Essential oil-loaded polysaccharide-based high internal phase emulsion system and application thereof

Abstract

The invention relates to a method for preparing a high-efficiency loaded essential oil system by utilizing a polysaccharide-based high internal phase emulsion and an application of the high-efficiency loaded essential oil system. The preparation method has the advantages that firstly, the preparation method of the essential oil-loaded polysaccharide-based high internal phase emulsion is green, simple and efficient, and the essential oil-loaded polysaccharide-based high internal phase emulsion can be successfully prepared through one-step shearing dispersion; secondly, the essential oil and the vegetable oil can be mutually dissolved in any proportion, so that the loading capacity of the essential oil is accurately controlled; thirdly, the system can obviously inhibit volatilization of essential oil, and the effect of protecting the essential oil is achieved; fourthly, the system has good gelling property, viscoelasticity, plasticity, storage stability, thermal stability and temperature responsiveness; fifthly, the essential oil or the mixed oil phase of the vegetable oil and the essential oil can further load oil-soluble functional active substances; sixthly, the system can be successfully applied to a food system and has a remarkable adjusting effect on flavor; and 7, when the system is applied to a food system, the oxidation resistance and the antibacterial property are remarkably improved, and the generation amount of primary oxidation products and secondary oxidation products can be reduced.

Description

Technical Field

[0001] The present invention relates to the field of high internal phase emulsions, in particular to a polysaccharide-based high internal phase emulsion system loaded with essential oils and applications thereof. Background Art

[0002] In recent years, essential oils have shown important application value in the food industry due to their excellent antioxidant and antibacterial properties. Their antioxidant activity comes from active ingredients such as phenols (such as thymol), terpenes (limonene, linalool) and aldehydes (citral), which can effectively block free radical chain reactions and inhibit lipid oxidation, thereby reducing the loss of nutrients during processing and storage. A typical example is that jam with 0.03% of Litsea cubeba essential oil maintains its original flavor while significantly extending its shelf life. At the same time, essential oils have broad-spectrum antibacterial properties and show inhibitory effects on bacteria (such as spoilage bacteria in dairy products), fungi (such as Penicillium citrinum) and viruses. For example, a chitosan coating containing thymol can reduce the mildew rate of citrus by 50%, while a tea tree essential oil composite coating has an antibacterial rate of 35%. In systems such as dairy products, the introduction of essential oils such as oregano and cloves not only gives the product a natural aroma, but also reduces the risk of microbial contamination by 2-3 logarithmic levels, having the dual advantages of functional enhancement and sensory enhancement. This synergistic effect of "natural preservative-flavor modification" makes it an ideal functional ingredient for clean label food development.

[0003] However, essential oils are generally volatile and have poor stability, and there may be certain difficulties in using them directly in food systems. Therefore, methods such as essential oil loading and encapsulation are widely used in the encapsulation and protection of essential oils to improve their stability and efficacy in food systems. As a system with a special structure, high internal phase emulsions (HIPEs) provide a highly promising solution for essential oil loading due to their high internal phase volume fraction and unique interfacial properties, which can effectively improve the loading rate, dispersibility and stability of essential oils. Previous studies have confirmed that high internal phase emulsions stabilized by single polysaccharides have good stability, gelation and plasticity, but their essential oil loading properties have not been explored. Summary of the Invention

[0004] The purpose of the present invention is to address the deficiencies in the prior art and provide a polysaccharide-based high internal phase emulsion system loaded with essential oils and its application, aiming to reveal its potential application value in this field, provide a new technical path for expanding the application scope of essential oils, and also provide new research ideas for the functional development of high internal phase emulsions, enriching and improving the theoretical and technical system of high internal phase emulsions in the field of loading active ingredients.

[0005] To achieve the above object, the technical solution adopted by the present invention is:

[0006] In a first aspect, the present invention provides a polysaccharide-based high internal phase emulsion system loaded with essential oils, which is prepared by the following method:

[0007] 1) preparing an aqueous solution containing a polysaccharide substance and adjusting the pH as the aqueous phase;

[0008] 2) Mixing essential oils and vegetable oils as the oil phase;

[0009] 3) mixing the aqueous phase prepared in step 1) and the oil phase prepared in step 2) to obtain the essential oil-loaded polysaccharide-based high internal phase emulsion system;

[0010] Wherein, the essential oil is selected from at least one of lemon essential oil, clove essential oil and perilla essential oil.

[0011] The polysaccharide substance in step 1) is at least one selected from chitosan hydrochloride, carboxymethyl chitosan, sodium carboxymethyl cellulose, pectin, and sodium alginate.

[0012] Optionally, the mass concentration of the aqueous solution of the polysaccharide substance in the aqueous phase in step 1) is 0.05-3.0%.

[0013] Furthermore, the aqueous solution in step 1) is pure water, and a certain amount of NaCl may be added, and the stability of the system will not be affected when the concentration is below 500 mmol.

