Composite coffee essential oil high internal phase emulsion gel

Abstract

The invention provides compound coffee essential oil high internal phase emulsion gel, and belongs to the field of plant essential oil processing. The gel comprises a water phase and an oil phase, the water phase is a microcapsule, and the oil phase is lipidosome containing coffee essential oil; the oil phase accounts for 72-90% of the total volume of the system; the microcapsule is prepared by mixing a core material, a wall material and an emulsifier in water and then carrying out ultrasonic treatment, the preparation method of the lipidosome comprises the following steps: dissolving coffee essential oil, soybean lecithin and cholesterol in a solvent, performing rotary evaporation to obtain a film, adding the film into a buffer solution, and finally performing ultrasonic hydration to obtain the lipidosome. The invention establishes a steady-state method of the coffee essential oil, so that the coffee essential oil has certain quality and price advantages compared with products in the current market.

Description

Technical Field

[0001] The invention relates to the field of plant essential oil processing, in particular to a composite coffee essential oil high internal phase emulsion gel. Background Art

[0002] Coffee is a popular beverage in the world and is commonly grown in tropical and subtropical regions. Currently, coffee is mainly grown in Yunnan, Hainan and other regions in my country. It is a unique agricultural and food resource. Coffee essential oil is an essential oil extracted from coffee, accounting for about 10% of the weight of coffee. It is a natural cosmetic raw material with multiple functional activities. For example, it has antioxidant, antibacterial and anti-aging capabilities, and can also help improve skin condition. Studies have shown that it is beneficial to improve enlarged pores, reduce acne, and improve skin inflammation.

[0003] Because coffee essential oil has unique functional characteristics, it is loved by consumers as a cosmetic raw material and has a broad market prospect. However, there are still some difficulties in utilizing coffee essential oil. For example, as an oily substance, coffee essential oil is not only easily restricted in its scope of application, but also prone to decomposition and deterioration during processing and storage, and has a high transportation cost. In addition, the bioavailability of coffee essential oil remains to be improved. The above many factors limit the application and promotion of coffee essential oil. Therefore, it is of great significance to find a method to improve the bioavailability and stability of coffee essential oil and to improve its scope of application.

[0004] In recent years, high internal phase emulsions have been widely used in the cosmetics field. High internal phase emulsions refer to emulsions in which the volume of the oil phase accounts for more than 74%. Compared with traditional emulsions, they have unique physical properties. They not only have a large interface area, but also have adjustable flow properties. These physical properties give high internal phase emulsions higher loading capacity, stability and controllability. However, the performance improvement of high internal phase emulsions alone is limited, and how to further improve the various properties of high internal phase emulsions has become the focus of research. Summary of the invention

[0005] In view of the above problems existing in the prior art, the present invention provides a composite coffee essential oil high internal phase emulsion gel. The present invention establishes a stabilization method of coffee essential oil, which has certain quality and price advantages compared with the products currently on the market.

[0006] The technical solution of the present invention is as follows:

[0007] A composite coffee essential oil high internal phase emulsion gel comprises a water phase and an oil phase, wherein the water phase is a microcapsule and the oil phase is a liposome containing coffee essential oil; the oil phase accounts for 72-90% of the total volume of the system.

[0008] Furthermore, the microcapsules are prepared by mixing a core material, a wall material and an emulsifier in water and then subjecting them to ultrasonic treatment; wherein the mass ratio of the core material to the wall material is 1:8-1:12.

[0009] Preferably, the core material includes any one of caffeic acid, caffeine and chlorogenic acid.

[0010] Preferably, the wall material includes any one of hydroxypropyl-β-cyclodextrin and β-cyclodextrin; the concentration of the wall material in water is 2-6%.

[0011] Preferably, the emulsifier includes any one of whey protein and zein; the concentration of the emulsifier in water is 2-6%.

[0012] Preferably, the ultrasonic power during the preparation of the microcapsules is 300-500 W, the ultrasonic time is 60-120 min, and the ultrasonic temperature is 40-60° C.

[0013] Furthermore, the liposome preparation method is as follows: coffee essential oil, soybean lecithin and cholesterol are dissolved in a solvent, and then subjected to rotary evaporation to obtain a film, and then added to a buffer solution, and finally prepared by ultrasonic hydration;

[0014] The concentration of coffee essential oil is 0.2-0.8%, the concentration of soybean lecithin is 1-4%, and the concentration of cholesterol is 0.25-1%.

[0015] Preferably, the solvent includes any one of anhydrous ethanol, methanol and isopropanol.

[0016] Preferably, the buffer solution is a phosphate buffer solution containing polyvinyl pyrrolidone, and the volume ratio of the buffer solution to the solvent is 1:0.5-1:1.5.

