Method of preparing and using plant meat roast beef flavor composite pickering emulsion

Abstract

The application provides a preparation method and use method of a roast beef flavor composite Pickering emulsion for plant meat, and the preparation method comprises the following steps: mixing a soybean protein isolate solution and a chitosan solution, and then heating at 90 DEG C for 8-16 min; the mass ratio of the soybean protein isolate to the chitosan in the mixed solution is 3:1-1:5; after the mixed solution is cooled to room temperature, the pH value is adjusted to 2.5-4.5; plant oil containing roast beef flavor is added into the mixed solution, and homogenization is performed, so that the roast beef flavor composite Pickering emulsion is obtained. The composite Pickering emulsion can improve the oxidation and deterioration problem of meat flavor in the processing of plant meat products, and at the same time, slow release of aroma can be realized, and the sensory quality of the plant meat products is enhanced.

Description

Technical Field

[0001] This invention belongs to the field of food processing technology, and particularly relates to the field of plant-based meat and its related additives. Specifically, it relates to a method for preparing and using a plant-based meat roast beef flavoring compound Pickering emulsion. Background Technology

[0002] Meat flavorings are a common type of food additive that helps improve the texture and flavor of meat products and, to some extent, compensates for flavor loss that may occur during meat processing. Aroma has a significant impact on the taste of meat; some common aromas can be used to distinguish different types of meat or different processing methods, including basic meat aromas, characteristic meat aromas, caramel aromas, roasted aromas, smoky aromas, onion and garlic aromas, and spicy aromas. Plant-based meat, made primarily from plant proteins such as soy protein, pea protein, and wheat protein, is formulated through pretreatment, seasoning, binding, and shaping processes. It boasts unique flavor and texture, as well as health benefits, and has gained increasing popularity and attention from consumers in recent years. Therefore, the application of meat flavorings in plant-based meat is gradually increasing. Studies have shown that the addition of flavorings can effectively improve the flavor of plant-based meat, making it closer to the aroma of real meat.

[0003] Nevertheless, most flavor compounds in meat flavorings are volatile. Not only do they significantly reduce the sensory properties of food after being released from the solid food matrix, but they are also susceptible to changes in aroma due to environmental factors such as light, oxygen, temperature, humidity, and pH. Furthermore, meat flavorings serve as a natural culture medium for microorganisms, making them prone to spoilage and limiting their preservation and use.

[0004] Encapsulation is one of the most effective and widely used methods to improve the stability of flavor profiles and reduce their loss. The basic principle involves encapsulating the flavor profile within a carrier composed of food-grade materials (including polysaccharides, proteins, lipids, and their complexes). Currently, the main flavor encapsulation methods include microcapsules, nanoparticles, emulsions, and composite coagulation encapsulation. Among these, an emulsion is a stable system composed of two immiscible liquids in their natural state. When specific solid particles are used as stabilizers, such an emulsion is called a Pickering emulsion. Compared to traditional emulsions, Pickering emulsions have lower toxicity, higher anti-agglomeration stability, and stronger storage stability. Furthermore, it can encapsulate active substances and provide protection, delivery, and controlled release. Natural macromolecules such as proteins, polysaccharides, and lipids are typically used as the solid particles stabilizing the emulsion.

[0005] However, no team has yet attempted to use Pickering emulsions to encapsulate meat flavorings for quality improvement in plant-based meat products, including flavor and texture. Therefore, obtaining a highly stable meat flavoring emulsion that can improve the quality of plant-based meat is a problem that needs to be solved. Summary of the Invention

[0006] To overcome the shortcomings of existing technologies, the present invention aims to provide a method for preparing and using a compound emulsion of roasted beef flavoring that can be used to improve the quality of plant-based meat. This method addresses the problems of flavor loss and oxidative deterioration of roasted beef flavoring during the processing of plant-based meat products, and can significantly enhance the sensory quality of plant-based protein meat. One objective of the present invention is achieved through the following technical solution:

[0007] A method for preparing a plant-based roasted beef flavoring compound Pickering emulsion includes the following steps:

[0008] Step 1: Weigh out soy protein isolate and chitosan;

[0009] Step 2, Prepare soy protein isolate solution: Dissolve soy protein isolate in water to prepare a solution;

[0010] Step 3, prepare chitosan solution: Dissolve chitosan in 1% acetic acid to prepare a solution;

[0011] Step 4, Mixing solution: Mix the soy protein isolate solution and chitosan solution and heat at 90°C for 8-16 minutes; the mass ratio of soy protein isolate to chitosan in the mixed solution is 3:1 to 1:5.

[0012] Step 5, Adjust pH: After the mixed solution cools to room temperature, adjust the pH to 2.5–4.5;

[0013] Step 6, Emulsion Preparation: Add vegetable oil containing roasted beef flavoring to the mixed solution and homogenize to obtain the roasted beef flavoring composite Pickering emulsion; the flavor components of roasted beef flavoring include: furfuryl methyl disulfide, 2-methyl-3-methylthiofuran, 2,3,5-trimethylpyrazine and ethyl octanoate, and the mass of roasted beef flavoring accounts for 0.8% to 1.2% of the mass of the roasted beef flavoring composite Pickering emulsion; the vegetable oil is liquid at room temperature, and the volume of the vegetable oil accounts for 38% to 42% of the volume of the roasted beef flavoring composite Pickering emulsion.

[0014] Further optimization, step 2, prepare soy protein isolate solution: dissolve soy protein isolate in water to prepare a solution, stir magnetically for 4 hours, and hydrate overnight at 4°C for later use; step 3, prepare chitosan solution: dissolve chitosan in 1% acetic acid to prepare a solution, stir magnetically for 4 hours, and hydrate overnight at 4°C.

