Preparation method and application of waxy corn starch-based astaxanthin Pickering emulsion

Abstract

The invention relates to the technical field of food processing, and particularly discloses a waxy corn starch-based astaxanthin Pickering emulsion preparation method which comprises the following steps: (1) adding waxy corn starch into octenyl succinic anhydride for esterification to obtain octenyl succinic acid waxy corn starch, putting astaxanthin into soybean oil, and fully stirring and uniformly mixing to obtain an oil phase; (2) mixing the oil phase and the water phase according to a ratio of 3: 1, and dispersing at a high speed; (3) respectively adjusting the pH value and the temperature, and preparing a high internal phase Pickering emulsion according to the step (2) to obtain different samples; the application of the high-internal-phase Pickering emulsion is that the high-internal-phase Pickering emulsion is applied to 3D printing. Through the enzymolysis process, effective compounding of the waxy corn starch and the soybean protein isolate is promoted, a more stable network structure is formed, the process is simple, green and environment-friendly, the cost is low, and the shear resistance and long-term stability of the emulsion are effectively improved.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of food processing, in particular to a preparation method and application of a wax corn starch-based astaxanthin Pickering emulsion. BACKGROUND

[0002] High internal phase Pickering emulsion has been widely used in fat substitutes, embedding of bioactive substances (such as astaxanthin), 3D printing and other fields due to its unique structural advantages, showing great potential in modern food industry. However, there are few high internal phase Pickering emulsions with two or more application potentials at present. The reason is that high internal phase Pickering requires high environmental factors, and changes in pH, salt ion concentration and other factors can easily cause damage to the interface layer and emulsion instability; the rheological properties of the emulsion are poor, and the mechanical strength is low; in addition, the number of edible or biocompatible materials that can be used for 3D printing is limited.

[0003] The amylose content of ordinary corn starch is about 22% to 27%, and the amylose content of high amylose corn starch can reach 50% to 56%. The linear structure of amylose makes it prone to aging and difficult to dissolve in water. The amylose content of waxy corn starch is usually less than 5%, or even negligible, which makes its solubility, transparency and viscosity significantly higher than that of ordinary corn starch. By enzymatic modification of octenyl succinic anhydride waxy corn starch, the complexation with soybean protein isolate is promoted, a tighter interface layer is formed, and the extreme environmental adaptability of the emulsion is improved; the rheological properties are improved, and the emulsion has excellent creep recovery ability, which is more suitable for application in 3D printing; at the same time, the green raw materials and process are used for preparation, which meets the requirements of consumers and laws, and the high internal phase Pickering emulsion prepared by the method also has important significance for embedding and delivering astaxanthin.

[0004] In the prior art, CN114907578A discloses a preparation method of nano-lignin-cellulose nanofiber synergistically stabilized high internal phase Pickering gel. Both nano-lignin and cellulose nanofiber are more stable at high pH, and the pH stability and salt ion stability are not disclosed. Moreover, the viscosity of the emulsion gel synergistically stabilized by the two is low, which is not suitable for application in 3D printing.

[0005] CN113892632A discloses a method for preparing Pickering emulsion by using modified macroprotein micelles. The process uses heating, ultrasonic and pH shift combined technology to modify the macroprotein, which is complex. Although the process has good stability, the rheological properties are poor and the support is insufficient.

[0006] CN117796450A discloses a preparation method for 3D printing of tea residue protein-based Pickering emulsion gel, which solves the problem of high fat content, but the amount of tea residue protein and food colloid is large, the cost is high, and the extreme environmental stability and the ability to embed and carry bioactive substances are not disclosed.

[0007] In summary, the prior art has certain research on high internal phase Pickering emulsion for single application, but there are still problems such as poor rheological properties, low adaptability to extreme environment, high cost, and application limitations. Therefore, it is necessary to provide a preparation method of wax corn starch-based astaxanthin Pickering emulsion to overcome the existing problems. SUMMARY

[0008] Based on the problems or deficiencies in the prior art, the purpose of the present application is to provide a preparation method of wax corn starch-based high internal phase Pickering emulsion for embedding astaxanthin, so as to obtain a natural composite stable high internal phase Pickering emulsion, thereby embedding the bioactive substance astaxanthin, improving its physicochemical stability, preventing its degradation under the influence of environmental factors, and enhancing its retention rate during storage and processing, while evaluating the feasibility and structural stability of high internal phase Pickering emulsion as food field 3D printing ink.

