Rice flour with delayed lipid oxidation rancidity node and preparation method thereof

Abstract

This invention relates to the field of rice flour preparation, specifically to rice flour production. The method involves roasting paddy rice at 120-140°C, followed by hulling to obtain roasted rice. The roasted rice is then pulverized to obtain the rice flour. This invention employs a process of roasting, hulling, and grinding to delay the lipid oxidation and rancidity of rice flour, thus extending its shelf life. Simultaneously, the resulting raw rice flour can be enhanced by high-temperature roasting to produce a unique caramelized aroma from the paddy rice itself. This flavor significantly improves the texture and aroma distinctiveness of the rice flour. Directly roasting the paddy rice simplifies the process, saving processing time, reducing costs, and increasing production efficiency.

Description

Technical Field

[0001] This invention relates to the field of rice flour preparation, specifically to a rice flour with delayed lipid oxidation and rancidity and its preparation method. Background Technology

[0002] During storage, rice and its processed products (such as rice flour) are prone to oxidative rancidity due to the susceptibility of their lipid components to oxygen and moisture in the environment, gradually producing a pungent "rancid" odor. This off-odor not only severely damages the flavor and sensory quality of rice flour, leading to a significant decrease in its edible value, but more importantly, the lipid oxidation process is accompanied by the continuous accumulation of harmful oxidation products such as aldehydes and ketones. Long-term intake of these substances may pose potential health risks to the human digestive and metabolic systems. Furthermore, lipid oxidative rancidity accelerates the deterioration of rice flour quality, significantly shortening its shelf life and causing substantial economic losses in production, storage, and sales. Therefore, how to delay the onset of lipid oxidative rancidity in rice flour has become a critical technical problem that urgently needs to be solved in the industry.

[0003] Existing technologies have been researched regarding the processing of rice flour. For example, Chinese invention patent application number 201711192516.0 discloses a processing method for edible rice flour, the specific steps of which include material selection, drying, hulling, dust removal, roasting, grinding, screening, and packaging. This process imparts a unique caramelized flavor to the rice through roasting, which has certain advantages in terms of sensory optimization. However, the high-temperature environment during roasting can damage the stability of lipids in the rice, accelerate the oxidation and deterioration of internal unsaturated fatty acids, and exacerbate the formation of a rancid taste during subsequent storage, failing to solve the problem of lipid oxidative rancidity.

[0004] Another related technology can be found in Chinese invention patent application number 201410391495.5, which discloses a rice flour processing technology and methods for preparing parboiled rice flour, oat parboiled rice flour, and oat rice flour. The process flow covers raw material washing, soaking, steaming, aging, drying, dehulling, grinding into powder, shaping, and post-processing. The innovation of this technology lies in promoting the transfer of vitamins, minerals, and other nutrients from the inner layer of the rice husk to the rice endosperm through soaking and steaming of the husk-covered grains, thereby enhancing the nutritional value of the rice flour. However, this process does not design specific protective measures for the lipid components in rice. During storage, the lipids in the prepared rice flour are still prone to reacting with environmental factors, and the problem of oxidative rancidity remains prominent, failing to meet the market demand for long-term stable storage of rice flour. Summary of the Invention

[0005] To address the problem of lipid oxidation and rancidity in rice flour in existing technologies, this invention provides rice flour that delays the lipid oxidation and rancidity process and its preparation method.

[0006] To achieve the above objectives, the specific solution adopted by the present invention is as follows: a method for preparing rice flour that delays lipid oxidation and rancidity, wherein rice is baked at an ambient temperature of 120-140℃ and then dehulled to obtain baked rice, and the baked rice is pulverized to obtain the rice flour.

[0007] As a further optimization of the above technical solution: the baking time is 1-3 hours.

[0008] As a further optimization of the above technical solution: the moisture content of the rice is 10-15%.

[0009] As a further optimization of the above technical solution: the moisture content of the baked rice is 2-5%.

[0010] As a further optimization of the above technical solution: the baking temperature is 130℃ and the baking time is 3 hours.

[0011] As a further optimization of the above technical solution: roasted rice is ground and pulverized using a grinder, and the pulverized powder is passed through a 100-mesh filter to obtain the rice flour.

[0012] As a further optimization of the above technical solution: the rice refers to rice harvested within the current year.

[0013] As a further optimization of the above technical solution: the rice grains are plump and free of mold on the outside.

[0014] As a further optimization of the above technical solution: the roasted rice is cooled to room temperature before hulling, and the cooling time is ≤30min.