[0015] Furthermore, the soy protein isolate solution prepared in step 2 and the chitosan solution prepared in step 3 have the same mass concentration.

[0016] Furthermore, in step 4, the soy protein isolate solution and chitosan solution are mixed and heated at 90°C for 12 minutes. In step 4, the mass ratio of soy protein isolate to chitosan in the mixed solution is 1:3.

[0017] Further, in step 5, adjust the pH value: after the mixed solution has cooled to room temperature, adjust the pH value to 3.5.

[0018] Furthermore, in step 6: the vegetable oil is sunflower seed oil, and the volume of the vegetable oil accounts for 40% of the volume of the roast beef flavoring compound Pickering emulsion. Furthermore, the mass concentration of roast beef flavoring in the vegetable oil is 2.5%.

[0019] Another objective of the present invention is achieved by the following means:

[0020] The roasted beef flavoring compound Pickering emulsion is added to the plant protein semi-finished product used to make plant-based meat so that the final flavoring addition amount reaches 1-3 mg / g. After mixing, it is placed in a mold to form and roasted to obtain the finished plant-based meat.

[0021] The specific mechanism of the Pickering emulsion-stabilized flavor of this invention is as follows: First, the charged part of the soy protein isolate / chitosan complex can be adsorbed on the oil-water interface to form a thin film coating the droplets; second, during the preheating treatment of the protein / polysaccharide complex solution, the original flocculated structure of the protein opens and denatures, resulting in the exposure of hydrophobic groups. The internal forces of the originally flocculated protein are mainly relatively weak non-covalent bond interactions, such as hydrogen bonds and hydrophobic interactions. These interactions may be destroyed during the heating process; at the same time, the protein molecule structure usually unfolds and exposes a large number of hydrophobic groups during the heating process, resulting in an increase in surface hydrophobicity and free thiol groups. Under the influence of hydrophobic interactions and disulfide bonds, proteins re-aggregate to form flocculent particles, enhancing the cohesive force of the particles and thus resisting interfacial tension disruption to maintain their integrity, thereby stabilizing the particle interface. The addition of vegetable oil can promote the dispersion and stability of the complex in the aqueous phase. The vegetable oil containing the flavoring interacts with the protein / polysaccharide complex, forming tiny droplets in the aqueous phase, which are then coated by the protein / polysaccharide complex, ultimately forming a stable Pickering emulsion. This emulsion has a significant slow-release effect on the release of aroma compounds in roast beef flavoring.

[0022] The advantages of this invention compared to the prior art are as follows:

[0023] 1) In the roast beef flavor compound Pickering emulsion of the present invention, soy protein isolate combined with chitosan is used as a particle stabilizer, and vegetable oil containing roast beef flavor is used as the oil phase to prepare the Pickering emulsion. Soy protein isolate can undergo non-covalent interactions (electrostatic interactions, hydrogen bonds, and hydrophobic interactions, etc.) with chitosan under acidic conditions to form a complex. By adjusting the ratio of soy protein isolate / chitosan solution, pH, preheating time, and adding vegetable oil, a compound emulsion with significantly improved roast beef flavor stability is prepared.

[0024] 2) When the roast beef flavoring compound emulsion of the present invention is added to plant-based meat products, it can significantly reduce the loss of exogenous aroma of plant-based meat, and improve its texture quality while enhancing the flavor of plant-based meat. Attached Figure Description

[0025] Figure 1 The encapsulation rates of the roast beef flavoring composite Pickering emulsions prepared in Examples 1-8 and Comparative Examples 1-5 are shown. Figure 1 (a) to (c) correspond to changes in pH, protein / chitosan ratio, and heat treatment temperature, respectively.

[0026] Figure 2 Infrared spectral analysis and rheological properties of the roast beef flavor composite Pickering emulsion prepared in Example 1; Figure 2 (a) to 2(c) correspond to different measurement indicators.

[0027] Figure 3 The microstructure of the roast beef flavoring composite Pickering emulsion prepared in Example 1 is shown; wherein... Figure 3 A shows a microscopic image of the emulsion stained with both Nile Red and Nile Blue. Figure 3 B and Figure 3 C shows microscopic images stained with Nile blue and Nile red, respectively; Figure 3 A1 shows a microscopic image of the emulsion simultaneously stained with Nile Blue and Fluorescein Isothiocyanate; Figure 3 B1 and Figure 3 C1 shows microscopic images of the emulsion stained with Nile blue and fluorescein isothiocyanate, respectively.

[0028] Figure 4 The release curves of characteristic flavor compounds in the Pickering emulsion containing roasted beef flavoring prepared in Example 1 at different heating times are shown.

[0029] Figure 5 The sustained-release effect of adding plant-based meat to roast beef flavoring (a) and the negative roast beef flavoring compound Pickering emulsion (b) prepared in Example 1 on characteristic flavor compounds.

[0030] Figure 6 The particle size and polydispersity index of the soybean protein isolate / chitosan composite Pickering emulsions prepared in Examples 1-13; Figure 6 (a) to 6(c) correspond to changes in pH, protein / chitosan ratio, and heat treatment temperature, respectively.

[0031] Figure 7 The zeta potential of the soybean protein isolate / chitosan composite Pickering emulsions prepared in Examples 1-13; Figure 7 (a) to 7(c) correspond to changes in pH, protein / chitosan ratio, and heat treatment temperature, respectively.

