Processing method of saline-alkaline tolerant preboiled rice

Abstract

The invention discloses a processing method of saline-alkaline tolerant preboiled rice, and belongs to the technical field of preboiled rice processing, and the processing method comprises the following steps: S1, rice screening: removing impurities, and screening out full-grain and mildew-free rice; s2, soaking is conducted, specifically, the screened unhulled rice is soaked, and ultrasonic waves are adopted for assisting in soaking during soaking; s3, steaming and boiling: steaming and boiling the soaked rice; s4, drying: drying the cooked rice until the water content is safe; s5, treatment: husking the dried unhulled rice to obtain brown rice, and then removing husks to finally obtain preboiled rice; and S6, quality selection: screening out the preboiled rice with qualified quality, and packaging and warehousing the preboiled rice. Sectional type drying can be carried out in the drying process, the drying temperature is dynamically adjusted in each stage according to the water content, the change rate, the environment temperature and humidity influence and other factors of unhulled rice, stress concentration in rice grains caused by the too large water gradient can be effectively reduced, and therefore the rice breaking rate is reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of parboiled rice processing, and particularly relates to a processing method of salt-alkali tolerant parboiled rice. Background Art

[0002] Salt-alkali-tolerant rice refers to a special rice variety that can grow and maintain a certain yield in soils with high salinity and alkalinity. Since large amounts of saline-alkali land worldwide are unsuitable for conventional crop cultivation, growing salt-alkali-tolerant rice not only allows these previously abandoned lands to be used for agricultural production but also helps improve soil structure, gradually reducing salt concentrations in the soil and creating conditions for the cultivation of other crops. Parboiled rice, also known as half-cooked rice, is a special type of rice. It is made from rice grains that undergo a series of hydrothermal processes, including soaking, steaming, drying, and slow cooling. After a short period of high-pressure steam, the rice is hulled and milled to create a naturally nutritious and healthy rice. It offers advantages such as high nutritional value, a low glycemic index, a long storage life, and a short cooking time.

[0003] Existing parboiled rice processing generally involves soaking, steaming, drying, and quality selection. During the soaking process, static soaking is often used, which takes a long time and is difficult to control the water temperature during the soaking process. Since salt-alkali-tolerant rice contains a high sodium content, static soaking cannot easily reduce the sodium content, which can easily affect the final quality of the parboiled rice. In addition, the existing parboiled rice drying process generally sets a fixed temperature for drying, and the temperature cannot be adjusted in real time according to the moisture content of the rice. Since the cortex of saline-alkali rice has a high silicon content, the husk becomes more brittle after drying. If the drying temperature is not accurately controlled, the broken rice rate in the later stage will increase, thereby affecting the quality of the finished product. Summary of the Invention

[0004] The object of the present invention is to provide a method for processing salt-alkali tolerant parboiled rice to solve the problems faced in the above-mentioned background technology.

[0005] The purpose of the present invention can be achieved through the following technical solutions: A method for processing salt-alkali tolerant parboiled rice, comprising: S1. Rice screening: Use multi-layer vibrating screens to remove impurities and select rice with full grains and no mold; S2, soaking, soaking the screened rice in water, using ultrasonic wave to assist soaking; S3, steaming, steaming the soaked rice in a sealed container to gelatinize the starch inside the rice; S4, drying, drying the cooked rice in a gradient manner to a safe moisture content; S5, processing, removing the rice husk from the dried rice to obtain brown rice, then passing the rice through a rice mill to remove the outer bran of the brown rice, retaining the germ, and finally obtaining parboiled rice; S6. Quality selection: screen out the parboiled rice of qualified quality and finally pack it for storage.

[0006] Furthermore, the operation method of S2 is: S21, washing the rice twice with 40°C warm water, each washing time being three minutes; S22. Soak the rice in 45°C water for one hour, add 0.5% citric acid solution to the warm water, adjust the pH to 6.0, and turn on the ultrasonic wave. The ultrasonic wave operation mode is: five minutes of operation, ten minutes of pause, and a frequency of 25 kHz. S23, transferring the rice treated in S22 into a vacuum tank for 15 minutes, with gradient pressure treatment for the first 10 minutes and fixed pressure treatment for the last five minutes; S24, soaking the rice after S23 in 45° C. water for another two hours, and adjusting the pH to 6.0. At this time, the ultrasonic operation mode is changed to: working for 10 minutes and pausing for 20 minutes; S25, soaking the rice for one hour at 40°C water temperature, adding 0.1 mol / L calcium lactate solution, and turning off the ultrasound; S26. Take out the soaked rice and drain it through a vibrating sieve.