[0014] The pH adjustment method in step 1) is as follows, referring to the inventors' prior applications CN113461968A, CN114573832A, and CN115594865A:

[0015] Furthermore, in step 1), the chitosan hydrochloride aqueous solution has a mass percentage concentration of 0.05 to 3.0 wt % and a pH of 6.0 to 6.7.

[0016] Furthermore, in step 1), the mass percentage concentration of the carboxymethyl chitosan aqueous solution is 0.05-3.0 wt %, and the pH is 6.8-7.2.

[0017] Furthermore, in step 1), the mass percentage concentration of the sodium carboxymethyl cellulose solution is 0.05-3.0 wt %, and the pH is 0.5-5.2.

[0018] Furthermore, in step 1), the mass percentage concentration of the sodium alginate solution is 0.05-3.0 wt %, and the pH is 0.5-4.0.

[0019] Furthermore, the pectin solution in step 1) has a mass percent concentration of 0.05 to 3.0 wt %, and a pH of 0.5 to 4.2.

[0020] Furthermore, in the dispersion of composite particles of chitosan hydrochloride and carboxymethyl chitosan in step 1), the composite mass ratio of chitosan hydrochloride to carboxymethyl chitosan is 1:1, 2:1, 3:1, the concentration is 0.1-3.0 wt%, and the pH is 6.0-6.7.

[0021] Furthermore, step 1) further comprises adding a small amount of inorganic salt or acid-base regulator into the aqueous phase.

[0022] Furthermore, the acid-base regulator is a commercially available hydrochloric acid or sodium hydroxide solution of appropriate concentration, which is used to adjust the pH of the aqueous phase. It is understood that a small amount of other inorganic salt ions or biomolecules such as proteins can also be introduced into the system of the present invention. These inorganic salts, inorganic salt ions, or proteins do not affect the function of the single polysaccharide stabilizer or polysaccharide composite particles in stabilizing the high internal phase emulsion.

[0023] Furthermore, in step 1), the dispersion time is not less than 1 hour, and the standing time is not less than 12 hours.

[0024] Furthermore, the dispersion time is not less than 2 hours, and the standing time is not less than 18 hours. The above dispersion time is set to allow the single polysaccharide stabilizer or polysaccharide composite particles to be fully dispersed in water or aqueous solution, and the standing time is set to allow the polysaccharide substance to be fully hydrated.

[0025] Furthermore, the dispersion temperature in step 1) is room temperature. Specifically, the standing temperature in step S1 is 4°C to 36°C. In certain embodiments of the present invention, the dispersion and standing operations can generally be performed at room temperature, without the need for constant temperature and humidity storage conditions, resulting in convenient and simple operation.

[0026] Furthermore, the standing temperature in step 1) is refrigeration or room temperature.

[0027] In step 2), the vegetable oil is selected from at least one of peanut oil, rapeseed oil, soybean oil, palm oil, linseed oil, castor oil and blended oil.

[0028] Furthermore, the vegetable oil is peanut oil.

[0029] Optionally, the volume content of the essential oil in the oil phase is 5%-100%.

[0030] In step 3), the shear mixing condition is 10000 rpm to 12000 rpm for 20 s to 90 s. The above shear mixing conditions can be used to rapidly prepare a high internal phase emulsion stabilized by the single chitosan polysaccharide or polysaccharide composite particles, thereby obtaining a high internal phase emulsion product loaded with essential oils with excellent performance.

[0031] Furthermore, after shear mixing, the mixture is allowed to stand at 4° C. to 36° C. for more than 2 hours.

[0032] Furthermore, after shear mixing, the mixture is allowed to stand at 4° C. to 36° C. for stratification, and the standing time is more than 2 hours.

[0033] Furthermore, the standing time is more than 12 hours.

[0034] In a second aspect, the present invention provides applications of the polysaccharide-based high internal phase emulsion essential oil loading system described in the first aspect of the present invention, specifically for use in preparing related products, including but not limited to: food, medicine, chemical and bioengineering materials.

[0035] Furthermore, in the above applications, the essential oil-loaded high internal phase emulsion can be used to load functional active ingredients such as β-carotene, and can be used as a fat substitute in the preparation of minced meat products and mayonnaise.

[0036] The present invention adopts the above technical solution, which has the following technical effects compared with the prior art:

[0037] 1) The present invention is the first to use polysaccharides as emulsion stabilizers to prepare high-internal phase emulsions with high efficiency and essential oil loading, without adding other surfactants or inorganic particles. The polysaccharides are green, environmentally friendly, non-toxic, biodegradable, and highly safe.

[0038] 2) The preparation method of the present invention can efficiently and simply prepare a high internal phase emulsion loaded with essential oil by one-step shear dispersion in a high-speed disperser. The equipment is simple, the cost is low, the energy consumption is low, the preparation process is simple and easy, and the effect is good. At the same time, there is no need to adopt or combine other high-energy preparation methods, such as high-pressure homogenization, ultrasound, secondary emulsification, concentration, etc.

