Emulsion with colon targeted delivery function as well as preparation method and application thereof

Abstract

The invention relates to an emulsion with a colon targeted delivery function as well as a preparation method and application thereof. The method comprises the following steps: S1, adding a cyclodextrin compound into a cationic cellulose nanocrystal suspension, and carrying out stirring self-assembly treatment to obtain a compound suspension; s2, dropwise adding an absolute ethyl alcohol solution of a flavonoid compound into the compound suspension, and sequentially carrying out stirring adsorption treatment and rotary evaporation treatment to obtain a mixture suspension; s3, adding a pectin compound into the mixture suspension, and stirring and mixing to obtain a wall material solution; and S4, mixing the oil phase with the wall material solution, and carrying out shearing treatment to obtain the emulsion with the targeted colon delivery function. The emulsion prepared by the method has relatively high capability of loading the flavonoid compounds, in-situ gel can be formed in the digestive tract, the flavonoid compounds can be delivered to the colon in a targeted manner, and the targeted delivery efficiency is relatively high.

Description

Technical Field

[0001] The present disclosure relates to the technical field of food additives and functional foods, and in particular, to an emulsion with colon-targeted delivery function, and a preparation method and application thereof. Background Art

[0002] As people's health awareness improves, the health benefits of fruits and vegetables to the human body are widely recognized. Plant secondary metabolites in fruits and vegetables are key components that exert biologically active functions and improve human functions. Among the many secondary metabolites, flavonoids have attracted widespread attention due to their significant health-promoting effects. Flavonoids include flavonoids, flavanones, flavonols, isoflavones, anthocyanins and proanthocyanidins. They have shown good intervention effects in anti-oxidation, anti-inflammatory, antibacterial, anti-cancer, and lipid metabolism regulation. In addition, epidemiological studies have shown that dietary flavonoids can significantly alleviate symptoms during acute attacks of inflammatory bowel disease and reduce chronic inflammatory states. Specifically, flavonoids help maintain the integrity of the intestinal barrier, prevent pharmacological damage to the intestinal wall, regulate intestinal microbiota and the immune system, and regulate intestinal hormone secretion through intestinal endocrine cells. Flavonoids are usually taken orally. The gastrointestinal tract is the core area that affects the absorption, distribution, metabolism and excretion of flavonoid compounds, which determines the delivery efficiency of flavonoids targeting the colon. Flavonoids are affected by many factors in the gastrointestinal tract, including the structure of the flavonoids themselves, the interaction with the food matrix, the activity of gastrointestinal hydrolases, and the transport efficiency of intestinal epithelial cells. After digestion in the gastrointestinal tract, flavonoids undergo significant structural modifications, and the biological activity of their decomposition products and metabolites is reduced, which is not conducive to the anti-inflammatory effect in the colon. In addition, most flavonoids have low solubility, are sensitive, and are easily decomposed. Especially in the high acid environment of the stomach, the structure of the flavonoids themselves is easily destroyed, and they cannot reach the colon target to exert their active effects.

[0003] In order to improve the efficiency of flavonoid colon delivery and improve the permeability of rectal mucosa to flavonoids, flavonoids are usually encapsulated in a carrier form and then delivered in vivo. Emulsion carrier system is the most common form of flavonoid encapsulation. During the encapsulation process, the carrier wall material acts as a physical barrier to effectively resist environmental stress and protect the biological activity of flavonoids. The viscoelastic gel-like emulsion composed of droplets as filling materials, which forms a three-dimensional network structure with long-chain polymer cross-linking, can further enhance this resistance. In addition, the emulsion has a short residence time in the colon and may reach the end of the colon, resulting in a first-pass effect; the formation of the gel-like emulsion requires additional addition of Ca 2+ The preparation method is complicated. Summary of the invention

[0004] The purpose of the present disclosure is to provide an emulsion with colon targeted delivery function and a preparation method thereof. The emulsion prepared by the method has a high ability to load flavonoid compounds and can form an in situ gel in the digestive tract, which is beneficial to the targeted delivery of flavonoid compounds to the colon, and the targeted delivery efficiency is high.

[0005] In order to achieve the above object, the present disclosure provides a first aspect of a method for preparing an emulsion with colon targeted delivery function, the method comprising the following steps: S1, adding a cyclodextrin compound to a cationic cellulose nanocrystal suspension for stirring and self-assembly treatment to obtain a composite suspension; S2, adding the anhydrous ethanol solution of flavonoid compounds dropwise to the composite suspension, performing stirring adsorption treatment and rotary evaporation treatment in sequence, to obtain a mixture suspension; S3, adding an aqueous solution of a pectin compound into the mixture suspension and stirring and mixing the mixture to obtain a wall material solution; S4, mixing the oil phase with the wall material solution and then performing shearing treatment to obtain an emulsion with colon-targeted delivery function.

[0006] Optionally, in step S1, in the cationic cellulose nanocrystal suspension, the mass fraction of the cationic cellulose nanocrystals is 0.02-0.40% by weight; The amount of the cyclodextrin compound added is 1.5-2.5 g per 100 mL of the cationic cellulose nanocrystal suspension; The conditions of the stirring self-assembly treatment include: temperature of 25-45°C, stirring rate of 200-450r / min, and time of 20-60min; The cyclodextrin compound is cyclodextrin and / or cyclodextrin derivatives, wherein the cyclodextrin is selected from one or more of α-cyclodextrin, β-cyclodextrin and λ-cyclodextrin; the cyclodextrin derivative is selected from one or more of hydroxyglucosyl-cyclodextrin, carboxymethyl-β-cyclodextrin and 2-hydroxypropyl-β-cyclodextrin.

[0007] Optionally, in step S2, the mass concentration of the anhydrous ethanol solution of the flavonoid compound is 1-10 mg / mL; The drop rate of the anhydrous ethanol solution of the flavonoid compound is 1-3 drops / second; in the mixture suspension, the mass fraction of the flavonoid compound is 0.1-0.5 mg / mL; The stirring adsorption treatment conditions include: temperature of 25-45°C, stirring rate of 200-450r / min, and time of 1-10min; The conditions of the rotary evaporation treatment include: temperature of 30-45°C and time of 5-10 minutes; The flavonoid compound is selected from naringenin and / or quercetin.

