A whey protein-chufa starch high internal phase pickering emulsion and a preparation method thereof

Abstract

This invention discloses a whey protein isolate-tiger starch high internal phase Pickering emulsion and its preparation method, belonging to the field of green preparation technology for food functional factor delivery systems. The preparation method of the whey protein isolate-tiger starch high internal phase Pickering emulsion includes the following steps: mixing an aqueous phase containing whey protein isolate and tiger starch with tiger starch oil containing antioxidants, homogenizing the mixture, and then adjusting the pH value to obtain the whey protein isolate-tiger starch high internal phase Pickering emulsion. Conventional starch-based stabilizers typically improve the amphiphilicity of starch by introducing hydrophobic groups through chemical modification, such as using octenyl succinic anhydride (OSA) modification or organic acid esterification. This invention uses a specific ratio of tiger starch and whey protein isolate to prepare a green and efficient stabilizer under high-temperature homogenization, encapsulating tiger starch oil for homogeneous utilization.

Description

Technical Field

[0001] This invention belongs to the field of green preparation technology of food functional factor delivery system, and in particular relates to a whey protein isolate-tiger starch high internal phase Pickering emulsion and its preparation method. Background Technology

[0002] Pickering emulsions, which use solid particles to replace small-molecule surfactants to stabilize the interface, endow emulsions with excellent physical stability and resistance to digestion interference, and have become a research hotspot in the field of delivery system construction in recent years. However, existing Pickering emulsion systems still have several structural defects: the interfacial adsorption strength of single particles is limited, and particle desorption and droplet coalescence easily occur in high ionic strength environments; conventional emulsions generally have low oil loading (internal phase volume fraction <50%), resulting in insufficient absolute loading of functional factors, making it difficult to meet the needs of high-concentration delivery; and the ability to regulate emulsion properties is insufficient. In addition, traditional emulsion stabilizers (such as surfactants) often face challenges in terms of environmental friendliness and health issues during the production process.

[0003] Patent CN114903852A discloses a method for preparing and applying Pickering emulsion. It involves preparing composite nanoparticles of tiger nut protein isolate and tea polyphenols, using these composite particles as a stabilizer to construct a Pickering emulsion system under specific tiger nut oil ratios and homogeneous conditions. This significantly reduces droplet size and improves system stability, while effectively inhibiting the release of free fatty acids during gastrointestinal digestion. However, its preparation process is complex and involves excessive use of chemical reagents.

[0004] The existing technology, "Formation, stability and the application of Pickeringemulsions stabilized with OSA starch / chitosan complexes," modifies starch by esterification with octenyl succinic anhydride to give it an amphiphilic structure. This structure then forms composite particles with chitosan through electrostatic interactions, thereby creating a stable structure at the oil-water interface and improving the stability of the emulsion system. However, this technology still relies on chemical modification of starch to obtain interfacially active particles, making the preparation process relatively complex and involving the use of chemical reagents.

[0005] There is an urgent need in this field for a high internal phase Pickering emulsion that has a simple preparation process, leaves no chemical reagent residue, and has high stability. Summary of the Invention

[0006] To address the problems of complex existing starch modification processes, chemical residues, and emulsion instability, this invention provides a whey protein isolate-tiger starch high internal phase Pickering emulsion and its preparation method. This invention prepares an ultra-long-lasting and stable whey protein isolate-tiger starch high internal phase Pickering emulsion at extremely low stabilizer concentrations, fundamentally achieving the green utilization of tiger nut homologous components.

[0007] To achieve the above-mentioned objectives, the present invention adopts the following technical solution: In a first aspect, the present invention provides a method for preparing a whey protein isolate-tiger starch high internal phase Pickering emulsion, comprising the following steps: mixing an aqueous phase containing whey protein isolate and tiger starch with tiger oil containing antioxidants and homogenizing the mixture, and then adjusting the pH value to obtain the whey protein isolate-tiger starch high internal phase Pickering emulsion.

