Preparation method of sunflower seed oil body high internal phase emulsion carrying beta-carotene

Abstract

The invention discloses a preparation method of sunflower seed oil body high internal phase emulsion carrying beta-carotene, and belongs to the technical field of lipid-soluble functional nutrient delivery system construction. The method comprises the following steps: soaking oil seeds, grinding into thick liquid, filtering, centrifuging, and collecting an upper floating layer, namely an oil body; dispersing an oil body in deionized water to obtain an oil body emulsion; heating the oil body emulsion, adding beta-carotene, and carrying out high-speed dispersion, ultrasonic treatment and homogenization treatment to obtain an oil body emulsion carrying beta-carotene; and centrifuging and collecting the upper layer to obtain the sunflower seed oil body high internal phase emulsion carrying beta-carotene. The oil body provides the oil phase and the emulsifier while carrying the beta-carotene, so that the carrying capacity of fat-soluble nutrients is remarkably improved, the problems of poor water solubility and low carrying capacity of the beta-carotene are solved, and a new method is provided for constructing a beta-carotene carrying system.

Description

Technical Field

[0001] The invention relates to the technical field of constructing a fat-soluble functional nutrient delivery system, and in particular to a method for preparing a sunflower seed oil-based high internal phase emulsion carrying beta-carotene. Background Art

[0002] β-Carotene (β-CE), a fat-soluble antioxidant, is the primary plant-derived provitamin A. Metabolized in vivo to retinoids, it participates in various life processes and is a key food functional factor. However, β-carotene's poor water solubility, low transport capacity, and low bioavailability limit its application in aqueous foods. The development of stable and effective β-carotene delivery systems is crucial for the development of β-carotene-based functional foods. Currently, emulsions are widely used for the delivery of functional nutrients.

[0003] Patent "CN116268404B A method for preparing an oil body emulsion carrying β-carotene" discloses an oil body emulsion carrying β-carotene. The method requires first preparing a soybean oil body emulsion, then adding deionized water and a neutral phosphate buffer solution to the soybean oil body emulsion as an aqueous phase; then dissolving the β-carotene in soybean oil to obtain an oil phase; then mixing the aqueous phase and the oil phase and shearing them to prepare a primary mixed solution, and then ultrasonically treating the primary mixed solution to prepare a soybean oil body-carried β-carotene emulsion. However, this patent has the following problems: β-carotene is dissolved in the oil phase, and the soybean oil body emulsion is used as the aqueous phase. After the two are mixed, the soybean oil bodies act as an emulsifier to encapsulate the oil droplets containing β-carotene to obtain an emulsion. Due to the rigid structure of the soybean oil bodies and the size of the soybean oil bodies, which can reach 500 nm or even larger, the stability of the delivery system is reduced, affecting the effect of long-term storage. In addition, the β-carotene emulsion used for soybean oil body delivery in this patent is a conventional emulsion with a low oil phase content, which further limits the amount of β-carotene carried.

[0004] High-internal-phase emulsions (HIPEs) are highly concentrated emulsions with a dispersed phase volume fraction greater than or equal to 74%. They offer potential advantages such as a high oil phase volume, high viscoelasticity, and a semisolid texture. This high oil phase volume can increase the delivery of fat-soluble nutrients, offering broad application prospects in the delivery of functional nutrients. However, the preparation of HIP emulsions requires special emulsifiers or high energy input. Exploring new, low-energy, environmentally friendly, and simple methods for preparing HIP emulsions for β-carotene delivery will promote their application in food applications and industrial development. Summary of the Invention

[0005] In response to the above-mentioned prior art, the present invention aims to provide a method for preparing a high internal phase emulsion of sunflower seed oil bodies for transporting β-carotene. To avoid the use of specialized emulsifiers, oil bodies can be used to transport β-carotene. Oil bodies are organelles within plant seed cells that store triglycerides. Oil bodies are primarily stored in oilseeds, and the oils used to produce them are widely available and inexpensive. Oil bodies have a unique structure: a triglyceride core covered by a single biofilm composed of phospholipids and oleosin. During aqueous extraction of the oil bodies, the oil bodies and storage proteins are released from the disrupted cells, with some storage proteins adsorbed to the oil body interface. The oil bodies are dispersed in water to form an oil body emulsion. Therefore, oil bodies are oil droplets encapsulated by a natural composite emulsifier (oleosin, phospholipids, and storage proteins), providing both an oil phase and a natural emulsifier for transporting functional nutrients.

