Rice or corn fatty acid extract, and preparation method and application thereof

Abstract

The application provides a rice or corn fatty acid extraction solution and a preparation method and application thereof, and relates to the technical field of grain fatty acid value detection. The application mixes the pulverized and uniformly mixed rice sample or corn sample with anhydrous ethanol according to a predetermined material-liquid ratio, uses vortex oscillation to promote the fatty acid in the sample to enter the anhydrous ethanol, and uses centrifugation to separate the extraction solution from the sample powder after vortex oscillation, so that the vortex oscillation is used to replace the reciprocating oscillation, and the centrifugal separation is used to replace the funnel and filter paper filtering, the sample pretreatment process of the rice or corn fatty acid value detection is simplified, the batch sample processing efficiency is improved, and the application has a good application prospect in the field of grain storage quality detection and related sample pretreatment.

Description

Technical Field

[0001] This invention relates to the field of grain fatty acid value detection technology, and in particular to a fatty acid extract from rice or corn, its preparation method, and its application. Background Technology

[0002] Fatty acid value is one of the indicators for evaluating the storage quality of grains such as rice and corn. Before determining the fatty acid value, it is usually necessary to crush the grain sample and then extract the fatty acids from the sample using anhydrous ethanol to obtain an extract for subsequent testing. Current extraction processes typically use reciprocating shaking to bring the sample into contact with anhydrous ethanol, followed by filtration through a funnel and filter paper to separate the extract from the sample powder. This method requires relatively independent shaking and filtration steps, resulting in a long sample processing time. Furthermore, the filtration process requires the use of funnels, filter paper, and collection containers, which is not conducive to simplifying the operation process or improving the pretreatment efficiency of batch samples.

[0003] Chinese patent application CN106383200A discloses a method for determining the fatty acid value in corn. This method involves mixing a corn sample with anhydrous ethanol, shaking for 9-20 minutes, filtering, collecting the filtrate, and then titrating the filtrate. While this method improves the extraction and determination process of corn fatty acids, it still employs a solid-liquid separation method of shaking followed by filtration for sample pretreatment, requiring the use of appropriate filtration equipment.

[0004] Patent CN102492542A discloses a rapid extraction method for tiger nut oil. The method involves adding an organic solvent to tiger nut powder at a specific material-to-liquid ratio, vortexing to extract the oil into the organic solvent, and then centrifuging to obtain the extract. This patent demonstrates that vortexing and centrifugation can be used to extract oil from plant materials, but its extraction target is tiger nut oil, and its purpose is to prepare oil products. The raw materials, extraction solvent, and subsequent concentration process used are different from the sample pretreatment for determining the fatty acid value of rice or corn. It does not address how to use vortexing and centrifugation to prepare an extract suitable for determining the fatty acid value of rice or corn.

[0005] Chinese patent application CN111307549A discloses a method for rapidly extracting multiple elements from grains. This method involves mixing a pulverized grain sample with an extractant and extracting inorganic elements from the grain through mechanical oscillation, including vortex oscillation. Insoluble substances are then removed by settling, centrifugation, or filtration. This method targets inorganic elements in grains and uses reduced glutathione solution or cysteine ​​hydrochloride solution as the extractant, which differs from the technical purpose and extraction system used for extracting fatty acids from rice or corn using anhydrous ethanol.

[0006] Therefore, although existing technologies have covered the determination of fatty acid value of corn, vortex extraction of plant materials, and oscillation and centrifugation of grain samples, it is still necessary to provide a method for preparing fatty acid extract that can replace reciprocating oscillation with vortex oscillation and replace funnel and filter paper filtration with centrifugation for the sample pretreatment process of determining fatty acid value of rice or corn. This would shorten the oscillation process, simplify the solid-liquid separation operation, and meet the requirements for the use of extract for fatty acid value determination. Summary of the Invention

[0007] In view of this, the present invention provides a fatty acid extract from rice or corn, its preparation method, and its application. The present invention involves mixing a crushed and homogenized rice or corn sample with anhydrous ethanol according to a predetermined material-to-liquid ratio. Vortex oscillation is used to promote the entry of fatty acids from the sample into the anhydrous ethanol. After vortex oscillation, centrifugation is used to separate the extract from the sample powder. This achieves the replacement of reciprocating oscillation with vortex oscillation and the replacement of funnel and filter paper filtration with centrifugation. It simplifies the sample pretreatment process for detecting fatty acid values ​​in rice or corn and improves the efficiency of batch sample processing. It has promising application prospects in the fields of grain storage quality testing and related sample pretreatment.

