A processing method for semi-dry and easily-cooked whole grain rice or miscellaneous beans

Abstract

The present invention discloses a processing method for semi-dry and easily cooked whole grain rice or miscellaneous beans. The method comprises the following steps: spraying a preservative solution on the surface of the whole grain rice or miscellaneous bean raw material, stirring evenly and then standing for 15 min - 24 h to obtain a pretreated material; performing steam pressure difference puffing treatment on the pretreated material with steam containing alcohol; then, dispersing the sample, performing ultraviolet or ozone sterilization, drying to a certain moisture content, cooling, packaging, and thus obtaining the product. The method has a short processing cycle, can effectively inhibit the growth and reproduction of microorganisms, and can maintain the complete appearance of the product. The water content of the prepared whole grain rice or miscellaneous beans is between 20% - 28%, and they can be cooked together with rice until cooked through, with good taste, rich fragrance, and a long storage time.

Description

Technical Field

[0001] The present invention belongs to the field of whole grain food processing. In particular, it relates to a processing method for semi-dry and easy-to-cook whole grain rice or miscellaneous beans. Background Art

[0002] Whole grains refer to the grains with a complete structure retained after removing the inedible parts such as the outer shell of the grains, including three parts: endosperm, embryo, and seed coat. Whole grains are rich in dietary fiber, vitamins, mineral elements, and small molecule active substances such as plant polyphenols. As a unique "nutrient combination package", the synergistic effect of the "whole grain nutrient package" formed by the nutrients is more beneficial to human health than the simple addition of individual nutrients. In recent years, there have been more and more research reports on the health benefits of whole grains, including reducing the risks of heart disease, stroke, type 2 diabetes, colorectal cancer, and all-cause mortality, lower body mass index (BMI) and less obesity, reducing the risk of breast cancer, a healthier gut microbiota, reducing low-density lipoprotein, reducing inflammation, and delaying cognitive decline during the aging process. An analysis article based on the Global Burden of Disease Study 2017 in Lancet investigated the intake of major foods and nutrients in 195 countries around the world and quantitatively explored their impact on the incidence and mortality of chronic non-communicable diseases. The results showed that insufficient intake of whole grains is the leading dietary risk factor for chronic disease death and disability. The organizational structure of miscellaneous beans is the same as that of whole grains. A large number of studies have shown that miscellaneous beans also have nutritional effects similar to those of whole grains. However, at present, there is still a large gap between the intake of whole grains and miscellaneous beans and the recommended dietary intake for residents. This is mainly because the main components of the cortex of whole grains and miscellaneous beans are cellulose and hemicellulose, which have high strength and strong toughness. When eating whole grains, it is not easy for water to enter the interior of the grains, and they are not easy to gelatinize. The cooking time is long, and they cannot be cooked and cooked at the same time as rice. Generally, it requires long-term soaking, which is time-consuming and laborious. When cooked with white rice, the gelatinization is incomplete, the rice grains are hard, and the taste is poor, which cannot meet the consumers' requirements for food taste and convenience.

[0003] At present, there are also some pre-gelatinized brown rice products on the market that are dried after being pre-gelatinized by steaming, microwave, etc. However, after the starch inside the brown rice grains gelatinizes and then dries, the starch inside the grains recrystallizes, and the structure becomes more compact. When cooking again, it is still not easy for water to enter the interior of the grains. When cooked with rice, the gelatinization is incomplete, and the taste is hard. After being pre-gelatinized by steaming, microwave, etc. and then dried, the cracking rate of brown rice increases significantly, and the broken rice also increases accordingly, resulting in a decline in the quality of brown rice. If it is not dried after steaming, the water content in the cooked brown rice is relatively high, the water activity is large, and the microorganisms grow and reproduce rapidly during storage, making it not easy to store for a long time. More preservatives need to be added, and the nutrition and quality decline quickly. Other whole grain rice or miscellaneous beans also have similar problems to brown rice.

[0004] Therefore, it is necessary to find a new processing method to overcome the above-mentioned defects, that is, to maintain the easy-cooking characteristics of whole grain rice or miscellaneous beans, and at the same time enable the product to have a long shelf life, which is conducive to its circulation in the market. Summary of the Invention

[0005] The object of the present invention is to provide a processing method for semi-dry whole grain rice or miscellaneous beans. This method has a short processing cycle, can effectively inhibit the growth and reproduction of microorganisms, and can maintain the complete appearance of the product. The prepared whole grain rice or miscellaneous beans have a water content between 20% and 28%, can be cooked with rice at the same time and cooked thoroughly, have a good taste, a strong fragrance, and a long storage time.

