A high internal phase emulsion with 3D printable and high freeze-thaw properties and application in mayonnaise

Abstract

The application discloses a high internal phase emulsion with 3D printing and high freeze-thaw characteristics and application thereof in salad dressing. The application comprises the following steps: S1, preparing edible protein as raw material to form a water phase with a concentration of 50-150 mg / ml; S2, using edible oil as an oil phase, adding the oil phase into the water phase, and using a homogenizer to act on the mixture at 5000-16000 rpm for 30 s-180 s to form a high internal phase emulsion; and S3, adding the obtained high internal phase emulsion into a certain amount of rennet, using a homogenizer to act on the mixture at no more than 6000 rpm for 30 s-180 s, and standing at 40 DEG C for 20 min. The high internal phase emulsion prepared by the application has 3D printing performance and high freeze-thaw stability, can remain highly stable after five freeze-thaw cycles, and is a 3D printing technology with high freeze-thaw stability, low operation cost, simple use, short cycle, and easy industrialization.

Description

Technical Field

[0001] This invention relates to the field of food processing technology, specifically to a high internal phase milk that can be 3D printed and has high freeze-thaw properties, and its application in salad dressings. Background Technology

[0002] High internal phase emulsions (HIPEs) refer to emulsions with a dispersed phase volume of 74.05% or higher, and they have broad application prospects in food processing, replacing solid or semi-solid oils. Currently, HIPEs stabilized by protein particles as emulsifiers occupy an important position among food-grade HIPEs and are a safe, edible 3D printing material with good development prospects. Using protein HIPEs for 3D printing requires the emulsion to have suitable hardness and viscosity to ensure self-support and extrusion continuity during printing. Currently, the number of 3D-printable edible HIPEs is limited, and not all protein-stabilized HIPEs are 3D-printable, severely restricting the application of various proteins in food 3D printing. Furthermore, while freezing food can maximize its freshness, nutritional value, and original flavor, for 3D-printable food-grade HIPEs stabilized by protein particles as emulsifiers, the aqueous phase easily forms sharp ice crystals after freezing, damaging the interfacial structure. This thermodynamic instability makes it prone to flocculation, aggregation, and oil-water separation after thawing, which reduces the quality of food emulsions and greatly reduces the application of high-protein internal phase emulsions in food. Therefore, it is very important to solve the problem of freeze-thaw stability of 3D printable emulsions. Summary of the Invention

[0003] The technical problem that this invention aims to solve is:

[0004] 1. Currently, there are few food-grade high internal phase emulsions that can be 3D printed, and not all protein-stable high internal phase emulsions have 3D printing capabilities. This invention can provide a simple method for 3D printing high internal phase emulsions.

[0005] 2. Most existing 3D-printable high internal phase emulsions lack freeze-thaw stability; after freezing, the oil phase leaks out due to emulsification. Therefore, there is a lack of simple, low-cost 3D-printable high internal phase emulsions with high freeze-thaw stability.

[0006] This invention provides a method for preparing a high-internal-phase emulsion that can be 3D printed and has high freeze-thaw properties, which solves the above problems, and includes the following steps:

[0007] S1. Mix egg white with water, stir, and prepare an egg white solution;

[0008] S2. Mix the protein solution described in step S1 with oil to obtain an oil-water mixture;

[0009] S3. Homogenize the oil-water mixture described in step S2 to obtain a high internal phase emulsion;

[0010] S4. Add the enzyme to the high internal phase emulsion prepared in S3, stir and let stand to obtain a high internal phase emulsion that can be 3D printed and has high freeze-thaw properties.

[0011] Furthermore, the protein mentioned in step S1 is one or more of casein, soy protein, whey protein isolate, peanut protein, and pea protein.

[0012] Preferably, the protein in step S1 is casein.

[0013] Furthermore, the mass-to-volume ratio of protein to water in step S1 is 0.5–1.5 g: 10 mL.

[0014] Furthermore, the stirring time in step S1 is 5 to 12 hours.

[0015] Furthermore, the pH adjustment in step S1 involves first adjusting the protein solution to pH 9-10 using NaOH solution, and then adjusting the protein solution to pH 6.5-7.5 using HCl solution.