[0039] 3) The high internal phase emulsion loaded with essential oil prepared by the present invention forms a milky white or light yellow system under suitable pH conditions, and has strong gelation, good plasticity, high thermal stability and high safety. In the application, the structural characteristics of the prepared high internal phase emulsion loaded with essential oil can be used to apply it to different fields or aspects, such as oil gel loaded with essential oil, 3D or 4D printed food, loaded functional ingredients, mayonnaise-like preparation, simulated minced meat products, etc. Therefore, the high internal phase emulsion loaded with essential oil has good application potential and development value, and can be applied to the development of various products in different fields. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 This is the appearance of the high internal phase emulsion loaded with different types and contents of essential oils in Example 2.

[0041] Figure 2This is an appearance diagram of the high internal phase emulsion containing different types and contents of essential oils after being stored at room temperature for 5 months in Example 2.

[0042] Figure 3 These are laser confocal images of high internal phase emulsions loaded with different types of essential oils in Example 2, wherein A represents a high internal phase emulsion without essential oil, B represents a high internal phase emulsion with 20% by volume of lemon essential oil, C represents a high internal phase emulsion with 20% by volume of clove essential oil, and D represents a high internal phase emulsion with 20% by volume of perilla essential oil.

[0043] Figure 4 The rheological properties of the high internal phase emulsion prepared in Example 2, including: (A) the effect of the elastic (G′, solid) or viscous (G″, hollow) modulus of the high internal phase emulsion loaded with lemon essential oil, (B) the effect of the elastic (G′, solid) or viscous (G″, hollow) modulus of the high internal phase emulsion loaded with clove essential oil, and (C) the effect of the elastic (G′, solid) or viscous (G″, hollow) modulus of the high internal phase emulsion loaded with perilla essential oil.

[0044] Figure 5 The volatilization amount of lemon essential oil in different systems of Example 3 changes with storage time, wherein CMCS1.5 represents CMCS-HIPEs with c=1.5wt%; CMCS0.5 represents CMCS-HIPEs with c=0.5wt%; CHC1.5 represents CHC-HIPEs with c=1.5wt%; CHC0.5 represents CHC-HIPEs with c=0.5wt%; 1:1 1.5 represents CMCS\CHC-HIPEs with a CMCS:CHC ratio of 1:1; 1:1 0.5 represents CMCS\CHC-HIPEs with a CMCS:CHC ratio of 1:1; 1:2 1.5 represents CMCS\CHC-HIPEs with a CMCS:CHC ratio of 1:2; 0.5 represents CMCS / CHC-HIPEs with a CMCS:CHC ratio of 1:2 and a CMCS:CHC ratio of 0.5 wt%; 1:3 represents CMCS / CHC-HIPEs with a CMCS:CHC ratio of 1.5 wt% and a CMCS:CHC ratio of 1:3; 1:3 represents CMCS / CHC-HIPEs with a CMCS:CHC ratio of 0.5 wt% and a CMCS:CHC ratio of 1:3; TW80 represents HIPEs stabilized with Tween 80; the oil phase in all these systems was pure lemon essential oil. LEO represents a control group without encapsulated lemon essential oil.

[0045] Figure 6This is the appearance of the carotene-loaded high internal phase emulsion in Example 5, wherein: (A) 0.5 wt% carboxymethyl chitosan + peanut oil (B) 0.5 wt% carboxymethyl chitosan + peanut oil + clove essential oil (C) 1.5 wt% carboxymethyl chitosan + peanut oil (D) 1.5 wt% carboxymethyl chitosan + peanut oil + clove essential oil (E) Tween + peanut oil (F) Tween + peanut oil + clove essential oil.

[0046] Figure 7 This is the storage stability analysis of the high internal phase emulsion loaded with β-carotene at 25° C. in Example 5, wherein samples 1-8 are peanut oil, peanut oil + clove essential oil, 0.5% CMCS (carboxymethyl chitosan) + peanut oil, 0.5% CMCS + peanut oil and clove essential oil, 1.5% CMCS + peanut oil, 1.5% CMCS + peanut oil and clove essential oil, Tween + peanut oil, and Tween + peanut oil and clove essential oil.

[0047] Figure 8 The appearance of meat patties with different replacement ratios in Example 6 before and after cooking is shown, where Figures A and B are before cooking, and Figures C and D are after cooking.

[0048] Figure 9 Figures 1 and 2 are the analysis of primary oxidation (Figures A and C) and secondary oxidation products (Figures B and D) of meat patties with different replacement ratios in Example 6. Different letters indicate significant differences (P < 0.05).

[0049] Figure 10 This is the mayonnaise-like appearance of different emulsion replacement amounts in Example 7, where the left picture represents the oil phase is pure peanut oil; the right picture represents the oil phase is a peanut oil / clove essential oil mixture.

[0050] Figure 11 This is the appearance characterization of the adhesion performance of the mayonnaise-like substance with different emulsion replacement amounts in Example 7, where: M0-M100 represent different replacement amounts of high internal phase emulsion; A represents the oil phase as pure peanut oil; B represents the oil phase as a mixture of peanut oil and clove essential oil.

