Processing method for improving cooking characteristics of coarse cereals and detection method thereof

Abstract

According to the processing method for improving the cooking characteristics of the coarse cereals, physical and chemical changes required by part of the cooking process are completed in advance through microwave pre-cooking, and a targeted pre-cooking process is set for different types of coarse cereals according to the characteristics of the different types of coarse cereals; therefore, the purpose of simultaneously cooking and cooking different types of coarse cereals and rice can be achieved when the coarse cereals and the rice are mixed and cooked; meanwhile, due to the change of the internal structure of the coarse cereals, the heat input required in the cooking process is correspondingly reduced, so that the cooking efficiency is improved, the processing energy consumption of the coarse cereals is reduced, and the purposes of energy conservation and environmental protection are achieved; on the other hand, the internal structure and the moisture state of the coarse cereals are changed through a microwave pre-curing technology, so that the cooking process becomes easier and more efficient; the technology not only improves the convenience of mixed cooking of the coarse cereals and the rice, but also reduces the energy consumption, and the invention also provides the method for detecting the cooking characteristics of the coarse cereals, which has important significance for promoting the sustainable development of the coarse cereal processing industry.

Description

Technical Field

[0001] The invention relates to the technical field of deep processing of agricultural products, and in particular to a processing method for improving the cooking characteristics of grains and a detection method thereof. Background Art

[0002] Coarse grains refer to the general term for other minor grain and bean crops other than major grain crops such as corn, rice, soybeans, wheat and potatoes, including brown rice, sorghum, red beans, cowpeas, mung beans, black beans, millet, chickpeas, etc. Coarse grains are rich in nutritional value and have a satiety function. They contain a variety of bioactive compounds, such as unsaturated fatty acids, dietary fiber, vitamins, steroids, alkaloids and polyphenols, etc. They are a good source of staple food and have become the key to improving the quality of diet. They can enrich the nutritional components of rice and significantly enhance the nutritional value and health benefits of rice through balanced complementarity and synergistic enhancement. However, due to the presence of cortex and embryo, coarse grains cannot be cooked and cooked with rice when mixed with rice. In addition, in terms of standardization, the coarse grain industry has a series of problems such as the difficulty of achieving standardization in the production process, the low degree of standardization of enterprise production, and the lack of product standardization. The standards for the processing, packaging, and testing of coarse grain products are seriously insufficient, making it difficult to achieve product standardization and the product quality cannot be guaranteed. Therefore, establishing a complete standardization system for the coarse grain industry has become an urgent problem to be solved.

[0003] Traditional grain processing techniques, such as soaking, frying, baking, steaming and sand frying, are widely used but have some significant defects. These methods usually have complex process flows, are time-consuming, and are prone to cause a large loss of nutrients during processing, accompanied by high energy consumption. In addition, these traditional methods have limited effects on the fiber structure of grains, especially the cortex and cell structure, making it difficult to effectively improve the cooking characteristics of grains. Since different varieties of grains have their own unique physical and chemical properties, traditional heat treatment methods cannot meet the needs of enterprises for establishing a unified quality standard system and operating procedures, which limits their application and development in large-scale production.

[0004] Since microwaves act on materials by volumetric heating, molecular friction and vibration are caused by high-frequency electromagnetic waves, so that energy is converted into heat energy, thereby heating the materials, which has the advantages of energy saving, short processing time, economical operating cost, and maximum retention of the nutritional components of food. For example, the patent document with publication number CN113679000A discloses a microwave rapid ripening method for coarse grains such as black rice, brown rice, red rice, purple rice, coix seeds, barley, oats, black beans, red beans, mung beans, kidney beans, green beans, lentils, chickpeas, etc. Although this technology can achieve a rapid ripening effect, this technology does not detect the degree of gelatinization. For coarse grains with different grain structures, such as black rice and black beans, there are significant differences in physical and chemical properties and grain size. Under the same technical processing conditions, the phenomenon of excessive gelatinization of coarse grains will occur seriously, which greatly destroys the edible and nutritional quality of coarse grains. The energy loss in the micro-opening stage of grain processing (microwave power 25 kW, monitoring temperature set 80-140 °C, processing time 2-10 min; drying stage: power 15 kW, monitoring temperature set 50-80 °C, processing time 2-20 min) is about 4.8 × 10 6 J-3.3×10 7 J, which makes the energy consumption of each grain processing process inaccurate, the processing cost is high, and it cannot effectively guide the production of enterprises. The patent document with publication number CN 118044586 A discloses a kind of easy-to-cook nutritious grain rice and its preparation method, which includes the following steps: raw material selection, low temperature treatment, endogenous enzyme activation, pre-cooking, drying, blending and packaging, wherein the low temperature treatment temperature is -20-4℃, and the processing time is 2-15h, which makes the processing process energy-intensive, the processing cost is high, the processing cycle is long, and it is not easy to promote.

[0005] Currently, grain products with different degrees of maturity can be obtained through microwave processing technology, but there is no targeted pre-cooking process based on the characteristics of different types of grains, resulting in the inability to achieve the same cooking effect when different types of grains are mixed with rice. At the same time, due to the lack of standard detection methods, the grain pre-cooking processing methods in the existing technology are not conducive to combining with standardized production, and there are problems such as high energy consumption in the processing process, changes in product appearance and edible characteristics, and products that are not conducive to storage and transportation. Summary of the invention

[0006] In view of the shortcomings of the prior art, the first aspect of the present invention provides a processing method for improving the cooking characteristics of grains, which solves the problems in the prior art that different types of pre-cooked grains cannot be cooked together with rice, as well as the problems of high energy consumption in the processing process, changes in the appearance and edible characteristics of the product, and the product being difficult to store and transport.

[0007] To achieve the above object, the present invention adopts the following technical solutions: In one aspect, the present invention provides a processing method for improving the cooking properties of grains, comprising the following steps: Step 1: Raw material preparation and screening: remove solid impurities, foreign grains, imperfect grains and broken grains from the grains; Step 2: Raw material pretreatment: wash and drain the selected grains; Step 3: Constant temperature soaking: Soak the pre-treated grains in a constant temperature water bath; Step 4: using microwaves to perform differential pre-cooking treatment on the grains soaked at constant temperature: drying the grains soaked at constant temperature and transferring them to a microwave device, spreading the grains into a material layer with uniform thickness; calculating the weight per unit area of ​​the material layer according to the grain size and 100-grain weight of the grains, and determining the number of microwave heating times according to the weight per unit area of ​​the material layer; When the weight per unit area of ​​the material layer is 0.25-0.35 g / cm 2 When the microwave frequency is set to 6 times; When the weight per unit area of ​​the material layer is 0.35-0.45g / cm 2 When the microwave frequency is set to 7 times; When the weight per unit area of ​​the material layer is 0.45-0.55g / cm 2 , set the microwave times to 8 times.

[0008] Step 5: Packaging and storage of finished products: Drain the moisture from the microwave pre-cooked grains, quickly vacuum-seal and package them, and store them at room temperature.

[0009] Preferably, in step three, the constant temperature soaking process is: placing the pretreated grains in a constant temperature water bath at 40° C. and soaking for 2 h at a material-to-water ratio of 1:3.

[0010] Preferably, in step 4, each microwave heating time is 30 seconds and the time interval is 30 seconds.

[0011] Preferably, in step one, the selected grains are one of chickpeas, cowpeas, mung beans, black beans and brown rice, and weigh 60 g; in step four, the material layer thickness is 10 mm, the number of microwave heating times of chickpeas, cowpeas, mung beans, black beans and brown rice is set to 7 times, 6 times, 8 times, 8 times and 6 times respectively, and the microwave heating power is set to 160 W ~ 800 W.

[0012] Preferably, in step 4, the microwave power is set to 480W.

[0013] The second aspect of the present invention provides a method for detecting the cooking characteristics of grains, which provides clear guidance for the pre-cooking process and subsequent steaming process of grains.

[0014] The detection method detects the cooking characteristics of the grains processed by the processing method of the present invention, and the cooking characteristics detection includes the optimal cooking time test, gelatinization degree test, scanning electron microscope observation and energy consumption test; The optimal cooking time test is to cook the cereals processed by the processing method of the present invention, adopt the glass plate white core method, and record the time when all the cereal grains have no white core as the optimal cooking time.

[0015] The gelatinization degree detection is to steam the grains processed by the processing method of the present invention, and use the saccharifying enzyme method to detect the gelatinization degree of the steamed grains; The scanning electron microscope observation is to use a scanning electron microscope to observe the grains processed by the processing method of the present invention, and observe the morphological changes of the seed coat and cotyledons of the grains; The energy consumption test records the energy consumption of constant temperature soaking, microwave pre-cooking, and steaming of the grains when the grains are processed using the processing method of the present invention, and obtains the total energy consumption required for complete cooking of the grains.