[0008] The first aspect of this invention provides a method for preparing a fatty acid extract from rice or corn, comprising the following steps: The rice sample was dehulled, while the corn sample was not dehulled. The rice or corn sample was crushed and mixed, and the resulting sample was placed in a centrifuge tube with anhydrous ethanol added. The capped centrifuge tube was placed on the centrifuge rack of a vortex mixer and vortexed at a speed of 4000 rpm. The vortex mixer was used for 5 min when the sample was rice and for 10 min when the sample was corn. The vortexed centrifuge tube was then centrifuged in a centrifuge with a maximum speed of 5000 rpm for 3 min to obtain the fatty acid extract.

[0009] Preferably, the mass ratio of the rice or corn sample to the volume of anhydrous ethanol is 1 g: 5 mL.

[0010] Preferably, the proportion of the pulverized sample passing through the CQ16 sieve in one pass is above 95%.

[0011] Preferably, the mixing is performed using a mixer or manually.

[0012] Preferably, the anhydrous ethanol is added to the centrifuge tube using a pipette or a bottle-top dispenser.

[0013] Preferably, the vortex oscillator has a control device for setting the oscillation mode, oscillation frequency, and oscillation time.

[0014] Preferably, the centrifuge tubes are fixed on the centrifuge rack in a horizontal arrangement.

[0015] A second aspect of the present invention provides a fatty acid extract of rice or corn prepared by the above method.

[0016] A third aspect of the present invention provides the application of the fatty acid extract in the determination of fatty acid values ​​in rice or corn.

[0017] Compared with the prior art, the beneficial technical effects of the present invention are as follows: This invention employs vortex oscillation to ensure sufficient contact between rice or corn samples and anhydrous ethanol. Compared to reciprocating oscillation, vortex oscillation generates more vigorous liquid movement, which facilitates the transfer of fatty acids from the sample into the anhydrous ethanol. This results in an extract suitable for fatty acid value determination within a shorter oscillation time, thus shortening the processing time required for sample extraction.

[0018] This invention separates the extract from the sample powder by centrifugation after vortex oscillation. Centrifugation replaces the use of funnels and filter paper for filtration, eliminating the need for filter paper installation, filtration, and filtrate collection. This reduces reliance on filter materials such as funnels, filter paper, and colorimetric tubes, simplifies the preparation process of fatty acid extract, and facilitates continuous processing of batches of samples.

[0019] This invention determines the amount of anhydrous ethanol to be added based on the material-liquid ratio between the sample mass and the volume of anhydrous ethanol, and sets vortex oscillation conditions for rice and corn samples respectively, so that the sample amount, extractant amount and oscillation process are correlated, which helps to standardize the preparation of fatty acid extract and improve the consistency of the pretreatment process of different batches of samples.

[0020] The extract obtained using the method of this invention can be used for subsequent determination of fatty acid values ​​in rice or corn. This invention combines vortex extraction with centrifugation for sample pretreatment in grain fatty acid value detection, achieving both extraction and solid-liquid separation, and therefore has good application prospects in the fields of grain storage quality testing and batch sample pretreatment. Detailed Implementation

[0021] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0022] The fatty acid value is calculated using the following formula as used in the test table: Fatty acid value = (sample standard solution volume - blank standard solution volume) × alkali concentration × 11220 × 10 ÷ 88.

[0023] The comparison difference and extraction ratio are calculated according to the following formula: Comparison difference = Average fatty acid value of reciprocating oscillation method - Average fatty acid value of vortex oscillation method; Extraction ratio = Average fatty acid value of vortex oscillation method ÷ Average fatty acid value of reciprocating oscillation method.

[0024] Example 1: Preparation of fatty acid extract from japonica rice sample QT0366 Take a well-mixed sample of japonica rice QT0366 and dehull it using a laboratory rice huller. Take 80-100 g of the dehulled sample and pulverize it using a grinder until at least 95% of the pulverized sample passes through a CQ16 sieve in one pass. Mix the pulverized sample thoroughly using a mixer or manually.