[0015] Rice flour prepared by the above method.

[0016] Compared with the prior art, the present invention has the following beneficial effects: This invention employs a process of baking, dehulling, and grinding to delay the lipid oxidation and rancidity of rice flour, slow down the onset of rancidity, and extend the shelf life of the product. At the same time, the baking process can stimulate the rice itself to produce a unique caramel aroma through high temperature, which can significantly enhance the texture and aroma of the rice flour.

[0017] Because the rice husk retains its protective function during the baking stage, the rice husk, as a dense fibrous structure, can form a physical barrier during high-temperature baking. On the one hand, it reduces the loss of antioxidant components and flavor substances such as oryzanol and tocopherol inside the rice due to high-temperature volatilization, maintaining the rice's own antioxidant capacity. On the other hand, it prevents the rice grains from being directly exposed to the high-temperature environment, reducing the risk of excessive scorching on the surface. At the same time, it reduces the direct contact between the grains and oxygen at high temperatures, slowing down the lipid oxidation and decomposition during the baking stage from the source, thereby delaying the lipid oxidation and rancidity of rice flour and slowing down the appearance of rancid oil. Attached Figure Description

[0018] Figure 1 The rancidity of different samples was observed after baking for 1 hour and storing them at room temperature for 175 days. Figure 2 The rancidity of different samples was observed after baking for 2 hours and storing at room temperature for 175 days. Figure 3 The rancidity of different samples was observed after baking for 3 hours and storing at room temperature for 175 days. Figure 4 The rancidity of different samples was observed after baking for 1 hour and storing them at 42℃ for 175 days. Figure 5 The rancidity of different samples was observed after baking for 2 hours and storing them at 42℃ for 175 days. Figure 6 The rancidity of different samples was observed after baking for 3 hours and storing them at 42℃ for 175 days. Detailed Implementation

[0019] The technical solution of the present invention will be further described in detail below with reference to specific embodiments. Parts not described or disclosed in detail in the following embodiments of the present invention should be understood as prior art known or should be known by those skilled in the art.

[0020] Example 1 A method for preparing rice flour with delayed lipid oxidative rancidity includes the following steps: S1. Select fresh rice harvested this year that is plump, uniform in size, free from mold, insect infestation, and damage; place the rice in a clean drying yard with good ventilation and sufficient sunlight for natural drying, turning it over every 2-3 hours to ensure that the moisture content of the rice drops evenly to 10-15%; then send the dried rice into a pulse dust removal device to remove surface dust, impurities, and shriveled grains to obtain clean raw rice for later use. S2. The selected rice grains are baked at 120℃ for 1 hour. S3. Cool the roasted rice to room temperature for 30 minutes to prevent further oxidation from residual heat, then send it to a rice hulling machine for hulling; separate the rice husks from the rice, and collect the hull-free roasted rice; the moisture content of the roasted rice is 4.9%; S4. Grind the roasted rice using a grinder; S5. The ground powder is screened through a 100-mesh filter. The material that passes through the sieve is the rice flour that meets the requirements. The coarse particles remaining on the sieve are returned to S4 for re-grinding to improve the utilization rate of raw materials.

[0021] Example 2 The overall steps in this embodiment are the same as in Embodiment 1, except that in this embodiment: Step S2: Roast the selected rice as raw material at 120℃ for 2 hours; S3. Cool the roasted rice to room temperature for 30 minutes to prevent further oxidation from residual heat, then send it to a rice hulling machine for hulling; separate the rice husks from the rice, and collect the hull-free roasted rice; the moisture content of the roasted rice is 4.3%; The other steps are the same as in Example 1.

[0022] Example 3 The overall steps in this embodiment are the same as in Embodiment 1, except that: In this embodiment, step S2: the selected rice as raw material is baked at 120°C for 3 hours; S3. Cool the roasted rice to room temperature for 30 minutes to prevent further oxidation from residual heat, then send it to a rice hulling machine for hulling; separate the rice husks from the rice, and collect the hull-free roasted rice; the moisture content of the roasted rice is 3.6%; The other steps are the same as in Example 1.

[0023] Example 4 The overall steps in this embodiment are the same as in Embodiment 1, except that: In this embodiment, step S2: the selected rice as raw material is baked at 130°C for 1 hour; S3. Cool the roasted rice to room temperature for 30 minutes to prevent further oxidation from residual heat, then send it to a rice hulling machine for hulling; separate the rice husks from the rice, and collect the hull-free roasted rice; the moisture content of the roasted rice is 3.7%; The other steps are the same as in Example 1.