[0016] Preferably, the optimal cooking time test comprises the following process: 1) Add 250 mL of water into a 500 mL beaker and heat it to boiling in a water bath on an induction cooker; 2) Weigh 60 g of the grains processed by the processing method of the present invention and pour them into a beaker and start timing. After 15 minutes, take out at least 10 grains of grains every 1 minute, squeeze them with a glass plate, and observe whether the rice grains have a white core. If there is no white core, it means that the grains are cooked; 3) The time when all rice grains have no white core is the optimal steaming time.

[0017] Preferably, the gelatinization degree detection of the cooked grains by using the saccharifying enzyme method comprises the following process: 1) Take 60 g of the processed grains and 120 mL of distilled water and add them to an electric rice cooker for cooking for 30 min. Put the cooked grains into a 45 ℃ electric heating blast drying oven for drying for 12 h, take them out, crush them and sieve them for later use; 2) Weigh 1.00 g of the sample obtained in step 1) and place it in two 100 mL conical flasks, labeling them A and B respectively. 1 , A 2 , take another 100 mL flask without sample as blank, mark it B, and add 50 mL of distilled water to each of the three flasks. 1 Boil on a hotplate or in a boiling water bath for 20 min, then 1 The flask was cooled to room temperature; 2) In A 1 , A2 Add 1 mL of 1% saccharifying enzyme solution (prepare it when needed) to each of the three conical flasks A and B, shake them in a 60 ℃ water bath for 1 h, then add 2 mL of 1 mol / L hydrochloric acid to the three conical flasks to inactivate the enzyme, transfer them to a 100 mL volumetric flask, make up to volume with distilled water, and use them as the test solution after filtering; 3) Take 10 mL of the test solution and place them in three 100 mL ground-mouth Erlenmeyer flasks with stoppers. Add 10 mL of 0.05 mol / L iodine solution and 18 mL of 0.1 mol / L sodium hydroxide solution, then stopper and place in a dark place for 15 min. After standing, add 2 mL of 10% sulfuric acid to each of the three Erlenmeyer flasks and titrate with 0.1 mol / L sodium thiosulfate until the blue color becomes lighter. Add 1 mL of starch indicator and continue titrating until it becomes colorless and remains unchanged for 1 min. Record the number of milliliters of sodium thiosulfate consumed in each flask; obtain: Among them, V 0 V is the volume of sodium thiosulfate consumed in the titration blank. 1 The volume of sodium thiosulfate consumed to titrate the completely gelatinized sample, V 2 Volume of sodium thiosulfate consumed to titrate the sample.

[0018] Preferably, the process of the scanning electron microscope observation is: 1) Soak the sample particles in 3% (v / v) glutaraldehyde to physically harden the surface of the coating; 2) Rinse the sample particles several times with 0.1 M phosphate buffer, then soak them in 1% osmium tetroxide at 4 °C, use ethanol gradient elution five times, and then dry them using the critical point drying method; 3) Coat the sample with ion sputtering, observe with a scanning electron microscope, and take photos.

[0019] Preferably, the energy consumption test includes the following process: 1) Use a power meter to record the energy E consumed by the grains during the constant temperature soaking process in the processing method of the present invention. 浸泡 : E 浸泡 =P 加热 × t 加热 + P 维持 × t 维持 ; Where P 加热 is the heating power of grains during soaking, t 加热 is the heating time; P 维持 The power required to maintain a constant temperature during the soaking process of grains, t 维持 Time to maintain constant temperature; 2) Use a power meter to record the energy E consumed by the grains during the microwave pre-cooking process in the processing method of the present invention. 微波 : E 微波 =P 微波 × t 微波 ; Among them, P 微波 is the microwave heating power, t 微波 Microwave heating time; 3) Use a power meter to record the energy E consumed by the grains processed by the processing method of the present invention during the cooking process. 蒸煮 : E 蒸煮 =P 蒸煮 × t 蒸煮 ; Where P 蒸煮 is the average power of the cooking process, t 蒸煮 is the cooking time; 4) Obtain the total energy consumption E required for the complete ripening of grains 总 =E 浸泡 +E 微波 +E 蒸煮 .

[0020] Beneficial effects: 1. The present invention adopts microwave technology for pre-cooking treatment, and optimizes the microwave heating times and power parameters according to the characteristics of different grains, so as to ensure that different grains can be cooked together with rice.

[0021] 2. The present invention changes the internal structure and moisture state of the grains through microwave pre-cooking technology, making the cooking process easier and more efficient, which not only improves the processing efficiency of the grains but also reduces the processing energy consumption.

[0022] 3. The present invention optimizes the microwave heating times for different types of grains, thus avoiding excessive gelatinization during the pre-cooking process.

[0023] 4. The present invention provides a method for detecting the cooking characteristics of grains, which provides clear guidance for the pre-cooking processing and subsequent steaming process of grains, and is conducive to promoting the standardized production of grains. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 The optimal cooking time for five kinds of grains after microwave pre-cooking; Figure 2 It is the degree of gelatinization of rice and five kinds of grains after direct cooking; Figure 3 The effect of microwave power on the gelatinization degree of five kinds of cereals; Figure 4These are scanning electron micrographs of cotyledons and seed coats of cereals treated with different microwave powers. DETAILED DESCRIPTION

[0025] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. 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 creative work are within the scope of protection of the present invention.

[0026] In the present invention, a processing method for improving the cooking properties of grains comprises the following steps: Step 1: Raw material preparation and screening: remove solid impurities, foreign grains, imperfect grains and broken grains from the grains; Step 2: Raw material pretreatment: wash and drain the selected grains; Step 3: Constant temperature soaking: Soak the pre-treated grains in a constant temperature water bath; Step 4: using microwaves to perform differential pre-cooking treatment on the grains soaked at constant temperature: drying the grains soaked at constant temperature and transferring them to a microwave device, spreading the grains into a material layer with uniform thickness; calculating the weight per unit area of ​​the material layer according to the grain size and 100-grain weight of the grains, and determining the number of microwave heating times according to the weight per unit area of ​​the material layer; When the weight per unit area of ​​the material layer is 0.25-0.35 g / cm 2 When the microwave frequency is set to 6 times; When the weight per unit area of ​​the material layer is 0.35-0.45g / cm 2 When the microwave frequency is set to 7 times; When the weight per unit area of ​​the material layer is 0.45-0.55g / cm 2 , set the microwave times to 8 times.

[0027] Step 5: Finished product packaging and storage: Drain the water from the microwave pre-cooked grains, quickly vacuum seal and package them, and store them at room temperature; In order to make the direct gelatinization degree of each grain close to that of rice (94.05%) and achieve the purpose of cooking and maturing at the same time as rice, microwave was used to perform differential pre-cooking treatment on them: the grains soaked at constant temperature were dried (60 g) and transferred to the microwave equipment with a material layer thickness of 10 mm and a microwave power of 160 W~800 W. According to the differences in grain size and 100-grain weight of the grains, such as: the size of chickpea grains is 1.1 cm×0.9 cm, and the 100-grain weight is 38 g; the size of cowpea grains is 0.6 cm×0.9 cm, and the 100-grain weight is 19 g; the size of mung bean grains is 0.4 cm×0.5 cm, and the 100-grain weight is 10.7 g; the size of black beans is 0.5 cm×0.7 cm, and the 100-grain weight is 17 g; the size of brown rice grains is 0.2 cm×0.4 cm, and the 100-grain weight is 2.1 g. The weight per unit area of ​​grain raw materials such as chickpeas, cowpeas, mung beans, black beans, and brown rice is calculated to be approximately: 0.38g / cm2, 0.35g / cm2, 0.53g / cm2, 0.45g / cm2, and 0.26g / cm2. When the weight per unit area is 0.25-0.35 g / cm2, the number of microwaves is 6 times; when the weight per unit area of ​​grains is 0.35-0.45g / cm2, the number of microwaves is 7 times; when the weight per unit area of ​​grains is 0.45-0.55g / cm2, the number of microwaves is 8 times; the greater the weight per unit area of ​​grains, the more microwaves are used, so the number of microwave heating times is set to 6-8 times.

[0028] Example 1: Chickpeas pretreated at 160 W microwave power were prepared according to the following steps: Step (1), material preparation and screening: screen and accurately weigh 60 g of chickpeas to ensure that the raw materials are fresh.

[0029] Step (2), washing the grains: the chickpeas weighed in step (1) are thoroughly washed to remove impurities, dust and dirt attached to the surface to ensure the cleanliness of the chickpeas.

[0030] Step (3), soaking of grains: Soak the washed grains in a 40°C constant temperature water bath for 2 h at a material-water ratio of 1:3 (i.e., 1 part chickpeas to 3 parts water). This process is intended to allow the chickpeas to fully absorb water and soften their tissue structure in preparation for subsequent microwave pre-cooking.

[0031] Step (4), microwave pre-cooking treatment: transfer the chickpeas after constant temperature soaking to a microwave device, set the microwave power to 160 W, the microwave frequency to 30 s / time, and the number of microwaves to 7 times. The penetration and heating uniformity of microwaves are utilized to perform a rapid and uniform pre-cooking treatment on the chickpeas.

