Method for preparing peanut skin extract and application thereof

Abstract

The invention relates to a method for preparing a peanut membrane extract by taking peanut membranes as raw materials, the peanut membrane extract obtained by the method and application of the peanut membrane extract in compositions (such as functional foods, health-care products or nutritional supplements). According to the preparation method of the peanut membrane extract provided by the invention, the peanut membrane extract with high content of total polyphenol and proanthocyanidin (OPC) and excellent alpha-amylase inhibitory activity can be efficiently and stably prepared by optimizing a combined process of raw material treatment, extraction, concentration and sterilization treatment. The extract has definite development and application values in the aspects of blood sugar regulation, oxidation resistance and the like.

Description

(19) State Intellectual Property Office (12) Invention Patent Application (10) Application Publication Number (43) Application Publication Date (21) Application Number 202610031249.1 (22) Application Date 2026.01.09 (71) Applicant: Dajiang Biotechnology (Shanghai) Co., Ltd. Address: No. 989, Jinge Road, Jinshan Industrial Zone, Jinshan District, Shanghai 201506 (72) Inventors: Lin Yongxiang, Tian Zhong'an, Lin Huanyou, Yang Yishan, Yang Peilin (74) Patent Agency: Shanghai Huacheng Intellectual Property Agency Co., Ltd. 31300 Patent Attorney: Du Juan (51) Int.Cl. A23L 33 / 105 (2016.01) (54) Invention Title: Method for preparing peanut membrane extract and its application (57) Abstract: This disclosure relates to a method for preparing peanut membrane extract from peanut membrane as raw material, and the peanut membrane extract obtained by the method and its application in compositions (such as functional foods, health products or nutritional supplements). The peanut membrane extract preparation method disclosed herein, through optimized combination of raw material processing, extraction, concentration, and sterilization, can efficiently and stably prepare a peanut membrane extract with high total polyphenol and proanthocyanidin (OPC) content and excellent α-amylase inhibitory activity. This extract has clear development and application value in regulating blood sugar and antioxidation. Claims 1 page, Description 9 pages, Drawings 2 pages CN 121533529 A 2026.02.17 CN 1 21 53 35 29 A 1. A method for preparing peanut membrane extract, characterized in that the method includes the following steps: (1) Raw material treatment: drying and crushing the peanut membrane obtained after shelling peanuts to obtain peanut membrane raw material; (2) Water extraction: mixing the peanut membrane raw material with water at a material-to-water ratio of 1:10 to 1:30, and extracting at a temperature of 60 to 90°C for 30 to 60 min to obtain peanut membrane initial extract; (3) Filtration and concentration: filtering the peanut membrane initial extract to obtain peanut membrane filtrate; concentrating the peanut membrane filtrate by a concentration factor of 10 to 20 times to obtain peanut membrane concentrate; (4) Sterilization treatment: heat sterilizing the peanut membrane concentrate at a temperature of 80 to 100°C for 60 to 90 min to obtain peanut membrane extract. 2. The method according to claim 1, wherein in step (2), the water is reverse osmosis water and / or deionized water. 3. The method according to claim 1, wherein the soluble solids content of the initial peanut membrane extract at 20°C is greater than 0.8 Brix. 4. The method according to claim 1, wherein in step (3), the concentration is vacuum concentration; and / or step (3) further includes secondary filtration of the peanut membrane concentrate.5. The method according to claim 1, wherein the soluble solids content of the peanut membrane concentrate at 20°C is 18-20 Brix. 6. The method according to claim 1, wherein in step (4), the sterilization temperature is 85-95°C and the sterilization time is 60-80 min. 7. The method according to any one of claims 1 to 6, further comprising step (5): (5) Drying treatment: drying the peanut membrane extract obtained in step (4) to obtain a peanut membrane extract in powder form. 8. The method according to claim 7, wherein the drying treatment is spray drying, and / or sieving the obtained peanut membrane extract in powder form. 9. A peanut membrane extract, wherein the peanut membrane extract is prepared by the method according to any one of claims 1 to 8, and the peanut membrane extract is in liquid or powder form. 10. The peanut membrane extract according to claim 9, wherein the total polyphenol content in the peanut membrane extract is 20-40 g / 100 g. 11. The peanut membrane extract according to claim 9 or 10, characterized in that the proanthocyanidin content in the peanut membrane extract is 65-85 wt%. 12. The peanut membrane extract according to any one of claims 9 to 11, characterized in that the α-amylase inhibition rate of the peanut membrane extract at 0.2 mg / mL, 0.25 v / v % or equivalent concentration is 30% or more. 13. The use of the peanut membrane extract according to any one of claims 9 to 12 in the preparation of compositions for regulating blood sugar and / or antioxidation. 14. The use according to claim 13, wherein the composition is used to inhibit α-amylase activity. Claims 1 / 1 page 2 CN 121533529 A Method for preparing peanut membrane extract and its application technical field