[0024] Example 5 The overall steps in this embodiment are the same as in Embodiment 1, except that: In this embodiment, step S2: the selected rice as raw material is baked at 130°C for 2 hours; S3. Cool the roasted rice to room temperature for 30 minutes to prevent further oxidation from residual heat, then send it to a rice hulling machine for hulling; separate the rice husks from the rice, and collect the hull-free roasted rice; the moisture content of the roasted rice is 3.3%; The other steps are the same as in Example 1.

[0025] Example 6 The overall steps in this embodiment are the same as in Embodiment 1, except that: In this embodiment, step S2: the selected rice as raw material is baked at 130°C for 3 hours; S3. Cool the roasted rice to room temperature for 30 minutes to prevent further oxidation from residual heat, then send it to a rice hulling machine for hulling; separate the rice husks from the rice, and collect the hull-free roasted rice; the moisture content of the roasted rice is 2.4%; The other steps are the same as in Example 1.

[0026] Example 7 The overall steps in this embodiment are the same as in Embodiment 1, except that: In this embodiment, step S2: the selected rice as raw material is baked at 140°C for 1 hour; S3. Cool the roasted rice to room temperature for 30 minutes to prevent further oxidation from residual heat, then send it to a rice hulling machine for hulling; separate the rice husks from the rice, and collect the hull-free roasted rice; the moisture content of the roasted rice is 3.1%; The other steps are the same as in Example 1.

[0027] Example 8 The overall steps in this embodiment are the same as in Embodiment 1, except that: In this embodiment, step S2: the selected rice as raw material is baked at 140°C for 2 hours; S3. Cool the roasted rice to room temperature for 30 minutes to prevent further oxidation from residual heat, then send it to a rice hulling machine for hulling; separate the rice husks from the rice, and collect the hull-free roasted rice; the moisture content of the roasted rice is 2.7%; The other steps are the same as in Example 1.

[0028] Example 9 The overall steps in this embodiment are the same as in Embodiment 1, except that: In this embodiment, step S2: the selected rice as raw material is baked at 140°C for 3 hours; S3. Cool the roasted rice to room temperature for 30 minutes to prevent further oxidation from residual heat, then send it to a rice hulling machine for hulling; separate the rice husks from the rice, and collect the hull-free roasted rice; the moisture content of the roasted rice is 2.3%; The other steps are the same as in Example 1.

[0029] Comparative Example 1 A method for preparing rice noodles includes the following steps: S1: Obtain clean raw rice with a moisture content of 10-15% according to the method in step S1 of Example 1, and set it aside; S2. Feed the raw paddy rice into the paddy rice dehulling machine for dehulling; separate the paddy husk from the rice and collect the hull-free rice. S3. Roast the rice at 130℃ for 1 hour to obtain roasted rice. Cool the roasted rice to room temperature for 30 minutes to prevent further oxidation from residual heat. The moisture content of the roasted rice is 2.9%. S4. Grind the roasted rice using a grinder; S5. Screen the ground powder through a 100-mesh filter. The material that passes through the sieve is the rice flour that meets the requirements.

[0030] Comparative Example 2 A method for preparing rice noodles includes the following steps: S1: Obtain clean raw rice with a moisture content of 10-15% according to the method in step S1 of Example 1, and set it aside; S2. Feed the raw paddy rice into the paddy rice dehulling machine for dehulling; separate the paddy husk from the rice and collect the hull-free rice. S3. Roast the rice at 130℃ for 2 hours to obtain roasted rice. Cool the roasted rice to room temperature for 30 minutes to prevent further oxidation from residual heat. The moisture content of the roasted rice is 1.1%. S4. Grind the roasted rice using a grinder; S5. Screen the ground powder through a 100-mesh filter. The material that passes through the sieve is the rice flour that meets the requirements.

[0031] Comparative Example 3 A method for preparing rice noodles includes the following steps: S1: Obtain clean raw rice with a moisture content of 10-15% according to the method in step S1 of Example 1, and set it aside; S2. Feed the raw paddy rice into the paddy rice dehulling machine for dehulling; separate the paddy husk from the rice and collect the hull-free rice. S3. Roast the rice at 130℃ for 3 hours to obtain roasted rice. Cool the roasted rice to room temperature for 30 minutes to prevent further oxidation from residual heat. The moisture content of the roasted rice is 0.7%. S4. Grind the roasted rice using a grinder; S5. Screen the ground powder through a 100-mesh filter. The material that passes through the sieve is the rice flour that meets the requirements.