[0006] Due to the special structure of oil bodies (an oil phase in the middle, surrounded by an interfacial membrane composed of phospholipids and oil body proteins), β-carotene does not easily enter the internal oil phase of the oil bodies. By regulating the structure of the oil body interfacial membrane, the inventors discovered that under conditions of heat treatment and ultrasound, the oil body interfacial membrane can be cracked, allowing β-carotene to enter the oil phase inside the oil bodies. Under the action of high-pressure homogenization, the particle size of the oil bodies carrying β-carotene is reduced, and the interfacial structure is reshaped. After centrifugation, oil bodies carrying β-carotene are formed to form a high internal phase emulsion.

[0007] To achieve the above object, the present invention adopts the following technical solutions: The first aspect of the present invention provides a method for preparing a sunflower seed oil-based high internal phase emulsion carrying β-carotene, comprising the following steps: (1) soaking sunflower seed kernels, grinding, filtering, adjusting pH, centrifuging, and collecting the floating layer to obtain sunflower seed oil bodies; (2) dispersing the sunflower seed oil bodies in deionized water to obtain a sunflower seed oil body emulsion; (3) heating the sunflower seed oil body emulsion, adding β-carotene to obtain a mixed solution, and subjecting the mixed solution to high-speed dispersion, ultrasonic treatment, and homogenization to obtain an oil body emulsion carrying β-carotene; (4) The oil body emulsion carrying β-carotene is centrifuged, and the upper layer is collected to obtain a high internal phase emulsion of sunflower seed oil bodies carrying β-carotene.

[0008] Furthermore, in step (1), the sunflower seed kernels are soaked in deionized water at 2-6° C. for 12-18 h, and then ground at a solid-liquid ratio of 1:(5-10), filtered to remove the filter residue, the filtrate pH is adjusted to 8-11, and centrifuged at 4000-10000 g to collect the floating layer to obtain sunflower seed oil bodies.

[0009] Furthermore, in step (2), the mass ratio of sunflower seed oil to deionized water is 1:(8-10).

[0010] Furthermore, in step (3), the heating temperature is 30-45° C., and the heating time is 5-45 min.

[0011] Furthermore, in step (3), the amount of β-carotene added is 0.5% of the dry weight of the sunflower seed oil body.

[0012] Furthermore, in step (3), the dispersion speed is 6000-10000 rpm / min, and the dispersion time is 1-5 min.

[0013] Furthermore, in step (3), the ultrasonic power of the ultrasonic treatment is set to 80-300 W, the ultrasonic time is 10-100 min, and the ultrasonic time interval is set to 1-5 s.

[0014] Furthermore, in step (3), the pressure of the homogenization treatment is 50-110 MPa, and the cycle is 1-5 times.

[0015] Furthermore, in step (4), the centrifugation conditions are as follows: centrifugal force is 2000-13000×g, and the centrifugation time is 20-40 min.

[0016] The second aspect of the present invention provides a sunflower seed oil high internal phase emulsion carrying β-carotene prepared by the preparation method.

[0017] Beneficial effects of the present invention: (1) The present invention prepares a sunflower seed oil body, which exhibits a paste-like semi-solid structure characteristic after being extracted by aqueous phase. This provides a new idea for the preparation of high internal phase emulsions from the perspective of maintaining the natural structure and simplifying the processing procedures of emulsified foods.

[0018] (2) In the preparation process of the sunflower seed oil body high internal phase emulsion carrying β-carotene, the present invention utilizes sunflower seed oil body to provide both the oil phase and the natural emulsifier for carrying β-carotene, which is of great significance for constructing the oil body high internal phase emulsion.

[0019] (3) The present invention constructs an oil body high internal phase emulsion through heating, high-speed dispersion, ultrasonic treatment and homogenization treatment, and the oil phase is as high as 74% or more, which significantly increases the carrying capacity of the fat-soluble nutrient β-carotene and solves the problem of poor water solubility and low carrying capacity of β-carotene.

