Emulsion based on synergistic stabilization mechanism of polysaccharide molecules and polysaccharide microgels, and preparation method and application thereof

Abstract

The application provides a preparation method of an emulsion based on a polysaccharide molecule and polysaccharide microgel synergistic stabilization mechanism, comprising the following steps: first, using a polysaccharide with a spiral structure as raw material, a polysaccharide microgel suspension is prepared; second, the polysaccharide microgel suspension is mixed with an oil phase, and a first mixture is formed by high-speed shearing; third, galactomannan is added to water, dissolved by heating, and a second mixture is obtained; finally, the first mixture is added to the second mixture in a certain proportion, and mixed to obtain an emulsion based on the polysaccharide molecule and polysaccharide microgel synergistic stabilization mechanism. The preparation method has the advantages of low cost and simple preparation process, and is suitable for industrial production; the preparation method can also significantly improve the stability of the polysaccharide microgel emulsion, improve the freeze-thaw cycle performance of the emulsion, and the prepared emulsion system can be used for liposoluble active ingredient delivery, and has a wide application prospect in the design and development of low-fat foods.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of emulsion preparation, and specifically relates to an emulsion based on a synergistic stabilization mechanism of polysaccharide molecules and polysaccharide microgels and a preparation method thereof, and also relates to application of the emulsion in food engineering. BACKGROUND

[0002] An emulsion is a system formed by two thermodynamically incompatible phases, which is stabilized by reducing the surface tension with emulsifiers so that one phase is stably dispersed in the other phase. Through ingenious interface structure design, not only the micro-stability of individual emulsion droplets can be achieved, but also the interaction between emulsion droplets can be regulated, so that the emulsion exhibits different macro-stability and rheological properties. In the food industry, emulsion systems not only can provide ideal appearance, texture and taste characteristics for products, but also have broad application prospects in the preparation of functional and healthy foods, such as low-fat foods, which reduce oil intake while retaining oil flavor; functional active ingredient delivery, which loads fat-soluble ingredients in the inner phase of oil-in-water.

[0003] In actual production and life, in order to ensure the shelf life of food and drugs, cold chain transportation and low-temperature storage in the environment are usually adopted. However, the instability of the environmental temperature can seriously affect the quality of the product, and thus affect the sales of the product. For emulsion products, the freeze-thaw process is particularly critical, because the growth of ice crystals can destroy the stability of the oil-water interface film, resulting in oil-water separation after thawing. Therefore, improving the freeze-thaw stability of emulsion products is an important way to ensure the shelf life and stability of the products.

[0004] Chinese patent CN113397122B discloses a method for preparing freeze-thaw resistant Pickering emulsion using desalted salted egg white gel particles, in which egg white gel particles are mixed with sodium alginate solution as emulsifiers to prepare freeze-thaw resistant Pickering emulsion. Chinese patent CN116709932A discloses enzyme-crosslinked sugar beet pectin microgel particles for use in food, and their use in the preparation of oil-in-water emulsions. Chinese patent CN115403833A discloses a non-dissolved agar powder emulsifier, its preparation method and use, which significantly improves the emulsifying activity of agar powder through processes such as agar dissolution, esterification modification, cooling gelation, dehydration and high-speed pulverization.

[0005] Although the emulsions provided by the above-mentioned patents improve the stability of the products, they have the problems of complicated process and dependence on complex technical means such as chemical modification, which is not conducive to the production and application of the food industry. The protein raw material has the risk of allergen and is relatively high in cost, and the development of natural polysaccharide-based emulsion is an urgent demand of the market. In addition, the strategy of preparing polysaccharide microgel by enzyme cross-linking involved in the above-mentioned patents requires the raw material to have a characteristic cross-linking site such as ferulic acid, and is not applicable to other natural polysaccharides which are low in price and lack oil-water amphiphilicity. Therefore, establishing a new emulsification strategy based on non-emulsifying polysaccharides can not only enrich the types of natural emulsifiers, but also effectively mobilize the abundant and inexpensive natural polysaccharide resources.