[0008] Optionally, in the wall material solution, the mass concentration of the pectin compound is 1.5-40 mg / mL; The stirring and mixing treatment conditions include: temperature of 25-45°C, stirring rate of 200-450r / min, and time of 3-24h; The pectin compound is low-ester pectin, and the esterification degree of the low-ester pectin is less than 30%; wherein the low-ester pectin is selected from one or more of citrus pectin, apple pectin and beet pectin.

[0009] Optionally, the amount of the oil phase added is 1.0-12.0 g, preferably 5.0-10.0 g, per 100 mL of the wall material solution; Wherein, the oil phase is selected from one or more of medium chain triglycerides, peanut oil, soybean oil, olive oil, rice bran oil, rapeseed oil and linseed oil; The shearing treatment conditions include: a shearing speed of 8000-12000 rpm / min; and a shearing time of 2-5 min.

[0010] The second aspect of the present disclosure provides an emulsion with colon targeted delivery function prepared by the preparation method described in the first aspect.

[0011] Optionally, the emulsion contains an aqueous phase and an oil phase; The aqueous phase contains cyclodextrin compounds, cationic cellulose nanocrystals, flavonoid compounds and pectin compounds; The oil phase is selected from one or more of medium chain triglycerides, peanut oil, soybean oil, olive oil, rice bran oil, rapeseed oil and linseed oil.

[0012] Optionally, based on the total weight of the aqueous phase, the content of the cyclodextrin compounds is 1.5-2.5% by weight, the content of the cationic cellulose nanocrystals is 0.02-0.40% by weight, the content of the flavonoid compounds is 0.1-0.5% by weight, and the content of the pectin compounds is 0.5-4.0% by weight.

[0013] Optionally, based on the total weight of the emulsion, the content of the water phase is 90.0-99.0% by weight, and the content of the oil phase is 1.0-10.0% by weight.

[0014] Optionally, the cyclodextrin compound is cyclodextrin and / or cyclodextrin derivatives, wherein the cyclodextrin is selected from one or more of α-cyclodextrin, β-cyclodextrin and λ-cyclodextrin; the cyclodextrin derivative is selected from one or more of hydroxyglucosyl-cyclodextrin, carboxymethyl-β-cyclodextrin and 2-hydroxypropyl-β-cyclodextrin; The flavonoid compound is selected from naringenin and / or quercetin; The pectin compound is low-ester pectin, and the esterification degree of the low-ester pectin is less than 30%; wherein the low-ester pectin is selected from one or more of citrus pectin, apple pectin and beet pectin.

[0015] The third aspect of the present disclosure provides a use of the emulsion of the first aspect in preparing a functional product for targeted delivery of flavonoid compounds to the colon; wherein the functional product is selected from food or medicine; The flavonoid compound is selected from naringenin and / or quercetin.

[0016] Through the above technical scheme, in the emulsion prepared by the present invention, the special hydrophobic cavity of the cyclodextrin compound can significantly increase the loading efficiency and loading amount of the flavonoid compound. Cationic cellulose nanocrystals can improve the emulsification effect of the emulsion of the present invention. The present invention also adds pectin compounds when preparing the emulsion. Under the joint action of low-ester pectin and the complex, the emulsion can form an emulsion gel in situ under the acid environment in the stomach, effectively improving the stability of the emulsion prepared by the present invention and the flavonoid targeted colon delivery effect. The emulsion of the present invention can resist environmental stress during gastrointestinal digestion, and further ensure the delivery efficiency of flavonoid compounds targeted to the colon.

[0017] Other features and advantages of the present disclosure will be described in detail in the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The accompanying drawings are used to provide a further understanding of the present disclosure and constitute a part of the specification. Together with the following specific embodiments, they are used to explain the present disclosure but do not constitute a limitation of the present disclosure. In the accompanying drawings: Figure 1 The appearance of the suspension of flavonoid-loaded cyclodextrin / cationic cellulose nanocrystal complex.

[0019] Figure 2 is the embedding rate and loading rate of flavonoids.

[0020] Figure 3 Characterization of cyclodextrin / cationic cellulose nanocrystal composites loaded with flavonoids.

[0021] Figure 4 The stability of the emulsion gel system prepared in the examples and comparative examples of the present disclosure in gastric digestive juice.

[0022] Figure 5 The release rate of flavonoids in the colon of the emulsion gel system prepared in the examples and comparative examples of the present disclosure. DETAILED DESCRIPTION

[0023] The specific implementation of the present disclosure is described in detail below in conjunction with the accompanying drawings. It should be understood that the specific implementation described herein is only used to illustrate and explain the present disclosure, and is not used to limit the present disclosure.

[0024] The first aspect of the present disclosure provides a method for preparing an emulsion with colon targeted delivery function, the method comprising the following steps: S1, adding a cyclodextrin compound to a cationic cellulose nanocrystal suspension for stirring and self-assembly treatment to obtain a composite suspension; S2, adding the anhydrous ethanol solution of flavonoid compounds dropwise to the composite suspension, performing stirring adsorption treatment and rotary evaporation treatment in sequence, to obtain a mixture suspension; S3, adding pectin compounds to the mixture suspension and stirring and mixing them to obtain a wall material solution; S4, mixing the oil phase with the wall material solution and then performing shearing treatment to obtain an emulsion with colon-targeted delivery function.

[0025] In the present disclosure, cyclodextrin compounds and cationic cellulose nanocrystals form a complex through hydrogen bonds or electrostatic interactions; wherein the special hydrophobic cavities of cyclodextrin compounds can significantly increase the loading efficiency and loading amount of flavonoid compounds. Cationic cellulose nanocrystals can improve the emulsification effect of the emulsion of the present disclosure. The present disclosure also adds low-ester pectin when preparing the emulsion. Under the joint action of low-ester pectin and cyclodextrin and cationic cellulose nanocrystal complexes, the emulsion can form an emulsion gel in situ under the gastric environment. The emulsion gel will adhere to the colon to avoid the first-pass effect, which is beneficial for the flavonoid active substances to play a role in the colon, thereby effectively improving the stability of the emulsion prepared by the present disclosure and the flavonoid targeted colon delivery effect. There are a certain number of salt ions and H in the human digestive tract environment. + , using the ionic and acidic environment of the human digestive tract to transform the emulsion into a gel-like emulsion is of great significance for the targeted delivery of flavonoids to the colon. The emulsion disclosed in the present invention can resist the environmental stress during gastrointestinal digestion, further ensuring the delivery efficiency of flavonoids to the colon.