[0006] To achieve the above object, the present invention adopts the following technical solutions:

[0007] In the first aspect, the present invention provides a processing method for semi-dry and easy-cooking whole grain rice or miscellaneous beans, which method comprises the following steps:

[0008] Spray a preservative solution on the surface of the whole grain rice or miscellaneous bean raw material, stir evenly and then stand for 15 min - 24 h to obtain a pretreated material;

[0009] Perform steam differential pressure puffing treatment on the pretreated material with steam containing alcohol at a temperature of 130°C - 230°C, a pressure of 0.2 MPa - 2.3 MPa, and hold the pressure for 15 s - 900 s. The volume concentration of alcohol in the steam containing alcohol is 0.1% - 2.5% (vol); preferably, the temperature of the steam differential pressure puffing treatment is 150°C - 190°C, the pressure is 0.4 MPa - 1.2 MPa, and the pressure holding time is 90 s - 300 s.

[0010] Disperse the sample after steam differential pressure puffing treatment and perform ultraviolet or ozone sterilization;

[0011] Then, dry to a moisture content of 20% - 28%;

[0012] Cool and package to obtain the product.

[0013] It should be noted that the whole grain rice or miscellaneous bean raw material described in the present invention refers to a complete caryopsis, and its basic composition includes starchy endosperm, germ and pericarp, and the relative proportion of each component is the same as that of the complete caryopsis.

[0014] Optionally, the whole grain rice includes one or more of brown rice, oats, highland barley, wheat, barley, buckwheat, sorghum, coix seed, quinoa and amaranth; the miscellaneous beans include one or more of black beans, mung beans, peas, broad beans, adzuki beans, lentils, cowpeas, kidney beans and chickpeas.

[0015] Furthermore, the brown rice raw materials include one or more of early indica brown rice, late indica brown rice, japonica brown rice, indica glutinous brown rice, japonica glutinous brown rice, red rice, black rice, and purple rice.

[0016] The present invention uses the alcohol steam pressure difference puffing technology, combined with a small amount of preservatives, and multiple technologies such as ultraviolet or ozone sterilization to effectively lock the moisture in the sample and control the bacterial content in the product packaging, and prepares semi-dry whole grain rice or miscellaneous beans (with a moisture content of 20-28%). Although the moisture content of this semi-dry whole grain rice or miscellaneous beans is higher than that of completely dried whole grain rice or miscellaneous beans, it is resistant to storage, easy to cook, has a good taste, a strong fragrance, and maintains a good appearance of the product.

[0017] Furthermore, in the above method, the water content of the pretreatment material is 20%-45%. Spraying an aqueous solution of preservatives on the surface of the whole grain rice or miscellaneous bean raw materials, stirring evenly and then standing for 15 min - 24 h can ensure that the moisture inside and outside the whole grain rice or miscellaneous beans reaches equilibrium. If the standing time is less than 15 min, the external moisture of the particles is significantly higher than the internal moisture. During steam pressure difference puffing, the outer pericarp of the whole grain or miscellaneous beans cracks, the outer layer of starch gelatinizes, causing adhesion between the particles, damaging the integrity of the grains, and reducing the acceptable appearance. The internal water content is low and the pre-gelatinization effect cannot be achieved. If the standing time is more than 24 h, the production cycle is too long, and under high moisture conditions, the raw materials are prone to germination and mildew, challenging food safety.

[0018] Furthermore, the preservative is one or more of citric acid, chitosan, nisin, sodium diacetate, and tea polyphenols; preferably, the dosage of the preservative is 0.1‰ - 2‰ of citric acid based on the mass of the whole grain rice or miscellaneous bean raw materials, 0.1‰ - 6‰ of chitosan based on the mass of the whole grain rice or miscellaneous bean raw materials, 0.1‰ - 0.25‰ of nisin based on the mass of the whole grain rice or miscellaneous bean raw materials, 0.1‰ - 0.8‰ of sodium diacetate based on the mass of the whole grain rice or miscellaneous bean raw materials, and 0.1% - 1.0% of tea polyphenols based on the mass of the whole grain rice or miscellaneous bean raw materials.