[0020] (4) The preparation method provided by the present invention has a wide range of raw material sources, low prices, and simple operation process, which is conducive to broadening the application of oil bodies in the food industry and providing a new method for the construction of β-carotene delivery system. DETAILED DESCRIPTION

[0021] It should be noted that the following detailed descriptions are illustrative and intended to provide further explanation of the present application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which the present application belongs.

[0022] In order to enable those skilled in the art to more clearly understand the technical solution of the present application, the technical solution of the present application will be described in detail below with reference to specific embodiments.

[0023] The test materials used in the examples of the present invention are all conventional test materials in the art and can be purchased through commercial channels.

[0024] Example 1: Preparation of an oil body high internal phase emulsion carrying β-carotene (1) Sunflower seeds soaked in deionized water at 4°C for 15 h were ground with deionized water at a solid-liquid ratio of 1:8, filtered with gauze to remove the filter residue, the filtrate was adjusted to pH 9.5, and the filtrate was centrifuged at 7000 g to collect the supernatant to obtain sunflower seed oil bodies; after low-temperature drying, the water content of the sunflower seed oil body was measured to be 25.96%, and the mass of the sunflower seed oil body on a dry basis = the mass of the sunflower seed oil body * (1-the water content of the sunflower seed oil body); the fat content in the sunflower seed oil body on a dry basis obtained after drying was 89.36%.

[0025] (2) dispersing sunflower seed oil bodies in deionized water to obtain an oil body emulsion, wherein the mass ratio of the dry weight of the sunflower seed oil bodies to the deionized water is 1:9; (3) heating the oil body emulsion to 45° C. for 15 minutes. adding β-carotene to the oil body emulsion in an amount of 0.5% of the dry weight of the sunflower seed oil bodies to obtain a mixed solution; and dispersing the mixed solution at a dispersion speed of 8000 rpm / min for 3 minutes to obtain a dispersion solution; The dispersion was ultrasonically treated with an ultrasonic power of 270 W and a total ultrasonic time of 20 min (3 s on and 3 s off during ultrasonic treatment); After ultrasound, homogenization was performed at a pressure of 80 MPa, which was repeated three times to obtain an oil body emulsion carrying β-carotene.

[0026] (4) The oil body emulsion carrying β-carotene was centrifuged at a centrifugal force of 8500×g for 30 min; the upper layer was collected as the oil body high internal phase emulsion carrying β-carotene.

[0027] Example 2: Preparation of an oil body high internal phase emulsion carrying β-carotene (1) Sunflower seeds soaked in deionized water at 2°C for 12 h were ground with deionized water at a solid-liquid ratio of 1:5, filtered with gauze to remove the filter residue, and the filtrate was centrifuged at 4000 g to collect the supernatant to obtain sunflower seed oil bodies. After low-temperature drying, the water content of the sunflower seed oil bodies was measured to be 25.96%, and the mass of the sunflower seed oil body on a dry basis = the mass of the sunflower seed oil body * (1-the water content of the sunflower seed oil body). The fat content in the sunflower seed oil body on a dry basis obtained after drying was 89.13%.

[0028] (2) dispersing sunflower seed oil bodies in deionized water to obtain an oil body emulsion, wherein the mass ratio of sunflower seed oil body dry weight to deionized water is 1:8; (3) heating the oil body emulsion to 30° C. for 15 minutes. adding β-carotene to the oil body emulsion in an amount of 0.5% of the dry weight of the sunflower seed oil bodies to obtain a mixed solution; and dispersing the mixed solution at a dispersion speed of 6000 rpm / min for 5 minutes to obtain a dispersion solution; The dispersion was ultrasonically treated with an ultrasonic power of 270 W and a total ultrasonic time of 20 min (3 s on and 3 s off during ultrasonic treatment); After ultrasound, homogenization was performed at a pressure of 80 MPa, which was repeated three times to obtain an oil body emulsion carrying β-carotene.

[0029] (4) The oil body emulsion carrying β-carotene is centrifuged at a centrifugal force of 4000×g for 20 min; the upper layer is collected as the oil body high internal phase emulsion carrying β-carotene.