[0026] In one embodiment of the present disclosure, in step S1, in the cationic cellulose nanocrystal suspension, the mass fraction of the cationic cellulose nanocrystal is 0.02-0.40% by weight; and the amount of the cyclodextrin compound added is 1.5-2.5 mg per 100 mL of the cationic cellulose nanocrystal suspension. In the above embodiment, it is more conducive to the combination of cyclodextrin compounds and cellulose nanocrystals, and the solubility of the two is basically saturated at the specified maximum addition amount, thereby achieving the highest emulsification effect.

[0027] In one embodiment of the present disclosure, the stirring self-assembly treatment conditions include: a temperature of 25-45°C, a stirring rate of 200-450r / min, and a time of 20-60min. The stirring self-assembly treatment can be performed using instruments conventionally used by those skilled in the art, such as a magnetic stirrer. Infrared spectroscopy can be used to verify the complex formed by the combination of cyclodextrin compounds and cationic cellulose nanocrystals after self-assembly.

[0028] In the present disclosure, the cyclodextrin compound may be cyclodextrin and / or cyclodextrin derivatives, wherein the cyclodextrin is selected from one or more of α-cyclodextrin, β-cyclodextrin and λ-cyclodextrin; and the cyclodextrin derivative is selected from one or more of hydroxyglucosyl-cyclodextrin, carboxymethyl-β-cyclodextrin and 2-hydroxypropyl-β-cyclodextrin. β-cyclodextrin is preferred.

[0029] In one embodiment of the present disclosure, in step S2, the mass concentration of the anhydrous ethanol solution of flavonoid compounds is 1-10 mg / mL; the dripping rate of the anhydrous ethanol solution of flavonoid compounds is 1-3 drops / second.

[0030] In the present disclosure, the encapsulation efficiency can be improved by dripping the anhydrous ethanol solution of flavonoid compounds into the composite suspension, especially when the dripping rate is 1-2 drops / second to achieve the highest encapsulation effect.

[0031] In one embodiment of the present disclosure, in the mixture suspension, the mass fraction of the flavonoid compound is 0.1-0.5 mg / mL. In the above embodiment, the highest loading rate can be achieved while ensuring that the complex is dispersed and not aggregated.

[0032] In one embodiment of the present disclosure, the conditions of the stirring adsorption treatment include: temperature of 25-45°C, stirring rate of 200-450r / min, and time of 1-10min; the conditions of the rotary evaporation treatment include: temperature of 30-45°C, and time of 5-10min. The stirring adsorption treatment can be performed using instruments conventionally used by those skilled in the art, such as a magnetic stirrer. The rotary evaporation treatment can be performed using instruments conventionally used by those skilled in the art, such as a rotary evaporator.

[0033] In one embodiment of the present disclosure, the flavonoid compound is selected from naringenin and / or quercetin. Among them, naringenin and quercetin have a relatively low molecular weight and can be encapsulated into the cyclodextrin cavity.

[0034] In one embodiment of the present disclosure, in the wall material solution, the mass concentration of the pectin compound is 1.5-40 mg / mL. In the above embodiment, the use of pectin can further improve the emulsification effect of the emulsion.

[0035] In one embodiment of the present disclosure, the stirring and mixing treatment conditions include: temperature of 25-45°C, stirring rate of 200-450r / min, and time of 20-60min. The stirring and mixing treatment can be performed using instruments conventionally used by those skilled in the art, such as a magnetic stirrer.

[0036] In a preferred embodiment of the present disclosure, the pectin compound is low-ester pectin, and the esterification degree of the low-ester pectin is less than 30%. The low-ester pectin is selected from one or more of citrus pectin, apple pectin and beet pectin.

[0037] In one embodiment of the present disclosure, the amount of the oil phase added is 1.0-12.0 g, preferably 5.0-10.0 g, per 100 mL of the wall material solution. The oil phase is selected from one or more of medium chain triglycerides, peanut oil, soybean oil, olive oil, rice bran oil, rapeseed oil and linseed oil; In one embodiment of the present disclosure, the shear treatment conditions include: a shear speed of 8000-12000 rpm / min, preferably 10000-11000 rpm / min; and a time of 2-5 min, preferably 3-5 min.

[0038] The second aspect of the present disclosure provides an emulsion with colon targeted delivery function prepared by the preparation method described in the first aspect.

[0039] In the present disclosure, the emulsion with colon-targeted delivery function can form an emulsion gel in situ under the environment of the stomach, resist environmental stress during gastrointestinal digestion, and further ensure the delivery efficiency of flavonoid compounds targeted to the colon.

[0040] According to the present disclosure, the emulsion contains an aqueous phase and an oil phase, wherein the aqueous phase contains cyclodextrin compounds, cationic cellulose nanocrystals, flavonoid compounds and pectin compounds; the oil phase is selected from one or more of medium-chain triglycerides, peanut oil, soybean oil, olive oil, rice bran oil, rapeseed oil and linseed oil.

[0041] In one embodiment of the present disclosure, based on the total weight of the aqueous phase, the content of the cyclodextrin compounds is 1.5-2.5% by weight, the content of the cationic cellulose nanocrystals is 0.02-0.40% by weight, the content of the flavonoid compounds is 0.1-1.5% by weight, and the content of the pectin compounds is 0.5-4.0% by weight.

[0042] In one embodiment of the present disclosure, based on the total weight of the emulsion, the content of the water phase is 90.0-99.0% by weight, and the content of the oil phase is 1.0-10.0% by weight.

