Method for identifying specificity of red seed coat peanuts based on high antioxidant active substances

Abstract

The invention discloses a method for identifying the specificity of red seed coat peanuts based on high antioxidant active substances, which is used for identifying or identifying peeled peanut materials or other industrial and agricultural peanut materials, and constructs a specific chromatographic analysis path based on newly found specific chemical components in the red seed coat peanuts. And the red seed coat peanut raw material is identified and identified based on the specific characteristic chromatographic peak of the red seed coat peanut material. For common peanut protein powder, peeled peanut powder, peeled peanut seed kernels and other common materials, the method can directly identify whether the agricultural and industrial peanut raw materials are red-seed-coat peanut sources or not without depending on the integrity of seed coats, and an important technical basis is provided for quality control and variety identification of the peanut raw materials.

Description

[0001] This application is a divisional application of the following patent application: Invention title: A specific identification method and new use of red-coated peanut raw materials; Application number: 202410827655.X; Application date: 2024-06-25. Technical Field

[0002] This invention relates to the field of chromatographic analysis technology, and in particular to a specific identification method for red-coated peanut raw materials and its subsequent expansion technologies and application development. Background Technology

[0003] Peanuts are an important oilseed and cash crop, and a significant source of various functional nutrients. While the red skin of peanuts is rich in functional components and has medicinal value, it is typically removed during the processing of peanut oil and peanut products, making it difficult for its chemical components to exert their effects in peanut-related products. Conversely, the functional components in peanut kernels without the red skin coexist with the crude fat, crude protein, and other nutrients in the kernel, making them easier for humans to absorb. This plays a more positive role in meeting the high-quality nutritional needs of humans and the healthy development of the peanut industry. However, there are significant differences in the functional components of peeled peanut kernels among peanut varieties with different skin colors.

[0004] Currently, cultivated peanut seed coat colors include pink, red, dark purple, and white. Our research group has discovered a series of unique chemical components in red-coated peanut kernels, which possess extremely high antioxidant activity. Based on these findings, we have further developed a method for identifying the source of peeled peanut kernels or powder, which has significant practical implications. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a specific method for identifying red seed coat peanuts based on highly antioxidant active substances, thereby filling the gap in the existing technology.

[0006] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows.

[0007] This invention includes a novel use of quercetin-3-O-rutin-7-O-xylose / arabinoside for the specific identification of red-coated peanuts.

[0008] The present invention also includes novel uses for quercetin-3-O-rutin-7-O-xylose / arabinoside as a highly antioxidant active substance in the food, pharmaceutical, cosmetic and chemical industries.

[0009] The present invention also includes a method for identifying red-skinned peanut raw materials without relying on the integrity of the seed coat, for the identification or identification of peeled peanut materials or other industrial and agricultural peanut materials. Based on newly discovered unique chemical components in red-skinned peanuts, a specific chromatographic analysis path is constructed, and the identification and identification of red-skinned peanut raw materials are based on the characteristic chromatographic peaks unique to red-skinned peanut materials.

[0010] As a preferred technical solution of the present invention, the method is adapted to at least the following peanut raw materials: peanut protein powder, peeled peanut powder, and peeled peanut kernels.

[0011] As a preferred embodiment of the present invention, the unique chemical component is a single component or multiple components with extremely high antioxidant activity.

[0012] As a preferred embodiment of the present invention, the unique chemical components include, but are not limited to: quercetin-3-O-rutin-7-O-xylose / arabinoside.

[0013] As a preferred embodiment of the present invention, the specific chromatographic analysis path specifically includes the following implementation steps:

[0014] A. Material processing; For peanut protein powder and peeled peanut powder, the material can be directly obtained; For peeled peanut kernels, the peanut material to be tested is naturally air-dried to a moisture content of less than 5%, and mature, plump, undamaged and unmolded peanut kernels are selected, ground with a grinder, and passed through a 20-mesh sieve to obtain the sample powder to be tested.