[0030] Example 3: Preparation of an oil body high internal phase emulsion carrying β-carotene (1) Sunflower seeds soaked in deionized water at 6°C for 18 h were ground with deionized water at a solid-liquid ratio of 1:10, filtered with gauze to remove the filter residue, and the filtrate was centrifuged at 10,000 g to collect the supernatant to obtain sunflower seed oil bodies. After low-temperature drying, the water content of the sunflower seed oil bodies was measured to be 25.19%, and the mass of the sunflower seed oil body on a dry basis = the mass of the sunflower seed oil body * (1-the water content of the sunflower seed oil body). The fat content in the sunflower seed oil body on a dry basis obtained after drying was 88.75%.

[0031] (2) dispersing sunflower seed oil bodies in deionized water to obtain an oil body emulsion, wherein the mass ratio of the dry weight of the sunflower seed oil bodies to the deionized water is 1:10; (3) heating the oil body emulsion to 35° C. for 15 minutes. adding β-carotene to the oil body emulsion in an amount of 0.5% of the dry weight of the sunflower seed oil bodies to obtain a mixed solution; and dispersing the mixed solution at a dispersion speed of 10,000 rpm / min for 1 minute to obtain a dispersion solution; The dispersion was ultrasonically treated with an ultrasonic power of 270 W and a total ultrasonic time of 20 min (3 s on and 3 s off during ultrasonic treatment); After ultrasound, homogenization was performed at a pressure of 80 MPa, which was repeated three times to obtain an oil body emulsion carrying β-carotene.

[0032] (4) The oil body emulsion carrying β-carotene was centrifuged at a centrifugal force of 13,000 × g for 40 min; the upper layer was collected as the oil body high internal phase emulsion carrying β-carotene.

[0033] Comparative Example 1 The difference between this comparative example 1 and Example 1 is that no heating or homogenization treatment is performed in step (3). The specific steps are as follows: (1) Sunflower seeds soaked in deionized water at 4°C for 15 h were ground with deionized water at a solid-liquid ratio of 1:8, filtered with gauze to remove the filter residue, the filtrate was adjusted to pH 9.5, and the filtrate was centrifuged at 7000 g to collect the supernatant to obtain sunflower seed oil bodies; after low-temperature drying, the water content of the sunflower seed oil body was measured to be 25.96%, and the mass of the sunflower seed oil body on a dry basis = the mass of the sunflower seed oil body * (1-the water content of the sunflower seed oil body); the fat content in the sunflower seed oil body on a dry basis obtained after drying was 89.36%.

[0034] (2) dispersing sunflower seed oil bodies in deionized water to obtain an oil body emulsion, wherein the mass ratio of the dry weight of the sunflower seed oil bodies to the deionized water is 1:9; (3) adding β-carotene to the oil body emulsion, wherein the amount of β-carotene added is 0.5% of the dry weight of the sunflower seed oil body, to obtain a mixed solution; and dispersing the mixed solution at a dispersion speed of 8000 rpm / min for 3 minutes to obtain a dispersion solution; The dispersion was subjected to ultrasonic treatment with an ultrasonic power of 270 W and a total ultrasonic time of 20 min (during ultrasonic treatment, the working period was 3 s and the interval was 3 s); and an oil body emulsion carrying β-carotene was obtained.

[0035] (4) The oil body emulsion carrying β-carotene was centrifuged at a centrifugal force of 8500×g for 30 min; the upper layer was collected as the oil body high internal phase emulsion carrying β-carotene.

[0036] Comparative Example 2 The difference between this comparative example 2 and Example 1 is that no heating treatment is performed in step (3). The specific steps are as follows: (1) Sunflower seeds soaked in deionized water at 4°C for 15 h were ground with deionized water at a solid-liquid ratio of 1:8, filtered with gauze to remove the filter residue, the filtrate was adjusted to pH 9.5, and the filtrate was centrifuged at 7000 g to collect the supernatant to obtain sunflower seed oil bodies; after low-temperature drying, the water content of the sunflower seed oil body was measured to be 25.96%, and the mass of the sunflower seed oil body on a dry basis = the mass of the sunflower seed oil body * (1-the water content of the sunflower seed oil body); the fat content in the sunflower seed oil body on a dry basis obtained after drying was 89.36%.

