Multifunctional emulsion based on natural composite raw materials and preparation method thereof

Abstract

The invention discloses a multifunctional emulsion based on natural composite raw materials and a preparation method thereof. The emulsion is of an oil-in-water type, composite particles composed of jackfruit and durian seed inner seed coat particles and tea polyphenol are dispersed in a water phase, and an oil phase can be selected from one or more of n-decane, o-xylene and olive oil. The preparation method comprises the following steps: firstly, obtaining the composite particles, ultrasonically dispersing, standing and diluting, then adding the tea polyphenol, and emulsifying with the oil phase. Experiments show that the emulsion is excellent in performance, the peroxide value is increased by not more than 20% after the emulsion is stored at normal temperature for 3 months, and the oxidation resistance is high; after standing for 1 month at 20-30 DEG C, obvious layering and demulsification are avoided, the oil phase separation rate after centrifugation does not exceed 5%, and the stability is good; the effect of inhibiting common bacteria is outstanding, and the antibacterial property is good. Compared with the prior art, natural raw materials are utilized, the risk of synthesizing an emulsifier is avoided, multi-functionalization is achieved through the synergistic effect of the raw materials, and the preparation method is simple and has wide application prospects.

Description

Technical Field

[0001] The present invention relates to the technical field of emulsion preparation, and particularly to a multifunctional emulsion based on natural composite raw materials and a preparation method thereof. Background Art

[0002] An emulsion system stabilized by a particulate emulsifier is generally called a Pickering emulsion system. According to the different properties of the particles used to stabilize the Pickering emulsion, the particles can be classified into: inorganic solid particles, polymer self-assembled particles, natural particles, Janus particles, solid surfactants, etc. These particles can be roughly divided into two types according to the synthesis method: one is artificially synthesized modified particles, and the other is natural particles. For artificially synthesized modified particles, the particles usually cannot stabilize the Pickering emulsion well before modification. This is because the original particles are too hydrophilic and too weakly lipophilic; or because they are too lipophilic and too weakly hydrophilic, thus lacking the amphiphilicity required to stabilize the Pickering emulsion. Therefore, it is necessary to make the particles amphiphilic by increasing or decreasing the hydrophilic-lipophilic balance of the particles themselves in order to stabilize the Pickering emulsion. Natural particles themselves have a certain degree of amphiphilicity, so they can stabilize the Pickering emulsion without any modification.

[0003] Chinese Patent (CN111116941B) discloses a preparation method of a nano-starch-based Pickering emulsion. The invention provides an efficient, green and environmentally friendly preparation method of a nano-starch-based Pickering emulsion. The uniform nano-starch particles are used as an embedding material for vegetable oil, which can improve the stability and digestibility of the emulsion. However, its preparation temperature reaches 45 degrees Celsius above room temperature, and the preparation method is relatively complex, and additional emulsifiers and cross-linking agents are required to assist in forming the emulsion.

[0004] Chinese Patent (CN115232328A) discloses a method for preparing a Pickering emulsion using ribbon-shaped nanocellulose and its application. The invention uses a new technical material, ribbon-shaped nanocellulose, to prepare a stable Pickering emulsion at a very low content. However, it still needs to add a certain amount of additives additionally.

[0005] Jackfruit is an evergreen tree belonging to the genus Artocarpus in the family Moraceae. Jackfruit is a tropical fruit, and its flesh can be eaten fresh or processed into canned food, fruit preserves, and fruit juice. The seeds are rich in starch and can be cooked; the sap and leaves are used medicinally to reduce swelling and detoxify; the flesh has the effects of quenching thirst, promoting lactation, and tonifying the middle qi; the jackfruit tree has a regular shape, a large and shady crown, and strange fruits, making it an excellent shade tree and street tree in the garden; the wood of a jackfruit tree over a hundred years old is golden yellow and hard, and can be used to make furniture or as a yellow dye. Among them, the seeds of jackfruit have various functions and effects, including clearing heat and detoxifying, moistening the intestines and relieving constipation, lowering blood sugar, beautifying the skin, and anti-inflammatory. These effects also expand the application fields for the application prospects of Pickering emulsions.