[0019] The present invention performs alcohol steam pressure difference puffing treatment on the pretreatment material, which places the whole grain rice or miscellaneous beans in a high-temperature and high-pressure environment. The raw materials after moisture adjustment are partially cooked by superheated alcohol steam. When the pressure is released instantaneously, the moisture inside the raw materials vaporizes instantaneously, and the volume expands instantaneously, causing the cell walls to rupture and forming moisture channels, which is conducive to the entry of moisture during cooking and reduces the cooking time; in addition, under the short-term treatment of high-temperature and high-pressure alcohol steam, the microorganisms on the surface of the whole grain rice or miscellaneous beans are killed, which is conducive to keeping the sample in a sterile state and is conducive to long-term storage; alcohol is volatile and will not cause residues, and will not have an adverse impact on the taste; alcohol performs steam pressure difference puffing treatment on the sample under high pressure, can penetrate into the cortex, sterilizes more thoroughly, uses less amount, has a better anti-corrosion effect, and is also conducive to reducing the usage amount of the previous preservatives.

[0020] Pressure is one of the key factors in the puffing treatment with the pressure difference of alcohol-water vapor. When the pressure is lower than 0.2, the pressure difference with air is small, and the sample cannot reach the pre-gelatinization degree. When the pressure is higher than 2.3, the surface of whole grain rice or miscellaneous beans is easily gelatinized, the epidermis cracks, and it is easy to adhere, affecting the dispersibility and integrity of the particles. The endosperm part of the sample is easily carbonized at a higher temperature, reducing the quality. The boiling point of the alcohol aqueous solution is lower than that of water, enabling the sample to reach a higher pressure at a lower temperature, which is beneficial for the sample to maintain a good appearance.

[0021] In addition, the volume concentration of alcohol in the water vapor containing alcohol is preferably controlled between 0.1% and 2.5%. A high alcohol concentration has good sterilization and temperature reduction effects, but there is also a risk of explosion. Therefore, the alcohol concentration should not exceed 2.5%.

[0022] Furthermore, the ozone concentration in the above method is not higher than 0.15 ppm.

[0023] Furthermore, the drying method includes microwave drying, freeze drying or hot air drying.

[0024] Furthermore, the packaging includes vacuum packaging, nitrogen filling packaging or carbon dioxide filling packaging.

[0025] Furthermore, the packaging uses high-barrier packaging materials.

[0026] In the second aspect, the present invention also claims to protect the semi-dry and easy-to-cook whole grain rice or miscellaneous beans prepared by the above processing method. The water content of the packaged semi-dry whole grain rice or miscellaneous beans is 20%-28%. By maintaining a relatively high water content, only a small amount of water needs to be absorbed during the cooking process to be cooked, reducing the water absorption time and improving the water absorption efficiency, which is beneficial for cooking and ripening together with white rice.

[0027] Advantages of the present invention:

[0028] The storage-resistant and easy-to-cook semi-dry whole grain rice or miscellaneous beans prepared by the present invention maintain the original color and luster of the original whole grain rice or miscellaneous beans, with strong gloss and complete grain shape. They can be mixed with rice in any proportion and cooked and ripened together, with a strong fragrance. It is measured that for the semi-dry brown rice product prepared by the present invention, using the ordinary rice steaming mode and testing with a texture analyzer, its hardness is significantly lower than that of the original brown rice, only 60% of the texture hardness of the original brown rice, and there is no significant difference from the texture hardness of rice. The cooking time is reduced by 16 minutes compared with the original brown rice. The semi-dry brown rice product prepared by the present invention can be stored for more than 15 days at 30°C, more than 12 weeks at 4°C, and can be kept for more than 180 days under freezing. Description of the drawings

[0029] Figure 1Comparison diagram of the appearance of semi-dry brown rice prepared by this method and other methods (the semi-dry brown rice prepared by this method is on the left, and the semi-dry brown rice prepared by steaming method is on the right).

[0030] Figure 2 Comparison diagram of the surface and cross-section of the semi-dry brown rice prepared by the present invention, the original brown rice, and the semi-dry brown rice prepared by steaming method.

[0031] Figure 3 Comparison diagram of the water absorption rates of semi-dry brown rice, rice, and brown rice.

[0032] Figure 4 Comparison diagram of the ripening rates of semi-dry brown rice, rice, and brown rice.

[0033] Figure 5 Comparison diagram of semi-dry brown rice and brown rice (brown rice is on the left, and semi-dry brown rice is on the right).

[0034] Figure 6 Graph of the change in pH value during storage.

[0035] Figure 7 Graph of the change in total acid during storage.

[0036] Figure 8 Graph of the change in the number of spores during storage.

[0037] Figure 9 Comparison diagram of semi-dry red adzuki beans and ordinary red adzuki beans.

[0038] Figure 10 External and internal cortex structure diagrams of semi-dry red adzuki beans.

[0039] Figure 11 Microscopic structure diagram (SEM) of the epidermis and endosperm cross-section of semi-dry red adzuki beans.

[0040] Figure 12 pH value of semi-dry red adzuki beans during storage in Example 2.