[0006] Therefore, there is an urgent need for a method for improving the emulsification activity of natural polysaccharides, providing an emulsion prepared only with natural polysaccharides as emulsifiers, which can significantly improve the freeze-thaw cycle stability of the emulsion while reducing the cost of emulsion preparation and simplifying the preparation process, and it is a technical problem to be solved. SUMMARY

[0007] One of the purposes of the present application is to provide a preparation method of an emulsion based on the synergistic stabilization mechanism of polysaccharide molecules and polysaccharide microgels, which has excellent freeze-thaw cycle stability.

[0008] The second purpose of the present application is to provide an emulsion based on the synergistic stabilization mechanism of polysaccharide molecules and polysaccharide microgels, which has excellent freeze-thaw cycle stability.

[0009] The third purpose of the present application is to provide an application of an emulsion based on the synergistic stabilization mechanism of polysaccharide molecules and polysaccharide microgels in food engineering.

[0010] The technical solution adopted by one of the purposes of the present application is to provide a preparation method of an emulsion based on the synergistic stabilization mechanism of polysaccharide molecules and polysaccharide microgels, which comprises the following steps:

[0011] S1. Using polysaccharides with a helical structure as raw materials, polysaccharide microgel suspension with a polysaccharide content of 0.2wt.% to 0.5wt.% is prepared;

[0012] S2. The polysaccharide microgel suspension and the oil phase are mixed at a mass ratio of 8:2 to 7:3, and a first mixture is formed by high-speed shearing;

[0013] S3. Galactomannan is added to water and dissolved by heating to obtain a second mixture with a galactomannan content of 0.4wt.% to 1.0wt.%;

[0014] S4. The first mixture is added to the second mixture at a mass ratio of 1:1 to 1:1.5, and a emulsion based on the synergistic stabilization mechanism of polysaccharide molecules and polysaccharide microgels is obtained by mixing.

[0015] The general idea of the preparation method of the emulsion based on the synergistic stabilization mechanism of polysaccharide molecules and polysaccharide microgels provided by the present application is as follows:

[0016] The present application adopts a step-by-step emulsification strategy. First, a suspension containing polysaccharide microgels is prepared using polysaccharides with a helical structure as raw materials. Second, the suspension is mixed with an oil phase using polysaccharide microgels as emulsifiers, and an emulsion stabilized by polysaccharide microgels is formed through high-speed shearing. Finally, the polysaccharide microgel-stabilized emulsion is mixed with galactomannan, a layer of galactomannan molecules is covered on the surface of the emulsion droplets through the specific binding between polysaccharide microgels and galactomannan, a multi-layer interface structure is constructed, and the mechanical strength of the interface layer is enhanced to achieve the goal of improving the stability of the emulsion.

[0017] The present application takes into account that natural polysaccharide molecules lack oil-water amphiphilicity and are difficult to stabilize oil-in-water emulsions. Polysaccharides with a helical structure are first prepared into polysaccharide microgels with oil-water amphiphilicity, and then the polysaccharide microgel suspension is mixed with an oil phase to prepare an emulsion. Through further research, it is found that the adsorption stability of single polysaccharide microgels on the oil-water interface is still not ideal, and desorption easily occurs during freeze-thaw cycles, resulting in unstable emulsions. Therefore, the present application further adds an aqueous solution of galactomannan, utilizes the interaction between polysaccharide microgels and galactomannan molecules to improve the interface structure and mechanical properties, and improves the adsorption stability of polysaccharide microgels on the oil-water interface by means of step-by-step emulsification, thereby improving the freeze-thaw cycle resistance of the emulsion.

[0018] In the above preparation method, in order to ensure that the emulsion has good flow performance and avoid the generation of gel state, the content of polysaccharide in the polysaccharide microgel suspension, the content of oil phase in the first mixture, and the content of galactomannan in the second mixture need to be controlled.

[0019] The present application limits the content of polysaccharide in the polysaccharide microgel suspension to 0.2wt.%~0.5wt.%, ensuring that the sample has good flowability; the polysaccharide microgel suspension is mixed with the oil phase at a mass ratio of 8:2~7:3, the amount of oil phase is controlled to ensure that the emulsion has good stability and flowability, which is conducive to the uniformity of the secondary mixing of the emulsion and the galactomannan solution; the content of galactomannan in the second mixture is controlled to be 0.4wt.%~1.0wt.%, which can reduce the viscosity of galactomannan under the premise of ensuring the dosage of galactomannan, and is conducive to the uniform mixing of the emulsion and galactomannan; finally, by adjusting the ratio of the first mixture and the second mixture to 1:1~1:1.5, the polysaccharide microgels interact with the polysaccharide molecules to improve the adsorption stability on the oil-water interface, and the emulsion is stabilized by adsorption rather than thickening. The emulsion prepared in this way has excellent stability while maintaining good flow performance, greatly expanding the application scenarios of the prepared emulsion.