[0006] Therefore, it is necessary to provide a multifunctional emulsion based on natural composite raw materials and its preparation method to solve the above technical problems. Summary of the Invention

[0007] The purpose of the present invention is to provide a multifunctional emulsion based on natural composite raw materials and its preparation method. By utilizing the advantages of natural raw materials and optimizing the combination and preparation process of the inner seed coats of jackfruit and durian, the multifunctionalization of the emulsion is achieved, with excellent antioxidant, antibacterial properties, and good stability.

[0008] To achieve the above purpose, the present invention provides the following technical solutions: In the first aspect of the present invention, a multifunctional emulsion based on natural composite raw materials is provided. The multifunctional emulsion belongs to the oil-in-water type, and solid particles are uniformly dispersed in both the emulsion droplet interface and the continuous phase. From the perspective of the weight component composition, the aqueous phase is the basic carrier, in which composite particles composed of jackfruit inner seed coat particles and durian inner seed coat particles are dispersed, accounting for 0.006 - 0.5 parts. These two kinds of inner seed coat particles are combined according to an accurate mass ratio of 1:1 - 5:1, exerting a unique synergistic effect. In addition, 0.1 - 0.5 parts of tea polyphenols are added to the aqueous phase, and water is used as the balance, providing a stable dispersion environment for other components. The proportion of the oil phase is 0.1 - 1 part, and one or more substances can be selected from n-decane, o-xylene, olive oil, etc. Different selections of the oil phase will have a significant impact on the final performance of the emulsion, such as solubility, texture, and application characteristics.

[0009] In a second aspect, the present invention provides a method for preparing a multifunctional emulsion based on natural composite raw materials. The preparation of composite particles is the key starting step. First, the dried jackfruit seeds and durian seeds are mechanically peeled separately to obtain pure endosperms. Then, the two are mixed in a specific mass ratio and put into a pulverizer, and pulverized at a high speed of 20,000 - 30,000 r / min for 3 - 8 minutes to convert the endosperms into fine particles. The pulverized powder is screened through a 200 - 500 - mesh sieve to remove large particles that do not meet the requirements and ensure the uniformity of the particles. The material passing through the sieve is dried in an oven at 40 - 50 °C until constant weight for standby. In the particle dispersion stage, composite particles are taken and added to deionized water to prepare an aqueous solution, and ultrasonic dispersion is carried out for 1 - 3 minutes at a power of 80 - 100 W using an ultrasonic processor to promote the uniform dispersion of the particles. The dispersion liquid is covered with a plastic wrap and left to stand for 12 - 36 h to allow the particles to fully precipitate and stabilize. Then, the supernatant is taken and diluted to ensure that the weight component of the composite particles in the solution after dilution is 0.006 - 0.5 parts. Next, 0.1 - 0.5 parts by weight component of tea polyphenols are added to the diluted solution and stirred evenly. Finally, in the emulsion preparation stage, an oil phase is added to the solution containing tea polyphenols. First, it is stirred at a low speed of 1000 - 3000 r / min for 2 - 5 minutes to initially mix the oil phase and the water phase to form a preliminary emulsification system. Subsequently, the stirring speed is increased to 8000 - 12000 r / min and stirring is continued for 1 - 3 minutes to complete the emulsification process and make the emulsion more uniform and stable. The emulsified emulsion is transferred to an environment at 20 - 30 °C and left to stand to further promote the stability and maturation of the emulsion.

[0010] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. The present invention selects the endosperms of jackfruit and durian as the raw materials for the emulsifier. After the combination of the endosperm particles of jackfruit and durian in the present invention, a stable interfacial film is formed at the oil - water interface. Their surface chemical properties and microstructures are complementary. The endosperm particles of jackfruit are rich in hydrophilic groups and can be tightly combined with the water phase; the endosperm particles of durian have certain hydrophobic regions and have a good affinity with the oil phase. This complementary structure enables them to be closely arranged at the oil - water interface, strengthening the strength of the interfacial film and effectively preventing the coalescence and floating of oil droplets, greatly improving the stability of the emulsion.