[0007] Furthermore, the operation method of S2 also includes: monitoring the water temperature and pH value in real time during soaking and adjusting them. The water temperature adjustment method is: installing multiple water temperature detectors in the soaking water, obtaining the water temperature in real time, and thus calculating the average temperature of the soaking water, and judging whether the average temperature is the set soaking water temperature. If not, adjusting the water temperature to the set soaking temperature.

[0008] Furthermore, the operation method of S4 is: S41, sending the cooked rice into a dryer, using medium and low temperature hot air to perform variable temperature drying on the rice, and stopping drying when the moisture content reaches 25%; S42, stacking the dried rice in a warehouse and letting it stand for 2 hours to allow it to slowly recover; S43. Continue drying the slowly reviving rice, and stop drying when the moisture content of the rice reaches 12%.

[0009] Furthermore, in step S43, the moisture content of the rice is detected in real time during the drying process, so as to adjust the drying temperature. The adjustment method is as follows: The drying process is divided into multiple drying stages. In each drying stage, Get the moisture content of rice , determine the moisture content of rice Is it within the preset value range? If the moisture content is not within the preset range, the drying temperature will be adjusted. When the drying temperature is increased, When the drying temperature is low, adjust the drying temperature to low.

[0010] Furthermore, the temperature adjustment method is: when At this time, adjust the drying temperature to , ; when At this time, adjust the drying temperature to , ; In the above formula, as well as is the correction factor, is the conversion factor, The drying temperature set for the current time period.

[0011] Furthermore, the correction coefficient is obtained by: according to The moisture content is obtained in real time within a certain period of time, and the moisture content curve function over time is determined. , and based on historical drying data, determine the control function ; With time as the x-axis and water content as the y-axis, a rectangular coordinate system is constructed, and in the same coordinate system, and The area enclosed between , through the formula Correction factor ; By formula Correction factor ; Where, is the area control value, for The maximum slope, for The minimum slope, is the slope control value, is the weight coefficient, is the ambient temperature, is the ambient temperature reference value, is the ambient humidity, It is the reference value of ambient humidity.

[0012] Furthermore, the operation method of S6 is: S61. Based on big data information, a comprehensive quality screening model Q is constructed. The mathematical expression of the model is: , is the total number of test indicator items, is the parameter value of the i-th detection index, is the ideal parameter value of the i-th detection index, is the weight of the i-th detection index; S62. Obtain multiple test indicators of parboiled rice through relevant equipment, bring them into the comprehensive quality screening model, and derive the quality difference index of the current parboiled rice. ; S63. Set quality screening threshold , filter out the quality difference index less than The steamed rice is packaged and stored.

[0013] Beneficial effects of the present invention: The present invention adopts ultrasonic wave to assist soaking during soaking, which can make water molecules more easily penetrate into the gaps between starch granules and facilitate the transfer of nutrients, thereby effectively shortening the soaking time. In addition, a gradient soaking method is adopted during soaking, so that the soaking is always in a weakly acidic environment, which can not only fully reduce the sodium content of rice, but also increase the calcium content in the finished rice, thereby ensuring the final quality. At the same time, segmented drying can be carried out during the drying process, and the drying temperature can be dynamically adjusted in each stage according to the moisture content, change rate, environmental temperature and humidity of the rice, etc., which can effectively reduce the internal stress concentration of rice grains caused by excessive moisture gradient, thereby reducing the occurrence of broken rice rate, and ensuring product processing efficiency and product quality.

[0014] Of course, any product implementing the present invention does not necessarily need to achieve all of the advantages described above at the same time. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0016] Figure 1 It is a flow chart of the processing method of the present invention. DETAILED DESCRIPTION

[0017] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts shall fall within the scope of protection of the present invention.