[0051] Figure 12 The thermal stability of the mayonnaise-like product with different emulsion addition amounts in Example 7, wherein: M0-M100 represent different proportions of high internal phase emulsion replacement; group M samples represent pure peanut oil as the oil phase; group M' samples represent a peanut oil / clove essential oil mixture as the oil phase. DETAILED DESCRIPTION

[0052] In order to make the purpose, technical solutions and advantages of this application more clearly understood, the present application is described and illustrated below in conjunction with the accompanying drawings and examples. It should be understood that the specific embodiments described herein are merely used to explain this application and are not intended to limit this application. Based on the embodiments provided in this application, all other embodiments obtained by those of ordinary skill in the art without creative work are within the scope of protection of this application.

[0053] Obviously, the drawings described below are merely examples or embodiments of the present application. Those skilled in the art can apply the present application to other similar scenarios based on these drawings without inventive effort. Furthermore, it is also understood that, although the effort involved in such a development process may be complex and lengthy, for those skilled in the art related to the content disclosed in this application, changes in design, manufacturing, or production based on the technical content disclosed in this application are merely conventional technical means and should not be construed as an insufficiency of the content disclosed in this application.

[0054] In the following embodiments, unless otherwise specified, the concentrations of the polysaccharide aqueous solutions are all mass concentrations, the ratios of essential oil to vegetable oil are all volume ratios, the concentrations of essential oil in the oil phase are all volume concentrations, and the ratios of the aqueous phase to the oil phase are all volume ratios.

[0055] Example 1

[0056] This example prepares a polysaccharide-based high internal phase emulsion system loaded with essential oils. The specific process is as follows:

[0057] (1) Prepare a certain amount of polysaccharide aqueous solution, gently stir it at room temperature for 2 hours to fully disperse it, refrigerate it for more than 12 hours to fully hydrate it, and adjust the pH to obtain the aqueous solution as the aqueous phase;

[0058] (2) A certain volume of essential oil and peanut oil were measured and mixed to obtain an oil phase mixture. The oil phase mixture was used as the oil phase, and the aqueous phase and the oil phase were mixed at a volume ratio of 1:4 under high shearing conditions, and sheared at 10,000 rpm to 12,000 rpm for 20 to 90 seconds to obtain a high internal phase emulsion loaded with essential oil.

[0059] Example 2

[0060] In this example, based on the method of Example 1, 15 groups of high internal phase emulsions loaded with essential oils were prepared, wherein the aqueous phase was a 0.8 wt.% carboxymethyl chitosan aqueous solution, and the oil phase was an essential oil-peanut oil mixture with essential oil contents of 0%, 5%, 10%, 20%, and 50%, respectively.

[0061] like Figure 1As shown, high internal phase emulsions loaded with different types of essential oils (lemon, clove, and perilla) and varying amounts all exhibited a gel-like texture. The emulsions without essential oils were pale yellow, while those containing essential oils were milky white. Furthermore, the newly prepared emulsions exhibited a uniform texture and were self-supporting, preventing flow when inverted.

[0062] The high internal phase emulsion did not show obvious delamination, oil leakage, demulsification and other instability phenomena when placed at room temperature for five months. It still appeared milky white and had good self-supporting properties and a gel-like appearance. Figure 2 ), the microstructure shows that the oil droplets are kept tightly packed ( Figure 3 ), showing excellent storage stability. From the experimental results, it can be seen that the essential oil-loaded carboxymethyl chitosan-stabilized high internal phase emulsion prepared in this example has the advantages of high stability, strong gelation, good self-supporting performance, and strong plasticity.

[0063] The dynamic viscoelasticity test results of the emulsion are as follows Figure 4 As shown, the viscoelastic properties of the emulsions are largely unaffected by shear frequency, and all types of emulsions are primarily elastic (elastic modulus G′ > viscous modulus G″). The elastic moduli of the high internal phase emulsions loaded with lemon and perilla essential oils increase with increasing essential oil content, and are all higher than those of the pure peanut oil high internal phase emulsion. However, only the high internal phase emulsion loaded with clove essential oil at 50% content exceeds that of the pure peanut oil high internal phase emulsion, while the other three content levels are all lower. The high internal phase emulsion loaded with 20% clove essential oil has the lowest elastic modulus, while the high internal phase emulsion loaded with 50% essential oil has the highest elastic modulus under the same conditions. The addition of essential oils may alter the properties of the emulsion interfacial film. Some essential oil components can interact with the emulsifier or other components in the emulsion, making the interfacial film more compact and elastic. These results indicate that the carboxymethyl chitosan-stabilized essential oil-loaded high internal phase emulsions possess a very strong, force-resistant gel-like network structure.

[0064] Example 3

[0065] In this embodiment, the aqueous phase is a mixed group of carboxymethyl chitosan-chitosan hydrochloride with different compositions, the specific configuration is shown in Table 1, and the oil phase is pure lemon essential oil. Eleven different systems were prepared by one-step shear dispersion, and lemon essential oil was set as the control group 12 (the volume was equal to the oil phase volume in the other systems).