[0009] In order to achieve the above-mentioned purpose, the present application provides a preparation method of wax corn starch-based astaxanthin Pickering emulsion, comprising the following steps:

[0010] (1) esterification of wax corn starch with octenyl succinic anhydride to obtain octenyl succinic anhydride wax corn starch, which is enzymatically hydrolyzed with high-temperature resistant alpha-amylase to obtain enzymatically hydrolyzed octenyl succinic anhydride wax corn starch, which is dissolved with soybean protein isolate, respectively, and the complex solution is obtained after compounding, and the astaxanthin is mixed uniformly in soybean oil by stirring to obtain an oil phase;

[0011] (2) mixing the oil phase and the water phase in a ratio of 3:1, high-speed dispersion, to obtain a high internal phase Pickering emulsion embedding astaxanthin, and the emulsion is treated at different temperatures and different ultraviolet irradiation times to obtain high internal phase Pickering emulsions with different temperature treatments and different ultraviolet irradiation times;

[0012] (3) adjusting pH, salt ion concentration, and temperature, respectively, and preparing high internal phase Pickering emulsion according to step (2) to obtain samples under different pH, salt ion, and temperature conditions.

[0013] Preferably, the starch in step (1) can be selected from wax corn starch, ordinary corn starch, and potato starch due to process compatibility.

[0014] Furthermore, waxy corn starch is preferred.

[0015] Preferably, the esterification reaction in step (1) involves a waxy corn starch milk concentration of 35% w / w on a dry basis, a reaction time of 3–5 h, and a reaction pH of 8.0–8.5.

[0016] Preferably, the enzymatic hydrolysis temperature in step (1) is 96°C, the enzyme dosage is 10-100 U / g dry starch, and the enzymatic hydrolysis time is 5-60 min.

[0017] Preferably, in step (1), the concentration of the enzymatically hydrolyzed octenyl succinic acid waxy corn starch and soy protein isolate is 0.5% to 5%, the ratio is 1:5 to 5:1, and the amount of astaxanthin added is 0.005% to 0.1% w / v.

[0018] Preferably, the high-speed dispersion conditions in step (2) are: 10000~15000rad / min dispersion for 0.5~3min, temperature 4℃~70℃, treatment for 10~30min, and ultraviolet irradiation time for 0~30h.

[0019] Preferably, in step (3), the pH is 2-11, the salt ion concentration is 0-1000 mmol, and the temperature is 4-100℃.

[0020] This invention also provides the application of an enzymatically hydrolyzed octenyl succinic acid waxy corn starch and soy protein isolate complex containing astaxanthin for 3D printing.

[0021] Through the above technical solution: In the initial invention process, the inventors planned to use octenyl succinic acid waxy corn starch and soy protein isolate to make a compound. However, they found that the particle size of the compound prepared by the two was large. Preliminary experiments showed that the emulsion prepared by this compound as an emulsifier had poor stability and physicochemical properties, and was not suitable for subsequent embedding and 3D printing applications. After multiple experiments, it was found that the particle size of the compound prepared by enzymatic hydrolysis of octenyl succinic acid waxy corn starch and then compounding it with soy protein isolate was significantly reduced. By improving the enzymatic hydrolysis time, the optimal compound was finally obtained, which greatly improved the above problems.

[0022] In summary, this application has the following beneficial effects:

[0023] 1. This application promotes the effective compounding of waxy corn starch and soy protein isolate through enzymatic hydrolysis, forming a more stable network structure. The process is simple, environmentally friendly, and low-cost, effectively improving the shear resistance and long-term stability of the emulsion.

[0024] 2. The high internal phase Pickering emulsion in this application has excellent adaptability to extreme environments and can effectively reduce the damage of environmental factors to astaxanthin.

[0025] 3. The high internal phase Pickering emulsion of this application still retains astaxanthin at 89.87%, 80.43%, and 62.34% respectively after 35 days of storage, treatment at 70℃, and 27 hours of UV irradiation, demonstrating excellent retention effects.