[0018] In one embodiment, a method for processing salt-alkali tolerant parboiled rice is disclosed, such as Figure 1 As shown, the processing method mainly includes the following steps: S1. Rice screening: Use multi-layer vibrating screens to remove impurities and select rice with full grains and no mold; S2, soaking, soaking the screened rice in water, using ultrasonic wave to assist soaking; S3, steaming, steaming the soaked rice in a sealed container to gelatinize the starch inside the rice; S4, drying, drying the cooked rice in a gradient manner to a safe moisture content; S5, processing, removing the rice husk from the dried rice to obtain brown rice, then passing the rice through a rice mill to remove the outer bran of the brown rice, retaining the germ, and finally obtaining parboiled rice; S6. Quality selection: screen out the parboiled rice of qualified quality and finally pack it for storage.

[0019] Through the above technical solution, the present application first uses a multi-layer vibrating screen to remove impurities, sand, dust, rice husks, etc., so as to screen out rice with full grains and no mildew, ensuring the purity of the raw materials; then the screened rice is immersed in water for soaking, and ultrasonic assisted soaking is used during the soaking. Through soaking, the rice can fully absorb water, which helps to soften the husk and endosperm, thereby preparing for the subsequent steaming step. The use of ultrasonic soaking during the soaking can accelerate water penetration, shorten the soaking time, and improve the efficiency of nutrient transfer; then the soaked rice is steamed in a sealed container to gelatinize the starch inside the rice. During the steaming process, high temperature and high pressure make the nutrients in the rice husk and endosperm (such as B vitamins, minerals, etc.) can more easily penetrate into the internal endosperm, which not only improves the overall nutritional value of the rice grains, but also makes these beneficial ingredients more evenly distributed in the rice grains, while gelatinizing the starch inside the rice grains, which can improve the taste of the rice grains; the steamed rice is dried in a dryer, and the moisture content of the rice is continuously monitored during the drying process to ensure the final moisture content of the rice, so as to ensure the quality of the later products; after the drying is completed, the dried rice is first passed through a huller to remove the rice husk to obtain brown rice, and then passed through a rice mill to remove the bran on the outer layer of the brown rice, retaining the germ, and finally obtaining parboiled rice; finally, a comprehensive quality screening model is constructed to screen out the parboiled rice of qualified quality, which is finally packaged and put into storage. In this way, ultrasound is used to assist soaking, which can make it easier for water molecules to penetrate into the gaps between starch granules and facilitate the transfer of nutrients, thereby effectively shortening the soaking time. Gradient soaking is used during soaking, which can not only significantly reduce the sodium content of the finished salt-alkali tolerant rice, but also increase the calcium content of the finished rice, thereby ensuring product quality. At the same time, segmented drying can be carried out during the drying process, and the drying temperature can be dynamically adjusted in each stage according to the moisture content, change rate, and environmental temperature and humidity of the rice. This can effectively reduce the internal stress concentration of the rice grains caused by excessive moisture gradients, thereby reducing the occurrence of broken rice rate of salt-alkali tolerant rice and ensuring product processing efficiency and product quality.

[0020] The operation method of S2 is as follows: S21, washing the rice twice with 40°C warm water, each washing time is three minutes; S22. Soak the rice in 45°C water for one hour, add 0.5% citric acid solution to the warm water, adjust the pH to 6.0, and turn on the ultrasonic wave. The ultrasonic wave operation mode is: five minutes of operation, ten minutes of pause, and a frequency of 25 kHz. S23, transferring the rice treated in S22 into a vacuum tank for 15 minutes, with gradient pressure treatment for the first 10 minutes and fixed pressure treatment for the last five minutes; S24, soaking the rice after S23 in 45° C. water for another two hours, and adjusting the pH to 6.0. At this time, the ultrasonic operation mode is changed to: working for 10 minutes and pausing for 20 minutes; S25, soaking the rice for one hour at 40°C water temperature, adding 0.1 mol / L calcium lactate solution, and turning off the ultrasound; S26, taking out the soaked rice and draining it through a vibrating sieve; Among them, the water temperature is monitored and adjusted in real time during soaking. The adjustment method is: multiple water temperature detectors are installed in the soaking water to obtain the water temperature in real time, so as to calculate the average temperature of the soaking water, and judge whether the average temperature is the set soaking water temperature. If not, the water temperature is adjusted to the set soaking temperature. At the same time, steps S22, S24, and S25 also monitor whether the pH value of the soaking water is within the preset range. If not, the pH is adjusted.

