Low-fat gel type Pickering two-phase emulsion foam, preparation method thereof and application of low-fat gel type Pickering two-phase emulsion foam in dual-nutrient loading and 3D printing

Abstract

The invention discloses low-fat gel type Pickering two-phase emulsion foam, a preparation method thereof and application of the low-fat gel type Pickering two-phase emulsion foam in dual-nutrient loading and 3D printing, and belongs to the technical field of grease and emulsified fat products. The prepared gel type Pickering two-phase emulsion foam does not contain any synthetic surfactant and trans fatty acid, multi-cavity emulsion droplet and bubble structures coexist, and multi-interface Pickering stabilization endows the system with excellent stability and good plasticity and thermal reversibility. Besides, the foam system can realize high-efficiency co-loading of nutrients, the nutrient co-loading system shows good application potential in 3D printing, high printing precision and high nutrient retention efficiency can be realized, and the performance of a 3D printing object can be adjusted by adjusting the type and content of used fat, so that the 3D printing effect is improved. The development and multifunctional application of healthy and nutritional aerated steady-state fat-based food (non-dairy cream, single cream, ice cream and the like) are greatly widened.

Description

Technical Field

[0001] The invention belongs to the technical field of oils and emulsified fat products, and in particular relates to a low-fat gel-type Pickering two-phase emulsion foam, a preparation method thereof, and applications in dual-nutrient loading and 3D printing. Background Art

[0002] Excessive fat intake will increase the risk of certain chronic diseases in humans. Therefore, people's demand for healthy diet and low-calorie food is growing. If the fat content in food is simply reduced, the taste of fatty food will be greatly reduced, and consumers will find it difficult to accept. It is of great significance to reduce the fat content in fatty food without affecting the taste and texture to meet people's growing demand for healthy diet and low-calorie food.

[0003] The O1 / W / O2 emulsion system has a complex structure and unique properties, and has great application potential in the food field. The oil content of the edible two-phase fat emulsion can also be adjusted according to actual production needs. Therefore, if micron or millimeter-level air bubbles can be introduced into the two-phase emulsion at the same time, it can provide a new direction for the development of healthy aerated foods (margarine, whipped cream, ice cream, etc.). It can not only create novel textures and flavors, but also enable people to get a sense of fullness while reducing energy intake, providing more possibilities for the design of food materials. In addition, the current food industry is committed to designing multiple phases into the same system so that it has superimposed functional characteristics.

[0004] Currently, the production of two-phase emulsions and foams usually relies on large amounts of synthetic emulsifiers (such as polyglycerol polyricinoleate, PGPR). For the sake of consumer health, it is necessary to reduce or replace surfactants with natural food materials, which can help provide clean label foods. At the same time, systems stabilized by edible particles are more advantageous and can provide superior stability to the system. Therefore, it is of great significance to design a new type of ultra-stable fat analog with good plasticity, diverse functions, and multi-chamber emulsion droplets and bubbles.

[0005] In the food sector, combined nutrition is becoming a hot topic. For example, epigallocatechin gallate (EGCG, hydrophilic) and lycopene (hydrophobic) have been shown to have synergistic effects in disease prevention and health promotion. However, both have limitations in nutritional functional components, such as poor solubility in water or oil and sensitivity to the environment, making them challenging to incorporate into food formulations. The foam system of two-phase emulsions can effectively solve the above obstacles as a new co-carrier system. In addition, 3D food printing has the ability to develop customized products to meet specific dietary needs and preferences, and has been widely used in the food field in recent years. Expanding the scope of 3D printing in clean label and nutritionally sound fat products is an effort worth encouraging. Summary of the invention

[0006] The purpose of this section is to summarize some aspects of embodiments of the present invention and briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this section and the specification abstract and the invention title of this application to avoid blurring the purpose of this section, the specification abstract and the invention title, and such simplifications or omissions cannot be used to limit the scope of the present invention.

[0007] At present, the main problems with fat foods are that they are unhealthy, lack functionality, and have a bad taste. Therefore, it is of great significance to design microstructures with explicit and implicit multifunctionality for the development of new fat foods to meet consumers' nutritional, health and taste needs, such as increasing health benefits, improving resource sustainability, increasing the use of plant protein, and personalized applications. At present, the preparation and related research of plastic gel-type two-phase emulsion foam systems have not been involved, and the traditional method of preparing multiphase systems usually requires the introduction of a certain amount of synthetic or non-synthetic small molecule emulsifiers to stabilize different interfaces, which usually have problems such as being unnatural, poor stability, low plasticity, and limited functionality.

[0008] In view of the above problems and / or the problems existing in the prior art, the present invention is proposed.

[0009] Therefore, the purpose of the present invention is to overcome the deficiencies in the prior art and provide a method for preparing a low-fat gel-type Pickering two-phase emulsion foam. The obtained gel-type Pickering two-phase emulsion foam has coexistence of multi-chamber droplets and bubble structures, does not contain any synthetic emulsifier, does not contain trans fatty acids, multiple interfaces all achieve Pickering stabilization, has a soft and delicate texture, and good plasticity, and can be further used for the co-loading of hydrophilic and hydrophobic nutrients, and realizes 3D printing of nutritional whipping and aeration systems, thereby achieving diversified application scenarios.