[0066] Table 1 (The ratios in the following aqueous phase material column are weight ratios)

[0067]

[0068]

[0069] Figure 5The cumulative volatilization of lemon essential oil in different systems after being exposed to the air at 37°C was observed over time. The fastest volatilization occurred in the unencapsulated lemon oil, followed by the emulsion stabilized with the commercial stabilizer TW80. This showed both a higher volatilization volume and a faster volatilization rate, indicating that TW80 had little inhibitory effect on essential oil volatilization. However, the polysaccharide-based high internal phase emulsion exhibited a significant inhibitory effect on essential oil volatilization, with high-concentration polysaccharides performing better than low-concentration polysaccharide-stabilized high internal phase emulsions in suppressing essential oil volatilization. Furthermore, the inhibitory effect of different concentrations of single polysaccharide-based high internal phase emulsions on essential oil volatilization was more pronounced than that of composite polysaccharide-based high internal phase emulsions. Specifically, the cumulative volatilization of essential oil in the 1.5% carboxymethyl chitosan-based high internal phase emulsion after 19 days of storage was only 33% of that of the unencapsulated essential oil.

[0070] Example 4

[0071] In this example, the aqueous phase was a mixture of carboxymethyl chitosan and chitosan hydrochloride of different compositions, the specific configuration of which is shown in Table 2. The oil phase was a mixture of lemon essential oil and peanut oil with a lemon essential oil content of 10%. Twelve groups of essential oil-loaded high internal phase emulsions were prepared by one-step shear dispersion.

[0072] Table 2 (The ratios in the following aqueous phase material column are weight ratios)

[0073]

[0074]

[0075] Then, the antibacterial performance test was carried out by measuring the OD value:

[0076] (1) Preparation of LB liquid culture medium: Weigh 10 g of protein, 10 g of sodium chloride, and 5 g of yeast extract into 1 L of deionized water, adjust the pH to 7.2-7.4, and then sterilize in a commercial pressure sterilizer for later use.

[0077] (2) Preparation of LB solid culture medium: Add 15 g of agar to the above LB liquid culture medium, and then sterilize it in an autoclave for later use.

[0078] (3) Bacterial culture: In a clean bench, the preserved strain was streaked onto LB solid broth using an inoculation loop, and then cultured in a 37°C incubator for 12 h. The strain was then inoculated into LB liquid culture medium using an inoculation loop, and cultured at 37°C for another 12 h.

[0079] (4) The antibacterial properties of the samples were tested by co-culturing the bacterial solution with the samples. First, the bacterial solution was diluted 10-fold and the absorbance (OD) was measured at 600 nm using a microplate reader. The OD was adjusted to 0.1. The samples were then added to the diluted bacterial solution (2%, v / v), with three bottles per group. Finally, the samples were cultured in a 37°C constant temperature incubator. The OD value was measured after 24 hours. The survival of the strain was determined by the OD value. The smaller the OD value, the lower the bacterial solution concentration and the better the antibacterial properties of the sample.

[0080] As shown in Table 3, 24-hour OD monitoring revealed that the OD values ​​of the blank bacterial suspension and the nonionic surfactant Tween 80 group were significantly higher than those of the essential oil-loaded high internal phase emulsion group (p < 0.05), confirming that the blank and Tween 80 groups had essentially no antibacterial activity. The lemon essential oil-loaded system exhibited significantly enhanced antibacterial activity compared to the carboxymethyl chitosan peanut oil group. The chitosan hydrochloride group and the carboxymethyl chitosan:chitosan hydrochloride (1:2) group exhibited significant inhibitory effects against Escherichia coli, while the carboxymethyl chitosan group and the chitosan hydrochloride (1:1) group exhibited significant antibacterial activity against Staphylococcus aureus. Furthermore, storage experiments revealed that the essential oil-loaded polysaccharide-based high internal phase emulsion showed no visible signs of mold or spoilage after seven months at room temperature, likely reflecting the antibacterial and antioxidant properties of the system.

[0081] Table 3 Antibacterial properties of different samples

[0082]

[0083] Example 5

[0084] This example uses the method of Example 1 to prepare the following eight sets of essential oil-loaded high internal phase emulsions. The specific configurations are shown in Table 4. The oil phase vegetable oil used was peanut oil, and the oil phase also contained 1 mg / mL of β-carotene.

[0085] Table 4

[0086]

[0087] By observing the appearance structure and color of high internal phase emulsion, the stability of the emulsion can be evaluated. Figure 6 As shown, both the carboxymethyl chitosan-based high internal phase emulsion and the carboxymethyl chitosan-based high internal phase emulsion loaded with clove essential oil can be inverted without flowing, have uniform color, stability, and strong gel properties. In contrast, the emulsion using Tween as an emulsifier has a lighter color, exhibits fluidity, and cannot form a self-supporting gel structure.

[0088] The stability of high internal phase emulsions loaded with β-carotene was evaluated under room temperature storage conditions. The concentration of β-carotene in the emulsions was measured after 0, 10, and 75 days of storage to analyze the changes in the stability of β-carotene at different storage times.

