CN114947154A - A kind of mung bean pre-processing method and high-efficiency peeling machine - Google Patents

Abstract

The invention relates to a mung bean peeling pretreatment method and an efficient peeling machine, belonging to the technical field of preliminary processing of agricultural products. The method of the invention comprises the following steps: firstly, spraying 3 +/-1% of sodium chloride aqueous solution on mung beans to wet the mung beans so that the water content of the mung beans reaches 11.5 +/-2%; secondly, freezing the mung beans after the moisture spraying treatment at minus 15 +/-2 ℃ for more than 5 hours; thirdly, intermittently heating the frozen mung beans by using microwaves, heating the mung beans to 50 +/-1 ℃ for the first time, preserving the heat for 1-1.2min, and turning over for 10-15 s; heating to 50 + -2 deg.C for the second time, and maintaining the temperature for 2-2.2 min; and fourthly, placing the mung beans heated by the microwaves into a mung bean peeling machine, and stopping the machine after peeling. The invention not only innovates the steps of the mung bean peeling pretreatment by the quasi-dry method which is different from the traditional wet method and the dry method, but also determines the ideal control parameters of each step through repeated tests and continuous groping, thereby not only avoiding the defects of long processing time by the wet method, large water consumption and easy pollution, but also overcoming the defects of low yield and rice yield of the mung bean peeling by the dry method.

Description

A kind of mung bean pre-processing method and high-efficiency peeling machine

technical field

The invention relates to a pre-peeling treatment method, in particular to a mung bean pre-peeling treatment method, and also relates to a high-efficiency peeling machine that is helpful for realizing the method, belonging to the technical field of primary processing of agricultural products.

Background technique

Mung bean skin accounts for 6%-10% of mung bean, and its main components are cellulose substances and less fatty substances. Peeling can not only effectively control the protein content of soybean meal and diversify products, but also greatly improve the quality of mung bean products and increase product competitiveness. There are two kinds of traditional green bean peeling methods: wet method and dry method. Typical wet peeling first soaks mung beans with a large amount of water, then peels them with conventional peeling equipment, and then dries the bean kernels. The disadvantage is that the processing time is long, the water consumption is large, and it is easy to cause sewage discharge and environmental pollution. Dry peeling is directly peeled by using suitable peeling equipment (such as the peeling machine disclosed in Chinese patent application number 201410042298.2) under the condition of conventional storage moisture content. It is becoming more and more widespread, but the dry peeling equipment directly peels the mung beans without proper pretreatment, and there are still the shortcomings of low peeling qualification rate and low rice yield. In particular, with the continuous improvement of people's dietary requirements, the quality requirements of mung bean products on raw materials such as soybean flour are also getting higher and higher, and the existing wet and dry peeling methods are difficult to meet the increasing technical requirements for mung bean peeling.

For this reason, research on new peeling methods has received attention. The Chinese patent application with application number 202111405776.8 discloses an innovative method for soybean peeling at low temperature, including pretreatment; ultrasonic impurity removal, primary ventilation and drying, primary refrigeration, primary thawing, secondary refrigeration, secondary thawing, and secondary ultrasonic waves Treatment, soaking treatment, secondary ventilation and drying, tertiary refrigeration, tertiary thawing, tertiary ventilation drying, vacuum microwave shell breaking and sieving of soybean skins and other steps. However, practice shows that applying it to mung bean peeling not only has complicated equipment and long process, but also compared with soybeans, mung bean has a relatively irregular shape and an ellipsoid shape, rather than a near-spheroid of soybean, and the mung bean skin is surrounded by the germ combined with the mung bean germ. The combination is extremely tight and has a slight depression. The traditional dry peeling is difficult to grind to the depression during the grinding process of the grinding wheel, so that the mung bean skin with the germ as the center cannot be peeled off during the peeling process, so that the qualified rate of mung bean peeling is poor. Difficult to meet peeling needs.

SUMMARY OF THE INVENTION

The object of the present invention is: in view of the shortcoming existing in the above-mentioned prior art, a kind of mung bean peeling pretreatment method that lays a foundation for the completion of mung bean peeling with high quality and high efficiency is proposed, so that the mung bean skin is pretreated before peeling and is separated from the bean embryo by gas explosion, At the same time, with the help of the mechanical structure, the mung bean skins fall off into pieces, and the green skins around the bean embryos are removed smoothly, so as to achieve high-efficiency peeling, ensure the quality of mung bean peeling, improve the peeling efficiency, and effectively meet the demand for high-quality mung bean products for raw materials.