[0010] In order to solve the above technical problems, the present invention provides the following technical solutions: comprising:

[0011] Adding liquid vegetable oil to the aqueous solution of vegetable protein gel particles, shearing and emulsifying, to obtain an O / W type primary emulsion;

[0012] The high melting point fat is mixed with the liquid vegetable oil, heated to melt, and partially crystallized in an ice bath, the obtained O / W type primary emulsion is added thereto, sheared and homogenized, and then continued to stand and cool in an ice bath to obtain a gel type O / W / O two-phase emulsion;

[0013] The gel-type O / W / O two-phase emulsion is stored for a period of time and then whipped at room temperature to obtain a low-fat gel-type Pickering two-phase emulsion foam with coexistence of multi-chamber emulsion droplets and bubble structures;

[0014] Among them, the addition amount of the liquid vegetable oil is 5% to 35% of the O / W / O two-phase emulsion, the addition amount of the plant protein gel particle aqueous solution is 10% to 70% of the O / W / O two-phase emulsion, the mass ratio of the high melting point oil and liquid vegetable oil after mixing in the O / W / O two-phase emulsion is 25% to 85%, and the concentration of the plant protein gel particle aqueous solution is 0.5% to 3%.

[0015] As a preferred embodiment of the method for preparing the low-fat gel-type Pickering two-phase emulsion foam of the present invention, the liquid vegetable oil comprises one of soybean oil, rapeseed oil, peanut oil, sunflower seed oil, rice bran oil, corn oil, linseed oil, olive oil, wheat germ oil, cottonseed oil, almond oil, tea seed oil and sesame oil; the high melting point oil is one or more of milk fat, palm oil, palm kernel oil, palm stearin, coconut oil, cocoa butter, shea butter, balsam pear resin, mango kernel oil and ice grass fat.

[0016] As a preferred embodiment of the method for preparing the low-fat gel-type Pickering two-phase emulsion foam of the present invention, the method for preparing the plant protein gel particles comprises:

[0017] A 5% to 20% mass concentration of vegetable protein aqueous solution is fully hydrated at 0 to 4°C for 12 to 24 hours, the pH is adjusted to 7.0 to 7.5, and then subjected to heat denaturation and enzyme cross-linking treatment to obtain a vegetable protein gel, which is then crushed and homogenized to obtain nano-scale vegetable protein gel particles;

[0018] The plant protein includes one of soy protein isolate, peanut protein isolate, pea protein isolate, mung bean protein isolate, oat protein isolate, quinoa protein isolate, broad bean protein isolate, and potato protein isolate;

[0019] The heat denaturation is performed by heating at 80-100° C. for 0.5-4 h; the enzyme cross-linking is performed by using 2-5 U / g of transglutaminase at 40-45° C. for 2-5 h.

[0020] As a preferred embodiment of the method for preparing the low-fat gel-type Pickering two-phase emulsion foam of the present invention, the heating and melting conditions are heating at 50-80° C. for 30-60 min; and the partial crystallization time is 20-60 min.

[0021] As a preferred embodiment of the method for preparing the low-fat gel-type Pickering two-phase emulsion foam of the present invention, the shear emulsification conditions of the O / W colostrum are 8000-12000 rpm for 2-5 min; the shear emulsification conditions during the preparation of the gel-type O / W / O two-phase emulsion are 3000-5000 rpm for 2-8 min; and the static cooling time is 30-90 min.

[0022] As a preferred embodiment of the method for preparing the low-fat gel-type Pickering two-phase emulsion foam of the present invention, the storage condition is 15-25° C. for 12-24 hours, and the whipping is at 2000-4000 rpm for 4-10 minutes.

[0023] The object of the present invention is to overcome the deficiencies in the prior art and provide a low-fat gel-type Pickering two-phase emulsion foam, wherein the foam has a multi-chamber emulsion droplet and a bubble structure coexisting.

[0024] The purpose of the present invention is to overcome the deficiencies in the prior art and provide a low-fat gel-type Pickering two-phase emulsion foam for use in co-loading nutrients, comprising:

[0025] The hydrophilic nutrients and the hydrophobic nutrients are respectively added into the aqueous solution of the plant protein particles and the liquid edible vegetable oil, and after being evenly mixed, a low-fat gel-type Pickering two-phase emulsion foam is prepared.

[0026] As a preferred application scheme of the low-fat gel-type Pickering two-phase emulsion foam described in the present invention, the hydrophilic nutrient includes EGCG, the hydrophobic nutrient includes lycopene, and the added amount of the nutrient is 1-5 mg / mL.

[0027] The purpose of the present invention is to overcome the deficiencies in the prior art and provide an application of a low-fat gel-type Pickering two-phase emulsion foam in 3D printing.

[0028] Beneficial effects of the present invention:

[0029] (1) The present invention utilizes the ability of high melting point fat to form crystalline particles, and constructs a new type of low-fat gel-type Pickering two-phase emulsion foam based on plant protein and fat crystals, wherein the fat crystals can simultaneously stabilize the oil-in-water interface and the oil-in-gas interface, realizing multi-interface Pickering stabilization, and obtaining a multi-chamber emulsion structure and a system in which bubbles coexist. It does not involve any synthetic surfactants and chemical components, is green and safe, and conforms to the development trend of health. At the same time, it does not contain trans fatty acids, has a simple preparation process, a stable structure, a soft and delicate texture, and has excellent plasticity and decorating properties.

