soy milk.

[0023] The air-jet pulverization method has the advantage of producing raw materials with less damage due to collisions between the materials themselves rather than friction between the equipment and the materials, and of obtaining raw materials with fine particle sizes.

[0024] The present invention further provides a soy milk composition or soy milk product containing soybean powder ground by the above method. [Effects of the Invention]

[0025] The present invention provides a method for producing ultrafinely ground soybean powder. The soybean powder produced by the above method is easily solubilized in water and can provide beverages with a smooth texture when added to drinks.

[0026] Furthermore, the ultrafinely ground soy milk powder produced by the present invention retains more nutrients compared to conventional grinding methods, and when used to produce soy milk, it is possible to provide soy milk with superior sensory evaluation results. [Brief explanation of the drawing]

[0027] [Figure 1] This figure shows the CIE Lab color space used to evaluate color difference in Experimental Example 2. [Figure 2] This diagram shows the principle of the particle size analyzer used in the particle size analysis in Experimental Example 4. [Figure 3a] This figure shows the average particle size of the ultrafine soybean powder produced in Experimental Example 4. [Figure 3b] This figure shows the average particle size of the ultrafine soybean powder produced in Experimental Example 4. [Figure 3c] This figure shows the average particle size of soybean powder in a liquid soy milk product produced using the ultrafine soybean powder manufactured in Experimental Example 4. [Figure 3d] This figure shows the average particle size of soybean powder in a liquid soy milk product produced using the ultrafine soybean powder manufactured in Experimental Example 4. [Modes for carrying out the invention]

[0028] The present invention will be described in detail below with reference to examples and experimental examples.

[0029] However, the following examples and experimental cases are merely illustrative of the present invention, and the content of the present invention is not limited to the following examples and experimental cases.

[0030] <Example> Production of ultrafine ground soybean powder according to the present invention The incoming raw soybeans were visually inspected for foreign matter, mold, rotten beans, and uniformity of size, and raw soybeans of superior quality were selected. The selected raw soybeans were evenly dispersed onto drying trays and placed in a dryer, where they were dried at 50-80°C for 5-9 hours until the moisture content was approximately 8% (w / w) or less.

[0031] Subsequently, the dried soybean material was first ground into soybean-sized pieces of 2-5 mm using a roll mill with a spacing of 2-5 mm.

[0032] The soybeans, which had been ground as described above, were fed into a screw-type grinder and, with the mesh size set to ensure an effective roasting process, were secondarily ground into small particles of 2-6 mm.

[0033] The ground soybean raw material was placed in a heat transfer drum rotating roaster and roasted at 180-220°C for 50-70 minutes to remove any raw odor and maximize the savory flavor. After that, the temperature and time for roasting were set, and a colorimeter was used to determine whether the color was appropriate.

[0034] Next, the roasted soybean raw material was allowed to cool naturally at room temperature, and then fed into an air-flow pulverizer at a rate of 10-20 kg / h, with the pulverizer rotation speed set to 3,400-4,000 RPM and the dust collector rotation speed set to 1,000-2,000 RPM to produce a soft, ultrafine soybean powder with a particle size of 15-50 μm.

[0035] Each of the above steps was set based on the results of the experimental example described below.

[0036] <Experimental Example 1> Evaluation of Soybean Drying Conditions In this invention, in order to evaluate the effect of soybean drying conditions on the production of soybean powder, raw soybeans were dried at different temperatures and for different times as described below, and then ground: -Condition 1: Dry at 40-70°C for 3-6 hours -Condition 2: Dry at 40-70°C for 5-9 hours -Condition 3: Dry at 50-80°C for 3-6 hours -Condition 4: Dry at 50-80°C for 5-9 hours -Condition 5: Dry at 70-100°C for 3-6 hours -Condition 6: Dry at 70-100°C for 5-9 hours.

[0037] The experimental results showed that under condition 1, the moisture content was 12% (w / w) or higher, causing the soybeans to be finely chopped during roll mill grinding, resulting in uneven grinding. Under condition 2, the moisture content was 10% (w / w) or higher, causing the soybeans to be finely chopped during roll mill grinding, resulting in uneven grinding. Under condition 3, the moisture content was 8% (w / w) or higher, causing the soybeans to be finely chopped during roll mill grinding, resulting in uneven grinding. In contrast, under condition 4, the moisture content was 8% (w / w) or lower, resulting in uneven grinding of the soybeans during roll mill grinding.