In order to achieve the above purpose, the applicant, on the basis of in-depth research on the mung bean peeling mechanism, through repeated tests, has proposed the basic technical scheme of the mung bean peeling pretreatment method of the present invention, comprising the following steps:

The first step is to spray the mung bean with 3±1% sodium chloride aqueous solution to make its moisture content reach 11.5±2%;

The second step is to freeze the mung bean after the wet spray treatment for more than 5 hours at -15±2°C;

The third step is to intermittently heat the frozen mung beans with microwaves. For the first time, heat to 50±1°C, keep the temperature for 1-1.2min, and then turn it for 10-15s; for the second time, heat it to 50±2°C and keep the temperature for 2- 2.2min;

Step 4: Put the microwave-heated mung bean into the mung bean peeling machine, and stop after peeling.

After that, the peeling machine was used for peeling, and as a result, the qualified rate and the rice yield were significantly improved. The invention not only innovates the pre-processing steps of quasi-dry mung bean peeling which is different from the traditional wet method and dry method, but also determines the ideal control parameters of each step through repeated trials and groping, thereby avoiding the long time and consumption of wet processing. The disadvantages of large amount of water and easy pollution also overcome the shortcomings of the green skin at the germ of the dry-peeled mung bean being difficult to grind and fall off, resulting in a low pass rate and low rice yield.

At the same time, the applicant has further researched and found that: compared with other beans, because the mung bean husks around the mung bean germ are very tightly bound and have slight depressions, the traditional dry peeling is difficult to grind to the ground in the grinding wheel grinding process. In the depression, the mung bean skin with the germ as the center cannot be removed during the peeling process, so that the qualified rate of mung bean peeling is poor, and it is difficult to meet the peeling needs. When the pre-treated mung beans are peeled, because the bean skin has burst, it is not simply "friction" peeling, but "tear" peeling. This "tear" peeling is just right to remove the mung bean skin layer, especially to make The mung bean skin after the gas explosion will fall off in lumps under the action of tearing, and the green skin around the mung bean germ can be effectively peeled off in lumps, thereby significantly improving the pass rate and rice yield. Inspired by this, a special and high-efficiency peeling machine especially suitable for the method of the present invention was invented: the top of the machine frame supports a rotatable drum located in the box and a same rotating drum located in the drum and opposite to the drum. Shaft grinding wheel roller; one side of the box is provided with an air inlet, and the lower part is provided with a funnel with a material outlet;

The peripheral wall of the drum is evenly spaced with copying plates inclined forward in the direction of rotation, the peripheral wall has a circumferentially extending oblong hole forming a mesh, the oblong hole has a serrated edge, and the oblong hole is spaced along the circumferential direction. , each row of oblong holes is distributed at axial intervals, forming a lattice distribution;

The circumferential interval between the oblong holes in the adjacent rows distributes rolling edges with circular arc edges extending into the peripheral wall. Tangentially perpendicular to the peripheral wall.

When the high-efficiency peeling machine of the present invention is used to peel the pre-treated mung beans, gaps have been formed between the bean embryo and the bean skin due to the different shrinkage coefficients, and the bean skin has formed cracks. In the middle, it constantly falls on the impact rolling blade, so that the edge of the blade has a high probability of cutting into the bean skin, producing a "prying" effect, causing it to be torn and separated from the bean shell, so that it can be smoothly and completely peeled off in the subsequent rolling process.

A further improvement of the present invention is that: the rolling edge is formed by punching and drawing, and the punching edge of the rolling edge is drawn to form an arc edge. In this way, the manufacturing process of the rolling edge is good, and it can be manufactured simultaneously with the oblong hole.

The further improvement of the present invention is that: the long sides of the oblong holes are in a zigzag shape, and the geometric centers of the oblong holes in adjacent rows are dislocated. In this way, the mung bean can be peeled off more effectively and thoroughly with the help of sawtooth scraping during the discharge process, and the green skin around the germ can be smoothly torn off by scraping and tearing, which further improves the peeling qualification rate.