[0089] from Figure 7 As can be observed, the β-carotene concentration in the different emulsions decreased to varying degrees with extended storage time. The carboxymethyl chitosan-based high internal phase emulsion showed a relatively small decrease in β-carotene concentration, demonstrating good storage stability. In particular, the 1.5 wt% carboxymethyl chitosan + peanut oil formulation maintained a high β-carotene concentration after 75 days of storage, demonstrating that the carboxymethyl chitosan-based high internal phase emulsion has a protective effect on β-carotene. The high internal phase emulsion system containing clove essential oil exhibited even higher β-carotene stability during room temperature storage. This is presumably due to the antioxidant properties of clove essential oil, which help mitigate the oxidative degradation of β-carotene. This suggests that essential oil-loaded high internal phase emulsions can further enhance the storage stability of β-carotene.

[0090] Example 6

[0091] In this example, a meat mince product was prepared by replacing fat with a high internal phase emulsion loaded with essential oils. The detailed recipe of the meat patties is shown in Table 5 below. The preparation method of the high internal phase emulsion loaded with essential oils was the same as that in Example 1. The aqueous phase was a 0.08 wt% chitosan aqueous solution, and the oil phases were 100% peanut oil (PO) and a clove essential oil-peanut oil mixture with a volume concentration of 10% clove essential oil (CO).

[0092] The specific preparation method is as follows: Use a meat grinder to blend fresh fat and lean meat until a paste forms, then place in a bowl and set aside. Weigh the calculated lean meat, fat / high internal phase emulsion, ice water, and salt separately and stir for 3 minutes. Form the patties into patties in a Petri dish and seal with plastic wrap. The patties should have a mass tolerance of 100.00 ± 2.00 g. Once the water boils, steam for 20 minutes, cool, and set aside.

[0093] Formula: 60% lean meat + 20% fat / HIPEs + 2% salt + 18% ice water. See Table 5 for detailed formula.

[0094] Table 5 Preparation method of meat patties with different high internal phase emulsion replacement ratios

[0095]

[0096] (4) Determination of antioxidant properties

[0097] (1) Determination of primary oxidation

[0098] Weigh 0.3g of cooked meat patties into a centrifuge tube. Add 1.5mL of a mixed solution of isopropyl alcohol and isooctane (mixing ratio of 1:3) and centrifuge at 9000r / min for 10min. Collect 200uL of the supernatant into a brown centrifuge tube. Add 2.8mL of a mixed solution of n-butanol and methanol (mixing ratio of 2:1), then add 15uL of ammonium thiocyanate (mixed 2.99g of ammonium thiocyanate powder with 10mL of pure water) and 15uL of ferrous solution (mixed 0.27g of barium chloride, 0.40g of ferrous sulfate, and 20mL of pure water). Mix well and react in the dark for 20min. Measure the absorbance at a wavelength of 510nm. Draw a standard curve for hydrogen peroxide and calculate the hydroperoxide content in the meat patties.

[0099] (2) Determination of secondary oxidation

[0100] To determine the TBARS value of meat products: Weigh 2 g of cooked meat patties and place them in a centrifuge tube. Add 5 mL of 17.5% trichloroacetic acid (TCA) solution and heat in a 60°C water bath for 30 minutes. Filter the supernatant using filter paper. Mix 2 mL of TCA solution and 1 mL of the supernatant (either filtered supernatant or pure water). Boil in a boiling water bath for 15 minutes and then in an ice water bath for 10 minutes. Measure the absorbance at 532 nm. Develop a standard curve using 1,1,3,3-tetraethoxypropane to calculate the TBARS value of the meat patties.

[0101] Figure 8 Figures A and B show the structural characteristics of meat patties before cooking at different fat replacement ratios for carboxymethyl chitosan-based high internal phase emulsions containing PO and PO+CO, respectively. The blank sample (0% fat replacement) exhibited a pink, meaty texture. However, after adding carboxymethyl chitosan-based high internal phase emulsions, the color gradually changed to white as the replacement ratio increased. The color change was more pronounced in the carboxymethyl chitosan-based high internal phase emulsion containing PO.

[0102] Cooked meat patties with different replacement ratios were observed. Figure 8 C and D show the appearance characteristics of the cooked meat patties prepared with carboxymethyl chitosan-high internal phase emulsion containing PO and carboxymethyl chitosan-high internal phase emulsion containing PO+CO at different substitution ratios. All cooked meat patties were white. However, in the case of the single substitution ratio of PO ( Figure 8 C). When the replacement ratio is 50%, the meat patty shrinks significantly. The shrinkage is more significant than that of the blank meat patty; while when the replacement ratio is 100%, the meat patty has no significant change. This result shows that the cooking loss is the largest when the fat replacement ratio is 50%. The cooking loss is the smallest when the fat replacement ratio is 100%. In the carboxymethyl chitosan-based high internal phase emulsion containing PO+CO mixed replacement group ( Figure 8In D), as the replacement ratio gradually increases, the shrinkage of the meat patty shows a trend of gradually reducing. The juice lost during the cooking process contains small white solid fat particles and transparent oil droplets.