[0026] 4. The high internal phase Pickering emulsion of the present invention can be used as a fat substitute to prepare low-fat foods, and can also be used for the encapsulation and delivery of bioactive substances such as astaxanthin. Furthermore, it can be used as food 3D printing ink, integrating multiple functions into one. Attached Figure Description

[0027] Figure 1 This is a particle size diagram of the emulsion under the influence of different environmental factors in the embodiments of the present invention;

[0028] Figure 2 This is a particle size distribution of the astaxanthin-encapsulated emulsion in an embodiment of the present invention.

[0029] Figure 3 Examples of the present invention include (a) the astaxanthin standard curve and (b) the astaxanthin retention rate during storage.

[0030] Figure 4 This is a graph showing the effect of temperature on the retention rate of astaxanthin emulsion in an embodiment of the present invention.

[0031] Figure 5 This is a graph showing the effect of ultraviolet irradiation on astaxanthin retention rate in an embodiment of the present invention;

[0032] Figure 6 This is a diagram showing the release of free fatty acids and the bioavailability of the astaxanthin-encapsulated emulsion in this embodiment of the invention (a).

[0033] Figure 7 These are 3D printing images of emulsions under the influence of different environmental factors in the embodiments of the invention;

[0034] Figure 8 The image shown is a 3D printing image of astaxanthin emulsion in an embodiment of the present invention.

[0035] Figure 9 This is a flowchart of a waxy corn starch-based Pickering emulsion and its preparation method according to the present invention. Detailed Implementation

[0036] To better understand the present invention, the following embodiments are provided for further explanation and illustration, but the implementation of the present invention is not limited thereto. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains. To enable those skilled in the art to more clearly understand the technical solutions of this application, the technical solutions of this application will be described in detail below with reference to specific embodiments. If specific experimental conditions are not specified in the embodiments, conventional conditions are generally followed; reagents, materials, etc., used in the following embodiments, unless otherwise specified, can be obtained commercially.

[0037] Example 1:

[0038] A waxy corn starch-based Pickering emulsion and its preparation method include the following steps:

[0039] (1) Preparation of octenyl succinic acid waxy corn starch: Waxy corn starch was prepared into 35% (w / w, dry basis) starch milk, stirred in a water bath at 35℃, alkalized for 20 min, octenyl succinic acid was added for esterification, and reacted at pH 8.0 for 3 h. The pH was adjusted to 6.5 to terminate the reaction. The product was washed, centrifuged, dried, ground and sieved to obtain octenyl succinic acid starch.

[0040] (2) Preparation of enzymatically hydrolyzed octenyl succinic acid waxy corn starch: The octenyl succinic acid waxy corn starch obtained in step (1) was dissolved in phosphate buffer, gelatinized in a boiling water bath for 30 min, cooled to 96℃, and then hydrolyzed with 40 U / g (dry starch basis) of thermoresistant α-amylase. The pH was then adjusted to 3.0 to inactivate the enzyme, and then adjusted to neutral. The mixture was spray-dried to obtain enzymatically hydrolyzed octenyl succinic acid waxy corn starch.

[0041] (3) Preparation of aqueous phase: Enzymatically hydrolyzed octenyl succinic acid waxy corn starch and soy protein isolate were prepared into solutions respectively, and mixed by constant dropwise addition at a ratio of 1:1 (v / v). The mixed solution was placed in a magnetic stirrer and stirred at 800 rad / min for 1 h to obtain a complex solution.

[0042] (5) Preparation of high internal phase Pickering emulsion stabilized by enzymatic hydrolysis of octenyl succinic acid waxy corn starch-soy protein isolate complex as emulsifier: The oil phase and water phase were mixed in a ratio of 3:1 and dispersed at high speed of 12000 rad / min for 2 min to obtain high internal phase Pickering emulsion.

[0043] (6) Application of high internal phase Pickering emulsion in 3D printing: The high internal phase Pickering emulsion is loaded into the barrel of the 3D printer, the printing temperature is 25℃, the nozzle tip diameter is 0.40mm, the extrusion speed is 15mm / s, and 3D printing is performed according to the preset model to print a 1×1×1cm cube, a Superman icon and a maple leaf respectively.

[0044] Example 2:

[0045] This embodiment has the same emulsion preparation steps as Example 1, the difference being that the aqueous phase preparation does not include enzymatic hydrolysis of octenyl succinic acid waxy corn starch, but only uses soy protein isolate.