[0021] Through the above technical solution, this embodiment provides a specific operation process for soaking rice. First, the rice is pre-treated and cleaned. The rice is washed twice with 40°C warm water, each washing time is three minutes, to remove surface impurities; then, the rice is soaked for one hour at a soaking water temperature of 45°C, and 0.5% citric acid solution is added to the warm water to adjust the pH to 6.0. At the same time, the ultrasonic wave is turned on. The ultrasonic wave operation mode is: work for five minutes, pause for ten minutes, and the frequency is 25kHz. This process is the ultrasonic starting section, which can make the rice grains initially absorb water and the rice grains The cortical micropores expand under the impact of cavitation bubble burst, facilitating the transfer of nutrients. At the same time, adding 0.5% citric acid solution to warm water can create an initial hypertonic environment, thereby shrinking the surface cells to form a protective layer and forming a protective barrier. The treated rice is then transferred to a vacuum tank for 15 minutes. The first 10 minutes are treated with a gradient pressure, 0-3 minutes at -30kPa, 3-6 minutes at -50kPa, 6-10 minutes at -80kPa, and the last five minutes are treated with a fixed pressure to maintain the air pressure at -80kPa. Through this operation, Extract the sodium ions in the cells to facilitate the subsequent reduction of sodium ions, and use gradient pressure reduction to make the osmotic pressure drop slowly, avoid sudden expansion and rupture of cells, and reduce the occurrence of rice cracking rate; then soak the treated rice in 45℃ water temperature for two hours, and adjust the pH to 6.0. At this time, change the ultrasonic operation mode to: work for ten minutes and pause for twenty minutes. This process is the ultrasonic enhancement section. During this period, the hardness of the rice grains can be tested every half an hour to ensure that the cortex is softened evenly, while avoiding excessive water absorption of the endosperm caused by long-term ultrasound. At the same time, in a weakly acidic environment, it can not only provide sufficient The rice is then soaked in 40°C water for one hour, with a 0.1 mol / L calcium lactate solution added and ultrasound turned off. This stage is the static water absorption phase, allowing the rice grains to absorb water in an undisturbed environment to ensure uniform moisture content while simultaneously replacing sodium ions. This not only removes excess sodium in sea rice but also provides sufficient calcium ions to improve product quality. Finally, the soaked rice is removed and drained through a vibrating screen. This method uses ultrasound to vibrate at high frequencies in the water during the soaking process, forming cavitation bubbles. When the bubbles burst, they release energy, impacting the rice grain surface and destroying the dense structure of the cortex and endosperm. This allows water molecules to more easily penetrate the gaps between starch granules, facilitating nutrient transfer and effectively shortening the soaking time. At the same time, ultrasound can induce liquid microflow, which drives the rice grains to flip and evenly contact the water medium, avoiding uneven water absorption caused by local accumulation and ensuring consistent gelatinization during subsequent cooking. Through this operation, compared with ordinary soaking in water, the functional component retention rate of the steamed rice during the soaking process is greater than 85%. At the same time, a large amount of sodium ions can be replaced, so that the sodium content of the steamed rice is less than 50mg / 100g, and the crack rate is also greatly reduced.