A further improvement of the present invention is that: the surface of the copying plate facing the rotation direction has rows of raised circular truncated truncated truncated truncated truncated truncated truncated truncated truncated truncated truncated truncated truncated truncated truncated truncated truncated truncated truncated truncated troughs. The round tables are staggered. During the process of mung bean being picked up, the round table can use its own weight and pressure to forcefully rub and loosen the mung bean skin and the raised round table, making it easier to fall off. Appropriate spacing can effectively prevent the mung beans from being stuck and blocked between the round tables during the process of being picked up.

The further improvement of the present invention is: the convex circular platform is alternately distributed according to the regularity of one row of sparse intervals and the next row of dense intervals, the size of the sparse intervals is 3-5 times the average particle size of mung bean, and the size of the dense spacing is the average size of mung bean 1.5-2.5 times the particle size. In this way, after the mung bean is picked up by the copy board, it can complete the complete multiple friction process along the interval between adjacent rows, and the friction with the round table of the copy board is more thorough, which is further conducive to the loosening and falling off of the bean skin, which is more conducive to the mung bean. peeling.

The further improvement of the present invention is: the rotational speed of the drum is 1000±50 r/min, and the reverse rotational speed of the grinding wheel roller is 20±2 r/min. This speed is the ideal matching speed obtained by the test.

Description of drawings

The present invention will be further described below in conjunction with the accompanying drawings.

FIG. 1 is a schematic structural diagram of an embodiment of the present invention.

FIG. 2 is a schematic structural diagram of the roller assembly in the embodiment of FIG. 1 .

FIG. 3 is a left side view of FIG. 2 .

FIG. 4 is a schematic diagram of an expanded and enlarged structure at A of FIG. 3 .

FIG. 5 is a left side view of FIG. 4 .

FIG. 6 is a schematic diagram of a partially enlarged structure at B in FIG. 5 .

FIG. 7 is a view taken along arrow C of FIG. 6 .

FIG. 8 is a schematic diagram of the structure of the copy board in the embodiment of FIG. 1 .

FIG. 9 is an enlarged schematic view of the bottom view of FIG. 8 .

Detailed ways

Example 1

The concrete steps of the mung bean dehulling pretreatment method of the present embodiment are:

The first step is to spray the mung bean with 3±1% sodium chloride aqueous solution to make the water content reach 11.5±2%. A large number of experimental studies have shown that although salt water can accelerate the infiltration of water, it is easy to affect the quality of mung bean when the concentration is high. About 3% brine is the lowest priority concentration that can still effectively accelerate the penetration of water into the mung bean and effectively ensure the quality of the mung bean. If the rate is too low, the water vaporization will not be enough to burst the mung bean skin layer, and it is difficult to achieve the separation of the bean embryo and the bean skin; and if the moisture is too high, it will not only increase the drying time, but also increase the risk of mildew and affect the quality of the bean embryo; about 11.5 % moisture content can effectively burst the bean skin and easily separate from the bean embryo. The effect is the most ideal, and after microwave heating, the water is lost, and the mung bean can achieve safe storage of moisture without subsequent drying.

The second step is to freeze the mung bean after wet spraying at -15±2°C for more than 5 hours. Through experiments and research, it can be seen that the mechanical properties of the bean embryo change little, while the bean skin will become brittle and hard, and the bean embryo contains far more starch than the bean skin, so the shrinkage coefficients of the two are very different during freezing. Appropriate low-temperature treatment under the condition of moisture content can lay a good foundation for the subsequent microwave heating to crack the bean skin; repeated experiments found that if the mung beans after appropriate spray moisture treatment were placed at about -15 ℃ and frozen for more than 5 hours, the bean skin was easier to be heated during microwave heating. burst to form a rift.

The third step is to intermittently heat the frozen mung beans with microwaves. For the first time, heat to 50±1°C, keep the temperature for 1-1.2min, and then turn it for 10-15s; for the second time, heat it to 50±2°C and keep the temperature for 2- 2.2min. Research and experiments have shown that: after the heating temperature of mung bean is higher than 50 degrees for a certain period of time, the protein and polyphenol complexes contained in it will be significantly destroyed, other nutrients will also be reduced, and the bean embryo will also appear brown. When the skin of the frozen mung bean bursts, in order to ensure the quality of future soy products, the temperature and time must be well controlled.

Step 4: Put the microwave-heated mung bean into the mung bean peeling machine, and stop after peeling. After that, the results of peeling the pre-treated and untreated mung beans with a peeling machine showed that the peeling qualification rate of the former could be increased by more than 20% on average, and the rice yield was also significantly improved.