[0038] When conducted under condition 5, the moisture content was 6% (w / w) or less, and during roll mill grinding, the soybeans were pulverized and the skins were blown away. When conducted under condition 6, the moisture content The quantity was less than 4% (w / w), and air-jet milling was difficult because the soybeans were pulverized and the skins were blown away during roll mill grinding.

[0039] Based on the above results, Experimental Example 2 was conducted under the conditions of Condition 4 in Experimental Example 1.

[0040] <Experimental Example 2> Evaluation of Roasting Conditions Raw soybeans are pale yellow and have a fishy taste when consumed. When roasted under appropriate conditions, they change from pale yellow to dark yellow, and the fishy smell disappears, replaced by a savory taste. To evaluate the chromaticity corresponding to the removal of the fishy taste and the resulting savory taste, a colorimeter was used to evaluate soybeans with different roasting temperatures and times as follows.

[0041] -Condition 1: Roast at 180℃ for 50-70 minutes -Condition 2: Roast at 180℃ for 70-90 minutes -Condition 3: Roast at 200℃ for 50-70 minutes -Condition 4: Roast at 200℃ for 70-90 minutes.

[0042] CIE L for color difference detection * a * b * In the color space, L* The value represents lightness, L * When L = 0, it represents black, and when L * = 100, it represents white. a * represents which side it is biased towards, red or green. a * If a is negative, it is a greenish color, and a * if a is positive, it is a red / purpleish color. b * represents yellow and blue. b * If b is negative, it represents blue, and b * if b is positive, it represents yellow (see Figure 1).

[0043] As a result of the evaluation, when carried out under Condition 1, it was confirmed that there was a weak fishy odor during ingestion and the fragrant taste increased slightly. The color difference was L * 73.2 / a * 10.9 / b * 27.8

[0044] When carried out under Condition 2, there was no fishy odor during ingestion, and it had a fragrant taste and a roasted taste. The color difference was L * 69.5 / a * 11.3 / b * 26.2

[0045] When carried out under Condition 3, there was no fishy odor during ingestion, and the fragrant taste was well felt. The color difference was L * 71.5 / a * 10.5 / b * 26.4

[0046] When carried out under Condition 4, there was no fishy odor during ingestion, but the roasted taste increased strongly. The color difference was L * 65.2 / a * 12.5 / b * 28.1 。

[0047] Based on the above results, the soybeans produced under Condition 3 had no raw bean odor and the fragrant taste increased. Therefore, Experimental Example 3 was carried out with the conditions set as described above.

[0048] <Experimental Example 3> Evaluation of airflow pulverization conditions The air-jet pulverization step requires setting the raw material input rate, the airflow rotation speed of the air-jet pulverizer, and the dust collection rotation speed to ensure applicability and process ultrafine soybean powder with a soft particle size. Therefore, the effects on the manufacturing process were evaluated by varying the motor rotation speed and dust collection rotation speed conditions as follows.

[0049] -Condition 1: Motor rotation speed 3,400 RPM, dust collection rotation speed 900~1,600 RPM -Condition 2: Motor rotation speed 3,600 RPM, dust collection rotation speed 900~1,600 RPM -Condition 3: Motor rotation speed 3,800 RPM, dust collection rotation speed 900~1,600 RPM -Condition 4: Motor rotation speed 4,000 RPM, dust collection rotation speed 900~1,600 RPM.

[0050] The evaluation results showed that when the experiment was conducted under condition 1, the raw material dust collection efficiency in the recovery device decreased, and the raw material (crushed soybeans) in the air-jet pulverizer remained stationary. At this time, the particle size of the soybeans was D50μm (37.90~38.79μm) and D90μm (111.5~124.1μm).

[0051] When the process was carried out under condition 2, some dust collection of raw materials was performed in the recovery device, but production efficiency decreased and the target particle size was not reached. The particle sizes of the soybeans at this time were D50μm (35.52~36.47μm) and D90μm (102.57~109.9μm).

[0052] When the experiment was conducted under condition 3, appropriate dust collection efficiency and particle size were obtained, particularly at a dust collection rotation speed of 1,100 to 1,300 RPM. At this time, the particle size of the soybeans was D50 μm (33.47 to 38.94 μm) and D90 μm (85.7 to 101.73 μm).

[0053] When the experiment was conducted under condition 4, the raw material dust collection efficiency in the recovery device decreased, and the raw material in the air-jet pulverizer remained still. At this time, the particle size of the soybeans was D50μm (32.06~36.01μm) and D90μm (63.46~74.02μm).