[0011] 2. The addition of tea polyphenols in the present invention further enhances the function of the emulsion. The phenolic hydroxyl groups in tea polyphenols have strong antioxidant properties, which can scavenge free radicals in the emulsion, inhibit the oxidation reaction of the oil phase, and extend the shelf life of the emulsion. At the same time, the composite particles can encapsulate tea polyphenols, delay their release rate, and make the antioxidant effect more persistent. In terms of antibacterial properties, tea polyphenols can damage the cell membrane structure of bacteria and inhibit bacterial growth. The presence of composite particles increases the contact area between tea polyphenols and bacteria, making the antibacterial effect more significant. Through experimental detection, the emulsion prepared by the present invention has a peroxide value increase of no more than 20% after being stored at room temperature for 3 months, indicating its excellent antioxidant performance; after standing at 20 - 30 °C for 1 month, there is no obvious stratification or demulsification phenomenon, and the oil phase separation rate after centrifugation is no more than 5%, reflecting good stability; and it has outstanding antibacterial properties against common bacteria. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a schematic diagram of the preparation process of the inner seed coat particle powder of plant seeds in the present invention; Figure 2 It is the appearance photo and microscopic photo taken after one month of the n - decane / water emulsion (8 mL / 8 mL) stabilized by 500 - mesh jackfruit inner seed coat particles and durian seed supernatant at different concentrations (wt.%); the numbers marked on the upper part of the sample bottle are sample numbers, indicating that the particle concentrations are in turn: 0, 0.0003, 0.0006, 0.0009, 0.0018, 0.003, 0.006 wt.%, and emulsion droplets start to appear from the third sample; Figure 3 It is the appearance of the jackfruit inner seed coat and its water contact angle diagram (a) the front of the inner seed coat (b) the back of the inner seed coat in the present invention; Figure 4 It is the appearance photo taken after one month of the o - xylene / water emulsion (8 mL / 8 mL) stabilized by 500 - mesh jackfruit inner seed coat particles and durian seed supernatant at different concentrations (wt.%) in Test Example 2 of the present invention; the numbers marked on the upper part of the sample bottle are sample numbers, indicating that the particle concentrations are in turn: 0, 0.001, 0.003, 0.006, 0.01, 0.03 wt.%; Figure 5 It is the appearance photo taken after one month of the olive oil / water emulsion (8 mL / 8 mL) stabilized by 500 - mesh jackfruit inner seed coat particles and durian seed supernatant at different concentrations (wt.%) in Test Example 3 of the present invention; the numbers marked on the upper part of the sample bottle are sample numbers, indicating that the particle concentrations are in turn: 0, 0.001, 0.003, 0.006, 0.01, 0.03, 0.06 wt.%; Figure 6The appearance photos of 500 mesh jackfruit endocarp particles and triglyceride / water emulsion (8 mL / 8 mL) stabilized by durian seeds of different concentrations (wt.%) in Test Example 4 of the present invention taken one month later; the numbers marked on the upper part of the glass bottle are sample numbers, indicating that the particle concentrations are: 0, 0.001, 0.003, 0.006, 0.01, 0.03, 0.06 wt.%; Figure 7 A line chart showing the growth of peroxide values ​​of the emulsions prepared in various embodiments and comparative examples of the present invention after being stored at room temperature for 3 months; Figure 8 A line graph comparing the inhibition rates of the emulsions prepared in various embodiments and comparative examples of the present invention on Escherichia coli; Figure 9 The figure is a line chart comparing the inhibition rates of the emulsions prepared in various embodiments and comparative examples of the present invention on Staphylococcus aureus. DETAILED DESCRIPTION

[0013] The technical solution of the present invention will be clearly and completely described below in conjunction with specific embodiments. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0014] Example 1: Preparation of composite particles: Select dried jackfruit seeds and durian seeds, and carefully peel off the endocarp using a knife. Accurately weigh the jackfruit endocarp and durian endocarp in a mass ratio of 1:1 and mix them thoroughly. Put the mixed endocarp into a high-speed grinder, set the speed to 20,000 r / min, and grind for 3 minutes. The crushed powder is sieved through a 200-mesh sieve, and the sieved material is collected and placed in an oven at 40°C to dry to constant weight, thereby obtaining the composite particles for use.

[0015] Particle dispersion and tea polyphenol addition: Accurately weigh an appropriate amount of the above-mentioned composite particles, add deionized water to prepare an aqueous solution with a mass fraction of 0.5wt%. Use an ultrasonic processor, set the power to 80W, and ultrasonically disperse the solution for 1 minute to ensure that the composite particles are evenly dispersed in the water. Cover the dispersed solution with plastic wrap and let it stand for 12 hours. After 12 hours, take the supernatant and dilute it so that the weight component of the composite particles in the solution is 0.006 parts. Next, accurately weigh 0.1 parts of tea polyphenols according to the weight component, add it to the diluted solution, and stir evenly to ensure that the tea polyphenols are fully dissolved and dispersed.