[0103] Vegetable oil can replace fat in meat products to reduce the saturated fatty acid content. However, excessive addition can lead to oxidative rancidity of the fat. This study examined the degree of oxidation in meat patties after fat replacement with a carboxymethyl chitosan-based high internal phase emulsion by measuring primary and secondary oxidation products at different storage times. Peroxide value (POV) and thiobarbituric acid residues (TBARS) were used as indicators to assess changes in primary and secondary oxidation products over different storage times. It was found that at the same storage time, the degree of oxidation decreased with increasing replacement ratios of carboxymethyl chitosan-based high internal phase emulsions. However, at the same replacement ratio, the degree of oxidation increased with extended storage time. Figure 9 Figures A and C show the primary oxidation changes in meat patties with different replacement ratios of carboxymethyl chitosan-based high internal phase emulsion. The POV of the fresh samples was negative, indicating that the fresh meat patties were basically unoxidized. Figure 9 A shows that the oxidation degree of the carboxymethyl chitosan-based high internal phase emulsion with a replacement ratio of 25% PO was the highest after storage for 53 days, while the oxidation degree of each replacement ratio was relatively low after storage for 22 days. Figure 9 C shows that the POV value of the meat patties of the carboxymethyl chitosan-based high internal phase emulsion containing PO+CO increased less, showing more enhanced oxidative stability.

[0104] Secondary oxidation results ( Figure 9 Figures B and D show that the TBARS value of the meat patties gradually increased with storage time. When carboxymethyl chitosan-based high internal phase emulsions replaced fat, the amount of secondary oxidation products decreased, inversely proportional to the replacement ratio. Furthermore, the high internal phase emulsion loaded with clove essential oil further reduced the oxidation rate. Therefore, replacing part of the fat with carboxymethyl chitosan-based high internal phase emulsions loaded with clove essential oil significantly improved the oxidative stability of the meat patties.

[0105] Example 7

[0106] In this example, a mayonnaise-like substance was prepared using a carboxymethyl chitosan-based high internal phase emulsion loaded with essential oils. The specific process was as follows:

[0107] (1) Prepare a carboxymethyl chitosan dispersion using deionized water and control its mass concentration to 0.8% (w / w). Gently stir the solution with a magnetic stirrer for 2 hours at room temperature to ensure that the carboxymethyl chitosan particles are fully dispersed and form a homogeneous system. After stirring, transfer the dispersion to a low-temperature environment at 4°C and refrigerate for at least 12 hours to promote complete hydration of the carboxymethyl chitosan molecular chains. Before using the solution, adjust its pH to 7 using 0.5M hydrochloric acid (HCl);

[0108] (2) An emulsion system was synthesized by a one-step shear dispersion method. The specific operation was as follows: the aqueous phase component (carboxymethyl chitosan dispersion, c = 0.8 wt%, pH 7) was mixed with the oil phase component (pure peanut oil or a clove oil-peanut oil mixture containing 10% clove oil) in a ratio of 1:4, and then subjected to high-intensity shear dispersion treatment at a speed of 10,000 rpm in a high-speed disperser for 30 to 50 seconds.

[0109] (3) Preparation of Mayonnaise-like: A mayonnaise-like mixture was prepared by mixing conventional mayonnaise with the prepared high internal phase emulsion in complementary proportions (see Table 6 below). The total proportion of the two ingredients was always 100%, with the proportion of conventional mayonnaise increasing from 0% to 100% and the proportion of high internal phase emulsion decreasing accordingly.

[0110] Table 6 Mayonnaise ingredient ratio

[0111]

[0112] (4) Use a 5 mL rubber-tipped dropper to draw up a fresh sample. Gently squeeze the dropper to allow approximately 2 mL of sample to flow out naturally and accumulate on the surface of a black plate. After standing for 3 minutes, take a photo to record its spreading morphology. Apply 5 mL of the emulsion evenly to the surface of fresh green vegetable leaves, then stir for 5 seconds and observe the adhesion of the emulsion. Record the overall appearance of the emulsion and lettuce.

[0113] (5) Determine the thermal stability of the mayonnaise-like product with a slight modification: Place the mayonnaise in a water bath at 80°C for 30 min and then centrifuge at 5000 rpm for 10 min to separate the oil phase.

[0114] The thermal stability of the emulsion was calculated using the formula.

[0115]

[0116] Where: Y is thermal stability; m0 is the initial sample mass; m1 is the mass of the centrifuged oil phase.

[0117] like Figure 10 As shown in the figure, this study successfully prepared a carboxymethyl chitosan-based high internal phase emulsion and constructed low-cholesterol mayonnaise-like systems with varying emulsion replacement amounts. The mayonnaise-like system exhibited a uniform semi-solid paste-like consistency, with a dense emulsion distribution and no oil rings. The surface was smooth and free of stratification, and the color was light milky yellow, meeting the expected characteristics.