[0017] Preferably, the concentration of the phosphate buffer solution is 0.01-0.02 mol / L, wherein the concentration of polyvinyl pyrrolidone is 0.1-0.4%, and the pH of the phosphate buffer solution is 6-7.

[0018] Preferably, the temperature during rotary evaporation is 40-60°C and the speed is 40-70rpm.

[0019] Preferably, the ultrasonic power during the preparation of the liposomes is 300-500 W, the ultrasonic time is 15-45 min, and the ultrasonic temperature is 30-50° C.

[0020] Furthermore, the water phase and the oil phase are mixed and fully homogenized and emulsified to obtain the composite high internal phase emulsion gel.

[0021] Preferably, the homogenization emulsification rate is 10000-20000 rpm / min, the temperature is 50-70° C., and the time is 2-6 min.

[0022] In the above technical solution, caffeic acid, caffeine, chlorogenic acid or other active ingredients mainly play the role of enhancing the activity of coffee essential oil.

[0023] Hydroxypropyl-β-cyclodextrin and β-cyclodextrin are used as microcapsule wall materials, and whey protein and zein are used as emulsifiers of the emulsion.

[0024] The concentration of the wall material and the emulsifier refers to the concentration of the wall material or the emulsifier after being dissolved in water, such as 1g of hydroxypropyl-β-cyclodextrin dissolved in 20mL of water, the concentration is 5%, and 0.4g of whey protein dissolved in 20mL of water, the concentration is 2%.

[0025] The concentration of the coffee essential oil is in volume percentage; the concentration of the soybean lecithin and cholesterol is in g / mL percentage.

[0026] The beneficial technical effects of the present invention are:

[0027] 1. The present invention is the first to use microcapsule technology and liposome technology to prepare high internal phase emulsion technology for the stabilization study of coffee essential oil. Caffeic acid and coffee essential oil are combined in the form of microcapsules and liposomes respectively using high internal phase emulsions. The two components play a synergistic role, improving the sample loading, bioavailability and stability of coffee essential oil, which is the key and prerequisite for the further application of coffee essential oil.

[0028] 2. The main components of high internal phase emulsion are water phase and oil phase, and the various properties of high internal phase emulsion can be improved by modifying the water phase. The present invention uses microcapsule technology to modify the water phase, not only the core material of the microcapsule can further increase the various functional capabilities of coffee essential oil, but also the wall material of the microcapsule can further enhance the stability of the high internal phase emulsion, and together play a synergistic role.

[0029] 3. The present invention also modifies the oil phase of the high internal phase emulsion and uses liposome technology to prepare the oil phase of the high internal phase emulsion, which can improve the stability of the high internal phase emulsion and enhance the efficacy of its active ingredients.

[0030] 4. The present invention uses hydroxypropyl-β-cyclodextrin as the wall material of the microcapsule for the aqueous phase preparation of the high internal phase emulsion, and PVP (polyvinyl pyrrolidone) as a liposome additive for the oil phase preparation of the high internal phase emulsion, thereby improving the loading capacity, stability and bioavailability of the high internal phase emulsion loaded with coffee essential oil.

[0031] 5. The composite high internal phase emulsion gel prepared by the present invention further expands the application scope of coffee essential oil and reduces transportation costs. Its preparation process is simple and fast, and there are no complex preparation conditions such as high temperature and high pressure in the production process. The energy consumption cost of the preparation process is low, the safety is good, and it is green and environmentally friendly, which is suitable for large-scale industrial production.

[0032] 6. The composite coffee essential oil high internal phase emulsion gel prepared by the present invention is in a white gel emulsion state, can be taken orally or applied externally, is easy to use and store, and has no toxic effect on the body. The combination of the two methods can play a role in whitening and regulating the skin. DETAILED DESCRIPTION

[0033] The present invention is described in detail below in conjunction with the embodiments. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all 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.

[0034] Embodiment 1:

[0035] This example investigates the effect of wall material concentration on the encapsulation effect in the optimization of water phase modification of high internal phase emulsions using microencapsulation technology.

[0036] The effect of the amount of hydroxypropyl-β-cyclodextrin added on the microcapsule embedding effect was studied. 2, 3, 4, 5, and 6 g of hydroxypropyl-β-cyclodextrin were weighed, and then 2 g of whey protein and 100 mL of ultrapure water were added, and ultrasonic treatment was performed at an ultrasonic power of 300 W and an ultrasonic temperature of 40°C for 30 min. After the treatment, caffeic acid was added as the core material according to a core-wall ratio of 1:10, and then ultrasonic treatment was performed at an ultrasonic power of 300 W and an ultrasonic temperature of 40°C for 30 min. The solution was completely dissolved to obtain a microcapsule solution. The embedding effect was evaluated by the embedding rate, and the results are shown in Table 1.