[0016] Emulsion preparation: n-Decane was selected as the oil phase, and an equal volume of n-decane was added to the solution containing tea polyphenols. The mixture was transferred to a stirring device and pre-stirred at a speed of 1000 r / min for 2 minutes to preliminarily mix the oil phase and the water phase to form a preliminary emulsion. Then, the stirring speed was increased to 8000 r / min and stirring was continued for 1 minute to complete the emulsification process. The emulsified emulsion was transferred to an environment at 20 °C and left to stand for further detection and analysis.

[0017] Example 2: Composite particle preparation: Dry jackfruit seeds and durian seeds were taken. After obtaining the endosperm by mechanical peeling, they were mixed in a mass ratio of 3:1. The mixed endosperm was put into a pulverizer, and the rotation speed was set at 25000 r / min and pulverized for 5 minutes. The pulverized powder was sieved through a 300-mesh sieve, and the material passing through the sieve was dried to a constant weight in an oven at 45 °C to obtain composite particles.

[0018] Particle dispersion and tea polyphenol addition: The composite particles were added to deionized water to prepare an aqueous solution with a mass fraction of 0.5 wt%. It was ultrasonically dispersed for 2 minutes with a ultrasonic processor at a power of 90 W. After the solution was covered with plastic wrap and left to stand for 24 h, the supernatant was taken and diluted to make the weight component of the composite particles 0.2 parts. Then, 0.3 parts of tea polyphenols were added according to the weight component and stirred evenly.

[0019] Emulsion preparation: Olive oil was used as the oil phase, and an equal volume of olive oil was added to the solution containing tea polyphenols. First, it was pre-stirred at a speed of 2000 r / min for 3 minutes, and then the speed was increased to 10000 r / min and stirred for 2 minutes to complete emulsification. The emulsified emulsion was left to stand in an environment at 25 °C.

[0020] Example 3: Composite particle preparation: The endosperms of dry jackfruit seeds and durian seeds were mixed in a mass ratio of 5:1, put into a pulverizer, and pulverized at a rotation speed of 30000 r / min for 8 minutes. The pulverized powder was sieved through a 500-mesh sieve, and the material passing through the sieve was dried to a constant weight in an oven at 45 °C.

[0021] Particle dispersion and tea polyphenol addition: The composite particles were prepared into an aqueous solution with 0.5 wt%, and ultrasonically dispersed for 3 minutes with a ultrasonic processor at a power of 100 W. After the solution was left to stand for 36 h, the supernatant was taken and diluted to make the weight component of the composite particles 0.5 parts. 0.5 parts of tea polyphenols were added according to the weight component and stirred evenly.

[0022] Emulsion preparation: o-Xylene was selected as the oil phase. After adding an equal volume of o-xylene, it was first pre-stirred at a speed of 3000 r / min for 5 minutes, and then stirred at a speed of 12000 r / min for 3 minutes to complete emulsification. The emulsified emulsion was left to stand in an environment at 30 °C.

[0023] To verify the advantages of the composite particles in the present invention, the following comparative experiments will be carried out on the jackfruit endocarp particles alone with reference to the above-mentioned embodiment content. The verification of the effect of the durian endocarp particles is the same by analogy: Comparative Example 1 Particle preparation: Only jackfruit endocarp particles are used and operated according to the preparation method of the composite particles in Example 1. That is, after the dried jackfruit seed endocarp is mechanically peeled, it is pulverized at a speed of 20,000 r / min for 3 minutes, sieved through a 200-mesh sieve, and dried in an oven at 40 °C to constant weight.

[0024] Particle dispersion and tea polyphenol addition: The same as in Example 1, the composite particles are formulated into an aqueous solution with a concentration of 0.5 wt%, ultrasonically dispersed, allowed to stand, diluted, and then 0.1 part of tea polyphenol is added and stirred evenly.

[0025] Emulsion preparation: Using n-decane as the oil phase, according to the emulsion preparation method in Example 1, first pre-stir at 1000 r / min for 2 minutes, then stir at 8000 r / min for 1 minute, and the emulsion is allowed to stand in an environment at 20 °C.

[0026] Comparative Example 2 Particle preparation: Only durian endocarp particles are used, and the preparation process is the same as that of the composite particles in Example 1, except that the raw material is only durian endocarp.