[0037] (2) dispersing sunflower seed oil bodies in deionized water to obtain an oil body emulsion, wherein the mass ratio of the dry weight of the sunflower seed oil bodies to the deionized water is 1:9; (3) adding β-carotene to the oil body emulsion, wherein the amount of β-carotene added is 0.5% of the dry weight of the sunflower seed oil body, to obtain a mixed solution; and dispersing the mixed solution at a dispersion speed of 8000 rpm / min for 3 minutes to obtain a dispersion solution; The dispersion was ultrasonically treated with an ultrasonic power of 270 W and a total ultrasonic time of 20 min (3 s on and 3 s off during ultrasonic treatment); After ultrasonic treatment, homogenization was performed at a pressure of 80 MPa for 3 cycles to obtain an oil body emulsion carrying β-carotene. (4) The oil body emulsion carrying β-carotene was centrifuged at a centrifugal force of 8500×g for 30 min; the upper layer was collected as the oil body high internal phase emulsion carrying β-carotene.

[0038] Comparative Example 3 The difference between this comparative example 3 and Example 1 is that no homogenization treatment is performed in step (3). The specific steps are as follows: (1) Sunflower seeds soaked in deionized water at 4°C for 15 h were ground with deionized water at a solid-liquid ratio of 1:8, filtered with gauze to remove the filter residue, the filtrate was adjusted to pH 9.5, and the filtrate was centrifuged at 7000 g to collect the supernatant to obtain sunflower seed oil bodies; after low-temperature drying, the water content of the sunflower seed oil body was measured to be 25.96%, and the mass of the sunflower seed oil body on a dry basis = the mass of the sunflower seed oil body * (1-the water content of the sunflower seed oil body); the fat content in the sunflower seed oil body on a dry basis obtained after drying was 89.36%.

[0039] (2) dispersing sunflower seed oil bodies in deionized water to obtain an oil body emulsion, wherein the mass ratio of the dry weight of the sunflower seed oil bodies to the deionized water is 1:9; (3) heating the oil body emulsion to 38° C. for 15 minutes. adding β-carotene to the oil body emulsion in an amount of 0.5% of the dry weight of the sunflower seed oil bodies to obtain a mixed solution; and dispersing the mixed solution at a dispersion speed of 8000 rpm / min for 3 minutes to obtain a dispersion solution; The dispersion was subjected to ultrasonic treatment with an ultrasonic power of 270 W and a total ultrasonic time of 20 min (during ultrasonic treatment, the working period was 3 s and the interval was 3 s); and an oil body emulsion carrying β-carotene was obtained.

[0040] (4) The oil body emulsion carrying β-carotene was centrifuged at a centrifugal force of 8500×g for 30 min; the upper layer was collected as the oil body high internal phase emulsion carrying β-carotene.

[0041] Test example: The samples of Examples 1 to 3 and Comparative Examples 1 to 3 were tested for β-carotene embedding efficiency, particle size of the oil body emulsion carrying β-carotene, and β-carotene retention rate. The test methods are as follows: (1) Determination of β-carotene embedding efficiency Preparation of the β-CE standard curve: Weigh 5.0 mg of the β-CE standard sample, dissolve it in n-hexane, and dilute to a 50 mL volumetric flask. Take 25 mL of this solution and dilute it again to a 50 mL volumetric flask. Then, take 0, 1, 2, 3, 4, and 5 mL of this solution and dilute to a 10 mL volumetric flask to obtain a concentration gradient of 0, 5, 10, 15, 20, and 25 μg / mL standard solutions. Use the n-hexane solution as a blank control. Measure the absorbance at 450 nm and prepare a standard curve to be used as the standard concentration curve for measuring the embedding efficiency.