[0025] Weigh 10 g of the sample, accurate to 0.01 g, and place it in a dedicated centrifuge tube. Add 50 mL of anhydrous ethanol using a pipette or bottle-top dispenser and cap the tube. Fix the centrifuge tube horizontally on the centrifuge rack of a vortex mixer and vortex at 4000 rpm for 5 min. Then, centrifuge the tube in a dedicated centrifuge at 5000 rpm for 3 min to obtain the fatty acid extract.

[0026] When the blank standard solution volume was 0.456 mL, the sample standard solution volumes for the two parallel determinations were 1.750 mL and 1.817 mL, respectively, with fatty acid values ​​of 16.40 mg / 100 g and 17.25 mg / 100 g, respectively, and an average value of 16.83 mg / 100 g.

[0027] Comparative Example 1: Reciprocating oscillation extraction of japonica rice sample QT0366 The difference from Example 1 is that the sample was shaken for 10 minutes according to the reciprocating oscillation method of the national standard (GB / T 5510-2024), and filtered using a funnel, colorimetric tube and rapid filter paper, without using vortex oscillation and centrifugal separation.

[0028] With a blank standard solution volume of 0.456 mL, the sample standard solution volumes for two parallel determinations were 1.850 mL and 1.817 mL, respectively, with fatty acid values ​​of 17.67 mg / 100 g and 17.25 mg / 100 g, respectively, and an average value of 17.46 mg / 100 g. The difference between Example 1 and Comparative Example 1 was 0.63 mg / 100 g, and the extraction ratio was 0.96.

[0029] Example 2: Preparation of fatty acid extract from japonica rice sample QT0367 The difference from Example 1 is that the japonica rice sample number is QT0367. When the blank standard solution volume is 0.456 mL, the standard solution volume of the sample in the two parallel determinations is 1.750 mL, the fatty acid value is 16.40 mg / 100 g, and the average value is 16.40 mg / 100 g.

[0030] Comparative Example 2: Reciprocating oscillation extraction of japonica rice sample QT0367 The difference from Example 2 is that a reciprocating oscillation method was used for 10 min, and filtration was used for liquid-powder separation. With a blank standard solution volume of 0.456 mL, the sample standard solution volumes for the two parallel determinations were 1.783 mL and 1.750 mL, respectively, with fatty acid values ​​of 16.82 mg / 100 g and 16.40 mg / 100 g, respectively, and an average value of 16.61 mg / 100 g. The difference between Example 2 and Comparative Example 2 was 0.21 mg / 100 g, and the extraction ratio was 0.99.

[0031] Example 3: Preparation of fatty acid extract from japonica rice sample 23401 The difference from Example 1 is that the japonica rice sample number is 23401. When the blank standard solution volume is 0.456 mL, the standard solution volume of the sample in the two parallel determinations is 3.683 mL, the fatty acid value is 40.91 mg / 100 g, and the average value is 40.91 mg / 100 g.

[0032] Comparative Example 3: Reciprocating oscillation extraction of japonica rice sample 23401 The difference from Example 3 is that a reciprocating oscillation method was used for 10 min, and filtration was used for liquid-powder separation. With a blank standard solution volume of 0.456 mL, the standard solution volumes for the two parallel measurements were 3.650 mL and 3.617 mL, respectively, with fatty acid values ​​of 40.49 mg / 100 g and 40.07 mg / 100 g, respectively, and an average value of 40.28 mg / 100 g. The difference between Example 3 and Comparative Example 3 was -0.63 mg / 100 g, and the extraction ratio was 1.02.

[0033] The average fatty acid value of the vortex oscillation in Example 3 was higher than that in Comparative Example 3. Therefore, the difference between the two was negative and the extraction ratio was greater than 1. The reason for this result was the difference in extraction.

[0034] Example 4: Preparation of fatty acid extract from corn sample 2193 on July 1, 2026 The difference from Example 1 is that the sample is corn sample 2193, which is not hulled; and two vortex oscillation treatment times of 6 min and 10 min are set respectively.