[0037] Table 1 Effect of wall material concentration on embedding effect

[0038]

[0039]

[0040] The results show that with the increase of hydroxypropyl-β-cyclodextrin wall material concentration, the embedding effect of caffeic acid shows an upward trend, but when the hydroxypropyl-β-cyclodextrin wall material concentration is 5% and 6%, the embedding rate is not much different. Considering comprehensively, the hydroxypropyl-β-cyclodextrin wall material concentration is selected to be 5%.

[0041] Embodiment 2:

[0042] This example investigates the effect of the core-to-wall ratio on the encapsulation effect in the optimization of the aqueous phase modification of high internal phase emulsions using microencapsulation technology.

[0043] To study the effect of core-to-wall ratio on microcapsule embedding effect, 5 g of hydroxypropyl-β-cyclodextrin was weighed, followed by addition of 2 g of whey protein and 100 mL of ultrapure water, and ultrasonic treatment was performed at an ultrasonic power of 300 W and an ultrasonic temperature of 40°C for 30 min. After treatment, caffeic acid was added as core material according to core-to-wall ratios of 1:8, 1:9, 1:10, 1:11, and 1:12, and then ultrasonic treatment was performed at an ultrasonic power of 300 W and an ultrasonic temperature of 40°C for 30 min, and the solution was completely dissolved to obtain microcapsule solution. The embedding effect was evaluated by the embedding rate, and the results are shown in Table 2.

[0044] Table 2 Effect of core-to-wall ratio on embedding effect

[0045]

[0046]

[0047] The results show that with the increase of core-to-wall ratio, the embedding rate shows a trend of first increasing and then decreasing. This may be because when the core material continues to increase, the core material is not completely embedded, and a large amount of microcapsules adhere to the wall, resulting in a decrease in the embedding rate. Considering all factors, the core-to-wall ratio is selected as 1:11.

[0048] Embodiment 3:

[0049] This example investigates the effect of ultrasound power on the embedding effect in the optimization of water phase modification of high internal phase emulsion using microencapsulation technology.

[0050] To study the effect of ultrasonic power on the microcapsule embedding effect, 5 g of hydroxypropyl-β-cyclodextrin was weighed, followed by the addition of 2 g of whey protein and 100 mL of ultrapure water, and ultrasonic treatment was performed at an ultrasonic power of 300 W and an ultrasonic temperature of 40 ° C for 30 min. After the treatment, caffeic acid was added as the core material according to a core-wall ratio of 1:11, and then ultrasonic treatment was performed at ultrasonic powers of 300, 350, 400, 450, and 500 W and an ultrasonic temperature of 40 ° C for 30 min, and the solution was completely dissolved to obtain a microcapsule solution. The embedding effect was evaluated by the embedding rate, and the results are shown in Table 3.

[0051] Table 3 Effect of ultrasonic power on embedding effect

[0052] Ultrasonic power (W) Embedding rate (%) 300 80.12±0.91 350 81.98±1.25 400 83.35±1.87 450 82.46±1.09 500 78.56±1.33

[0053] The results showed that with the increase of ultrasonic power, the embedding rate showed a trend of first rising and then falling. When the ultrasonic power was 400 W, the embedding rate reached the highest 83.35%. Taking comprehensive consideration, the ultrasonic power was selected as 400 W.

[0054] Embodiment 4:

[0055] This example investigates the effect of ultrasound time on the embedding effect in the optimization of water phase modification of high internal phase emulsion using microencapsulation technology.

[0056] To study the effect of ultrasonic time on the microcapsule embedding effect, 5g of hydroxypropyl-β-cyclodextrin was weighed, followed by the addition of 2g of whey protein and 100mL of ultrapure water, and the ultrasonic treatment was carried out at an ultrasonic power of 300W and an ultrasonic temperature of 40°C for 30min. After the treatment, caffeic acid was added as the core material according to a core-to-wall ratio of 1:11, and then the ultrasonic treatment was carried out at an ultrasonic power of 400W and an ultrasonic temperature of 40°C for 30, 40, 50, and 60min, respectively, and the solution was completely dissolved to obtain a microcapsule solution. The embedding effect was evaluated by the embedding rate, and the results are shown in Table 4.

[0057] Table 4 Effect of ultrasound time on embedding effect

[0058] Ultrasonic time (min) Embedding rate (%) 30 83.35±0.87 40 85.67±1.72 50 87.95±1.62 60 85.45±1.33

[0059] The results show that with the increase of ultrasonic time, the embedding rate shows a trend of first increasing and then decreasing, which may be because too long ultrasonic time will have a destructive effect on the wall material. Taking comprehensive considerations, the ultrasonic time is selected to be 50 minutes.