[0008] Furthermore, the preparation method of the aqueous phase includes the following steps: adding whey protein isolate and tiger nut starch to water, adding a preservative to the resulting aqueous solution, and then stirring at 500 rpm for 30 minutes at 95°C to obtain the aqueous phase.

[0009] This invention combines whey protein isolate with tiger nut starch and heats at 95°C for 30 minutes to allow the tiger nut starch and whey protein isolate to interact and form a complex structure, which significantly improves the interfacial stability of Pickering emulsion.

[0010] This invention utilizes tiger nut starch and whey protein isolate as a base, achieving in-situ synergistic effects between the two through 95℃ thermal induction treatment. This results in the formation of composite particles, which are then loaded with tiger nut oil and combined with high-shear homogenization to directly construct a Pickering emulsion system. Compared to existing technologies, this invention significantly simplifies the preparation process, yielding a whey protein isolate-tiger nut starch high internal phase Pickering emulsion. Long-term stability of the emulsion can be achieved even at a low particle concentration (3 wt.%) (zero emulsion separation index after 28 days of storage), effectively improving system stability and practical application value.

[0011] Furthermore, the mass ratio of whey protein isolate to tiger nut starch is 1:1.

[0012] Furthermore, the total mass of the whey protein isolate and tiger nut starch accounts for 3% of the mass of the aqueous phase.

[0013] This invention achieves in-situ construction of composite particles through the synergistic effect of whey protein isolate and tiger nut starch under heating conditions, obtaining good interfacial activity without chemical modification and achieving high stability of the emulsion system at low concentrations.

[0014] Furthermore, based on the total volume of the aqueous phase and the antioxidant-containing tiger nut oil being 100%, the volume percentage of the antioxidant-containing tiger nut oil is 65% to 70%.

[0015] Furthermore, based on the total volume of the aqueous phase and the antioxidant-containing tiger nuts oil being 100%, the volume percentage of the antioxidant-containing tiger nuts oil is 65%.

[0016] Furthermore, the pH value is 5.5-7.5.

[0017] Furthermore, the pH value is 5.5.

[0018] Furthermore, the antioxidants in the tiger nuts oil include astaxanthin, curcumin, and resveratrol; the mass of astaxanthin, curcumin, and resveratrol is 0.8%, 1%, and 1% of the mass of tiger nuts oil, respectively.

[0019] This invention uses natural strong antioxidants astaxanthin, curcumin and resveratrol to provide stability to Pickering emulsion, thus avoiding the introduction of chemical reagents in the selection of raw materials.

[0020] Furthermore, the homogenization process is performed by homogenizing at 20,000 rpm for 1.5 min.

[0021] Secondly, the present invention provides a whey protein isolate-tiger starch high internal phase Pickering emulsion prepared by the preparation method described above.

[0022] Compared with the prior art, the present invention has the following advantages and technical effects: Existing technologies for preparing Pickering emulsions generally employ OSA-modified starch or esterification treatment. These methods require the introduction of chemical reagents, pose residual risks, and involve complex and costly processes, hindering the construction of food-grade clean label green processing systems. This invention uses tiger nut starch and whey protein isolate composite particles as interface stabilizers to construct a whey protein isolate-tiger nut starch high internal phase Pickering emulsion (HIPE) delivery system with an internal phase volume fraction of 65%. The innovation is reflected in the following three aspects: First, the synergistic interface construction of composite wall materials: Tiger nut starch particles are rich in hydroxyl groups on their surface. Their particle size is small and their structure is regular. They exhibit a certain interfacial adsorption capacity in the Pickering emulsion system. They can form a protein-starch composite interfacial film with whey protein isolate through electrostatic adsorption and hydrophobic interaction. Compared with single protein particles, it has a higher interfacial adsorption energy and a denser steric barrier, which significantly improves the stability of the emulsion and fundamentally solves the problem of insufficient interfacial strength of single wall materials.