[0043] In one embodiment of the present disclosure, the cyclodextrin compound is cyclodextrin and / or cyclodextrin derivatives, the cyclodextrin is selected from one or more of α-cyclodextrin, β-cyclodextrin and λ-cyclodextrin; the cyclodextrin derivative is selected from one or more of hydroxyglucosyl-cyclodextrin, carboxymethyl-β-cyclodextrin and 2-hydroxypropyl-β-cyclodextrin; the flavonoid compound is selected from naringenin and / or quercetin; the pectin compound is low-ester pectin, and the esterification degree of the low-ester pectin is less than 30%; wherein the low-ester pectin is selected from one or more of citrus pectin, apple pectin and beet pectin.

[0044] The third aspect of the present disclosure provides a use of the emulsion of the first aspect in preparing a functional product for targeted delivery of flavonoid compounds to the colon; wherein the functional product is selected from food or medicine; The flavonoid compound is selected from naringenin and / or quercetin.

[0045] The present disclosure is further illustrated below by way of examples, but the present disclosure is not limited thereby.

[0046] In the following examples, unless otherwise specified, the raw materials and reagents used are commercially available products.

[0047] Unless otherwise specified, the experimental methods used in the following examples are conventional methods.

[0048] The quantitative tests in the following examples were all repeated three times, and the results were averaged.

[0049] The MCT, cyclodextrin (analytical grade) and pectin used in the following examples were purchased from Beijing Solebow Technology Co., Ltd., and the cellulose nanocrystals (analytical grade) were purchased from Zhejiang ScienceK Technology Co., Ltd.

[0050] Example 1 S1. Add 1.5 g of β-cyclodextrin to 100 mL of cationic cellulose nanocrystal suspension (0.25 wt %), and stir for self-assembly at 45° C. and 450 r / min for 60 min to obtain a composite suspension; S2, adding 2 mL of 10 mg / mL anhydrous ethanol solution of naringenin to 100 mL of the composite suspension at a rate of 1 drop / second, stirring and adsorbing for 10 min at 25°C and 250 r / min, and then performing a rotary evaporation treatment at 30°C for 5 min to remove ethanol, to obtain a mixture suspension; S3, adding 2.5 mg of citrus pectin (esterification degree of 25%) to 100 mL of the mixture suspension, stirring and mixing at 25° C. and 450 r / min for 12 h to obtain a wall material solution; S4. After mixing 10 g of MCT (medium chain triglycerides, as the oil phase) with 90 mL of the wall material solution, the mixture was sheared at a high speed of 11,000 r / min for 5 min to obtain an emulsion S-1 with a targeted colon delivery function.

[0051] In emulsion S-1, based on the total weight of the aqueous phase, the content of β-cyclodextrin was 1.5% by weight, the content of cationic cellulose nanocrystals was 0.25% by weight, and the content of naringenin was 0.2% by weight; based on the total weight of the emulsion, the content of the oil phase was 10% by weight, the content of the aqueous phase was 90% by weight, and the content of low-ester pectin was 2.5% by weight.

[0052] Example 2 S1. Add 2 g of β-cyclodextrin to 100 mL of cationic cellulose nanocrystal suspension (0.25 wt %), and stir for self-assembly at 45° C. and 450 r / min for 60 min to obtain a composite suspension; S2, adding 6 mL of 5 mg / mL quercetin anhydrous ethanol solution to 100 mL of the complex suspension at a rate of 1 drop / second, stirring and adsorbing for 10 min at 25°C and 250 r / min, and then performing a rotary evaporation treatment at 30°C for 5 min to remove ethanol, to obtain a mixture suspension; S3, adding 2.5 mg of citrus pectin (esterification degree of 25%) to 100 mL of the mixture suspension, stirring and mixing at 25° C. and 450 r / min for 12 h to obtain a wall material solution; S4. After mixing 10 g of MCT (medium chain triglycerides, as the oil phase) with 90 mL of the wall material solution, the mixture was sheared at a high speed of 11,000 r / min for 5 min to obtain an emulsion S-2 with a colon-targeted delivery function.

[0053] In emulsion S-1 and in emulsion S-2, based on the total weight of the aqueous phase, the content of β-cyclodextrin was 2 weight%, the content of cationic cellulose nanocrystals was 0.25 weight%, and the content of quercetin was 0.3 weight%; based on the total weight of the emulsion, the content of the oil phase was 10 weight%, the content of the aqueous phase was 90 weight%, and the content of low-ester pectin was 2.5 weight%.

[0054] Example 3 S1, adding 2.5 g of β-cyclodextrin to 100 mL of cationic cellulose nanocrystal suspension (0.25 wt %), stirring and self-assembly treating at 45° C. and 450 r / min for 60 min to obtain a composite suspension; S2, adding 3 mL of 10 mg / mL anhydrous ethanol solution of naringenin to 100 mL of the composite suspension at a rate of 1 drop / second, stirring and adsorbing for 10 min at 25°C and 250 r / min, and then performing a rotary evaporation treatment at 30°C for 5 min to remove ethanol, to obtain a mixture suspension; S3, adding 1.5 mg of citrus pectin (esterification degree of 25%) to 100 mL of the mixture suspension, stirring and mixing at 25° C. and 450 r / min for 12 h to obtain a wall material solution; S4. After mixing 10 g of MCT (medium chain triglycerides, as the oil phase) with 90 mL of the wall material solution, the mixture was sheared at a high speed of 11,000 r / min for 5 min to obtain an emulsion S-3 with a colon-targeted delivery function.

[0055] In emulsion S-3, based on the total weight of the aqueous phase, the content of β-cyclodextrin was 2.5% by weight, the content of cationic cellulose nanocrystals was 0.25% by weight, and the content of naringenin was 0.3% by weight; based on the total weight of the emulsion, the content of the oil phase was 10% by weight, the content of the aqueous phase was 90% by weight, and the content of low-ester pectin was 1.5% by weight.