[0032] Step (5), packaging and storage of finished products: drain the chickpeas pre-cooked by microwave, quickly perform vacuum sealing packaging, and store them at 25°C.

[0033] Example 2: A cowpea pretreated at a microwave power of 160 W is prepared according to the following steps: Step (1), material preparation and screening: screen and accurately weigh 60 g of cowpea to ensure that the raw materials are fresh.

[0034] Step (2), washing the grains: the cowpeas weighed in step (1) are thoroughly washed to remove impurities, dust and dirt attached to the surface to ensure the cleanliness of the cowpeas.

[0035] Step (3), soaking of grains: Soak the washed cowpeas in a constant temperature water bath at 40°C for 2 h at a material-water ratio of 1:3 (i.e. 1 part cowpeas to 3 parts water). This process is intended to allow the cowpeas to fully absorb water and soften their tissue structure in preparation for subsequent microwave pre-cooking.

[0036] Step (4), microwave pre-cooking treatment: Move the cowpeas after constant temperature soaking into a microwave device, set the microwave power to 160W, the microwave frequency to 30 s / time, and the number of microwaves to 6 times. Utilize the penetration and heating uniformity of microwaves to perform a rapid and uniform pre-cooking treatment on the cowpeas.

[0037] Step (5), packaging and storage of finished products: drain the microwave-pre-cooked cowpeas, quickly seal them in a vacuum package, and store them at 25°C. 60 g Example 3: A mung bean pretreated at a microwave power of 160 W is prepared according to the following steps: Step (1), material preparation and screening: screen and accurately weigh mung beans to ensure that the raw materials are fresh.

[0038] Step (2), washing the grains: the mung beans weighed in step (1) are washed thoroughly to remove impurities, dust and dirt attached to the surface to ensure the cleanliness of the mung beans.

[0039] Step (3), soaking of grains: the washed mung beans are placed in a constant temperature water bath at 40°C and soaked for 2 h at a material-water ratio of 1:3 (i.e. 1 part mung beans to 3 parts water). This process is intended to allow the mung beans to fully absorb water and soften their tissue structure in preparation for subsequent microwave pre-cooking.

[0040] Step (4), microwave pre-cooking treatment: transfer the mung beans after constant temperature soaking to a microwave device, set the microwave power to 160 W, the microwave frequency to 30 s / time, and the number of microwaves to 8 times. Utilize the penetration and heating uniformity of microwaves to perform a rapid and uniform pre-cooking treatment on the mung beans.

[0041] Step (5), packaging and storage of finished products: drain the water from the microwave pre-cooked mung beans, quickly perform vacuum sealing packaging, and store them at 25°C.

[0042] Example 4: A black bean pretreated at a microwave power of 160 W is prepared according to the following steps: Step (1), material preparation and screening: screen and accurately weigh 60 g of black beans to ensure that the raw materials are fresh.

[0043] Step (2), washing the grains: thoroughly washing the black beans weighed in step (1) to remove impurities, dust and dirt attached to the surface to ensure the cleanliness of the black beans.

[0044] Step (3), soaking of grains: Soak the washed black beans in a constant temperature water bath at 40°C for 2 h at a material-water ratio of 1:3 (i.e., 1 part black beans to 3 parts water). This process is intended to allow the black beans to fully absorb water and soften their tissue structure in preparation for subsequent microwave pre-cooking.

[0045] Step (4), microwave pre-cooking treatment: transfer the black beans after constant temperature soaking to a microwave device, set the microwave power to 160 W, the microwave frequency to 30 s / time, and the number of microwaves to 8 times. Utilize the penetration and heating uniformity of microwaves to perform a rapid and uniform pre-cooking treatment on the black beans.

[0046] Step (5), packaging and storage of finished products: drain the water from the microwave pre-cooked black beans, quickly perform vacuum sealing packaging, and store them at 25°C.

[0047] Example 5: Brown rice pretreated at 160 W microwave power is prepared according to the following steps: Step (1), material preparation and screening: screen and accurately weigh 60 g of brown rice to ensure that the raw materials are fresh.

[0048] Step (2), washing the grains: the brown rice weighed in step (1) is thoroughly washed to remove impurities, dust and dirt attached to the surface to ensure the cleanliness of the brown rice.

[0049] Step (3), soaking of grains: the washed brown rice is placed in a constant temperature water bath at 40°C and soaked for 2 h at a material-water ratio of 1:3 (i.e. 1 part brown rice, 3 parts water). This process is intended to allow the brown rice to fully absorb water and soften its tissue structure in preparation for subsequent microwave pre-cooking.

[0050] Step (4), microwave pre-cooking treatment: the brown rice after constant temperature soaking is transferred to the microwave equipment, and the microwave power is set to 160W, the microwave frequency is set to 30 s / time, and the number of microwaves is set to 6 times. The penetration and heating uniformity of microwaves are used to pre-cook the brown rice quickly and evenly.

[0051] Step (5), packaging and storage of finished products: drain the water from the microwave pre-cooked brown rice, quickly perform vacuum sealing packaging, and store it at 25°C.

[0052] Example 6: Chickpeas pretreated at 320 W microwave power were prepared according to the following steps: Step (1), material preparation and screening: screen and accurately weigh 60 g of chickpeas to ensure that the raw materials are fresh.

[0053] Step (2), washing the grains: the chickpeas weighed in step (1) are thoroughly washed to remove impurities, dust and dirt attached to the surface to ensure the cleanliness of the chickpeas.

[0054] Step (3), soaking of grains: the washed chickpeas are placed in a constant temperature water bath at 40°C and soaked for 2 h at a material-water ratio of 1:3 (i.e. 1 part chickpeas to 3 parts water). This process is intended to allow the chickpeas to fully absorb water and soften their tissue structure in preparation for subsequent microwave pre-cooking.

[0055] Step (4), microwave pre-cooking treatment: Move the chickpeas after constant temperature soaking into a microwave device, set the microwave power to 320 W, the microwave frequency to 30 s / time, and the number of microwaves to 7 times. Utilize the penetration and heating uniformity of microwaves to perform a rapid and uniform pre-cooking treatment on the chickpeas.

[0056] Step (5), packaging and storage of finished products: drain the chickpeas pre-cooked by microwave, quickly perform vacuum sealing packaging, and store them at 25°C.

[0057] Example 7: A cowpea pretreated at a microwave power of 320 W is prepared according to the following steps: Step (1), material preparation and screening: screen and accurately weigh 60 g of cowpea to ensure that the raw materials are fresh.

[0058] Step (2), washing the grains: the cowpeas weighed in step (1) are thoroughly washed to remove impurities, dust and dirt attached to the surface to ensure the cleanliness of the cowpeas.

[0059] Step (3), soaking of grains: Soak the washed cowpeas in a constant temperature water bath at 40°C for 2 h at a material-water ratio of 1:3 (i.e. 1 part cowpeas to 3 parts water). This process is intended to allow the cowpeas to fully absorb water and soften their tissue structure in preparation for subsequent microwave pre-cooking.

[0060] Step (4), microwave pre-cooking treatment: transfer the cowpeas soaked at a constant temperature into a microwave device, set the microwave power to 320 W, the microwave frequency to 30 s / time, and the number of microwaves to 6 times. Utilize the penetration and heating uniformity of microwaves to perform a rapid and uniform pre-cooking treatment on the cowpeas.

[0061] Step (5), packaging and storage of finished products: drain the microwave pre-cooked cowpeas, quickly seal them in a vacuum package, and store them at 25°C.

[0062] Example 8: A mung bean pretreated at a microwave power of 320 W is prepared according to the following steps: Step (1), material preparation and screening: screen and accurately weigh 60 g of mung beans to ensure that the raw materials are fresh.

[0063] Step (2), washing the grains: the mung beans weighed in step (1) are washed thoroughly to remove impurities, dust and dirt attached to the surface to ensure the cleanliness of the mung beans.

[0064] Step (3), soaking of grains: the washed mung beans are placed in a constant temperature water bath at 40°C and soaked for 2 h at a material-water ratio of 1:3 (i.e. 1 part mung beans to 3 parts water). This process is intended to allow the mung beans to fully absorb water and soften their tissue structure in preparation for subsequent microwave pre-cooking.

[0065] Step (4), microwave pre-cooking treatment: transfer the mung beans after constant temperature soaking to a microwave device, set the microwave power to 320 W, the microwave frequency to 30 s / time, and the number of microwaves to 8 times. Utilize the penetration and heating uniformity of microwaves to perform a rapid and uniform pre-cooking treatment on the mung beans.

[0066] Step (5), packaging and storage of finished products: drain the water from the microwave pre-cooked mung beans, quickly perform vacuum sealing packaging, and store them at 25°C.

[0067] Example 9: A black bean pretreated at a microwave power of 320 W is prepared according to the following steps: Step (1), material preparation and screening: screen and accurately weigh 60 g of black beans to ensure that the raw materials are fresh.

[0068] Step (2), washing the grains: thoroughly washing the black beans weighed in step (1) to remove impurities, dust and dirt attached to the surface to ensure the cleanliness of the black beans.