[0023] Second, the high internal phase ratio achieves high-density functional factor loading: Compared with traditional Pickering emulsions (internal phase ≤ 50%), the whey protein isolate-tiger starch high internal phase Pickering emulsion provided by this invention has an oil volume fraction (65%) that increases the absolute loading of functional factors per unit volume of emulsion. At the same time, the highly dense droplet stacking structure forms a three-dimensional network gel state, giving the system excellent anti-gravity stratification ability and achieving long-term physical stability without the need for additional thickeners.

[0024] Third, a green physical modification strategy: Conventional starch-based stabilizers usually introduce hydrophobic groups through chemical modification to improve the amphiphilicity of starch, such as using octenyl succinic anhydride (OSA) modification or organic acid esterification treatment. In this invention, tiger nut starch and whey protein isolate are compounded in a specific ratio and a green and efficient stabilizer is prepared under high temperature homogenization, which encapsulates tiger nut oil to achieve homologous utilization. Attached Figure Description

[0025] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0026] Figure 1 Figure a shows a comparison of the emulsion index of Pickering emulsions prepared in Examples 1, 4, and Comparative Examples 7-9 after 28 days; Figure b shows a comparison of the emulsion index of Pickering emulsions prepared in Examples 1 and Comparative Examples 3-6 after 28 days; Figure c shows a comparison of the emulsion index of Pickering emulsions prepared in Examples 1, 5-6, and Comparative Examples 10-11 after 28 days. Figure 2 Laser confocal images of whey protein isolate-tiger starch high internal phase Pickering emulsion (WPI-TNS) of Example 1, whey protein isolate Pickering emulsion (WPI) of Comparative Example 1, and tiger starch Pickering emulsion (TNS) of Comparative Example 2. Detailed Implementation

[0027] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as a limitation of the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0028] It should be understood that the terminology used in this invention is merely for describing particular embodiments and is not intended to limit the invention. Furthermore, with respect to numerical ranges in this invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Every smaller range between any stated value or intermediate value within a stated range, and any other stated value or intermediate value within said range, is also included in this invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0029] Unless otherwise stated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. While only preferred methods and materials have been described herein, any methods and materials similar or equivalent to those described herein may be used in the implementation or testing of this invention. All references to this specification are incorporated by way of citation to disclose and describe methods and / or materials associated with those references. In the event of any conflict with any incorporated reference, the content of this specification shall prevail.

[0030] Various modifications and variations can be made to the specific embodiments described in this specification without departing from the scope or spirit of the invention, as will be apparent to those skilled in the art. Other embodiments derived from this specification will also be apparent to those skilled in the art. This specification and embodiments are merely exemplary.

[0031] The terms “include,” “including,” “have,” “contain,” etc., used in this article are all open-ended terms, meaning that they include but are not limited to.

[0032] To facilitate understanding, the following technical terms will be explained.

[0033] Emulsion separation refers to the process where the dispersed phase (oil droplets) in an emulsion, due to its lower density than the continuous phase (aqueous phase), gradually floats to the top of the container under the influence of gravity, forming an enriched layer, while a clear continuous phase layer appears at the bottom.

[0034] The Creaming Index (CI) is an important indicator for evaluating the physical stability of emulsions. It is used to quantify the degree of stratification of an emulsion during the settling process, where the oil phase floats to the top or the water phase sinks due to density differences.

[0035] The calculation method of the emulsification index in the embodiments and comparative examples of the present invention is as follows: Emulsion separation index (%) = (height of water separated from emulsion / total height of emulsion) × 100%.

[0036] The room temperature in this invention refers to 25±2℃.