[0041] Figure 13 Total acid value of semi-dry red adzuki beans during storage in Example 2.

[0042] Figure 14 pH value of semi-dry brown rice during storage in Comparative Example 1.

[0043] Figure 15 Total acid value of semi-dry brown rice during storage in Comparative Example 1.

[0044] Figure 16 Appearance of semi-dry brown rice stored for 8 weeks in Comparative Example 1.

[0045] Figure 17 Appearance of semi-dry red adzuki beans in Comparative Example 2. Detailed implementation method

[0046] The present invention discloses a processing method for semi-dry and easily-cooked whole grain rice or miscellaneous beans. Those skilled in the art can draw on the content of this article and appropriately improve the process parameters to achieve it. It should be particularly noted that all similar substitutions and modifications are obvious to those skilled in the art, and they are all regarded as included in the present invention. The method and product of the present invention have been described through preferred embodiments, and those related can obviously make changes or appropriate alterations and combinations to the methods described herein without departing from the content, spirit, and scope of the present invention to implement and apply the technology of the present invention.

[0047] To further understand the present invention, the following will clearly and completely describe the technical solutions in the embodiments of the present invention in combination with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0048] Unless otherwise specified, the reagents involved in the embodiments of the present invention are all commercially available products and can be obtained through commercial channels.

[0049] Example 1

[0050] A processing method for easily-cooked semi-dry whole grain brown rice, using brown rice as the processing raw material, includes the following steps:

[0051] 1) Environmental disinfection: Use an ultraviolet lamp to disinfect the environment overnight.

[0052] 2) Cleaning: Remove impurities, perform color sorting, and perform grain sorting on 1 part by mass of the raw material to obtain brown rice raw materials with uniform color and grain shape.

[0053] 3) Washing: Wash the cleaned brown rice raw materials three times to remove surface dust.

[0054] 4) Raw material pretreatment: Pour the washed brown rice into a closed container, evenly spray the aqueous solution of nisin on the surface of the raw material, the dosage of nisin is 0.25‰ of the mass of the brown rice, stir evenly and then seal and stand for 6h to obtain brown rice with a water content of 31%.

[0055] 5) Alcohol steam pressure difference puffing treatment: Place the brown rice obtained in step 4) in a steam pressure difference puffing reactor, and perform steam pressure difference puffing treatment with saturated alcohol steam (alcohol concentration is 0.2%) at a temperature of 180°C and a pressure of 0.9 MPa, and the pressure holding time is 180 s.

[0056] 6) Dispersion, drying and cooling: The paddy rice processed in step 5) is broken up, sterilized with 0.05 ppm ozone, and cooled to room temperature, with the moisture content maintained at 24%.

[0057] 7) Packaging: Vacuum packaging is carried out using a high-barrier packaging material. Preferably, the degree of vacuum is 30 Pa. This is the semi-dry paddy rice.

[0058] The semi-dry paddy rice maintains the original color and luster of the paddy rice, has a complete grain shape, a cracking rate lower than 5%, and a better appearance than the pre-cooked and gelatinized paddy rice. See Figure 1 . By performing scanning electron microscopy on paddy rice, pre-gelatinized paddy rice prepared by steaming, and semi-dry paddy rice prepared by this method (see Figure 2 ), it is found that: The cross-section of paddy rice shows that the intercellular structure is tight (see Figure 2 a) in Figure 2 ), the structure of the surface cortex of paddy rice is dense (see Figure 2 d) in Figure 2 ), and there is no moisture passage; for the pre-gelatinized paddy rice prepared by traditional steaming, the cross-section structure is dense, the starch granules are gelatinized and lose their original shape, and there is no moisture passage (see Figure 2 b) in Figure 2 ), while for the cross-section of the semi-dry paddy rice processed by the method of the present invention, due to the retention of some moisture, the structure of the original cells is retained, and there are gaps between the cells (see Figure 2 c) in Figure 2 ), and some moisture passages are retained. The surface cortex has gaps due to the pressure-difference puffing and steaming breaking the dense structure of the paddy rice epidermis (see Figure 2 f) in

[0059] These gaps will become moisture passages during the steaming process, allowing water to quickly enter the interior of the paddy rice grains, causing the starch inside the grains to gelatinize and shortening the steaming time.

[0059] For the water absorption rate experiment of semi-dry paddy rice, accurately weigh 10.00 g of the semi-dry paddy rice, paddy rice, and rice samples (denoted as m 1 ) processed by the above method and put them into 50 mL centrifuge tubes. Add 30 mL of deionized water at 30 °C. After gently shaking to immerse the samples in the water, immediately place them in a 30 °C constant temperature water bath and start timing. After soaking for 1 h, 2 h, 3.5 h, 5 h, 6 h, and 7 h, take them out, dry the excess water on the surface with gauze and filter paper, place them on a clean petri dish, and weigh them on an analytical balance as m 2 , and calculate the water absorption rate according to formula (1).