[0020] Further, in step S1, the polysaccharide with helical structure includes one or more combinations of agar, K-carrageenan, pectin. Preferably, the polysaccharide with helical structure is selected from K-carrageenan.

[0021] Preferably, in step S1, the content of polysaccharide in the polysaccharide microgel suspension is 0.4wt.%-0.5wt.%.

[0022] Further, in step S1, when the polysaccharide with helical structure is selected from K-carrageenan and / or pectin, the preparation method of the polysaccharide microgel suspension includes: dissolving the polysaccharide with helical structure in deionized water, heating and stirring until completely dissolved to obtain a homogeneous solution; under heating conditions, adding a salt solution to the homogeneous solution dropwise, and naturally cooling under continuous shearing conditions to form a polysaccharide microgel suspension.

[0023] Preferably, the salt solution includes one or more combinations of KCl, NaCl, CaCl2 aqueous solution, and the salt concentration in the polysaccharide microgel suspension is 25-100mmol / L.

[0024] Preferably, the heating temperature is 70-80℃, the heating time is 10-15min, and the stirring speed is 300-1000rpm; the carrageenan concentration in the homogeneous solution is 1.5wt.%-2.5wt.%.

[0025] Further, when the polysaccharide with helical structure is agar, the preparation method of the polysaccharide microgel suspension includes: dissolving agar in deionized water, heating and stirring until completely dissolved to obtain a homogeneous solution, and naturally cooling under continuous shearing conditions to form an agar microgel suspension.

[0026] Preferably, the heating temperature is 70-80℃, the heating time is 10-15min, and the stirring speed is 300-1000rpm.

[0027] Further, in step S1, the particle size of the polysaccharide microgel in the polysaccharide microgel suspension is 1-10μm. Preferably, the particle size of the polysaccharide microgel is 1-5μm. In the present application, the particle size of the polysaccharide microgel is controlled in a smaller range, which can better improve the adsorption effect on the oil-water interface when used as an emulsifier.

[0028] Further, in step S2, the oil phase includes one or more combinations of soybean oil, peanut oil, corn oil, sunflower seed oil.

[0029] Further, in step S2, the rotation speed of high-speed shearing is 8000-12000rpm, and the time is 2-3min.

[0030] Further, in step S3, the galactomannan includes a combination of one or more of fenugreek gum, guar gum, tara gum, locust bean gum. Galactomannan (GMs) is a general term for a class of polysaccharides, the molecular structure is characterized by: heteropolysaccharide composed of mannose and galactose, in which mannose is connected by (1-4) bond to form a main chain, and one galactose branch is connected by (1-6) bond every few mannose residues. Fenugreek gum, guar gum, tara gum and locust bean gum (LBG) are all GMs, the difference lies in the ratio of galactose to mannose (G / M) in the molecule.

[0031] Preferably, in step S3, the heating temperature is 70-90℃, the heating time is 20-40min, and the heating dissolution is carried out under stirring condition, and the stirring speed is 300-500rpm.

[0032] Further, in step S4, the stirring speed of the mixing is 500-1000rpm, and the time is 5-10min.

[0033] The technical scheme for achieving the second purpose of the present application is to provide an emulsion based on the synergistic stabilization mechanism of polysaccharide molecules and polysaccharide microgels, which is prepared by the preparation method according to the first purpose of the present application.

[0034] In the emulsion provided by the present application, the polysaccharide with helical structure in the form of gel particles is combined with the galactomannan in the form of molecules, and a step-by-step emulsification strategy is adopted to combine polysaccharides of different forms and exert synergistic stabilization mechanism, improve the interface structure and mechanical properties, and realize the improvement of the freeze-thaw cycle performance of the emulsion.

[0035] The technical scheme for achieving the third purpose of the present application is to provide an application of the emulsion based on the synergistic stabilization mechanism of polysaccharide molecules and polysaccharide microgels according to the second purpose of the present application in food engineering.