[0037] Example 1: A method for preparing a whey protein isolate-tiger starch high internal phase Pickering emulsion S1. Mix 2g of whey protein isolate and 2g of tiger nut starch with water to prepare an aqueous solution with a total mass concentration of 3wt.% of whey protein isolate and tiger nut starch. Add 0.2wt.% of ProClean 950 preservative to the obtained aqueous solution, stir and heat for 30min (500rpm, 95℃) to obtain a whey protein isolate-tiger nut starch wall material solution, i.e., the aqueous phase. S2. Three natural strong antioxidants, astaxanthin, curcumin and resveratrol, were dissolved in tiger nut oil at mass concentrations of 0.8%, 1% and 1%, respectively, to obtain the oil phase. S3. The aqueous phase prepared in S1 and the oil phase prepared in S2 are mixed at a volume ratio of 35:65 and homogenized at 20,000 rpm for 1.5 min. The pH is then adjusted to 5.5 with 1 mol / L hydrochloric acid to obtain a whey protein isolate-tiger starch high internal phase Pickering emulsion.

[0038] The whey protein isolate-tiger starch high internal phase Pickering emulsion prepared in Example 1 was left at room temperature for 28 days, and the emulsion separation index was 0%.

[0039] Example 2: A method for preparing a whey protein isolate-tiger starch high internal phase Pickering emulsion S1. Mix 200g of whey protein isolate and 200g of tiger nut starch with water to prepare an aqueous solution with a total mass concentration of 3wt.% of whey protein isolate and tiger nut starch. Add 0.2wt.% of ProClean 950 preservative to the obtained aqueous solution, stir and heat for 30min (500rpm, 95℃) to obtain a whey protein isolate-tiger nut starch wall material solution, i.e., the aqueous phase. S2. Three natural strong antioxidants, astaxanthin, curcumin and resveratrol, were dissolved in tiger nut oil at mass concentrations of 0.8%, 1% and 1%, respectively, to obtain the oil phase.

[0040] S3. The aqueous phase prepared in S1 and the oil phase prepared in S2 are mixed at a volume ratio of 35:65 and homogenized at 20,000 rpm for 1.5 min. The pH is then adjusted to 5.5 with 1 mol / L hydrochloric acid to obtain a whey protein isolate-tiger starch high internal phase Pickering emulsion.

[0041] The whey protein isolate-tiger starch high internal phase Pickering emulsion prepared in Example 2 was left at room temperature for 28 days, and the emulsion index was 0%.

[0042] Example 3: A method for preparing a whey protein isolate-tiger starch high internal phase Pickering emulsion S1. Mix 50g of whey protein isolate and 50g of tiger nut starch with water to prepare an aqueous solution with a total mass concentration of 3wt.% of whey protein isolate and tiger nut starch. Add 0.2wt.% of ProClean 950 preservative to the obtained aqueous solution, stir and heat for 30min (500rpm, 95℃) to obtain a whey protein isolate-tiger nut starch wall material solution, i.e., the aqueous phase. S2. Three natural strong antioxidants, astaxanthin, curcumin and resveratrol, were dissolved in tiger nut oil at mass concentrations of 0.8%, 1% and 1%, respectively, to obtain the oil phase.

[0043] S3. The aqueous phase prepared in S1 and the oil phase prepared in S2 are mixed at a volume ratio of 35:65 and homogenized at 20,000 rpm for 1.5 min. The pH is then adjusted to 5.5 with 1 mol / L hydrochloric acid to obtain a whey protein isolate-tiger starch high internal phase Pickering emulsion.

[0044] The whey protein isolate-tiger starch high internal phase Pickering emulsion prepared in Example 3 was left at room temperature for 28 days, and the emulsion separation index was 0%.

[0045] Example 4 S1-S2: Same as Example 1; S3. The aqueous phase prepared in S1 and the oil phase prepared in S2 are mixed at a volume ratio of 30:70 and homogenized at 20,000 rpm for 1.5 min. The pH is then adjusted to 5.5 with 1 mol / L hydrochloric acid to obtain a whey protein isolate-tiger starch high internal phase Pickering emulsion.