[0032] Comparative Example 4 A method for preparing rice noodles includes the following steps: S1: Obtain clean raw rice with a moisture content of 10-15% according to the method in step S1 of Example 1, and set it aside; S2. Feed the raw paddy rice into the paddy rice dehulling machine for dehulling; separate the paddy husk from the rice and collect the hull-free rice. S3. Roast the rice at 110℃ for 3 hours to obtain roasted rice with a moisture content of 4.4%. S4. Cool the roasted rice to room temperature for 30 minutes to prevent continued oxidation from residual heat. S4. Grind the roasted rice using a grinder; S5. Screen the ground powder through a 100-mesh filter. The material that passes through the sieve is the rice flour that meets the requirements.

[0033] Comparative Example 5 A method for preparing rice noodles includes the following steps: S1: Obtain clean raw rice with a moisture content of 10-15% according to the method in step S1 of Example 1, and set it aside; S2. Feed the raw paddy rice into the paddy rice dehulling machine for dehulling; separate the paddy husk from the rice and collect the hull-free rice. S3. Roast the rice at 150℃ for 1 hour to obtain roasted rice with a moisture content of 1.0%. S4. Cool the roasted rice to room temperature for 30 minutes. S4. Grind the roasted rice using a grinder; S5. Screen the ground powder through a 100-mesh filter. The material that passes through the sieve is the rice flour that meets the requirements.

[0034] Comparative Example 6 A method for preparing rice noodles includes the following steps: Step 1: Select rice that is free from insects, mold, and spoilage, with a moisture content of 10-13%. Step 2: Baking. Bake the selected rice at 70-90℃ for 10-15 minutes until the moisture content is 8-10%, then bake at 130℃ for 1 hour. Step 3: Grinding. Grind the roasted rice using a grinder. Step 4: Sifting. The ground rice flour is sieved through a 100-mesh filter to obtain rice flour.

[0035] Comparative Example 7 A method for preparing rice noodles includes the following steps: Step 1: Select rice that is free from insects, mold, and spoilage, with a moisture content of 10-13%. Step 2: Baking. Bake the selected rice at 70-90℃ for 10-15 minutes until the moisture content is 8-10%, then bake at 130℃ for 2 hours. Step 3: Grinding. Grind the roasted rice using a grinder. Step 4: Sifting. The ground rice flour is sieved through a 100-mesh filter to obtain rice flour.

[0036] Comparative Example 8 A method for preparing rice noodles includes the following steps: Step 1: Select rice that is free from insects, mold, and spoilage, with a moisture content of 10-13%. Step 2: Baking. Bake the selected rice at 70-90℃ for 10-15 minutes until the moisture content is 8-10%, then bake at 130℃ for 3 hours. Step 3: Grinding. Grind the roasted rice using a grinder. Step 4: Sifting. The ground rice flour is sieved through a 100-mesh filter to obtain rice flour.

[0037] Comparative Example 9 A method for preparing rice noodles includes the following steps: Step 1: Select rice that is free from insects, mold, and spoilage. Moisture content should be 10-13%. Step 2: Washing. Rinse the selected rice as raw material with distilled water 3-4 times and drain the surface water. Step 3: Baking. Bake the washed rice at 70-90℃ for 10-15 minutes until the moisture content is 8-10%, then bake at 130℃ for 1 hour. Step 4: Grinding. Grind the roasted rice using a grinder. Step 5: Sifting. The ground rice flour is sieved through a 100-mesh filter to obtain rice flour.

[0038] Comparative Example 10 A method for preparing rice noodles includes the following steps: Step 1: Select rice that is free from insects, mold, and spoilage. Moisture content should be 10-13%. Step 2: Washing. Rinse the selected rice as raw material with distilled water 3-4 times and drain the surface water. Step 3: Baking. Bake the washed rice at 70-90℃ for 10-15 minutes until the moisture content is 8-10%, then bake at 130℃ for 2 hours. Step 4: Grinding. Grind the roasted rice using a grinder. Step 5: Sifting. The ground rice flour is sieved through a 100-mesh filter to obtain rice flour.

[0039] Comparative Example 11 A method for preparing rice noodles includes the following steps: Step 1: Select rice that is free from insects, mold, and spoilage. Moisture content should be 10-13%. Step 2: Washing. Rinse the selected rice as raw material with distilled water 3-4 times and drain the surface water. Step 3: Baking. Bake the washed rice at 70-90℃ for 10-15 minutes until the moisture content is 8-10%, then bake at 130℃ for 3 hours. Step 4: Grinding. Grind the roasted rice using a grinder. Step 5: Sifting. The ground rice flour is sieved through a 100-mesh filter to obtain rice flour.