[0015] B. Preparation of extract: Accurately weigh 0.1 g of the sample powder to be tested and place it in a 2 mL centrifuge tube. After defatting twice with n-hexane, accurately add 50% methanol aqueous solution (V / V) at a ratio of 1 g: 15 mL (m / V), mix well, soak for 30 min, and then extract with ultrasonic assistance at room temperature, 250 W, 40 kHz, for 30 min, shaking once every 10 min during the process; centrifuge at room temperature and accurately measure the supernatant to obtain the primary extract;

[0016] C. Characteristic transformation treatment: Take 1,1-diphenyl-2-trinitrophenylhydrazine (DPPH), add methanol precisely at a ratio of 12.7 mL per 1 mg DPPH to prepare a 200 μmol / L DPPH methanol solution, dissolve with ultrasonic assistance for 1 min at 250 W and 40 kHz, mix thoroughly, and filter using a 0.2 μm microporous membrane to obtain the characteristic extract.

[0017] D. Feature comparison processing: Mix the primary extract with twice the volume of methanol and let stand for 60 min to prepare the first-stage extract; mix the primary extract with 200 μmol / L feature extract and react in the dark for 60 min to prepare the second-stage extract;

[0018] E. Chromatographic Analysis; The chemical components in the extract were analyzed using an ultra-high performance liquid chromatography (UHPLC) system. Chromatographic conditions were as follows: Agilent ZORBAX SB-C18 column, 2.1 × 100 mm, 1.8 μm; column temperature 35℃; mobile phase: Phase A was 0.2% (v / v) formic acid aqueous solution, Phase B was acetonitrile, flow rate 0.35 mL / min; injection volume 2.0 μL; detection wavelength 354 nm; elution program: 0–0.5 min, 10% B; 0.5–1 min, 10%–15% B; 1.0–2.5 min, 11% B; 2.5–9.5 min, 11%–25% B; 9.5–11.0 min, 25% B; 11.0–13.5 min, 25%–40% B; 13.5–15.0 min, 40%–95% B; 15.0–22.0 min, 10% B. B;

[0019] F. Dual Characteristic Analysis; Identification and characterization of red-skinned peanuts based on dual characteristic analysis of chromatograms; the dual analysis includes: first, whether the primary extract has characteristic chromatographic peaks at specific node intervals or sites on the chromatogram; second, whether the primary extract and the secondary extract have characteristic peak differences at specific node intervals or sites on the chromatogram; the test material that passes both the first and second tests can be confirmed as red-skinned peanuts.

[0020] As a preferred embodiment of the present invention, the specific node interval is the node interval of 6 to 7.5 min on the chromatogram;

[0021] As a preferred embodiment of the present invention, the specific node interval is the node interval of 6.5~7 min on the chromatogram;

[0022] As a preferred embodiment of the present invention, the specific node interval is a smaller interval around 6.7 min on the chromatogram.

[0023] A method for identifying red-skinned peanut materials from common peanut populations, for peanut protein powder, peeled peanut powder, and peeled peanut kernels, using the method described in any one of claims 1-8 to identify and distinguish red-skinned peanuts; the common peanut populations include, but are not limited to: Jihua 5211, Tailai Silihong, Fushan Hongdou peanut, Nenjiang Silihong, Beida Yiwohou, Jihua 16, Jihua 13, Jihua 21, Jihua 19, Jihua 18, Juhuang 1, Heizhenzhu 2, Zhonghua 9, Jihua Hei 3, Heixiaoniu, Y21326 peanut, Y21202 peanut, Y21201 peanut, 21-61169 peanut, 21-zw072 peanut, and Jihua Tian 1.

[0024] New uses for red-skinned peanuts include: as a source of highly active antioxidants; or as a food ingredient with higher antioxidant activity compared to non-red-skinned peanuts; or, compared to non-red-skinned peanuts, reducing the need for artificial antioxidants and extending the shelf life of peanut products, thereby further promoting the positive health benefits of the entire peanut industry chain.