[0046] The whey protein isolate-tiger starch high internal phase Pickering emulsion prepared in Example 4 was left at room temperature for 28 days, and the emulsion index was 5.0%.

[0047] Example 5 S1-S2: Same as Example 1; S3. The aqueous phase prepared in S1 and the oil phase prepared in S2 are mixed at a volume ratio of 35:65 and homogenized at 20,000 rpm for 1.5 min. The pH is then adjusted to 7.5 with 1 mol / L NaOH solution to obtain a whey protein isolate-tiger starch high internal phase Pickering emulsion.

[0048] The whey protein isolate-tiger starch high internal phase Pickering emulsion prepared in Example 5 was left at room temperature for 28 days, and the emulsion index was 3.3%.

[0049] Example 6 S1-S2: Same as in Example 1; S3. The aqueous phase prepared in S1 and the oil phase prepared in S2 are mixed at a volume ratio of 35:65 and homogenized at 20,000 rpm for 1.5 min. The pH is then adjusted to 6.5 with 1 mol / L NaOH solution to obtain a whey protein isolate-tiger starch high internal phase Pickering emulsion.

[0050] The whey protein isolate-tiger starch high internal phase Pickering emulsion prepared in Example 6 was left at room temperature for 28 days, and the emulsion index was 5.67%.

[0051] Comparative Example 1 S1. Mix 2g of whey protein isolate with water to prepare an aqueous solution with a whey protein isolate mass concentration of 3wt.%. Add 0.2wt.% of ProClean 950 preservative to the obtained aqueous solution, stir and heat for 30min (500rpm, 95℃) to obtain a whey protein isolate wall material solution, i.e., the aqueous phase. S2. Three natural strong antioxidants, astaxanthin, curcumin and resveratrol, were dissolved in tiger nut oil at mass concentrations of 0.8%, 1% and 1%, respectively, to obtain the oil phase. S3. The aqueous phase prepared in S1 and the oil phase prepared in S2 are mixed at a volume ratio of 35:65, homogenized at 20,000 rpm for 1.5 min, and the pH is adjusted to 5.5 with 1 mol / L hydrochloric acid to obtain whey protein isolate Pickering emulsion.

[0052] After the whey protein isolate Pickering emulsion prepared in Comparative Example 1 was left at room temperature for 3 days, the emulsification index reached 23.54%.

[0053] Comparative Example 2 S1. Mix 2g of tiger nut starch with water to prepare an aqueous solution with a tiger nut starch concentration of 3wt.%. Add 0.2wt.% of ProClean 950 preservative to the obtained aqueous solution, stir and heat for 30min (500rpm, 95℃) to obtain tiger nut starch wall material solution, i.e., aqueous phase. S2. Three natural strong antioxidants, astaxanthin, curcumin and resveratrol, were dissolved in tiger nut oil at mass concentrations of 0.8%, 1% and 1%, respectively, to obtain the oil phase. S3. The aqueous phase prepared in S1 and the oil phase prepared in S2 are mixed at a volume ratio of 35:65, homogenized at 20000 rpm for 1.5 min, and the pH is adjusted to 5.5 with 1 mol / L hydrochloric acid to obtain tiger pea starch Pickering emulsion.

[0054] After the tiger nut starch Pickering emulsion prepared in Comparative Example 2 was left at room temperature for 3 days, the emulsion index reached 43.20%.

[0055] Comparative Example 3 S1. Mix 2g of whey protein isolate and 2g of tiger nut starch with water to prepare an aqueous solution with a total mass concentration of 1wt.% of whey protein isolate and tiger nut starch. Add 0.2wt.% of ProClean 950 preservative to the obtained aqueous solution, stir and heat for 30min (500rpm, 95℃) to obtain a whey protein isolate-tiger nut starch wall material solution, i.e., the aqueous phase. S2-S3: Same as Example 1.

