Preparation method of instant rice containing rice straw and corncob

Abstract

The invention relates to the technical field of food processing, in particular to a preparation method of rice straw and corncob instant rice. Comprising the following steps: rice straw treatment: crushing, removing impurities, adding a decomposition agent, adding urea to adjust the carbon nitrogen ratio, spraying water, and composting and fermenting at the temperature of 60-65 DEG C; corncob treatment: crushing, adding water to immerse corncobs, carrying out water pretreatment, heating and soaking, and removing impurities; mixing the treated rice straws, corncobs and rice according to a ratio, adding water to soak for 30-60 minutes, washing until the water is clear, adding water according to a rice-water ratio of 1: (1.2-1.8), steaming for 30-60 minutes, and braising for 10-20 minutes; and rehydration treatment: taking the cooked rice grains, putting the cooked rice grains in boiling water, covering the boiled water, and treating the cooked rice grains by a twin-screw extrusion method for 20-40 minutes. According to the invention, the rice straws and the corncobs are used as agricultural wastes, the wastes are turned into wealth through technical transformation, and the production cost is reduced.

Description

Technical Field

[0001] This invention relates to the field of food processing technology, and more specifically, to a method for preparing instant rice made from rice straw and corn cob. Background Technology

[0002] With the accelerating pace of life, the demand for convenient, quick, and nutritious foods is growing. Fast food has gained a significant market share because it can satisfy people's dietary needs in a short time. Fast food refers to pre-prepared foods that can be quickly provided to consumers; however, existing fast food products suffer from problems such as high salt, high oil, high calories, and nutritional imbalances.

[0003] Rice, as a staple food, is indispensable in people's diet. However, traditional rice cooking requires a certain amount of time and conditions, which is inconvenient for people living fast-paced lives.

[0004] Potatoes are one of the world's most important food crops, rich in nutrients such as carbohydrates, vitamins, minerals, and dietary fiber. However, potato products face technical challenges during processing, including difficulty in shaping, easy breakage, poor cooking resistance, and tendency to cloud the broth. Furthermore, processed potato products often have a poor taste.

[0005] Currently, the variety of instant rice products on the market is relatively limited, and there is still room for improvement in terms of taste, nutrition, and convenience. Furthermore, existing instant rice production processes suffer from problems such as complexity, high cost, and significant loss of nutritional components. Summary of the Invention

[0006] To solve the above-mentioned technical problems, the present invention provides a method for preparing instant rice made from rice straw and corn cob.

[0007] In a first aspect, the present invention provides a method for preparing instant rice made from rice straw and corn cob, comprising the following steps:

[0008] (1) Rice straw treatment: crush, remove impurities, add composting agent and urea to adjust carbon-nitrogen ratio, spray water, compost fermentation, temperature is 60-65℃;

[0009] (2) Corn cob processing: crush, add water to submerge the corn cob, pre-treat the water, heat and soak to remove impurities;

[0010] (3) Mix the treated rice straw, corn cob and rice in proportion, soak in water for 30-60 minutes, rinse until the water is clear, add water at a rice-to-water ratio of 1:1.2-1.8, steam for 30-60 minutes, and simmer for 10-20 minutes.

[0011] (4) Rehydration treatment: Take the rice grains after steaming and cooking, put them in boiling water and cover them, and process them by twin-screw extrusion method. The rehydration time is 20-40 minutes.

[0012] Preferably, in (1), the composting agent includes Trichoderma reesei, Trichoderma aureoviride, and Bacillus feederii, with a total bacterial count ≥ 200 million CFU / g.

[0013] Preferably, in (1), the mass ratio of the composting agent to the urea is 1-5:1-3.

[0014] Preferably, in (1), the moisture content of the rice straw is 60-70%.

[0015] Preferably, in step (2), the temperature of the heating and soaking is 120-135℃, and the soaking time is 120-160min.

[0016] Preferably, in step (3), the mass ratio of rice straw, corn cob and rice is 1-2:1-3:5-8.

[0017] Preferably, in step (3), the steaming temperature is 150-180°C.

[0018] Preferably, in step (4), the temperature of the twin-screw extrusion process is 120-150℃, the material moisture content is 30-40%, and the screw speed is 200-500 r / min.

[0019] In summary, the present invention has the following beneficial effects:

[0020] 1. The pretreated corn cobs in this invention have a high carbon-to-nitrogen ratio, which is much higher than that of ordinary corn cobs and rice straw. This characteristic enables them to act as high-quality electron donors during the rehydration process, promoting microbial metabolic activities, accelerating the release and conversion of nutrients, thereby improving the rehydration efficiency and taste of instant rice.

[0021] 2. In this invention, the rice straw contains capillary cavities and multi-level micro-nano structured walls, giving it excellent bottom-up water supply capabilities. This structure can efficiently transport water, and the channels are not easily blocked, providing a stable and uniform water supply basis for the rehydration of instant rice.

[0022] 3. This invention uses rice straw and corn cobs, which are agricultural waste, to achieve "turning waste into treasure" through technological transformation, thereby reducing production costs.

[0023] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and do not limit the scope of protection of the present invention. Detailed Implementation

[0024] The present invention will be further described in detail below with reference to the embodiments. It should be noted that: unless otherwise specified, the conditions in the following embodiments are carried out according to conventional conditions or the conditions recommended by the manufacturer. Unless otherwise specified, the raw materials used in the following embodiments can be obtained from commercially available sources.