[0056] Example 4 S1, adding 2.5 g of β-cyclodextrin to 100 mL of cationic cellulose nanocrystal suspension (0.25 wt %), stirring and self-assembly treating at 45° C. and 450 r / min for 60 min to obtain a composite suspension; S2, adding 3 mL of 10 mg / mL anhydrous ethanol solution of naringenin to 100 mL of the composite suspension at a rate of 1 drop / second, stirring and adsorbing for 10 min at 25°C and 250 r / min, and then performing a rotary evaporation treatment at 30°C for 5 min to remove ethanol, to obtain a mixture suspension; S3, adding 2 mg of citrus pectin (esterification degree of 25%) to 100 mL of the mixture suspension, stirring and mixing at 25° C. and 450 r / min for 12 h to obtain a wall material solution; S4, after mixing 10 g of MCT (medium chain triglyceride, as the oil phase) with 90 mL of the wall material solution, high-speed shearing was performed at a rotation speed of 11000 r / min for 5 minutes to obtain an emulsion S-4 with a targeted colon delivery function.

[0057] In emulsion S-4, based on the total weight of the aqueous phase, the content of β-cyclodextrin was 2.5% by weight, the content of cationic cellulose nanocrystals was 0.25% by weight, and the content of naringenin was 0.3% by weight; based on the total weight of the emulsion, the content of the oil phase was 10% by weight, the content of the aqueous phase was 90% by weight, and the content of the low-ester pectin was 2% by weight.

[0058] Example 5 S1, adding 2.5 g of β-cyclodextrin to 100 mL of cationic cellulose nanocrystal suspension (0.25 wt %), stirring and self-assembly treating at 45° C. and 450 r / min for 60 min to obtain a composite suspension; S2, adding 3 mL of 10 mg / mL anhydrous ethanol solution of naringenin to 100 mL of the composite suspension at a rate of 1 drop / second, stirring and adsorbing for 10 min at 25°C and 250 r / min, and then performing a rotary evaporation treatment at 30°C for 5 min to remove ethanol, to obtain a mixture suspension; S3, adding 2.5 mg of citrus pectin (esterification degree of 25%) to 100 mL of the mixture suspension, stirring and mixing at 25° C. and 450 r / min for 12 h to obtain a wall material solution; S4. After mixing 10 g of MCT (medium chain triglycerides, as the oil phase) with 90 mL of the wall material solution, the mixture was sheared at a high speed of 11,000 r / min for 5 min to obtain an emulsion S-5 with a colon-targeted delivery function.

[0059] In emulsion S-5, based on the total weight of the aqueous phase, the content of β-cyclodextrin was 2.5% by weight, the content of cationic cellulose nanocrystals was 0.25% by weight, and the content of naringenin was 0.3% by weight; based on the total weight of the emulsion, the content of the oil phase was 10% by weight, the content of the aqueous phase was 90% by weight, and the content of low-ester pectin was 2.5% by weight.

[0060] Example 6 S1, adding 2.5 g of β-cyclodextrin to 100 mL of cationic cellulose nanocrystal suspension (0.25 wt %), stirring and self-assembly treating at 45° C. and 450 r / min for 60 min to obtain a composite suspension; S2, adding 3 mL of 10 mg / mL quercetin anhydrous ethanol solution to 100 mL of the complex suspension at a rate of 1 drop / second, stirring and adsorbing for 10 min at 25°C and 250 r / min, and then performing a rotary evaporation treatment at 30°C for 5 min to remove ethanol, to obtain a mixture suspension; S3, adding 3 mg of citrus pectin (esterification degree of 25%) to 100 mL of the mixture suspension, stirring and mixing at 25° C. and 450 r / min for 12 h to obtain a wall material solution; S4. After mixing 10 g of MCT (medium chain triglycerides, as the oil phase) with 90 mL of the wall material solution, the mixture was sheared at a high speed of 11,000 r / min for 5 min to obtain an emulsion S-6 with a colon-targeted delivery function.

[0061] In emulsion S-6, based on the total weight of the aqueous phase, the content of β-cyclodextrin was 2.5% by weight, the content of cationic cellulose nanocrystals was 0.25% by weight, and the content of quercetin was 0.3% by weight; based on the total weight of the emulsion, the content of the oil phase was 10% by weight, the content of the aqueous phase was 90% by weight, and the content of low-ester pectin was 3% by weight.

[0062] Comparative Example 1 S1, adding 2.5 g of β-cyclodextrin to 100 mL of cationic cellulose nanocrystal suspension (0.25 wt %), stirring and self-assembly treating at 45° C. and 450 r / min for 60 min to obtain a composite suspension; S2, adding 2 mL of anhydrous ethanol solution of 10 mg / mL hesperidin to 100 mL of the composite suspension at a rate of 1 drop / second, stirring and adsorbing for 10 min at 25° C. and 250 r / min, and then performing a rotary evaporation treatment at 30° C. for 5 min to remove ethanol, to obtain a mixture suspension; S3, adding 2.5 mg of citrus pectin (esterification degree of 25%) to 100 mL of the mixture suspension, stirring and mixing at 25° C. and 450 r / min for 12 h to obtain a wall material solution; S4. After mixing 10 g of MCT (medium chain triglyceride, as the oil phase) with 90 mL of the wall material solution, the mixture was sheared at a high speed of 11000 r / min for 5 min to obtain emulsion D-1.

[0063] In emulsion D-1, based on the total weight of the aqueous phase, the content of β-cyclodextrin was 2.5% by weight, the content of cationic cellulose nanocrystals was 0.25% by weight, and the content of hesperidin was 0.2% by weight; based on the total weight of the emulsion, the content of the oil phase was 10% by weight, the content of the aqueous phase was 90% by weight, and the content of low-ester pectin was 2.5% by weight.

[0064] Comparative Example 2 S1, adding 2.5 g of β-cyclodextrin to 100 mL of cationic cellulose nanocrystal suspension (0.25 wt %), stirring and self-assembly treating at 45° C. and 450 r / min for 60 min to obtain a composite suspension; S2, adding 2 mL of anhydrous ethanol solution of 10 mg / mL neohesperidin to 100 mL of the composite suspension at a rate of 1 drop / second, stirring and adsorbing for 10 min at 25°C and 250 r / min, and then performing a rotary evaporation treatment at 30°C for 5 min to remove ethanol, to obtain a mixture suspension; S3, adding 2.5 mg of citrus pectin (esterification degree of 25%) to 100 mL of the mixture suspension, stirring and mixing at 25°C and 450 r / min for 12 h to obtain a wall material solution; S4. After mixing 10 g of MCT (medium chain triglyceride, as the oil phase) with 90 mL of the wall material solution, the mixture was sheared at a high speed of 11000 r / min for 5 min to obtain emulsion D-2.

