Special dietary food containing prebiotics
By preparing a magnetic anthocyanin extractant, the problem of low anthocyanin extraction efficiency was solved, achieving efficient and selective extraction and enrichment of proanthocyanidins from black rice, thus enhancing the effects of prebiotic foods.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-29
- Publication Date
- 2026-03-24
AI Technical Summary
Existing anthocyanin extraction methods are inefficient and prone to degradation, lacking selective and specific enrichment methods, which affects their application in prebiotic products.
A method for preparing magnetic anthocyanin extractant was developed by self-assembling quercetin and di(carboxy)allyl monomers into polymer molecules, combined with γ-MPS-modified Fe3O4 nanoparticles, to selectively extract proanthocyanidins from black rice. These extractants were then combined with inulin and fructooligosaccharides to form prebiotics, and supplemented with other nutrients to prepare special dietary foods.
This method achieves highly efficient and selective extraction and enrichment of proanthocyanidins from black rice, improving extraction efficiency, avoiding anthocyanin degradation, and enhancing the effects of prebiotic foods.
Smart Images
Figure CN121714040A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of black rice proanthocyanidin extraction, in particular to a special diet food containing prebiotics. BACKGROUND
[0002] Prebiotics refer to substances that can promote the growth of one or several microorganism colonies, thereby improving the health of the host and having a beneficial effect on the body. At present, the recognized prebiotics are mainly some oligosaccharides and the like; and the microorganisms that play an important role in the health of the host are called probiotics. A large number of in vitro experiments have proved that proanthocyanidins are a kind of potential prebiotics that can promote the growth of probiotics.
[0003] The surface of black rice contains proanthocyanidins, which are a kind of polyphenolic compounds. At present, the main method for extracting and enriching proanthocyanidins is solvent extraction, which may cause the degradation of proanthocyanidins during the extraction process. Selective and specific enrichment of proanthocyanidins can improve the efficiency of the extraction process and effectively avoid the purification process. Therefore, it is of important application value to establish a selective and specific adsorption method for proanthocyanidins. SUMMARY
[0004] The present application provides a method for extracting black rice proanthocyanidins, which combines black rice proanthocyanidins with inulin and fructooligosaccharides as prebiotic combinations, supplemented with other nutrients to prepare a special diet food containing prebiotics.
[0005] A method for extracting black rice proanthocyanidins, comprising the following steps:
[0006] Step one, preparation of magnetic proanthocyanidin extractant: quercetin as template molecule, di(carboxyl)allyl monomer as functional monomer, mixing under room temperature, the phenolic hydroxyl group of quercetin is ionically combined with the piperazinyl group of di(carboxyl)allyl monomer and hydrogen-bonded with the carbonyl group of di(carboxyl)allyl monomer to self-assemble into a polymeric molecule, then γ-MPS modified Fe3O4 nanoparticles, ethylene glycol dimethacrylate and azobisisobutyronitrile are added, sealed after nitrogen is introduced, oscillation reaction, magnetic separation of the product, removal of quercetin molecules using an eluent, and then the magnetic proanthocyanidin extractant is obtained;
[0007] Step two, crushing, grinding, and sieving of black rice, adding acetone, extracting under water bath at 45-60℃, centrifugation, and obtaining the extract; the extract is concentrated under reduced pressure in a rotary evaporator to obtain a mother liquor, then the magnetic proanthocyanidin extractant is added, and the mixture is placed in a constant temperature oscillator for oscillation extraction at room temperature, the magnetic proanthocyanidin extractant is magnetically separated, and the black rice proanthocyanidins are oscillated and precipitated.
[0008] Preferably, the eluent is composed of 9 parts by volume of methanol and 1 part by volume of acetic acid.
[0009] Preferably, the preparation method of the di(carboxyl)allyl monomer is as follows:
[0010] In step S1, by using a nucleophilic addition reaction mechanism, using aminoethylpiperazine as a nucleophile, the primary amino functional group of the aminoethylpiperazine reacts with the epoxy functional group of the allyl glycidyl ether to generate a piperazinyl allyl monomer through an epoxy ring-opening reaction;
[0011] In step S2, by using a Michael addition reaction mechanism, using the piperazinyl allyl monomer as a nucleophile, an amino-alkene addition reaction occurs between the amino functional group of the piperazinyl allyl monomer and the alpha, beta-alkenyl functional group of the methacrylic acid to generate a di(carboxyl)allyl monomer.
[0012] The black rice proanthocyanidins obtained according to the method for extracting black rice proanthocyanidins are combined with inulin and fructooligosaccharides as prebiotics, and are supplemented with konjac powder, soybean protein isolate, phytol, xylose alcohol, taro powder and sucralose to prepare special dietary foods containing prebiotics.