[0016] Furthermore, the oil mentioned in step S2 is a vegetable oil.

[0017] Preferably, the oil mentioned in step S2 is soybean oil.

[0018] Furthermore, the volume ratio of the protein solution to the oil in step S2 is 1:3 to 5.

[0019] Furthermore, the homogenization in step S3 is performed at 7000–9000 r / min for 80–100 s.

[0020] Furthermore, the enzyme mentioned in step S3 is one or more of chymotrypsin, TG enzyme, trypsin, and pepsin.

[0021] Preferably, the enzyme in step S3 is rennet.

[0022] Furthermore, the mass-to-volume ratio of the enzyme and the high internal phase emulsion in step S3 is 0.01–0.4 g: 20 mL.

[0023] Preferably, the mass-to-volume ratio of the enzyme and the high internal phase emulsion in step S3 is 0.01–0.1 g: 20 mL.

[0024] Specifically, optionally, the mass-to-volume ratio of the enzyme and the high internal phase emulsion in step S3 is 0.1 g: 20 mL.

[0025] Furthermore, the stirring and settling in step S3 involves using a homogenizer at 3000-4000 rpm for 20-30 seconds and then settling at 30-37°C for 15-20 minutes to stabilize.

[0026] This invention provides a high internal phase emulsion that is 3D printable and has high freeze-thaw properties, prepared according to the above method.

[0027] The present invention provides the application of high internal phase milk with 3D printability and high freeze-thaw properties in the food industry.

[0028] This invention provides a method for preparing a salad dressing with high freeze-thaw properties, comprising the following steps:

[0029] Take the high internal phase milk prepared above, edible salt, onion juice, diced pickled cucumbers, diced potatoes, minced shark, chopped hard-boiled eggs, chopped celery, and white pepper powder, and mix well to obtain a salad dressing with high freeze-thaw properties.

[0030] Furthermore, the components of the high freeze-thaw properties salad dressing, by weight, are: 140-150 parts high internal phase milk, 1-3 parts salt, 5-10 parts onion juice, 10-15 parts diced pickles, 1-4 parts diced potatoes, 8-10 parts minced shark, 0.5-1 part chopped hard-boiled eggs, 1-2 parts chopped celery, and 0.1-0.5 parts white pepper powder.

[0031] Compared with the prior art, the present invention has the following beneficial effects:

[0032] 1. The high internal phase emulsion prepared by this invention can be used for 3D printing and has high extrudability and self-support, thus expanding the application scope of high internal phase emulsion in the field of food 3D printing.

[0033] 2. The preparation method of the present invention can utilize different types of proteins to prepare food-grade 3D printing materials, improve the economic value of various proteins, and meet people's needs for healthy, safe, and nutritious 3D printed foods.

[0034] 3. The preparation method of the present invention can solve the problem of the stability of emulsion under repeated freeze-thaw cycles, and meet the actual needs of low-temperature storage and long-term transportation.

[0035] 4. The key to the application of this invention in 3D printing is the use of rennet to improve the rheological properties of the emulsion, thereby giving it 3D printing characteristics. Under the cross-linking action of rennet, a gel network is formed, which restricts the formation and growth of ice crystals, thereby improving the freeze-thaw stability of the emulsion.

[0036] 5. The high freeze-thaw properties of the high internal phase emulsion prepared by this invention can be applied in the field of salad dressing preparation, which can solve the problem of frozen storage of salad dressing and ensure that salad dressing has freeze-thaw stability. Attached Figure Description

[0037] Figure 1 This is an appearance diagram of the high internal phase emulsion obtained in Example 1 of the present invention before freeze-thaw.

[0038] Figure 2 These are images of the protein high internal phase emulsion obtained in Example 1 of this invention, after 1, 3, and 5 freeze-thaw cycles (from left to right).

[0039] Figure 3 This is an image of the 3D-printed food obtained in Example 1 of the present invention before freezing and thawing.

[0040] Figure 4 These are the appearance images of the 3D printed food obtained in Embodiment 1 of the present invention after 1, 3, and 5 cycles of freeze-thaw (from left to right).