[0065] In emulsion D-2, based on the total weight of the aqueous phase, the content of β-cyclodextrin was 2.5% by weight, the content of cationic cellulose nanocrystals was 0.25% by weight, and the content of neohesperidin was 0.2% by weight; based on the total weight of the emulsion, the content of the oil phase was 10% by weight, the content of the aqueous phase was 90% by weight, and the content of low-ester pectin was 2.5% by weight.

[0066] Comparative Example 3 S1, adding 2.5 g of β-cyclodextrin to 100 mL of cationic cellulose nanocrystal suspension (0.25 wt %), stirring and self-assembly treating at 45° C. and 450 r / min for 60 min to obtain a composite suspension; S2, adding 2 mL of 10 mg / mL anhydrous ethanol solution of naringin to 100 mL of the composite suspension at a rate of 1 drop / second, stirring and adsorbing for 10 min at 25° C. and 250 r / min, and then performing a rotary evaporation treatment at 30° C. for 5 min to remove ethanol, to obtain a mixture suspension; S3, adding 2.5 mg of citrus pectin (esterification degree of 25%) to 100 mL of the mixture suspension, stirring and mixing at 25°C and 450 r / min for 12 h to obtain a wall material solution; S4. After mixing 10 g of MCT (medium chain triglyceride, as the oil phase) with 90 mL of the wall material solution, the mixture was sheared at a high speed of 11000 r / min for 5 min to obtain emulsion D-3.

[0067] In emulsion D-3, based on the total weight of the aqueous phase, the content of β-cyclodextrin was 2.5% by weight, the content of cationic cellulose nanocrystals was 0.25% by weight, and the content of naringin was 0.2% by weight; based on the total weight of the emulsion, the content of the oil phase was 10% by weight, the content of the aqueous phase was 90% by weight, and the content of low-ester pectin was 2.5% by weight.

[0068] Comparative Example 4 S1, adding 2.5 g of β-cyclodextrin to 100 mL of cationic cellulose nanocrystal suspension (0.25 wt %), stirring and self-assembly treating at 45° C. and 450 r / min for 60 min to obtain a composite suspension; S2, adding 2 mL of 10 mg / mL anhydrous ethanol solution of naringin to 100 mL of the composite suspension at a rate of 1 drop / second, stirring and adsorbing for 10 min at 25° C. and 250 r / min, and then performing a rotary evaporation treatment at 30° C. for 5 min to remove ethanol, to obtain a mixture suspension; S3, adding 2.5 mg of high-ester citrus pectin (esterification degree of 60%) to 100 mL of the mixture suspension, stirring and mixing at 25° C. and 450 r / min for 12 h to obtain a wall material solution; S4. After mixing 10 g of MCT (medium chain triglyceride, as the oil phase) with 90 mL of the wall material solution, the mixture was sheared at a high speed of 11000 r / min for 5 min to obtain emulsion D-4.

[0069] In emulsion D-4, based on the total weight of the aqueous phase, the content of β-cyclodextrin was 2.5% by weight, and the content of cationic cellulose nanocrystals was 0.25% by weight; based on the total weight of the emulsion, the content of the oil phase was 10% by weight, the content of the aqueous phase was 90% by weight, the content of naringenin was 0.09% by weight, and the content of high-ester pectin was 2.5% by weight.

[0070] Comparative Example 5 S1, adding 2.5 g of β-cyclodextrin to 100 mL of cationic cellulose nanocrystal suspension (0.25 wt %), stirring and self-assembly treating at 45° C. and 450 r / min for 60 min to obtain a composite suspension; S2, adding 2 mL of 10 mg / mL anhydrous ethanol solution of naringin to 100 mL of the composite suspension at a rate of 1 drop / second, stirring and adsorbing for 10 min at 25°C and 250 r / min, and then performing rotary evaporation at 30°C for 5 min to remove ethanol to obtain a mixture suspension; this system is used as the wall material solution; S3. After mixing 10 g of MCT (medium chain triglyceride, as the oil phase) with 90 mL of the wall material solution, the mixture was sheared at a high speed of 11000 r / min for 5 min to obtain emulsion D-5.

[0071] In emulsion D-5, based on the total weight of the aqueous phase, the content of β-cyclodextrin was 2.5% by weight, the content of cationic cellulose nanocrystals was 0.25% by weight, and the content of naringenin was 0.2% by weight; based on the total weight of the emulsion, the content of the oil phase was 10% by weight, and the content of the aqueous phase was 90% by weight.

[0072] Comparative Example 6 S1, adding 2.5 g of β-cyclodextrin to 100 mL of cationic cellulose nanocrystal suspension (0.25 wt %), stirring and self-assembly treating at 45° C. and 450 r / min for 60 min to obtain a composite suspension; S2, adding 2 mL of 10 mg / mL anhydrous ethanol solution of naringenin to 100 mL of the composite suspension at a rate of 1 drop / second, stirring and adsorbing for 10 min at 25°C and 250 r / min, and then performing a rotary evaporation treatment at 30°C for 5 min to remove ethanol, to obtain a mixture suspension; S3, adding 0.5 mg of citrus pectin (esterification degree of 25%) to 100 mL of the mixture suspension, stirring and mixing at 25° C. and 450 r / min for 12 h to obtain a wall material solution; S4. After mixing 10 g of MCT (medium chain triglyceride, as the oil phase) with 90 mL of the wall material solution, the mixture was sheared at a high speed of 11000 r / min for 5 min to obtain emulsion D-6.

[0073] In emulsion D-6, based on the total weight of the aqueous phase, the content of β-cyclodextrin was 2.5% by weight, the content of cationic cellulose nanocrystals was 0.25% by weight, and the content of naringenin was 0.2% by weight; based on the total weight of the emulsion, the content of the oil phase was 10% by weight, the content of the aqueous phase was 90% by weight, and the content of low-ester pectin was 0.5% by weight.