[0035] When the blank standard solution volume was 0.456 mL, the standard solution volumes for samples treated for 6 min were 3.417 mL and 3.333 mL, respectively, with fatty acid values ​​of 37.53 mg / 100 g and 36.47 mg / 100 g, respectively, and an average of 37.00 mg / 100 g; the standard solution volumes for samples treated for 10 min were 3.583 mL and 3.500 mL, respectively, with fatty acid values ​​of 39.64 mg / 100 g and 38.59 mg / 100 g, respectively, and an average of 39.11 mg / 100 g.

[0036] Comparative Example 4: Reciprocating oscillation extraction of maize sample 2193 on July 1, 2026 The difference from Example 4 is that a reciprocating oscillation method was used for 30 min, and filtration was used for liquid-powder separation. The volumes of standard solution consumed in the two parallel determinations were 3.700 mL and 3.683 mL, respectively, and the fatty acid values ​​were 41.12 mg / 100 g and 40.91 mg / 100 g, respectively, with an average value of 41.01 mg / 100 g.

[0037] The difference between the 6-min treatment in Example 4 and Comparative Example 4 was 4.01 mg / 100 g, with an extraction ratio of 0.90; the difference between the 10-min treatment and Comparative Example 4 was 1.90 mg / 100 g, with an extraction ratio of 0.95.

[0038] Example 5: Preparation of fatty acid extract from corn sample 2029 on July 1, 2026 The difference from Example 4 is that the corn sample number was 2029. The volumes of standard solution consumed for the samples treated for 6 min were 4.317 mL and 4.217 mL, respectively, and the fatty acid values ​​were 48.94 mg / 100 g and 47.67 mg / 100 g, respectively, with an average of 48.31 mg / 100 g. The volumes of standard solution consumed for the samples treated for 10 min were 4.333 mL and 4.383 mL, respectively, and the fatty acid values ​​were 49.15 mg / 100 g and 49.78 mg / 100 g, respectively, with an average of 49.46 mg / 100 g.

[0039] Comparative Example 5: Reciprocating oscillation extraction of maize sample 2029 on July 1, 2026 The difference from Example 5 is that a reciprocating oscillation method was used for 30 min, and filtration was used for liquid-powder separation. The volume of standard solution consumed for each sample was 4.483 mL, the fatty acid value was 51.05 mg / 100 g, and the average value was 51.05 mg / 100 g.

[0040] The difference between the 6-min treatment in Example 5 and Comparative Example 5 was 2.74 mg / 100 g, with an extraction ratio of 0.95; the difference between the 10-min treatment and Comparative Example 5 was 1.58 mg / 100 g, with an extraction ratio of 0.97.

[0041] Example 6: Preparation of fatty acid extract from corn sample 2775 on July 1, 2026 The difference from Example 4 is that the corn sample number was 2775. The volumes of standard solution consumed for the samples treated for 6 min were 4.750 mL and 4.717 mL, respectively, and the fatty acid values ​​were 54.43 mg / 100 g and 54.01 mg / 100 g, respectively, with an average of 54.22 mg / 100 g. The volumes of standard solution consumed for the samples treated for 10 min were 5.033 mL and 4.983 mL, respectively, and the fatty acid values ​​were 58.02 mg / 100 g and 57.38 mg / 100 g, respectively, with an average of 57.70 mg / 100 g.

[0042] Comparative Example 6: Reciprocating oscillation extraction of maize sample 2775 on July 1, 2026 The difference from Example 6 is that a reciprocating oscillation method was used for 30 min, and filtration was used for liquid-powder separation. The volume of standard solution consumed for each sample was 5.183 mL, the fatty acid value was 59.92 mg / 100 g, and the average value was 59.92 mg / 100 g.

[0043] The difference between the 6-min treatment in Example 6 and Comparative Example 6 was 5.70 mg / 100 g, with an extraction ratio of 0.90; the difference between the 10-min treatment and Comparative Example 6 was 2.22 mg / 100 g, with an extraction ratio of 0.96.

[0044] Example 7: Preparation of fatty acid extract from corn sample 2667 on July 1, 2026 The difference from Example 4 is that the corn sample number was 2667. The volumes of standard solution consumed for the samples treated for 6 min were 6.150 mL and 6.217 mL, respectively, and the fatty acid values ​​were 72.18 mg / 100 g and 73.03 mg / 100 g, respectively, with an average of 72.60 mg / 100 g. The volumes of standard solution consumed for the samples treated for 10 min were 6.333 mL and 6.283 mL, respectively, and the fatty acid values ​​were 74.50 mg / 100 g and 73.86 mg / 100 g, respectively, with an average of 74.18 mg / 100 g.