[0069] Step (3), soaking of grains: Soak the washed black beans in a constant temperature water bath at 40°C for 2 h at a material-water ratio of 1:3 (i.e., 1 part black beans to 3 parts water). This process is intended to allow the black beans to fully absorb water and soften their tissue structure in preparation for subsequent microwave pre-cooking.

[0070] Step (4), microwave pre-cooking treatment: transfer the black beans after constant temperature soaking to a microwave device, set the microwave power to 320 W, the microwave frequency to 30 s / time, and the number of microwaves to 8 times. The penetration and heating uniformity of microwaves are utilized to perform a rapid and uniform pre-cooking treatment on the black beans.

[0071] Step (5), packaging and storage of finished products: drain the water from the microwave pre-cooked black beans, quickly perform vacuum sealing packaging, and store them at 25°C.

[0072] Example 10: Brown rice pretreated at 320 W microwave power is prepared according to the following steps: Step (1), material preparation and screening: screen and accurately weigh 60 g of brown rice to ensure that the raw materials are fresh.

[0073] Step (2), washing the grains: the brown rice weighed in step (1) is thoroughly washed to remove impurities, dust and dirt attached to the surface to ensure the cleanliness of the brown rice.

[0074] Step (3), soaking of grains: the washed brown rice is placed in a constant temperature water bath at 40°C and soaked for 2 h at a material-water ratio of 1:3 (i.e. 1 part brown rice, 3 parts water). This process is intended to allow the brown rice to fully absorb water and soften its tissue structure in preparation for subsequent microwave pre-cooking.

[0075] Step (4), microwave pre-cooking treatment: the brown rice after constant temperature soaking is transferred to the microwave equipment, and the microwave power is set to 320 W, the microwave frequency is set to 30 s / time, and the number of microwaves is set to 6 times. The penetration and heating uniformity of microwaves are used to pre-cook the brown rice quickly and evenly.

[0076] Step (5), packaging and storage of finished products: drain the water from the microwave pre-cooked brown rice, quickly perform vacuum sealing packaging, and store it at 25°C.

[0077] Example 11: Chickpeas pretreated at 480 W microwave power were prepared according to the following steps: Step (1), material preparation and screening: screen and accurately weigh 60 g of chickpeas to ensure that the raw materials are fresh.

[0078] Step (2), washing the grains: the chickpeas weighed in step (1) are thoroughly washed to remove impurities, dust and dirt attached to the surface to ensure the cleanliness of the chickpeas.

[0079] Step (3), soaking of grains: the washed chickpeas are placed in a constant temperature water bath at 40°C and soaked for 2 h at a material-water ratio of 1:3 (i.e. 1 part chickpeas to 3 parts water). This process is intended to allow the chickpeas to fully absorb water and soften their tissue structure in preparation for subsequent microwave pre-cooking.

[0080] Step (4), microwave pre-cooking treatment: transfer the chickpeas after constant temperature soaking to a microwave device, set the microwave power to 480 W, the microwave frequency to 30 s / time, and the number of microwaves to 7 times. The penetrability and heating uniformity of microwaves are utilized to perform a rapid and uniform pre-cooking treatment on the chickpeas.

[0081] Step (5), packaging and storage of finished products: drain the chickpeas pre-cooked by microwave, quickly perform vacuum sealing packaging, and store them at 25°C.

[0082] Example 12: A cowpea pretreated at a microwave power of 480 W is prepared according to the following steps: Step (1), material preparation and screening: screen and accurately weigh 60 g of cowpea to ensure that the raw materials are fresh.

[0083] Step (2), washing the grains: the cowpeas weighed in step (1) are thoroughly washed to remove impurities, dust and dirt attached to the surface to ensure the cleanliness of the cowpeas.

[0084] Step (3), soaking of grains: Soak the washed cowpeas in a constant temperature water bath at 40°C for 2 h at a material-water ratio of 1:3 (i.e. 1 part cowpeas to 3 parts water). This process is intended to allow the cowpeas to fully absorb water and soften their tissue structure in preparation for subsequent microwave pre-cooking.

[0085] Step (4), microwave pre-cooking treatment: transfer the cowpeas soaked at a constant temperature into a microwave device, set the microwave power to 480 W, the microwave frequency to 30 s / time, and the number of microwaves to 6 times. Utilize the penetration and heating uniformity of microwaves to perform a rapid and uniform pre-cooking treatment on the cowpeas.

[0086] Step (5), packaging and storage of finished products: drain the microwave pre-cooked cowpeas, quickly seal them in a vacuum package, and store them at 25°C.

[0087] Example 13: A mung bean pretreated at a microwave power of 480 W is prepared according to the following steps: Step (1), material preparation and screening: screen and accurately weigh 60 g of mung beans to ensure that the raw materials are fresh.

[0088] Step (2), washing the grains: the mung beans weighed in step (1) are washed thoroughly to remove impurities, dust and dirt attached to the surface to ensure the cleanliness of the mung beans.

[0089] Step (3), soaking of grains: the washed mung beans are placed in a constant temperature water bath at 40°C and soaked for 2 h at a material-water ratio of 1:3 (i.e. 1 part mung beans to 3 parts water). This process is intended to allow the mung beans to fully absorb water and soften their tissue structure in preparation for subsequent microwave pre-cooking.

[0090] Step (4), microwave pre-cooking treatment: transfer the mung beans after constant temperature soaking to a microwave device, set the microwave power to 480 W, the microwave frequency to 30 s / time, and the number of microwaves to 8 times. The penetration and heating uniformity of microwaves are utilized to perform a rapid and uniform pre-cooking treatment on the mung beans.

[0091] Step (5), packaging and storage of finished products: drain the water from the microwave pre-cooked mung beans, quickly perform vacuum sealing packaging, and store them at 25°C.

[0092] Example 14: A black bean pretreated at a microwave power of 480 W is prepared according to the following steps: Step (1), material preparation and screening: screen and accurately weigh 60 g of black beans to ensure that the raw materials are fresh.

[0093] Step (2), washing the grains: thoroughly washing the black beans weighed in step (1) to remove impurities, dust and dirt attached to the surface to ensure the cleanliness of the black beans.

[0094] Step (3), soaking of grains: Soak the washed black beans in a constant temperature water bath at 40°C for 2 h at a material-water ratio of 1:3 (i.e., 1 part black beans to 3 parts water). This process is intended to allow the black beans to fully absorb water and soften their tissue structure in preparation for subsequent microwave pre-cooking.

[0095] Step (4), microwave pre-cooking treatment: transfer the black beans after constant temperature soaking to a microwave device, set the microwave power to 480 W, the microwave frequency to 30 s / time, and the number of microwaves to 8 times. The penetration and heating uniformity of microwaves are utilized to perform a rapid and uniform pre-cooking treatment on the black beans.

[0096] Step (5), packaging and storage of finished products: drain the water from the microwave pre-cooked black beans, quickly perform vacuum sealing packaging, and store them at 25°C.

[0097] Example 15: Brown rice pretreated at 480 W microwave power is prepared according to the following steps: Step (1), material preparation and screening: screen and accurately weigh 60 g of brown rice to ensure that the raw materials are fresh.

[0098] Step (2), washing the grains: the brown rice weighed in step (1) is thoroughly washed to remove impurities, dust and dirt attached to the surface to ensure the cleanliness of the brown rice.

[0099] Step (3), soaking of grains: the washed brown rice is placed in a constant temperature water bath at 40°C and soaked for 2 h at a material-water ratio of 1:3 (i.e. 1 part brown rice, 3 parts water). This process is intended to allow the brown rice to fully absorb water and soften its tissue structure in preparation for subsequent microwave pre-cooking.

[0100] Step (4), microwave pre-cooking treatment: the brown rice after constant temperature soaking is transferred to the microwave equipment, and the microwave power is set to 480 W, the microwave frequency is set to 30 s / time, and the number of microwaves is set to 6 times. The penetration and heating uniformity of microwaves are used to pre-cook the brown rice quickly and evenly.

[0101] Step (5), packaging and storage of finished products: drain the water from the microwave pre-cooked brown rice, quickly perform vacuum sealing packaging, and store it at 25°C.

[0102] Example 16: Chickpeas treated at a microwave power of 640 W were prepared according to the following steps: Step (1), material preparation and screening: screen and accurately weigh 60 g of chickpeas to ensure that the raw materials are fresh.

[0103] Step (2), washing the grains: the chickpeas weighed in step (1) are thoroughly washed to remove impurities, dust and dirt attached to the surface to ensure the cleanliness of the chickpeas.

[0104] Step (3), soaking of grains: the washed chickpeas are placed in a constant temperature water bath at 40°C and soaked for 2 h at a material-water ratio of 1:3 (i.e. 1 part chickpeas to 3 parts water). This process is intended to allow the chickpeas to fully absorb water and soften their tissue structure in preparation for subsequent microwave pre-cooking.