[0025] The inventors of this invention have discovered existing types of instant rice, including ready-to-eat rice (open-bag), instant rice (such as Sengoku), canned rice (such as Merlin), frozen rice (refrigerated / aseptic / frozen), and self-heating rice. JD.com displays products covering self-heating rice, instant rice, and dry-mixed rice, from brands such as Haidilao and Zihaiguo, suitable for dormitories, offices, and other settings. To extend shelf life and improve taste, instant rice typically contains various food additives, such as preservatives and thickeners. While these additives are safe when used within regulated limits, long-term, high-dose intake may have adverse effects on human health. Furthermore, instant rice has a relatively simple nutritional composition, lacking the vitamins and minerals found in fresh vegetables and fruits; long-term consumption can easily lead to nutritional imbalances and negatively impact health.

[0026] Currently, the variety of instant rice products on the market is relatively limited, and there is still room for improvement in terms of taste, nutrition, and convenience. Furthermore, existing instant rice production processes suffer from problems such as complexity, high cost, and significant loss of nutritional components.

[0027] This invention provides a method for preparing instant rice made from rice straw and corn cob, comprising the following steps:

[0028] (1) Rice straw treatment: crush, remove impurities, add composting agent and urea to adjust carbon-nitrogen ratio, spray water, compost fermentation, temperature is 60-65℃;

[0029] (2) Corn cob processing: crush, add water to submerge the corn cob, pre-treat the water, heat and soak to remove impurities;

[0030] (3) Mix the treated rice straw, corn cob and rice in proportion, soak in water for 30-60 minutes, rinse until the water is clear, add water at a rice-to-water ratio of 1:1.2-1.8, steam for 30-60 minutes, and simmer for 10-20 minutes.

[0031] (4) Rehydration treatment: Take the rice grains after steaming and cooking, put them in boiling water and cover them, and process them by twin-screw extrusion method. The rehydration time is 20-40 minutes.

[0032] Optimizing the carbon-nitrogen ratio in raw material processing improves fermentation efficiency. In step (1) of rice straw processing, adding urea to adjust the carbon-nitrogen ratio, combined with composting with a ripening agent, can significantly accelerate the decomposition of organic matter. Adjusting the carbon-nitrogen ratio can improve the compost maturity. The carbon-nitrogen ratio can be precisely controlled by using professional equipment to accurately detect the maturity, ensuring sufficient fermentation and providing stable raw materials for subsequent mixing and cooking.

[0033] Extrusion puffing technology improves the rehydrated structure. In step (4), the rehydration treatment uses a twin-screw extrusion method, and it is pointed out that the twin-screw extruder has self-cleaning properties, strong conveying capacity, and puffing effect, which can form a porous structure. Comparison confirms that the instant rice prepared by the extrusion process has a higher rehydration rate (due to its low apparent density and loose structure), and its eating quality is close to that of fresh rice. The screw speed and temperature control during the extrusion process can optimize the product's puffing degree and crispness, which is consistent with the screw extrusion and boiling water treatment parameters in this technical specification.

[0034] Improving gelatinization accelerates rehydration. The key to rehydration performance lies in increasing the gelatinization degree of rice grains. Extrusion puffing allows starch to fully gelatinize, forming a porous structure that accelerates water penetration. This technology significantly improves gelatinization degree through dual processing of steaming (step 3) and extrusion (step 4): it shows that the gelatinization degree of extruded instant rice is higher than that of traditional processes, and also indicates a positive correlation between the moisture content of the extrusion feed and the α-gelatinization degree (gelatinization index).

[0035] Resource recycling and cost advantages: Using rice straw and corn cobs (agricultural waste) as raw materials (steps 1-2), the low-cost characteristics of urea in agriculture, combined with the high efficiency of urea as a nitrogen source, can reduce production costs. Simultaneously, the feasibility of using urea to regulate the carbon-nitrogen ratio in straw composting is confirmed, realizing the resource utilization of waste.

[0036] Based on the direction of screw rotation, twin-screw compressors can be divided into two categories: co-rotating and counter-rotating. Counter-rotating compressors can be further divided into inward and outward types. Co-rotating twin-screw compressors have different pressure zones. The material inside the sleeve cavity is affected by the rotation of the screw, creating a high-pressure zone and a low-pressure zone.

[0037] The material will flow from the high-pressure zone to the low-pressure zone in two directions: one is as the screw rotates, the wear of the square screw decreases, and the material is conveyed, sheared, mixed and heated by the outer shell of the barrel, and matured under high temperature and high pressure, and finally squeezed out of the barrel.

[0038] Reverse-rotating twin-screw extruders typically use two screws of identical dimensions but with opposite thread directions. The difference between inward and outward rotation lies in the location of the pressure zones. Inward rotation generates pressure that is higher at the top and lower at the bottom, resulting in extremely high pressure at the inlet and making feeding difficult; this type of inward reverse rotation is rarely used. Outward rotation generates pressure that is lower at the top and higher at the bottom, which is more conducive to feeding. However, compared to co-rotating, reverse rotation prevents the C-shaped material flow formed within the screws from moving from one screw to the other, significantly reducing the degree of mixing and making its self-cleaning ability less effective and stable than co-rotating twin-screw extruders.

[0039] In step (1), the composting agent includes Trichoderma reesei, Trichoderma aureoviride, and Bacillus feederii, with an effective viable count of ≥200 million CFU / g.

[0040] Trichoderma reesei is a common component of composting agents, especially in the treatment of organic waste (such as straw and manure). It can produce various decomposing enzymes (such as cellulase) to accelerate the composting process. It can produce decomposing enzymes to degrade straw, improving compost quality and crop growth indicators.

[0041] Trichoderma chloroticum is an antagonistic fungus that inhibits pathogens and promotes the decomposition of organic matter through hyperparasitism. It is commonly used in composting and soil improvement. As an exogenous decomposing microorganism, it is used to construct compound microbial agents.