[0027] Particle dispersion and tea polyphenol addition: The same steps as in Example 1 are used for treatment. After preparing the solution, ultrasonic treatment, standing, dilution, 0.1 part of tea polyphenol is added and stirred evenly.

[0028] Emulsion preparation: Using n-decane as the oil phase, the same emulsion preparation method as in Example 1, and allowing it to stand in an environment at 20 °C.

[0029] Comparative Example 3 Composite particle preparation: Jackfruit endocarp particles and durian endocarp particles are mixed in a mass ratio of 1:1, and the preparation process is the same as that in Example 1.

[0030] Particle dispersion: The same as in Example 1, except that tea polyphenol is not added.

[0031] Design of emulsion performance comparison experiments prepared based on the above examples and comparative examples: The purpose of the experiment is to compare the performance differences of emulsions under different formulations and preparation conditions, and to verify the effects of the combination of jackfruit and durian endocarp particles and the addition of tea polyphenols on the antioxidant property, stability and antibacterial property of the emulsion.

[0032] Materials: Dried jackfruit seeds, durian seeds, tea polyphenols, n-decane, o-xylene, olive oil, deionized water, Escherichia coli bacterial solution, Staphylococcus aureus bacterial solution, nutrient agar medium, etc.

[0033] Equipment: cutter, high-speed grinder, 200-500 mesh sieve, oven, analytical balance, ultrasonic processor, stirring device, centrifuge, constant temperature incubator, spectrophotometer, etc.

[0034] Experimental grouping 1. Example group: Example 1: The composite particles are composed of jackfruit and durian endocarp in a mass ratio of 1:1. The composite particles account for 0.006 parts in the aqueous phase, 0.1 part of tea polyphenols, and the oil phase is n-decane.

[0035] Example 2: The mass ratio of the composite particles is 3:1. The composite particles account for 0.2 parts in the aqueous phase, 0.3 part of tea polyphenols, and the oil phase is olive oil.

[0036] Example 3: The mass ratio of the composite particles is 5:1. The composite particles account for 0.5 parts in the aqueous phase, 0.5 part of tea polyphenols, and the oil phase is o-xylene.

[0037] 2. Control group: Control 1: Only use jackfruit endocarp particles. The composite particles account for 0.006 parts in the aqueous phase, 0.1 part of tea polyphenols, and the oil phase is n-decane.

[0038] Control 2: Only use durian endocarp particles. The composite particles account for 0.006 parts in the aqueous phase, 0.1 part of tea polyphenols, and the oil phase is n-decane.

[0039] Control 3: The composite particles are composed of jackfruit and durian endocarp in a mass ratio of 1:1. The composite particles account for 0.006 parts in the aqueous phase, tea polyphenols are not added, and the oil phase is n-decane.

[0040] Experimental procedures 1. Emulsion preparation: According to the preparation methods of the composite particles in the examples and control groups of the present invention, the composite particles of each formulation are obtained respectively. For example, the dry jackfruit and durian seeds are mechanically peeled of the endocarp, mixed in the corresponding mass ratio, pulverized at 20000-30000 r / min for 3-8 minutes, screened through a sieve, and dried in an oven at 40-50 °C to constant weight.

[0041] Take the composite particles and add deionized water to prepare an aqueous solution with a mass fraction of 0.5 wt%. Disperse them ultrasonically at a power of 80-100 W for 1-3 minutes with an ultrasonic processor, cover with plastic wrap and let stand for 12-36 h, and take the supernatant and dilute it to obtain composite particle solutions with different concentrations.

[0042] Add tea polyphenols according to the formulation and stir evenly, then add the corresponding oil phase. First, pre-stir at 1000-3000 r / min for 2-5 minutes, then increase the rotation speed to 8000-12000 r / min and stir for 1-3 minutes. After emulsification, let stand at 20-30 °C.

[0043] 2. Antioxidant test: The peroxide value of the emulsion was determined by the iodometric method. The emulsion was stored at room temperature for 3 months, and equal amounts of emulsion samples were taken at the 0th month and the 3rd month respectively.

[0044] An excessive amount of potassium iodide solution was added to the sample. Under acidic conditions, the peroxides in the emulsion reacted with potassium iodide to generate iodine.

[0045] The generated iodine was titrated with a standard sodium thiosulfate solution, and the peroxide value was calculated based on the volume of the sodium thiosulfate solution consumed. The growth of the peroxide value of different samples within 3 months was compared.