[0036] Preferably, the emulsion provided by the present application can be used as a carrier for various active substances, and can be used for oral delivery of nutritional fortifiers of hydrophobic substances such as polyunsaturated fatty acids, curcumin and carotene. The emulsion provided by the present application also has the advantage of low oil content, and can be widely used in the development of low-fat foods.

[0037] Compared with the prior art, the emulsion provided by the present application has the following advantages:

[0038] (1) The application provides a preparation method of an emulsion based on a synergistic stabilization mechanism of polysaccharide molecules and polysaccharide microgels, which adopts a step-by-step emulsification strategy to mix polysaccharide microgel-stabilized emulsion and polysaccharide molecule solution for the second time. For the first time, the interaction mechanism between polysaccharide molecules and polysaccharide microgels is used to strengthen the oil-water interface layer formed by polysaccharide microgels, and the stability of the polysaccharide microgel emulsion is significantly improved.

[0039] (2) The emulsion based on the synergistic stabilization mechanism of polysaccharide molecules and polysaccharide microgels prepared by the application has good freeze-thaw stability, and effectively improves the commercial value of the product. In addition, the emulsion has the advantages of simple and efficient production process, low production cost, environmental safety and the like, and is suitable for industrial production.

[0040] (3) The emulsion based on the synergistic stabilization mechanism of polysaccharide molecules and polysaccharide microgels prepared by the application not only can be used as an embedding carrier for many active substances, but also can be widely used in the development of low-fat foods. In addition, the emulsion has good fluidity and freeze-thaw stability, which is beneficial to maintaining the physical stability in the process of cold chain transportation, storage and sales, and has a wide popularization and application prospect. BRIEF DESCRIPTION OF DRAWINGS

[0041] Figure 1 A flowchart of a preparation method of an emulsion based on a synergistic stabilization mechanism of polysaccharide molecules and polysaccharide microgels provided by the application is shown in the drawings;

[0042] Figure 2 The appearance of the emulsion prepared in Examples 1-4 and Comparative Examples 1 and 2 of the application;

[0043] Figure 3 The microstructure of the emulsion prepared in Examples 1-4 and Comparative Examples 1 and 2 of the application;

[0044] Figure 4 The freeze-thaw stability of the emulsion prepared in Examples 1-4 and Comparative Examples 1 and 2 of the application. DETAILED DESCRIPTION

[0045] The technical solutions of the application will be described below in conjunction with the embodiments, obviously, the described embodiments are only part of the embodiments of the application, rather than all the embodiments. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative labor belong to the protection scope of the application.

[0046] The reagents used in the examples and comparative examples can be commonly purchased from the market if not specially specified. The instruments used in the examples and comparative examples: homogenizer model T18 (IkA).

[0047] The present application provides a preparation method of emulsion based on synergistic stabilization mechanism of polysaccharide molecules and polysaccharide microgel, comprising the following steps:

[0048] Step 1: dissolve polysaccharide with helical structure (combination of one or more of agar, carrageenan, pectin) in deionized water, heat and stir until completely dissolved to obtain a homogeneous solution; under heating conditions, add salt solution dropwise to the homogeneous solution, and naturally cool under continuous shearing conditions to form a polysaccharide microgel suspension with a polysaccharide content of 0.2wt.% to 0.5wt.%; (when the polysaccharide with helical structure is agar, no salt solution needs to be added, and the homogeneous solution is directly naturally cooled under continuous shearing conditions)

[0049] Step 2: mix the polysaccharide microgel suspension with an oil phase (combination of one or more of soybean oil, peanut oil, corn oil, sunflower oil) in a mass ratio of 8:2 to 7:3, and high-speed shear at a speed of 8000 to 12000 rpm for 2 to 3 minutes to form a first mixture;

[0050] Step 3: add galactomannan (combination of one or more of fenugreek gum, guar gum, tara gum, locust bean gum) to water, heat and dissolve at 70 to 90°C under stirring conditions at a speed of 300 to 500 rpm for 20 to 40 minutes to obtain a second mixture with a galactomannan content of 0.4wt.% to 1.0wt.%;

[0051] Step 4: add the first mixture to the second mixture in a mass ratio of 1:1 to 1:1.5, and mix at a speed of 500 to 1000 rpm for 5 to 10 minutes to obtain an emulsion based on synergistic stabilization mechanism of polysaccharide molecules and polysaccharide microgel.