[0032] Figure 8 The emulsifying activity and emulsifying stability of the soybean protein isolate / chitosan composite Pickering emulsions prepared in Examples 1-13 were studied. Figure 8 (a) to 8(c) correspond to changes in pH, protein / chitosan ratio, and heat treatment temperature, respectively. Detailed Implementation

[0033] The present invention will now be further described in conjunction with specific embodiments. It should be noted that, without conflict, the various embodiments or technical features described below can be arbitrarily combined to form new embodiments.

[0034] Example 1

[0035] This embodiment provides a method for preparing a Pickering emulsion, a compound flavoring for roasted beef used in plant-based meat products. The preparation method includes the following steps:

[0036] Step 1: Weigh out a certain amount of soy protein isolate and chitosan;

[0037] Step 2, prepare soy protein isolate solution: Dissolve soy protein isolate in water to prepare a 2% (w / w) solution, stir magnetically for 4 hours, and incubate overnight at 4°C;

[0038] Step 3, prepare chitosan solution: Dissolve chitosan in 1% acetic acid to prepare a 2% (w / w) solution, stir magnetically for 4 hours, and incubate overnight at 4°C.

[0039] Step 4, Mixing the solution: Mix the soy protein isolate solution and the chitosan solution at a volume ratio of 1:3 and heat at 90°C for 12 minutes; at this time, the mass ratio of soy protein isolate to chitosan is 1:3.

[0040] Step 5, pH adjustment: After the mixed solution cools to room temperature, adjust the pH of the solution to 3.5 using 1% hydrochloric acid and 1% sodium hydroxide; room temperature is 18-30℃.

[0041] Step 6, Emulsion preparation: Add sunflower seed oil containing roast beef flavor (2.5%) to the mixed solution to make the volume ratio of oil phase to water phase 2:3 (i.e., the volume of sunflower seed oil accounts for 40% of the total volume). Homogenize at 12000 r / min for 4 min to obtain roast beef flavor composite Pickering emulsion.

[0042] The types and contents of flavor compounds in the roast beef flavoring used in this embodiment are shown in Table 1.

[0043] The composite Pickering emulsion prepared achieved an encapsulation rate of roast beef flavor as shown in the figure. Figure 1 (a) Figure 1 (b) and Figure 1 The peak value is shown in (c).

[0044] The soy protein isolate described in this embodiment was manufactured by Shandong Yuwang Industrial Co., Ltd., product model YP928Z; the chitosan was purchased from Shanghai Yuanye Biotechnology Co., Ltd., product model S11064; the roast beef flavor was manufactured by Givaudan AG, Switzerland, product model L-260032; and the sunflower seed oil (Xishijia) was purchased from Cargill Asia Pacific Food Systems (Beijing) Co., Ltd.

[0045] Example 2

[0046] This embodiment provides a method for preparing a plant-based roasted beef flavoring compound Pickering emulsion. The raw materials used are the same as in Example 1, but the preparation method differs from that in Example 1 in the following ways:

[0047] In step 4, the mixed solution is prepared by mixing the soy protein isolate solution and the chitosan solution at a volume ratio of 3:1 and then heating at 90°C for 12 minutes.

[0048] The composite Pickering emulsion prepared achieved an encapsulation rate of roast beef flavor as shown in the figure. Figure 1 As shown in (b).

[0049] Example 3

[0050] This embodiment provides a method for preparing a plant-based roasted beef flavoring compound Pickering emulsion. The raw materials used are the same as in Example 1, but the preparation method differs from that in Example 1 in the following ways:

[0051] In step 4, the mixed solution is prepared by mixing the soy protein isolate solution and the chitosan solution at a volume ratio of 1:1 and then heating at 90°C for 12 minutes.

[0052] The composite Pickering emulsion prepared achieved an encapsulation rate of roast beef flavor as shown in the figure. Figure 1 As shown in (b).

[0053] Example 4

[0054] This embodiment provides a method for preparing a plant-based roasted beef flavoring compound Pickering emulsion. The raw materials used are the same as in Example 1, but the preparation method differs from that in Example 1 in the following ways:

[0055] In step 4, the mixed solution is prepared by mixing the soy protein isolate solution and the chitosan solution at a volume ratio of 1:5 and then heating at 90°C for 12 minutes.

[0056] The composite Pickering emulsion prepared achieved an encapsulation rate of roast beef flavor as shown in the figure. Figure 1 As shown in (b).

[0057] Example 5

[0058] This embodiment provides a method for preparing a plant-based roasted beef flavoring compound Pickering emulsion. The raw materials used are the same as in Example 1, but the preparation method differs from that in Example 1 in the following ways:

[0059] In step 4, the mixed solution is prepared by mixing the soy protein isolate solution and the chitosan solution at a volume ratio of 1:3 and then heating at 90°C for 8 minutes.

[0060] The composite Pickering emulsion prepared achieved an encapsulation rate of roast beef flavor as shown in the figure. Figure 1 As shown in (c).

[0061] Example 6

[0062] This embodiment provides a method for preparing a plant-based roasted beef flavoring compound Pickering emulsion. The raw materials used are the same as in Example 1, but the preparation method differs from that in Example 1 in the following ways:

[0063] In step 4, the mixed solution is prepared by mixing the soy protein isolate solution and the chitosan solution at a volume ratio of 1:3 and then heating at 90°C for 16 minutes.

[0064] The composite Pickering emulsion prepared achieved an encapsulation rate of roast beef flavor as shown in the figure. Figure 1 As shown in (c).