[0030] (2) Furthermore, the low-fat gel-type Pickering two-phase emulsion foam with coexisting multi-chamber droplets and bubble structures obtained by the present invention can be used for co-loading of hydrophilic and hydrophobic nutrients and 3D printing, achieving high-efficiency co-encapsulation of nutrients, and performing well in 3D printing with adjustable performance. After printing, the nutrients can be well retained, which greatly broadens the development and multifunctional application of new healthy, nutritious, aerated and stabilized fat-based foods. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work. Among them:

[0032] Figure 1 A flow chart of a method for preparing a low-fat gel-type Pickering two-phase emulsion foam with coexistence of multi-chamber droplets and bubble structures;

[0033] Figure 2 The microscopic images of the low-fat gel-type Pickering two-phase emulsion foam with coexistence of multi-chamber emulsion droplets and bubble structures obtained in Examples 1 to 3 include ordinary optical images (20×10), polarized images (20×10), and laser confocal microscopy images (50×10);

[0034] Figure 3 This is a physical appearance picture of the low-fat gel-type Pickering two-phase emulsion foam obtained in Examples 1 to 3;

[0035] Figure 4 The thermal reversible behavior process of low-fat gel-type Pickering two-phase emulsion foam;

[0036] Figure 5 The microscopic images of the low-fat gel-type Pickering two-phase emulsion foam with coexistence of multi-chamber emulsion droplets and bubble structures obtained in Examples 4 to 6 include ordinary optical images (20×10), polarized images (20×10), and laser confocal microscopy images (50×10);

[0037] Figure 6 This is a real-life decoration appearance picture of the low-fat gel-type Pickering two-phase emulsion foam obtained in Examples 4 to 6;

[0038] Figure 7 The microscopic image of the gel-type Pickering two-phase emulsion foam with coexistence of multi-chamber droplets and bubble structures obtained in Examples 7 to 8;

[0039] Figure 8This is a real-life decoration appearance picture of the low-fat gel-type Pickering two-phase emulsion foam obtained in Examples 7 to 8;

[0040] Fig. 9 This is the appearance of the products obtained in Comparative Example 1 and Comparative Example 2;

[0041] Fig.10 It is a microscopic picture of the products obtained in Comparative Examples 3 and 4;

[0042] Fig.11 It is a microscopic picture of the products obtained in Comparative Examples 5 and 6;

[0043] Fig.12 This is a 3D printing flow chart of Example 11, including model design, 3D printing process and printed sample size determination.

[0044] Fig.13 This is the appearance picture of the 3D printed sample in Example 11. DETAILED DESCRIPTION

[0045] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the embodiments of the specification.

[0046] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0047] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The term "in one embodiment" that appears in different places in this specification does not necessarily refer to the same embodiment, nor does it refer to a separate or selective embodiment that is mutually exclusive with other embodiments.

[0048] The raw materials used in the present invention are all commercially available unless otherwise specified.

[0049] The performance of the material prepared in the embodiment of the present invention was tested as follows:

[0050] Decorating: Fill the obtained foam into a decorating bag and use a 5mm fine-toothed nozzle to decorate to obtain cream flowers.

[0051] Foaming rate: calculated using the following formula

[0052]

[0053] Example 1

[0054] This embodiment provides a method for preparing a low-fat gel-type Pickering two-phase emulsion foam, referring to Figure 1 , specifically:

[0055] (1) preparing an oat protein isolate aqueous solution with a mass concentration of 8%, stirring it thoroughly and refrigerating it in a refrigerator at 0-4° C., hydrating it for 12 hours, adjusting the pH to 7.0, heating the oat protein isolate solution in a 100° C. water bath for 60 minutes, cooling it sufficiently to room temperature, adding 2 U / g of transglutaminase and performing enzyme crosslinking in a 40° C. water bath for 2 hours to obtain an oat protein isolate hydrogel, shearing it for preliminary crushing, and treating it in a high-pressure homogenizer at 60 MPa for 5 minutes to obtain an oat protein gel particle aqueous solution with a mass concentration of 1 wt%;

[0056] (2) 30 g of soybean oil was added to 20 g of the oat protein gel particle solution obtained in step (1), and shear emulsified at 10,000 rpm for 2 min to obtain an initial O / W emulsion.

[0057] (3) Take 50 g of anhydrous milk fat and heat it to 60°C to obtain a clear and transparent mixed oil solution, place it in an ice bath for 10 minutes to partially crystallize, add the O / W type emulsion to the anhydrous milk fat oil phase, shear emulsify at 3000 rpm for 5 minutes, and continue to stand and cool in an ice bath for 1 hour to obtain a gel-type O / W / O two-phase emulsion, in which the water phase accounts for 20% and the oil phase accounts for 80%.

[0058] (4) After storing the gel-type O / W / O two-phase emulsion obtained in step (2) at 20° C. for 24 hours, the emulsion is whipped and aerated at 3000 rpm for 8 minutes at room temperature to obtain a low-fat gel-type Pickering two-phase emulsion foam with coexistence of multi-chamber droplets and bubble structures.

[0059] Example 2

[0060] The difference between this embodiment and Example 1 is that the masses of soybean oil, oat protein gel particle solution and anhydrous milk fat are adjusted to 20g, 40g and 40g respectively (i.e., the water phase of the gel-type O / W / O two-phase emulsion accounts for 40% and the oil phase accounts for 60%), the whipping time is 5 minutes, and the rest of the preparation process is the same as in Example 1 to obtain a two-phase emulsion foam.

[0061] Example 3

[0062] The difference between this embodiment and embodiment 1 is that the masses of soybean oil, oat protein gel particle solution and anhydrous milk fat are adjusted to 10g, 60g and 30g respectively, the whipping time is 3min, and the rest of the preparation process is the same as that of embodiment 1 to obtain a two-phase emulsion foam.

[0063] The low-fat gel-type Pickering two-phase emulsion foam based on anhydrous milk fat obtained in Examples 1 to 3 was tested, and the test results are as follows:

[0064] Figure 2 These are microscopic images of the high-oil-content O1 / W / O2 type two-phase fat emulsion colloid of Examples 1 to 3, wherein (A) is a polarized image, (B) is a normal optical image, and (C) is a laser confocal microscopic image.