[0001] This disclosure relates to a method for preparing peanut membrane extract from peanut membrane as raw material, and the peanut membrane extract obtained by the method and its application in compositions (such as functional foods, health products or nutritional supplements). Background Art

[0002] Peanut (Arachis hypogaea) is an important oilseed and economic crop widely cultivated worldwide. Peanut membrane (also known as peanut skin or peanut fruit membrane) is a byproduct of peanut processing and has long been treated as a low-value raw material or even discarded. However, research shows that peanut membrane is rich in polyphenols, proanthocyanidins (OPC), and other natural active ingredients, which have potential physiological functions such as anti-oxidation and regulation of sugar metabolism.

[0003] In the prior art, the extraction methods for active ingredients in peanut membrane often suffer from problems such as low extraction efficiency, low content of active ingredients (such as polyphenols and OPC), complex processes, or imprecise condition control.Furthermore, how to optimize the process parameters of unit operations such as extraction, concentration, and filtration to maximize the retention of its bioactivity directly related to blood sugar reduction, such as inhibiting α-amylase, while ensuring high OPC content, is an important problem that current technology needs to solve.

[0004] Therefore, developing a method for obtaining peanut membrane extract with simple process, controllable conditions, and stable polyphenol and OPC content and significant α-amylase inhibitory activity has important industrial value. Summary of the Invention

[0005] In view of the above-mentioned problems and needs in the art, this disclosure provides a method for preparing peanut membrane extract, which obtains peanut membrane extract rich in polyphenols and proanthocyanidins and with significant α-amylase inhibitory activity by synergistically controlling the material-to-water ratio, extraction temperature and time, concentration factor, and sterilization conditions.

[0006] In a first aspect, the present disclosure provides a method for preparing peanut membrane extract, comprising the following steps:

[0007] (1) Raw material processing: drying and crushing the peanut membrane obtained after shelling peanuts to obtain peanut membrane raw material;

[0008] (2) Water extraction: mixing the peanut membrane raw material with water at a material-to-water ratio of 1:10 to 1:30, and extracting at a temperature of 60 to 90°C for 30 to 60 min to obtain peanut membrane initial extract;

[0009] (3) Filtration and concentration: filtering the peanut membrane initial extract to obtain peanut membrane filtrate; concentrating the peanut membrane filtrate by a concentration factor of 10 to 20 times to obtain peanut membrane concentrate;

[0010] (4) Sterilization: heat sterilizing the peanut membrane concentrate at a temperature of 80 to 100°C for 60 to 90 min to obtain peanut membrane extract (peanut membrane extract).

[0011] In one embodiment, in step (2), the water is reverse osmosis water and / or deionized water.

[0012] In one embodiment, in step (2), the extraction temperature is 65-85℃, more preferably 70-85℃.

[0013] In one embodiment, the soluble solids content of the peanut membrane extract at 20℃ is greater than 0.8 Brix. When the soluble solids content is greater than 0.8 Brix, it indicates that the water-soluble active ingredients in the peanut membrane have been effectively dissolved.

[0014] In one embodiment, step (3) further includes secondary filtration of the peanut membrane concentrate, preferably, the secondary filtration is performed using a 100-400 mesh filter.

[0015] In one embodiment, in step (3), the filtration is performed more than once using a 100-400 mesh filter.

[0016] In one embodiment, in step (3), the initial extract of peanut membrane is filtered using a 400-mesh filter, and the concentrated extract of peanut membrane is filtered a second time using a 100-mesh filter.