[0105] Step (4), microwave pre-cooking treatment: transfer the chickpeas after constant temperature soaking to a microwave device, set the microwave power to 640 W, the microwave frequency to 30 s / time, and the number of microwaves to 7 times. The penetrability and heating uniformity of microwaves are utilized to perform a rapid and uniform pre-cooking treatment on the chickpeas.

[0106] Step (5), packaging and storage of finished products: drain the chickpeas pre-cooked by microwave, quickly perform vacuum sealing packaging, and store them at 25°C.

[0107] Example 17: A cowpea treated at a microwave power of 640 W is prepared according to the following steps: Step (1), material preparation and screening: screen and accurately weigh 60 g of cowpea to ensure that the raw materials are fresh.

[0108] Step (2), washing the grains: the cowpeas weighed in step (1) are thoroughly washed to remove impurities, dust and dirt attached to the surface to ensure the cleanliness of the cowpeas.

[0109] Step (3), soaking of grains: Soak the washed cowpeas in a constant temperature water bath at 40°C for 2 h at a material-water ratio of 1:3 (i.e. 1 part cowpeas to 3 parts water). This process is intended to allow the cowpeas to fully absorb water and soften their tissue structure in preparation for subsequent microwave pre-cooking.

[0110] Step (4), microwave pre-cooking treatment: Move the cowpeas after constant temperature soaking into a microwave device, set the microwave power to 640 W, the microwave frequency to 30 s / time, and the number of microwaves to 6 times. Utilize the penetration and heating uniformity of microwaves to perform a rapid and uniform pre-cooking treatment on the cowpeas.

[0111] Step (5), packaging and storage of finished products: drain the microwave pre-cooked cowpeas, quickly seal them in a vacuum package, and store them at 25°C.

[0112] Example 18: A mung bean treated at a microwave power of 640 W is prepared according to the following steps: Step (1), material preparation and screening: screen and accurately weigh 60 g of mung beans to ensure that the raw materials are fresh.

[0113] Step (2), washing the grains: the mung beans weighed in step (1) are washed thoroughly to remove impurities, dust and dirt attached to the surface to ensure the cleanliness of the mung beans.

[0114] Step (3), soaking of grains: the washed mung beans are placed in a constant temperature water bath at 40°C and soaked for 2 h at a material-water ratio of 1:3 (i.e. 1 part mung beans to 3 parts water). This process is intended to allow the mung beans to fully absorb water and soften their tissue structure in preparation for subsequent microwave pre-cooking.

[0115] Step (4), microwave pre-cooking treatment: transfer the mung beans after constant temperature soaking to a microwave device, set the microwave power to 640 W, the microwave frequency to 30 s / time, and the number of microwaves to 8 times. Utilize the penetration and heating uniformity of microwaves to perform a rapid and uniform pre-cooking treatment on the mung beans.

[0116] Step (5), packaging and storage of finished products: drain the water from the microwave pre-cooked mung beans, quickly perform vacuum sealing packaging, and store them at 25°C.

[0117] Example 19: A black bean treated at a microwave power of 640 W is prepared according to the following steps: Step (1), material preparation and screening: screen and accurately weigh 60 g of black beans to ensure that the raw materials are fresh.

[0118] Step (2), washing the grains: thoroughly washing the black beans weighed in step (1) to remove impurities, dust and dirt attached to the surface to ensure the cleanliness of the black beans.

[0119] Step (3), soaking of grains: Soak the washed black beans in a constant temperature water bath at 40°C for 2 h at a material-water ratio of 1:3 (i.e., 1 part black beans to 3 parts water). This process is intended to allow the black beans to fully absorb water and soften their tissue structure in preparation for subsequent microwave pre-cooking.

[0120] Step (4), microwave pre-cooking treatment: transfer the black beans after constant temperature soaking to a microwave device, set the microwave power to 640 W, the microwave frequency to 30 s / time, and the number of microwaves to 8 times. The penetration and heating uniformity of microwaves are utilized to perform a rapid and uniform pre-cooking treatment on the black beans.

[0121] Step (5), packaging and storage of finished products: drain the water from the microwave pre-cooked black beans, quickly perform vacuum sealing packaging, and store them at 25°C.

[0122] Example 20: Brown rice treated at a microwave power of 640 W is prepared according to the following steps: Step (1), material preparation and screening: screen and accurately weigh 60 g of brown rice to ensure that the raw materials are fresh.

[0123] Step (2), washing the grains: the brown rice weighed in step (1) is thoroughly washed to remove impurities, dust and dirt attached to the surface to ensure the cleanliness of the brown rice.

[0124] Step (3), soaking of grains: the washed brown rice is placed in a constant temperature water bath at 40°C and soaked for 2 h at a material-water ratio of 1:3 (i.e. 1 part brown rice, 3 parts water). This process is intended to allow the brown rice to fully absorb water and soften its tissue structure in preparation for subsequent microwave pre-cooking.

[0125] Step (4), microwave pre-cooking treatment: the brown rice after constant temperature soaking is transferred to the microwave equipment, and the microwave power is set to 640 W, the microwave frequency is set to 30 s / time, and the number of microwaves is set to 6 times. The penetration and heating uniformity of microwaves are used to pre-cook the brown rice quickly and evenly.

[0126] Step (5), packaging and storage of finished products: drain the water from the microwave pre-cooked brown rice, quickly perform vacuum sealing packaging, and store it at 25°C.

[0127] Example 21: Chickpeas treated at 800 W microwave power were prepared according to the following steps: Step (1), material preparation and screening: screen and accurately weigh 60 g of chickpeas to ensure that the raw materials are fresh.

[0128] Step (2), washing the grains: the chickpeas weighed in step (1) are thoroughly washed to remove impurities, dust and dirt attached to the surface to ensure the cleanliness of the chickpeas.

[0129] Step (3), soaking of grains: the washed chickpeas are placed in a constant temperature water bath at 40°C and soaked for 2 h at a material-water ratio of 1:3 (i.e. 1 part chickpeas to 3 parts water). This process is intended to allow the chickpeas to fully absorb water and soften their tissue structure in preparation for subsequent microwave pre-cooking.

[0130] Step (4), microwave pre-cooking treatment: transfer the chickpeas after constant temperature soaking to a microwave device, set the microwave power to 800 W, the microwave frequency to 30 s / time, and the number of microwaves to 7 times. The penetrability and heating uniformity of microwaves are utilized to perform a rapid and uniform pre-cooking treatment on the chickpeas.

[0131] Step (5), packaging and storage of finished products: drain the chickpeas pre-cooked by microwave, quickly perform vacuum sealing packaging, and store them at 25°C.

[0132] Example 22: A cowpea treated at a microwave power of 800 W is prepared according to the following steps: Step (1), material preparation and screening: screen and accurately weigh 60 g of cowpea to ensure that the raw materials are fresh.

[0133] Step (2), washing the grains: the cowpeas weighed in step (1) are thoroughly washed to remove impurities, dust and dirt attached to the surface to ensure the cleanliness of the cowpeas.

[0134] Step (3), soaking of grains: Soak the washed cowpeas in a constant temperature water bath at 40°C for 2 h at a material-water ratio of 1:3 (i.e. 1 part cowpeas to 3 parts water). This process is intended to allow the cowpeas to fully absorb water and soften their tissue structure in preparation for subsequent microwave pre-cooking.

[0135] Step (4), microwave pre-cooking treatment: Move the cowpeas after constant temperature soaking into a microwave device, set the microwave power to 800 W, the microwave frequency to 30 s / time, and the number of microwaves to 6 times. Utilize the penetration and heating uniformity of microwaves to perform a rapid and uniform pre-cooking treatment on the cowpeas.

[0136] Step (5), packaging and storage of finished products: drain the microwave pre-cooked cowpeas, quickly seal them in a vacuum package, and store them at 25°C.

[0137] Example 23: A mung bean treated at a microwave power of 800 W is prepared according to the following steps: Step (1), material preparation and screening: screen and accurately weigh 60 g of mung beans to ensure that the raw materials are fresh.

[0138] Step (2), washing the grains: the mung beans weighed in step (1) are washed thoroughly to remove impurities, dust and dirt attached to the surface to ensure the cleanliness of the mung beans.

[0139] Step (3), soaking of grains: the washed mung beans are placed in a constant temperature water bath at 40°C and soaked for 2 h at a material-water ratio of 1:3 (i.e. 1 part mung beans to 3 parts water). This process is intended to allow the mung beans to fully absorb water and soften their tissue structure in preparation for subsequent microwave pre-cooking.

[0140] Step (4), microwave pre-cooking treatment: transfer the mung beans after constant temperature soaking to a microwave device, set the microwave power to 800 W, the microwave frequency to 30 s / time, and the number of microwaves to 8 times. The penetration and heating uniformity of microwaves are utilized to perform a rapid and uniform pre-cooking treatment on the mung beans.

[0141] Step (5), packaging and storage of finished products: drain the water from the microwave pre-cooked mung beans, quickly perform vacuum sealing packaging, and store them at 25°C.

[0142] Example 24: A black bean treated at a microwave power of 800 W is prepared according to the following steps: Step (1), material preparation and screening: screen and accurately weigh 60 g of black beans to ensure that the raw materials are fresh.