[0045] Comparative Example 7: Reciprocating oscillation extraction of maize sample 2667 on July 1, 2026 The difference from Example 7 is that a reciprocating oscillation method was used for 30 minutes, and filtration was used for liquid-powder separation. The sample standard solution volumes were 6.650 mL and 6.667 mL, respectively, and the fatty acid values ​​were 78.52 mg / 100 g and 78.73 mg / 100 g, respectively, with an average value of 78.62 mg / 100 g, which is greater than 78 mg / 100 g, meeting the "highly unsuitable for storage" standard.

[0046] Table 1. Corn Storage Quality Indicators

[0047] The difference between the 6-min treatment in Example 7 and Comparative Example 7 was 6.02 mg / 100 g, with an extraction ratio of 0.92; the difference between the 10-min treatment and Comparative Example 7 was 4.44 mg / 100 g, with an extraction ratio of 0.94.

[0048] Example 8: Preparation of fatty acid extract from corn sample 2193 on July 3, 2026 The difference from Example 4 is that the experiment was conducted on July 3, 2026, the blank standard solution volume was 0.510 mL, and the vortex oscillation time was 8 min and 12 min, respectively.

[0049] The volumes of standard solution consumed for the samples treated for 8 min were 3.500 mL and 3.517 mL, respectively, with fatty acid values ​​of 37.90 mg / 100 g and 38.12 mg / 100 g, respectively, and an average of 38.01 mg / 100 g. The volumes of standard solution consumed for the samples treated for 12 min were 3.683 mL and 3.700 mL, respectively, with fatty acid values ​​of 40.22 mg / 100 g and 40.44 mg / 100 g, respectively, and an average of 40.33 mg / 100 g.

[0050] Comparative Example 8: Reciprocating oscillation extraction of maize sample 2193 on July 3, 2026 The difference from Example 8 is that a reciprocating oscillation method was used for 30 min, and filtration was used for liquid-powder separation. The sample standard solution volumes consumed were 3.783 mL and 3.717 mL, respectively, and the fatty acid values ​​were 41.49 mg / 100 g and 40.65 mg / 100 g, respectively, with an average value of 41.07 mg / 100 g.

[0051] The difference between the 8-min treatment in Example 8 and Comparative Example 8 was 3.06 mg / 100 g, with an extraction ratio of 0.93; the difference between the 12-min treatment and Comparative Example 8 was 0.74 mg / 100 g, with an extraction ratio of 0.98.

[0052] Example 9: Preparation of fatty acid extract from corn sample 2029 on July 3, 2026 The difference from Example 8 is that the corn sample number was 2029, and the blank standard solution volume was 0.489 mL. The standard solution volumes of the samples treated for 8 min were 4.100 mL and 4.133 mL, respectively, with fatty acid values ​​of 45.77 mg / 100 g and 46.19 mg / 100 g, respectively, and an average of 45.98 mg / 100 g; the standard solution volumes of the samples treated for 12 min were 4.233 mL and 4.300 mL, respectively, with fatty acid values ​​of 47.46 mg / 100 g and 48.31 mg / 100 g, respectively, and an average of 47.88 mg / 100 g.

[0053] Comparative Example 9: Reciprocating oscillation extraction of maize sample 2029 on July 3, 2026 The difference from Example 9 is that a reciprocating oscillation method was used for 30 min, and filtration was used for liquid-powder separation. The sample standard solution volumes were 4.367 mL and 4.400 mL, respectively, and the fatty acid values ​​were 49.16 mg / 100 g and 49.58 mg / 100 g, respectively, with an average value of 49.37 mg / 100 g.

[0054] The difference between the 8-min treatment in Example 9 and Comparative Example 9 was 3.38 mg / 100 g, with an extraction ratio of 0.93; the difference between the 12-min treatment and Comparative Example 9 was 1.48 mg / 100 g, with an extraction ratio of 0.97.