[0065] After whipping and aeration, bubbles can be successfully introduced into the gel-type two-phase emulsion. It can be clearly seen that multiple structural units coexist stably in the system, including multi-chamber structured emulsion droplets (water droplets containing densely visible small oil droplets) and bubbles. In the PLM image, the bubbles are evenly distributed, and there are bright layers around all bubbles and droplets, indicating that the crystalline particles formed by high melting point fat adsorbed on the oil-in-gas and oil-in-water surfaces play a good stabilizing role, effectively hindering the relaxation of the emulsion droplet and bubble shape, that is, Pickering-type interface stability. Moreover, the crystal gelation network in the continuous oil phase contributes to the stability of foam and emulsion. Fat crystals can stabilize the oil-water interface and oil-gas interface of the system at the same time, and during the whipping process, the remaining fat crystals in the continuous phase move to the oil-gas interface, while the crystal layer adsorbed on the oil-water interface is not affected. The gel-type two-phase emulsion foam system can be called a "Pickering stabilized" system, in which the water-in-oil interface is stabilized by protein gel particles, and the oil-in-water interface and oil-in-gas interface are stabilized by fat crystals. As the water content increases, the distribution of water droplets becomes more concentrated, and the bubbles are densely distributed in the remaining space of the bulk phase.

[0066] Figure 3 The figures are respectively the decoration pictures of the products in Example 1, Example 2 and Example 3. It can be seen that the obtained gel two-phase emulsion foam system has good decoration plasticity and the extrusion process is smooth. They all have smooth surfaces, are clean light yellow, have soft and delicate textures, and have ideal molding properties. In addition, due to the reduction of bubbles, the increase in water content causes the edges to become clearer and cannot provide good softness.

[0067] The foam prepared in the above embodiment was tested for foaming rate, and the comparison results with those in embodiment 1 are shown in Table 1.

[0068] Table 1

[0069] Example 1 Example 2 Example 3 Foaming rate 105％ 82％ 37％

[0070] It can be seen that the low-fat gel-type Pickering two-phase emulsion foam prepared by the present invention exhibits good whipping and aeration properties without adding any synthetic additives. The foaming rates in Example 1, Example 2 and Example 3 reach 105%, 82% and 37%, respectively. When the water content in the gel two-phase emulsion increases from 20% to 60% in Example 3, the foaming rate of the gel-type two-phase emulsion foam decreases significantly. The main reason is that the increase in the droplet filling volume density in the two-phase emulsion leads to a decrease in the residual space of the continuous phase, and the increase in viscosity inhibits the introduction of bubbles.

[0071] The gel-type Pickering two-phase emulsion foam obtained in Example 2 was subjected to a stable reversible behavior test. Figure 4 The results of the foaming rate changes after different thermal cycles are shown in Table 2.

[0072] Table 2

[0073] One thermal cycle Secondary heat cycle Three thermal cycles Foaming rate 91％ 86％ 80％

[0074] It can be found that at 28°C, there is obvious oil separation under the foam, and at 33°C, the foam collapses and disappears in a large area. At 70°C, due to the melting of the high-melting-point fat crystals in the outer oil phase, the foam is completely unstable and collapses, showing a transparent yellow liquid oil. The remaining white sample in the system was taken for microscopic observation, and it was found that although the outer layer was completely melted, the primary oil-water emulsion in the gel state remained stable, and the size and distribution of the droplets did not change significantly. Therefore, the protein gel particles can form a solid interface to fully resist heat treatment. After this initial O / W emulsion was cooled in an ice bath, it only needed to be homogenized once to form a gel-like two-phase emulsion with a multi-chamber droplet structure again. Furthermore, after whipping again, a gel-type two-phase emulsion foam with a fine texture, uniformly distributed bubbles, and coexistence of multi-chamber droplets and bubble structures was successfully prepared. In addition, after different heating-homogenization-aeration cycles, the foaming rate changes as shown in Table 2, and it is found that the foaming rate has no obvious change, thus, it proves that the thermal reversibility of melting and crystallization of fat crystals endows the stable gel-type two-phase emulsion foam system with excellent thermal reversibility.

[0075] Example 4

[0076] The difference between this embodiment and embodiment 1 is that the vegetable protein is adjusted to bean protein isolate, and a low-fat gel-type Pickering two-phase emulsion foam based on coconut oil is prepared. Specifically:

[0077] (1) preparing a 10% aqueous solution of isolated broad bean protein, stirring it thoroughly and refrigerating it in a refrigerator, hydrating it for 12 hours, adjusting the pH to 7.0, heating the isolated broad bean protein solution in a 90° C. water bath for 60 minutes, cooling it sufficiently to room temperature, adding 3 U / g of transglutaminase and performing enzyme crosslinking in a 40° C. water bath for 3 hours to obtain isolated broad bean protein hydrogel, shearing it for preliminary crushing, and treating it in a high-pressure homogenizer at 60 MPa for 5 minutes to obtain an oat protein gel particle solution with a mass concentration of 2 wt%;

[0078] (2) 20 g of peanut oil was added to 30 g of the broad bean protein gel particle solution obtained in step (1), and shear emulsified at 10,000 rpm for 2 min to obtain an initial O / W emulsion.

[0079] (3) 50 g of coconut oil was heated at 60° C. to obtain a clear and transparent mixed oil solution, which was placed in an ice bath for 20 min to partially crystallize. The O / W emulsion was added to the palm oil phase, sheared and emulsified at 4000 rpm for 5 min, and then allowed to stand and cool in an ice bath for 1 h to obtain a gel-type O / W / O two-phase emulsion, in which the water phase accounted for 30% and the oil phase accounted for 70%.