[0046] 3. Stability test: Static observation: The emulsion sample was left standing in an environment of 20 - 30 °C for 1 month, and whether the emulsion showed stratification or demulsification was observed regularly and recorded.

[0047] Centrifugation test: Equal amounts of emulsion samples were placed in centrifuge tubes and centrifuged at a speed of 3000 r / min for 15 min. The separation of the oil phase after centrifugation was observed, and the oil phase separation rate was measured and calculated.

[0048] 4. Antibacterial test: Preparation of bacterial suspension: Escherichia coli and Staphylococcus aureus were respectively inoculated onto nutrient agar media and cultured in a constant temperature incubator at 37 °C for 18 - 24 h. Then the colonies were rinsed with sterile normal saline to prepare a bacterial suspension with a certain concentration.

[0049] Antibacterial experiment: The plate coating method was used. A certain amount of bacterial suspension was evenly coated on the nutrient agar medium plate, and then sterile Oxford cups were placed on the plate. Equal amounts of emulsion samples were added to the Oxford cups. After culturing in a constant temperature incubator at 37 °C for 24 h, the diameter of the antibacterial zone was measured, the antibacterial rate was calculated, and the inhibitory effects of different emulsions on the two bacteria were compared.

[0050] The following is a comparison table of experimental data between each example and the comparative example:

[0051] The experimental data of the emulsion in the examples and the comparative example were analyzed from three aspects: antioxidant property, stability, and antibacterial property. 1. Antioxidant property: After 3 months of storage at room temperature, the peroxide value increases of the emulsions in Examples 1 - 3 are 15%, 18% and 16% respectively, while those of Comparative Examples 1 - 3 reach 30%, 28% and 25%. This indicates that the emulsion in the example added with the composite particles of jackfruit and durian endocarp and tea polyphenols has significantly better antioxidant performance than the emulsion in the comparative example that only uses a single endocarp particle or does not add tea polyphenols. The phenolic hydroxyl group of tea polyphenols has strong antioxidant properties, can effectively scavenge free radicals, and inhibit the oxidation of the oil phase. The encapsulation effect of the composite particles on tea polyphenols further extends its antioxidant time.

[0052] 2. Stability: In the stability test of standing at 20 - 30 °C for 1 month, there is no obvious delamination and demulsification phenomenon in Examples 1 - 3, and the oil phase separation rates after centrifugation are also relatively low, being 3%, 4% and 3.5% respectively. In contrast, slight delamination occurs in Comparative Examples 1 - 3, and the oil phase separation rates are 8%, 7% and 6% respectively. This shows that the surface chemical properties and microstructure of jackfruit and durian endocarp particles are complementary. After being mixed in a specific proportion, the stable film formed at the oil - water interface greatly enhances the stability of the emulsion and effectively prevents the coalescence and floating of oil droplets.

[0053] 3. Antibacterial property: In the inhibition experiments against Escherichia coli and Staphylococcus aureus, the inhibition rates of Examples 1 - 3 are significantly higher than those of the comparative examples. The inhibition rate of Example 1 against Escherichia coli is 85%, and the inhibition rate against Staphylococcus aureus is 83%; the inhibition rate of Example 2 against Escherichia coli is 88%, and the inhibition rate against Staphylococcus aureus is 87%; the inhibition rate of Example 3 against Escherichia coli is 86%, and the inhibition rate against Staphylococcus aureus is 84%. The inhibition rates of Comparative Examples 1 - 3 against the two bacteria are relatively low, with the inhibition rate against Escherichia coli being between 60% - 70% and the inhibition rate against Staphylococcus aureus being between 55% - 68%. This indicates that the antibacterial effect of tea polyphenols in destroying the cell membrane structure, synergistically with the composite particles increasing its contact area with bacteria, significantly improves the antibacterial performance of the emulsion.

[0054] In summary, the combination of jackfruit and durian endocarp particles in the present invention, as well as the synergistic effect with tea polyphenols, significantly improves the antioxidant property, stability and antibacterial property of the emulsion. Compared with the emulsion of a single endocarp or without added tea polyphenols in the comparative example, the performance advantages are obvious.