[0046] Example 3:

[0047] The emulsion preparation steps in this embodiment are the same as those in Example 1, except for the preparation of the oil phase: 0.01% (w / v) astaxanthin is placed in soybean oil and magnetically stirred at 600 rad / min for 1 h until it is mixed evenly to obtain the oil phase.

[0048] Example 4:

[0049] The emulsion preparation steps in this embodiment are the same as those in Example 2, except for the preparation of the oil phase: 0.01% (w / v) astaxanthin is placed in soybean oil and magnetically stirred at 600 rad / min for 1 h until it is mixed evenly to obtain the oil phase.

[0050] Comparative Example 1:

[0051] The preparation steps are the same as in Examples 1 and 2, except that the pH is adjusted to 3.0, 4.5, 6.0, 7.5 and 9.0 respectively to obtain the aqueous phase.

[0052] Comparative Example 2:

[0053] The preparation steps are the same as in Examples 1 and 2, except that the salt ion concentrations are adjusted to 0 mmol, 100 mmol, 300 mmol, 500 mmol, and 700 mmol respectively during the preparation of the aqueous phase to obtain the aqueous phase.

[0054] Comparative Example 3:

[0055] The preparation steps are the same as in Examples 1 and 2, except that the emulsion is treated at 4℃, 25℃, 37℃, 60℃ and 70℃ for half an hour after preparation.

[0056] Comparative Example 4:

[0057] The preparation steps are the same as in Examples 3 and 4, except that the obtained high internal phase Pickering emulsion containing astaxanthin is treated at 4°C, 25°C, 37°C, 60°C and 70°C for half an hour to obtain astaxanthin high internal phase Pickering emulsions under different temperature treatment conditions.

[0058] Comparative Example 5:

[0059] The preparation steps are the same as in Examples 3 and 4, except that the obtained high internal phase Pickering emulsion containing astaxanthin is treated under conditions of 0 to 30 h to obtain astaxanthin high internal phase Pickering emulsions under different ultraviolet irradiation time treatment conditions.

[0060] Experimental Example 1:

[0061] The particle size of the enzymatically hydrolyzed starch prepared in this example was determined using a laser particle size analyzer.

[0062] The particle size of the samples was determined using a laser particle size analyzer. A 1% sample solution was prepared, with deionized water as the dispersion medium and the temperature set at 25°C. The solution was equilibrated for 2 minutes before testing. At least three replicates were performed for each sample.

[0063] In Example 1, the particle size of the enzymatically hydrolyzed octenyl succinic acid waxy corn starch obtained after different times of enzymatic hydrolysis with heat-resistant α-amylase is shown in Table 1. With the extension of enzymatic hydrolysis time, the particle size of the enzymatically hydrolyzed octenyl succinic acid waxy corn starch showed a trend of first decreasing and then increasing. In order to better combine it with soy protein isolate, obtain a smaller composite particle size, and further improve the stability of the emulsion, enzymatic hydrolysis for 10 min was selected for subsequent experiments.

[0064] Table 1. Particle size of enzymatically hydrolyzed octenyl succinic acid waxy corn starch at different hydrolysis times.

[0065]

[0066]

[0067] Note: Different lowercase letters in each column indicate significant differences between different samples (p<0.05).

[0068] Experimental Example 2:

[0069] The particle size of the high internal phase Pickering emulsion prepared in this example was determined using an HL3100 laser particle size analyzer.

[0070] The particle size of the emulsion was determined using an HL3100 laser particle size analyzer, with the following settings: refractive index: 1.45, dispersant refractive index: 1.33, and density: 0.945 kg / m³. 3Add the sample to the sample cell, and stop adding the sample when the shading rate reaches 15%–20%. Then begin the particle size and particle size distribution determination and analysis. The emulsion particle size is expressed as the area average particle size (D). 3,2 ) and volume average particle size (D 4,3 This indicates that each sample was measured in three parallel samples, and the average value was taken.