[0056] The whey protein isolate-tiger starch high internal phase Pickering emulsion prepared in Comparative Example 3 was left at room temperature for 28 days, and the emulsion index was 23.33%.

[0057] Comparative Example 4 S1. Mix 2g of whey protein isolate and 2g of tiger nut starch with water to prepare an aqueous solution with a total mass concentration of 2wt.% of whey protein isolate and tiger nut starch. Add 0.2wt.% of ProClean 950 preservative to the obtained aqueous solution, stir and heat for 30min (500rpm, 95℃) to obtain a whey protein isolate-tiger nut starch wall material solution, i.e., the aqueous phase. S2-S3: Same as Example 1.

[0058] The whey protein isolate-tiger starch high internal phase Pickering emulsion prepared in Comparative Example 4 was left at room temperature for 28 days, and the emulsion index was 13.67%.

[0059] Comparative Example 5 S1. Mix 2g of whey protein isolate and 2g of tiger nut starch with water to prepare an aqueous solution with a total mass concentration of 4wt.% of whey protein isolate and tiger nut starch. Add 0.2wt.% of ProClean 950 preservative to the obtained aqueous solution, stir and heat for 30min (500rpm, 95℃) to obtain a whey protein isolate-tiger nut starch wall material solution, i.e., the aqueous phase. S2-S3: Same as Example 1.

[0060] The whey protein isolate-tiger starch high internal phase Pickering emulsion prepared in Comparative Example 5 was left at room temperature for 28 days, and the emulsion index was 19.33%.

[0061] Comparative Example 6 S1. Mix 2g of whey protein isolate and 2g of tiger nut starch with water to prepare an aqueous solution with a total mass concentration of 5wt.% of whey protein isolate and tiger nut starch. Add 0.2wt.% of ProClean 950 preservative to the obtained aqueous solution, stir and heat for 30min (500rpm, 95℃) to obtain a whey protein isolate-tiger nut starch wall material solution, i.e., the aqueous phase. S2-S3: Same as Example 1.

[0062] The whey protein isolate-tiger starch high internal phase Pickering emulsion prepared in Comparative Example 6 was left at room temperature for 28 days, and the emulsion index was 37.00%.

[0063] Comparative Example 7 S1-S2: Same as in Example 1; S3. The aqueous phase prepared in S1 and the oil phase prepared in S2 are mixed at a volume ratio of 50:50 and homogenized at 20,000 rpm for 1.5 min. The pH is then adjusted to 5.5 with 1 mol / L hydrochloric acid to obtain a whey protein isolate-tiger starch high internal phase Pickering emulsion.

[0064] The whey protein isolate-tiger starch high internal phase Pickering emulsion prepared in Comparative Example 7 was left at room temperature for 28 days, and the emulsion index was 15%.

[0065] Comparative Example 8 S1-S2: Same as in Example 1; S3. The aqueous phase prepared in S1 and the oil phase prepared in S2 are mixed at a volume ratio of 45:55 and homogenized at 20,000 rpm for 1.5 min. The pH is then adjusted to 5.5 with 1 mol / L hydrochloric acid to obtain a whey protein isolate-tiger starch high internal phase Pickering emulsion.

[0066] The whey protein isolate-tiger starch high internal phase Pickering emulsion prepared in Comparative Example 8 was left at room temperature for 28 days, and the emulsion index was 11.33%.

[0067] Comparative Example 9 S1-S2: Same as in Example 1; S3. The aqueous phase prepared in S1 and the oil phase prepared in S2 are mixed at a volume ratio of 40:60 and homogenized at 20,000 rpm for 1.5 min. The pH is then adjusted to 5.5 with 1 mol / L hydrochloric acid to obtain a whey protein isolate-tiger starch high internal phase Pickering emulsion.