[0013] Compared with the prior art, the present application has the following beneficial technical effects:
[0014] The present application: a new functional monomer, pyridyl imine methacryloyloxy monomer, is synthesized; quercetin is used as a template molecule; the phenolic hydroxyl group of the quercetin is ionically combined with the piperazinyl group of the di(carboxyl)allyl monomer and is hydrogen-bonded with the carbonyl group of the di(carboxyl)allyl monomer to self-assemble into a polymer molecule; a magnetic quercetin extractant is prepared through a free radical polymerization method; and it is found that the magnetic quercetin extractant can extract proanthocyanidins from black rice. BRIEF DESCRIPTION OF DRAWINGS
[0015] Figure 1 is the chemical structural formula of the piperazinyl allyl monomer;
[0016] Figure 2 is the chemical structural formula of the di(carboxyl)allyl monomer;
[0017] Figure 3 is the chemical structural formula of quercetin;
[0018] Figure 4 is a structural schematic diagram of the self-assembly of quercetin and the di(carboxyl)allyl monomer into a polymer molecule. DETAILED DESCRIPTION
[0019] Experimental Example 1:
[0020] The reaction mechanism for synthesizing the piperazinyl allyl monomer is as follows: using the nucleophilic addition reaction mechanism, using aminoethyl piperazine as the nucleophile, the primary amino functional group of the aminoethyl piperazine reacts with the epoxy functional group of the allyl glycidyl ether to generate the piperazinyl allyl monomer, the chemical structural formula of which is shown in Figure 1 ;
[0021] The specific steps for synthesizing the piperazinyl allyl monomer are as follows: 10 mL of aminoethyl piperazine and 30 mL of methanol are added to a flask, nitrogen is introduced for protection, and a mixed solution composed of 9 mL of allyl glycidyl ether and 45 mL of methanol is added dropwise using a constant-pressure dropping funnel under stirring in an ice-water bath. After the dropwise addition is completed, stirring is performed at room temperature for 8 h, rotary evaporation is performed, and recrystallization is performed using tetrahydrofuran to obtain the piperazinyl allyl monomer.
[0022] Experimental Example 2
[0023] The reaction mechanism for synthesizing the di(carboxyl) allyl monomer is as follows: using the Michael addition reaction mechanism, using the piperazinyl allyl monomer as the nucleophile, an amino-alkene addition reaction occurs between the amino (NH) functional group of the piperazinyl allyl monomer and the α,β-alkyl functional group of the methacrylic acid to generate the di(carboxyl) allyl monomer, the chemical structural formula of which is shown in Figure 2 ;
[0024] The specific steps for synthesizing the di(carboxyl) allyl monomer are as follows: 6.5 g of the piperazinyl allyl monomer and 80 mL of chloroform are placed in a four-necked flask, nitrogen is introduced for protection, and 6.8 mL of methacrylic acid is added dropwise using a constant-pressure dropping funnel under uniform stirring. After the dropwise addition is completed, heating is performed at 40°C in a constant-temperature water bath for 6 h, and chloroform is removed by normal-pressure distillation to obtain the di(carboxyl) allyl monomer, the chemical structural characterization of which is as follows: using CDCl3 as the solvent, 1 H NMR characterization results are as follows: 1 H NMR (400 MHz, δ / ppm): 1.11-1.13 (d, 6H), 2.52-2.78 (m, 14H), 2.89-2.95 (m, 4H), 3.21-3.24 (m, 2H), 3.47-3.55 (m, 2H), 3.89-3.95 (m, 1H), 4.01-4.03 (d, 2H), 5.19-5.25 (m, 2H), 5.85-5.93 (m, 1H); wherein, in the CDCl3 solvent, the carboxyl H of the di(carboxyl) allyl monomer is a labile hydrogen, which does not peak here.
[0025] Example 1
[0026] Preparation of 3-(methacryloyloxy)propyl trimethoxysilane (γ-MPS) modified Fe3O4 nanoparticles: Under argon protection, 80 mL of 0.5 mol / L NaOH solution was added into a reactor, and a mixed solution (consisting of 1 volume part of ultrapure water and 1 volume part of anhydrous ethanol) dissolving 1.12 g of ferrous sulfate heptahydrate and 2.16 g of ferric chloride hexahydrate was added dropwise into the reactor at 75°C in a water bath. After the dropwise addition was completed, the reaction was kept at 80°C in the water bath for 0.5 h. Then, 1 mL of 3-(methacryloyloxy)propyl trimethoxysilane was added, and the mixture was allowed to mature at 50°C for 0.5 h. After cooling, the product was separated by magnetic separation, washed until neutral, washed with anhydrous ethanol, and dried at 40°C under vacuum for 24 h to obtain γ-MPS modified Fe3O4 nanoparticles.
[0027] Example 2:
[0028] Preparation of magnetic anthocyanin extractant: 25 mg of quercetin (the chemical structural formula of which is shown in Figure 3 ) and 0.156 g of di(carboxyl)allyl monomer were added into 20 mL of acetonitrile, and the mixture was shaken at room temperature for 2 h. The phenolic hydroxyl groups of quercetin were self-assembled into polymeric molecules (the chemical structural formula of which is shown in Figure 4 ) through ionic interaction with the piperazinyl groups of the di(carboxyl)allyl monomer and hydrogen bonding interaction with the carbonyl groups of the di(carboxyl)allyl monomer. Then, 50 mg of γ-MPS modified Fe3O4 nanoparticles, 0.75 mL of ethylene glycol dimethacrylate, and 15 mg of azobisisobutyronitrile were added. After being purged with nitrogen for 10 min, the mixture was sealed and kept at 60°C for 24 h of constant temperature oscillation reaction. The product was separated by magnetic separation, washed with anhydrous ethanol and distilled water, and then extracted with an extraction solution consisting of 9 volume parts of methanol and 1 volume part of acetic acid for 24 h to elute the quercetin molecules. The mixture was dried at 60°C under vacuum for 12 h to obtain the magnetic anthocyanin extractant.