[0052] The present application will be further described below in conjunction with specific examples, but not as a limitation of the present application.

[0053] The kappa-carrageenan used in Examples 1-5 and Comparative Examples 1 and 2 was purchased from Shanghai Aladdin Biochemical Technology Co., Ltd. and was a water-soluble polymeric galactose sulfate containing repeating disaccharide units extracted from red seaweed, with a molecular weight of 788.66 kDa. Its linear backbone was composed of α-(1, 3)-D-4-sulfate-galactose and β-(1, 4)-3, 6-endothelial-D-galactose. The agar used in Example 6 was purchased from Fujian Marine Biological Technology Co., Ltd. and had a molecular weight of 33.75 kDa.

[0054] The locust bean gum used in Examples 1-4, 6 and Comparative Examples 1 and 2 was purchased from Shanghai Maikelin Biochemical Technology Co., Ltd., with a molecular weight of 226.66 kDa; the guar gum used in Example 5 was purchased from Shanghai Aladdin Biochemical Technology Co., Ltd., with a molecular weight of 327.29 kDa. Both locust bean gum and guar gum are galactomannans, consisting of a linear backbone of D-mannose units linked by β-(1, 4)-glycosidic bonds and D-galactose side groups linked by α-(1, 6)-glycosidic bonds.

[0055] Figure 1 A flowchart of a preparation method of an emulsion based on the synergistic stabilization mechanism of locust bean gum molecules and κ-carrageenan microgels for Examples 1-4 of the present application. The preparation method uses a step-by-step emulsification strategy. First, κ-carrageenan molecules (KC) are used as raw materials to prepare microgels (KCMs); then KCMs are used as emulsifiers to form emulsions stabilized by KCMs through high-speed shearing; finally, the emulsion stabilized by KCMs is mixed with locust bean gum molecules (LBG) to cover a layer of LBG on the surface of the emulsion droplets to construct a multi-layer interface structure and improve the stability of the emulsion by enhancing the mechanical strength of the interface layer.

[0056] Example 1

[0057] An emulsion based on the synergistic stabilization mechanism of polysaccharide molecules and polysaccharide microgels and a preparation method thereof, comprising the following steps:

[0058] Step 1: Dissolve carrageenan powder in deionized water at a mass fraction of 2.0 wt.%, heat and stir in a water bath at 75°C until completely dissolved, set the magnetic stirring speed to 400 rpm, stir and heat for 30 min to completely dissolve, and prepare a carrageenan solution; under water bath heating, slowly and uniformly add a KCl solution to the first mixture so that the final KCl concentration is 62.5 mM and the final carrageenan concentration is 0.4 wt.%; cool naturally during continuous shearing to prepare a carrageenan microgel suspension; in the suspension, the particle size of the carrageenan microgels is 4.54 ± 0.73 μm;

[0059] Step 2: Mix the carrageenan microgel suspension with soybean oil at a mass ratio of 4:1, high-speed disperse at 12000 rpm for 2 min to prepare a carrageenan microgel emulsion;

[0060] Step 3: Dissolve locust bean gum powder in deionized water at a mass fraction of 1.0 wt.%, heat and stir in a water bath at 85°C until completely dissolved, set the magnetic stirring speed to 400 rpm, stir and heat for 30 min to completely dissolve, and prepare a locust bean gum solution with a viscosity of 274.95 mPa*s;

[0061] Step 4: Slowly add the carrageenan microgel emulsion to the locust bean gum solution at a mass ratio of 1:1, and continuously stir at 800 rpm for 5 min to obtain a water-in-oil emulsion stabilized by polysaccharide molecules and polysaccharide microgels in cooperation.