[0065] Example 7

[0066] This embodiment provides a method for preparing a plant-based roasted beef flavoring compound Pickering emulsion. The raw materials used are the same as in Example 1, but the preparation method differs from that in Example 1 in the following ways:

[0067] Step 5, pH adjustment: After the mixed solution has cooled to room temperature, adjust the pH of the solution to 2.5 using 1% hydrochloric acid and 1% sodium hydroxide.

[0068] The composite Pickering emulsion prepared achieved an encapsulation rate of roast beef flavor as shown in the figure. Figure 1 As shown in (a).

[0069] Example 8

[0070] This embodiment provides a method for preparing a plant-based roasted beef flavoring compound Pickering emulsion. The raw materials used are the same as in Example 1, but the preparation method differs from that in Example 1 in the following ways:

[0071] Step 5, pH adjustment: After the mixed solution has cooled to room temperature, adjust the pH of the solution to 4.5 using 1% hydrochloric acid and 1% sodium hydroxide.

[0072] The composite Pickering emulsion prepared achieved an encapsulation rate of roast beef flavor as shown in the figure. Figure 1 As shown in (a).

[0073] Example 9

[0074] This embodiment is an application of embodiment 1.

[0075] In this embodiment, the roasted beef flavoring compound Pickering emulsion obtained in Example 1 was added to an aqueous solution of textured soybean protein and fibrous protein (mass ratio: 8:2) that was continuously stirred at 0-4℃ for 12 hours to achieve a final flavoring addition of 1-3 mg / g. After uniform stirring, the mixture was placed in a mold to form patties with a diameter of 10 cm and a thickness of 1.5 cm. The patties were baked at 180℃ for 12 minutes, and flipped after 6 minutes to continue baking, ensuring even baking. After baking, the samples were cut into uniformly sized pieces, mixed, and sampled for gas chromatography-mass spectrometry (GC-MS) and textural analysis. The results showed that adding the roasted beef flavoring compound emulsion significantly reduced aroma loss during the baking process of plant-based meat and improved its textural quality. Specific results are shown in Table 2 and... Figure 5 As shown.

[0076] Comparative Example 1

[0077] This comparative example provides a method for preparing a plant-based roasted beef flavoring compound Pickering emulsion. The raw materials used are the same as in Example 1, but the preparation method differs from that in Example 1 in the following ways:

[0078] In step 4, the mixed solution is prepared by mixing the soy protein isolate solution and the chitosan solution at a volume ratio of 5:1 and then heating at 90°C for 12 minutes.

[0079] The composite Pickering emulsion prepared achieved an encapsulation rate of roast beef flavor as shown in the figure. Figure 1 As shown in (b).

[0080] Comparative Example 2

[0081] This comparative example provides a method for preparing a plant-based roasted beef flavoring compound Pickering emulsion. The raw materials used are the same as in Example 1, but the preparation method differs from that in Example 1 in the following ways:

[0082] In step 4, the mixed solution is prepared by mixing the soy protein isolate solution and the chitosan solution at a volume ratio of 1:3 without heating.

[0083] The composite Pickering emulsion prepared achieved an encapsulation rate of roast beef flavor as shown in the figure. Figure 1 As shown in (c).

[0084] Comparative Example 3

[0085] This comparative example provides a method for preparing a plant-based roasted beef flavoring compound Pickering emulsion. The raw materials used are the same as in Example 1, but the preparation method differs from that in Example 1 in the following ways:

[0086] In step 4, the mixed solution is prepared by mixing the soy protein isolate solution and the chitosan solution at a volume ratio of 1:3 and then heating at 90°C for 4 minutes.

[0087] The composite Pickering emulsion prepared achieved an encapsulation rate of roast beef flavor as shown in the figure. Figure 1 As shown in (c).

[0088] Comparative Example 4

[0089] This comparative example provides a method for preparing a plant-based roasted beef flavoring compound Pickering emulsion. The raw materials used are the same as in Example 1, but the preparation method differs from that in Example 1 in the following ways:

[0090] Step 5, pH adjustment: After the mixed solution has cooled to room temperature, adjust the pH of the solution to 5.5 using 1% hydrochloric acid and 1% sodium hydroxide.

[0091] The composite Pickering emulsion prepared achieved an encapsulation rate of roast beef flavor as shown in the figure. Figure 1 As shown in (a).

[0092] Comparative Example 5

[0093] This comparative example provides a method for preparing a plant-based roasted beef flavoring compound Pickering emulsion. The raw materials used are the same as in Example 1, but the preparation method differs from that in Example 1 in the following ways:

[0094] Step 5, Adjust pH: After the mixed solution has cooled to room temperature, adjust the pH of the solution to 6.5 using 1% hydrochloric acid and 1% sodium hydroxide.

[0095] The composite Pickering emulsion prepared achieved an encapsulation rate of roast beef flavor as shown in the figure. Figure 1 As shown in (a).

[0096] Comparative Example 6

[0097] This comparative example provides a method for preparing a plant-based beef flavoring compound Pickering emulsion, which differs from Example 1 in that the polysaccharide is replaced with pea starch:

[0098] In step 3, prepare the pea starch solution: Dissolve the pea starch in deionized water to prepare a 2% (w / w) solution, stir magnetically for 4 hours, and incubate overnight at 4°C.

[0099] Comparative Example 7

[0100] This comparative example provides a method for preparing a plant-based roast beef flavoring compound Pickering emulsion. The difference between this method and Example 1 is that the polysaccharide is replaced with rice starch.