[0022] At the same time, the water temperature and pH value are monitored and adjusted in real time during the entire soaking process. Specifically, multiple water temperature detectors can be installed in the soaking water to obtain the water temperature in real time, so as to calculate the average temperature of the soaking water and determine whether the average temperature is the set soaking water temperature. If not, the water temperature is adjusted to the set soaking temperature. This can keep the water temperature in a balanced environment to ensure the stability of the water absorption rate. The method for adjusting the pH is that, in a weakly acidic environment, sodium ion replacement can be better promoted, thereby better performing sodium reduction operations. Therefore, it is necessary to ensure that the pH value is within a certain range. Therefore, in each soaking process, multiple adjustment time points are set, and the soaking area is divided into multiple monitoring areas. First, the pH value of each monitoring area is obtained at the adjustment time point to determine whether it is within the predetermined range. If so, no adjustment is made. If not, the pH value is adjusted to the optimal pH point within the predetermined range. Then, when it is determined that no pH adjustment is required, the formula Calculate the deviation value of each monitoring area ,in, is the number of monitoring areas, The last adjustment time point, Adjust the current time point. is the monitoring area in the i-th The pH value changes with time curve function, formula Indicated in The difference between the pH value of a single monitoring area and the pH value of the entire monitoring area within a certain time period, and the formula It represents the difference between the pH value of a single monitoring area and the pH value of the entire monitoring area at the current adjustment time point. Therefore, the formula Combined with the historical difference between the last adjustment time point and the current adjustment time point, a comprehensive analysis is conducted to determine the pH value change risk of each test area. Obviously, if the deviation value The larger the pH value, the greater the difference between the monitored area and the overall pH value, and the greater the potential risk of abnormal pH value deviation. Therefore, a deviation judgment threshold is set based on empirical data. ,when When the pH value of the monitoring area is detected, it is locked and directly adjusted to the optimal pH point within the predetermined range. In this way, the potential risk of abnormal pH deviation can be judged according to the deviation value of each monitoring area, so that the pH value can be adjusted in time to ensure that the immersion is always in the optimal weak acid environment, which is conducive to the removal of sodium.

[0023] Table 1 Immersion index comparison table

[0024] The experimental data, as shown in Table 1, show that ultrasonic-assisted soaking can increase the whole rice rate by 8%, the cortex nutrient transfer rate by 9%, the time cost by 50%, and the sodium content by significantly reducing compared with ordinary soaking because there is no mechanical stirring damage.

[0025] S3. Steaming: Steam the soaked rice in a sealed container to gelatinize the starch inside the rice. During the steaming process, use micro-pressure (0.1-0.15 MPa) steam for 15-25 minutes to shorten the steaming time and reduce the damage to heat-sensitive functional components.

[0026] The operation method of S4 is as follows: S41, sending the cooked rice into the drying machine, using medium and low temperature hot air to perform variable temperature drying on the rice, and stopping the drying when the moisture content reaches 25%; S42, stacking the dried rice in a warehouse and letting it stand for 2 hours to allow it to slowly recover; S43, continue drying the slowly reviving rice, and stop drying when the moisture content of the rice reaches 12%; Step S43: During the drying process, the moisture content of the paddy is also detected in real time, so as to adjust the drying temperature. The adjustment method is as follows: the drying process is divided into multiple drying stages, and in each drying stage, the moisture content of the paddy is adjusted at intervals. Get the moisture content of rice , determine the moisture content of rice Is it within the preset value range? If the moisture content is not within the preset range, the drying temperature will be adjusted. When the drying temperature is increased, When the drying temperature is too low, when At this time, adjust the drying temperature to , ; when At this time, adjust the drying temperature to , ; In the above formula, as well as is the correction factor, is the conversion factor, The drying temperature set in the current time period; the correction coefficient is obtained by: The moisture content is obtained in real time within a certain period of time, and the moisture content curve function over time is determined. , and based on historical drying data, determine the control function ; With time as the x-axis and water content as the y-axis, a rectangular coordinate system is constructed, and in the same coordinate system, and The area enclosed between , through the formula Correction factor ; By formula Correction factor ; Where, is the area control value, for The maximum slope, for The minimum slope, is the slope control value, is the weight coefficient, is the ambient temperature, is the ambient temperature reference value, is the ambient humidity, It is the reference value of ambient humidity.