[0143] Step (2), washing the grains: thoroughly washing the black beans weighed in step (1) to remove impurities, dust and dirt attached to the surface to ensure the cleanliness of the black beans.

[0144] Step (3), soaking of grains: Soak the washed black beans in a constant temperature water bath at 40°C for 2 h at a material-water ratio of 1:3 (i.e., 1 part black beans to 3 parts water). This process is intended to allow the black beans to fully absorb water and soften their tissue structure in preparation for subsequent microwave pre-cooking.

[0145] Step (4), microwave pre-cooking treatment: transfer the black beans after constant temperature soaking to a microwave device, set the microwave power to 800 W, the microwave frequency to 30 s / time, and the number of microwaves to 8 times. The penetration and heating uniformity of microwaves are utilized to perform a rapid and uniform pre-cooking treatment on the black beans.

[0146] Step (5), packaging and storage of finished products: drain the water from the microwave pre-cooked black beans, quickly perform vacuum sealing packaging, and store them at 25°C.

[0147] Example 25: Brown rice treated at 800 W microwave power is prepared according to the following steps: Step (1), material preparation and screening: screen and accurately weigh 60 g of brown rice to ensure that the raw materials are fresh.

[0148] Step (2), washing the grains: the brown rice weighed in step (1) is thoroughly washed to remove impurities, dust and dirt attached to the surface to ensure the cleanliness of the brown rice.

[0149] Step (3), soaking of grains: the washed brown rice is placed in a constant temperature water bath at 40°C and soaked for 2 h at a material-water ratio of 1:3 (i.e. 1 part brown rice, 3 parts water). This process is intended to allow the brown rice to fully absorb water and soften its tissue structure in preparation for subsequent microwave pre-cooking.

[0150] Step (4), microwave pre-cooking treatment: the brown rice after constant temperature soaking is transferred to the microwave equipment, and the microwave power is set to 800 W, the microwave frequency is set to 30 s / time, and the number of microwaves is set to 6 times. The penetration and heating uniformity of microwaves are used to pre-cook the brown rice quickly and evenly.

[0151] Step (5), packaging and storage of finished products: drain the water from the microwave pre-cooked brown rice, quickly perform vacuum sealing packaging, and store it at 25°C.

[0152] Comparative Example 1: Chickpeas that have not been pretreated with microwaves are prepared according to the following steps: Step (1), material preparation and screening: screen and accurately weigh 60 g of chickpeas to ensure that the raw materials are fresh.

[0153] Step (2), washing the grains: the chickpeas weighed in step (1) are thoroughly washed to remove impurities, dust and dirt attached to the surface to ensure the cleanliness of the chickpeas.

[0154] Step (3), soaking grains: Soak the washed chickpeas in a constant temperature water bath at 40°C for 2 h at a material-water ratio of 1:3 (i.e. 1 part chickpeas to 3 parts water).

[0155] Step (4), packaging and storage of finished products: drain the chickpeas pre-cooked by microwaves, quickly perform vacuum sealing packaging, and store them at 25°C.

[0156] Comparative Example 2: A cowpea that has not been pretreated by microwave is prepared according to the following steps: Step (1), material preparation and screening: screen and accurately weigh 60 g of cowpea to ensure that the raw materials are fresh.

[0157] Step (2), washing the grains: the cowpeas weighed in step (1) are thoroughly washed to remove impurities, dust and dirt attached to the surface to ensure the cleanliness of the cowpeas.

[0158] Step (3), soaking grains: Soak the washed cowpeas in a constant temperature water bath at 40°C for 2 h at a material-water ratio of 1:3 (i.e. 1 part cowpeas to 3 parts water).

[0159] Step (4), packaging and storage of finished products: drain the microwave-pre-cooked cowpeas, quickly seal them in a vacuum package, and store them at 25°C. 60 g Comparative Example 3: Mung beans that have not been pretreated with microwaves are prepared according to the following steps: Step (1), material preparation and screening: screen and accurately weigh mung beans to ensure that the raw materials are fresh.

[0160] Step (2), washing the grains: the mung beans weighed in step (1) are washed thoroughly to remove impurities, dust and dirt attached to the surface to ensure the cleanliness of the mung beans.

[0161] Step (3), soaking grains: Soak the washed mung beans in a constant temperature water bath at 40°C for 2 h at a material-water ratio of 1:3 (i.e. 1 part mung beans to 3 parts water).

[0162] Step (4), packaging and storage of finished products: drain the water from the microwave pre-cooked mung beans, quickly perform vacuum sealing packaging, and store them at 25°C.

[0163] Comparative Example 4: Black beans without microwave pretreatment were prepared according to the following steps: Step (1), material preparation and screening: screen and accurately weigh 60 g of black beans to ensure that the raw materials are fresh.

[0164] Step (2), washing the grains: thoroughly washing the black beans weighed in step (1) to remove impurities, dust and dirt attached to the surface to ensure the cleanliness of the black beans.

[0165] Step (3), soaking grains: Soak the washed black beans in a constant temperature water bath at 40°C for 2 h at a material-water ratio of 1:3 (i.e. 1 part black beans to 3 parts water).

[0166] Step (4), packaging and storage of finished products: drain the water from the microwave pre-cooked black beans, quickly perform vacuum sealing packaging, and store them at 25°C.

[0167] Comparative Example 5: Brown rice without microwave pretreatment is prepared according to the following steps: Step (1), material preparation and screening: screen and accurately weigh 60 g of brown rice to ensure that the raw materials are fresh.

[0168] Step (2), washing the grains: the brown rice weighed in step (1) is thoroughly washed to remove impurities, dust and dirt attached to the surface to ensure the cleanliness of the brown rice.

[0169] Step (3), soaking grains: soak the washed brown rice in a constant temperature water bath at 40°C for 2 h at a material-water ratio of 1:3 (i.e. 1 part brown rice to 3 parts water).

[0170] Step (4), finished product packaging and storage: drain the brown rice after microwave pre-cooking, quickly perform vacuum sealing packaging, and store it at 25°C.

[0171] Performance tests were performed on the microwave pre-cooked cereals prepared in Examples 1 to 25 and the non-microwave pre-cooked cereals prepared in Comparative Examples 1 to 5: 1. Best cooking time test: The glass plate white core method was adopted, 250 mL of water was added to a 500 mL beaker, and the mixture was placed in a water bath on an induction cooker and heated to boiling. 60 g of Examples 1-25 and Comparative Examples 1-5 were weighed and poured into the beaker, and timing was started. After 15 min, at least 10 grains of cereals were taken out every 1 min, and the grains were squeezed using a glass plate to observe whether there was a white core. If there was no white core, the grains were cooked. The time when all the rice grains had no white core was recorded as the optimal cooking time.

[0172] like Figure 1As shown in the figure, the optimal cooking time of the pre-cooked grains is reduced. The optimal cooking times of chickpeas, cowpeas, mung beans, black beans, and brown rice in Examples 11-15 (microwave power of 480 W, microwave frequency of 30 s / time, and microwave times set to 7 times) are 29.67, 28.33, 30.33, 27.33, and 29.33 min, respectively. The reason why the optimal cooking time decreases with the increase of microwave power may be that the pre-cooking treatment changes the internal structure of the grains, causing starch gelatinization and protein denaturation. These changes make the grains easier to absorb water, swell, and soften during the cooking process, thereby reducing the time required to reach the optimal cooking state; the pre-cooking treatment makes it easier for the grains to achieve an ideal taste and texture during the cooking process, thereby reducing the cooking time.

[0173] 2. Gelatinization degree detection: Direct gelatinization test: Weigh 60 g of rice, chickpeas, cowpeas, black beans, mung beans and brown rice, and wash them three times with distilled water. Mix 60 g of grains with 120 mL of distilled water and add them to the rice cooker to steam for 30 min. Put the steamed grains into a 45 ℃ electric blast drying oven and dry them for 12 h. Take them out and crush them and pass them through a 60-mesh sieve for later use.

[0174] The degree of gelatinization was determined by the saccharification enzyme method. The specific operation is as follows: 1.00 g of the sample was weighed and placed in two 100 mL conical flasks, marked A and B respectively. 1 , A 2 , take another 100 mL Erlenmeyer flask without sample as blank, mark it B, and add 50 mL of distilled water to each of the three flasks. 1 Boil on a hotplate or in a boiling water bath for 20 min, then 1 The flask was quickly cooled to room temperature. 1 , A 2 Add 1 mL of 1% saccharifying enzyme solution (prepared before use) to each of the three conical flasks A, B, and shake in a 60 ℃ water bath for 1 h, then add 2 mL of 1 mol / L hydrochloric acid to the three conical flasks to inactivate the enzyme, and transfer to a 100 mL volumetric flask, dilute with distilled water, and use as the test solution after filtration. Take 10 mL of the test solution and place it in three 100 mL ground-mouth conical flasks with stoppers, add 10 mL of 0.05 mol / L iodine solution and 18 mL of 0.1 mol / L sodium hydroxide solution, respectively, then add stoppers and place in a dark place for 15 minutes. After standing, add 2 mL of 10% sulfuric acid to each of the above three conical flasks, and titrate with 0.1 mol / L sodium thiosulfate until the blue color becomes lighter, then add 1 mL of starch indicator, and continue to titrate until it is colorless and remains unchanged for 1 min. Record the number of milliliters of sodium thiosulfate consumed in each bottle, then: Where: V 0 The volume of sodium thiosulfate consumed in the titration blank, mL; V 1 Volume of sodium thiosulfate consumed to titrate the completely gelatinized sample, mL; V 2 The volume of sodium thiosulfate consumed to titrate the sample, mL.