[0101] In step 3, prepare the rice starch solution: Dissolve the rice starch in deionized water to prepare a 2% (w / w) solution, stir magnetically for 4 hours, and incubate overnight at 4°C.

[0102] The following are 13 experimental examples. In order to obtain the optimal properties of Pickering emulsions, the research was conducted without adding fragrances to the vegetable oils. The details are as follows:

[0103] Experimental Example 1

[0104] This experimental example provides a soybean protein isolate / chitosan composite Pickering emulsion, the preparation method of which differs from that of Example 1 in the following ways:

[0105] Step 6, prepare the emulsion: add sunflower seed oil without any additional ingredients to make the volume ratio of oil phase to water phase of the system 2:3, and homogenize at 12000 r / min for 4 min.

[0106] Everything else is the same as in Example 1.

[0107] Experimental Example 2

[0108] This experimental example provides a soybean protein isolate / chitosan composite Pickering emulsion, the preparation method of which differs from that of Example 1 in the following ways:

[0109] In step 4, the mixed solution is prepared by mixing the soy protein isolate solution and the chitosan solution at a volume ratio of 5:1 and then heating at 90°C for 12 minutes.

[0110] Step 6, prepare the emulsion: add sunflower seed oil without any additional ingredients to make the volume ratio of oil phase to water phase of the system 2:3, and homogenize at 12000 r / min for 4 min.

[0111] Everything else is the same as in Example 1.

[0112] Experimental Example 3

[0113] This experimental example provides a soybean protein isolate / chitosan composite Pickering emulsion, the preparation method of which differs from that of Example 1 in the following ways:

[0114] In step 4, the mixed solution is prepared by mixing the soy protein isolate solution and the chitosan solution at a volume ratio of 3:1 and then heating at 90°C for 12 minutes.

[0115] Step 6, prepare the emulsion: add sunflower seed oil without any additional ingredients to make the volume ratio of oil phase to water phase of the system 2:3, and homogenize at 12000 r / min for 4 min.

[0116] Everything else is the same as in Example 1.

[0117] Experiment Example 4

[0118] This experimental example provides a soybean protein isolate / chitosan composite Pickering emulsion, the preparation method of which differs from that of Example 1 in the following ways:

[0119] In step 4, the mixed solution is prepared by mixing the soy protein isolate solution and the chitosan solution at a volume ratio of 1:1 and then heating at 90°C for 12 minutes.

[0120] Step 6, prepare the emulsion: add sunflower seed oil without any additional ingredients to make the volume ratio of oil phase to water phase of the system 2:3, and homogenize at 12000 r / min for 4 min.

[0121] Everything else is the same as in Example 1.

[0122] Experimental Example 5

[0123] This experimental example provides a soybean protein isolate / chitosan composite Pickering emulsion, the preparation method of which differs from that of Example 1 in the following ways:

[0124] In step 4, the mixed solution is prepared by mixing the soy protein isolate solution and the chitosan solution at a volume ratio of 1:5 and then heating at 90°C for 12 minutes.

[0125] Step 6, prepare the emulsion: add sunflower seed oil without any additional ingredients to make the volume ratio of oil phase to water phase of the system 2:3, and homogenize at 12000 r / min for 4 min.

[0126] Everything else is the same as in Example 1.

[0127] Experimental Example 6

[0128] This experimental example provides a soybean protein isolate / chitosan composite Pickering emulsion, the preparation method of which differs from that of Example 1 in the following ways:

[0129] In step 4, the mixed solution is prepared by mixing the soy protein isolate solution and the chitosan solution at a volume ratio of 1:3 without heating.

[0130] Step 6, prepare the emulsion: add sunflower seed oil without any additional ingredients to make the volume ratio of oil phase to water phase of the system 2:3, and homogenize at 12000 r / min for 4 min.

[0131] Everything else is the same as in Example 1.

[0132] Experimental Example 7

[0133] This experimental example provides a soybean protein isolate / chitosan composite Pickering emulsion, the preparation method of which differs from that of Example 1 in the following ways:

[0134] In step 4, the solution is mixed: the soy protein isolate solution and the chitosan solution are mixed at a volume ratio of 1:3 and then heated for 4 minutes.

[0135] Step 6, prepare the emulsion: add sunflower seed oil without any additional ingredients to make the volume ratio of oil phase to water phase of the system 2:3, and homogenize at 12000 r / min for 4 min.

[0136] Everything else is the same as in Example 1.

[0137] Experimental Example 8

[0138] This experimental example provides a soybean protein isolate / chitosan composite Pickering emulsion, the preparation method of which differs from that of Example 1 in the following ways:

[0139] In step 4, the mixed solution is prepared by mixing the soy protein isolate solution and the chitosan solution at a volume ratio of 1:3 and then heating for 8 minutes.

[0140] Step 6, prepare the emulsion: add sunflower seed oil without any additional ingredients to make the volume ratio of oil phase to water phase of the system 2:3, and homogenize at 12000 r / min for 4 min.

[0141] Everything else is the same as in Example 1.

[0142] Experimental Example 9

[0143] This experimental example provides a soybean protein isolate / chitosan composite Pickering emulsion, the preparation method of which differs from that of Example 1 in the following ways:

[0144] In step 4, the mixed solution is prepared by mixing the soy protein isolate solution and the chitosan solution at a volume ratio of 1:3 and then heating for 16 minutes.

[0145] Step 6, prepare the emulsion: add sunflower seed oil without any additional ingredients to make the volume ratio of oil phase to water phase of the system 2:3, and homogenize at 12000 r / min for 4 min.

[0146] Everything else is the same as in Example 1.

