阅读说明：本技术 一种从酱油渣中提取大豆异黄酮的方法 (Method for extracting soybean isoflavone from soy sauce residues ) 是由 程云辉 罗诗华 黄福气 许宙 焦叶 陈茂龙 于 2020-07-23 设计创作，主要内容包括：本发明涉及一种从酱油渣中提取大豆异黄酮的方法。该方法包括以下步骤：S1、乙醇提取：以乙醇为溶剂与酱油渣混合,得到大豆异黄酮粗提取液；S2、浓缩离心：将所述大豆异黄酮粗提取液浓缩、离心得到大豆异黄酮第一提取物；S3、二氯甲烷萃取：将所述二氯甲烷与所述大豆异黄酮第一提取物混合,得到大豆异黄酮第二提取物；S4、金属有机框架化合物吸附：将所述大豆异黄酮第二提取物与所述金属有机框架化合物混合,得到吸附有大豆异黄酮的金属有机框架化合物。本发明从酱油渣中高效率地提取纯度较高的大豆异黄酮。(The invention relates to a method for extracting soybean isoflavone from soy sauce residues. The method comprises the following steps: s1, ethanol extraction: mixing ethanol as solvent with soy sauce residue to obtain crude extract of soybean isoflavone; s2, concentration and centrifugation: concentrating and centrifuging the crude extract of the soybean isoflavone to obtain a first extract of the soybean isoflavone; s3, extraction with dichloromethane: mixing said dichloromethane with said first extract of soy isoflavones to obtain a second extract of soy isoflavones; s4, adsorption of metal organic framework compound: mixing the second extract of soy isoflavones with the metal-organic framework compound to obtain the soy isoflavone-adsorbed metal-organic framework compound. The invention efficiently extracts the soybean isoflavone with higher purity from the soy sauce residue.)

1. A method for extracting soy isoflavone from soy sauce residues is characterized by comprising the following steps:

s1, ethanol extraction: mixing ethanol as solvent with soy sauce residue to obtain crude extract of soybean isoflavone;

s2, concentration and centrifugation: concentrating and centrifuging the crude extract of the soybean isoflavone to obtain a first extract of the soybean isoflavone;

s3, extraction with dichloromethane: mixing said dichloromethane with said first extract of soy isoflavones to obtain a second extract of soy isoflavones;

s4, adsorption of metal organic framework compound: mixing the second extract of soy isoflavones with the metal-organic framework compound to obtain the soy isoflavone-adsorbed metal-organic framework compound.

2. The method according to claim 1, wherein after step S4, further comprising the steps of: s5, desorption: desorbing the metal organic framework compound adsorbed with the soybean isoflavone by using desorption liquid to obtain the soybean isoflavone.

3. The method according to claim 1, wherein in step S1, the soy sauce residue is mixed with the ethanol in a mass ratio of 1: 8-11.

4. The method as claimed in claim 1, wherein in step S1, the soy sauce residue is mixed with the ethanol and extracted at 60-80 ℃ for 3-5h to obtain the crude extract of soy isoflavone.

5. The method according to claim 1, wherein in step S1, the ethanol has a volume concentration of 60% -80%.

6. The method of claim 1, wherein in step S3, the dichloromethane is mixed with the first extract of soy isoflavones, followed by vacuum concentration to obtain a concentrated solution, and then washing the concentrated solution to obtain the second extract of soy isoflavones.

7. The method of claim 1, wherein in step S4, the metal-organic framework compound is MIL-100(Fe) material.

8. The method of claim 7, wherein the MIL-100(Fe) material is produced by:

FeCl is added₃·6H₂Mixing O, trimesic acid and water, performing ultrasonic treatment for 5-15min, and heating at 150-160 ℃ for 12-16 h.

9. The method according to claim 2, wherein in step S5, the desorption solution is ethanol, methanol, n-butanol, or ethyl acetate; the concentration of methanol is preferably 90% or more.

10. The method of claim 2, wherein desorbing the soy isoflavone-adsorbed metal-organic framework compound with methanol in step S5 specifically comprises: mixing the metal organic framework compound adsorbed with the soybean isoflavone with the methanol, carrying out ultrasonic treatment for 15-25min, standing for more than 40min, and centrifuging.

Technical Field

The invention relates to the technical field of agricultural and sideline product deep processing and food industry, in particular to a method for extracting soy isoflavone from soy sauce residues.

Background

The method for separating and refining isoflavone includes column chromatography (silica gel column chromatography, polyamide column chromatography, macroporous adsorbent resin column chromatography, etc.), membrane separation method and high speed countercurrent chromatography. The column chromatography can separate soybean isoflavone from the sample liquid by molecular sieve action and intermolecular force (hydrogen bond or Van der Waals force), and high-purity soybean isoflavone product can be obtained by the method; the membrane separation method separates the soybean isoflavone from other impurities based on the principle of molecular weight interception, and has the advantages of low energy consumption, high separation efficiency and simple process.