[0055] Example 10: Preparation of fatty acid extract from corn sample 2775 on July 3, 2026 The difference from Example 9 is that the corn sample number is 2775. The volumes of standard solution consumed for the samples treated for 8 min were 4.433 mL and 4.467 mL, respectively, and the fatty acid values ​​were 49.99 mg / 100 g and 50.43 mg / 100 g, respectively, with an average of 50.21 mg / 100 g; the volumes of standard solution consumed for the samples treated for 12 min were 4.617 mL and 4.633 mL, respectively, and the fatty acid values ​​were 52.33 mg / 100 g and 52.53 mg / 100 g, respectively, with an average of 52.43 mg / 100 g.

[0056] Comparative Example 10: Reciprocating oscillation extraction of maize sample 2775 on July 3, 2026 The difference from Example 10 is that a reciprocating oscillation method was used for 30 min, and filtration was used for liquid-powder separation. The sample standard solution volumes consumed were 4.783 mL and 4.717 mL, respectively, and the fatty acid values ​​were 54.43 mg / 100 g and 53.59 mg / 100 g, respectively, with an average value of 54.01 mg / 100 g.

[0057] The difference between the 8-min treatment in Example 10 and Comparative Example 10 was 3.80 mg / 100 g, with an extraction ratio of 0.93; the difference between the 12-min treatment and Comparative Example 10 was 1.58 mg / 100 g, with an extraction ratio of 0.97.

[0058] Example 11: Preparation of fatty acid extract from corn sample 2667 on July 3, 2026 The difference from Example 9 is that the corn sample number was 2667, and the blank standard solution volume was 0.510 mL. The standard solution volumes of the samples treated for 8 min were 6.333 mL and 6.350 mL, respectively, with fatty acid values ​​of 73.81 mg / 100 g and 74.03 mg / 100 g, respectively, and an average of 73.92 mg / 100 g; the standard solution volumes of the samples treated for 12 min were 6.500 mL and 6.467 mL, respectively, with fatty acid values ​​of 75.93 mg / 100 g and 75.51 mg / 100 g, respectively, and an average of 75.72 mg / 100 g.

[0059] Comparative Example 11: Reciprocating oscillation extraction of maize sample 2667 on July 3, 2026 The difference from Example 11 is that a reciprocating oscillation method was used for 30 min, and filtration was used for liquid-powder separation. The sample standard solution volumes were 6.617 mL and 6.650 mL, respectively, and the fatty acid values ​​were 77.41 mg / 100 g and 77.83 mg / 100 g, respectively, with an average value of 77.62 mg / 100 g.

[0060] The difference between the 8-min treatment in Example 11 and Comparative Example 11 was 3.70 mg / 100 g, with an extraction ratio of 0.95; the difference between the 12-min treatment and Comparative Example 11 was 1.90 mg / 100 g, with an extraction ratio of 0.98.

[0061] Example 12: Preparation of fatty acid extract from corn sample 2441 on July 6, 2026 The difference from Example 4 is that the corn sample number is 2441, the experiment date is July 6, 2026, the blank standard liquid volume is 0.500 mL, and the vortex oscillation time is 10 min and 12 min respectively.

[0062] The volumes of standard solution consumed for samples treated for 10 min were 3.513 mL and 3.517 mL, respectively, with fatty acid values ​​of 38.19 mg / 100 g and 38.24 mg / 100 g, respectively, and an average of 38.22 mg / 100 g. The volumes of standard solution consumed for samples treated for 12 min were 3.530 mL and 3.537 mL, respectively, with fatty acid values ​​of 38.41 mg / 100 g and 38.50 mg / 100 g, respectively, and an average of 38.45 mg / 100 g.

[0063] Comparative Example 12: Reciprocating oscillation extraction of maize sample 2441 on July 6, 2026 The difference from Example 12 is that a reciprocating oscillation method was used for 30 min, and filtration was used for liquid-powder separation. The sample standard solution volumes were 3.637 mL and 3.683 mL, respectively, and the fatty acid values ​​were 39.76 mg / 100 g and 40.35 mg / 100 g, respectively, with an average value of 40.06 mg / 100 g.

[0064] The difference between the 10-min treatment in Example 12 and Comparative Example 12 was 1.84 mg / 100 g, with an extraction ratio of 0.95; the difference between the 12-min treatment and Comparative Example 12 was 1.60 mg / 100 g, with an extraction ratio of 0.96.