[0118] Depend on Figure 11It can be seen that when about 2.5 ml of mayonnaise-like emulsion samples were squeezed out of the small tube, the samples were all viscoelastic emulsions with support force, and they all maintained their three-dimensional shape without deformation. This is because the interaction force between the droplets, the emulsion exhibits the properties of a non-Newtonian fluid and a solid-like state, and the free movement of the droplets is restricted. In order to simulate the consumption scenario of mayonnaise in daily life, the adhesion of the mayonnaise-like substance was measured. By mixing and stirring the vegetable leaves and the mayonnaise-like substance, the actual adhesion and dispersion of the mayonnaise-like substance were observed. After manually stirring for 5 seconds, the adhesion of the mayonnaise-like substance on the lettuce was measured. Adhesion refers to the resistance parameter (viscosity) to sample flow during extrusion. A comparison revealed that the viscosity changes of mayonnaise-like products prepared with pure peanut oil and a peanut oil / clove essential oil blend were similar. When the emulsion addition level was less than 50% (M0, M20, and M40), the mayonnaise-like adhered to lettuce leaves. However, when the emulsion ratio exceeded 50% (M60, M80, and M100), the mayonnaise-like adhesion decreased significantly. This is likely because a large substitution ratio enhances the oil-dominated fluidity, disrupting the three-dimensional network structure and weakening the interactions between droplets and interfacial adsorption capacity.

[0119] Depend on Figure 12 Mayonnaise-like products with varying emulsion addition levels exhibited thermal stability exceeding 97% after being heated in a water bath at 80°C for 30 minutes and then centrifuged at 5000 rpm for 10 minutes. The high stability of the mayonnaise-like products is related in part to their dense three-dimensional internal network structure and in part to the addition of clove essential oil. The addition of the essential oil increases the viscosity and elastic modulus of the system, thereby slowing the movement of emulsion droplets, inhibiting droplet aggregation, and improving the stability of the mayonnaise-like products.

[0120] As can be seen from the above examples, the preparation method of the present invention is simple to operate and environmentally friendly. The high internal phase emulsion loaded with essential oil prepared from single polysaccharide or polysaccharide composite particles under different pH conditions is a physical gel, does not produce trans fatty acids, has good safety, high stability, strong plasticity, and has good thermal stability and temperature responsiveness. During the five-month storage process, no visible mildew or corruption occurs, no oil leakage or demulsification occurs, its structure is very stable, and the emulsification stability of the polysaccharide and the antibacterial and antioxidant properties of the essential oil are fully utilized. The high internal phase emulsion loaded with essential oil has good application potential and development value, and can be used in the fields of food, medicine, chemical industry, and bioengineering materials.

[0121] The above description is only a preferred embodiment of the present invention and does not limit the implementation mode and protection scope of the present invention. For those skilled in the art, it should be aware that all solutions obtained by equivalent substitutions and obvious changes made using the description and illustrations of the present invention should be included in the protection scope of the present invention.

Claims

1. A polysaccharide-based high internal phase emulsion system loaded with essential oils, characterized in that: Prepared by the following method: 1) preparing an aqueous solution containing a polysaccharide substance and adjusting the pH as the aqueous phase; 2) Mixing essential oils and vegetable oils as the oil phase; 3) mixing the aqueous phase prepared in step 1) and the oil phase prepared in step 2) to obtain the essential oil-loaded polysaccharide-based high internal phase emulsion system; Wherein, the essential oil is selected from at least one of lemon essential oil, clove essential oil and perilla essential oil.

2. The polysaccharide-based high internal phase emulsion system according to claim 1, characterized in that: The volume content of the essential oil in the oil phase is 5%-100%.

3. The polysaccharide-based high internal phase emulsion system according to claim 1, characterized in that: The vegetable oil is selected from at least one of peanut oil, rapeseed oil, soybean oil, palm oil, linseed oil, castor oil and blended oil.

4. The polysaccharide-based high internal phase emulsion system according to claim 1, characterized in that: The polysaccharide substance is selected from at least one of chitosan hydrochloride, carboxymethyl chitosan, sodium carboxymethyl cellulose, pectin and sodium alginate.

5. The polysaccharide-based high internal phase emulsion system according to claim 1, characterized in that: The mass concentration of the aqueous solution of the polysaccharide substance in the aqueous phase is 0.05-3.0%.

6. The polysaccharide-based high internal phase emulsion system according to claim 1, characterized in that: When the aqueous phase is a composite particle dispersion of chitosan hydrochloride and carboxymethyl chitosan, the pH of the aqueous phase solution needs to be adjusted to 6.0-6.

7.

7. The polysaccharide-based high internal phase emulsion system according to claim 1, characterized in that: The mixing condition is shearing for 20s to 90s at 10000rpm to 12000rpm.

8. Use of the essential oil-loaded polysaccharide-based high internal phase emulsion system according to any one of claims 1 to 7 in the preparation of products loaded with functional active ingredients.

9. Use of the essential oil-loaded polysaccharide-based high internal phase emulsion system according to any one of claims 1 to 7 in the preparation of minced meat products.

10. Use of the essential oil-loaded polysaccharide-based high internal phase emulsion system according to any one of claims 1 to 7 in the preparation of mayonnaise.

Images