[0068] The whey protein isolate-tiger starch high internal phase Pickering emulsion prepared in Comparative Example 9 was placed at room temperature for 28 days, and the emulsion index was 13.67%.

[0069] Comparative Example 10 S1-S2: Same as in Example 1; S3. The aqueous phase prepared in S1 and the oil phase prepared in S2 are mixed at a volume ratio of 35:65 and homogenized at 20,000 rpm for 1.5 min. The pH is then adjusted to 3.5 with 1 mol / L hydrochloric acid to obtain a whey protein isolate-tiger starch high internal phase Pickering emulsion.

[0070] The whey protein isolate-tiger starch high internal phase Pickering emulsion prepared in Comparative Example 10 was left at room temperature for 28 days, and the emulsion index was 22.67%.

[0071] Comparative Example 11 S1-S2: Same as in Example 1; S3. The aqueous phase prepared in S1 and the oil phase prepared in S2 are mixed at a volume ratio of 35:65 and homogenized at 20,000 rpm for 1.5 min. The pH is then adjusted to 4.5 with 1 mol / L hydrochloric acid to obtain a whey protein isolate-tiger starch high internal phase Pickering emulsion.

[0072] The whey protein isolate-tiger starch high internal phase Pickering emulsion prepared in Comparative Example 11 was placed at room temperature for 28 days, and the emulsion index was 14.00%.

[0073] Figure 1 Figure a shows a comparison of the emulsion index of Pickering emulsions prepared in Examples 1, 4, and Comparative Examples 7-9 after 28 days; figure b shows a comparison of the emulsion index of Pickering emulsions prepared in Examples 1 and Comparative Examples 3-6 after 28 days; and figure c shows a comparison of the emulsion index of Pickering emulsions prepared in Examples 1, 5-6, and Comparative Examples 10-11 after 28 days.

[0074] pass Figure 1 As can be seen from Figure a, the emulsion separation index generally shows a trend of first decreasing and then increasing with the increase of the oil phase volume fraction. The stability is optimal when the oil phase volume fraction is 65% and the emulsion separation index is 0%. The oil phase ratio affects the emulsion stability by influencing the complex network structure and droplet interactions. Figure 1As shown in Figure b, the emulsification index generally shows a trend of first decreasing and then increasing with the increase of the total mass concentration of whey protein isolate and tiger nut starch in the aqueous phase. The emulsification index is 0% at a total mass concentration of 3%, exhibiting the best stability. This is because at a total concentration of 3%, interfacial adsorption is saturated, the viscosity of the aqueous phase is moderate, and the aggregation and floating behavior of oil droplets are completely suppressed, resulting in no whey precipitation. Figure 1 As can be seen from c, after homogenization, as the pH of the solution increases, the emulsification index shows a trend of first decreasing, then increasing, and then decreasing again. The reason is that the surface charge of the particles affects the electrostatic repulsion and steric hindrance. When the pH of the system is 5.5, the whey protein isolate and tiger nut starch form a stable composite interface layer, and the electrostatic repulsion and steric hindrance are maximized in synergy, resulting in the best stability.