[0060] Embodiment 5:

[0061] This example investigates the effect of coffee essential oil concentration on the encapsulation efficiency in the optimization of oil phase modification of high internal phase emulsions using liposome technology.

[0062] Weigh 0.4g soybean lecithin and 0.1g cholesterol, add 40mL anhydrous ethanol, then add 0.08, 0.16, 0.24, 0.32mL coffee essential oil respectively, mix well, use rotary evaporator to remove anhydrous ethanol at 60rpm at 40℃ to obtain film, then add 40mL phosphate buffer solution (0.01mol / L, pH=7) containing 0.1% PVP, ultrasonic assisted hydration treatment at ultrasonic power of 300W and ultrasonic temperature of 40℃ for 15min, filter to obtain liposome solution after hydration. The embedding effect is evaluated by embedding rate, and the results are shown in Table 5.

[0063] Table 5 Effect of coffee essential oil concentration on encapsulation effect

[0064] Coffee essential oil concentration (%) Embedding rate (%) 0.2 62.26±2.45 0.4 68.87±2.71 0.6 59.33±2.62 0.8 57.23±3.12

[0065] The results showed that as the concentration of coffee essential oil increased, the embedding rate showed a trend of increasing and then decreasing. This may be because it is difficult for liposomes to embed coffee essential oil at low concentrations, resulting in a low embedding rate; but when the concentration of coffee essential oil exceeds the embedding capacity of liposomes, the excess coffee essential oil will cause the embedding rate to decrease. Considering all factors, the coffee essential oil concentration was selected to be 0.4%.

[0066] Embodiment 6:

[0067] This example investigates the effect of the mass ratio of soybean lecithin to cholesterol on the encapsulation efficiency in the optimization of the oil phase modification of a high internal phase emulsion using liposome technology.

[0068] Weigh 0.4g of soybean lecithin, weigh cholesterol according to the mass ratio of soybean lecithin to cholesterol of 2:1, 3:1, 4:1, and 5:1, add 40mL of anhydrous ethanol, then add 0.16mL of coffee essential oil, mix well, and remove anhydrous ethanol by rotary evaporation at 60rpm at 40°C to obtain a film, then add 40mL of phosphate buffer solution (0.01mol / L, pH=7) containing 0.1% PVP, and ultrasonically assist hydration for 15min at an ultrasonic power of 300W and an ultrasonic temperature of 40°C. After hydration, filter to obtain a liposome solution. The embedding effect was evaluated by the embedding rate, and the results are shown in Table 6.

[0069] Table 6 Effect of the mass ratio of soybean lecithin to cholesterol on the encapsulation effect

[0070] Mass ratio of soybean lecithin to cholesterol Embedding rate (%) 2:1 61.45±2.12 3:1 68.22±1.93 4:1 68.87±2.71 5:1 57.78±1.87

[0071] The results show that as the mass ratio of soybean lecithin to cholesterol increases, the embedding rate shows a trend of increasing and then decreasing. This may be because although increasing cholesterol can maintain the mobile phase and stability of the phospholipid bilayer, when the cholesterol ratio exceeds a certain limit, it will damage the membrane stability and reduce its embedding rate. Taking all factors into consideration, the mass ratio of soybean lecithin to cholesterol is selected to be 4:1.

[0072] Embodiment 7:

[0073] This example investigates the effect of ultrasound power on the embedding effect in the optimization of oil phase modification of high internal phase emulsion using liposome technology.

[0074] Weigh 0.4g soybean lecithin, 0.1g cholesterol, add 40mL anhydrous ethanol, then add 0.16mL coffee essential oil, mix well, use rotary evaporator to remove anhydrous ethanol at 60rpm at 40℃ to obtain film, then add 40mL phosphate buffer solution (0.01mol / L, pH=7) containing 0.1% PVP, respectively, ultrasonic power of 300, 350, 400, 450, 500W, ultrasonic temperature of 40℃ for 15min, filter after hydration to obtain liposome solution. The embedding effect was evaluated by embedding rate, and the results are shown in Table 7.

[0075] Table 7 Effect of ultrasonic power on embedding effect

[0076]

[0077]

[0078] The results show that with the increase of ultrasonic power, the embedding rate shows a trend of first increasing and then decreasing. This may be because too high ultrasonic power will also destroy the lipid bilayer membrane of liposomes and cause the leakage of coffee essential oil. After comprehensive consideration, the ultrasonic power is selected to be 450W.

[0079] Embodiment 8:

[0080] This example investigates the effect of hydration time on the embedding effect in the optimization of oil phase modification of high internal phase emulsion using liposome technology.