[0027] The above scheme provides the specific steps of the drying process. Before drying, desalinated circulating water is used for rapid cooling and rinsing, and then the rice is sent to the dryer. Medium and low temperature hot air is used to perform variable temperature drying on the rice. The variable temperature can be 40 degrees at the beginning, then 60 degrees at the middle temperature, and finally dried at 45 degrees. Water is locked at 40 degrees, shaped at 60 degrees, and finally balanced at 45 degrees. This gradient temperature drying can not only ensure uniform moisture content, but also reduce the crack rate and increase the whole rice rate. Drying is stopped after the moisture content reaches 25%. This can quickly reduce the moisture on the surface of the rice and avoid long-term high temperature causing rice to crack. Grains are cracked or over-gelatinized, and the whole rice rate is increased; the dried rice is then piled in a warehouse and left to stand for 2 hours for slow thawing. This process allows the moisture inside the rice to diffuse evenly, reduces the internal and external moisture gradient, and reduces the drying crack rate. The slow-thawing rice is then dried again, and the drying is stopped after the moisture content of the rice reaches 12%. During the drying process, the moisture content of the rice is detected in real time, so that the drying temperature is adjusted. Segmented drying is used, and the temperature is dynamically adjusted according to the moisture content to reduce the internal stress concentration of the rice grains caused by excessive moisture gradients, thereby reducing the occurrence of broken rice rate and ensuring product processing efficiency and product quality. The specific adjustment method is: divide the drying process into multiple drying stages, and in each drying stage, every once in a while Get the moisture content of rice , determine the moisture content of rice Is it within the preset value range? If the moisture content is not within the preset range, the drying temperature will be adjusted. , then increase the drying temperature. , ,when , then lower the drying temperature. At this time, adjust the drying temperature to , Since each drying stage has a corresponding moisture gradient, the gradient cannot be too large or too small, so the moisture content of the rice is obtained at intervals. , judge whether the water content is within the corresponding predetermined gradient range. If it is not within the predetermined gradient range, it means that the water content is abnormal and needs to be adjusted. When , it means that the moisture content of the rice is higher than the standard moisture content, so the drying temperature needs to be increased. The specific formula is: Make adjustments; otherwise, When , it means that the moisture content of the rice is lower than the standard moisture content, and the water loss rate is too fast, then it is necessary to lower the drying temperature to delay the loss of water. The specific formula is: Adjust the conversion factor in the formula The drying temperature set in the current time period can be determined based on the control experiment It is determined based on historical data.

[0028] The temperature adjustment is not only related to the moisture content, but also to the temperature, humidity, and moisture content change rate. For example, when the ambient humidity in the processing area is too high, the temperature needs to be increased appropriately to compensate for the moisture absorption effect. When the ambient temperature in the processing area is too low, the temperature also needs to be increased appropriately to ensure normal drying efficiency. Therefore, the formula as well as Correction factor 、 , put it into the formula to more accurately adjust the drying temperature to ensure the normal moisture content of rice at each stage. is the area control value, is the slope control value, is the ambient humidity control value, is the ambient temperature control value, which can be determined based on the control experiment, and the weight coefficient Based on experience, it can be assumed that the ambient humidity and ambient temperature are obtained through the corresponding sensors installed in the processing area, and the default values ​​are positive; from the formula It can be seen that when the drying temperature needs to be increased, Represents the function and The difference between the two values ​​is as follows: the larger the value, the The greater the moisture content within the time period is compared to the standard moisture content, the greater the increase required. The formula Indicates the rate of change. The larger the value, the higher the The slower the moisture content changes within a certain time, the more the drying temperature needs to be increased. Similarly, when the ambient humidity is higher or the ambient temperature is lower, the more the drying temperature needs to be increased. Therefore, the correction coefficient The correction can more accurately increase the temperature; from the formula It can be seen that when the drying temperature needs to be lowered, Represents the function and The difference between the two values ​​is as follows: The greater the moisture content within the time period is compared to the standard moisture content, the more the temperature needs to be lowered. The larger the value, the faster the rate of change, and the more the temperature needs to be lowered. Similarly, when the ambient temperature is higher or the ambient humidity is lower, the more the temperature needs to be lowered. Therefore, the correction coefficient is used to This method allows for segmented drying during the drying process, dynamically adjusting the drying temperature at each stage based on the rice's moisture content, rate of change, and the effects of ambient temperature and humidity. This effectively reduces stress concentration within the rice grains caused by excessive moisture gradients, thereby reducing the incidence of broken rice and ensuring processing efficiency and quality.