[0017] In one embodiment, in step (3), the concentration is carried out under reduced pressure.

[0018] In one embodiment, the soluble solids content of the peanut membrane concentrate at 20°C is 18-20 Brix.

[0019] By controlling the soluble solids content of the peanut membrane concentrate to 18-20 Brix and then performing heat sterilization, the polyphenols and proanthocyanidins can be significantly enriched while ensuring product stability, thereby endowing the obtained extract with excellent functional activity.

[0020] In one embodiment, in step (4), the sterilization temperature is 85-95°C and the sterilization time is 60-80 min.

[0021] In a most preferred embodiment, in step (4), the sterilization temperature is 95°C and the sterilization time is 70 min. The inventors have found that when the above-mentioned preferred sterilization temperature is used, combined with other process conditions of the present invention, the content of polyphenols and proanthocyanidins in the peanut membrane extract can be significantly increased, and its α-amylase inhibitory activity can be significantly increased.

[0022] In one embodiment, the method of this disclosure further includes step (5):

[0023] (5) Drying treatment: The peanut membrane extract obtained in step (4) is dried to obtain a peanut membrane extract in powder form.

[0024] In one embodiment, in step (5), the drying treatment is spray drying.

[0025] In one embodiment, in step (5), the obtained peanut membrane extract in powder form is sieved.

[0026] In a second aspect, this disclosure provides a peanut membrane extract prepared according to the method of the first aspect, wherein the peanut membrane extract is in liquid or powder form.

[0027] In one embodiment, the total polyphenol content in the peanut membrane extract is 20-40 g / 100 g.

[0028] In one embodiment, the proanthocyanidin content in the peanut membrane extract is 65-85 wt%.

[0029] In one embodiment, the α-amylase inhibition rate of the peanut membrane extract at 0.2 mg / mL, 0.25 v / v % or equivalent concentration is 30% or more.

[0030] In a third aspect, this disclosure provides the use of peanut membrane extract in the preparation of compositions for regulating blood sugar and / or antioxidation.

[0031] In one embodiment, the compositions of the present invention are used to inhibit the activity of α-amylase.

[0032] Compared with the prior art, the present invention has at least the following beneficial effects:

[0033] (1) By extracting peanut membrane raw material with water at a material-to-water ratio of 1:10 to 1:30 at a temperature of 60 to 90°C for 30 to 60 minutes, the extraction efficiency can be guaranteed while avoiding degradation of polyphenols and proanthocyanidins due to excessive heating;

[0034] (2) By filtering and concentrating the initial peanut membrane extract, the concentration ratio is controlled to be 10 to 20 times, so that the active ingredients are effectively enriched;

[0035] (3) The peanut membrane concentrate is further subjected to heat sterilization treatment at 80 to 100°C for 60 to 90 minutes, which can ensure the microbial safety of the product while avoiding significant loss of active ingredients, thereby obtaining a liquid peanut membrane extract with both stability and high activity;

[0036] (4) When a solid product is required, peanut membrane extract can be spray-dried and sieved appropriately to obtain peanut membrane extract powder with good flowability and uniform particle size, which is beneficial for storage, transportation and application in food or nutritional supplements;

[0037] (5) Due to the synergistic control of the above extraction, concentration and sterilization conditions, the total polyphenol and proanthocyanidin content of the peanut membrane extract prepared in this disclosure is significantly higher than that of the control sample without the above parameter control, and it shows excellent inhibition effect in the α-amylase inhibition experiment, indicating that it has good antioxidant capacity and potential function of regulating sugar metabolism;

[0038] (6) The process flow of the method disclosed in this disclosure is simple, the operating conditions are clear and easy to scale up industrially, the solvent used is water, which is safe and environmentally friendly and the cost is controllable. Brief Description of the Drawings

[0039] Figure 1A shows the UPLC spectra of compounds AH-01 to AH-06, with the molecular formula scanned: C30H24O12.

[0040] Figure 1B shows the UPLC spectra of compounds AH-07 to AH-08, with the molecular formula C15H14O6.