[0075] In this invention, the whey protein isolate-tiger starch high internal phase Pickering emulsion prepared in Example 1, the whey protein isolate Pickering emulsion prepared in Comparative Example 1, and the tiger starch Pickering emulsion prepared in Comparative Example 2 were stained with Nile Red and Nile Blue, respectively. Nile Red is a fat-soluble fluorescent dye, soluble only in oils, and can be used to stain and label the oil phase. Nile Blue is a water-soluble cationic dye that can bind to the hydroxyl and amino groups in proteins and starches to develop color, and is used to stain and label the stabilizer particles in the aqueous phase (i.e., the whey protein isolate and tiger starch in Example 1, the whey protein isolate in Comparative Example 1, and the tiger starch in Comparative Example 2). The staining was observed using a confocal laser scanning microscopy (CLSM). Figure 2 Laser confocal images of whey protein isolate-tiger starch high internal phase Pickering emulsion (WPI-TNS) of Example 1, whey protein isolate Pickering emulsion (WPI) of Comparative Example 1, and tiger starch Pickering emulsion (TNS) prepared in Comparative Example 2. Figure 2The oil phase was labeled with Nile Red (red channel), and the stabilizer particles were labeled with Nile Blue (blue channel). The distribution of oil droplets and interfacial particles was clearly visualized using CLSM. Results showed that when tiger nut starch was used as a stabilizer, the emulsion droplets were large and unevenly distributed, the interfacial fluorescence signal was weak, and the interfacial adsorption capacity was limited, making it difficult to form a dense, stable layer. The whey protein isolate-stabilized emulsion exhibited significantly smaller droplet sizes and more uniform distribution, but the interfacial layer was relatively soft, and stability was still limited. The whey protein isolate-tiger nut starch composite system exhibited the best structural characteristics, with the smallest and most uniform droplet size. Simultaneously, blue fluorescence formed a continuous coating layer on the oil droplet surface, presenting a typical core-shell structure. This indicates that the whey protein isolate-tiger nut starch composite particles in the whey protein isolate-tiger nut starch high internal phase Pickering emulsion prepared in this invention form a dense, stable interfacial film at the interface, significantly improving the structural stability of the emulsion.

[0076] The above are merely preferred embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for the preparation of a high internal phase pickering emulsion of whey protein isolate - cyamoposis tetragonoloba starch, characterized by, Includes the following steps: The aqueous phase containing whey protein isolate and tiger nut starch was mixed with tiger nut oil containing antioxidants and homogenized. The pH value was then adjusted to obtain the whey protein isolate-tiger nut starch high internal phase Pickering emulsion.

2. The method for preparing the whey protein isolate-tiger starch high internal phase Pickering emulsion according to claim 1, wherein the preparation method of the aqueous phase includes the following steps: Whey protein isolate and tiger nut starch were added to water, preservatives were added to the resulting aqueous solution, and the mixture was stirred at 500 rpm for 30 minutes at 95°C to obtain the aqueous phase.

3. The method for preparing whey protein isolate-tiger starch high internal phase Pickering emulsion according to claim 1, characterized in that, The mass ratio of whey protein isolate to tiger nut starch is 1:

1.

4. The method for preparing whey protein isolate-tiger starch high internal phase Pickering emulsion according to claim 1, characterized in that, The total mass of the whey protein isolate and tiger nut starch accounts for 3% of the mass of the aqueous phase.

5. The method for preparing whey protein isolate-tiger starch high internal phase Pickering emulsion according to claim 1, characterized in that, Based on the total volume of the aqueous phase and the antioxidant-containing tiger nut oil as 100%, the volume percentage of the antioxidant-containing tiger nut oil is 65% to 70%.

6. The method for preparing whey protein isolate-tiger starch high internal phase Pickering emulsion according to claim 4, characterized in that, Based on the total volume of the aqueous phase and the antioxidant-containing tiger nuts oil being 100%, the volume percentage of the antioxidant-containing tiger nuts oil is 65%.

7. The method for preparing whey protein isolate-tiger starch high internal phase Pickering emulsion according to claim 1, characterized in that, The pH value is 5.5-7.

5.

8. The method for preparing whey protein isolate-tiger starch high internal phase Pickering emulsion according to claim 6, characterized in that, The pH value is 5.

5.

9. The method for preparing whey protein isolate-tiger starch high internal phase Pickering emulsion according to claim 1, characterized in that, The antioxidants in the tiger nut oil include astaxanthin, curcumin and resveratrol; the mass of astaxanthin, curcumin and resveratrol is 0.8%, 1% and 1% of the mass of tiger nut oil, respectively.

10. A whey protein isolate-tiger starch high internal phase Pickering emulsion prepared by the preparation method according to any one of claims 1-9.

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