[0040] Comparative Example 12 A method for preparing rice noodles includes the following steps: Step 1: Select rice that is free from insects, mold, and spoilage. Moisture content should be 10-13%. Step 2: Alkaline washing. Rinse the selected rice as raw material with a pH=10 Na2CO3 solution 3-4 times and drain the surface water. Step 3: Baking. Baking the rice that has been washed with alkali at 70-90℃ for 10-15 minutes until the moisture content is 8-10%, and then baking at 130℃ for 1 hour. Step 4: Grinding. Grind the roasted rice using a grinder. Step 5: Sifting. The ground rice flour is sieved through a 100-mesh filter to obtain rice flour.

[0041] Comparative Example 13 A method for preparing rice noodles includes the following steps: Step 1: Select rice that is free from insects, mold, and spoilage. Moisture content should be 10-13%. Step 2: Alkaline washing. Rinse the selected rice as raw material with a pH=10 Na2CO3 solution 3-4 times and drain the surface water. Step 3: Baking. Baking the rice that has been washed with alkali at 70-90℃ for 10-15 minutes until the moisture content is 8-10%, and then baking at 130℃ for 2 hours. Step 4: Grinding. Grind the roasted rice using a grinder. Step 5: Sifting. The ground rice flour is sieved through a 100-mesh filter to obtain rice flour.

[0042] Comparative Example 14 A method for preparing rice noodles includes the following steps: Step 1: Select rice that is free from insects, mold, and spoilage. Moisture content should be 10-13%. Step 2: Alkaline washing. Rinse the selected rice as raw material with a pH=10 Na2CO3 solution 3-4 times and drain the surface water. Step 3: Baking. Baking the rice that has been washed with alkali at 70-90℃ for 10-15 minutes until the moisture content is 8-10%, and then baking at 130℃ for 3 hours. Step 4: Grinding. Grind the roasted rice using a grinder. Step 5: Sifting. The ground rice flour is sieved through a 100-mesh filter to obtain rice flour.

[0043] The rice flour prepared in the examples and comparative examples was placed in 100ml centrifuge tubes and stored at room temperature (about 25°C) and constant temperature at 42°C, respectively.

[0044] Observation time points: Starting from the 1st day of storage, observe the rancidity of the oil at time points of 1d, 3d, 5d, 7d, 9d, 11d, 13d, 15d, 17d, 19d, 21d, 23d, 25d... and test all samples simultaneously at each time point.

[0045] Determination of rancid odor in oil: The experimenter conducts sensory tests on the samples every other day, shaking the centrifuge tube three times each time, opening the lid and smelling the odor to determine whether the sample has developed a rancid odor in oil.

[0046] The results are shown in Tables 1-1, 1-2, 1-3, 2-1, 2-2, and 2-3: Table 1-1 Observation of rancidity in different samples after 175 days of storage at room temperature Table 1-2 Observation of rancidity in different samples after 175 days of storage at room temperature Table 1-3 Observation of rancidity in different samples after 175 days of storage at room temperature Table 2-1 Observation of rancidity in different samples stored at 42℃ for 175 days Table 2-2 Observation of rancidity in different samples stored at 42℃ for 175 days Table 2-3 Observation of rancidity in different samples stored at 42℃ for 175 days Results analysis: Compared with Examples 4-6, Comparative Examples 1-3 differ in that Examples 4-6 involve baking paddy rice, while Comparative Examples 1-3 involve baking rice obtained by dehulling paddy rice. The test results show that the present invention uses a process of baking before dehulling and then milling to delay the lipid oxidation and rancidity of rice flour. This is presumably due to the protective effect of retaining the rice husk during the baking stage. As a dense fibrous structure, the rice husk forms a physical barrier during high-temperature baking. On the one hand, it reduces the high-temperature volatilization loss of antioxidant components such as oryzanol and tocopherol, as well as flavor substances, within the rice, maintaining the rice's inherent antioxidant capacity. On the other hand, it prevents the rice grains from being directly exposed to a high-temperature environment, reducing the risk of excessive scorching on the surface, and also reduces the direct contact between the grains and oxygen at high temperatures, thus slowing down lipid oxidation and decomposition at the source during the baking stage.