[0042] Determination of β-CE embedding efficiency of the sample to be tested: Take 1 mL of the sample in a centrifuge tube, add 4 mL of n-hexane, vortex and oscillate for 30 seconds, centrifuge in a refrigerated centrifuge for 5 minutes, 8000 r / min, room temperature, collect the supernatant, use n-hexane as a control, and measure the absorbance A1 at 450 nm. Take the lower layer of liposomes and add 4 mL of anhydrous ethanol. After thorough oscillation and mixing, add 5 mL of n-hexane, centrifuge at 8000 r / min for 5 minutes, collect the supernatant, use n-hexane as a blank control, and measure the absorbance A2 at 450 nm. Substitute the absorbances A1 and A2 into the standard curve to calculate the free β-CE content and the embedded β-CE content, and the embedding efficiency E M The calculation formula (%) is as follows: E M (%)=C0 / (C0+ C1)*100% Where: C0 is the mass concentration of free β-CE, unit is mg / mL; C1 is the mass concentration of embedded β-CE, unit is mg / mL.

[0043] (2) Determination of particle size: Particle size determination Measure the average particle size (D4,3) of the sample at 25°C: Take 10 μL of the sample to be tested and add PBS to dilute it 1000 times, place it in a test tube and mix it evenly. Stop adding the sample when the shielding rate is 15-20%. Repeat the sample measurement 3 times.

[0044] (3) Determination of β-carotene retention rate The prepared emulsion was placed in a set environment (4°C) and stored away from light. A small amount of emulsion was taken out regularly for measurement, and the changes in β-CE retention rate were recorded and analyzed. The retention rate was calculated as follows: Retention rate (%) = C / C 0 *100% Where: C is the β-CE content after storage for a certain period of time, in mg / mL; C 0 is the initial content of β-CE, unit: mg / mL.

[0045] (4) Determination of carrying capacity The carrying capacity is the mass of β-carotene carried per 100g of sunflower oil high internal phase emulsion.

[0046] Carrying capacity = oil phase volume fraction * embedding rate * amount of added β-carotene The test results of each project are shown in Table 1 below: Table 1 Test results The above description is merely a preferred embodiment of the present application and is not intended to limit the present application. Various modifications and variations are possible for those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present application shall be included within the scope of protection of the present application.

Claims

1. A method for preparing a sunflower seed oil-based high internal phase emulsion carrying β-carotene, characterized in that: The following steps are involved: (1) soaking sunflower seed kernels, grinding, filtering, adjusting pH, centrifuging, and collecting the floating layer to obtain sunflower seed oil bodies; (2) dispersing the sunflower seed oil bodies in deionized water to obtain a sunflower seed oil body emulsion; (3) heating the sunflower seed oil body emulsion, adding β-carotene to obtain a mixed solution, and subjecting the mixed solution to high-speed dispersion, ultrasonic treatment, and homogenization to obtain an oil body emulsion carrying β-carotene; (4) The oil body emulsion carrying β-carotene is centrifuged, and the upper layer is collected to obtain a high internal phase emulsion of sunflower seed oil bodies carrying β-carotene.

2. The preparation method according to claim 1, characterized in that In step (1), the sunflower seed kernels are soaked in deionized water at 2-6° C. for 12-18 h, and then ground at a solid-liquid ratio of 1:(5-10), filtered to remove the filter residue, the filtrate pH is adjusted to 8-11, and centrifuged at 4000-10000 g to collect the floating layer to obtain sunflower seed oil bodies.

3. The preparation method according to claim 1, characterized in that In step (2), the mass ratio of sunflower seed oil to deionized water is 1:(8-10).

4. The preparation method according to claim 1, characterized in that In step (3), the heating temperature is 30-45° C. and the heating time is 5-45 min.

5. The preparation method according to claim 1, characterized in that In step (3), the amount of β-carotene added is 0.5% of the dry weight of the sunflower seed oil body.

6. The preparation method according to claim 1, characterized in that In step (3), the dispersion speed is 6000-10000 rpm / min, and the dispersion time is 1-5 min.

7. The preparation method according to claim 1, characterized in that In step (3), the ultrasonic power of the ultrasonic treatment is set to 80-300 W, the ultrasonic time is 10-100 min, and the ultrasonic time interval is set to 1-5 s.

8. The preparation method according to claim 1, characterized in that In step (3), the homogenization pressure is 50-110 MPa, and the cycle is 1-5 times.

9. The preparation method according to claim 1, characterized in that In step (4), the centrifugation conditions are: centrifugal force of 2000-13000×g, and centrifugation time of 20-40 min.

10. The sunflower seed oil-based high internal phase emulsion carrying β-carotene prepared by the method according to any one of claims 1 to 9.

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