[0060]

[0061] The results are shown in Figure 3 . It can be seen from Figure 3 that the water absorption rate of semi-dry paddy rice is higher than that of paddy rice, and the longer the soaking time, the greater the difference in the water absorption rate between semi-dry paddy rice and paddy rice.

[0062] Semi-dry brown rice cooking experiments were carried out using "GB / T 25226-2010 Evaluation of the gelatinization time of rice grains during the cooking process". The method was to put 10.0 g of the sample into boiling water for heating. Every 1 minute, 10 grains of rice were taken and placed on a glass slide, covered with another glass slide, and pressed with fingers on the glass bottle. The number of completely gelatinized rice grains was recorded. The time required for all 10 grains of rice to reach the gelatinized state twice in a row was the cooking time. The results are shown in Figure 4 , and it can be seen from Figure 4 that the cooking time of polished rice is 16 minutes, the cooking time of brown rice is 36 minutes, while the cooking time of semi-dry brown rice only needs 20 minutes, which is very close to the cooking time of polished rice. It can achieve the same cooking and ripening as polished rice.

[0063] Texture experiments on semi-dry brown rice were carried out. 1 part by mass of rice was added with 1.6 parts by mass of clear water and steamed for 40 minutes. After simmering for 20 minutes, the semi-dry brown rice and brown rice are shown in Figure 5 , and it can be seen from the figure that the semi-dry brown rice is completely gelatinized, the cortex is ruptured, and the endosperm is exposed from the cortex. While the brown rice still maintains its original granular shape. TPA measurements were carried out on the three kinds of cooked rice with a texture analyzer, and the results are shown in Table 1.

[0064] Table 1 Comparison table of texture hardness, elasticity and chewiness of semi-dry brown rice, polished rice and brown rice

[0065]

[0066] It can be seen from Table 1 that the texture hardness of semi-dry brown rice is significantly lower than that of brown rice, the chewiness is significantly lower than that of brown rice and white rice, the elasticity is significantly higher than that of brown rice, and there is no significant difference from white rice. Semi-dry brown rice has a strong fragrance, a soft and glutinous taste, and its sensory quality is better than that of brown rice.

[0067] Storage experiments on semi-dry brown rice were carried out. The packaged brown rice was placed in an artificial climate chamber at 30 °C and 65% and a refrigerator at 4 °C for storage experiments. Samples were taken every 2 weeks to measure the total acid and pH value of the samples, and the growth of microorganisms in the samples was measured by the spore counting method.

[0068] The determination methods of total acid and pH value refer to the method of GB 12456-2021 with slight modifications. Weigh 15 g of the sample (accurate to 0.01 g), place it in a 250 mL conical flask, add 135 mL of carbon dioxide-free distilled water at 80 °C, mix well, place it in a boiling water bath and boil for 30 min (shake 2 to 3 times to dissolve all the organic acids in the sample in the solution), take it out, cool it to room temperature, filter it through a 100-mesh sieve, and measure the pH value of the solution with a pH meter. Pipette 70 mL of the filtrate into a clean 150 mL Erlenmeyer flask, add 4 drops of phenolphthalein indicator solution (10 g / L), and titrate with 0.1 mol / L sodium hydroxide standard titration solution until it turns slightly pink and does not fade for 30 s. Record the volume of 0.1 mol / L sodium hydroxide standard titration solution consumed. At the same time, conduct a blank experiment. Calculate the total acid content according to the following formula.

[0069]

[0070] X—the total acid content in the sample, in grams per kilogram (g / kg) or grams per liter (g / L);

[0071] c—the concentration of the sodium hydroxide standard titration solution, in moles per liter (mol / L);

[0072] V1—the volume of the sodium hydroxide standard titration solution consumed when titrating the sample, in milliliters (mL);

[0073] V2—the volume of the sodium hydroxide standard titration solution consumed in the blank experiment, in milliliters (mL);

[0074] m—the mass of the sample, in grams (g):

[0075] The results of pH value and total acid are shown in Figure 6 、 Figure 7 . During storage at 4 °C for 12 weeks (84 days), there were no significant differences in the pH value, total acid, and total spore count of semi-dry brown rice compared with those of brown rice, indicating good storage performance. When stored at 30 °C, there was no significant difference in the total acid of semi-dry brown rice compared with that of ordinary brown rice.