[0175] like Figure 1 As shown in the figure, the gelatinization level of rice and different grains (chickpeas, brown rice, cowpeas, mung beans and black beans) after direct cooking without pretreatment is directly displayed. This key indicator reflects the degree of starch conversion and the degree of maturation of grains. The direct cooking gelatinization degree of rice is as high as 95.40%, while the direct cooking gelatinization degrees of chickpeas, brown rice, cowpeas, mung beans and black beans are 78.70%, 82.95%, 75.43%, 81.17% and 72.05% respectively, and rice is significantly higher than other grain varieties. According to national regulations, the direct cooking gelatinization degree of rice bran foods must be above 85%. Therefore, it can be seen that rice is easy to mature, while chickpeas, cowpeas, black beans, mung beans and brown rice are not easy to mature. Therefore, in order to improve the gelatinization degree of grains and the edible quality of grain rice, grains need to be pre-cooked.

[0176] Effect of microwave time and microwave power on gelatinization degree: Weigh 60g of chickpea, cowpea, black bean, mung bean and brown rice, and wash them with distilled water three times. Mix 60g of grains with 150mL of distilled water and soak them in a beaker in a constant temperature water bath at 40℃ for 2h. The soaked grains were placed in a microwave oven with a material-water ratio of 1:2.5, and different microwave powers (160W, 320W, 480W, 640W and 800W) were set. The microwave frequency was 30s / time, the time interval was 30s, and the number of microwaves was set to 7 times, 6 times, 8 times, 8 times and 6 times. The microwaved grains were placed in an electric rice cooker with a material-water ratio of 1:2.5 and cooked for 30 min. The cooked grains were placed in a 45℃ electric hot air drying oven and dried for 12h. After being taken out, they were crushed and passed through a 60-mesh sieve for later use.

[0177] The saccharifying enzyme method was used to determine the gelatinization degree of the samples, which was consistent with the direct cooking gelatinization degree determination method.

[0178] Figure 2 The experimental results shown reveal the effect of microwave processing parameters (i.e. microwave power) on the gelatinization degree (as an indicator of starch structural transformation) of five grains (chickpea, brown rice, black bean, mung bean and cowpea). Figure 2The trend analysis showed that with the increase of microwave power, the degree of gelatinization of the studied cereals gradually increased, indicating that microwave pretreatment effectively promoted the water absorption and expansion of starch granules and the destruction of the crystal structure, thereby accelerating the gelatinization process. Under 480 W microwave power treatment, the gelatinization degrees of chickpeas, brown rice, black beans, mung beans and cowpeas were measured to be 94.12%, 94.19%, 95.03%, 96.96% and 94.04%, respectively, which are quite close to the direct gelatinization degree of rice (95.40%). This finding emphasizes that the gelatinization characteristics of cereals can be significantly changed by optimizing microwave pretreatment conditions.

[0179] 3. Scanning electron microscope observation: The samples were subjected to a voltage of 5.0 kV and the morphological changes of the seed coat and cotyledons of the grains were observed by scanning electron microscopy. The sample particles were soaked in 3% (v / v) glutaraldehyde to physically harden the surface of the coating, then rinsed several times with 0.1M phosphate buffer, and then soaked in 1% osmium tetroxide at 4 °C. After five gradient elutions with ethanol, they were dried by critical point drying. The samples were coated by ion sputtering, observed by scanning electron microscopy, and photographed.

[0180] like Figure 4 As shown in the figure, this figure presents a direct comparison of the changes in the seed coat and cotyledon structure of five kinds of grains under different microwave treatment conditions. Cotyledon cells are the core energy storage tissue of seeds, and their interior is mainly composed of starch granules wrapped in a protein matrix. During the pre-ripening process, cotyledon cells will absorb a large amount of water, causing a significant volume expansion effect.

[0181] Compared with the control group (Comparative Examples 1-5), under the condition of 480 W (Examples 11-15), the starch of the five kinds of grains gelatinized and the protein structure denatured. This change caused the starch granules to be released from the original protein matrix. When the microwave power was increased to 800 W (Examples 21-25), the starch granules showed more serious deformation and even damage, while the protein network structure underwent excessive denaturation, which further accelerated the release process of the starch granules.

[0182] Microwave pre-cooking technology not only promotes the separation of cotyledons and seed coats, but also induces a gradual hydration process between the two. During this process, the water distribution inside the grains is reconstructed, resulting in overall expansion. Since the seed coat has a hard texture and relatively limited water absorption capacity, its expansion degree is far less than that of the cotyledons. Therefore, the significant expansion of the cotyledons becomes the main driving force for its separation from the seed coat. This process is intensified under the action of microwave pre-cooking, forming a larger spatial gap, which is conducive to the free penetration and distribution of subsequent water. Compared with comparative examples 1-5, under the condition of 480 W (Examples 11-15), it can be observed that the gap between the seed coat and the cotyledons is significantly increased. The seed coat of beans is generally divided into three parts: cuticle, palisade layer and hourglass cells; the structure of the seed coat determines the water transfer rate. When the microwave power is increased to 800 W (Examples 21-25), in addition to the further increase in the gap, the boundary between the pre-cooked seed coat palisade layer and the hourglass cells also becomes blurred.

[0183] 4. Changes in energy consumption: Use a power meter to accurately record the energy consumption of microwave pre-cooking of grains (soaking, microwaving, steaming).

[0184] The formula for energy consumption during the soaking process is: E(soaking) = P(heating) × t(heating) + P(maintenance) × t(maintenance); The formula for energy consumption during the microwave process is: E (microwave) = P (microwave power) × t (microwave time); The formula for energy consumption during the cooking process is: E(steaming) = P(average cooking power) × t(cooking time).

[0185] Total energy consumption calculation formula: E (total) = E (soaking) + E (microwave) + E (steaming) Table 1 Energy consumption of microwave pre-cooking of grains Direct cooking time Direct cooking energy consumption (KJ) Example 1-5 (J) Example 6-10 (J) Example 11-15 (J) Example 16-20 (J) Example 21-25 (J) Chickpeas 2 h <![CDATA[8.64×10 6 ]]> <![CDATA[2.28×10 5 ]]> <![CDATA[2.62×10 5 ]]> <![CDATA[2.95×10 5 ]]> <![CDATA[3.29×10 5 ]]> <![CDATA[3.62×10 5 ]]> cowpea 2 h <![CDATA[8.64×10 6 ]]> <![CDATA[2.23×10 5 ]]> <![CDATA[2.52×10 5 ]]> <![CDATA[2.81×10 5 ]]> <![CDATA[3.10×10 5 ]]> <![CDATA[3.38×10 5 ]]> green beans 1.5 h <![CDATA[6.48×10 6 ]]> <![CDATA[2.33×10 5 ]]> <![CDATA[2.71×10 5 ]]> <![CDATA[3.10×10 5 ]]> <![CDATA[3.48×10 5 ]]> <![CDATA[3.86×10 5 ]]> Black Beans 1 h <![CDATA[4.32×10 6 ]]> <![CDATA[2.33×10 5 ]]> <![CDATA[2.71×10 5 ]]> <![CDATA[3.10×10 5 ]]> <![CDATA[3.48×10 5 ]]> <![CDATA[3.86×10 5 ]]> brown rice 1 h <![CDATA[4.32×10 6 ]]> <![CDATA[2.23×10 5 ]]> <![CDATA[2.52×10 5 ]]> <![CDATA[2.81×10 5 ]]> <![CDATA[3.10×10 5 ]]> <![CDATA[3.38×10 5 ]]> It can be seen from Table 1 that the energy consumption of grains directly cooked without pre-cooking is higher, while the energy consumption of grains pre-cooked by microwaves is reduced during cooking. This shows that the internal structure and moisture state of grains pre-cooked by microwaves have changed, making the cooking process easier and more efficient. Specifically, microwave pre-cooking can make starch gelatinization and protein denaturation in grains occur in advance, so that the desired degree of cooking can be achieved faster during cooking. This not only shortens the cooking time, but also reduces the heat input required during the cooking process.