[0062] Example 2

[0063] An emulsion based on a polysaccharide molecule and polysaccharide microgel cooperative stabilization mechanism and a preparation method thereof, comprising the following steps:

[0064] Step 1: Dissolve carrageenan powder in deionized water at a mass fraction of 2.0 wt.%, heat and stir in a water bath at 75°C until completely dissolved, set the magnetic stirring speed to 400 rpm, stir and heat for 30 min to completely dissolve, prepare a carrageenan solution; slowly and uniformly add a KCl solution to the first mixture under water bath heating conditions, so that the final KCl concentration is 62.5 mM and the final carrageenan concentration is 0.4 wt.%, and prepare a carrageenan microgel suspension under continuous shearing;

[0065] Step 2: Mix the carrageenan microgel suspension with peanut oil at a mass ratio of 4:1, and disperse at 15000 rpm for 2 min to prepare a carrageenan microgel emulsion;

[0066] Step 3: Dissolve locust bean gum powder in deionized water at a mass fraction of 0.8 wt.%, heat and stir in a water bath at 85°C until completely dissolved, set the magnetic stirring speed to 400 rpm, stir and heat for 30 min to completely dissolve, prepare a locust bean gum solution, and the viscosity is 154.03 mPa*s;

[0067] Step 4: Slowly add the carrageenan microgel emulsion to the locust bean gum solution at a mass ratio of 1:1, and continuously stir at 800 rpm for 5 min to obtain a water-in-oil emulsion stabilized by polysaccharide molecules and polysaccharide microgels in cooperation.

[0068] Example 3

[0069] An emulsion based on a polysaccharide molecule and polysaccharide microgel cooperative stabilization mechanism and a preparation method thereof, comprising the following steps:

[0070] Step 1: Dissolve carrageenan powder in deionized water at a mass fraction of 2.0 wt.%, heat and stir in a water bath at 75°C until completely dissolved, set the magnetic stirring speed to 400 rpm, stir and heat for 30 min to completely dissolve, prepare a carrageenan solution; slowly and uniformly add a KCl solution to the first mixture under water bath heating conditions, so that the final KCl concentration is 62.5 mM and the final carrageenan concentration is 0.4 wt.%, and prepare a carrageenan microgel suspension under continuous shearing;

[0071] Step 2: The carrageenan microgel suspension was mixed with corn oil at a mass ratio of 4:1, and dispersed at a high speed of 15000 rpm for 2 min to prepare a carrageenan microgel emulsion;

[0072] Step 3: The locust bean gum powder was dissolved in deionized water at a mass fraction of 0.6 wt.%, and heated and stirred in a water bath at 85°C until completely dissolved. The magnetic stirring speed was set to 400 rpm, and the stirring and heating were continued for 30 min to completely dissolve the locust bean gum powder, thereby preparing a locust bean gum solution with a viscosity of 80.37 mPa*s;

[0073] Step 4: The carrageenan microgel emulsion was slowly added to the locust bean gum solution at a mass ratio of 1:1, and stirred at 800 rpm for 5 min to obtain a water-in-oil emulsion stabilized by polysaccharide molecules and polysaccharide microgels.

[0074] Example 4

[0075] An emulsion based on a polysaccharide molecule and polysaccharide microgel synergistic stabilization mechanism and a preparation method thereof, comprising the following steps:

[0076] Step 1: The carrageenan powder was dissolved in deionized water at a mass fraction of 2.0 wt.%, and heated and stirred in a water bath at 75°C until completely dissolved. The magnetic stirring speed was set to 400 rpm, and the stirring and heating were continued for 30 min to completely dissolve the carrageenan powder, thereby preparing a carrageenan solution. Under the condition of water bath heating, the KCl solution was slowly and uniformly added to the first mixture, so that the final KCl concentration was 62.5 mM and the final carrageenan concentration was 0.4 wt.%. The natural cooling was carried out in the process of continuous shearing to prepare a carrageenan microgel suspension;

[0077] Step 2: The carrageenan microgel suspension was mixed with sunflower oil at a mass ratio of 4:1, and dispersed at a high speed of 15000 rpm for 2 min to prepare a carrageenan microgel emulsion;

[0078] Step 3: The locust bean gum powder was dissolved in deionized water at a mass fraction of 0.4 wt.%, and heated and stirred in a water bath at 85°C until completely dissolved. The magnetic stirring speed was set to 400 rpm, and the stirring and heating were continued for 30 min to completely dissolve the locust bean gum powder, thereby preparing a locust bean gum solution with a viscosity of 28.61 mPa*s;

[0079] Step 4: The carrageenan microgel emulsion was slowly added to the locust bean gum solution at a mass ratio of 1:1, and stirred at 800 rpm for 5 min to obtain a water-in-oil emulsion stabilized by polysaccharide molecules and polysaccharide microgels.