[0042] *Paenibacillus pabuli* is a bacterium that efficiently degrades organic matter such as cellulose and is commonly used in feed fermentation and composting processes. It is used as a composting agent. The application of *Paenibacillus* sp. in cellulose-degrading complex microbial systems improves straw degradation rates, which is similar to the function of *Paenibacillus pabuli*, but no species name is specified. This more directly matches the question's mention of "*Paenibacillus pabuli*".

[0043] The pretreated corn cobs used in this invention have a high carbon-to-nitrogen ratio, far exceeding that of ordinary corn cobs and rice straw. This characteristic allows them to act as high-quality electron donors during rehydration, promoting microbial metabolic activity, accelerating the release and conversion of nutrients, and thus improving the rehydration efficiency and taste of instant rice.

[0044] In this invention, the rice straw contains capillary cavities and multi-level micro-nano structured walls, giving it excellent bottom-up water supply capabilities. This structure can efficiently transport water, and the channels are not easily blocked, providing a stable and uniform water supply basis for the rehydration of instant rice.

[0045] Soluble dietary fiber (SDF) can be extracted from corn cobs, which has physiological functions such as lowering blood sugar, lowering cholesterol, and enhancing immunity. If applied to instant rice, it can enhance the product's health value and meet modern consumers' demand for functional foods. Corn cob dietary fiber is more effective than insoluble fiber (IDF) and can help prevent cardiovascular disease and constipation.

[0046] The nutritional interaction between rice straw and corn cobs in instant rice: corn cobs, when cultivated, can produce a product with higher nutritional value (crude protein content up to 45%). Corn cobs, as a raw material or additive, enhance the protein or fiber content of instant rice. Furthermore, instant rice emphasizes the development of new "dietary fiber" products, suggesting health benefits.

[0047] Rice straw has a low sugar content, limiting its advantages as animal feed, but it has higher value in comprehensive utilization. Corn cobs release carbon stably when used in wastewater, but require pretreatment. The core advantages of rice straw and corn cobs in the fast-food rice industry chain lie in environmental protection, economy, and production efficiency; these materials can enhance the industry's competitiveness.

[0048] Adding a composting agent (containing cellulase and other microorganisms) can rapidly decompose organic matter such as cellulose and hemicellulose in straw, while urea provides a nitrogen source to regulate the carbon-nitrogen ratio (C / N), making microbial activity more efficient. This method can shorten the composting cycle to 20-25 days (compared to several months for traditional methods) and significantly improve the quality of composting.

[0049] Example

[0050] Example 1

[0051] A method for preparing instant rice made from rice straw and corn cob includes the following steps:

[0052] (1) Rice straw treatment: crush to 2-3cm, remove impurities, add composting agent and urea to adjust carbon-nitrogen ratio, spray water, compost fermentation, temperature is 60℃; carbon-nitrogen ratio is COD / TN=175.8.

[0053] (2) Corn cob processing: crush, add water to submerge the corn cob, pre-treat the water, heat and soak to remove impurities;

[0054] (3) Mix the treated rice straw, corn cob and rice in proportion, soak in water for 30-60 minutes, rinse until the water is clear, add water at a rice-to-water ratio of 1:1.2, steam for 30 minutes, and simmer for 10 minutes.

[0055] (4) Rehydration treatment: Take the rice grains after steaming and cooking, place them in boiling water and cover them, and process them by twin-screw extrusion method for 20 minutes.

[0056] In step (1), the composting agent includes Trichoderma reesei, Trichoderma aureoviride, and Bacillus feederii, with an effective viable count of ≥200 million CFU / g.

[0057] In step (1), the mass ratio of composting agent to urea is 1:1.

[0058] In step (1), the moisture content of the rice straw is 60%.

[0059] In step (2), the temperature for heating and soaking is 120℃ and the soaking time is 120min.

[0060] In step (3), the mass ratio of rice straw, corn cob and rice is 1:1:5.

[0061] In step (3), the steaming temperature is 150℃.

[0062] In step (4), the temperature of the twin-screw extrusion process is 120℃, the material moisture content is 30%, and the screw speed is 200 r / min.

[0063] Example 2

[0064] A method for preparing instant rice made from rice straw and corn cob includes the following steps:

[0065] (1) Rice straw treatment: crush to 2-3cm, remove impurities, add composting agent and urea to adjust carbon-nitrogen ratio, spray water, compost fermentation, temperature is 60℃; carbon-nitrogen ratio is COD / TN=175.8.

[0066] (2) Corn cob processing: crush, add water to submerge the corn cob, pre-treat the water, heat and soak to remove impurities;

[0067] (3) Mix the treated rice straw, corn cob and rice in proportion, soak in water for 30 minutes, rinse until the water is clear, add water at a rice-to-water ratio of 1:1.2, steam for 30 minutes, and simmer for 10 minutes.

[0068] (4) Rehydration treatment: Take the rice grains after steaming and cooking, place them in boiling water and cover them, and process them by twin-screw extrusion method for 20 minutes.

[0069] In step (1), the composting agent includes Trichoderma reesei, Trichoderma aureoviride, and Bacillus feederii, with an effective viable count of ≥200 million CFU / g.

[0070] In step (1), the mass ratio of composting agent to urea is 1:2.

[0071] In step (1), the moisture content of the rice straw is 60%.

[0072] In step (2), the temperature for heating and soaking is 120℃ and the soaking time is 120min.

[0073] In step (3), the mass ratio of rice straw, corn cob and rice is 1:1:5.

[0074] In step (3), the steaming temperature is 150℃.

[0075] In step (4), the temperature of the twin-screw extrusion process is 120℃, the material moisture content is 30%, and the screw speed is 200 r / min.

