阅读说明：本技术 一种柑橘皮渣综合利用方法 (Comprehensive utilization method of citrus peel residues ) 是由 周志钦 李真晴 陈欣 田思宇 于 2020-05-30 设计创作，主要内容包括：本发明公开了一种柑橘皮渣综合利用方法,包括用皮渣碳吸附的步骤,所述步骤包括：S301：配置吸附液,用乙醇溶液溶解柑橘皮浸膏,过滤得上清液,调节所述上清液PH值5至7；S302：吸附,将所述吸附液加入放有皮渣碳的容器中,在恒温水浴振荡条件下震荡吸附,吸附完成后,过滤得滤渣；S303：解吸附,以乙醇溶液为解吸液,对滤渣进行解吸附,洗脱皮渣碳上吸附的多甲氧基黄酮,过滤,收集滤液,将获得的所述滤液真空浓缩至原体积的1/5至1/15,得浓缩洗脱液；S304：冷却结晶,向所述浓缩洗脱液中加入去离子水,于4℃下静置结晶,收集结晶产物获得多甲氧基黄酮混合物。本发明对柑橘皮渣利用充分,不仅制备了皮渣多孔碳,还从皮渣提取物中获得6个PMFs单体,纯度高。(The invention discloses a comprehensive utilization method of citrus peel residues, which comprises the step of adsorbing by peel residue carbon, and the step comprises the following steps: s301: preparing an adsorption solution, dissolving the citrus peel extract by using an ethanol solution, filtering to obtain a supernatant, and adjusting the pH value of the supernatant to 5-7; s302: adsorbing, namely adding the adsorption solution into a container containing the skin residue carbon, oscillating and adsorbing under the oscillating condition of constant-temperature water bath, and filtering to obtain filter residue after adsorption is finished; s303: desorbing the filter residue by using an ethanol solution as desorption liquid, eluting the polymethoxylated flavone adsorbed on the carbon of the skin residue, filtering, collecting filtrate, and concentrating the obtained filtrate in vacuum to 1/5-1/15 of the original volume to obtain concentrated eluent; s304: cooling for crystallization, adding deionized water into the concentrated eluent, standing for crystallization at 4 ℃, and collecting a crystallization product to obtain a polymethoxylated flavone mixture. The method fully utilizes the citrus peel residues, not only prepares peel residue porous carbon, but also obtains 6 PMFs monomers from the peel residue extract, and has high purity.)

1. A method for comprehensively utilizing citrus peel residues is characterized by comprising a step of carbon adsorption of citrus peel residues (S3).

2. The method for comprehensively utilizing the citrus peel residues according to claim 1, which is characterized in that: the step of carbon adsorption with citrus peel (S3) comprises:

s301: preparing an adsorption solution, dissolving the citrus peel extract by using an ethanol solution, filtering to obtain a supernatant, and adjusting the pH value of the supernatant to 5-7;

s302: adsorbing, namely adding the adsorption solution into a container containing the citrus peel residue carbon, oscillating and adsorbing under the oscillating condition of constant-temperature water bath, and filtering to obtain filter residue after adsorption is finished;

s303: desorbing the filter residue by using an ethanol solution as desorption liquid, eluting the polymethoxyflavone adsorbed on the carbon of the citrus peel residue, filtering, collecting filtrate, and concentrating the obtained filtrate in vacuum to 1/5-1/15 of the original volume to obtain concentrated eluent;

s304: cooling for crystallization, adding deionized water into the concentrated eluent, standing for crystallization at the temperature of below 10 ℃, and collecting a crystallization product to obtain a polymethoxylated flavone mixture.

3. The method for comprehensively utilizing the citrus peel residues according to claim 1, which is characterized in that: the preparation method of the citrus peel residue carbon comprises the following steps:

s201: crushing citrus peel residues to obtain peel residue powder, and uniformly mixing the peel residue powder with an activating agent and deionized water;

s202: magnetic stirring and activating;

s203: drying, and heating to 500-800 ℃ under the protection of nitrogen;

s204: washing with hydrochloric acid and ultrapure water until pH is greater than or equal to 5, and drying to constant weight.

4. The method for comprehensively utilizing the citrus peel residues according to claim 2, which is characterized in that: further comprising the steps of:

s401: dissolving the polymethoxyflavone mixture with methanol, and separating and purifying by mass spectrum guided prep-HPLC after passing through a PTFE membrane;

s402: automatically collecting each fraction according to retention time and mass spectrum data; classifying, mixing and evaporating the fractions to dryness;

s403: dissolving with absolute ethyl alcohol, adding an anti-solvent ultrapure water, and crystallizing for 24 hours to obtain crystals;

s404: washed with deionized water at 0-6 deg.c and dried to constant weight.