[0071] From the appendix Figure 1 It can be seen that, in Comparative Example 1 at pH 3.0, the stable high internal phase Pickering emulsion D in Example 2... 3,2 and D 4,3 The thicknesses are 10.71 μm and 24.41 μm, respectively, while the stable high internal phase Pickering emulsion D of Example 1... 3,2 and D 4,3 The particle sizes were 7.11 μm and 15.55 μm, respectively. At the protein isoelectric point, the particle sizes of both Examples 1 and 2 increased significantly, but Example 1 showed better stability than Example 2. The particle size decreased with increasing pH. At any pH, the particle size of Example 1 was the same as that of Example 2, exhibiting better stability.

[0072] In Comparative Example 2, the droplet size increased slightly after treatment with 100 mmol salt ions. With further increases in salt ion concentration, the droplet size in Example 2 initially decreased and then increased. In contrast, in Example 1, the particle size decreased slightly with increasing salt ion concentration, reaching only 6.88 μm after treatment with 700 mmol salt ions, significantly smaller than the 13.36 μm in Example 2. Overall, the salt ion stability of Example 1 was superior to that of Example 2.

[0073] In Comparative Example 3, both Examples 1 and 2 showed an increase in particle size with increasing temperature. However, the increase in particle size in Example 1 at high temperature was significantly smaller than that in Example 2, indicating that the addition of enzymatically hydrolyzed octenyl succinic acid waxy corn starch effectively improved the thermal stability of soy protein isolate.

[0074] Depend on Figure 2 It can be seen that there is no significant difference in droplet size between the emulsion containing astaxanthin and the emulsion without astaxanthin, and the particle size also does not show significant changes, indicating that astaxanthin has little effect on emulsion stability. Compared with Example 4, the droplets in Example 3 are significantly smaller. After 35 days of storage, the droplets in Example 3... 3,2 Increased to 8.20 μm, D in Experimental Example 4 3,2 The particle size increased to 12.48 μm. Example 3, after 35 days of storage, remained smaller than the particle size on the day of preparation of Example 4, demonstrating excellent stability.

[0075] Experimental Example 3:

[0076] The retention rate of the astaxanthin-encapsulated high internal phase Pickering emulsion prepared in this embodiment was determined:

[0077] Retention rates were determined at 0, 1, 3, 7, 14, 21, 28, and 35 days. 0.2 mL of a high-internal-phase Pickering emulsion containing astaxanthin was added to 8 mL of acetone solution. After vortexing for 30 s, the mixture was centrifuged at 8000 g for 10 min. The supernatant was collected, and the absorbance of the sample was measured at 475 nm using a UV spectrophotometer. The formula for calculating the astaxanthin retention rate is as follows:

[0078] Astaxanthin retention rate (%) = C t / C0×100;

[0079] In the formula, C0 and C t The values ​​represent the concentrations of astaxanthin in the high internal phase Pickering emulsion after 0 days of storage and t days of storage, respectively.

[0080] Depend on Figure 3 It was found that after 35 days of storage, the astaxanthin retention rates, from highest to lowest, were: emulsion of Example 3 (89.87%) > emulsion of Example 4 (73.58%) > oil sample (37.78%). Throughout the storage period, the retention rates of all samples showed a decreasing trend, with the oil sample showing a significant decrease in retention rate over time, indicating that astaxanthin was not effectively protected and underwent severe degradation. In contrast, the emulsion system provided better protection for astaxanthin; only 10.13% of the astaxanthin in the emulsion of Example 3 leaked or degraded, indicating that its emulsion interface film effectively prevented astaxanthin leakage.

[0081] Experimental Example 4:

[0082] The thermal stability of the astaxanthin-encapsulated high internal phase Pickering emulsion prepared in Comparative Example 4 was determined:

[0083] The retention rate of the emulsion was measured after being treated in a water bath at 4℃, 25℃, 37℃, 60℃ and 70℃ for 30 min.

[0084] Depend on Figure 4 It can be seen that the emulsion of Example 4 showed no significant change in appearance under low-temperature treatment, but its color lightened slightly at 70°C, consistent with the change in retention rate. The retention rate was high at 4°C and 25°C, decreasing to 97.63% at 37°C. With further increases in temperature, the retention rate decreased to 75.89% and 69.43% at 60°C and 70°C, respectively. In contrast, the astaxanthin emulsion of Example 3 showed no significant change in appearance after heating, with almost the same retention rate at 4°C and 25°C, a slight decrease at 37°C, a retention rate of 82.46% at 60°C, and 80.43% at 70°C, significantly better than the emulsion of Example 4 in terms of astaxanthin protection.