In order to better realize the method of this embodiment, on the basis of further research on the working principle of the peeling machine, the high-efficiency peeling machine of this embodiment is technologically innovated. As shown in FIG. 1 , the top of the frame 12 supports the The drum 5 is rotatable, and the drum 5 is equipped with a grinding wheel 6 with an opposite direction of rotation. The lower two sides of the box body 4 are respectively provided with a driving sprocket 17 and a driven sprocket 13. The drum motor 14 drives the driving sprocket 17 through the coupling transmission mechanism. The driving sprocket 17 drives the driven sprocket 13 through the transmission chain belt 8. , the large sprocket 16 coaxially fixed with the drum 5 meshes with the drive chain 8 that surrounds the driving sprocket 17 and the driven sprocket 13 .

The box 4 with the top cover 7 on the top is equipped with a grinding wheel motor 9 that drives the grinding wheel 6 through a belt drive, and a dust exhaust fan 2 is installed on the other side. It communicates and has an air outlet 19 . The lower part of the box body 4 is equipped with a funnel 18 with a discharge port 15 . The discharge port 15 is located above the feed end of the sorting screen 10, and the discharge end of the sorting screen 10 receives the hopper 11. 1 is an electric control cabinet.

The specific structure of the drum 5 is shown in Fig. 2 and Fig. 3, the whole is cylindrical, the peripheral wall 5-3 is screen-shaped, and has a cover 5-1 that can be opened and closed. In the peripheral wall 5-3, there are evenly three groups of copy board groups that are inclined forward in the direction of rotation. The included angle between the root of each copying board 5-2 and its extension direction is 35°.

The specific structure of the screen is shown in Fig. 4 and Fig. 5. The oblong holes 5-a extending in the circumferential direction are distributed at intervals in the row and axial direction to form a mesh lattice. The long sides on both sides of the oblong hole 5-a are serrated. The geometric centers of the oblong holes 5-a in adjacent rows are staggered, and the rolling edges 5-b formed by punching and drawing in the peripheral wall are distributed at the circumferential interval between the two adjacent rows of oblong holes (see Figure 6 and Figure 7). The punching edge of the blade 5-b is drawn to form an arc edge 5-c. The extension direction of the rolling edge 5-b is substantially perpendicular to the extension direction of the copy plate 5-2. Peripheral wall tangential vertical 5-3.

The specific structure of the copying plate 5-2 is shown in Fig. 8 and Fig. 9, and the surface facing the rotation direction has a row (row direction is the axial direction) convex truncated cones 5-e distributed at intervals. The column spacing d=15mm between adjacent raised circular truncated cones is about 4 times the average particle size of mung bean. The pitches of the raised circular platforms 5-e of adjacent columns are alternately sparse and dense, and the size s1 of the sparse spacing is equal to the column spacing, which is also about 4 times the average particle size of mung bean, and the size s2 of the dense spacing is equal to about 2 times the average particle size of mung bean. times, is 7mm.

When the mung beans are peeled, the following pretreatments are performed first: the first step is to spray the mung beans with 3% sodium chloride brine to a moisture content of 11.5%; Freeze in the environment for at least 5 hours; the third step is to place the frozen mung beans in a microwave environment for intermittent heating, the first heating to 50 ° C, after holding for 1 min, and then flipping for 10 s; the second heating to 50 ° C, holding for 2 minutes The purpose of the second heating is to quickly vaporize the water vapor after the first heating, so that the mung bean skin can be micro-exploded and loosely separated from the bean embryo. Then pour it into the high-efficiency peeling machine and run it for 25-30 minutes to complete the fourth step; that is, lift the top cover and open the cover, put the mung beans to be peeled into the drum, close the cover and the top cover, and start the drum motor first. And the fan, make the mung beans roll in the drum for about 5 minutes, use the rolling blade to initially destroy the mung bean husk, and then start the grinding wheel roller motor, so that the mung beans and the grinding roller are ground and peeled at the same time as the rolling blade, and the fan will take off in time. The bean husk scraps are sucked away, and after about 25 minutes, the machine can be stopped and discharged.