[0147] Experimental Example 10

[0148] This experimental example provides a soybean protein isolate / chitosan composite Pickering emulsion, the preparation method of which differs from that of Example 1 in the following ways:

[0149] Step 5, Adjust pH: After the solution cools to room temperature, adjust the pH of the solution to 2.5 using 1% hydrochloric acid and 1% sodium hydroxide.

[0150] Step 6, prepare the emulsion: add sunflower seed oil without any additional ingredients to make the volume ratio of oil phase to water phase of the system 2:3, and homogenize at 12000 r / min for 4 min.

[0151] Everything else is the same as in Example 1.

[0152] Experimental Example 11

[0153] This experimental example provides a soybean protein isolate / chitosan composite Pickering emulsion, the preparation method of which differs from that of Example 1 in the following ways:

[0154] Step 5, Adjust pH: After the solution cools to room temperature, adjust the pH of the solution to 4.5 using 1% hydrochloric acid and 1% sodium hydroxide.

[0155] Step 6, prepare the emulsion: add sunflower seed oil without any additional ingredients to make the volume ratio of oil phase to water phase of the system 2:3, and homogenize at 12000 r / min for 4 min.

[0156] Everything else is the same as in Example 1.

[0157] Experimental Example 12

[0158] This experimental example provides a soybean protein isolate / chitosan composite Pickering emulsion, the preparation method of which differs from that of Example 1 in the following ways:

[0159] Step 5, Adjust pH: After the solution cools to room temperature, adjust the pH of the solution to 5.5 using 1% hydrochloric acid and 1% sodium hydroxide.

[0160] Step 6, prepare the emulsion: add sunflower seed oil without any additional ingredients to make the volume ratio of oil phase to water phase of the system 2:3, and homogenize at 12000 r / min for 4 min.

[0161] Everything else is the same as in Example 1.

[0162] Experimental Example 13

[0163] This experimental example provides a soybean protein isolate / chitosan composite Pickering emulsion, the preparation method of which differs from that of Example 1 in the following ways:

[0164] Step 5, Adjust pH: After the solution cools to room temperature, adjust the pH of the solution to 6.5 using 1% hydrochloric acid and 1% sodium hydroxide.

[0165] Step 6, prepare the emulsion: add sunflower seed oil without any additional ingredients to make the volume ratio of oil phase to water phase of the system 2:3, and homogenize at 12000 r / min for 4 min.

[0166] Everything else is the same as in Example 1.

[0167] Results analysis:

[0168] The types and contents of flavor compounds detected by GC-MS in the roast beef flavoring used in Example 1 are shown in Table 1.

[0169] The encapsulation efficiency of the composite Pickering emulsions in Examples 1-8 and Comparative Examples 1-5 is as follows: Figure 1 As shown.

[0170] Infrared spectral analysis and rheological properties of the composite Pickering emulsion prepared in Example 1, its microstructure, and the release curves of its characteristic flavor compounds at different heating times are shown below. Figure 2 , Figure 3 , Figure 4 As shown (RBF is roast beef flavoring, SPI is soy protein isolate, and CS is chitosan).

[0171] The sustained-release effect of the composite Pickering emulsion prepared in Example 1 on characteristic flavor compounds after being added to plant-based meat is as follows: Figure 5 As shown.

[0172] The effect of adding the composite Pickering emulsion prepared in Example 1 to plant-based meat on its textural properties is shown in Table 2.

[0173] The particle size, polydispersity index (PDI), zeta potential, emulsifying activity (EAI), and emulsifying stability (ESI) of the soybean protein isolate / chitosan composite Pickering emulsions in Examples 1-13 are as follows: Figure 6 , Figure 7 , Figure 8 As shown.

[0174] Table 1. Concentration of various flavor compounds in roast beef flavoring

[0175] Chinese name Relative content (%) 2-Methylfuran 0.42 trans-2-nonanal 0.02 dimethyl disulfide 0.09 hexanol 1.46 Octal 0.23 2-Methyltetrahydrofuran-3-one 1.67 2-Methyltetrahydrofuran-3-thiol 2.75 2-Methyl-3-methylthiofuran 2 Methyl isopentyl disulfide 0.27 Methyl octanoate 1.14 2,3,5-Trimethylpyrazine 24.36 Pentylbenzene 0.28 trans-2-octenal 0.55 Ethyl octanoate 2.21 1-Octen-3-ol 0.9 furfural 4.7 Methyl nonyl ketone 0.05 Ethyl decanoate 0.21 trans-2-decenal 1.15 2-Acetylthiazole 3.09 furfuryl methyl disulfide 7.11 Guaiacol 1.2 4-Ethylresorcinol 0.1

[0176] Table 2. Effects of adding compound Pickering emulsion on the texture and quality of plant-based succulents.

[0177]

[0178] As shown in Table 1, GC-MS analysis identified 23 aroma compounds in the roast beef flavoring, including aromatic aldehydes, ketones, esters, and heterocyclic compounds. The main components were methyl furfuryl disulfide (7.11%), 2-methyl-3-methylthiofuran (2.0%), 2,3,5-trimethylpyrazine (24.36%), and ethyl octanoate (2.21%).

[0179] like Figure 1 As shown, Example 1 exhibited the highest encapsulation rate for roast beef flavoring, reaching 86.48%. With increasing chitosan ratio, the encapsulation rate of the emulsion for flavoring gradually increased; however, once the ratio of soy protein isolate to chitosan reached 1:3, further increases in chitosan content resulted in a decreased encapsulation rate. In Example 1, the ratio of soy protein isolate to chitosan was 1:3. Under this condition, the surface charge balance of the complex system was optimally maintained, the oil-water interfacial tension was minimal, and this was most conducive to oil droplet encapsulation. Figure 1 (b)).