[0074] Comparative Example 7 S1. Dissolve 2.8 g of citrus pectin (esterification degree of 25%) in deionized water and adjust the volume to 100 mL. Stir and mix at 25°C and 450 r / min for 12 h. Add 2 mL of 10 mg / mL anhydrous ethanol solution of naringenin to the pectin solution. Rotary evaporate at 30°C for 5 min to remove ethanol to obtain a wall material solution. S2. After mixing 10 g of MCT (medium chain triglyceride, as the oil phase) with 90 mL of the wall material solution, the mixture was sheared at a high speed of 11000 r / min for 5 min to obtain emulsion D-6.

[0075] In emulsion D-7, based on the total weight of the aqueous phase, the content of naringenin was 0.2 wt %, based on the total weight of the emulsion, the content of the oil phase was 10 wt %, the content of the aqueous phase was 90 wt %, and the content of the low-ester pectin was 2.5 wt %.

[0076] Test Example 1 This test example is used to illustrate the successful preparation and high bioavailability characterization of the flavonoid emulsion disclosed in the present invention.

[0077] (1) Observation of the apparent turbidity of the composite suspension: Take 10 mL of the freshly prepared composite suspension and put it into a 20 mL transparent glass bottle. Use a digital camera to record the apparent turbidity of the suspension. The results are as follows: Figure 1 shown.

[0078] (2) Encapsulation efficiency and loading rate of flavonoid compounds: The complex suspension was centrifuged at 10,000 rpm for 10 min to separate the supernatant containing free flavonoids that were not encapsulated. The supernatant was diluted with anhydrous ethanol in an appropriate proportion and the absorbance of the supernatant was measured using a UV-visible spectrophotometer. The encapsulation efficiency (EE, %) and loading capacity (LC, %) were calculated using the following formula:

[0079] Where m is the mass of free flavonoids (mg); m0 is the original mass of added flavonoids (mg); i is the mass of β-cyclodextrin / cationic cellulose nanocrystal composite (mg).

[0080] The embedding and loading rates of flavonoids are as follows Figure 2 shown.

[0081] (3) Fourier transform infrared (FTIR): The β-CD / CNC complex, CD / CNC complex loaded with naringenin / quercetin, and the mixture of naringenin / quercetin and β-CD / CNC complex were scanned by FTIR. The sample and KBr were thoroughly ground and mixed in a mortar at a mass ratio of 1:100. After tableting, the samples were observed at 4000 to 400 cm -1 The scan was performed within the wave number range of 64, with a resolution of 4 cm -1 The results are as follows Figure 3 shown.

[0082] (4) Observation of apparent stability of flavonoid emulsion: 10 mL of freshly prepared emulsion was placed in a 20 mL transparent glass bottle, and the pH value was adjusted to 2.5 with 0.5 M HCl. A digital camera was used to record the stratification of the emulsion after standing for 24 h. The results are shown in the figure. Figure 4 shown.

[0083] (5) Determination of the release rate of flavonoid compounds: The present invention uses an in vitro simulated gastrointestinal tract (GIT) technology to study the release rate of flavonoids in the above-mentioned embodiment and comparative example emulsions. The samples digested in the mouth, stomach, small intestine and colon were mixed with 4 volumes of anhydrous ethanol and vortexed for 5 minutes to fully extract the flavonoids. After the digested samples were centrifuged (9000rpm, 20min), the absorbance values ​​of flavonoids (naringenin 290nm, quercetin 373nm) were measured by UV-visible spectrophotometer, and the release rate (%) of flavonoids was calculated by the following formula:

[0084] Where M initial and M final They represent the total amount of flavonoids after digestion (mg) and the total amount of flavonoids added (mg), respectively.

[0085] The release rate of flavonoids from the emulsion gel system after simulated colon digestion is as follows Figure 5 shown.

[0086] Depend on Figure 1It can be seen that the composite suspensions prepared in Examples 1 and 2 become turbid, while Comparative Examples 1-3 remain clear and transparent. This indicates that naringenin and quercetin can combine with the β-cyclodextrin / cationic fiber nanocrystal composite to form particles with larger particle size. However, hesperidin, neohesperidin and naringin are not loaded by the β-cyclodextrin / cationic fiber nanocrystal composite after addition, and slow precipitation occurs, and the solution does not change.

[0087] Depend on Figure 2 It can be seen that the embedding rates of Examples 1 and 2 are both over 90%, and the loading rate is also maintained at a relatively high level. The embedding rates of Comparative Examples 1-3 are 25.73%, 20.75%, and 10.89%, respectively, which are significantly lower. This indicates that the flavonoids loaded by the β-cyclodextrin / cationic fiber nanocrystal composite are specific, and only exhibit high loading efficiency for naringenin and quercetin, while the loading rates for other flavonoids such as hesperidin, neohesperidin, and naringin are relatively low.

[0088] Depend on Figure 3 It can be seen that the functional groups of naringenin and quercetin have typical characteristic peaks. After naringenin and quercetin are encapsulated in the β-cyclodextrin / cationic fiber nanocrystal complex, their infrared spectra are highly similar to the β-cyclodextrin / cationic fiber nanocrystal complex, which indicates that the cavity of β-cyclodextrin masks the characteristic peaks of naringenin and quercetin, and naringenin and quercetin are embedded in the complex rather than directly adsorbed on the surface of the complex.

[0089] Verify whether the emulsion can form an emulsion gel in situ under the gastric environment. Figure 4 It can be seen that comparative examples 5 and 6 are stratified, comparative example 4 remains stable, but no gel structure is formed, and comparative example 7 forms a weak gel, but the strength is low. This shows that emulsion gel cannot be formed without adding low-ester pectin or the pectin concentration is too low. The gelling conditions of high-ester pectin generally require high sugar and high acid. Only adjusting the pH cannot form an emulsion gel. Only using a single low-ester pectin with naringenin and MCT compounding cannot form a high-strength emulsion gel. The stability of Examples 3-6 gradually increases, especially Examples 4-6 form a stable viscoelastic emulsion gel structure. This shows that low-ester pectin with an esterification degree of less than 30% not only helps to improve the stability of the emulsion, but also when the concentration reaches 2% and above, the complex and low-ester pectin can form a stable emulsion gel in the stomach.