[0025] The beneficial effects of adopting the above technical solution are as follows: For common materials such as peanut protein powder, peeled peanut powder, and peeled peanut kernels, this invention can directly identify whether these agricultural and industrial peanut raw materials are from red-shelled peanuts without relying on the integrity of the seed coat, providing an important technical foundation for the quality control and variety identification of peanut raw materials. Furthermore, the discovery of the unique high antioxidant active ingredients in red-shelled peanut kernels can extend the shelf life of peanut products and reduce the artificial addition of antioxidants, which has a positive effect on the healthy development of the entire peanut industry chain.

[0026] Specifically, the technical advantages of this invention include at least the following: ① It does not depend on the integrity of the seed coat; the method of this invention can effectively identify peeled peanut materials, peanut protein powder, peeled peanut powder, etc.; ② Sample processing is simple, with direct sampling or simple processing such as air drying, grinding, and sieving, resulting in high operational efficiency; ③ Low equipment requirements, using an ultra-high performance liquid chromatography system for analysis, which is lower in cost and easier to operate compared to other expensive equipment, making it suitable for various laboratories and enterprises; ④ High specificity and sensitivity, based on the unique chemical components in red-skinned peanuts, a specific chromatographic analysis pathway is constructed, and dual characteristic analysis ensures high specificity and sensitivity of the identification.

[0027] It is worth noting that the core technical elements and effects of this invention are as follows: through feature transformation and feature comparison processing, specific characteristic chromatographic peaks and characteristic chromatographic peak gaps are displayed on the chromatogram, which can accurately identify and characterize red seed coat peanut raw materials. Attached Figure Description

[0028] Figure 1This is a typical chromatogram of peanut kernel extract with the red skin removed; in the figure: red-skinned peanut (A), pink-skinned peanut (B), black-purple-skinned peanut (C), and white-skinned peanut (D).

[0029] Figure 2 Typical chromatograms of peanut kernel extract with red seed coat removed before (A) and after (B) reaction with DPPH.

[0030] Figure 3 This is a primary mass spectrum of the characteristic chromatographic peaks of red-coated peanut kernels.

[0031] Figure 4 This is a schematic diagram of the secondary mass spectrometry information of the characteristic chromatographic peaks of red-coated peanut kernels.

[0032] Figure 5 This is a schematic diagram illustrating the hypothetical fragmentation pattern of quercetin in positive ion mode. Detailed Implementation

[0033] The following embodiments illustrate the present invention in detail. All raw materials and equipment used in the present invention are conventional commercially available products and can be directly obtained through market purchase. It should be understood that, when used in this specification and appended claims, the term "comprising" indicates the presence of the described features, integrals, steps, operations, elements, and / or components, but does not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components, and / or collections thereof. It should also be understood that the term "and / or" as used in this specification and appended claims refers to any combination and all possible combinations of one or more of the associated listed items, and includes such combinations. As used in this specification and appended claims, the term "if" can be interpreted, depending on the context, as "when," "once," "in response to determination," or "in response to detection." Similarly, the phrase "if determined" or "if detected [the described condition or event]" can be interpreted, depending on the context, as meaning "once determined," "in response to determination," "once detected [the described condition or event]," or "in response to detection [the described condition or event]."

[0034] Furthermore, in the description of this application and the appended claims, the terms "first," "second," "third," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance. References to "one embodiment" or "some embodiments" in this application mean that one or more embodiments of this application include a specific feature, structure, or characteristic described in connection with that embodiment. Therefore, the phrases "in one embodiment," "in some embodiments," "in other embodiments," "in still other embodiments," etc., appearing in different parts of this specification do not necessarily refer to the same embodiment, but rather mean "one or more, but not all, embodiments," unless otherwise specifically emphasized. The terms "comprising," "including," "having," and variations thereof mean "including but not limited to," unless otherwise specifically emphasized.