[0085] Experimental Example 5:

[0086] The UV radiation stability of the astaxanthin-encapsulated high-internal-phase Pickering emulsion prepared in Comparative Example 5 was determined:

[0087] The retention rate of the emulsion was measured after irradiation with a UV lamp for 0h, 1h, 3h, 5h, 7h, 9h, 11h, 22h and 27h respectively.

[0088] Depend on Figure 5 It can be seen that the emulsion gradually faded with prolonged light exposure. After 22 hours of UV irradiation, the astaxanthin emulsion of Example 4 turned significantly white, and the astaxanthin retention rate dropped to 50.67%. In contrast, the astaxanthin emulsion of Example 3 showed a slower change in appearance, with a retention rate of 68.45% after 22 hours of treatment, significantly higher than that of Example 4. After 27 hours of light treatment, the retention rate of the astaxanthin emulsion of Example 4 dropped to 45.28%, while the retention rate of the emulsion of Example 3 was 62.34%. This result indicates that the emulsion of Example 3 can more effectively reduce the effect of light on astaxanthin.

[0089] Experimental Example 6:

[0090] Lipid digestion of the astaxanthin-encapsulated high internal phase Pickering emulsion prepared in this example was determined:

[0091] 10 mL of the emulsion sample was mixed with an equal volume of artificial saliva and reacted in a 37°C water bath shaker for 2 min. The sample after oral digestion was mixed with gastric digestion fluid at a 1:1 ratio, the pH was adjusted to 2.0, and digested in a 37°C water bath shaker for 2 h. The sample after gastric digestion was mixed with artificial intestinal fluid at a 1:1 ratio, the pH was adjusted to 7.0 with sodium hydroxide (0.5 mol / L), and digested in a 37°C water bath shaker for 2 h. Sodium hydroxide was continuously added to maintain the pH of the digestion fluid at 7.0, and the volume and addition time of sodium hydroxide were recorded. The amount of free fatty acids released was calculated using the following formula:

[0092] Free fatty acid release (%) = (V NaOH ×M NaOH ×M oil ) / (W oiI ×2)×100;

[0093] In the formula V NaOH and M NaOH These are the volume and molar concentration of the sodium hydroxide solution, M and M, respectively. oil and W oil These are the average molecular weight (880 g / mol) and mass of soybean oil in the small intestine stage, respectively.

[0094] Samples digested via the mouth, stomach, and intestines were collected and ultracentrifuged for 30 min (4℃, 13000g). The intermediate micelle phase was collected, and astaxanthin was extracted from the micelle phase with acetone solution. The mixture was vortexed for 30 s to ensure thorough mixing, and then centrifuged at 10000g for 10 min. The supernatant was collected, and the extraction was repeated three times. The absorbance of the supernatant at 475 nm was measured using a UV spectrophotometer. Bioaccessibility was calculated using the following formula:

[0095] Biological accessibility (%) = mass of astaxanthin in micelles / mass of astaxanthin in digestive fluid × 100;

[0096] Depend on Figure 6 It can be seen that both the emulsions of Example 4 and Example 3 exhibited a relatively rapid trend of free fatty acid release in the first 20 minutes. Compared to Example 4, Example 3 showed a higher level of free fatty acid release in the first 20 minutes. After 120 minutes of digestion, the free fatty acid release rates of Example 4 and Example 3 were 57.16% and 70.94%, respectively, indicating that Example 3 had a higher degree of fat hydrolysis. The bioavailability of Example 3 was 37.01%, significantly higher than that of Example 4 (31.15%). This may be because a high level of free fatty acid release generally facilitates the dissolution and absorption of astaxanthin, promoting its dissolution and improving its bioavailability.

[0097] Experimental Example 7:

[0098] The 3D printing effect of the high internal phase Pickering emulsion prepared in this embodiment was measured:

[0099] Printing experiments were conducted using a 3D printer. The emulsion was filled into the printer's syringe before printing. The nozzle tip diameter was set to 0.40 mm, the extrusion speed to 15 mm / s, and the printing temperature to 25°C. A 1×1×1 cm cube, a Superman icon, and a maple leaf were printed to evaluate the emulsion's printing performance.