[0076] Example 3

[0077] A method for preparing instant rice made from rice straw and corn cob includes the following steps:

[0078] (1) Rice straw treatment: crush to 2-3cm, remove impurities, add composting agent and urea to adjust carbon-nitrogen ratio, spray water, compost fermentation, temperature is 61℃; carbon-nitrogen ratio is COD / TN=175.8.

[0079] (2) Corn cob processing: crush, add water to submerge the corn cob, pre-treat the water, heat and soak to remove impurities;

[0080] (3) Mix the treated rice straw, corn cob and rice in proportion, soak in water for 30-60 minutes, rinse until the water is clear, add water at a rice-to-water ratio of 1:1.2, steam for 30 minutes, and simmer for 10 minutes.

[0081] (4) Rehydration treatment: Take the rice grains after steaming and cooking, place them in boiling water and cover them, and process them by twin-screw extrusion method for 20 minutes.

[0082] In step (1), the composting agent includes Trichoderma reesei, Trichoderma aureoviride, and Bacillus feederii, with an effective viable count of ≥200 million CFU / g.

[0083] In step (1), the mass ratio of composting agent to urea is 1:1.

[0084] In step (1), the moisture content of the rice straw is 60%.

[0085] In step (2), the temperature for heating and soaking is 120℃ and the soaking time is 120min.

[0086] In step (3), the mass ratio of rice straw, corn cob and rice is 1:1:5.

[0087] In step (3), the steaming temperature is 150℃.

[0088] In step (4), the temperature of the twin-screw extrusion process is 120℃, the material moisture content is 30%, and the screw speed is 200 r / min.

[0089] Example 4

[0090] A method for preparing instant rice made from rice straw and corn cob includes the following steps:

[0091] (1) Rice straw treatment: crush to 2-3cm, remove impurities, add composting agent and urea to adjust carbon-nitrogen ratio, spray water, compost fermentation, temperature is 62℃; carbon-nitrogen ratio is COD / TN=175.8.

[0092] (2) Corn cob processing: crush, add water to submerge the corn cob, pre-treat the water, heat and soak to remove impurities;

[0093] (3) Mix the treated rice straw, corn cob and rice in proportion, soak in water for 30 minutes, rinse until the water is clear, add water at a rice-to-water ratio of 1:1.2, steam for 30 minutes, and simmer for 10 minutes.

[0094] (4) Rehydration treatment: Take the rice grains after steaming and cooking, place them in boiling water and cover them, and process them by twin-screw extrusion method for 20 minutes.

[0095] In step (1), the composting agent includes Trichoderma reesei, Trichoderma aureoviride, and Bacillus feederii, with an effective viable count of ≥200 million CFU / g.

[0096] In step (1), the mass ratio of composting agent to urea is 2:1.

[0097] In step (1), the moisture content of the rice straw is 60%.

[0098] In step (2), the temperature of the heating and soaking is 120-135℃ and the soaking time is 120-160min.

[0099] In step (3), the mass ratio of rice straw, corn cob and rice is 1:1:5.

[0100] In step (3), the steaming temperature is 150℃.

[0101] In step (4), the temperature of the twin-screw extrusion process is 120℃, the material moisture content is 30%, and the screw speed is 200r / min.

[0102] Example 5

[0103] A method for preparing instant rice made from rice straw and corn cob includes the following steps:

[0104] (1) Rice straw treatment: crush to 2-3cm, remove impurities, add composting agent and urea to adjust carbon-nitrogen ratio, spray water, compost fermentation, temperature is 61℃; carbon-nitrogen ratio is COD / TN=176.2.

[0105] (2) Corn cob processing: crush, add water to submerge the corn cob, pre-treat the water, heat and soak to remove impurities;

[0106] (3) Mix the treated rice straw, corn cob and rice in proportion, soak in water for 30-60 minutes, rinse until the water is clear, add water at a rice-to-water ratio of 1:1.2, steam for 30 minutes, and simmer for 10 minutes.

[0107] (4) Rehydration treatment: Take the rice grains after steaming and cooking, place them in boiling water and cover them, and process them by twin-screw extrusion method for 20 minutes.

[0108] In step (1), the composting agent includes Trichoderma reesei, Trichoderma aureoviride, and Bacillus feederii, with an effective viable count of ≥200 million CFU / g.

[0109] In step (1), the mass ratio of composting agent to urea is 1:1.

[0110] In step (1), the moisture content of the rice straw is 60%.

[0111] In step (2), the temperature for heating and soaking is 120℃ and the soaking time is 120min.

[0112] In step (3), the mass ratio of rice straw, corn cob and rice is 1:1:5.

[0113] In step (3), the steaming temperature is 150℃.

[0114] In step (4), the temperature of the twin-screw extrusion process is 120℃, the material moisture content is 30%, and the screw speed is 200 r / min.

[0115] Example 6

[0116] A method for preparing instant rice made from rice straw and corn cob includes the following steps:

[0117] (1) Rice straw treatment: crush to 2-3cm, remove impurities, add composting agent and urea to adjust carbon-nitrogen ratio, spray water, compost fermentation, temperature is 63℃; carbon-nitrogen ratio is COD / TN=175.3.

[0118] (2) Corn cob processing: crush, add water to submerge the corn cob, pre-treat the water, heat and soak to remove impurities;

[0119] (3) Mix the treated rice straw, corn cob and rice in proportion, soak in water for 30 minutes, rinse until the water is clear, add water at a rice-to-water ratio of 1:1.3, steam for 30 minutes, and simmer for 10 minutes.

[0120] (4) Rehydration treatment: Take the rice grains after steaming and cooking, place them in boiling water and cover them, and process them by twin-screw extrusion method for 20 minutes.

[0121] In step (1), the composting agent includes Trichoderma reesei, Trichoderma aureoviride, and Bacillus feederii, with an effective viable count of ≥200 million CFU / g.