[0041] Figure 1C shows the UPLC spectra of compound AH-09, with the molecular formula C10H13N5O4.

[0042] Figure 2 shows the UPLC spectra of peanut membrane extract powder. Detailed Description

[0043] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure pertains.

[0044] In this document, the terms “comprising,” “having,” “including,” and “containing” should be interpreted as open-ended terms (i.e., meaning “including but not limited to”).

[0045] In the method of this disclosure, any commercially available peanut variety can be used as raw material. Exemplary varieties include the peanut (Arachis hypogaea) cultivar Tainong 11 and the large peanut series, such as Huayu 961, Huayu 25, Huayu 6803, Weihua 8, Luhua 14, and Jilin 11.

[0046] Unless otherwise stated, the following parameters involved in this disclosure are determined and defined as follows:

[0047] Soluble solids content: determined by refractive index at 20°C and expressed as Brix value, defined as the number of grams of soluble solids contained in 100 grams of solution.

[0048] Total polyphenol content: determined according to the Folin-Ciocalteu method, and the result is expressed as gallic acid equivalent.

[0049] Proanthocyanidin (OPC) content: determined by the hydrochloric acid-n-butanol colorimetric method, and the result is expressed as a percentage of proanthocyanidin mass equivalent to the standard.

[0050] α-Amylase inhibition rate: determined by in vitro spectrophotometry based on the 3,5-dinitrosalicylic acid method.

[0051] The present disclosure will be further described in detail below with reference to the accompanying drawings and embodiments. The following embodiments are for illustrative purposes only and are not intended to limit the scope of the disclosure. Experimental methods not specifically specified in the embodiments are performed under conventional conditions known in the art or under conditions recommended by the manufacturer.

[0052] Experimental Example 1: Preparation of Peanut Membrane Extract

[0053] The peanut membrane extract (peanut membrane extract) of Examples 1-4 was prepared by the following steps:

[0054] (1) Raw material treatment: The peanut membrane obtained after shelling peanuts was dried and crushed to obtain peanut membrane raw material;

[0055] (2) Water extraction: The peanut membrane raw material and reverse osmosis water (RO water) were mixed at a material-to-water ratio of 1:20. The mixture was placed in a constant temperature water bath (TKS, WB212-B2) and extracted at a temperature of 65-85℃ for 30 minutes to obtain the initial peanut membrane extract. The soluble solids content (Brix value) of the initial extract at 20℃ was measured to be >0.8;

[0056] (3) Filtration and concentration: The initial extract was filtered for the first time using a 400-mesh filter to obtain peanut membrane filtrate; The filtrate was then concentrated using a rotary vacuum concentrator (BUCHI series: BUCHI Pump V-300 & Rotavapor) R-300 & Heating bath B-300 Base) was concentrated to 1 / 20 of the original volume (i.e., concentrated 20 times), and filtered a second time with a 100-mesh filter to obtain peanut membrane concentrate (page 3 / 9 of the instruction manual, CN 121533529 A). The Brix value of the concentrate at 20℃ was measured to be 18-20.

[0057] (4) Sterilization treatment: The peanut membrane concentrate was heat sterilized at 85-100℃ for 60 min to obtain peanut membrane extract.

[0058] The peanut membrane extract (peanut membrane extract powder) of Examples 5-7 was prepared by the following steps:

[0059] (1) Raw material processing: The peanut membrane obtained after shelling peanuts was dried and crushed to obtain peanut membrane raw material;

[0060] (2) Water extraction: The peanut membrane raw material was mixed with reverse osmosis water (RO water) at a material-to-water ratio of 1:10 to 1:20. The mixture was placed in a constant temperature water bath (TKS, WB212-B2) and extracted at a temperature of 70-85℃ for 30-60 min to obtain the initial peanut membrane extract. The soluble solids content (Brix value) of the initial extract at 20℃ was measured to be >0.8;

[0061] (3) Filtration and concentration: The initial extract was filtered for the first time using a 400-mesh filter to obtain peanut membrane filtrate; The filtrate was then concentrated using a rotary vacuum concentrator (BUCHI series: BUCHI Pump V-300 & Rotavapor R-300 & Heating bath). B-300 Base) was concentrated to 1 / 10 to 1 / 20 of its original volume (i.e., concentrated 10 to 20 times), and filtered a second time with a 100-mesh filter to obtain peanut membrane concentrate. The Brix value of the concentrate at 20°C was measured to be 18-20.