[0081] Weigh 0.4g soybean lecithin, 0.1g cholesterol, add 40mL anhydrous ethanol, then add 0.16mL coffee essential oil, mix well, use a rotary evaporator to remove anhydrous ethanol at 60rpm at 40°C to obtain a film, then add 40mL phosphate buffer solution (0.01mol / L, pH=7) containing 0.1% PVP, and perform ultrasonic assisted hydration treatment at an ultrasonic power of 450W and an ultrasonic temperature of 40°C for 15, 30, 45, and 60min, respectively. After hydration, filter to obtain a liposome solution. The embedding effect was evaluated by the embedding rate, and the results are shown in Table 8.

[0082] Table 8 Effect of hydration time on embedding effect

[0083]

[0084]

[0085] The results showed that with the increase of hydration time, the embedding rate showed a trend of increasing first and then decreasing. This may be because the appropriate increase of ultrasonic hydration time is conducive to the formation of liposomes, but if the ultrasonic hydration time is too long, the ultrasonic treatment may destroy the liposomes and cause the leakage of coffee essential oil. Considering comprehensively, the hydration time was selected as 45 minutes.

[0086] Embodiment 9:

[0087] This embodiment provides a composite coffee essential oil high internal phase emulsion gel and a preparation method thereof, and the specific steps are as follows:

[0088] (1) Weigh 1 g of hydroxypropyl-β-cyclodextrin, then add 1 g of whey protein and 50 mL of ultrapure water, and ultrasonically treat for 30 min at an ultrasonic power of 300 W and an ultrasonic temperature of 40° C. After the treatment, add caffeic acid as a core material according to a core-to-wall ratio of 1:8, and then ultrasonically treat for 30 min at an ultrasonic power of 400 W and an ultrasonic temperature of 40° C., wait for the solution to be completely dissolved, and obtain a microcapsule solution as a high internal phase emulsion aqueous phase for use.

[0089] (2) Weigh 0.1 g of soybean lecithin and 0.025 g of cholesterol, add 10 mL of anhydrous ethanol, and then add 0.02 mL of coffee essential oil. After mixing, use a rotary evaporator to remove the anhydrous ethanol at 40 rpm at 40 ° C to obtain a thin film. Then add 10 mL of phosphate buffer solution (0.01 mol / L, pH = 7) containing 0.1% PVP, and ultrasonically assisted hydration treatment at an ultrasonic power of 300 W and an ultrasonic temperature of 30 ° C for 15 min. After hydration is completed, filter to obtain the liposome solution high internal phase emulsion oil phase for use.

[0090] (3) 1 mL of the microcapsule solution was used as the aqueous phase, and high-speed shearing was performed at 50° C. and 10,000 rpm / min for 2 min, followed by the slow addition of 3 mL of the liposome solution, followed by homogenization under the same conditions, and then allowed to stand at room temperature to obtain a coffee essential oil multiple composite high internal phase emulsion gel.

[0091] Embodiment 10:

[0092] This embodiment provides a composite coffee essential oil high internal phase emulsion gel and a preparation method thereof, and the specific steps are as follows:

[0093] (1) Weigh 5 g of hydroxypropyl-β-cyclodextrin, then add 5 g of whey protein and 125 mL of ultrapure water, and ultrasonically treat for 45 min at an ultrasonic power of 400 W and an ultrasonic temperature of 50 ° C. After the treatment, caffeic acid is added as a core material according to a core-to-wall ratio of 1:10, and then ultrasonically treat for 45 min at an ultrasonic power of 400 W and an ultrasonic temperature of 50 ° C., wait for the solution to be completely dissolved, and obtain a microcapsule solution as a high internal phase emulsion aqueous phase for use.

[0094] (2) Weigh 0.4 g of soybean lecithin and 0.1 g of cholesterol, add 20 mL of anhydrous ethanol, and then add 0.12 mL of coffee essential oil. After mixing, use a rotary evaporator to remove the anhydrous ethanol at 60 rpm at 50°C to obtain a thin film. Then add 20 mL of phosphate buffer solution (0.01 mol / L, pH = 7) containing 0.2% PVP, and ultrasonically assisted hydration treatment at an ultrasonic power of 400 W and an ultrasonic temperature of 40°C for 30 min. After hydration is completed, filter to obtain the liposome solution high internal phase emulsion oil phase for use.

[0095] (3) 5 mL of microcapsule solution was used as the aqueous phase, and high-speed shearing was performed at 60° C. and 15,000 rpm / min for 4 min, followed by slow addition of 20 mL of liposome solution, followed by homogenization under the same conditions, and then left at room temperature to obtain a coffee essential oil multiple composite high internal phase emulsion gel.