[0180] like Figure 1 As shown in (c), the encapsulation rate of the composite Pickering emulsion for roast beef flavor initially increased and then decreased with increasing preheating time of the composite wall material solution. Example 1, prepared by preheating the soy protein isolate / chitosan solution for 12 min, exhibited the highest encapsulation rate for the flavor. During the optimal preheating time, acidic hydrolysis occurred between soy protein isolate and chitosan molecules. The hydroxyl groups in the polysaccharide molecules reacted chemically with the carboxyl groups in the protein, forming acid and salt groups, initiating cross-linking and gelation. This also caused the protein molecules to aggregate and form a stable and regular network structure.

[0181] like Figure 1As shown in (a), the protein-polysaccharide complex prepared in Example 1 at pH 3.5 has the lowest surface charge, which can effectively reduce the adsorption of flavor by charge repulsion, making it easier for the flavor to be encapsulated inside the composite Pickering emulsion. At the same time, the molecular structure of soy protein isolate changes, which enhances its hydrophilicity and intermolecular forces, facilitating the formation of a stable complex with chitosan and further improving the encapsulation rate of the flavor.

[0182] Depend on Figure 2 (a) It can be seen that when soy protein isolate and chitosan form a composite Pickering emulsion, the hydroxyl absorption peak undergoes a blue shift, indicating that there is a strong hydrogen bonding effect in the composite Pickering emulsion.

[0183] Figure 2 The results in (b) indicate that the emulsion exhibits pseudoplastic fluid characteristics. As the shear rate increases, the viscosity of the emulsion decreases continuously, which is a shear thinning phenomenon. This is because when the shear stress is large, the emulsion will exhibit strong elongation, network breakage and droplet deformation, which leads to a decrease in the apparent viscosity value.

[0184] In addition, from Figure 2 (c) As can be seen, the storage modulus (G') of the emulsion loaded with roast beef flavor is higher than the loss modulus (G”), exhibiting a gel network structure dominated by elasticity. In terms of microstructure, a protein / polysaccharide complex is attached to the surface of the oil droplets in the composite Pickering emulsion, and aggregates are formed between the oil droplets, leading to an increase in the viscous modulus of the system. The emulsion system is relatively viscous, consistent with the characteristics of pseudoplastic fluids, which is consistent with the rheological results. Figure 4As shown, the characteristic aroma compounds in Example 1 exhibited high stability under heat treatment conditions, with the release of aroma compounds gradually increasing with increasing heat treatment time. When the heat treatment time increased from 5 min to 25 min, the release amounts of 2-methyltetrahydrofuran-3-one, 2-methyl-3-methylthiofuran, furfural, 2-acetylthiazole, and furfuryl methyl disulfide were 8.63%, 5.22%, 7.85%, 2.53%, and 5.24%, respectively. In the composite Pickering emulsion, 2,3,5-trimethylpyrazine showed the strongest response to heating time, with the highest release of aroma compounds as heating time increased. When the heating time reached 25 min, the retention rate of 2,3,5-trimethylpyrazine in the composite Pickering emulsion was 40.58% ± 3.95%. This may be because heating denatures the protein and polysaccharide molecules in the emulsion, forming voids or gaps. These voids can provide diffusion channels for 2,3,5-trimethylpyrazine molecules, accelerating the release rate of 2,3,5-trimethylpyrazine. In addition, as the heating time increases, the interfacial tension between oil and water gradually decreases, making it easier for 2,3,5-trimethylpyrazine molecules to diffuse from the oil phase to the aqueous phase, thus accelerating their release rate.

[0185] like Figure 5 As shown, the retention of characteristic aroma compounds in plant-based meat after adding different concentrations of the compound Pickering emulsion from Example 1 was significantly higher than that of plant-based meat with the same concentration of flavoring added. Among them, 2,3,5-trimethylpyrazine had the highest retention rate, followed by furfural and 2-methyl-3-methylthiofuran.

[0186] As shown in Table 2, adding a roasted beef flavoring compound Pickering emulsion to plant-based meat significantly reduced various textural parameters, including firmness, resulting in a softer and more tender texture. With increasing flavoring content in the emulsion, elasticity and adhesiveness increased, likely due to the excellent water retention capacity of chitosan in the compound Pickering emulsion, which helps retain moisture in the plant-based meat, making it juicier and more elastic. Simultaneously, the gel network structure formed by the compound Pickering emulsion also contributes to the elasticity of the plant-based meat, making it more juicy.

[0187] Experiments 1-13 were preliminary experiments in the research process of this invention and form the basis of this research. As the proportion of added soy protein isolate decreased, the particle size of Experiments 1-5 showed a trend of first increasing and then decreasing. The largest particle size was found in Experiment 4 at 5.47 μm, with a PDI value of 0.311, greater than 0.3, indicating that the composite Pickering emulsion exhibited polydispersity at this point. Figure 6 (b)). For example Figure 6As shown in (c), the particle size of Examples 6-9 continuously increased with longer preheating times. This is because the interactions between protein and polysaccharide molecules may change when the soy protein isolate / chitosan composite solution is heated. For example, some acidic amino acid residues of the protein may be protonated, leading to a change in their charge state. This alters the electrostatic interactions, hydrogen bonds, van der Waals forces, and other interactions within the complex, causing aggregation. The particle size of Examples 10-13 fluctuated significantly with pH changes, with Example 11 exhibiting the largest particle size. This is because the isoelectric point of soy protein isolate is around pH 4.5. When the solution pH reaches around 4.5, protein precipitation occurs, further increasing the size of the emulsion particles. Figure 6 (a)).