[0062] (4) Sterilization treatment: The peanut membrane concentrate was heat-sterilized at 95°C for 70 min to obtain peanut membrane extract.

[0063] (5) Drying treatment: The peanut membrane extract obtained in step (4) was spray-dried and sieved through a 30-mesh filter to obtain peanut membrane extract in powder form.

[0064] Yield: According to the above process, about 80 g of peanut membrane extract or about 10 g of peanut membrane extract powder can be produced from 100 g of raw peanut membrane.

[0065] The specific process parameters of Examples 1-7 are shown in Table 1 below.

[0066] Table 1.

[0067]

[0068] Experimental Example 2: Detection of Peanut Membrane Extract

[0069] The total polyphenol content, proanthocyanidin content and α-amylase inhibition rate of the peanut membrane extracts obtained in Examples 1-7 were detected. The detection results are shown in Table 2. The detection methods are as follows.

[0070] I. Detection of Total Polyphenol Content

[0071] The total polyphenol content of the sample was determined by the Folin-Ciocalteu colorimetric method with gallic acid as the standard substance. Instruction manual 4 / 9 pages 6 CN 121533529 A

[0072] Gallic acid standard solutions of different concentrations were prepared. 100 μL of the standard solution was taken and Folin-Ciocalteu reagent and sodium carbonate solution were added sequentially. After reacting at room temperature, the absorbance was measured at a wavelength of 750 nm, and a standard curve was plotted.

[0073] After appropriate dilution, the peanut membrane extract sample was subjected to a colorimetric reaction and absorbance was measured using the same method as the standard solution. The equivalent concentration of gallic acid in the sample was calculated based on the standard curve, and the total polyphenol content of the peanut membrane extract was obtained by conversion based on the dilution factor. The results are expressed in g / 100 g.

[0074] II. Detection of Proanthocyanidin (OPC) Content

[0075] Using proanthocyanidin standard as a control, the proanthocyanidin content was determined by the acidic n-butanol-ferric ammonium sulfate method.

[0076] Proanthocyanidin standard solutions of different concentrations were prepared, and their absorbance or chromatographic response value at a wavelength of 525 nm was measured to plot a standard curve.

[0077] The peanut membrane extract sample was diluted with methanol and then ultrasonically treated. The supernatant was centrifuged and used as the test solution. The test solution was mixed with n-butanol-hydrochloric acid and ferric ammonium sulfate reagent, reacted under high temperature and cooled, filtered through a filter membrane, and the absorbance was measured at a wavelength of 525 nm. The proanthocyanidin content in the sample was calculated according to the standard curve.

[0078] III. Detection of α-amylase inhibition rate

[0079] The inhibitory effect of the sample on α-amylase activity was determined by the DNS colorimetric method.

[0080] The peanut membrane extract powder or peanut membrane extract sample was diluted with water at a set concentration, and the supernatant was taken as the test solution after centrifugation. Phosphate buffer was used as a blank control. The sample or blank was mixed with α-amylase and soluble starch substrate was added. DNS was added after a set time to terminate the reaction, and the mixture was heated for color development.

[0081] After the reaction solution was cooled, the absorbance was measured at a wavelength of 540 nm. The α-amylase inhibition rate was calculated based on the changes in absorbance of the sample group and the blank group at different reaction times.

[0082] Table 2.

[0083]

[0084] The detection results of total polyphenol content, proanthocyanidin content and α-amylase inhibition rate in Examples 1-7 are shown in Table 2 above. It can be seen that the peanut membrane extract prepared by the method of the present invention has a high content of polyphenols and proanthocyanidins, and exhibits a high α-amylase inhibitory ability, among which Examples 5-7 (especially Example 7) have the best comprehensive performance.