[0029] The operation method of S6 is: S61. Based on big data information, a comprehensive quality screening model Q is constructed. The mathematical expression of the model is: , is the total number of test indicator items, is the parameter value of the i-th detection index, is the ideal parameter value of the i-th detection index, is the weight of the i-th detection index; S62. Obtain multiple test indicators of parboiled rice through relevant equipment, bring them into the comprehensive quality screening model, and derive the quality difference index of the current parboiled rice. ; S63. Set quality screening threshold , filter out the quality difference index less than The steamed rice is packaged and stored.

[0030] The above technical solution provides a specific method for quality selection of parboiled rice. First, based on the information of big data, a neural network model is used for training to construct a comprehensive quality screening model Q. The mathematical expression of the model is: , is the total number of test indicator items, is the parameter value of the i-th detection index, is the ideal parameter value of the i-th detection index, is the weight of the i-th detection index, and then multiple detection indicators of parboiled rice are obtained through relevant equipment, brought into the comprehensive quality screening model, and the quality difference index of the current parboiled rice is obtained , and set the quality screening threshold , filter out the quality difference index less than The parboiled rice is packaged and put into storage; for example, the cracking rate of rice grains is obtained through the image recognition system, the moisture content of rice grains is obtained through the microwave moisture meter, and the color value of rice grains is obtained through the colorimeter. These test indicators are brought into the comprehensive quality screening model Q and compared with the ideal parameter values ​​of each test indicator to obtain the quality difference index of the parboiled rice. The smaller the value, the better the quality. Therefore, a quality screening threshold is set based on experience. , filter out the quality difference index less than The parboiled rice is packaged and put into storage. This method can be used to conduct a comprehensive analysis based on multiple testing indicators to more accurately test the quality of the parboiled rice, thereby ensuring the quality of the product packaging.

[0031] The present invention adopts ultrasonic assisted soaking + acidic environment gradient soaking during soaking, which not only makes it easier for water molecules to penetrate into the gaps between starch granules, but also facilitates the transfer of nutrients, thereby effectively shortening the soaking time, and at the same time can fully reduce the sodium content of rice, and can also increase the calcium content in the finished rice, thereby ensuring the final quality of the finished product; at the same time, during the soaking process, the pH value of the soaking water is monitored by dividing the soaking area into multiple monitoring areas, which can not only adjust the pH value of the monitoring area with obvious abnormalities, but also adjust the pH value of the monitoring area with potential pH abnormalities, so that the pH abnormality can be discovered in time to ensure that all monitoring areas The pH value is in a highly consistent environment, which is conducive to sodium removal; in the drying process, the present application adopts segmented drying, and dynamically adjusts the drying temperature in each stage according to the moisture content, change rate, environmental temperature and humidity of the rice, etc., which can effectively reduce the internal stress concentration of the rice grains caused by excessive moisture gradient, thereby reducing the occurrence of broken rice rate, ensuring product processing efficiency and product quality; when selecting the quality of steamed rice, the present invention can construct a comprehensive quality screening model based on a comprehensive analysis of multiple detection indicators of steamed rice, thereby obtaining the quality difference index of the current steamed rice, and detecting the quality of the steamed rice according to the quality difference index to ensure the quality of the product packaging.

[0032] It should be noted that, in order to facilitate analysis and calculation, the parameters in the above mathematical formulas are dimensionless operations performed after selecting units, and the dimensionless processing method can be processed through existing technologies such as normalization processing methods, which will not be described in detail here.

[0033] The above content is merely an example and explanation of the concept of the present invention. Those skilled in the art may make various modifications or additions to the described specific embodiments or replace them in a similar manner. As long as they do not deviate from the concept of the invention or exceed the scope defined by the claims, they should all fall within the scope of protection of the present invention.

Claims

1. A method for processing salt-alkali tolerant parboiled rice, characterized in that: The processing method comprises: S1. Rice screening: Use multi-layer vibrating screens to remove impurities and select rice with full grains and no mold; S2, soaking, soaking the screened rice in water, using ultrasonic wave to assist soaking; S3, steaming, steaming the soaked rice in a sealed container to gelatinize the starch inside the rice, using 0.12 MPa micro-pressure steam for 20 minutes; S4, drying, drying the cooked rice in a gradient manner to a safe moisture content; S5, processing, removing the rice husk from the dried rice to obtain brown rice, then passing the rice through a rice mill to remove the outer bran of the brown rice, retaining the germ, and finally obtaining parboiled rice; S6. Quality selection: screen out the parboiled rice of qualified quality and finally pack it for storage.