[0122] In step (1), the mass ratio of composting agent to urea is 1:2.

[0123] In step (1), the moisture content of the rice straw is 60%.

[0124] In step (2), the temperature for heating and soaking is 120℃ and the soaking time is 120min.

[0125] In step (3), the mass ratio of rice straw, corn cob and rice is 1:1:5.

[0126] In step (3), the steaming temperature is 150℃.

[0127] In step (4), the temperature of the twin-screw extrusion process is 120℃, the material moisture content is 30-40%, and the screw speed is 200-500 r / min.

[0128] Example 7

[0129] A method for preparing instant rice made from rice straw and corn cob includes the following steps:

[0130] (1) Rice straw treatment: crush to 2-3cm, remove impurities, add composting agent and urea to adjust carbon-nitrogen ratio, spray water, compost fermentation, temperature is 63℃; carbon-nitrogen ratio is COD / TN=175.8.

[0131] (2) Corn cob processing: crush, add water to submerge the corn cob, pre-treat the water, heat and soak to remove impurities;

[0132] (3) Mix the treated rice straw, corn cob and rice in proportion, soak in water for 30 minutes, rinse until the water is clear, add water at a rice-to-water ratio of 1:1.4, steam for 30 minutes, and simmer for 10 minutes.

[0133] (4) Rehydration treatment: Take the rice grains after steaming and cooking, place them in boiling water and cover them, and process them by twin-screw extrusion method for 20 minutes.

[0134] In step (1), the composting agent includes Trichoderma reesei, Trichoderma aureoviride, and Bacillus feederii, with an effective viable count of ≥200 million CFU / g.

[0135] In step (1), the mass ratio of composting agent to urea is 1:2.

[0136] In step (1), the moisture content of the rice straw is 65%.

[0137] In step (2), the temperature for heating and soaking is 120℃, and the soaking time is 120-160 min.

[0138] In step (3), the mass ratio of rice straw, corn cob and rice is 1:1:5.

[0139] In step (3), the steaming temperature is 150℃.

[0140] In step (4), the temperature of the twin-screw extrusion process is 120℃, the material moisture content is 30%, and the screw speed is 200 r / min.

[0141] Example 8

[0142] A method for preparing instant rice made from rice straw and corn cob includes the following steps:

[0143] (1) Rice straw treatment: crush to 2-3cm, remove impurities, add composting agent and urea to adjust carbon-nitrogen ratio, spray water, compost fermentation, temperature is 60℃; carbon-nitrogen ratio is COD / TN=175.8.

[0144] (2) Corn cob processing: crush, add water to submerge the corn cob, pre-treat the water, heat and soak to remove impurities;

[0145] (3) Mix the treated rice straw, corn cob and rice in proportion, soak in water for 30 minutes, rinse until the water is clear, add water at a rice-to-water ratio of 1:1.5, steam for 30 minutes, and simmer for 10 minutes.

[0146] (4) Rehydration treatment: Take the rice grains after steaming and cooking, place them in boiling water and cover them, and process them by twin-screw extrusion method for 20 minutes.

[0147] In step (1), the composting agent includes Trichoderma reesei, Trichoderma aureoviride, and Bacillus feederii, with an effective viable count of ≥200 million CFU / g.

[0148] In step (1), the mass ratio of composting agent to urea is 1:1.

[0149] In step (1), the moisture content of the rice straw is 60%.

[0150] In step (2), the temperature for heating and soaking is 120℃ and the soaking time is 120min.

[0151] In step (3), the mass ratio of rice straw, corn cob and rice is 1:1:5.

[0152] In step (3), the steaming temperature is 150℃.

[0153] In step (4), the temperature of the twin-screw extrusion process is 120℃, the material moisture content is 30%, and the screw speed is 200 r / min.

[0154] Example 9

[0155] A method for preparing instant rice made from rice straw and corn cob includes the following steps:

[0156] (1) Rice straw treatment: crush to 2-3cm, remove impurities, add composting agent and urea to adjust carbon-nitrogen ratio, spray water, compost fermentation, temperature is 62℃; carbon-nitrogen ratio is COD / TN=175.8.

[0157] (2) Corn cob processing: crush, add water to submerge the corn cob, pre-treat the water, heat and soak to remove impurities;

[0158] (3) Mix the treated rice straw, corn cob and rice in proportion, soak in water for 30 minutes, rinse until the water is clear, add water at a rice-to-water ratio of 1:1.3, steam for 30 minutes, and simmer for 10 minutes.

[0159] (4) Rehydration treatment: Take the rice grains after steaming and cooking, place them in boiling water and cover them, and process them by twin-screw extrusion method for 20 minutes.

[0160] In step (1), the composting agent includes Trichoderma reesei, Trichoderma aureoviride, and Bacillus feederii, with an effective viable count of ≥200 million CFU / g.

[0161] In step (1), the mass ratio of composting agent to urea is 2:1.

[0162] In step (1), the moisture content of the rice straw is 60%.

[0163] In step (2), the temperature for heating and soaking is 120℃ and the soaking time is 120min.

[0164] In step (3), the mass ratio of rice straw, corn cob and rice is 1:1:5.

[0165] In step (3), the steaming temperature is 150℃.

[0166] In step (4), the temperature of the twin-screw extrusion process is 120℃, the material moisture content is 30%, and the screw speed is 200 r / min.

[0167] Example 10

[0168] A method for preparing instant rice made from rice straw and corn cob includes the following steps:

[0169] (1) Rice straw treatment: crush to 2-3cm, remove impurities, add composting agent and urea to adjust carbon-nitrogen ratio, spray water, compost fermentation, temperature is 63℃; carbon-nitrogen ratio is COD / TN=175.2.