[0085] It is well known in the art that polyphenols and proanthocyanidins are widely proven to be potent natural antioxidants that can scavenge free radicals and reduce the damage of oxidative stress to cells. In addition, α-amylase is a key digestive enzyme in the human body responsible for breaking down starch into absorbable sugars. Therefore, by inhibiting the activity of α-amylase, the digestion rate of carbohydrates in the diet and the release rate of glucose can be slowed down, thereby helping to stabilize blood sugar. Specification 5 / 9 pages 7 CN 121533529 A

[0086] Experimental Example 3: Component Analysis of Peanut Membrane Extract

[0087] (I) Instruments and Reagents

[0088] The components of peanut membrane extract were analyzed by an ultra-high performance liquid chromatography-high resolution mass spectrometry system (UPLC-HR-MS / MS).The ultra-high performance liquid chromatograph was a Thermo Scientific Dionex Ultimate 3000 UHPLC system; the high resolution mass spectrometer was a Q Exactive™ Hybrid Quadrupole-Orbitrap Mass Spectrometer, and the detection results were expressed as m / z.

[0089] The chromatographic column was a HALO 90 Å C18 column with a particle size of 2 μm and a specification of 2.1 × 150 mm.

[0090] Compounds AH-01 to AH-08 were purchased from ChemFaces (Wuhan, China), and compound AH-09 was purchased from Merck.

[0091] (II) Preparation of standard solutions

[0092] 10 mg of each of compounds AH-01 to AH-09 were accurately weighed, added to a 50% (volume fraction) methanol aqueous solution, and diluted to a volumetric flask of 10 mL to prepare a stock solution with a concentration of 1000 μg / mL for each compound.

[0093] Subsequently, using the stock solution as the mother liquor, standard working solutions with concentrations of 1000, 500, 200, 100 and 50 ng / mL were prepared by stepwise dilution with 50% methanol aqueous solution. After filtration through a PVDF membrane, the solutions were used for further processing.

[0094] (III) Chromatographic-Mass Spectrometry Analysis Conditions

[0095] The chromatographic conditions are as follows:

[0096] Mobile phase A is methanol containing 0.1% formic acid, and mobile phase B is ultrapure water containing 0.1% formic acid;

[0097] The flow rate is 0.25 mL / min, the column temperature is set to 40 ℃, and the injection volume is 5 μL.

[0098] The gradient elution program is as follows: 0 min: A / B = 2 / 98; 1 min: A / B = 2 / 98; 4 min: A / B = 20 / 80; 20 min: A / B = 18 / 82; 28 min: A / B = 50 / 50; 28.1 min: A / B = 100 / 0; 30 min: A / B = 100 / 0.

[0099] The analysis time is 30 min.

[0100] The mass spectrometry conditions are as follows:

[0101] The high-resolution mass spectrometer is set to target molecular formula scanning mode, wherein the molecular formulas of AH-01 to AH-06 are , the molecular formulas of AH-07 and AH-08 are , and the molecular formula of AH-09 is .

[0102] (IV) Retention Time of Standards

[0103] Under the above analytical conditions, the chromatographic retention times of each standard compound are as follows:

[0104] AH-01: 11.26 min; AH-02: 23.16 min; AH-03: 19.30 min; AH-04: 11.87 min; AH-05: 17.91 min; AH-06: 25.88 min; AH-07: 7.47 min; AH-08: 10.68 min; AH-09: 3.77 min.

[0105] The results are shown in Figures 1A to 1C.

[0106] (V) Preparation and Analysis of Peanut Membrane Extract Samples

[0107] 200 mg of peanut membrane extract powder from Examples 5 to 7 was weighed, added to a 50% methanol aqueous solution, and diluted to a 10 mL volumetric flask to obtain a 50-fold diluted peanut membrane extract solution.

[0108] Subsequently, the peanut membrane extract solution was further diluted with 50% methanol aqueous solution to prepare 5000-fold and 25000-fold diluted solutions, respectively, and then filtered through a PVDF membrane for later use.

[0109] Samples from different batches were selected for testing. The sample batches included: Example 5, Example 6 and Example 7. The analysis results are shown in Figure 2 and Table 3.