[0041] Figure 5 This is an appearance diagram of the high internal phase emulsion obtained in Example 2 of the present invention before freeze-thaw.

[0042] Figure 6 These are images of the protein high internal phase emulsion obtained in Example 2 of this invention after 1, 3, and 5 freeze-thaw cycles (from left to right).

[0043] Figure 7 This is an image of the 3D-printed food obtained in Embodiment 2 of the present invention before freezing and thawing.

[0044] Figure 8 These are the appearance images of the 3D printed food obtained in Embodiment 2 of the present invention after 1, 3, and 5 cycles of freeze-thaw (from left to right).

[0045] Figure 9 This is an appearance diagram of the high internal phase emulsion obtained in Example 3 of the present invention before freeze-thaw.

[0046] Figure 10 These are images of the protein high internal phase emulsion obtained in Example 3 of this invention after 1, 3, and 5 freeze-thaw cycles (from left to right).

[0047] Figure 11 This is an image of the 3D-printed food obtained in Example 3 of the present invention before freezing and thawing.

[0048] Figure 12 These are the appearance images of the 3D printed food obtained in Embodiment 3 of the present invention after 1, 3, and 5 cycles of freeze-thaw (from left to right).

[0049] Figure 13 This is an image of the high internal phase emulsion obtained in Comparative Example 1 of the present invention before freeze-thaw cycles.

[0050] Figure 14 These are images of the protein high internal phase emulsion obtained in Comparative Example 1 of this invention after 1, 3, and 5 freeze-thaw cycles (from left to right).

[0051] Figure 15 This is an image of the 3D-printed food obtained in Comparative Example 1 of this invention, before freezing and thawing.

[0052] Figure 16 These are the appearance images of the 3D printed food obtained in Comparative Example 1 of this invention after 1, 3, and 5 cycles of freeze-thaw (from left to right).

[0053] Figure 17 This is an appearance diagram of the high internal phase emulsion obtained in Comparative Example 2 of the present invention before freeze-thaw.

[0054] Figure 18 These are images of the protein high internal phase emulsion obtained in Comparative Example 2 of this invention after 1, 3, and 5 freeze-thaw cycles (from left to right).

[0055] Figure 19 This is an image of the 3D-printed food obtained in Comparative Example 2 of this invention, before freezing and thawing.

[0056] Figure 20 These are the appearance images of the 3D printed food obtained in Comparative Example 2 of this invention after 1, 3, and 5 cycles of freeze-thaw (from left to right).

[0057] Figure 21 The images show the appearance of the protein high internal phase emulsion prepared by glutamine transaminase in Comparative Example 3 of this invention after 1, 3, and 5 freeze-thaw cycles (from left to right).

[0058] Figure 22 The images show the appearance of the protein high internal phase emulsion obtained by trypsin preparation in Comparative Example 3 of this invention after 1, 3, and 5 freeze-thaw cycles (from left to right).

[0059] Figure 23 The images show the appearance of the protein high internal phase emulsion obtained by pepsin preparation in Comparative Example 3 of this invention after 1, 3, and 5 freeze-thaw cycles (from left to right). Detailed Implementation

[0060] The present invention will be further illustrated below with specific implementation examples, but the implementation of the present invention is not limited thereto.

[0061] Raw material sources: Rennet: Macklin R92600, rennet activity ≥20u / mg; Trypsin: Macklin, enzyme activity 250u / mg; Pepsin: Macklin, 15000NFu / g; Transglutaminase: 100U / g; Soybean oil: JD Supermarket Golden Dragon Soybean Vegetable Oil; Casein: Aladdin. Unless otherwise specified, the 3D printer model used in the following examples is FPE2, brand: Shanghai Fuqifanji Desktop Rapid Prototyping Machine.

[0062] Example 1

[0063] S1. Preparation of casein solution: Weigh 4g of casein and mix it with 40mL of water to prepare a protein solution. Stir for 10h to obtain casein solution A. Then use 1mol / L NaOH to adjust the pH of casein solution A to 10, so that the casein is completely dissolved in water to obtain casein solution B. Then use 1mol / L HCl to adjust the pH of casein solution B to 7 to obtain casein solution C.