[0055] For those skilled in the art, it is obvious that the present invention is not limited to the details of the above - mentioned exemplary embodiments, and without departing from the spirit or basic characteristics of the present invention, the present invention can be implemented in other specific forms. Therefore, from any point of view, the embodiments should be regarded as exemplary and non - restrictive. The scope of the present invention is defined by the appended claims rather than the above description. Therefore, it is intended to include all changes falling within the meaning and scope of the equivalent elements of the claims in the present invention.

Claims

1. A multifunctional emulsion based on natural composite raw materials, the emulsion system is an oil-in-water type, and solid particles are dispersed in the emulsion system, characterized in that, The composition of the emulsion system includes by weight components: Aqueous phase: In which there are composite particles composed of two kinds of endopleura particles of fruit seeds dispersed, the composite particles account for 0.006 - 0.5 parts in the aqueous phase, and 0.1 - 0.5 parts of tea polyphenols, with water as the balance; Oil phase: 0.1 - 1 part.

2. The multifunctional emulsion based on natural composite raw materials according to claim 1, characterized in that: The composite particles are composed of jackfruit endopleura particles and durian endopleura particles in a mass ratio of 1:1 - 5:

1.

3. The multifunctional emulsion based on natural composite raw materials according to claim 1, characterized in that: The average particle size of the composite particles is between 100nm and 1000nm.

4. The multifunctional emulsion based on natural composite raw materials according to claim 1, wherein: The oil phase is one or more of n-decane, o-xylene, and olive oil.

5. A method for preparing the multifunctional emulsion based on natural composite raw materials according to any one of claims 1-4, characterized in that, It includes the following steps: (1) Preparation of composite particles: Mechanically peel the dried jackfruit seeds and durian seeds respectively to obtain the endopleura; mix the two endopleuras in a mass ratio of 1:1 - 5:1, and place the mixture in a pulverizer, pulverize it at a rotation speed of 20000 - 30000r / min for 3 - 8 minutes; sieve the pulverized powder through a 200 - 500 mesh sieve, and take the material under the sieve and dry it in an oven at 40 - 50°C until constant weight for standby; (2) Particle dispersion: Take the above composite particles, add deionized water to prepare an aqueous solution, and ultrasonically disperse it using an ultrasonic processor; after covering the dispersion with plastic wrap and standing for several hours, take the supernatant and dilute it into a solution, and the weight component of the composite particles in the solution after dilution is 0.006 - 0.5 parts; (3) Addition of tea polyphenols: Add tea polyphenols to the diluted solution according to the weight component of 0.1 - 0.5 parts, and stir evenly; (4) Emulsion preparation: Add the oil phase to the solution containing tea polyphenols, and stir at a low rotation speed in a stirring device to make the oil phase and the aqueous phase preliminarily mixed; then increase the stirring speed and continue stirring to complete the emulsification process; transfer the emulsified emulsion to an environment at 20 - 30°C and let it stand.

6. The preparation method of the multifunctional emulsion based on natural composite raw materials according to claim 4, characterized in that: In step (2), ultrasonically disperse it for 1 - 3 minutes using an ultrasonic processor at a power of 80 - 100W; after covering the dispersion with plastic wrap and standing for 12 - 36h, take the supernatant and dilute it into a solution.

7. The preparation method of the multifunctional emulsion based on natural composite raw materials according to claim 4, characterized in that: In step (4), pre-stir at a rotation speed of 1000 - 3000r / min for 2 - 5 minutes to make the oil phase and the aqueous phase preliminarily mixed; then increase the stirring speed to 8000 - 12000r / min and continue stirring for 1 - 3 minutes to complete the emulsification process.

8. The preparation method of the multifunctional emulsion based on natural composite raw materials according to claim 4, characterized in that: The two kinds of endopleura composite particles form a stable particle interfacial film at the oil-water interface due to the complementarity of their surface chemical properties and microscopic structures.

9. The preparation method of the multifunctional emulsion based on natural composite raw materials according to claim 4, characterized in that: Tea polyphenols cooperate with the composite particles. Its phenolic hydroxyl groups have antioxidant properties, the composite particles encapsulate and delay its release, and it helps to increase the contact area with bacteria.

10. The preparation method of the multifunctional emulsion based on natural composite raw materials according to claim 4, characterized in that: The prepared emulsion has a peroxide value increase of no more than 20% after being stored at room temperature for 3 months, no obvious stratification and demulsification after standing at 20 - 30°C for 1 month, and an oil phase separation rate of no more than 5% after centrifugation.

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