[0035] Example 1: Overview of Identification Methods

[0036] This invention is used for the identification or characterization of peeled peanut materials or other peanut materials used in industry and agriculture. Based on newly discovered unique chemical components in red-shelled peanuts, a specific chromatographic analysis pathway is constructed, and the identification and characterization of red-shelled peanut raw materials are based on the characteristic chromatographic peaks unique to red-shelled peanut materials. The method is suitable for at least the following peanut raw materials: peanut protein powder, peeled peanut powder, and peeled peanut kernels.

[0037] Specifically, considering industrial applications, this invention can at least identify red-coated peanut materials from common peanut populations, including but not limited to: Jihua 5211, Tailai Silihong, Fushan Hongdou peanut, Nenjiang Silihong, Beida Yiwohou, Jihua 16, Jihua 13, Jihua 21, Jihua 19, Jihua 18, Juhuang 1, Heizhenzhu 2, Zhonghua 9, Jihua Hei 3, Heixiaoniu, Y21326 peanut, Y21202 peanut, Y21201 peanut, 21-61169 peanut, 21-zw072 peanut, and Jihua Tian 1.

[0038] Example 2, Application Overview

[0039] Through further in-depth research, this invention has confirmed that red-coated peanuts contain a variety of highly active antioxidants, and has further preliminarily identified candidate dominant antioxidant compounds: quercetin-3-O-rutin-7-O-xylose / arabinoside.

[0040] For new uses of red-skinned peanuts, consider their potential as a source of highly active antioxidants; or, as a food ingredient with higher antioxidant activity compared to non-red-skinned peanuts; or, compared to non-red-skinned peanuts, reduce the artificial addition of antioxidants and extend the shelf life of peanut products, further promoting the positive health benefits of the entire peanut industry chain.

[0041] Example 3, Materials and Methods

[0042] 1.1 Experimental Materials

[0043] This study used 21 different peanut varieties provided by the Grain and Oil Crops Research Institute of the Hebei Academy of Agricultural and Forestry Sciences. Twenty varieties (numbered S01-S20) were used to compare the differences in chemical composition of peanut kernels after the red skin was removed, as detailed in Table 1. Five varieties each had red, pink, dark purple, and white seed coats. Variety S21, Jihua Tian 1, with a red seed coat, was used for characterization and structural identification of its antioxidant active ingredients. All peanut materials were naturally air-dried to a moisture content below 5%. Mature, plump, and undamaged peanut seeds were selected, the seed coats were removed, and the kernels were ground using a grinder and passed through a 20-mesh sieve to obtain the peanut kernel powder sample after the red skin was removed.

[0044] Table 1. Overview of Peanut Variety Information

[0045]

[0046] 1.2 Preparation of peanut kernel extract (with skin removed)

[0047] Accurately weigh approximately 0.1 g of peanut kernel powder (without red skin) and place it in a 2 mL centrifuge tube. Defatt the powder twice with n-hexane. Then, precisely add 50% methanol aqueous solution (V / V) at a ratio of 1 g:15 mL (m / V), mix well, and soak for 30 min. Extract using ultrasonic-assisted extraction at room temperature (250 W, 40 kHz) for 30 min, shaking every 10 min. Centrifuge at room temperature and accurately measure the supernatant to obtain the peanut kernel extract (without red skin).

[0048] 1.3 Characterization of antioxidant active ingredients I

[0049] Take an appropriate amount of 1,1-diphenyl-2-trinitrophenylhydrazine (DPPH), accurately weigh it, and add an appropriate amount of methanol at a ratio of 12.7 mL per 1 mg DPPH to prepare a 200 μmol / L DPPH methanol solution. Dissolve it with ultrasonic assistance for 1 min (250 W, 40 kHz), mix thoroughly, and filter it using a 0.2 μm microporous membrane for later use.

[0050] 1.4 Characterization of Antioxidant Active Ingredients II

[0051] The peanut kernel extract with red seed coat removed was mixed with twice its volume of methanol and allowed to stand for 60 min to prepare the peanut kernel extract before DPPH reaction. The peanut kernel extract with red seed coat removed was mixed with 200 μmol / L DPPH methanol solution and reacted in the dark for 60 min to prepare the peanut kernel extract with red seed coat removed after DPPH reaction.