[0064] S2. Preparation of oil-water mixture: The casein solution C described in step S1 is mixed with soybean oil at a volume ratio of 1:4 to obtain an oil-water mixture;

[0065] S3. Preparation of high internal phase emulsion: Homogenize the oil-water mixture described in step S2 at 8000 r / min for 90 s to obtain a high internal phase emulsion;

[0066] S4. Add 0.1g of rennet to 20ml of the high internal phase emulsion prepared in S3, homogenize it at 3000rpm for 30s, and let it stand at 37℃ for 20min to obtain a homogeneous emulsion.

[0067] S5. The homogeneous emulsion described in step S4 is loaded into the filling tank of the 3D printer for 3D printing. The parameters are: nozzle diameter of 1 mm, platform movement speed of 20 mm / s, and extrusion rate of 1 mm / s. 3 ·s 1 A cylinder with a height of 20mm and a diameter of 20mm is printed to obtain 3D printed food.

[0068] The high internal phase emulsion from step S4 of Example 1 was subjected to freeze-thaw cycle testing. Testing procedure: 10g of the high internal phase emulsion was added to a 10mL centrifuge tube, frozen at -28℃ for 24h, and then heated in a water bath at 37℃ for 2h to complete one freeze-thaw cycle.

[0069] Figure 1 This is an image of the centrifuge tube containing the emulsion in this embodiment, before it has been frozen and thawed. Figure 2 The images show the appearance after one freeze-thaw cycle, three freeze-thaw cycles, and five freeze-thaw cycles. It can be seen that the emulsion remains stable after five freeze-thaw cycles, with no significant changes in the emulsion system and no obvious demulsification, indicating that the emulsion has good freeze-thaw stability.

[0070] The 3D printed food obtained in step S5 is as follows: Figure 3 As shown, the resulting product has clear edges and strong self-supporting ability. The 3D-printed food obtained in step S5 of Example 1 was subjected to freeze-thaw cycle testing. Testing steps: The 3D-printed food was frozen at -28℃ for 24 hours, then subjected to a 37℃ water bath for 2 hours, constituting one freeze-thaw cycle.

[0071] The results are as follows Figure 4As shown, the original structure was maintained after three freeze-thaw cycles, with no oil phase precipitation. After five freeze-thaw cycles, a small amount of oil phase precipitated, but the overall printed structure remained unchanged. This may be because the emulsion underwent high shear when passing through the 1mm nozzle, which affected the emulsion and led to the precipitation of a small amount of oil phase.

[0072] The high internal phase emulsion from step S4 of Example 1 was subjected to rheological testing. The rheological testing method was as follows: A TADiscovery HR-2 rheometer equipped with parallel plate geometry (40 mm diameter, 1 mm plate gap) was used at 25°C. Frequency scanning was performed at 0.5% strain to measure the storage modulus (G′) and loss modulus (G”).

[0073] The results are shown in Table 1. The storage modulus G' is much greater than the loss modulus G". The results indicate that the protein O / W high internal phase emulsion prepared in this embodiment is close to a solid state. At the same time, the value of the storage modulus G' indicates that the protein O / W high internal phase emulsion prepared in this embodiment has high hardness and self-support for printing, making it suitable for 3D printing.

[0074] Table 1 Rheological test data

[0075]

[0076]

[0077]

[0078] Example 2

[0079] The preparation was carried out according to the steps of Example 1, except that the amount of rennet in step S4 was changed to 0.05g, while other operating parameters remained unchanged.

[0080] The high internal phase emulsion from step S4 of Example 2 was subjected to freeze-thaw cycle testing, and the testing steps were the same as those in Example 1.

[0081] Figure 5 This is an image of the centrifuge tube containing the emulsion in this embodiment, before it has been frozen and thawed. Figure 6 The images show the appearance after one freeze-thaw cycle, three freeze-thaw cycles, and five freeze-thaw cycles. After three freeze-thaw cycles, the emulsion system showed no significant changes, no oil layer precipitation on the surface, and no demulsification, indicating that the emulsion has good freeze-thaw stability. After five freeze-thaw cycles, some oil-emulsion stratification appeared at the bottom of the emulsion. This indicates that the decrease in rennet content has a certain impact on the freeze-thaw stability of the emulsion.