[0080] Example 5

[0081] An emulsion based on the synergistic stabilization mechanism of polysaccharide molecules and polysaccharide microgels and a preparation method thereof, comprising the following steps:

[0082] Step 1: carrageenan powder is dissolved in deionized water according to a mass fraction of 1.0 wt.%, heated and stirred in a water bath at 75°C until completely dissolved, the magnetic stirring speed is set to 300 rpm, and the stirring and heating is continued for 30 min to completely dissolve, to prepare a carrageenan solution; under water bath heating, KCl solution is slowly and uniformly added to the first mixture, so that the final KCl concentration is 62.5 mM and the final carrageenan concentration is 0.2 wt.%; the suspension is naturally cooled during continuous shearing to prepare a carrageenan microgel suspension; in the suspension, the particle size of the carrageenan microgel is 8.59±0.62 μm;

[0083] Step 2: the carrageenan microgel suspension is mixed with soybean oil at a mass ratio of 7:3, and high-speed dispersion is carried out at 15000 rpm for 2 min to prepare a carrageenan microgel emulsion;

[0084] Step 3: guar gum powder is dissolved in deionized water according to a mass fraction of 0.8 wt.%, heated and stirred in a water bath at 85°C until completely dissolved, the magnetic stirring speed is set to 400 rpm, and the stirring and heating is continued for 30 min to completely dissolve, to prepare a guar gum solution with a viscosity of 170.32 mPa*s;

[0085] Step 4: the carrageenan microgel emulsion is slowly added to the guar gum solution at a mass ratio of 1:1, and stirring is continuously carried out at 800 rpm for 5 min to obtain a water-in-oil emulsion synergistically stabilized by polysaccharide molecules and polysaccharide microgels.

[0086] Example 6

[0087] An emulsion based on the synergistic stabilization mechanism of polysaccharide molecules and polysaccharide microgels and a preparation method thereof, comprising the following steps:

[0088] Step 1: agar powder is dissolved in deionized water according to a mass fraction of 2.0 wt.%, heated and stirred in a water bath at 75°C until completely dissolved, the magnetic stirring speed is set to 400 rpm, and the stirring and heating is continued for 30 min to completely dissolve, to prepare an agar microgel suspension; the suspension is naturally cooled during continuous shearing to prepare an agar microgel suspension; in the suspension, the final agar concentration is 0.5 wt.%, and the particle size of the agar microgel is 3.67±0.04 μm;

[0089] Step 2: the agar microgel suspension is mixed with soybean oil at a mass ratio of 4:1, and high-speed dispersion is carried out at 15000 rpm for 2 min to prepare an agar microgel emulsion;

[0090] Step 3: Prepare locust bean gum solution by dissolving locust bean gum powder in deionized water at a mass fraction of 0.8% and heating in a water bath at 85°C with stirring until completely dissolved, with a magnetic stirring speed of 400 rpm, and stirring and heating for 30 min to ensure complete dissolution. The viscosity of the locust bean gum solution is 154.03 mPa*s;

[0091] Step 4: Slowly add agar microgel emulsion to the locust bean gum solution at a mass ratio of 1:1.5, and continue stirring at 800 rpm for 5 min to obtain a water-in-oil emulsion stabilized by polysaccharide molecules and polysaccharide microgels.

[0092] Comparative Example 1

[0093] The difference between this comparative example and Example 1 is that the concentration of locust bean gum in Step 3 is adjusted to 0%, and the other conditions and steps remain unchanged.

[0094] Comparative Example 2

[0095] The difference between this comparative example and Example 1 is that the concentration of locust bean gum in Step 3 is adjusted to 0.2 wt.%, and the other conditions and steps remain unchanged.

[0096] Performance Test

[0097] The emulsions prepared in Examples 1-4 and Comparative Examples 1 and 2 were subjected to performance testing, including macroscopic storage stability, microscopic structure, and freeze-thaw stability analysis of the emulsion.

[0098] The macroscopic storage stability analysis of the emulsion included placing the prepared emulsion at 25°C for 7 days, taking a photo to record the macroscopic morphology of the emulsion, and observing whether the emulsion showed signs of instability such as demulsification, flocculation, and creaming. The emulsion morphology is shown in Figure 2 .