[0188] Compared to Examples 2-13, Example 1 exhibited the largest absolute Zeta potential value, approximately 50.76 mV, and the highest stability. Under these preparation conditions, soy protein isolate and chitosan exhibited the largest absolute potential values, thereby enhancing their affinity and interaction forces, which is beneficial for forming a stable Pickering emulsion. Figure 7 ).like Figure 7 As shown in (b), when the proportion of chitosan in the composite Pickering emulsion gradually increases, the absolute value of the Zeta potential in Experiments 1-5 first increases and then decreases. This is presumably because the amino groups on the chitosan surface cause the surface potential of the emulsion to increase with increasing chitosan content. However, with increasing heat treatment time of the SPI / CS solution, the absolute value of the potential in Experiments 6-9 does not change significantly. Figure 7 (c)). For example Figure 7 As shown in (a), the absolute value of the zeta potential of the composite Pickering emulsion first increases and then decreases with increasing pH. Potential is one of the most important indicators for screening high-quality emulsions; emulsions with high potentials are preferentially screened. After potential screening, emulsions with smaller particle sizes are preferred.

[0189] EAI refers to the ability of a protein to form an emulsion, while ESI is related to its ability to stabilize droplets during emulsification. Combining the two can analyze whether a complex can form a stable emulsion. Figure 8 As shown, the maximum EAI in Experiment 1 was 48.31m. 2 / g, ESI was 247.30 min, and the emulsion had the highest stability. In experiments 2-5, the EAI gradually increased with increasing polysaccharide ratio, while the ESI showed a trend of first increasing and then decreasing. Figure 8 (b)). For example Figure 8 As shown in (c), the EAI and ESI of Experiments 6–9 all showed a trend of first increasing and then decreasing with increasing preheating time. Figure 8As shown in (a), with the increase of pH, the EAI of experimental examples 10-13 gradually decreased, while the ESI showed a trend of first increasing and then decreasing.

[0190] The above embodiments are merely preferred embodiments of the present invention and should not be construed as limiting the scope of protection of the present invention. Any non-substantial changes and substitutions made by those skilled in the art based on the present invention shall fall within the scope of protection claimed by the present invention.

Claims

1. A method for preparing a plant-based roast beef flavor composite Pickering emulsion, characterized by, The method comprises the following steps: Step 1, weighing soybean protein isolate and chitosan; Step 2, preparing a soybean protein isolate solution: dissolving the soybean protein isolate in water to prepare a solution; Step 3, preparing a chitosan solution: dissolving the chitosan in 1% acetic acid to prepare a solution; Step 4, mixing the solutions: mixing the soybean protein isolate solution and the chitosan solution, and heating at 90°C for 8-12 min; the mass ratio of the soybean protein isolate to the chitosan in the mixed solution is 1:3; Step 5, adjusting the pH value: adjusting the pH value of the mixed solution to 3.5 after the mixed solution is cooled to room temperature; Step 6, preparing an emulsion: adding plant oil containing roast beef flavor into the mixed solution, and homogenizing, to obtain the roast beef flavor composite Pickering emulsion; the flavor components of the roast beef flavor include furfuryl methyl disulfide, 2-methyl-3-methylthiofuran, 2,3,5-trimethylpyrazine and ethyl octanoate, and the mass of the roast beef flavor accounts for 0.8%-1.2% of the mass of the roast beef flavor composite Pickering emulsion; the plant oil is in a liquid state at room temperature, and the volume of the plant oil accounts for 38%-42% of the volume of the roast beef flavor composite Pickering emulsion.

2. The method of preparing a plant-based roast beef flavor composite Pickering emulsion according to claim 1, characterized in that, Step 2, preparing a soybean protein isolate solution: dissolving the soybean protein isolate in water to prepare a solution, magnetically stirring for 4 h, and hydrating overnight at 4°C for standby; Step 3, preparing a chitosan solution: dissolving the chitosan in 1% acetic acid to prepare a solution, magnetically stirring for 4 h, and hydrating overnight at 4°C.

3. The method of preparing a plant-based roast beef flavor composite Pickering emulsion according to claim 1, characterized in that, The mass concentrations of the soybean protein isolate solution prepared in step 2 and the chitosan solution prepared in step 3 are the same.

4. The method of preparing a plant-based roast beef flavor composite Pickering emulsion according to claim 3, characterized in that, The mass concentrations of the soybean protein isolate solution prepared in step 2 and the chitosan solution prepared in step 3 are both 2%.

5. The method of preparing a plant-based roast beef flavor composite Pickering emulsion according to claim 1, characterized in that, In step 6, the plant oil is sunflower oil, and the volume of the plant oil accounts for 40% of the volume of the roast beef flavor composite Pickering emulsion.

6. The method of preparing a plant-based roast beef flavor composite Pickering emulsion according to claim 5, characterized in that, In step 6, the mass concentration of the roast beef flavor in the plant oil is 2.5%.

7. Use of the roast beef flavour composite Pickering emulsion according to any one of claims 1 to 6, characterized in that: The roast beef flavor composite Pickering emulsion is added into a plant protein semi-finished product for making plant meat, so that the final flavor addition amount reaches 1-3 mg / g, the plant protein semi-finished product is uniformly mixed, and then is placed in a mold for molding, baking, to obtain a finished plant meat.

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