[0170] (2) Corn cob processing: crush, add water to submerge the corn cob, pre-treat the water, heat and soak to remove impurities;

[0171] (3) Mix the treated rice straw, corn cob and rice in proportion, soak in water for 30 minutes, rinse until the water is clear, add water at a rice-to-water ratio of 1:1.2, steam for 30 minutes, and simmer for 10 minutes.

[0172] (4) Rehydration treatment: Take the rice grains after steaming and cooking, place them in boiling water and cover them, and process them by twin-screw extrusion method for 20 minutes.

[0173] In step (1), the composting agent includes Trichoderma reesei, Trichoderma aureoviride, and Bacillus feederii, with an effective viable count of ≥200 million CFU / g.

[0174] In step (1), the mass ratio of composting agent to urea is 1:2.

[0175] In step (1), the moisture content of the rice straw is 60%.

[0176] In step (2), the temperature for heating and soaking is 120℃ and the soaking time is 120min.

[0177] In step (3), the mass ratio of rice straw, corn cob and rice is 1:1:5.

[0178] In step (3), the steaming temperature is 150℃.

[0179] In step (4), the temperature of the twin-screw extrusion process is 120℃, the material moisture content is 30%, and the screw speed is 200r / min.

[0180] Example 11

[0181] A method for preparing instant rice made from rice straw and corn cob includes the following steps:

[0182] (1) Rice straw treatment: crush to 2-3cm, remove impurities, add composting agent and urea to adjust carbon-nitrogen ratio, spray water, compost fermentation, temperature is 65℃; carbon-nitrogen ratio is COD / TN=175.8.

[0183] (2) Corn cob processing: crush, add water to submerge the corn cob, pre-treat the water, heat and soak to remove impurities;

[0184] (3) Mix the treated rice straw, corn cob and rice in proportion, soak in water for 30 minutes, rinse until the water is clear, add water at a rice-to-water ratio of 1:1.5, steam for 30 minutes, and simmer for 10 minutes.

[0185] (4) Rehydration treatment: Take the rice grains after steaming and cooking, place them in boiling water and cover them, and process them by twin-screw extrusion method for 20 minutes.

[0186] In step (1), the composting agent includes Trichoderma reesei, Trichoderma aureoviride, and Bacillus feederii, with an effective viable count of ≥200 million CFU / g.

[0187] In step (1), the mass ratio of composting agent to urea is 1:1.

[0188] In step (1), the moisture content of the rice straw is 60%.

[0189] In step (2), the temperature for heating and soaking is 120℃ and the soaking time is 120min.

[0190] In step (3), the mass ratio of rice straw, corn cob and rice is 1:1:6.

[0191] In step (3), the steaming temperature is 155℃.

[0192] In step (4), the temperature of the twin-screw extrusion process is 120℃, the material moisture content is 30%, and the screw speed is 200 r / min.

[0193] Example 12

[0194] A method for preparing instant rice made from rice straw and corn cob includes the following steps:

[0195] (1) Rice straw treatment: crush to 2-3cm, remove impurities, add composting agent and urea to adjust carbon-nitrogen ratio, spray water, compost fermentation, temperature is 65℃; carbon-nitrogen ratio is COD / TN=175.8.

[0196] (2) Corn cob processing: crush, add water to submerge the corn cob, pre-treat the water, heat and soak to remove impurities;

[0197] (3) Mix the treated rice straw, corn cob and rice in proportion, soak in water for 40 minutes, rinse until the water is clear, add water at a rice-to-water ratio of 1:1.2, steam for 30 minutes, and simmer for 20 minutes.

[0198] (4) Rehydration treatment: Take the rice grains after steaming and cooking, place them in boiling water and cover them, and process them by twin-screw extrusion method. The rehydration time is 40 minutes.

[0199] In step (1), the composting agent includes Trichoderma reesei, Trichoderma aureoviride, and Bacillus feederii, with an effective viable count of ≥200 million CFU / g.

[0200] In step (1), the mass ratio of composting agent to urea is 3:1.

[0201] In step (1), the moisture content of the rice straw is 60%.

[0202] In step (2), the temperature for heating and soaking is 120℃ and the soaking time is 120min.

[0203] In step (3), the mass ratio of rice straw, corn cob and rice is 1:2:5.

[0204] In step (3), the steaming temperature is 150℃.

[0205] In step (4), the temperature of the twin-screw extrusion process is 120℃, the material moisture content is 30%, and the screw speed is 200r / min.

[0206] Example 13

[0207] A method for preparing instant rice made from rice straw and corn cob includes the following steps:

[0208] (1) Rice straw treatment: crush to 2-3cm, remove impurities, add composting agent and urea to adjust carbon-nitrogen ratio, spray water, compost fermentation, temperature is 65℃; carbon-nitrogen ratio is COD / TN=175.8.

[0209] (2) Corn cob processing: crush, add water to submerge the corn cob, pre-treat the water, heat and soak to remove impurities;

[0210] (3) Mix the treated rice straw, corn cob and rice in proportion, soak in water for 50 minutes, rinse until the water is clear, add water at a rice-to-water ratio of 1:1.6, steam for 30 minutes, and simmer for 10 minutes.

[0211] (4) Rehydration treatment: Take the rice grains after steaming and cooking, place them in boiling water and cover them, and process them by twin-screw extrusion method for 20 minutes.

[0212] In step (1), the composting agent includes Trichoderma reesei, Trichoderma aureoviride, and Bacillus feederii, with an effective viable count of ≥200 million CFU / g.

[0213] In step (1), the mass ratio of composting agent to urea is 5:1.

[0214] In step (1), the moisture content of the rice straw is 60%.

[0215] In step (2), the temperature for heating and soaking is 120℃ and the soaking time is 120min.