In the above process, the pretreatment can make the mung bean skin layer and the bean embryo form a gap or even peel off, and initially loosen from the bean embryo. Then it is sent to the peeling machine for high-speed flipping and then low-speed grinding. Usually, the drum speed is controlled at about 1000r/min, and the reverse speed of the grinding wheel roller is about 20r/min, so as to ensure that the mung beans are constantly flipped, evenly polished, and are consistent with the rolling edge. Produces constant cutting and peeling. The dense and densely spaced bosses on the copying board can effectively ensure that the mung beans are picked up in the radial direction, and complete the complete friction process between the bean skin and the boss. The friction further loosens the bean skin, which is more conducive to more thorough peeling. Ensure that mung beans do not remain and block during the peeling process. The unique rolling blade structure makes the mung beans "smash" on the cutting edge of the rolling blade during the copying process, so that the cutting edge is inserted between the bean skin and the bean embryo with a high probability, causing prying and tearing of the loose bean skin. Effectively peel off the bean skin. In addition, the serrated edge of the oblong hole enables the bean hulls that cannot be removed in time by the rolling edge during the peeling process to be further scraped by the serrations during discharge, and can be completely removed. The test results correspondingly prove that the peeling time can be shortened by more than 30%, and the peeling qualification rate can be increased by more than 40%.

In a word, this embodiment not only innovates the quasi-dry pretreatment on the basis of in-depth research on the peeling mechanism of mung bean, but also makes a breakthrough from the perspective of the working principle of peeling equipment. Moreover, it can better remove the green skin that cannot be ground in the depression of the mung bean germ, better solve the problem that the mung bean germ cannot be peeled in the depression, improve the peeling qualification rate, and ensure the quality of the bean embryo after the mung bean is peeled and peeled. With the help of "cutting and peeling" combined with "grinding wheel friction", the peeling efficiency, qualified rate and rice yield are significantly improved compared with the traditional single "grinding wheel friction".

In addition to the above-described embodiments, the present invention may also have other embodiments. All technical solutions formed by equivalent replacement or equivalent transformation fall within the protection scope of the present invention.

Claims (7)

1. a method for treating before peeling of mung bean is characterized in that comprising the following steps: The first step is to spray the mung bean with 3±1% sodium chloride aqueous solution to make its moisture content reach 11.5±2%; The second step is to freeze the mung bean after the wet spray treatment for more than 5 hours at -15±2°C; The third step is to intermittently heat the frozen mung beans with microwaves. For the first time, heat to 50±1°C, keep the temperature for 1-1.2min, and then turn it for 10-15s; for the second time, heat it to 50±2°C and keep the temperature for 2- 2.2min; Step 4: Put the microwave-heated mung bean into the mung bean peeling machine, and stop after peeling. 2. the high-efficiency peeling machine that is used for the described mung bean peeling pretreatment method of claim 1, is characterized in that: the top of the frame of this machine supports the rotatable drum that is positioned in the box and the same that is positioned in the drum and the rotation direction is opposite to the drum. Shaft grinding wheel roller; one side of the box is provided with an air inlet, and the lower part is provided with a funnel with a material outlet; The peripheral wall of the drum is evenly spaced with copying plates that are inclined forward in the direction of rotation. The peripheral wall has circumferentially extending oblong holes forming meshes. The oblong holes are distributed in rows along the circumferential direction. interval distribution, forming a lattice distribution; The circumferential interval between the oblong holes in the adjacent rows distributes rolling edges with circular arc edges extending into the peripheral wall. Tangentially perpendicular to the peripheral wall. 3 . The high-efficiency peeling machine according to claim 2 , wherein the rolling edge is formed by punching and drawing, and the punching edge of the rolling edge is drawn to form an arc edge. 4 . 4 . The high-efficiency peeling machine according to claim 3 , wherein the long sides on both sides of the oblong hole are in a zigzag shape, and the geometric centers of the oblong holes in adjacent rows are dislocated. 5 . 5. high-efficiency peeling machine according to claim 4, is characterized in that: the surface of described copying plate toward the rotation direction has rows of raised circular platforms perpendicular to the axial interval distribution, and the row spacing of described raised circular platforms is the average of mung bean 3-5 times the particle size. 6. high-efficiency peeling machine according to claim 5, is characterized in that: described raised circular platform alternately changes according to the regularity of one row sparse interval distribution, the next row dense interval distribution, the size of the sparse interval is equal to the row interval, the size of the dense interval It is 1.5-2.5 times the average particle size of mung bean. 7 . The high-efficiency peeling machine according to claim 1 , wherein the rotating speed of the drum is 1000±50 r/min, and the reverse rotating speed of the grinding wheel is 20±2 r/min. 8 .

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