[0080] (4) The gel-type O / W / O two-phase emulsion obtained in step (3) is whipped and aerated at 3000 rpm for 10 minutes at room temperature to obtain a low-fat gel-type Pickering two-phase emulsion foam with coexistence of multi-chamber droplets and bubble structures.

[0081] Example 5

[0082] The difference between this embodiment and embodiment 4 is that the masses of peanut oil, broad bean protein gel particle solution and coconut oil are adjusted to 30 g, 30 g and 40 g respectively, and the rest of the preparation process is the same as that of embodiment 4 to obtain a gel-type Pickering two-phase emulsion foam.

[0083] Example 6

[0084] The difference between this embodiment and embodiment 4 is that the masses of peanut oil, broad bean protein gel particle solution and coconut oil are adjusted to 15 g, 60 g and 25 g respectively, and the rest of the preparation process is the same as that of embodiment 4 to obtain a gel-type Pickering two-phase emulsion foam.

[0085] The low-fat gel-type Pickering two-phase emulsion foam based on coconut oil obtained in Examples 4 to 6 was tested, and the test results are as follows:

[0086] Figure 5The microscopic images of the samples of Examples 4 to 6, wherein (A) is a polarized image and (B) is a normal optical image. It can be seen that the multi-chamber structure droplets and dense bubbles stably coexist in the gel-type Pickering two-phase emulsion foam stabilized by coconut oil, so the coconut oil crystals can successfully stabilize the oil-in-water interface and the oil-in-air interface, achieving the Pickering stabilization of the multi-interface of the gel-type two-phase emulsion foam system.

[0087] Figure 6 The decoration appearance pictures of the samples obtained in Examples 4 to 6 are shown. It can be seen that the foam of the gel-type Pickering two-phase emulsion stabilized by coconut oil is milky white, soft and delicate in texture, and similar in shape to whipped cream.

[0088] The foam prepared in the above embodiment was tested for foaming rate, and the comparison results with those in embodiment 1 are shown in Table 3.

[0089] Table 3

[0090] Example 1 Example 2 Example 3 Foaming rate 98％ 76％ 35％

[0091] It can be seen that the foaming rates of the samples obtained in Examples 4 to 6 are 98%, 76%, and 35%, respectively. The higher the mass ratio of the high melting point fat in the external phase in Examples 1, 2, and 4, the higher the foaming rate. The reduction in the content of the high melting point fat in the external oil phase will lead to a reduction in the crystal particles used to stabilize the interface, thereby reducing the foaming rate.

[0092] Example 7

[0093] The difference between this embodiment and embodiment 1 is that the vegetable protein potato protein isolate is adjusted to prepare a low-fat gel-type Pickering two-phase emulsion foam based on palm stearin. Specifically:

[0094] (1) preparing a potato protein isolate aqueous solution with a mass concentration of 12%, stirring it thoroughly and refrigerating it in a refrigerator, hydrating it for 12 hours, adjusting the pH to 7.0, heating the potato protein isolate solution in a 90° C. water bath for 45 minutes, placing it in a refrigerator at 20° C. for 24 hours to obtain a potato protein isolate hydrogel, shearing it for preliminary crushing, and treating it with a high-pressure homogenizer at 60 MPa for 5 minutes to obtain a potato protein gel particle solution with a mass concentration of 2 wt%;

[0095] (2) 20 g of rapeseed oil was added to 40 g of the gel particle solution obtained in step (1), and shear emulsified at 10,000 rpm for 2 min to obtain an initial O / W emulsion.

[0096] (3) 12 g of palm stearin and 28 g of rapeseed oil were mixed, heated at 60° C. to obtain a clear and transparent mixed oil solution, placed in an ice bath for 15 min for partial crystallization, the O / W type emulsion was added to the mixed oil phase, shear emulsified at 4000 rpm for 5 min, and continued to stand and cool in an ice bath for 1 h to obtain a gel-type O / W / O two-phase emulsion (wherein the mass ratio of palm stearin to the total system was 12%);

[0097] (4) The gel-type O / W / O two-phase emulsion obtained in step (3) is whipped and aerated at 3500 rpm for 8 minutes at room temperature to obtain a low-fat gel-type Pickering two-phase emulsion foam with coexistence of multi-chamber droplets and bubble structures.

[0098] Example 8

[0099] The difference between this embodiment and embodiment 7 is that step (3) is adjusted to mixing 20 g of palm stearin with 20 g of rapeseed oil (i.e., the mass fraction of palm stearin in the gel-type O / W / O two-phase emulsion is 20%), and the rest of the preparation process is the same as that of embodiment 7 to obtain a gel-type Pickering two-phase emulsion foam.

[0100] The products obtained in Example 7 and Example 8 were subjected to performance tests, and the test results are as follows:

[0101] Figure 7 The microscopic images of the palm stearin-based gel-type Pickering two-phase emulsion foam obtained in Examples 7-8, (A) is a normal optical image, (B) is a polarized image, and (C) is a laser confocal micrograph. It can be seen from the figure that at 12% and 20% palm stearin content, a gel-type Pickering two-phase emulsion foam with a multi-chamber droplet structure and coexistence of bubbles can be formed. At this time, the crystalline particle adsorption layer of the high-melting-point palm stearin still acts as a good stabilizer for oil-in-gas and oil-in-water, and the water-oil interface of the colostrum is coated with potato protein isolate gel particles. As the palm stearin content increases from 12% to 20%, the water droplets wrapped inside the multi-chamber droplets are more and smaller, the encapsulation effect is excellent, and the bubble distribution is more uniform and denser.