[0029] Example 3:
[0030] Static extraction of black rice proanthocyanidins: 1 g of black rice was ground and sieved through a 150-mesh sieve, and then added into 30 mL of acetone. The mixture was extracted at 55°C in a water bath for 1 h, and then centrifuged to obtain an extract. The extract was concentrated under reduced pressure in a rotary evaporator to obtain 20 mL of a mother liquor. Then, 100 mg of the magnetic anthocyanin extractant was added, and the mixture was placed in a constant temperature oscillator and shaken at room temperature at a rotation speed of 100 r / min for 2 h. The magnetic anthocyanin extractant was separated by magnetic separation, and the absorbance of the mother liquor and the extracted product was measured. The results were as follows: the concentration of proanthocyanidins in the mother liquor was 48.2 μg / mL, and the concentration of proanthocyanidins after extraction was 1.6 μg / mL.
[0031] The proanthocyanidins extracted by the magnetic anthocyanin extractant were shaken and precipitated using a mixed solvent (consisting of 9 volume parts of methanol and 1 volume part of acetic acid), and the solvent was removed to obtain black rice proanthocyanidins.
[0032] Determination of the absorbance of proanthocyanidins in black rice: Transfer 2.0 mL of the proanthocyanidin solution to be tested, add 3.0 mL of colorimetric reagent, dilute to 10 mL with ethanol, mix thoroughly, and let stand in the dark for 1 h. Use the ethanol solution to replace the sample solution for a blank control test. Measure the absorbance at 500 nm using a UV-Vis spectrophotometer. Based on the relationship between the concentration of the sample solution and the absorbance, plot the proanthocyanidin standard curve with the concentration of the proanthocyanidin standard as the abscissa (x) and the measured absorbance value as the ordinate (y), and obtain the regression equation.
[0033] Example 4:
[0034] Special dietary foods containing prebiotics: These are prepared by combining black rice proanthocyanidins, inulin, and fructooligosaccharides as prebiotics, supplemented with konjac flour, soy protein isolate, phytosterol esters, xylitol, taro powder, and sucralose.
Claims
1. A method for extracting proanthocyanidins from black rice, characterized in that, Includes the following steps: Step 1: Preparation of magnetic anthocyanin extractant: Quercetin is used as the template molecule and di(carboxy)allyl monomer as the functional monomer. The mixture is shaken and mixed at room temperature. The phenolic hydroxyl group of quercetin self-assembles into a polymer molecule through ionic interaction with the piperazine group of the di(carboxy)allyl monomer and hydrogen bonding with the carbonyl group of the di(carboxy)allyl monomer. γ-MPS modified Fe3O4 nanoparticles, ethylene glycol dimethacrylate and azobisisobutyronitrile are added. After purging with nitrogen, the mixture is sealed and subjected to oscillation reaction. The product is magnetically separated, and quercetin molecules are removed using an eluent to obtain the magnetic anthocyanin extractant. Step 2: Crush and grind the black rice, sieve it, add acetone, extract it in a water bath at 45~60℃, centrifuge it to obtain the extract; The extract was concentrated under reduced pressure in a rotary evaporator to obtain a mother liquor. Magnetic anthocyanin extractant was added, and the mixture was placed in a constant temperature shaker for extraction at room temperature. The magnetic anthocyanin extractant was magnetically separated, and black rice proanthocyanidins were precipitated by shaking.
2. The method for extracting proanthocyanidins from black rice according to claim 1, characterized in that, The eluent consists of 9 parts by volume of methanol and 1 part by volume of acetic acid.
3. The method for extracting proanthocyanidins from black rice according to claim 1, characterized in that, The preparation method of the di(carboxy)allyl monomer is as follows: Step S1: Utilizing the nucleophilic addition reaction mechanism, aminoethylpiperazine is used as a nucleophile. The primary amino functional group of aminoethylpiperazine undergoes an epoxy ring-opening reaction with the epoxy functional group of allyl glycidyl ether to generate piperazine allyl monomer. Step S2 utilizes the Michael addition reaction mechanism, using piperazine allyl monomer as a nucleophile, and generates di(carboxy)allyl monomer through an amino-olefin addition reaction between the amino functional group of piperazine allyl monomer and the α,β-olefinic functional group of methacrylic acid.
4. The black rice proanthocyanidins obtained by the method of extracting black rice proanthocyanidins according to any one of claims 1-3 are combined with inulin and fructooligosaccharides as a prebiotic combination, and then mixed with konjac flour, soy protein isolate, phytosterol esters, xylitol, taro powder and sucralose to prepare a special dietary food containing prebiotics.