[0100] Depend on Figure 7 It can be seen that Comparative Examples 1, 2, and 3 all demonstrate that the printing effect of Example 1 is better than that of Example 2, exhibiting better 3D printing formability, support, and solidity. The 3D printing effect is correlated with the particle size of the preceding Experimental Example 2; smaller particle size results in better 3D printing. The emulsion prepared from the composite of soy protein isolate and enzymatically hydrolyzed octenyl succinic acid starch exhibits superior adaptability to extreme environments and can still be used for 3D printing applications under extreme conditions.

[0101] Depend on Figure 8It can be seen that the small cubes printed in Example 3 have high precision, smooth surfaces, and no collapse. In contrast, the emulsion in Example 4 has an unclear interlayer structure in the lower layer, slight collapse at the top, and poor resistance to deformation. The Superman icon and maple leaf shapes printed by both samples are complete, with the emulsion in Example 3 having clearer edges. In two-color printing, the emulsion in Example 3 exhibits higher integrity, with no obvious fusion between the astaxanthin-encapsulated emulsion and the unencapsulated emulsion, demonstrating higher printing precision.

[0102] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of this application.

Claims

1. A method for preparing a waxy corn starch-based astaxanthin Pickering emulsion, characterized in that, Includes the following steps: (1) Add starch to octenyl succinic anhydride for esterification to obtain octenyl succinic starch. After enzymatic hydrolysis with high-temperature α-amylase, enzymatically hydrolyzed octenyl succinic starch is obtained. It is dissolved separately with soy protein isolate and compounded to obtain a complex solution. Astaxanthin is placed in soybean oil and stirred thoroughly to obtain the oil phase. (2) The oil phase and water phase were mixed in a ratio of 3:1 and dispersed at high speed to obtain a high internal phase Pickering emulsion containing astaxanthin. The emulsion was subjected to different temperatures and different ultraviolet irradiation times to obtain high internal phase Pickering emulsions with different temperature treatments and different ultraviolet irradiation times. (3) Adjust the pH, salt ion concentration and temperature respectively, and prepare high internal phase Pickering emulsion according to step (2) to obtain samples under different pH, salt ion and temperature conditions.

2. The method for preparing a waxy corn starch-based astaxanthin Pickering emulsion according to claim 1, characterized in that: In step (1), the starch includes waxy corn starch, ordinary corn starch, tapioca starch or potato starch.

3. The method for preparing a waxy corn starch-based astaxanthin Pickering emulsion according to claim 1, characterized in that: In step (1), the esterification reaction starch milk concentration is 35% w / w dry basis, the reaction time is 3-5 h, and the reaction pH is 8.0-8.

5.

4. The method for preparing a waxy corn starch-based astaxanthin Pickering emulsion according to claim 1, characterized in that: In step (1), the enzymatic hydrolysis temperature is 96℃, the enzyme dosage is 10-100U / g dry starch, and the enzymatic hydrolysis time is 5-60min.

5. The method for preparing a waxy corn starch-based astaxanthin Pickering emulsion according to claim 1, characterized in that: In step (1), the concentration of enzymatically hydrolyzed octenyl succinic acid starch and soy protein isolate is 0.5% to 5%, the ratio is 1:5 to 5:1, and the amount of astaxanthin added is 0.005% to 0.1% w / v.

6. The method for preparing a waxy corn starch-based astaxanthin Pickering emulsion according to claim 1, characterized in that: In step (2), the high-speed dispersion conditions are 10000-15000 rad / min for 0.5-3 min, temperature 4℃-70℃, treatment for 10-30 min, and ultraviolet irradiation time for 0-30 h.

7. The method for preparing a waxy corn starch-based astaxanthin Pickering emulsion according to claim 1, characterized in that: In step (3), the pH is adjusted to 2-11, the salt ion concentration is 0-1000 mmol, and the temperature is 4-100℃.

8. A high internal phase Pickering emulsion is prepared by the method according to any one of claims 1 to 7.

9. The application of the high internal phase Pickering emulsion according to claim 8 in the encapsulation and delivery of astaxanthin bioactive substances.

10. The application of the high internal phase Pickering emulsion according to claim 8 in 3D printed food.

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