[0102] Figure 8 The decoration pictures of the products obtained in Example 7 and Example 8 show that the gel-type Pickering two-phase emulsion foam with different palm stearin contents has good plasticity and decoration properties, which greatly expands its practical application.

[0103] The test results of the foaming rate of Example 7 and Example 8 are shown in Table 4.

[0104] Table 4

[0105] Example 7 Example 8 Foaming rate 77％ 112％

[0106] It can be seen that with the increase of palm stearin content, the foaming rate of the obtained foam system increases significantly.

[0107] Comparative Example 1

[0108] The difference between this comparative example and Example 1 is that O / W colostrum is added to a mixture of 20 g of anhydrous milk fat and 20 g of soybean oil, and the rest of the preparation process is the same as that of Example 1 to prepare a two-phase emulsion foam.

[0109] Fig. 9 As for the appearance of the obtained product, it is found that when the melting point of the high-melting-point oil used is not too high, if its content in the system is low, it cannot be successfully whipped into an emulsion foam with good shaping.

[0110] Comparative Example 2

[0111] The step (2) in Example 7 was changed to mixing 35 g of palm stearin with 5 g of rapeseed oil, and the remaining steps were kept the same as in Example 7 to obtain a gel-type O / W / O two-phase emulsion, in which the mass ratio of palm stearin to the total system was 35%.

[0112] Fig. 9 This is the appearance of the obtained product. It can be seen that when the high melting point oil palm stearin used has a high melting point (melting point 45°C), its content is too high will cause the gel-type O / W / O two-phase emulsion to be too hard, difficult to whip, and the foam texture is rough, resulting in reduced quality.

[0113] Comparative Example 3

[0114] The difference between this comparative example and Example 1 is that step (4) in Example 1 is changed to: the obtained gel-type O / W / O two-phase emulsion is whipped and aerated at 3000 rpm by a whipper at room temperature, and the rest of the preparation process is the same as that in Example 1.

[0115] Microscopic examination revealed that Fig.10 ), in this comparative example, if the obtained gel-type O / W / O two-phase emulsion is not stored for a period of time, and is directly whipped at room temperature, the crystals formed by the high-melting-point oil will not grow well, and the small crystals will not be able to stabilize the oil-gas interface well during whipping, and the bubbles filled in will not be well stabilized, resulting in a very low foaming rate of the gel-type O / W / O two-phase emulsion foam.

[0116] Comparative Example 4

[0117] The step (3) in Example 3 was changed to whipping at 3000 rpm for 8 min with a whipper, and the other steps remained the same to obtain a low-fat gel-type Pickering two-phase emulsion foam with coexistence of multi-chamber droplets and bubble structures.

[0118] Microscopic examination revealed that Fig.10 ), when the water content in the system is high, the whipping and aeration time is too long, which will lead to the destruction of the two-phase structure, the disappearance of the multi-chamber emulsion droplet structure, and the inability to form a foam system.

[0119] Example 9

[0120] This embodiment provides an application of a low-fat gel-type Pickering two-phase emulsion foam, specifically:

[0121] 1 mg / mL of hydrophilic nutrient (EGCG) and hydrophobic nutrient (lycopene) were respectively encapsulated into the aqueous solution of plant protein particles and liquid vegetable oil of Examples 1 to 8, and then a low-fat gel-type Pickering two-phase emulsion foam was prepared. The remaining preparation processes were the same as those of the corresponding examples, and a low-fat gel-type Pickering two-phase emulsion foam co-encapsulating hydrophobic lycopene and hydrophilic EGCG nutrient was obtained, specifically:

[0122] 1 mg / mL of EGCG was added to the aqueous solution of plant protein gel particles, and the EGCG dispersion was obtained after sufficient stirring; 1 mg / mL of lycopene was added to liquid vegetable oil, and the lycopene oil solution was obtained after ultrasonic stirring.

[0123] The test results of nutrient embedding rate in the system obtained in this example are shown in Table 5.

[0124] Table 5

[0125] Foam system Lycopene embedding rate EGCG embedding rate Example 1 85.3％ 92.5％ Example 2 87.4％ 90.3％ Example 3 89.8％ 85.9％ Example 4 87.5％ 91.6％ Example 5 93.7％ 94.3％ Example 6 94.1％ 90.1％ Example 7 94.6％ 96.4％ Example 8 92.0％ 93.5％

[0126] It can be seen that the nutrient co-loaded gel-type Pickering two-phase emulsion foam constructed with oat protein and anhydrous milk fat can achieve high-efficiency co-loading of hydrophilic and hydrophobic nutrients. The loading rates of the two nutrients are both above 85% under different water content conditions, and it can be used as an excellent encapsulation and nutritional fortification functional fat system.

[0127] The lycopene and EGCG co-loaded gel-type Pickering two-phase emulsion foam constructed with coconut oil and broad bean protein isolate can achieve high-efficiency co-loading of the two nutrients, and the loading rates of the two nutrients are both above 85%.

[0128] The lycopene and EGCG co-loaded gel-type Pickering two-phase emulsion foam constructed with palm stearin and potato protein isolate can achieve high-efficiency co-loading of the two nutrients, and the loading rates of the two nutrients are all above 85% at different palm stearin contents.