[0076] For regular sampling, the spore counting method is used to determine the production of microorganisms in the sample. The spore counting method refers to "LS / T 6132-2018 Grain and Oil Inspection - Spore Counting Method for the Detection of Storage Fungi in Grain". Accurately weigh 10.0 g of the original sample into a stoppered test tube, add 30 mL of pure water, stopper it, shake it up and down for 1 min at a shaking frequency of 120 - 150 times per minute, filter it with a 300 - mesh filter cloth, and collect the filtrate in a stoppered test tube for standby. Cover a cover glass on the counting chamber of the counting plate. Shake the prepared filtrate well, immediately suck a little with a dropper, and drip a small drop (not too much) along the lower edge of the cover glass from the outermost side of the counting chamber, allowing the filtrate to siphon and fill the counting chamber at one time to prevent the generation of bubbles. After standing for 30 s, place the counting plate firmly on the stage of the microscope and observe and count under the high - power microscope. The spore counting results are shown in Table 2, and the situation under the microscope is shown in Figure 8 .

[0077] Table 2 Changes in the number of spores during storage

[0078]

[0079] It can be seen from Table 2 that there is no significant difference in the microbial growth between the semi - dry easy - cooking brown rice with a moisture content of 24% and the original brown rice with a moisture content of 12%; from Figure 8 it can be seen that there are many impurities in the original brown rice solution, while after the semi - dry brown rice is cleaned, treated by pressure - difference puffing and steaming, the surface is very clean, so the solution is also very clean.

[0080] Example 2

[0081] A processing method for easy - cooking semi - dry whole - grain adzuki beans, using adzuki beans as the processing raw material, including the following steps:

[0082] 1) Environmental disinfection: Use ozone to disinfect the environment and production water.

[0083] 2) Cleaning: Remove impurities, perform color sorting, and perform grain sorting on 1 part by mass of the raw material to obtain adzuki bean raw materials with uniform color and grain shape.

[0084] 3) Washing: Wash the cleaned adzuki bean raw materials once to remove surface dust.

[0085] 4) Raw material pretreatment: Pour the washed adzuki beans into a closed container, evenly spray the chitosan solution on the surface of the raw material, the dosage of chitosan is 0.6‰ of the mass of the adzuki beans, stir evenly and then close and stand for 12 h to obtain adzuki bean pretreatment materials with a moisture content of 36%.

[0086] 5) Alcohol-water vapor differential puffing treatment: Place the pre-treated adzuki bean material after water adjustment in a steam differential puffing reactor, and perform steam differential puffing treatment with saturated alcohol-water vapor (alcohol concentration is 0.7%) at a temperature of 200 °C and a pressure of 1.45 MPa. The pressure holding time is 240 s.

[0087] 6) Dispersion, drying and cooling: Break up the adzuki beans treated in step 5), then perform ultraviolet sterilization, and cool to room temperature, with the moisture content maintained at 28%.

[0088] 7) Packaging: Perform vacuum packaging using a high-barrier packaging material. Preferably, the vacuum degree is 35 Pa. This is the semi-dry and easy-to-cook adzuki beans.

[0089] The semi-dry and easy-to-cook adzuki beans maintain their original color, have strong gloss, complete grain shape, and low breakage rate, see Figure 9 。

[0090] Conduct the experiment of cooking at the same ripeness:

[0091] Semi-dry adzuki bean group: Put the above-prepared easy-to-cook adzuki beans and milled and peeled rice into the rice cooker at a ratio of 1:1;

[0092] Ordinary adzuki bean group: Put ordinary adzuki beans and milled and peeled rice into the rice cooker at a ratio of 1:1;

[0093] Control group: Put milled and peeled rice as a control into the rice cooker;

[0094] Steam 1 part by mass of the mixed rice with 1.6 parts by mass of clear water. Each group is steamed using the same method. The semi-dry adzuki beans have a strong fragrance, and there is no significant difference in texture hardness and viscosity between the semi-dry adzuki beans and the control group of rice, which is significantly lower than that of the ordinary adzuki bean group. The texture hardness is only 31% of that of the ordinary adzuki beans, achieving cooking at the same ripeness as rice. The elasticity of the semi-dry adzuki bean group is significantly higher than that of the ordinary adzuki bean group, and the chewiness is only 37% of that of the ordinary adzuki bean group, as shown in Table 3.