[0052] 1.5 Chromatographic Analysis

[0053] The chemical components in the extract of peanut kernels with the red skin removed were analyzed using the Acquity UPLC H-Class ultra-high performance liquid chromatography system. The chromatographic conditions were as follows: Agilent ZORBAX SB-C18 column (2.1 × 100 mm, 1.8 μm); column temperature 35℃; mobile phase: phase A was 0.2% (v / v) formic acid aqueous solution, phase B was acetonitrile, flow rate 0.35 mL / min; injection volume 2.0 μL; detection wavelength 354 nm; elution program: 0–0.5 min, 10% B; 0.5–1 min, 10%–15% B; 1.0–2.5 min, 11% B; 2.5–9.5 min, 11%–25% B; 9.5–11.0 min, 25% B; 11.0–13.5 min, 25%–40% B; 13.5–15.0 min, 40%–95% B; 15.0–22.0 min, 10% B.

[0054] 1.6 Structural Identification of Antioxidant Active Ingredients

[0055] Using optimized chromatographic conditions, the structure of antioxidant active substances in peanut kernels (without red skin) was further analyzed using an Acquity TRIPLE TOF 5600 liquid chromatography-mass spectrometry system. Electrospray ionization (ESI) was used as the ion source, employing both positive and negative ion scanning modes. In negative ion mode, the ion spray voltage was 4500 V, the nebulizing gas flow rate was 50 L / min, the auxiliary gas flow rate was 55 L / min, the curtain gas flow rate was 30 L / min, and the collision energy was set to 35 V. In positive ion mode, the scan range was set to 100–1200 Da, the ion spray voltage was 5500 V, the nebulizing gas flow rate was 50 L / min, the auxiliary gas flow rate was 55 L / min, the curtain gas flow rate was 30 L / min, and the collision energies were set to 15 V, 35 V, and 90 V, respectively.

[0056] Example 4, Experimental Results

[0057] 1.1 Differences in Chemical Composition of Peanuts with Different Skin Colors (Red Skin Removed)

[0058] Typical chromatograms of peanut kernel extracts (without red skin) from red-skinned peanuts (A), pink-skinned peanuts (B), black-purple-skinned peanuts (C), and white-skinned peanuts (D) under the chromatographic analysis conditions used in this study are shown below. Figure 1 As shown, at 354 nm, the chemical substances in peanut kernels with red seed coats and removed red skins were significantly more abundant than those in peanut kernels with other seed coat colors. Furthermore, at a retention time of approximately 6.7 min, a characteristic chromatographic peak was observed only in peanut kernels with red seed coats. This indicates a correlation between the chemical components in peanut kernels and seed coat color, making it technically feasible to identify peanuts with red seed coats using the characteristic chromatographic peaks of peanut kernels with removed seed coats.

[0059] 1.2 Characterization of antioxidant active components in peanut kernels with red skin removed

[0060] Typical chromatograms of peanut kernel extract with red seed coat removed (A) and (B) before and after reaction with DPPH, as shown in Figure 1. Figure 2 As shown in the figure. Comparison revealed that after reaction with DPPH methanol solution, several chromatographic peaks in the extract of red-skinned peanut kernels completely disappeared or their peak heights significantly decreased, indicating that the chemical components represented by these peaks possess DPPH free radical reactivity, i.e., antioxidant activity. The chemical component represented by the chromatographic peak with a retention time of approximately 6.7 min is not only unique to red-skinned peanut kernels but also exhibits higher antioxidant activity than other chemical components in peanut kernels.

[0061] 1.3 Structural identification of antioxidant active components in red-coated peanut kernels

[0062] The characteristic chromatographic peaks of red-coated peanut kernels in primary mass spectra under negative (A) and positive (B) ion modes, as shown in... Figure 3 As shown, a mass number peak of m / z 741.1874 is observed in negative ion mode, and a mass number peak of m / z 743.2032 is observed in positive ion mode. Based on this, it can be inferred that the molecular ion peak [MH] of this compound... - The peak is at m / z 741.1874, and the molecular ion peak is [M+H]. + The peak value is 743.2032 m / z.