[0129] Comparative Example 5

[0130] This comparative example is based on the foam system of Example 1, and the concentration of EGCG is adjusted to 5 mg / mL and the concentration of lycopene is adjusted to 10 mg / mL. Specifically:

[0131] 5 mg / mL EGCG was weighed and added to the aqueous solution of plant protein gel particles, and the EGCG dispersion was obtained after sufficient stirring; 10 mg / mL lycopene was weighed and added to liquid vegetable oil, and the lycopene oil solution was obtained after ultrasonic stirring; the rest of the preparation process was the same as that in Example 1.

[0132] Fig.11 The microscopic image of the obtained product shows that when the lycopene content is too high, the amount of multi-chamber emulsion droplets formed in the system will decrease, the hardness of the gel system will be greatly reduced, and the whipping and aeration rate will be reduced. Therefore, only when a certain amount of lycopene is present can a gel-type Pickering two-phase emulsion foam with good structure and characteristics and coexistence of nutrient co-encapsulated low-fat multi-chamber emulsion droplets and bubble structure be formed.

[0133] Comparative Example 6

[0134] This comparative example is based on the foam system of Example 1, and the concentration of EGCG is adjusted to 10 mg / mL and the concentration of lycopene is adjusted to 5 mg / mL. Specifically:

[0135] 10 mg / mL EGCG was weighed and added to the aqueous solution of plant protein gel particles, and the EGCG dispersion was obtained after sufficient stirring; 5 mg / mL lycopene was weighed and added to liquid vegetable oil, and the lycopene oil solution was obtained after ultrasonic stirring; the rest of the preparation process was the same as that in Example 1.

[0136] Fig.11 This is a microscopic picture of the obtained product. It was found that when the EGCG content was too high, due to its interaction with the plant protein particles, its emulsification ability was also reduced, which was not conducive to the formation of a multi-chamber structure in the system, and thus led to a decrease in the quality of the gel-type Pickering two-phase emulsion foam system.

[0137] Example 10

[0138] This embodiment provides an application of a low-fat gel-type Pickering two-phase emulsion foam co-loaded with lycopene and EGCG in 3D printing, referring to Fig.12 , specifically:

[0139] (1) The gel-type Pickering two-phase emulsion foam co-loaded with lycopene and EGCG obtained in Examples 1 to 3 and 7 to 8 was loaded into a 3D printing syringe with a volume capacity of 60 mL, ensuring that the loading was uniform and without gaps, and a 3D printing gun tip with a diameter of 0.60 mm was selected for installation.

[0140] (2) After the model was designed using 3Ds Max modeling software, various parameters in the 3D printing process were set using Repetier-Host software; the specific parameters of the printer were as follows: the horizontal movement speed of the printer base head was 1800 mm / min, the Z-direction movement speed was 100 mm / min, the height was 0.6 mm, the initial layer height was 0.84 mm, the filling density was 40%, the filling mode was straight line, the printing rate was 20 mm / s, the non-printing movement rate was 30 mm / s, the filling rate was 20 mm / s, the bottom and top layer rates were 20 mm / s, the shell rate was 30 mm / s, and the inner wall rate was 30 mm / s. After the parameters were set, a three-dimensional slice model was generated through slicing processing, and the slice printing code was generated in Gcode format and imported into the 3D printer.

[0141] (3) Install the material barrel onto the dual-channel 3D food printer, set the printing preheating temperature to 25°C, set the platform height to -1.6 mm, adjust the feed to ensure smooth discharge, set the printer to zero the X, Y, and Z axes, select the imported printing model for printing, and obtain a 3D printed sample with a certain self-supporting property.

[0142] Fig.13 This is the appearance of the 3D printed sample in this embodiment. The printing accuracy and nutrient retention rate of the obtained 3D printed sample are shown in Table 7.

[0143] Table 7

[0144] Foam system Printing accuracy Lycopene retention rate EGCG retention rate Example 1 Anhydrous milk fat (20% water content) 60.5％ 93.5％ 98.5％ Example 2 Anhydrous milk fat (40% water content) 92.7％ 95.7％ 98.7％ Example 3 Anhydrous milk fat (60% water content) 95.3％ 92.2％ 93.6％ Example 7 Palm stearin (12%) 95.7％ 97.2％ 95.3％ Example 8 Palm stearin (20%) 97.8％ 95.5％ 93.1％

[0145] It can be seen that the low-fat gel-type Pickering two-phase emulsion foam with coexistence of multi-chamber emulsion droplets and bubble structures loaded with lycopene and EGCG can successfully realize model 3D printing. By changing the characteristics of the high-melting-point vegetable oils used, the content of high-melting-point oils or adjusting the oil-water content, the printing accuracy can be effectively regulated. In addition, the low-fat gel-type Pickering two-phase emulsion foam loaded with lycopene and EGCG has both nutrients well preserved after 3D printing, and the printing process will not damage the structure and cause nutrient loss, thus realizing the personalized nutritional needs of 3D printed functional fat-based products.

[0146] In summary, the gel-type Pickering two-phase emulsion foam prepared by the present invention has coexistence of multi-chamber droplets and bubble structures, does not contain any synthetic emulsifiers, does not contain trans fatty acids, and multiple interfaces are Pickering stabilized. It has a soft and delicate texture and good plasticity. It can be further used for the co-loading of hydrophilic and hydrophobic nutrients, and realizes 3D printing of nutritional whipping and aeration systems, thereby realizing diversified application scenarios.

[0147] From the perspective of health, the present invention develops a novel surfactant-free, multi-chamber droplet and bubble coexisting low-fat Pickering two-phase emulsion gel foam system, wherein the protein gel particles stabilize the water-in-oil interface, and the fat crystals effectively stabilize the oil-in-water and oil-in-gas interfaces. The presence of different structural units and phases allows for better and more precise performance control of the product, and the entire product preparation process does not require a low-temperature environment, and can be stored and whipped and aerated at room temperature.