[0099] Microscopic structure observation of the emulsion included observing the emulsion samples stored for 0d and 7d under a microscope. The microscopic structure of the emulsion is shown in Figure 3 .

[0100] The freeze-thaw stability analysis of the emulsion included freezing the prepared fresh emulsion at -20°C for 20h to completely freeze the sample, and then placing the completely frozen sample at 25°C for 4h to completely thaw the sample, and observing the macroscopic stability of the thawed sample. The freeze-thaw stability of the emulsion is shown in Figure 4 .

[0101] The emulsions prepared by the preparation method provided by the present application in Examples 1-4 are only stabilized by natural polysaccharides and have stable macroscopic morphology, and the stability of the emulsions is significantly improved compared with Comparative Examples 1 and 2. No obvious phase separation, flocculation and creaming occurs in Examples 1-4 during 7 days of storage; while macroscopically visible demulsification and creaming occur in Comparative Examples 1 and 2 during storage, and microstructure instability occurs in 1 day of storage.

[0102] Further, the emulsions prepared in Examples 1-4 also have better freeze-thaw stability, and still have stable macroscopic morphology after three freeze-thaw cycles (freezing at-20℃ for 20h to make the sample completely frozen; then completely frozen sample is placed at 25℃ for 4h to make the sample completely thawed; repeating the above operation three times); while macroscopically visible demulsification and creaming occur in Comparative Examples 1 and 2, respectively.

[0103] In summary, the emulsion based on the synergistic stabilization mechanism of polysaccharide molecules and polysaccharide microgels and the preparation method thereof provided by the present application not only effectively improve the macroscopic and microscopic stability of the emulsion, but also endow the emulsion with good freeze-thaw stability, and have the advantages of low cost and simple preparation process.

[0104] The above is only the preferred embodiment of the present application, and does not limit the implementation and protection scope of the present application. It should be realized by those skilled in the art that any equivalent replacement and obvious changes made by applying the content of the present application should be included in the protection scope of the present application.

Claims

1. A method for the preparation of an emulsion based on the synergistic stabilization mechanism of polysaccharide molecules and polysaccharide microgels, characterized in that, The method comprises the following steps: S1, using polysaccharide with helical structure as raw material, preparing polysaccharide microgel suspension with polysaccharide content of 0.2 wt%-0.5 wt%; the polysaccharide with helical structure is κ-carrageenan; S2, mixing the polysaccharide microgel suspension and oil phase according to a mass ratio of 8:2-7:3, and high-speed shearing to form a first mixture; S3, adding galactomannan to water, dissolving by heating to obtain a second mixture with galactomannan content of 0.4 wt%-1.0 wt%; the galactomannan is locust bean gum; S4, adding the first mixture to the second mixture according to a mass ratio of 1:1-1:1.5, and mixing to obtain an emulsion based on polysaccharide molecule and polysaccharide microgel synergistic stabilization mechanism.

2. The production method according to claim 1, characterized by, In step S1, the preparation method of the polysaccharide microgel suspension comprises: dissolving the polysaccharide with helical structure in deionized water, heating and stirring until completely dissolved to obtain a homogeneous solution; under heating conditions, adding a salt solution dropwise to the homogeneous solution, and naturally cooling under continuous shearing conditions to form a polysaccharide microgel suspension.

3. The production method according to claim 1, characterized by, In step S1, the particle size of the polysaccharide microgel in the polysaccharide microgel suspension is 1-10 μm.

4. The method of claim 1, wherein, In step S2, the oil phase comprises one or more combinations of soybean oil, peanut oil, corn oil, and sunflower seed oil.

5. The production method according to claim 1, characterized by, In step S2, the high-speed shearing speed is 8000-12000 rpm, and the time is 2-3 min.

6. The production method according to claim 1, characterized by, In step S4, the stirring speed of the mixing is 500-1000 rpm, and the time is 5-10 min.

7. An emulsion based on synergistic stabilization mechanism of polysaccharide molecules and polysaccharide microgels, characterized in that, Prepared by the preparation method according to any one of claims 1-6.

8. Use of the emulsion based on polysaccharide molecule and polysaccharide microgel synergistic stabilization mechanism according to claim 7 in food engineering.

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