[0096] Embodiment 11:

[0097] This embodiment provides a composite coffee essential oil high internal phase emulsion gel and a preparation method thereof, and the specific steps are as follows:

[0098] (1) Weigh 10 g of hydroxypropyl-β-cyclodextrin, then add 10 g of whey protein and 200 mL of ultrapure water, and perform ultrasonic treatment for 60 min at an ultrasonic power of 500 W and an ultrasonic temperature of 60 ° C. After the treatment is completed, caffeic acid is added as a core material according to a core-to-wall ratio of 1:12, and then ultrasonic treatment is performed for 60 min at an ultrasonic power of 500 W and an ultrasonic temperature of 60 ° C. Wait for the solution to be completely dissolved, and obtain a microcapsule solution as a high internal phase emulsion aqueous phase for use.

[0099] (2) Weigh 0.8 g of soybean lecithin and 0.2 g of cholesterol, add 20 mL of anhydrous ethanol, and then add 0.16 mL of coffee essential oil. After mixing, use a rotary evaporator to remove the anhydrous ethanol at 70 rpm at 60°C to obtain a thin film. Then add 20 mL of phosphate buffer solution (0.01 mol / L, pH = 7) containing 0.4% PVP, and ultrasonically assisted hydration treatment at an ultrasonic power of 500 W and an ultrasonic temperature of 50°C for 45 min. After hydration is completed, filter to obtain the liposome solution high internal phase emulsion oil phase for use.

[0100] (3) 10 mL of the microcapsule solution was used as the aqueous phase, and high-speed shearing was performed at 70° C. and 20,000 rpm / min for 6 min, followed by the slow addition of 90 mL of the liposome solution, followed by homogenization under the same conditions, and then allowed to stand at room temperature to obtain a coffee essential oil multiple composite high internal phase emulsion gel.

[0101] The high internal phase emulsions prepared in Examples 9-11 are in gel form, wherein the internal phase, ie, the dispersed phase, of the high internal phase emulsions is an oil phase, and the external phase, ie, the continuous phase, is an aqueous phase.

[0102] Test Example 1: Material Performance Evaluation of High Internal Phase Emulsion

[0103] Sample 1: Ordinary high internal phase emulsion without microcapsule and liposome technology modification:

[0104] Weigh 2 g of whey protein and 100 mL of water, and perform ultrasonic treatment for 30 min at an ultrasonic power of 300 W and an ultrasonic temperature of 40° C. After the treatment, use it as the aqueous phase of the high internal phase emulsion for later use.

[0105] 5 mL of water phase was subjected to high-speed shearing at 50° C. and 10,000 rpm / min for 3 min, and then 15 mL of coffee essential oil was slowly added, followed by homogenization under the same conditions and then standing at room temperature to obtain sample 1.

[0106] Sample 2: The aqueous phase was modified with microcapsules, and the oil phase was not modified with liposomes:

[0107] Weigh 5 g of hydroxypropyl-β-cyclodextrin, then add 2 g of whey protein and 100 mL of water, and ultrasonically treat for 30 min at an ultrasonic power of 300 W and an ultrasonic temperature of 40°C. After the treatment, add caffeic acid as the core material according to a core-wall ratio of 1:11, and then ultrasonically treat for 50 min at an ultrasonic power of 400 W and an ultrasonic temperature of 40°C. Wait for the solution to be completely dissolved to obtain a microcapsule solution for use as the aqueous phase of the high internal phase emulsion.

[0108] 5 mL of microcapsule solution was used as the aqueous phase and high-speed sheared at 50° C. and 10,000 rpm / min for 3 min, and then 15 mL of coffee essential oil was slowly added. The mixture was then homogenized under the same conditions and then allowed to stand at room temperature to obtain sample 2.

[0109] Sample 3: No microcapsules to modify the water phase, but liposome technology to modify the oil phase:

[0110] Weigh 2 g of whey protein and 100 mL of water, and perform ultrasonic treatment for 30 min at an ultrasonic power of 300 W and an ultrasonic temperature of 40° C. After the treatment, use it as the aqueous phase of the high internal phase emulsion for later use.

[0111] Weigh 0.4g soybean lecithin, 0.1g cholesterol, add 40mL anhydrous ethanol, then add 0.16mL coffee essential oil, mix well, and use a rotary evaporator to remove anhydrous ethanol at 60rpm at 40°C to obtain a thin film, then add 40mL of phosphate buffer solution (0.01mol / L, pH=7) containing 0.1% PVP, and ultrasonically assisted hydration treatment for 45min at an ultrasonic power of 450W and an ultrasonic temperature of 40°C. After hydration, filter to obtain the liposome solution high internal phase emulsion oil phase for use.