The high-speed counter-current chromatography is a liquid-liquid partition chromatography technology without a solid carrier, and the separation and purification are carried out by utilizing the solubility difference among compounds, so that the denaturation and decomposition of analytes are not caused, the product recovery rate is high, the purification effect is good, and the separation can be continuously carried out with high efficiency. MOFs are a class of crystalline porous polymer materials which are newly developed and consist of metal ions and organic framework ligands, and have the advantages of large specific surface area, large adsorption capacity, easily obtained preparation raw materials, strong designability, easy realization of specific selectivity and the like. Because MOFs materials can selectively adsorb by combining unsaturated sites, acid-base action, pi-pi complex formation, hydrogen bonding, electrostatic action and other principles, MOFs are used in many fields such as separation and storage, catalysis, drug delivery carriers, chemical sensing and the like. Therefore, the MOFs material can be applied to the refining and purification of various complex components as an effective and simple separation technology. The MIL-100(Fe) material is applied to enrichment and refining of soy isoflavone in soy sauce residues, and a method approach with high efficiency, environmental protection, economy and simple process is provided for refining soy sauce residue isoflavone.

Disclosure of Invention

The technical problem to be solved by the invention is as follows: how to efficiently extract soybean isoflavone with higher purity from soy sauce residue.

In order to solve the technical problems, the invention provides a method for extracting soy isoflavone from soy sauce residues.

The invention provides a method for extracting soybean isoflavone from soy sauce residues, which comprises the following steps:

s1, ethanol extraction: mixing ethanol as solvent with soy sauce residue to obtain crude extract of soybean isoflavone;

s2, concentration and centrifugation: concentrating and centrifuging the crude extract of the soybean isoflavone to obtain a first extract of the soybean isoflavone;

s3, extraction with dichloromethane: mixing said dichloromethane with said first extract of soy isoflavones to obtain a second extract of soy isoflavones;

s4, adsorption of metal organic framework compound: mixing the second extract of soy isoflavones with the metal-organic framework compound to obtain the soy isoflavone-adsorbed metal-organic framework compound.

Further, after step S4, the method further includes the steps of: s5, desorption: desorbing the metal organic framework compound adsorbed with the soybean isoflavone by using desorption liquid to obtain the soybean isoflavone.

Preferably, in step S1, the soy sauce residues and the ethanol are mixed according to a mass ratio of 1: 8-11.

Preferably, in step S1, the soy sauce residue is mixed with the ethanol and extracted at 60-80 ℃ for 3-5h to obtain the crude extract of soy isoflavone.

Preferably, in step S1, the ethanol has a volume concentration of 60% to 80%.

Preferably, in step S3, the dichloromethane is mixed with the first extract of soy isoflavones, followed by vacuum concentration to obtain a concentrated solution, and then the concentrated solution is washed to obtain the second extract of soy isoflavones. According to the principle of similarity and compatibility, isoflavone can be dissolved in dichloromethane, total sugar and ash can be dissolved in water phase, and organic phase can be obtained after liquid separation to remove total sugar and ash.

Preferably, in step S4, the metal-organic framework compound is an MIL-100(Fe) material.

Preferably, the MIL-100(Fe) material is prepared by:

FeCl is added₃·6H₂Mixing O, trimesic acid and water, performing ultrasonic treatment for 5-15min, and heating at 150-160 ℃ for 12-16 h.

Preferably, in step S5, the desorption solution is ethanol, methanol, n-butanol or ethyl acetate; the concentration of methanol is preferably 90% or more.

Preferably, in step S5, the desorbing the metal-organic framework compound having adsorbed soy isoflavones with methanol specifically includes: mixing the metal organic framework compound adsorbed with the soybean isoflavone with the methanol, carrying out ultrasonic treatment for 15-25min, standing for more than 40min, and centrifuging.