[0186] From the data in Table 1, we can see that compared with the grains that are directly cooked without pre-cooking, the energy consumption is relatively large. However, the energy consumption of the grains that have been pre-cooked by microwaves has been significantly reduced during the subsequent cooking process. This phenomenon fully demonstrates the significant effect of microwave pre-cooking on the internal structure and moisture state of grains, making the cooking process easier and more efficient. Microwave pre-cooking technology uses the characteristics of microwaves to quickly and evenly heat every part of the grains. This heating method not only causes the starch granules in the grains to gelatinize, that is, the structure between starch molecules changes, making it easier to absorb water, swell and soften; at the same time, it also promotes the denaturation of protein molecules, so that the structure of the protein is reorganized, making it easier to be digested and absorbed during the cooking process. These physical and chemical changes enable the grains to reach the required degree of maturity faster in the subsequent cooking process.

[0187] Since microwave pre-cooking has already completed some of the physical and chemical changes required for the cooking process, the cooking time can be greatly shortened in the subsequent cooking. At the same time, due to the changes in the internal structure of the grains, the heat input required in the cooking process is also reduced accordingly. In this way, not only the cooking efficiency is improved, but also the energy consumption is reduced, achieving the goal of energy saving and environmental protection.

[0188] In summary, microwave pre-cooking technology changes the internal structure and moisture state of grains, making the cooking process easier and more efficient. This technology not only improves the processing efficiency of grains, but also reduces energy consumption, which is of great significance for promoting the sustainable development of the grain processing industry.

[0189] Although the preferred embodiments of the present invention have been described, those skilled in the art may make other changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention.

[0190] Obviously, those skilled in the art can make various changes and modifications to the embodiments of the present invention without departing from the spirit and scope of the embodiments of the present invention. Thus, if these modifications and variations of the embodiments of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A processing method for improving the cooking properties of grains, characterized in that: The following steps are involved: Step 1: Raw material preparation and screening: remove solid impurities, foreign grains, imperfect grains and broken grains from the grains; Step 2: Raw material pretreatment: wash and drain the selected grains; Step 3: Constant temperature soaking: Soak the pre-treated grains in a constant temperature water bath; Step 4: using microwaves to perform differential pre-cooking treatment on the grains soaked at constant temperature: drying the grains soaked at constant temperature and transferring them to a microwave device, spreading the grains into a material layer with uniform thickness; calculating the weight per unit area of ​​the material layer according to the grain size and the weight of 100 grains of the grains, and determining the number of microwave heating times according to the weight per unit area of ​​the material layer; When the weight per unit area of ​​the material layer is 0.25-0.35 g / cm 2 When the microwave frequency is set to 6 times; When the weight per unit area of ​​the material layer is 0.35-0.45g / cm 2 When the microwave frequency is set to 7 times; When the weight per unit area of ​​the material layer is 0.45-0.55g / cm 2 When the microwave frequency is set to 8 times; Step 5: Packaging and storage of finished products: Drain the moisture from the microwave pre-cooked grains, quickly vacuum seal and pack them, and store them at room temperature.

2. A processing method for improving the cooking properties of grains according to claim 1, characterized in that: In step three, the constant temperature soaking process is: the pretreated grains are placed in a constant temperature water bath at 40° C. and soaked for 2 hours at a material-water ratio of 1:

3.

3. A processing method for improving the cooking properties of grains according to claim 1, characterized in that: In step 4, each microwave heating time is 30 seconds, and the time interval is 30 seconds.

4. A processing method for improving the cooking properties of grains according to claim 1, characterized in that: In step one, the selected grains are one of chickpeas, cowpeas, mung beans, black beans and brown rice, with a weight of 60 g; in step four, the material layer thickness is 10 mm, the number of microwave heating times of chickpeas, cowpeas, mung beans, black beans and brown rice is set to 7 times, 6 times, 8 times, 8 times and 6 times respectively, and the microwave heating power is set to 160 W ~ 800 W.

5. A processing method for improving the cooking properties of grains according to claim 4, characterized in that: In step 4, the microwave heating power is set to 480W.

6. A method for detecting the cooking characteristics of grains, characterized in that: Performing cooking characteristic testing on the grains processed by the method according to claim 1, wherein the cooking characteristic testing includes testing of optimal cooking time, testing of gelatinization degree, observation by scanning electron microscope and testing of energy consumption; The optimal cooking time test is to steam the cereals processed by the method according to claim 1, adopt the glass plate white core method, and record the time when all the cereals have no white core as the optimal cooking time; The gelatinization degree detection is to steam the grains processed by the method according to claim 1, and use the saccharifying enzyme method to detect the gelatinization degree of the steamed grains; The scanning electron microscope observation is to observe the grains processed by the method according to claim 1 using a scanning electron microscope to observe the morphological changes of the seed coat and cotyledons of the grains; The energy consumption test is to record the energy consumption of constant temperature soaking, microwave pre-cooking, and the energy consumption during the steaming of the grains when the grains are processed using the method as claimed in claim 1, and to obtain the total energy consumption required for complete cooking of the grains.

7. The method for detecting the cooking characteristics of grains according to claim 6, characterized in that: The optimal cooking time test comprises the following steps: 1) Add 250 mL of water into a 500 mL beaker and heat it to boiling in a water bath on an induction cooker; 2) Weigh 60 g of the grains processed by the method of claim 1 and pour them into a beaker, start timing, and after 15 minutes, take out at least 10 grains of grains every 1 minute, squeeze them with a glass plate, and observe whether the rice grains have a white core. If there is no white core, it means it is cooked; 3) The time when all rice grains have no white core is the optimal steaming time.

8. The method for detecting the cooking characteristics of grains according to claim 6, characterized in that: The method of using the saccharifying enzyme method to detect the degree of gelatinization of the cooked grains includes the following steps: 1) Take 60 g of the processed grains according to claim 1, mix with 120 mL of distilled water, add into the rice cooker and cook for 30 min; Put the cooked grains into a 45 ℃ electric blast drying oven and dry them for 12 h. Take them out and crush them and sieve them for later use. 2) Weigh 1.00 g of the sample obtained in step 1) and place it in two 100 mL Erlenmeyer flasks, label them A1 and A2 respectively. Take another 100 mL Erlenmeyer flask without adding the sample as a blank, label it B. Add 50 mL of distilled water to each of the three Erlenmeyer flasks. Boil A1 on an electric stove or heat it in a boiling water bath for 20 min, then cool the A1 flask to room temperature; 2) Add 1 mL of 1% saccharifying enzyme solution to each of the three conical flasks A1, A2, and B, shake them in a 60 ℃ water bath for 1 h, then add 2 mL of 1 mol / L hydrochloric acid to the three conical flasks to inactivate the enzyme, transfer to a 100 mL volumetric flask, make up to volume with distilled water, and filter it for use as the test solution; 3) Take 10 mL of the test solution and place them in three 100 mL ground-mouth Erlenmeyer flasks with stoppers. Add 10 mL of 0.05 mol / L iodine solution and 18 mL of 0.1 mol / L sodium hydroxide solution, respectively. Then stopper and place in a dark place for 15 min. After standing, add 2 mL of 10% sulfuric acid to each of the three Erlenmeyer flasks and titrate with 0.1 mol / L sodium thiosulfate until the blue color becomes lighter. Add 1 mL of starch indicator and continue to titrate until it becomes colorless and remains unchanged for 1 min. Record the number of milliliters of sodium thiosulfate consumed in each flask; obtain: Wherein, V0 is the volume of sodium thiosulfate consumed by titrating the blank, V1 is the volume of sodium thiosulfate consumed by titrating the completely gelatinized sample, and V2 is the volume of sodium thiosulfate consumed by titrating the sample.

9. The method for detecting the cooking characteristics of grains according to claim 6, characterized in that: The process of the scanning electron microscope observation is as follows: 1) Soak the sample particles in 3% glutaraldehyde to physically harden the surface of the coating; 2) Rinse the sample particles several times with 0.1 M phosphate buffer, then soak them in 1% osmium tetroxide at 4 °C, use ethanol gradient elution five times, and then dry them using the critical point drying method; 3) Coat the sample using ion sputtering, observe and photograph using a scanning electron microscope.

10. The method for detecting the cooking characteristics of grains according to claim 6, characterized in that: The energy consumption test includes the following process: 1) Use a power meter to record the energy E consumed by the grains during the constant temperature soaking process in the method of claim 1. 浸泡 : E 浸泡 = P 加热 × t 加热 + P 维持 × t 维持 ; Where P 加热 is the heating power of grains during soaking, t 加热 is the heating time; P 维持 The power required to maintain a constant temperature during the soaking process of grains, t 维持 Time to maintain constant temperature; 2) Use a power meter to record the energy E consumed by the grains during the microwave pre-cooking process in the method of claim 1. 微波 : E 微波 = P 微波 × t 微波 ; Among them, P 微波 is the microwave heating power, t 微波 Microwave heating time; 3) Use a power meter to record the energy E consumed in the cooking process of the grains processed by the method of claim 1. 蒸煮 : E 蒸煮 = P 蒸煮 × t 蒸煮 ; Where P 蒸煮 is the average power of the cooking process, t 蒸煮 is the cooking time; 4) Obtain the total energy consumption E required for the complete ripening of grains 总 =E 浸泡 +E 微波 +E 蒸煮 .

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