[0216] In step (3), the mass ratio of rice straw, corn cob and rice is 1:1:5.

[0217] In step (3), the steaming temperature is 150℃.

[0218] In step (4), the temperature of the twin-screw extrusion process is 130℃, the material moisture content is 30%, and the screw speed is 200 r / min.

[0219] Example 14

[0220] A method for preparing instant rice made from rice straw and corn cob includes the following steps:

[0221] (1) Rice straw treatment: crush to 2-3cm, remove impurities, add composting agent and urea to adjust carbon-nitrogen ratio, spray water, compost fermentation, temperature is 65℃; carbon-nitrogen ratio is COD / TN=175.8.

[0222] (2) Corn cob processing: crush, add water to submerge the corn cob, pre-treat the water, heat and soak to remove impurities;

[0223] (3) Mix the treated rice straw, corn cob and rice in proportion, soak in water for 30 minutes, rinse until the water is clear, add water at a rice-to-water ratio of 1:1.8, steam for 30 minutes, and simmer for 10 minutes.

[0224] (4) Rehydration treatment: Take the rice grains after steaming and cooking, place them in boiling water and cover them, and process them by twin-screw extrusion method for 20 minutes.

[0225] In step (1), the composting agent includes Trichoderma reesei, Trichoderma aureoviride, and Bacillus feederii, with an effective viable count of ≥200 million CFU / g.

[0226] In step (1), the mass ratio of composting agent to urea is 5:3.

[0227] In step (1), the moisture content of the rice straw is 65%.

[0228] In step (2), the temperature for heating and soaking is 125℃ and the soaking time is 130min.

[0229] In step (3), the mass ratio of rice straw, corn cob and rice is 2:2:5.

[0230] In step (3), the steaming temperature is 160℃.

[0231] In step (4), the temperature of the twin-screw extrusion process is 130℃, the material moisture content is 30%, and the screw speed is 300 r / min.

[0232] Example 15

[0233] A method for preparing instant rice made from rice straw and corn cob includes the following steps:

[0234] (1) Rice straw treatment: crush to 2-3cm, remove impurities, add composting agent and urea to adjust carbon-nitrogen ratio, spray water, compost fermentation, temperature is 65℃; carbon-nitrogen ratio is COD / TN=175.8.

[0235] (2) Corn cob processing: crush, add water to submerge the corn cob, pre-treat the water, heat and soak to remove impurities;

[0236] (3) Mix the treated rice straw, corn cob and rice in proportion, soak in water for 60 minutes, rinse until the water is clear, add water at a rice-to-water ratio of 1:1.8, steam for 60 minutes, and simmer for 20 minutes.

[0237] (4) Rehydration treatment: Take the rice grains after steaming and cooking, place them in boiling water and cover them, and process them by twin-screw extrusion method. The rehydration time is 40 minutes.

[0238] In step (1), the composting agent includes Trichoderma reesei, Trichoderma aureoviride, and Bacillus feederii, with an effective viable count of ≥200 million CFU / g.

[0239] In step (1), the mass ratio of composting agent to urea is 5:3.

[0240] In step (1), the moisture content of the rice straw is 70%.

[0241] In step (2), the temperature for heating and soaking is 135℃ and the soaking time is 160min.

[0242] In step (3), the mass ratio of rice straw, corn cob and rice is 2:3:8.

[0243] In step (3), the steaming temperature is 180℃.

[0244] In step (4), the temperature of the twin-screw extrusion process is 150℃, the material moisture content is 40%, and the screw speed is 500 r / min.

[0245] Comparative Example 1

[0246] A method for preparing instant rice made from rice straw and corn cob includes the following steps:

[0247] (1) Rice straw treatment: crush to 2-3cm, remove impurities, no composting agent is added, only urea is added to adjust the carbon-nitrogen ratio, spray water, compost fermentation, temperature is 60℃;

[0248] (2) Corn cob processing: crush, add water to submerge the corn cob, pre-treat the water, heat and soak to remove impurities;

[0249] (3) Mix the treated rice straw, corn cob and rice in proportion, soak in water for 30 minutes, rinse until the water is clear, add water at a rice-to-water ratio of 1:1.2, steam for 30 minutes, and simmer for 10 minutes.

[0250] (4) Rehydration treatment: Take the rice grains after steaming and cooking, place them in boiling water and cover them, and process them by twin-screw extrusion method for 20 minutes.

[0251] In step (1), the moisture content of the rice straw is 70%.

[0252] In step (2), the temperature for heating and soaking is 120℃ and the soaking time is 120min.

[0253] In step (3), the mass ratio of rice straw, corn cob and rice is 1:1:5.

[0254] In step (3), the steaming temperature is 150℃.

[0255] In step (4), the temperature of the twin-screw extrusion process is 120℃, the material moisture content is 30%, and the screw speed is 200 r / min.

[0256] Comparative Example 2

[0257] A method for preparing instant rice made from rice straw and corn cob includes the following steps:

[0258] (1) Rice straw treatment: crush to 2-3cm, remove impurities, add composting agent, adjust carbon-nitrogen ratio without adding urea, spray water, compost fermentation, temperature is 60℃;

[0259] (2) Corn cob processing: crush, add water to submerge the corn cob, pre-treat the water, heat and soak to remove impurities;

[0260] (3) Mix the treated rice straw, corn cob and rice in proportion, soak in water for 30 minutes, rinse until the water is clear, add water at a rice-to-water ratio of 1:1.2, steam for 30 minutes, and simmer for 10 minutes.

[0261] (4) Rehydration treatment: Take the rice grains after steaming and cooking, place them in boiling water and cover them, and process them by twin-screw extrusion method for 20 minutes.

[0262] In step (1), the moisture content of the rice straw is 60%.