[0082] The 3D printed food obtained in step S5 of Example 2 is as follows: Figure 7As shown, the resulting product has clear edges and strong self-supporting ability. The 3D-printed food was subjected to freeze-thaw cycle testing, following the same testing steps as in Example 1.

[0083] The results are as follows Figure 8 As shown, the printed structure maintained its original structure after three freeze-thaw cycles, with no oil phase precipitation. However, after five freeze-thaw cycles, the printed structure showed significant collapse.

[0084] The high internal phase emulsion from step S4 of Example 2 was subjected to rheological testing, and the method of rheological testing was the same as that in Example 1.

[0085] The results are shown in Table 2. The storage modulus G' is much greater than the loss modulus G". The results indicate that the protein O / W high internal phase emulsion prepared in this embodiment is close to a solid state. At the same time, the value of the storage modulus G' indicates that the protein O / W high internal phase emulsion prepared in this embodiment has high stiffness and self-support.

[0086] The emulsion prepared in step S4 of this embodiment was used for 3D printing. The resulting 3D printed food is shown in the figure. The product has clear edges, strong self-support, and does not collapse or cave in. Therefore, it is demonstrated that the protein O / W high internal phase emulsion prepared in this embodiment can be used for 3D printing. Furthermore, it maintains its original structure after three freeze-thaw cycles without oil phase precipitation. However, after five freeze-thaw cycles, the printed structure showed significant collapse.

[0087] Table 2 Rheological test data

[0088]

[0089]

[0090]

[0091] Example 3

[0092] The preparation was carried out according to the steps of Example 1, except that the amount of rennet in step S4 was changed to 0.01g, while other operating parameters remained unchanged.

[0093] The high internal phase emulsion from step S4 of Example 3 was subjected to freeze-thaw cycle testing, and the testing steps were the same as in Example 1.

[0094] Figure 9 This is an image of the centrifuge tube containing the emulsion in this embodiment, before it has been frozen and thawed. Figure 10 These are the appearance images after one freeze-thaw cycle, three freeze-thaw cycles, and five freeze-thaw cycles. The resulting products exhibited collapse or subsidence, indicating that the 3D printing effect of the emulsion worsens as the amount of rennet added gradually decreases. Furthermore, the emulsion completely decomposed after five freeze-thaw cycles.

[0095] The 3D printed food obtained in step S5 of Example 3 is as follows: Figure 11 As shown, the resulting product has clear edges and strong self-supporting ability. The 3D-printed food was subjected to freeze-thaw cycle testing, following the same testing steps as in Example 1.

[0096] The results are as follows Figure 12 As shown, after one freeze-thaw cycle, compared with Examples 1 and 2, the emulsion showed obvious demulsification. After five freeze-thaw cycles, the oil and water phases of the emulsion were completely separated.

[0097] The high internal phase emulsion from step S4 of Example 3 was subjected to rheological testing, and the method of rheological testing was the same as that in Example 1.

[0098] The results are shown in Table 3. The storage modulus G' is much greater than the loss modulus G". The results indicate that the protein O / W high internal phase emulsion prepared in this example is close to a solid state. However, compared with Examples 1 and 2, the storage modulus is significantly reduced, indicating that the hardness and support of the emulsion decrease with the decrease of rennet amount.

[0099] Table 3 Rheological test data

[0100]

[0101]

[0102] Comparative Example 1

[0103] S1. Preparation of casein solution: Weigh 4g of casein and mix it with 40mL of water to prepare a protein solution. Stir for 10h to obtain casein solution A. Then use 1mol / L NaOH to adjust the pH of casein solution A to 10, so that the casein is completely dissolved in water to obtain casein solution B. Then use 1mol / L HCl to adjust the pH of casein solution B to 7 to obtain casein solution C.

[0104] S2. Preparation of oil-water mixture: The casein solution C described in step S1 is mixed with soybean oil at a volume ratio of 1:4 to obtain an oil-water mixture;

[0105] S3. Preparation of high internal phase emulsion: Homogenize the oil-water mixture described in step S2 at 8000 r / min for 90 s to obtain a high internal phase emulsion;

[0106] S4. 3D Printing: The high internal phase emulsion described in step S3 is loaded into the filling tank of a 3D printer for 3D printing. The parameters are: nozzle diameter 1mm, platform movement speed 20mm / s, and extrusion rate 1mm. 3 ·s 1 3D printed food can be obtained.