[0065] Example 13: Preparation of fatty acid extract from corn sample 2725 on July 6, 2026 The difference from Example 12 is that the corn sample number was 2725. The volumes of standard solution consumed for the samples treated for 10 min were 5.487 mL and 5.513 mL, respectively, and the fatty acid values ​​were 63.22 mg / 100 g and 63.55 mg / 100 g, respectively, with an average of 63.38 mg / 100 g. The volumes of standard solution consumed for the samples treated for 12 min were 5.562 mL and 5.528 mL, respectively, and the fatty acid values ​​were 64.17 mg / 100 g and 63.74 mg / 100 g, respectively, with an average of 63.95 mg / 100 g.

[0066] Comparative Example 13: Reciprocating oscillation extraction of maize sample 2725 on July 6, 2026 The difference from Example 13 is that a reciprocating oscillation method was used for 30 min, and filtration was used for liquid-powder separation. The sample standard solution volumes were 5.712 mL and 5.695 mL, respectively, and the fatty acid values ​​were 66.07 mg / 100 g and 65.85 mg / 100 g, respectively, with an average value of 65.96 mg / 100 g.

[0067] The difference between the 10-min treatment in Example 13 and Comparative Example 13 was 2.58 mg / 100 g, with an extraction ratio of 0.96; the difference between the 12-min treatment and Comparative Example 13 was 2.01 mg / 100 g, with an extraction ratio of 0.97.

[0068] Example 14: Preparation of fatty acid extract from corn sample 2418 on July 6, 2026 The difference from Example 12 is that the corn sample number was 2418. The volumes of standard solution consumed for the samples treated for 10 min were 3.482 mL and 3.487 mL, respectively, and the fatty acid values ​​were 37.80 mg / 100 g and 37.86 mg / 100 g, respectively, with an average of 37.83 mg / 100 g. The volumes of standard solution consumed for the samples treated for 12 min were 3.590 mL and 3.613 mL, respectively, and the fatty acid values ​​were 39.17 mg / 100 g and 39.46 mg / 100 g, respectively, with an average of 39.31 mg / 100 g.

[0069] Comparative Example 14: Reciprocating oscillation extraction of maize sample 2418 on July 6, 2026 The difference from Example 14 is that a reciprocating oscillation method was used for 30 min, and filtration was used for liquid-powder separation. The sample standard solution volumes were 3.687 mL and 3.643 mL, respectively, and the fatty acid values ​​were 40.40 mg / 100 g and 39.84 mg / 100 g, respectively, with an average value of 40.12 mg / 100 g.

[0070] The difference between the 10-min treatment in Example 14 and Comparative Example 14 was 2.29 mg / 100 g, with an extraction ratio of 0.94; the difference between the 12-min treatment and Comparative Example 14 was 0.80 mg / 100 g, with an extraction ratio of 0.98.

[0071] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A method for preparing a fatty acid extract from rice or corn, characterized in that, Includes the following steps: The rice sample was dehulled, while the corn sample was not dehulled. The rice or corn sample was crushed and mixed thoroughly. The resulting sample was placed in a centrifuge tube and anhydrous ethanol was added. The capped centrifuge tube was placed on the centrifuge rack of a vortex mixer and vortexed at a speed of 4000 rpm. The vortexing was performed for 3-5 minutes for the rice sample and 5-8 minutes for the corn sample. The vortexed centrifuge tube was then centrifuged in a centrifuge with a maximum speed of 5000 rpm for 3 minutes to obtain the fatty acid extract.

2. The preparation method according to claim 1, characterized in that, The mass ratio of the rice or corn sample to the volume of anhydrous ethanol is 1 g: 5 mL.

3. The preparation method according to claim 1, characterized in that, The proportion of pulverized samples that pass through the CQ16 sieve in one pass is over 95%.

4. The preparation method according to claim 1, characterized in that, The centrifuge tubes are fixed to the centrifuge rack in a horizontal arrangement.

5. A fatty acid extract of rice or corn prepared by the method according to any one of claims 1 to 4.

6. The application of the fatty acid extract according to claim 5 in the determination of fatty acid value of rice or corn.

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