[0263] In step (2), the temperature for heating and soaking is 120℃ and the soaking time is 120min.

[0264] In step (3), the mass ratio of rice straw, corn cob and rice is 1:1:5.

[0265] In step (3), the steaming temperature is 150℃.

[0266] In step (4), the temperature of the twin-screw extrusion process is 120℃, the material moisture content is 30%, and the screw speed is 200 r / min.

[0267] Comparative Example 3

[0268] A method for preparing instant rice made from rice straw and corn cob includes the following steps:

[0269] (1) Rice straw treatment: crush to 2-3cm, remove impurities, without adding composting agent and urea, spray with water, compost fermentation, temperature is 65℃;

[0270] (2) Corn cob processing: crush, add water to submerge the corn cob, pre-treat the water, heat and soak to remove impurities;

[0271] (3) Mix the treated rice straw, corn cob and rice in proportion, soak in water for 30 minutes, rinse until the water is clear, add water at a rice-to-water ratio of 1:1.2, steam for 30 minutes, and simmer for 10 minutes.

[0272] (4) Rehydration treatment: Take the rice grains after steaming and cooking, place them in boiling water and cover them, and process them by twin-screw extrusion method for 20 minutes.

[0273] In step (1), the composting agent includes Trichoderma reesei, Trichoderma aureoviride, and Bacillus feederii, with an effective viable count of ≥200 million CFU / g.

[0274] In step (1), the mass ratio of composting agent to urea is 1:2.

[0275] In step (1), the moisture content of the rice straw is 60%.

[0276] In step (2), the temperature for heating and soaking is 120℃ and the soaking time is 120min.

[0277] In step (3), the mass ratio of rice straw, corn cob and rice is 1:2:5.

[0278] In step (3), the steaming temperature is 150℃.

[0279] In step (4), the temperature of the twin-screw extrusion process is 120℃, the material moisture content is 30%, and the screw speed is 200r / min.

[0280] Comparative Example 4

[0281] A method for preparing instant rice made from rice straw and corn cob includes the following steps:

[0282] (1) Rice straw treatment: crush to 2-3cm, remove impurities, add composting agent and urea to adjust carbon-nitrogen ratio, spray water, compost fermentation, temperature is 65℃; carbon-nitrogen ratio is COD / TN=175.8.

[0283] (2) Corn cob processing: crush, add water to submerge the corn cob, pre-treat the water, heat and soak to remove impurities;

[0284] (3) Mix the treated rice straw, corn cob and rice in proportion, soak in water for 20 minutes, rinse until the water is clear, add water at a rice-to-water ratio of 1:1, steam for 20 minutes, and simmer for 5 minutes.

[0285] (4) Rehydration treatment: Take the rice grains after steaming and cooking, place them in boiling water and cover them, and process them by twin-screw extrusion method. The rehydration time is 10 minutes.

[0286] In step (1), the composting agent includes Trichoderma reesei, Trichoderma aureoviride, and Bacillus feederii, with an effective viable count of ≥200 million CFU / g.

[0287] In step (1), the mass ratio of composting agent to urea is 1:2.

[0288] In step (1), the moisture content of the rice straw is 60%.

[0289] In step (2), the temperature for heating and soaking is 120℃ and the soaking time is 120min.

[0290] In step (3), the mass ratio of rice straw, corn cob and rice is 1:1:5.

[0291] In step (3), the steaming temperature is 150℃.

[0292] In step (4), the temperature of the twin-screw extrusion process is 120℃, the material moisture content is 30%, and the screw speed is 200r / min.

[0293] The above description is merely an exemplary embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method for preparing instant rice made from rice straw and corn cob, characterized in that, Includes the following steps: (1) Rice straw treatment: crush, remove impurities, add composting agent and urea to adjust carbon-nitrogen ratio, spray water, compost fermentation, temperature is 60-65℃; (2) Corn cob processing: crush, add water to submerge the corn cob, pre-treat the water, heat and soak to remove impurities; (3) Mix the treated rice straw, corn cob and rice in proportion, soak in water for 30-60 minutes, rinse until the water is clear, add water at a rice-to-water ratio of 1:1.2-1.8, steam for 30-60 minutes, and simmer for 10-20 minutes. (4) Rehydration treatment: Take the rice grains after steaming and cooking, put them in boiling water and cover them, and process them by twin-screw extrusion method. The rehydration time is 20-40 minutes.

2. The method for preparing instant rice made from rice straw and corn cob according to claim 1, characterized in that, In (1), the composting agent includes Trichoderma reesei, Trichoderma aureoviride, and Bacillus feederii, with a total bacterial count ≥ 200 million CFU / g.

3. The method for preparing instant rice made from rice straw and corn cob according to claim 1, characterized in that, In (1), the mass ratio of the composting agent to the urea is 1-5:1-3.

4. The method for preparing instant rice made from rice straw and corn cob according to claim 1, characterized in that, In (1), the moisture content of the rice straw is 60-70%.

5. The method for preparing instant rice made from rice straw and corn cob according to claim 1, characterized in that, In step (2), the temperature of the heating and soaking is 120-135℃, and the soaking time is 120-160min.

6. The method for preparing instant rice made from rice straw and corn cob according to claim 1, characterized in that, In (3), the mass ratio of rice straw, corn cob and rice is 1-2:1-3:5-8.

7. The method for preparing instant rice made from rice straw and corn cob according to claim 1, characterized in that, In step (3), the steaming temperature is 150-180℃.

8. The method for preparing instant rice made from rice straw and corn cob according to claim 1, characterized in that, In (4), the temperature of the twin-screw extrusion process is 120-150℃, the material moisture content is 30-40%, and the screw speed is 200-500 r / min.