Compared with the prior art, the invention has the advantages that: the polarity of the ethanol is similar to that of the soybean isoflavone, and the soybean isoflavone in the soy sauce residue is extracted by using the ethanol according to the property of similar compatibility, so that the soybean isoflavone is dissolved in the ethanol to obtain a crude extract of the soybean isoflavone, and then the crude extract of the soybean isoflavone in the soy sauce residue is primarily purified by adopting a method of combining a concentration centrifugation method and a dichloromethane extraction method; the ethanol can be removed by concentrating the crude extract of the soybean isoflavone, the soybean isoflavone has stronger hydrophobicity due to the change of the polarity of the solution and is not dissolved in strong polar water to obtain a soybean isoflavone precipitate, the protein still remains in the water, then the precipitate is obtained by centrifugal sedimentation, the precipitate is washed and frozen and dried to obtain a first extract of the soybean isoflavone, so the protein in the crude extract of the soybean isoflavone can be effectively removed by concentration and centrifugation, then the total sugar and the ash in the first extract of the soybean isoflavone can be better removed by dichloromethane extraction, because the distribution coefficient of the isoflavone in the dichloromethane is higher and the distribution coefficient of the total sugar and the ash in the water phase is higher according to the similar intermiscibility principle, the organic phase can be obtained after the liquid separation to remove the total sugar and the ash to obtain a second extract of the soybean isoflavone, and the two-method combination can preliminarily and effectively remove the impurities in the crude extract of the soybean isoflavone, the purity of isoflavone is obviously improved; then adopting a metal organic framework compound for adsorption, further adsorbing the second extract of the soybean isoflavone to obtain the soybean isoflavone, wherein the metal organic framework compound has affinity to the soybean isoflavone in the soy sauce residue due to the hydrogen bond action, the chelation action with metal ions, the surface adsorption or the adsorption in pores of the soybean isoflavone and can selectively adsorb aglycone isoflavone (genistein, daidzein and daidzein) from the soy sauce residue, and particularly has the best adsorption effect on the genistein; the recovery rate of the soybean isoflavone is 80.31 percent, and the purity of the soybean isoflavone is up to 56.17 percent.

Drawings

The features and advantages of the present invention will be more clearly understood by reference to the accompanying drawings, which are illustrative and not to be construed as limiting the invention in any way, and in which:

FIG. 1 is a process flow diagram of a method for extracting soy isoflavones from soy sauce residues.

FIG. 2 is a schematic diagram of the adsorption of soy isoflavones in soy sauce residue by MIL-100(Fe) material.

FIG. 3 is a graph showing the effect of the amount of MIL-100(Fe) material on static adsorption in example 1 of the present invention.

FIG. 4 is a graph showing the effect of the concentration of the second extract of soybean isoflavones on the static adsorption in example 1 of the present invention.

FIG. 5 is a graph showing the effect of different desorption solutions on the desorption rate of soy isoflavones in example 1 of the present invention.

FIG. 6 is a graph showing the effect of methanol concentrations on the desorption rate of soy isoflavones in example 1 of the present invention.

Detailed Description

In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in detail below. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein, but rather should be construed as broadly as the present invention is capable of modification in various respects, all without departing from the spirit and scope of the present invention.

The embodiment mode provides a method for extracting soy isoflavone from soy sauce residues by combining the following steps:

s1, ethanol extraction: mixing the soy sauce residues with ethanol according to the mass ratio of 1:8-11, and extracting at 60-80 ℃ for 3-5h to obtain a crude extract of the soybean isoflavone; wherein the volume concentration of the ethanol is 60-80%;

s2, concentration and centrifugation: concentrating the crude extract of soybean isoflavone to 1/4-1/2 of which the liquid is the original volume, specifically carrying out rotary evaporation in a rotary evaporator at 60 ℃ to 1/4-1/2 of which the liquid is the original volume, then centrifuging under the condition of 3500-4500r/min, then adding water, stirring, mixing for 20-30 min, centrifuging again, pouring out water washing liquid to obtain a soybean isoflavone precipitate, and carrying out freeze drying on the soybean isoflavone precipitate to obtain a first extract of the soybean isoflavone;

s3, extraction with dichloromethane: adding water into the first extract to disperse the first extract in water, then adding equal volume of dichloromethane, stirring at 550rpm/min for 0.5-1 h, transferring to a separating funnel, standing for more than 1h, separating, extracting for 3-4 times, combining extracted organic solvent phases, then carrying out vacuum concentration to obtain a concentrated solution, and washing the concentrated solution with distilled water to obtain a second extract of the soybean isoflavone;

s4, adsorption of metal organic framework compound: mixing the second extract of soy isoflavones with the metal-organic framework compound to obtain a metal-organic framework compound having soy isoflavones adsorbed thereon; the metal-organic framework compound is preferably a MIL-100(Fe) material;

wherein the MIL-100(Fe) material is prepared by the following steps:

FeCl is added₃·6H₂Mixing O, trimesic acid and water, performing ultrasonic treatment for 5-15min, and heating at 150-160 ℃ for 12-16 h.

S5, desorption: mixing the metal organic framework compound adsorbed with the soybean isoflavone with desorption solution, performing ultrasonic treatment for 15-25min, standing for more than 40min, and centrifuging to obtain the soybean isoflavone; the desorption solution is ethanol, methanol, n-butanol or ethyl acetate; the concentration of methanol is preferably 90% or more.

To further illustrate the methods set forth in the detailed description of the invention, the following examples are presented for a detailed description.