[0095] Table 3 Comparison of the texture of semi-dry adzuki beans, ordinary adzuki beans, and rice

[0096]

[0097] Use laser confocal microscopy to observe the epidermal structure of semi-dry easy-to-cook adzuki beans and ordinary adzuki beans, see Figure 10 。It can be seen from this that the external cortical structure of ordinary adzuki beans is complete, and the polygonal cell structure is clearly visible. The internal cortical structure is dense, and the fiber structure is complete. While for the semi-dry easy-to-cook adzuki beans, the waxy layer of the external cortex is damaged, the cell structure is damaged, the fibers of the internal cortex are damaged, the fiber structure becomes loose, and some fibers are broken. These structures are beneficial for water to enter during the cooking process.

[0098] The epidermal and endosperm cross-section structures of semi-dry easy-cooking adzuki beans and ordinary adzuki beans were observed using a scanning electron microscope, as shown in Figure 11 . It can be seen from this that the surface and endosperm cross-section structures of ordinary adzuki beans are dense. However, holes appear on the surface and endosperm cross-section of semi-dry easy-cooking adzuki beans, and cracks appear between cells in the endosperm. These structural changes create channels for water to enter the interior of the grains during the cooking process, enabling the interior of the grains to have sufficient water in a relatively short time to support the gelatinization of starch, shortening the gelatinization time, and improving the quality of semi-dry adzuki beans.

[0099] A storage experiment on semi-dry adzuki beans was carried out. The packaged adzuki beans were placed in an artificial climate chamber at 30 °C and 65% humidity and a refrigerator at 4 °C for the storage experiment. Samples were taken every two weeks to measure the total acid and pH value of the samples. The measurement method is shown in Example 1, and the measurement results are shown in Figure 12 and Figure 13 . During the storage process, as the storage time extended, the pH value decreased and the total acid value increased. After storing for 14 weeks (98 days) at 4 °C and 28 days at 30 °C, white mildew spots appeared on the semi-dry adzuki beans, and they were no longer suitable for storage.

[0100] Comparative Example 1

[0101] A processing method for easy-cooking semi-dry whole grain brown rice uses brown rice as the processing raw material and includes the following steps:

[0102] 1) Environmental disinfection: The environment is disinfected overnight using an ultraviolet lamp.

[0103] 2) Cleaning: 1 part by mass of the raw material is subjected to impurity removal, color sorting, and grain sorting to obtain brown rice raw materials with uniform color and grain shape.

[0104] 3) Washing: The cleaned brown rice raw materials are washed three times to remove surface dust.

[0105] 4) Raw material pretreatment: The washed brown rice is poured into a closed container, soaked in water for 6 h, then fished out and drained of water, stirred evenly, and then sealed and left standing for 6 h to obtain brown rice with a water content of 36%.

[0106] 5) Steam pressure difference puffing treatment: The water-adjusted brown rice is placed in a steam pressure difference puffing reactor and subjected to steam pressure difference puffing treatment using saturated steam at a temperature of 190 °C and a pressure of 1.15 MPa, and the pressure holding time is 150 s.

[0107] 6) Dispersion, drying, and cooling: The brown rice treated in step 5) is broken up, cooled to room temperature, and the water content is maintained at 30%.

[0108] 7) Packaging: Packaging is carried out using a high-barrier packaging material to obtain semi-dry brown rice.

[0109] The obtained semi-dry brown rice maintains the original color of brown rice, has strong gloss, complete grain shape, low percentage of cracked grains, and no significant difference in appearance from ordinary brown rice.

[0110] Conduct co-cooking experiment, cook it until cooked at the same time as rice, with strong fragrance and no significant difference in hardness from rice.

[0111] Storage experiment: Place the packaged semi-dry brown rice and the brown rice with the same packaging in a 4°C refrigerator for storage. Take out samples every two weeks to measure the pH value and total acid, and at the same time use the spore counting method to observe the change of microorganisms. The results of pH value, total acid and spore number are shown in Figure 14 、 Figure 15 , Table 4.

[0112] Table 4 Number of harmful fungal spores in semi-dry brown rice during storage

[0113]

[0114] As the storage time prolongs, the pH value of semi-dry brown rice drops rapidly, the total acid rises rapidly, and the spore number rises rapidly. At 28 days of storage, the number of harmful fungal spores is 5.1×10 6 , and the safety evaluation reaches the level of harm. At 42 days of storage, the number of harmful fungal spores is 2.5×10 7 , and the safety evaluation reaches the level of serious harm. At 56 days of storage, a large number of green bacterial plaques can be seen on the surface of semi-dry brown rice with the naked eye (see Figure 16 ).

[0115] Comparative Example 2

[0116] A processing method for semi-dry easy-cooking whole-grain adzuki beans, using adzuki beans as the processing raw material, including the following steps:

[0117] 1) Environmental disinfection: Use ozone to disinfect the environment overnight.