[0107] The high internal phase emulsion from step S3 of Comparative Example 1 was subjected to freeze-thaw cycle testing, and the testing steps were the same as in Example 1.

[0108] Figure 13 This is a diagram showing the appearance of centrifuge tubes containing emulsion in this comparative example, before they have been frozen and thawed. Figure 14 The images show the appearance after one freeze-thaw cycle, three freeze-thaw cycles, and five freeze-thaw cycles. After one freeze-thaw cycle, an oil layer precipitates at the bottom of the emulsion system. After three to five freeze-thaw cycles, almost all the oil phase in the emulsion precipitates, indicating that the emulsion without rennet induction does not possess freeze-thaw stability.

[0109] The 3D printed food obtained in Comparative Example 1, such as Figure 15 As shown, the resulting cylindrical product collapsed, lacking self-supporting ability. The 3D-printed food was subjected to freeze-thaw cycle testing, following the same testing steps as in Example 1.

[0110] The results are as follows Figure 16 As shown, the oil phase precipitates directly after one freeze-thaw cycle, and almost all of the oil phase precipitates after 3 to 5 cycles.

[0111] Rheological tests were performed on the high internal phase emulsion from step S3 of Comparative Example 1, using the same method as in Example 1.

[0112] The results are shown in Table 4. The storage modulus G' is much greater than the loss modulus G". The results indicate that the protein O / W high internal phase emulsion prepared in this example is close to a solid state. However, compared with Examples 1, 2, and 3, its storage modulus is significantly lower, and its hardness and self-support are weaker. The high internal phase emulsion prepared in this comparative example was subjected to freeze-thaw cycling treatment.

[0113] Table 4 Rheological test data

[0114]

[0115]

[0116]

[0117] Comparative Example 2

[0118] The preparation was carried out according to the steps of Example 1, except that the amount of rennet in step S4 was changed to 0.4g, while other operating parameters remained unchanged.

[0119] The high internal phase emulsion from step S4 of Comparative Example 2 was subjected to freeze-thaw cycle testing, and the testing steps were the same as those in Example 1.

[0120] Figure 17 This is a diagram showing the appearance of centrifuge tubes containing emulsion in this comparative example, before they have been frozen and thawed. Figure 18The images show the appearance after one freeze-thaw cycle, three freeze-thaw cycles, and five freeze-thaw cycles. After one freeze-thaw cycle, an oil layer precipitates at the top of the emulsion system. After three to five freeze-thaw cycles, almost all the oil phase in the emulsion precipitates, indicating that the emulsion induced by excessive addition of rennet does not possess freeze-thaw stability.

[0121] Comparative Example 2: 3D printed food such as Figure 19 As shown, the cylinder collapsed, indicating poor self-support. This suggests that the amount of rennet added was too high, and the high protein O / W internal phase milk after induction treatment is unsuitable for 3D printing. The 3D-printed food was subjected to freeze-thaw cycle testing, following the same testing procedures as in Example 1.

[0122] The results are as follows Figure 20 As shown, the oil phase precipitates directly after one freeze-thaw cycle, and almost all of the oil phase precipitates after 3 to 5 cycles.

[0123] Rheological tests were performed on the high internal phase emulsion from step S4 of Comparative Example 2, using the same method as in Example 1.

[0124] The results are shown in Table 5. The storage modulus G' is much greater than the loss modulus G". The results indicate that the protein O / W high internal phase emulsion prepared in this example is close to a solid state. However, compared with Examples 1, 2, and 3, its storage modulus is significantly lower, and its hardness and self-support are weaker. Excessive enzyme addition will affect the stability of the emulsion and thus its rheological properties.

[0125] Table 5 Rheological test data

[0126]

[0127]

[0128]

[0129] Comparative Example 3

[0130] The preparation was carried out according to the steps of Example 2, except that the rennet in step S4 was replaced with TG enzyme, trypsin, and pepsin, respectively, while other operating parameters remained unchanged.