[0112] 5 mL of aqueous phase was subjected to high-speed shearing at 50° C. and 10,000 rpm / min for 3 min, and then 15 mL of liposome solution was slowly added, followed by homogenization under the same conditions and then standing at room temperature to obtain sample 3.

[0113] Sample 4: The aqueous phase and oil phase were modified by microcapsules and liposomes respectively:

[0114] Weigh 5 g of hydroxypropyl-β-cyclodextrin, then add 2 g of whey protein and 100 mL of water, and ultrasonically treat for 30 min at an ultrasonic power of 300 W and an ultrasonic temperature of 40°C. After the treatment, add caffeic acid as the core material according to a core-wall ratio of 1:11, and then ultrasonically treat for 50 min at an ultrasonic power of 400 W and an ultrasonic temperature of 40°C. Wait for the solution to be completely dissolved to obtain a microcapsule solution for use as the aqueous phase of the high internal phase emulsion.

[0115] Weigh 0.4g soybean lecithin, 0.1g cholesterol, add 40mL anhydrous ethanol, then add 0.16mL coffee essential oil, mix well, and use a rotary evaporator to remove anhydrous ethanol at 60rpm at 40°C to obtain a thin film, then add 40mL of phosphate buffer solution (0.01mol / L, pH=7) containing 0.1% PVP, and ultrasonically assisted hydration treatment for 45min at an ultrasonic power of 450W and an ultrasonic temperature of 40°C. After hydration, filter to obtain the liposome solution high internal phase emulsion oil phase for use.

[0116] 5 mL of microcapsule solution was used as the aqueous phase and high-speed sheared at 50° C. and 10,000 rpm / min for 3 min. Then 15 mL of liposome solution was slowly added, and then homogenized under the same conditions and then left at room temperature to obtain sample 4.

[0117] The particle size distribution of the above four samples was measured using a laser particle size analyzer, and the particle size distribution of the four samples was compared. The results are shown in Table 9.

[0118] Table 9 Particle size analysis

[0119]

[0120]

[0121] The performance of high internal phase emulsion was evaluated by particle size, Zeta potential and PDI. The results showed that both microcapsules and liposomes can reduce the emulsion particle size, increase the Zeta potential and reduce the PDI value. The effect of the emulsion after the two are combined is better than that of a single technology. This shows that microcapsules and liposomes can modify the water phase and oil phase of the high internal phase emulsion respectively, thereby improving the strength of the high internal phase emulsion material itself.

[0122] Test Example 2: Evaluation of the embedding efficiency of high internal phase emulsion.

[0123] Sample 1, sample 2, sample 3, and sample 4 were prepared as shown in Test Example 1. The method for determining the embedding rate was the method used in "Effects of different wall materials on the microstructure and thermal stability of green coffee oil microcapsules" (Mu Jingyi et al., Journal of Tropical Crops, Issue 3, 2023, pp. 647-660), and the results are shown in Table 10.

[0124] Table 10 Evaluation of embedding efficiency of high internal phase emulsion

[0125] sample Embedding rate (%) Sample 1 65.24±2.72 Sample 2 76.72±1.65 Sample 3 78.28±2.29 Sample 4 88.37±1.34

[0126] The results show that microcapsule and liposome technology can increase the embedding rate of samples. At the same time, the embedding rate of samples after the combination of the two technologies reaches a maximum of 88.37%, indicating that microcapsule and liposome technology can modify the water phase and oil phase of high internal phase emulsion respectively, thereby improving the embedding capacity of high internal phase emulsion materials.

[0127] Test Example 3: Evaluation of thermal stability of high internal phase emulsion

[0128] Sample 1, Sample 2, Sample 3, and Sample 4 were prepared as shown in Test Example 1, and Sample 5 was coffee essential oil.

[0129] The above samples were heated in an oil bath at 180°C for 2 hours. The acid value was used as an evaluation index of thermal stability to compare the thermal stabilities of the five samples. The results are shown in Table 11.

[0130] Table 11 Thermal stability evaluation

[0131]

[0132] The thermal stability of high internal phase emulsion was evaluated by the acid value before and after heating. The results showed that the thermal stability of coffee essential oil was poor, and the acid value increased significantly after heating. In addition, microcapsule technology and liposome technology can improve the thermal stability of high internal phase emulsion respectively, and the combination of the two technologies can more effectively reduce the acid value. Therefore, microcapsule and liposome technologies can modify the water phase and oil phase of high internal phase emulsion respectively, and they have a synergistic effect, which improves the thermal stability of high internal phase emulsion.

[0133] Test Example 4: Comparison of Antioxidant Effects of High Internal Phase Emulsions

[0134] Sample 1, Sample 2, Sample 3, and Sample 4 were prepared as shown in Test Example 1.