[0054] Based on the results above, the dust collection efficiency and particle size of the air-pulverized raw material under condition 3 were deemed appropriate, and therefore, experimental examples 4 and 5 were conducted under the above conditions.

[0055] <Experimental Example 4> Evaluation of particle size of ground soybean powder To determine the average particle size of ultrafine soybean powder obtained by passing soybeans through an air-jet mill, and the soy milk to which this powder was applied, the following experiment was conducted.

[0056] Of the soybean powder obtained by air-jet pulverization in Experimental Example 3, the pulverized soybean powder obtained under condition 3 was sent to the Korea Polymer Testing Institute for Analysis, an external analytical institution. The analysis was performed using measuring equipment (laser diffraction and scattering ISO 13320) capable of analyzing particle size (0.4~2,000 μm) while the powder is still in powder form. Particle size D10, D50, and D90 were measured, and the average particle size was calculated. The number of repetitions was 3.

[0057] The core principle of laser particle size analyzers is that when light is shone on a particle, the intensity and scattering angle of the scattered light are detected by a detector, and the particle size is calculated based on this information. The theories used to determine particle size are Fraunhofer diffraction and Mie theory. These theories utilize diffraction phenomena to measure the size distribution of particles, and are based on the principle that scattering intensity is proportional to particle size and scattering angle is inversely proportional to particle size (Figure 2).

[0058] The experimental results showed that the average particle size of the ultrafinely ground soybean powder produced under the above conditions was 38.88 μm to 40.55 μm (Figures 3a and 3b).

[0059] <Experimental Example 5> Sensory evaluation of soy milk containing ultrafine soy powder produced by the present invention Using the ultrafine soybean powder obtained as a result of Experiment Example 4, a panel of 32 people in their 40s and 50s was recruited to evaluate the major sensory attribute preferences (overall preference (frequency of selection) / overall preference / detailed attribute preferences (appearance, aroma, taste, mouthfeel, aftertaste)) for the soy milk product.

[0060] The external testing was conducted by Sensometrics Sensory Evaluation Center Co., Ltd., where evaluators were provided with 100ml of each type of soy milk for evaluation. The results are shown in Tables 1 and 2.

[0061] The evaluation results showed that the soy milk according to the present invention had a significantly higher overall preference than its competitors (95% confidence level). Regarding the differences in detailed attribute preferences between the two products, the appearance was not significantly different, but the aftertaste, mouthfeel, and flavor of the soy milk according to the present invention were rated far higher in sensory evaluation, and the aroma of the soy milk according to the present invention was also rated slightly higher (95% confidence level).

[0062] [Table 1]

[0063] [Table 2]

Claims

1. (a) The step of drying soybeans, (b) The step of first grinding the dried soybeans, (c) The step of grinding the primary ground soybeans into secondary ground soybeans, (d) A step of pre-treating the secondary crushed soybeans by roasting and cooling, (e) A method for producing ultrafine soybean powder in which the entire soybean is ground without removing the skin, comprising the step of air-jetting the pre-treated soybeans.

2. The method for producing ultrafine soybean powder according to claim 1, characterized in that step (a) is drying soybeans at 50 to 80°C for 5 to 9 hours.

3. The method for producing ultrafine soybean powder according to claim 1, characterized in that the soybeans dried after step (a) have a moisture content of 6-8% (w / w).

4. The method for producing ultrafine soybean powder according to claim 1, characterized in that step (c) is to grind soybeans to a size of 2 to 6 mm.

5. The method for producing ultrafine soybean powder according to claim 1, characterized in that the roasting in step (d) is carried out at 190 to 210°C for 50 to 70 minutes.

6. The method for producing ultrafine soybean powder according to claim 1, characterized in that the soybeans are preheated to 150 to 180°C before roasting in step (d).

7. The method for producing ultrafine soybean powder according to claim 1, characterized in that the cooling in step (d) is performed at 20 to 30°C.

8. The method for producing ultrafine soybean powder according to claim 1, characterized in that the air-jet pulverization in step (e) is performed by maintaining the temperature at 10 to 30°C and feeding in soybeans at a rate of 10 to 20 kg / h.

9. The method for producing ultrafine soybean powder according to claim 1, characterized in that the air-jet pulverization in step (e) is performed at a rotational speed of 3,000 to 4,000 RPM for the pulverizer motor and a rotational speed of 900 to 1,600 RPM for the dust collector motor.

10. The manufacturing method is characterized by grinding soybeans to a size of 15 to 50 μm, as described in claim 1.

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