[0118] 2) Cleaning: Remove impurities, color selection, and grain selection from 1 part by mass of the raw material to obtain adzuki bean raw materials with uniform color and grain shape.

[0119] 3) Washing: Wash the cleaned adzuki bean raw materials once to remove surface dust.

[0120] 4) Raw material pretreatment: Pour the washed adzuki beans into a closed container, evenly spray the chitosan solution on the surface of the raw material, the dosage of chitosan is 0.6‰ of the mass of adzuki beans, stir evenly and then close and stand for 28h to obtain adzuki bean pretreatment materials with a water content of 42%.

[0121] 5) Steam pressure difference puffing treatment: the red bean pre-treated material after water adjustment is placed in a steam pressure difference puffing reactor, and steam pressure difference puffing treatment is carried out using saturated water vapor with a pressure of 2.4 MPa, and the pressure holding time is 360 seconds.

[0122] 6) Dispersion, drying and cooling: The pre-gelatinized adzuki beans are broken up, sterilized in 0.08 ppm ozone, cooled to room temperature, and the moisture content is maintained at 30%.

[0123] 7) Packaging: Use high barrier packaging materials for vacuum packaging, preferably, the vacuum degree is 30 Pa. This is semi-dried easy-to-cook red beans.

[0124] Under this pressure, the red bean skin cracks, exposing the endosperm inside, and sticks together, destroying the integrity of the red bean particles. Figure 17 In the experiment of cooking and cooking together, the red bean rice has a strong aroma, soft taste, and significantly lower hardness than ordinary red beans. After being stored at 4℃ for 3 weeks, a large number of green spots appeared on the surface, with an unpleasant odor.

[0125] The comparison between the embodiments and the comparative examples is shown in Table 5 below.

[0126] Table 5 Comparison of Examples and Comparative Examples

[0127]

[0128]

[0129] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not limitations on the implementation methods of the present invention. For ordinary technicians in the relevant field, other different forms of changes or modifications can be made based on the above description. It is impossible to list all the implementation methods here. All obvious changes or modifications derived from the technical solution of the present invention are still within the protection scope of the present invention.

Claims

1. A processing method for semi-dry and easy-to-cook whole grain rice or miscellaneous beans, characterized in that, the method comprises the following steps: Spray a preservative solution on the surface of the whole grain rice or miscellaneous bean raw material, stir evenly and let stand for 15 min - 24 h to obtain a pretreated material, and the water content of the pretreated material is 20% - 45%; the preservative is chitosan or nisin; the dosage of chitosan is 0.1‰ of the mass of the whole grain rice or miscellaneous bean raw material, and the dosage of nisin is 0.1‰ - 0.25‰ of the mass of the whole grain rice or miscellaneous bean raw material; Perform steam differential pressure puffing treatment on the pretreated material with steam containing alcohol at a temperature of 130°C - 230°C, a pressure of 0.2 MPa - 2.3 MPa, and hold the pressure for 15 s - 900 s, and the alcohol volume concentration in the steam containing alcohol is 0.1% - 2.5%; Disperse the sample after steam differential pressure puffing treatment and perform ultraviolet or ozone sterilization; Then, dry to a water content of 20% - 28%; Cool and package to obtain the product.

2. The processing method according to claim 1, characterized in that, the whole grain rice includes brown rice, oats, highland barley, wheat, barley, buckwheat, sorghum, coix seed, quinoa or amaranth; the miscellaneous beans include black beans, mung beans, peas, broad beans, adzuki beans, lentils, cowpeas, kidney beans or chickpeas.

3. The processing method according to claim 2, characterized in that, the brown rice includes early indica brown rice, late indica brown rice, japonica brown rice, indica glutinous brown rice, japonica glutinous brown rice, red rice, black rice or purple rice.

4. The processing method according to claim 1, characterized in that, the steam differential pressure puffing treatment temperature of the steam containing alcohol is 150°C - 190°C, the pressure is 0.4 MPa - 1.2 MPa, and the pressure holding time is 90 s - 300 s.

5. The processing method according to claim 1, characterized in that, the ozone concentration is not higher than 0.15 ppm.

6. The processing method according to claim 1, characterized in that, the drying method includes microwave drying, freeze drying or hot air drying.

7. The processing method according to claim 1, characterized in that, the packaging includes vacuum packaging, nitrogen filling packaging or carbon dioxide filling packaging.

8. The processing method according to claim 7, characterized in that, the packaging uses a high-barrier packaging material.

9. A semi-dry and easy-to-cook whole grain rice or miscellaneous beans prepared by the processing method according to any one of claims 1 - 8.

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