[0063] In positive ion mode, for [M+H] + The secondary mass spectrum obtained by scanning the peaks for daughter ions, such as... Figure 4As shown in B~D. When the collision energy is 35V, a fragment peak with a mass number of m / z 303.0490 can be observed. When the collision energy increases to 90V, the fragment peak with a mass number of m / z 303.0490 further fragments to produce fragment peaks with mass numbers of m / z 285.0401, m / z 275.0559, m / z 257.0440, and m / z 229.0494, which is consistent with the fragmentation pattern of quercetin in positive ion mode. Figure 5 As shown. Therefore, it can be inferred that the characteristic chromatographic peaks of the red-coated peanut kernel represent flavonoids with quercetin as the aglycone. In negative ion mode, [MH] - The secondary mass spectrum obtained by scanning the peaks for daughter ions, such as... Figure 4 As shown in Figure A, a fragment peak with mass number m / z 300.0275 can be observed, with a neutral loss of 441, consistent with the neutral loss pattern of rhamnose (146), glucosyl or galactosyl (162), and xylose or arabinose (132). It is speculated that the fragment with mass number m / z 300.0275 is [MH-132-146-162]. - Peaks. In positive ion mode, at a collision energy of 15V, fragment peaks with mass numbers m / z 611.1593, m / z 465.1029, m / z 303.0505, m / z 597.1447, and m / z 449.1054 can be observed, which are presumed to be [M+H-132]. + Peak, [M+H-132-146] + Peak, [M+H-132-146-162] + Peak, [M+H-146] + Peak, [M+H-132-162] + Peak. [M+H-162] was not observed. + The peak suggests that glucose or galactose (180) is not directly linked to quercetin aglycone, but rather forms a disaccharide with rhamnose (164), xylose, or arabinose (150) before being linked to quercetin aglycone. Based on relevant literature reports, the compound represented by the characteristic chromatographic peak in the red peanut seed coat is presumed to be quercetin-3-O-rutin-7-O-xylose / arabinoside.

[0064] In the above embodiments, the descriptions of each embodiment have their own emphasis. Parts not described in detail in a certain embodiment can be referred to in the relevant descriptions of other embodiments. The above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be included within the protection scope of the present invention.

Claims

1. A novel use of quercetin-3-O-rutin-7-O-xylose / arabinoside, characterized by: Specific identification for red-coated peanuts.

2. A novel application of quercetin-3-O-rutin-7-O-xylose / arabinoside, characterized by: It is used as a highly antioxidant substance in the food, pharmaceutical, cosmetic, and chemical industries.

3. A method for identifying red-coated peanut raw materials without relying on seed coat integrity, used for the identification or characterization of peeled peanut materials or other industrial and agricultural peanut materials, characterized in that: Based on the newly discovered unique chemical components in red-skin peanuts, a specific chromatographic analysis pathway was constructed, and the raw materials of red-skin peanuts were identified and characterized based on the unique chromatographic peaks of the red-skin peanut material; the unique chemical components are single or multiple components with extremely high antioxidant activity.

4. The method for identifying red-coated peanut raw materials without relying on seed coat integrity according to claim 3, characterized in that: The unique chemical components include, but are not limited to: quercetin-3-O-rutin-7-O-xylose / arabinoside.