[0131] The high internal phase emulsion obtained in step S4 of this comparative example was subjected to freeze-thaw cycling. For example... Figures 21-23 As shown, after one freeze-thaw cycle, oil layers precipitated in the emulsions induced by the other two enzymes besides pepsin. After 3 to 5 freeze-thaw cycles, the oil phase in the emulsions stabilized by the three enzymes basically showed obvious emulsion demulsification and oil phase precipitation, indicating that the emulsions induced by other enzymes have freeze-thaw stability, but their stability is worse than that of rennet.

[0132] Example 4

[0133] S1. Preparation of casein solution: Weigh 4g of casein and mix it with 40mL of water to prepare a protein solution. Stir for 10h to obtain casein solution A. Then use 1mol / L NaOH to adjust the pH of casein solution A to 10, so that the casein is completely dissolved in water to obtain casein solution B. Then use 1mol / L HCl to adjust the pH of casein solution B to 7 to obtain casein solution C.

[0134] S2. Preparation of oil-water mixture: The casein solution C described in step S1 is mixed with soybean oil at a volume ratio of 1:4 to obtain an oil-water mixture;

[0135] S3. Preparation of high internal phase emulsion: Homogenize the oil-water mixture described in step S2 at 8000 r / min for 90 s to obtain a high internal phase emulsion;

[0136] S4. Add 0.1g of rennet to 20ml of the high internal phase emulsion prepared in S3, homogenize it at 3000rpm for 30s, and let it stand at 37℃ for 20min to obtain a homogeneous emulsion.

[0137] S5. Take 150g of the homogeneous emulsion prepared in S4, 3g of salt, 10g of onion juice, 15g of diced pickled cucumber, 4g of diced cooked potato, 10g of chopped shark, 1 chopped hard-boiled egg, 2g of chopped celery, and a pinch of white pepper powder. Mix well to obtain a salad dressing with high freeze-thaw properties.

[0138] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A method for preparing a high-internal-phase emulsion that is 3D printable and has high freeze-thaw properties, characterized in that, Including the following steps: S1. Mix egg white with water and stir to prepare an egg white solution; the egg white is casein; the mass-to-volume ratio of the egg white to water is 0.5~1.5 g:10 mL; S2. Mix the protein solution obtained in step S1 with oil to obtain an oil-water mixture; the volume ratio of the protein solution to the oil is 1:3~5. S3. Homogenize the oil-water mixture described in step S2 to obtain a high internal phase emulsion; S4. Add the enzyme to the high internal phase emulsion prepared in S3, stir and let stand to obtain a high internal phase emulsion that can be 3D printed and has high freeze-thaw properties; the enzyme is rennet; the mass-volume ratio of the enzyme to the high internal phase emulsion is 0.01~0.1 g:20 mL.

2. The method according to claim 1, characterized in that, In step S1, the protein solution is first adjusted to pH 9-10 using NaOH solution, and then adjusted to pH 6.5-7.5 using HCl solution.

3. The method according to claim 1, characterized in that, The oil mentioned in step S2 is vegetable oil.

4. A high internal phase emulsion with high freeze-thaw properties that can be 3D printed.

5. The application of the high internal phase milk with 3D printability and high freeze-thaw properties as described in claim 4 in the food industry.

6. A method for preparing a salad dressing with high freeze-thaw properties, comprising the following steps: Take the high internal phase emulsion with high freeze-thaw properties that is 3D printable as described in claim 5, edible salt, onion juice, diced pickles, diced potatoes, minced shark, diced hard-boiled eggs, diced celery, and white pepper powder, mix them evenly to obtain a salad dressing with high freeze-thaw properties.

7. The method according to claim 6, characterized in that, The components of a salad dressing with high freeze-thaw properties, by weight, are: 140-150 parts high internal phase milk, 1-3 parts salt, 5-10 parts onion juice, 10-15 parts diced pickles, 1-4 parts diced potatoes, 8-10 parts minced shark, 0.5-1 part chopped hard-boiled eggs, 1-2 parts chopped celery, and 0.1-0.5 parts white pepper powder.

Images