[0148] The Pickering two-phase emulsion gel foam prepared by the invention has a stable structure, a high whipping rate, excellent plasticity, decorating properties, and thermal reversibility, does not contain trans fatty acids, has properties close to those of fat, can be used as a good low-fat healthy fat substitute, and has good application potential in the development and manufacture of zero-trans, low-saturated fatty acid non-dairy cream products.

[0149] The present invention uses the prepared low-fat Pickering two-phase emulsion gel foam in which multi-chamber droplets and bubbles coexist to jointly load the hydrophobic nutrient lycopene and the hydrophilic nutrient EGCG, thereby achieving high-efficiency co-loading of EGCG and lycopene and effectively enhancing their nutritional functions.

[0150] The present invention 3D prints a low-fat Pickering two-phase emulsion gel foam co-loaded with nutrients. The adjustability of the ink allows the tolerance of the 3D printed product to the extrusion process to be enhanced by adjusting the fat type and content, thereby achieving a high retention rate of EGCG and lycopene during the printing process, providing greater space for personalized nutrition of future 3D printed functional fat-based products.

[0151] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A method for preparing a low-fat gel-type Pickering two-phase emulsion foam, characterized in that: include, Adding liquid vegetable oil to the aqueous solution of vegetable protein gel particles, shearing and emulsifying, to obtain an O / W type primary emulsion; The high melting point fat and liquid vegetable oil are mixed, heated to melt, and partially crystallized in an ice bath, the obtained O / W type primary emulsion is added thereto, sheared and homogenized, and then continued to stand and cool in an ice bath to obtain a gel type O / W / O two-phase emulsion; The gel-type O / W / O two-phase emulsion is stored for a period of time and then whipped at room temperature to obtain a low-fat gel-type Pickering two-phase emulsion foam with coexistence of multi-chamber emulsion droplets and bubble structures; Among them, the addition amount of the liquid vegetable oil is 5% to 35% of the O / W / O two-phase emulsion, the addition amount of the plant protein gel particle aqueous solution is 10% to 70% of the O / W / O two-phase emulsion, the mass ratio of the high melting point oil and liquid vegetable oil after mixing in the O / W / O two-phase emulsion is 25% to 85%, and the concentration of the plant protein gel particle aqueous solution is 0.5% to 3%.

2. The method for preparing the low-fat gel-type Pickering two-phase emulsion foam according to claim 1, characterized in that: The liquid vegetable oil includes one of soybean oil, rapeseed oil, peanut oil, sunflower seed oil, rice bran oil, corn oil, linseed oil, olive oil, wheat germ oil, cottonseed oil, almond oil, tea seed oil, and sesame oil; the high melting point oil is one or more of milk fat, palm oil, palm kernel oil, palm stearin, coconut oil, cocoa butter, shea butter, balsam pear resin, mango kernel oil, and ice grass fat.

3. The method for preparing the low-fat gel-type Pickering two-phase emulsion foam according to claim 1, characterized in that: The preparation method of the plant protein gel particles, include, A 5% to 20% mass concentration of vegetable protein aqueous solution is fully hydrated at 0 to 4°C for 12 to 24 hours, the pH is adjusted to 7.0 to 7.5, and then subjected to heat denaturation and enzyme cross-linking treatment to obtain a vegetable protein gel, which is then crushed and homogenized to obtain nano-scale vegetable protein gel particles; The plant protein includes one of soy protein isolate, peanut protein isolate, pea protein isolate, mung bean protein isolate, oat protein isolate, quinoa protein isolate, broad bean protein isolate, and potato protein isolate; The heat denaturation is performed by heating at 80-100° C. for 0.5-4 h; the enzyme cross-linking is performed by using 2-5 U / g of transglutaminase at 40-45° C. for 2-5 h.

4. The method for preparing the low-fat gel-type Pickering two-phase emulsion foam according to claim 1, characterized in that: The heating and melting conditions are heating at 50-80° C. for 30-60 minutes; and the partial crystallization time is 20-60 minutes.

5. The method for preparing the low-fat gel-type Pickering two-phase emulsion foam according to claim 1, characterized in that: The shear emulsification conditions of the O / W colostrum are 8000-12000 rpm for 2-5 min; the shear emulsification conditions of the gel-type O / W / O two-phase emulsion are 3000-5000 rpm for 2-8 min; and the cooling time is 30-90 min.

6. The method for preparing the low-fat gel-type Pickering two-phase emulsion foam according to claim 1, characterized in that: The storage condition is 15-25° C. for 12-24 hours, and the whipping is at 2000-4000 rpm for 4-10 minutes.

7. The low-fat gel-type Pickering two-phase emulsion foam prepared by the method according to claims 1 to 6, characterized in that: The foam multi-chamber emulsion droplets and bubble structures coexist.

8. Use of the low-fat gel-type Pickering two-phase emulsion foam according to claim 7 in co-loading nutrients, characterized in that: include, The hydrophilic nutrients and the hydrophobic nutrients are respectively added into the aqueous solution of the plant protein particles and the liquid edible vegetable oil, and after being evenly mixed, a low-fat gel-type Pickering two-phase emulsion foam is prepared.

9. Use of the low-fat gel-type Pickering two-phase emulsion foam according to claim 8 in co-loading nutrients, characterized in that: The hydrophilic nutrient includes EGCG, the hydrophobic nutrient includes lycopene, and the added amount of the nutrient is 1 to 5 mg / mL.

10. Use of the low-fat gel-type Pickering two-phase emulsion foam as claimed in claim 7 in 3D printing.

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