[0090] Depend on Figure 5 It can be seen that the flavonoid release rates of Comparative Examples 4-7 are 10.33%, 4.44%, 7.39% and 19.88%, respectively. The flavonoid release rates of Examples 1-6 are significantly increased, greater than 20%, and up to 40.53%. This indicates that the emulsion gel system prepared in the present application has a high flavonoid retention rate, which is beneficial for flavonoids to target the colon and thus exert their active efficacy.

[0091] The preferred embodiments of the present disclosure are described in detail above in conjunction with the accompanying drawings; however, the present disclosure is not limited to the specific details in the above embodiments. Within the technical concept of the present disclosure, a variety of simple modifications can be made to the technical solution of the present disclosure, and these simple modifications all fall within the protection scope of the present disclosure.

[0092] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present disclosure will not further describe various possible combinations.

[0093] In addition, various embodiments of the present disclosure may be arbitrarily combined, and as long as they do not violate the concept of the present disclosure, they should also be regarded as the contents disclosed by the present disclosure.

Claims

1. A method for preparing an emulsion with colon targeted delivery function, characterized in that: The method comprises the following steps: S1, adding a cyclodextrin compound to a cationic cellulose nanocrystal suspension for stirring and self-assembly treatment to obtain a composite suspension; S2, adding the anhydrous ethanol solution of flavonoid compounds dropwise to the composite suspension, performing stirring adsorption treatment and rotary evaporation treatment in sequence, to obtain a mixture suspension; S3, adding pectin compounds to the mixture suspension and stirring and mixing them to obtain a wall material solution; S4, mixing the oil phase with the wall material solution and then performing shearing treatment to obtain an emulsion with colon-targeted delivery function.

2. The preparation method according to claim 1, wherein In step S1, in the cationic cellulose nanocrystal suspension, the mass fraction of the cationic cellulose nanocrystal is 0.02-0.40% by weight; The amount of the cyclodextrin compound added is 1.5-2.5 g per 100 mL of the cationic cellulose nanocrystal suspension; The conditions of the stirring self-assembly treatment include: temperature of 25-45°C, stirring rate of 200-450r / min, and time of 20-60min; The cyclodextrin compound is cyclodextrin and / or cyclodextrin derivatives, wherein the cyclodextrin is selected from one or more of α-cyclodextrin, β-cyclodextrin and λ-cyclodextrin; the cyclodextrin derivative is selected from one or more of hydroxyglucosyl-cyclodextrin, carboxymethyl-β-cyclodextrin and 2-hydroxypropyl-β-cyclodextrin.

3. The preparation method according to claim 1, wherein In step S2, the mass concentration of the anhydrous ethanol solution of the flavonoid compound is 1-10 mg / mL; The dripping rate of the anhydrous ethanol solution of the flavonoid compound is 1-3 drops / second; In the mixture suspension, the mass fraction of the flavonoid compound is 0.1-0.5 mg / mL; The stirring adsorption treatment conditions include: temperature of 25-45°C, stirring rate of 200-450r / min, and time of 1-10min; The conditions of the rotary evaporation treatment include: temperature of 30-45°C and time of 5-10 minutes; The flavonoid compound is selected from naringenin and / or quercetin.

4. The preparation method according to claim 1, wherein In the wall material solution, the mass concentration of the pectin compound is 1.5-40 mg / mL; The stirring and mixing treatment conditions include: temperature of 25-45°C, stirring rate of 200-450r / min, and time of 3-24h; The pectin compound is low-ester pectin, and the esterification degree of the low-ester pectin is less than 30%; wherein the low-ester pectin is selected from one or more of citrus pectin, apple pectin and beet pectin.

5. The preparation method according to claim 1, wherein The amount of the oil phase added is 1.0-12.0 g, preferably 5.0-10.0 g, per 100 mL of the wall material solution; Wherein, the oil phase is selected from one or more of medium chain triglycerides, peanut oil, soybean oil, olive oil, rice bran oil, rapeseed oil and linseed oil; The shearing treatment conditions include: a shearing speed of 8000-12000 rpm / min; and a shearing time of 2-5 min.

6. An emulsion with colon targeted delivery function prepared by the preparation method according to any one of claims 1 to 5.

7. The emulsion according to claim 6, wherein The emulsion contains an aqueous phase and an oil phase; The aqueous phase contains cyclodextrin compounds, cationic cellulose nanocrystals, flavonoid compounds and pectin compounds; The oil phase is selected from one or more of medium chain triglycerides, peanut oil, soybean oil, olive oil, rice bran oil, rapeseed oil and linseed oil.

8. The emulsion according to claim 7, wherein Based on the total weight of the aqueous phase, the content of the cyclodextrin compound is 1.5-2.5% by weight, the content of the cationic cellulose nanocrystal is 0.02-0.40% by weight, the content of the flavonoid compound is 0.1-0.5% by weight, and the content of the pectin compound is 0.5-4.0% by weight; Based on the total weight of the emulsion, the content of the water phase is 90.0-99.0% by weight, and the content of the oil phase is 1.0-10.0% by weight.

9. The emulsion according to claim 8, wherein The cyclodextrin compound is cyclodextrin and / or cyclodextrin derivatives, wherein the cyclodextrin is selected from one or more of α-cyclodextrin, β-cyclodextrin and λ-cyclodextrin; the cyclodextrin derivative is selected from one or more of hydroxyglucosyl-cyclodextrin, carboxymethyl-β-cyclodextrin and 2-hydroxypropyl-β-cyclodextrin; The flavonoid compound is selected from naringenin and / or quercetin; The pectin compound is low-ester pectin, and the esterification degree of the low-ester pectin is less than 30%; wherein the low-ester pectin is selected from one or more of citrus pectin, apple pectin and beet pectin.

10. Use of the emulsion according to any one of claims 6 to 9 in preparing a functional product for targeted delivery of flavonoid compounds to the colon; wherein, The functional product is selected from food or medicine; The flavonoid compound is selected from naringenin and / or quercetin.

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