2. The method for processing salt-alkali tolerant parboiled rice according to claim 1, characterized in that: The operation method of S2 is: S21, washing the rice twice with 40°C warm water, each washing time being three minutes; S22. Soak the rice in 45°C water for one hour, add 0.5% citric acid solution to the warm water, adjust the pH to 6.0, and turn on the ultrasonic wave. The ultrasonic wave operation mode is: five minutes of operation, ten minutes of pause, and a frequency of 25 kHz. S23, transferring the rice treated in S22 into a vacuum tank for 15 minutes, with gradient pressure treatment for the first 10 minutes and fixed pressure treatment for the last five minutes; S24, soaking the rice after S23 in 45° C. water for another two hours, and adjusting the pH to 6.

0. At this time, the ultrasonic operation mode is changed to: working for 10 minutes and pausing for 20 minutes; S25, soaking the rice for one hour at 40°C water temperature, adding 0.1 mol / L calcium lactate solution, and turning off the ultrasound; S26. Take out the soaked rice and drain it through a vibrating sieve.

3. The method for processing salt-alkali tolerant parboiled rice according to claim 2, wherein: The operation method of S2 also includes: monitoring the water temperature and pH value in real time during soaking and adjusting them. The water temperature adjustment method is: installing multiple water temperature detectors in the soaking water, obtaining the water temperature in real time, thereby calculating the average temperature of the soaking water, and judging whether the average temperature is the set soaking water temperature. If not, adjusting the water temperature to the set soaking temperature.

4. The method for processing salt-alkali tolerant parboiled rice according to claim 1, wherein: The operation method of the S4 is as follows: S41, sending the cooked rice into a dryer, using medium and low temperature hot air to perform variable temperature drying on the rice, and stopping drying when the moisture content reaches 25%; S42, stacking the dried rice in a warehouse and letting it stand for 2 hours to allow it to slowly recover; S43. Continue drying the slowly reviving rice, and stop drying when the moisture content of the rice reaches 12%.

5. The method for processing salt-alkali tolerant parboiled rice according to claim 4, characterized in that: In step S43, during the drying process, the moisture content of the rice is also detected in real time, so as to adjust the drying temperature. The adjustment method is as follows: The drying process is divided into multiple drying stages. In each drying stage, Get the moisture content of rice , determine the moisture content of rice Is it within the preset value range? If the moisture content is not within the preset range, the drying temperature will be adjusted. When the drying temperature is increased, When the drying temperature is low, adjust the drying temperature to low.

6. The method for processing salt-alkali tolerant parboiled rice according to claim 5, characterized in that: The temperature adjustment method is: when At this time, adjust the drying temperature to , ; when At this time, adjust the drying temperature to , ; In the above formula, as well as is the correction factor, is the conversion factor, The drying temperature set for the current time period.

7. The method for processing salt-alkali tolerant parboiled rice according to claim 6, characterized in that: The correction coefficient is obtained by: according to The moisture content is obtained in real time within a certain period of time, and the moisture content curve function over time is determined. , and based on historical drying data, determine the control function ; With time as the x-axis and water content as the y-axis, a rectangular coordinate system is constructed, and in the same coordinate system, and The area enclosed between , through the formula Correction factor ; By formula Correction factor ; Where, is the area control value, for The maximum slope, for The minimum slope, is the slope control value, is the weight coefficient, is the ambient temperature, is the ambient temperature reference value, is the ambient humidity, It is the reference value of ambient humidity.

8. The method for processing salt-alkali tolerant parboiled rice according to claim 7, characterized in that: The operation method of the S6 is as follows: S61. Based on big data information, a comprehensive quality screening model Q is constructed. The mathematical expression of the model is: , is the total number of test indicator items, is the parameter value of the i-th detection index, is the ideal parameter value of the i-th detection index, is the weight of the i-th detection index; S62. Obtain multiple test indicators of parboiled rice through relevant equipment, bring them into the comprehensive quality screening model, and derive the quality difference index of the current parboiled rice. ; S63. Set quality screening threshold , filter out the quality difference index less than The steamed rice is packaged and stored.

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