5. The method for comprehensively utilizing the citrus peel residues according to claim 2, which is characterized in that: the preparation method of the citrus peel extract comprises the following steps:

s101: crushing the citrus peel residues, adding an ethanol solution for soaking, heating and refluxing for 2 times, combining the two filtrates for 2 times, and concentrating, wherein the concentration specific gravity is 1.1-1.35.

6. The method for comprehensively utilizing the citrus peel residues according to claim 3, which is characterized in that: the activating agent is one or more of potassium carbonate, zinc chloride, potassium hydroxide and phosphoric acid.

7. The method for comprehensively utilizing the citrus peel residues according to claim 3, which is characterized in that: in step S203, the drying method is freeze drying or oven drying; wherein the drying temperature is below 55 ℃.

8. The method for comprehensively utilizing the citrus peel residues according to claim 3, which is characterized in that: the slag powder, the activating agent and the deionized water are mixed according to the weight ratio of 1: 1-5: mixing uniformly according to a mass-volume ratio of 80-120, wherein the weight of the slag powder and the activator is calculated, the volume of the deionized water is calculated, and the corresponding units are respectively gram and milliliter or are adjusted in the same proportion;

the temperature of the magnetic stirring activation in the step S202 is 30-50 ℃, and the activation time is 7-9 hours;

in the step S203, the heating speed is 3-10 ℃/min, and the temperature is maintained for 30-60 min after the heating is carried out to 500-800 ℃;

in the step S204, the drying is carried out at 40-60 ℃.

9. The method for comprehensively utilizing the citrus peel residues according to claim 2, which is characterized in that:

in the step S301, dissolving the citrus peel extract by using 25-30% ethanol solution;

the temperature of the water bath of the constant-temperature water bath oscillation in the step S302 is 20-30 ℃, and the oscillation speed is 110-140 rpm;

washing the filter residue with 5-10% ethanol solution for 5-20 times before desorption in the step S303;

in the step S303, the volume fraction of the ethanol solution used for desorption is more than 90%, the volume of the consumption of the desorption solution is 250-500 times of the mass of the carbon in the skin residue, wherein the volume is measured by milliliters, and the mass is calculated by grams or the same proportion;

in the step S303, the concentration temperature is set to be 30-60 ℃.

10. The method for comprehensively utilizing the citrus peel residues as claimed in claim 4, which is characterized in that: the pore diameter of the PTFE membrane is 0.22 mu m; the mobile phase adopted by prep-HPLC comprises a mobile phase A and a mobile phase B, wherein the mobile phase A is a 0.1% formic acid acetonitrile solution, the mobile phase B is a 0.1% formic acid aqueous solution, and the flow rate is set to be 20 mL/min; the elution gradient is 0-6 min, and 18% -30% of mobile phase A; 30-42% of mobile phase A for 6-35 min; 35-45 min, 42-60% of mobile phase A; 45-50 min, 60-18% of mobile phase A; the injection volume is 650 mu L;

in the step S403, adding an anti-solvent ultrapure water, the volume of which is 3-7 times of the volume of the original solution, and crystallizing for more than 24 hours at the temperature of 1-10 ℃;

in step S404, the number of times of washing with deionized water is 3 or more.

Technical Field

The invention relates to the technical field of plant component extraction, in particular to a comprehensive utilization method of citrus peel and residue.

Background

The orange processing produces a large amount of peel residues, and the current main resource utilization and treatment modes include sanitary landfill treatment, drying for making animal feed, extracting effective active substances, producing organic fertilizers and the like. The orange peel residue is easy to mildew and smell during landfill treatment, and causes serious pollution to the environment; processing citrus peel residues into feed consumes a large amount of energy, and is unreasonable from the aspects of environment and economy. The extracted effective active substances are mainly concentrated on the aspects of cellulose, soluble sugar, essential oil, pigment, pectin and the like, or a certain bioactive substance is singly extracted, and the citrus peel residue is not fully utilized. The citrus peel dregs are rich in polymethoxyflavone, and the extraction mainly adopts an acid extraction salt precipitation method, an organic solvent impregnation method, a supercritical fluid extraction method, a microwave/ultrasonic auxiliary method and the like. The method has low extraction efficiency, high energy consumption and low content of target substances in the crude extract. The separation and purification of effective active Substances (PMFs) mainly depend on silica gel column chromatography, macroporous resin adsorption, solvent extraction, Thin Layer Chromatography (TLC), membrane separation, high-speed countercurrent chromatography (HSCCC), preparative high performance liquid chromatography (prep-HPLC) and other modes. Among them, silica gel column chromatography is a traditional method for separating and purifying PMFs, but the steps are complicated, organic reagents are difficult to recover, and time and energy are consumed. High-speed countercurrent chromatography (HSCCC) has good separation effect and high product quality, but has higher requirements on equipment and operation level and is not easy to master. Macroporous adsorbent resins are widely used due to their high adsorption/desorption capacity and low cost, but the safety of MAR in the food and pharmaceutical industries is still under consideration.