[0047] In the process of dehulling, baking, and milling in Comparative Examples 1-3, the dehulled rice is in direct contact with hot air, and the surface fat and protein are completely exposed to the high-temperature oxygen environment. This not only makes it easy for the rice to oxidize and become rancid due to the high temperature, but also causes the loss of antioxidant components due to the lack of rice husk protection, further weakening the rice flour's ability to resist lipid oxidation. Therefore, the process of baking and dehulling in this invention effectively delays the occurrence of lipid oxidation and rancidity in subsequent storage and processing by retaining the antioxidant components inside the rice through the rice husk and reducing oxidative contact.

[0048] This invention directly roasts rice, and the resulting raw rice flour can stimulate the rice itself to produce a unique caramel aroma through high temperature. This flavor can significantly enhance the texture and aroma of the rice flour. In contrast, some existing technologies require soaking, steaming, and then hulling the rice. During this process, the water dilutes or masks the original aroma of the rice, and the steaming temperature is difficult to reach the conditions for producing a caramel flavor. At the same time, steaming turns the rice into cooked rice flour, and its molecular structure (such as starch and protein structure) is destroyed by high-temperature hydration, further losing the material basis for producing a caramel flavor and thus failing to form this unique flavor.

[0049] This invention's direct roasting method allows rice to quickly reach a low moisture content of 2-5%, which, on the one hand, is unfavorable for microbial growth and reproduction, reducing the decomposition of fats by microbial metabolism; on the other hand, it can more thoroughly inactivate the activity of pro-oxidative enzymes such as lipases, delaying fat oxidative rancidity from both enzymatic oxidation and microbial oxidation perspectives. Although existing technologies include a drying step, the soaking and cooking processes introduce a large amount of water first. Subsequent drying not only makes it difficult to control the moisture content at a low level comparable to direct roasting, but the inactivation effect of cooking on enzymes is also weak, failing to completely block the enzymatic oxidation pathway, leading to a higher risk of oxidative rancidity during subsequent storage.

[0050] The present invention simplifies the baking process by directly selecting rice grains, which not only saves processing time but also reduces processing costs and improves production efficiency.

[0051] This invention observes the development of rancid oil odor in rice after different pretreatments under varying baking times (1h, 2h, 3h) and storage conditions (room temperature, 42℃). The longer the baking time, the faster the rate of oil oxidation in the rice flour during subsequent storage. Under baking conditions of 130℃, alkaline washing with a pH=10 Na2CO3 solution effectively delayed lipid oxidation, showing better results than water washing and unwashed treatment. This may be because alkaline washing removes impurities on the rice surface that easily trigger oil oxidation, reducing the oxidation reaction and thus prolonging the time before rancid oil odor appears. High-temperature storage at 42℃ significantly accelerated lipid oxidation in the rice flour, with all samples exhibiting a higher degree of rancid oil odor than the room-temperature storage group. Therefore, in actual rice flour storage, controlling the low-temperature environment can be an important measure to delay oil oxidation and extend the product's shelf life.

[0052] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for preparing rice flour that delays lipid oxidative rancidity, characterized in that: Baked rice is obtained by baking rice at an ambient temperature of 120-140℃ and then removing the husk. The baked rice is then pulverized to obtain the rice flour.

2. The method for preparing rice flour with delayed lipid oxidative rancidity according to claim 1, characterized in that: Baking time is 1-3 hours.

3. The method for preparing rice flour with delayed lipid oxidative rancidity according to claim 1, characterized in that: The moisture content of rice is 10-15%.

4. The method for preparing rice flour with delayed lipid oxidative rancidity according to claim 1, characterized in that: The moisture content of baked rice is 2-5%.

5. The method for preparing rice flour with delayed lipid oxidative rancidity according to claim 1, characterized in that: The baking temperature is 130℃ and the baking time is 3 hours.

6. The method for preparing rice flour with delayed lipid oxidative rancidity according to claim 1, characterized in that: Baked rice is ground and pulverized using a grinder, and the resulting powder is then passed through a 100-mesh filter to obtain the rice flour.

7. The method for preparing rice flour with delayed lipid oxidative rancidity according to claim 1, characterized in that: Rice refers to rice harvested within the current year.

8. The method for preparing rice flour with delayed lipid oxidative rancidity according to claim 1, characterized in that: The rice grains are plump and free of mold.

9. The method for preparing rice flour with delayed lipid oxidative rancidity according to claim 1, characterized in that: After roasting, the rice should be cooled to room temperature before hulling. The cooling time should be ≤30 minutes.

10. Rice flour prepared by the preparation method according to any one of claims 1-9.

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