[0110] Table 3. Compound content detection results (unit: ppm) Specification 6 / 9 pages 8 CN 121533529 A

[0111]

[0112] The structures of compounds AH-01 to AH-09 are shown in Table 4 below:

[0113] Table 4. Specification 7 / 9 pages 9 CN 121533529 A

[0114]

[0115] In summary, the peanut membrane extract obtained by the method of the present invention, which has both high concentration of active ingredients and specific enzyme inhibition function, shows clear application potential and development value in the fields of developing foods, health products or dietary supplements for regulating blood sugar and providing antioxidant effects. Instruction manual, pages 8 / 9, 10 CN 121533529 A

[0116] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art who makes equivalent substitutions or changes to the technical solution and inventive concept of the present invention within the scope of the technology disclosed in the present invention should be covered within the scope of protection of the present invention.DESCRIPTION 9 / 9 Page 11 CN 121533529 A Figure 1A Figure 1B Figure 1C DESCRIPTION ATTACHED DRAWINGS 1 / 2 Page 12 CN 121533529 A Figure 2 DESCRIPTION ATTACHED DRAWINGS 2 / 2 Page 13 CN 121533529 A The present invention relates to a method for preparing a peanut skin extract using peanut skin as a raw material, a peanut skin extract obtained by the method, and use of the extract in a composition (such as functional foods, health products or nutritional supplements). The method for preparing a peanut skin extract provided by the present invention, by optimizing an integrated process of raw material treatment, extraction, concentration and sterilization, can efficiently and stably produce a peanut skin extract having high contents of total polyphenols and oligomeric proanthocyanidins (OPCs) and excellent α-amylase inhibitory activity. The extract has clear development and application value in terms of blood glucose regulation, antioxidation, and the like.。

Claims

1. A method of preparing a peanut membrane extract, characterized by, The method comprises the following steps: (1) raw material processing: drying and crushing peanut film obtained after shelling peanut to obtain peanut film raw material; (2) water extraction: mixing the peanut film raw material with water at a material to water ratio of 1:10-1:30, extracting at a temperature of 60-90℃ for 30-60 min to obtain peanut film initial extraction liquid; (3) filtration and concentration: filtering the peanut film initial extraction liquid to obtain peanut film filtrate; concentrating the peanut film filtrate, the concentration multiple being 10-20, to obtain peanut film concentrated liquid; (4) sterilization treatment: heat sterilizing the peanut film concentrated liquid at a temperature of 80-100℃ for 60-90 min to obtain peanut film extract.

2. The method of claim 1, wherein, In step (2), the water is reverse osmosis water and / or deionized water.

3. The method of claim 1, wherein, The soluble solid content of the peanut film initial extraction liquid at 20℃ is greater than 0.8 Brix.

4. The method of claim 1, wherein, In step (3), the concentration is reduced pressure concentration; and / or the step (3) further comprises secondary filtration of the peanut film concentrated liquid.

5. The method of claim 1, wherein, The soluble solid content of the peanut film concentrated liquid at 20℃ is 18-20 Brix.

6. The method of claim 1, wherein, In step (4), the sterilization temperature is 85-95℃, and the sterilization time is 60-80 min.

7. The method according to any one of claims 1 to 6, characterized in that, The method further comprises step (5): (5) drying treatment: drying the peanut film extract obtained in step (4) to obtain peanut film extract in powder form.

8. The method of claim 7, wherein, The drying treatment is spray drying, and / or the obtained peanut film extract in powder form is subjected to sieving treatment.

9. A peanut membrane extract, characterized in that, The peanut film extract is obtained by the method of any one of claims 1-8, and the peanut film extract is in liquid or powder form.

10. The peanut membrane extract of claim 9, wherein, The total polyphenol content in the peanut film extract is 20-40 g / 100 g.

11. The peanut meal extract of claim 9 or 10, wherein, The proanthocyanidin content in the peanut film extract is 65-85wt%.

12. The peanut membrane extract of any one of claims 9 to 11, wherein, The α-amylase inhibition rate of the peanut film extract at 0.2 mg / mL, 0.25 v / v% or equivalent concentration is 30% or more.

13. Use of the peanut film extract of any one of claims 9-12 in the preparation of a composition for regulating blood sugar and / or antioxidant.

14. Use according to claim 13, wherein, The composition is used for inhibiting the activity of α-amylase.

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