Therefore, the technical personnel in the field strive to develop a comprehensive utilization method of the citrus peel residues, which has simple process, various extracts, high respective purity and high peel residue utilization rate.

Disclosure of Invention

In view of the above defects in the prior art, the present invention provides a method for comprehensively utilizing citrus peel and pomace, which has the advantages of simple process, multiple extract types, high purity of the extract, and high utilization rate of peel and pomace.

In order to achieve the purpose, the invention provides a comprehensive utilization method of citrus peel residues, which comprises the step of carbon adsorption of the citrus peel residues.

Preferably, the step of adsorbing with citrus peel carbon comprises:

s301: preparing an adsorption solution, dissolving the citrus peel extract by using an ethanol solution, filtering to obtain a supernatant, and adjusting the pH value of the supernatant to 5-7;

s302: adsorbing, namely adding the adsorption solution into a container containing the citrus peel residue carbon, oscillating and adsorbing under the oscillating condition of constant-temperature water bath, and filtering to obtain filter residue after adsorption is finished;

s303: desorbing the filter residue by using an ethanol solution as desorption liquid, eluting the polymethoxyflavone adsorbed on the carbon of the citrus peel residue, filtering, collecting filtrate, and concentrating the obtained filtrate in vacuum to 1/5-1/15 of the original volume to obtain concentrated eluent;

s304: cooling and crystallizing, adding deionized water into the concentrated eluent, standing and crystallizing at 10 ℃, and collecting a crystallized product to obtain a polymethoxylated flavone mixture.

Preferably, the preparation method of the citrus peel residue carbon comprises the following steps:

s201: crushing citrus peel residues to obtain peel residue powder, and uniformly mixing the peel residue powder with an activating agent and deionized water;

s202: magnetic stirring and activating;

s203: drying, and heating to 500-800 ℃ under the protection of nitrogen;

s204: washing with hydrochloric acid and ultrapure water until pH is greater than or equal to 5, and drying to constant weight.

Preferably, the method further comprises the following steps:

s401: dissolving the polymethoxyflavone mixture with methanol, and separating and purifying by mass spectrum guided prep-HPLC after passing through a PTFE membrane;

s402: automatically collecting each fraction according to retention time and mass spectrum data; classifying, mixing and evaporating the fractions to dryness;

s403: dissolving with absolute ethyl alcohol, adding an anti-solvent ultrapure water, and crystallizing for 24 hours to obtain crystals;

s404: washed with deionized water at 0-6 deg.c and dried to constant weight.

Preferably, the preparation of the citrus peel extract comprises the following steps:

s101: crushing the citrus peel residues, adding an ethanol solution for soaking, heating and refluxing for 2 times, combining the two filtrates for 2 times, and concentrating, wherein the concentration specific gravity is 1.1-1.35;

preferably, the activating agent is one or more of potassium carbonate, zinc chloride, potassium hydroxide and phosphoric acid.

Preferably, in step S203, the drying method is freeze drying or oven drying; wherein the drying temperature is below 55 ℃.

Preferably, the slag powder, the activating agent and the deionized water are mixed according to the weight ratio of 1: 1-5: mixing uniformly according to a mass-volume ratio of 80-120, wherein the weight of the slag powder and the activator is calculated, the volume of the deionized water is calculated, and the corresponding units are respectively gram and milliliter or are adjusted in the same proportion;

the temperature of the magnetic stirring activation in the step S202 is 30-50 ℃, and the activation time is 7-9 hours;

in the step S203, the heating speed is 3-10 ℃/min, and the temperature is maintained for 30-60 min after the heating is carried out to 500-800 ℃;

in the step S204, the drying is carried out at 40-60 ℃.