[0135] The same volume of the above samples was measured and their antioxidant capacity was evaluated using DPPH free radicals at the same concentration. The results are shown in Table 12.

[0136] Table 12 Evaluation of antioxidant capacity

[0137]

[0138] The results show that different samples have different scavenging abilities for the same concentration of DPPH free radicals at the same concentration. First, microencapsulation technology can improve the antioxidant capacity of high internal phase emulsions, while liposome technology has limited antioxidant capacity; and after the combination of microencapsulation technology and liposome technology, its antioxidant capacity increases. This may be because there is caffeic acid as the core material in the microcapsule, and caffeic acid and coffee essential oil itself have a synergistic effect. After the water phase and oil phase of the high internal phase emulsion are modified by microencapsulation and liposome technology, its antioxidant capacity can be further improved.

[0139] Although the embodiments of the present invention have been disclosed as above, they are not limited to the applications listed in the specification and implementation modes, and can be fully applicable to various fields suitable for the present invention. For those familiar with the art, for those of ordinary skill in the art, various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principle and spirit of the present invention. Therefore, without departing from the general concept defined by the claims and the scope of equivalents, the present invention is not limited to specific details.

Claims

1. A composite coffee essential oil high internal phase emulsion gel, It is characterized in that The invention comprises a water phase and an oil phase, wherein the water phase is a microcapsule and the oil phase is a liposome containing coffee essential oil; and the oil phase accounts for 72-90% of the total volume of the system.

2. The composite coffee essential oil high internal phase emulsion gel according to claim 1, It is characterized in that The microcapsules are prepared by mixing a core material, a wall material and an emulsifier in water and then subjecting them to ultrasonic treatment; wherein the mass ratio of the core material to the wall material is 1:8-1:

12.

3. The composite coffee essential oil high internal phase emulsion gel according to claim 2, It is characterized in that The core material includes any one of caffeic acid, caffeine and chlorogenic acid.

4. The composite coffee essential oil high internal phase emulsion gel according to claim 2, It is characterized in that The wall material includes any one of hydroxypropyl-β-cyclodextrin and β-cyclodextrin; the concentration of the wall material in water is 2-6%.

5. The composite coffee essential oil high internal phase emulsion gel according to claim 4, It is characterized in that The emulsifier includes any one of whey protein and zein; the concentration of the emulsifier in water is 2-6%.

6. The composite coffee essential oil high internal phase emulsion gel according to claim 2, It is characterized in that When preparing the microcapsules, the ultrasonic power is 300-500W, the ultrasonic time is 60-120min, and the ultrasonic temperature is 40-60°C.

7. The composite coffee essential oil high internal phase emulsion gel according to claim 1, It is characterized in that The liposome preparation method comprises: dissolving coffee essential oil, soybean lecithin and cholesterol in a solvent, performing rotary evaporation to obtain a film, then adding the film into a buffer solution, and finally performing ultrasonic hydration to obtain the liposome; The concentration of coffee essential oil is 0.2-0.8%, the concentration of soybean lecithin is 1-4%, and the concentration of cholesterol is 0.25-1%.

8. The composite coffee essential oil high internal phase emulsion gel according to claim 7, It is characterized in that The solvent includes any one of anhydrous ethanol, methanol and isopropanol.

9. The composite coffee essential oil high internal phase emulsion gel according to claim 7, It is characterized in that The buffer solution is a phosphate buffer solution containing polyvinyl pyrrolidone, and the volume ratio of the buffer solution to the solvent is 1:0.5-1:1.

5.

10. The composite coffee essential oil high internal phase emulsion gel according to claim 7, It is characterized in that The concentration of the phosphate buffer solution is 0.01-0.02 mol / L, wherein the concentration of polyvinyl pyrrolidone is 0.1-0.4%, and the pH of the phosphate buffer solution is 6-7.

11. The composite coffee essential oil high internal phase emulsion gel according to claim 7, It is characterized in that The temperature during the rotary evaporation is 40-60° C. and the speed is 40-70 rpm.

12. The composite coffee essential oil high internal phase emulsion gel according to claim 7, It is characterized in that The ultrasonic power during the preparation of the liposome is 300-500W, the ultrasonic time is 15-45min, and the ultrasonic temperature is 30-50°C.

13. The composite coffee essential oil high internal phase emulsion gel according to claim 1, It is characterized in that The water phase and the oil phase are mixed and fully homogenized and emulsified to obtain the composite high internal phase emulsion gel.

14. The composite coffee essential oil high internal phase emulsion gel according to claim 13, It is characterized in that The homogenization and emulsification process is carried out at a rate of 10000-20000 rpm / min, a temperature of 50-70° C., and a time of 2-6 min.

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