5. The method for identifying red-coated peanut raw materials without relying on seed coat integrity according to claim 4, characterized in that: The specific chromatographic analysis path includes the following implementation steps: A. Material processing; For peanut protein powder and peeled peanut powder, the material can be directly obtained; For peeled peanut kernels, the peanut material to be tested is naturally air-dried to a moisture content of less than 5%, and mature, plump, undamaged and unmolded peanut kernels are selected, ground with a grinder, and passed through a 20-mesh sieve to obtain the sample powder to be tested. B. Preparation of extract: Accurately weigh 0.1 g of the sample powder to be tested and place it in a 2 mL centrifuge tube. After defatting twice with n-hexane, accurately add 50% methanol aqueous solution (V / V) at a ratio of 1 g: 15 mL (m / V), mix well, soak for 30 min, and then extract with ultrasonic assistance at room temperature (250 W, 40 kHz, 30 min, shaking once every 10 min). Centrifuge at room temperature and accurately measure the supernatant to obtain the primary extract. C. Characteristic transformation treatment: Take 1,1-diphenyl-2-trinitrophenylhydrazine (DPPH), add methanol precisely at a ratio of 12.7 mL per 1 mg DPPH to prepare a 200 μmol / L DPPH methanol solution, dissolve with ultrasonic assistance for 1 min at 250 W and 40 kHz, mix thoroughly, and filter using a 0.2 μm microporous membrane to obtain the characteristic extract. D. Feature comparison processing: Mix the primary extract with twice the volume of methanol and let stand for 60 min to prepare the first-stage extract; mix the primary extract with 200 μmol / L feature extract and react in the dark for 60 min to prepare the second-stage extract; E. Chromatographic analysis; analysis of chemical components in the extract was performed using an ultra-high performance liquid chromatography system; chromatographic conditions were: Agilent ZORBAX SB-C18 column, 2.1 × 100 mm, 1.8 μm; column temperature 35℃; Mobile phase: Phase A is 0.2% (v / v) formic acid aqueous solution, Phase B is acetonitrile, flow rate is 0.35 mL / min; injection volume is 2.0 μL; detection wavelength is 354 nm; elution program: 0–0.5 min, 10% B; 0.5–1 min, 10%–15% B; 1.0~2.5 min, 11% B; 2.5~9.5 min, 11%~25% B; 9.5~11.0 min, 25% B; 11.0~13.5 min, 25%~40% B; 13.5~15.0 min, 40%~95% B; 15.0–22.0 min, 10% B; F. Dual Feature Analysis; Identification and characterization of red-coated peanuts based on dual feature analysis of chromatograms; the dual analysis includes: first, whether the primary extract has characteristic chromatographic peaks at specific node intervals or node sites on the chromatogram; The second step: On the chromatogram, whether the primary extract and the secondary extract have characteristic chromatographic peak differences at specific node intervals or specific node sites; at the same time, the test material that passes the first and second steps of testing can be confirmed as red-skinned peanut.

6. The method for identifying red-coated peanut raw materials without relying on seed coat integrity according to claim 5, characterized in that: The specific node interval is the 6-7.5 min interval on the chromatogram.

7. The method for identifying red-coated peanut raw materials without relying on seed coat integrity according to claim 5, characterized in that: The specific node interval is the 6.5-7 min interval on the chromatogram.

8. The method for identifying red-coated peanut raw materials without relying on seed coat integrity according to claim 5, characterized in that: The specific node interval is a smaller interval around 6.7 min on the chromatogram.

9. A method for identifying red-coated peanut materials from common peanut populations, characterized in that: For peanut protein powder, peeled peanut powder, and peeled peanut kernels, the method described in any one of claims 3-8 shall be used for identification to identify and distinguish red-skinned peanuts; the common peanut groups include, but are not limited to: Jihua 5211, Tailai Silihong, Fushan Hongdou peanut, Nenjiang Silihong, Beida Yiwohou, Jihua 16, Jihua 13, Jihua 21, Jihua 19, Jihua 18, Juhuang 1, Heizhenzhu 2, Zhonghua 9, Jihua Hei 3, Heixiaoniu, Y21326 peanut, Y21202 peanut, Y21201 peanut, 21-61169 peanut, 21-zw072 peanut, and Jihua Tian 1.

10. A new use for red-coated peanuts, characterized by: Used as a source of highly active antioxidants; or, as a food ingredient with higher antioxidant activity compared to non-red-skinned peanuts. Alternatively, reduce the artificial addition of antioxidants compared to non-red-skinned peanuts and extend the shelf life of peanut products.

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