Preferably, in the step S301, 25% -30% ethanol solution is used for dissolving the citrus peel extract;

the temperature of the water bath of the constant-temperature water bath oscillation in the step S302 is 20-30 ℃, and the oscillation speed is 110-140 rpm;

washing the filter residue with 5-10% ethanol solution for 5-20 times before desorption in the step S303;

in the step S303, the volume fraction of the ethanol solution used for desorption is more than 90%, the volume of the consumption of the desorption solution is 250-500 times of the mass of the carbon in the skin residue, wherein the volume is measured by milliliters, and the mass is calculated by grams or the same proportion;

in the step S303, the concentration temperature is set to be 30-60 ℃.

Preferably, the pore diameter of the PTFE membrane is 0.22 μm; the mobile phase adopted by prep-HPLC comprises a mobile phase A and a mobile phase B, wherein the mobile phase A is a 0.1% formic acid acetonitrile solution, the mobile phase B is a 0.1% formic acid aqueous solution, and the flow rate is set to be 20 mL/min; the elution gradient is 0-6 min, and 18% -30% of mobile phase A; 30-42% of mobile phase A for 6-35 min; 35-45 min, 42-60% of mobile phase A; 45-50 min, 60-18% of mobile phase A; the injection volume is 650 mu L;

in the step S403, adding an anti-solvent ultrapure water, the volume of which is 3-7 times of the volume of the original solution, and crystallizing for more than 24 hours at the temperature of 1-10 ℃;

in step S404, the number of times of washing with deionized water is 3 or more.

The invention has the beneficial effects that: the method fully utilizes the citrus peel residues, not only prepares peel residue porous carbon, but also obtains 6 PMFs monomers from peel residue extracts, the purity of each PMFs monomer is over 95 percent, and the purity of the nobiletin reaches over 99 percent. The used solvent is safe, has no toxic or side effect, can be effectively recovered, has simple equipment and low energy consumption, and is suitable for large-scale production in factories.

Drawings

FIG. 1 is an SEM image of citrus pomace carbon prepared in example 3 of the present invention.

FIG. 2 is a skin X-ray diffraction pattern of citrus peel carbon obtained in example 3 of the present invention.

FIG. 3 is a Fourier infrared spectrum of citrus peel residue carbon prepared in example 3 of the present invention.

FIG. 4 is a Raman spectrum of the citrus peel residue carbon obtained in example 3 of the present invention.

FIG. 5 shows polymethoxylated flavone monomers prepared in examples 1 to 5 of the present invention.

FIG. 6 is a schematic diagram of polymethoxylated flavone monomer prepared in comparative example 1.

In fig. 5, the monomers listed are, from left to right: isosinensetin; sweet orange flavone; 5,6,7, 4' -tetramethoxyflavone; nobiletin; 5-hydroxy-desmethyl nobiletin; and (4) hesperetin.

In fig. 6, the monomers listed are, from left to right: sweet orange flavone; 5,6,7, 4' -tetramethoxyflavone; nobiletin; 5-hydroxy-desmethyl nobiletin; and (4) hesperetin.

Detailed Description

The invention is further illustrated by the following figures and examples.

The invention has 5 examples in total, and 5 examples which are not specifically described are prepared by the following steps. All the raw materials are not specifically described and are conventional commercial products.

In the following examples, the citrus peel residue is a brocade orange peel residue obtained by processing juice from Chongqing fresh fruit orange juice Co., Ltd (Chongqing Zhong), and is characterized by having a low PMFs content of less than 4.5mg/g DW.

S1: the preparation method of the citrus peel extract specifically comprises the following steps:

s101: the citrus peel residues are crushed to the particle size of 3-4 mm, an ethanol solution is added for soaking, the volume of the added ethanol solution is 5-8 times of the mass of the peel residues, and 1kg of citrus peel residues are used for preparing the extract in each embodiment of the application. In the present application, unless otherwise specified, the corresponding units of mass to volume ratio are respectively in grams and milliliters or adjusted in the same ratio, and the volume fraction of the ethanol solution is 70% to 90%. Soaking for 30-60 min to absorb water and soften the mixture, heating and refluxing for 2 times, refluxing and extracting at the temperature of 70-80 ℃ for 2-3 hours, filtering at normal pressure to obtain filtrate, combining the filtrate obtained twice, concentrating by adopting vacuum concentration, keeping the temperature of a concentration tank at 60-80 ℃, controlling the steam pressure at 0.01-0.05 MPa and controlling the vacuum degree at 0.055-0.085 MPa; recovering ethanol, discharging the concentrated solution, and concentrating to obtain the citrus peel extract, wherein the specific gravity of the concentrated solution is 1.1-1.35.