Preparation method and application of BMFDS-loaded microcapsule

Abstract

The invention discloses a preparation method and application of a microcapsule loaded with BMFDS. The preparation method comprises the following steps: mixing a mucoprotein solution and a chitosan solution, and carrying out complex coacervation reaction to obtain a composite wall material solution, wherein the reaction pH value is 7-9; the mass ratio of the mucoprotein to the chitosan in the mixed solution is 3: 1-1: 3, and the total mass concentration of the mucoprotein and the chitosan is 1.0%-2.0%; the reaction temperature is 20-40 DEG C and the heating time is 40-60 minutes; the BMFDS ethanol solution is added into the composite wall material solution, the concentration of the BMFDS is 0.002-0.05 mg / g, homogenization and centrifugation are carried out, precipitates obtained through centrifugation are freeze-dried, and then the microcapsules loaded with the BMFDS are obtained. And adding the microcapsules into the semi-finished product of the plant meat product which is not subjected to heating processing, and performing baking processing to obtain the finished product of the plant meat product. After the microcapsule loaded with the BMFDS is added into a plant meat product, the loss of exogenous aroma of the plant meat can be remarkably reduced, and the flavor of the plant meat is improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of food processing, and in particular to the technical field of plant meat and related additives, and specifically relates to a preparation method of BMFDS-loaded microcapsules and application thereof. Background Art

[0002] Meat flavor is an additive with meat flavor as the main ingredient. It can improve the flavor and taste of food and is widely used in many food industries such as meat products, quick-frozen foods, convenience foods, catering ingredients and baked foods. Existing meat flavors mainly include mixed flavors and thermal reaction flavors. Basic meat aroma, characteristic meat aroma, roasted aroma, caramel aroma, onion and garlic aroma, smoky aroma and spicy aroma are the main aromas that contribute to the meat aroma. These aromas are produced by compounds such as alcohols, aldehydes, ketones, thiazoles, furans, pyrazines and sulfur-containing compounds. Plant protein meat is made from plant proteins such as soy protein, pea protein and wheat protein as the main raw materials. It is prepared through pretreatment, seasoning, bonding and molding. It has the advantages of unique flavor and taste and healthy nutrition. In recent years, it has been loved and paid attention to by more and more consumers. Therefore, the application of meat flavor in plant meat is also gradually increasing. Studies have shown that the addition of flavors can effectively improve the flavor of plant meat and make it closer to the real meat aroma.

[0003] The aroma compounds in food have low molecular weight and high volatility. They are easy to evaporate and volatilize during processing and storage, causing huge losses, and also affect the smell of the spatial environment to a certain extent. Secondly, the aroma of the flavor is easily distorted by environmental influences such as temperature, humidity, oxygen, and pH. In addition, the flavor matrix is ​​rich in nutrients, which is conducive to the growth and reproduction of microorganisms, causing the flavor to spoil, which will limit the use and preservation of the flavor.

[0004] Microcapsule technology is a micro-encapsulation protection technology that uses polymer materials to embed unstable and volatile active substances. Microcapsules are microparticles made from them. Microcapsule technology has been widely used in the food field as an important food processing technology. This technology can change the volume and state of materials, solidify them to facilitate storage and transportation; it can also improve the stability of the core material, isolate the influence of environmental factors such as temperature and light, and avoid oxidation and decomposition reactions of unstable components; prevent the volatilization of aroma compounds and control their release, control the release rate and duration of aroma compounds, and thus accurately control the release of aroma. Based on different principles, there are many technologies for preparing microcapsules, including spray drying, emulsification diffusion, complex coacervation, nanoprecipitation, layer-by-layer self-assembly, etc. Among them, the complex coacervation method has been widely used due to its mild reaction, simple preparation, good stability of the prepared product, and high encapsulation rate.

[0005] In the process of preparing microcapsules, the wall materials used are lipids, proteins and polysaccharides. At present, gum arabic, gelatin, chitosan, sodium alginate, soy protein, etc. are often used as wall materials in complex coacervation. However, in the food industry, especially in the field of flavor research and control of plant meat, there is still a technical gap in the application of microcapsules. More substances with potential for use as wall materials need to be discovered, and the preparation conditions of microcapsules need to be further optimized. Summary of the invention

[0006] In order to overcome the shortcomings of the prior art, one of the purposes of the present invention is to provide a method for preparing microcapsules loaded with bis(2-methyl-3-furanyl) disulfide (BMFDS) using mucin / chitosan complex coacervate as the wall material, so as to solve the problem of flavor dissipation of flavor compounds during the processing of plant meat products, and significantly enhance the sensory quality of plant protein meat. Another purpose of the present invention is to provide a specific application method of the microcapsule. The purpose of the present invention is achieved by the following technical solutions:

[0007] In order to solve the above technical problems, the present invention provides a method for preparing microcapsules loaded with BMFDS, comprising the following steps:

[0008] 1) Weigh mucin (MUC) and chitosan (CS);

[0009] 2) preparing a mucin solution: dissolving the mucin in water to prepare a solution;

[0010] 3) preparing chitosan solution: dissolving chitosan in 1% acetic acid aqueous solution to prepare a solution;

[0011] 4) mixing the mucin solution and the chitosan solution for a complex coagulation reaction to obtain a composite wall material solution: the pH value of the complex coagulation reaction is 7 to 9; the mass ratio of mucin to chitosan in the mixed solution is 3:1 to 1:3; the total mass concentration of mucin and chitosan is 1.0% to 2.0%; the reaction temperature after the mucin solution and the chitosan solution are mixed is 20 to 40° C., and the heating time is 40 to 60 min;

[0012] 5) Preparation of microcapsules loaded with bis(2-methyl-3-furanyl) disulfide (BMFDS): Adding a BMFDS ethanol solution to a composite wall material solution, wherein the concentration of BMFDS in the composite wall material solution is 0.002 to 0.05 mg / g, homogenizing, centrifuging at 10,000 rpm for 15 min at 4°C, discarding the supernatant, and freeze-drying the precipitate (polymer) obtained by centrifugation to obtain the BMFDS-loaded microcapsules.

[0013] A further scheme, step 2), prepare a mucin solution: dissolve mucin in water to form a solution, stir magnetically for 4 hours, and hydrate at 4°C overnight for use; step 3), prepare a chitosan solution: dissolve chitosan in 1% acetic acid aqueous solution to form a solution, stir magnetically for 4 hours, and hydrate at 4°C overnight; the mass concentration of the mucin solution prepared in step 2) and the chitosan solution prepared in step 3) are the same.

[0014] Furthermore, in step 4), the pH value of the complex coagulation reaction is 7.

[0015] In step 4), the mass ratio of mucin to chitosan in the mixed solution is 1:3.

[0016] In step 4), the total mass concentration of mucin and chitosan in the mixed solution is 2.0%.

[0017] In step 4), the reaction temperature after mixing mucin and chitosan is 30°C.

[0018] In step 4), the mucin solution and the chitosan solution are mixed and heated for 40 minutes.

[0019] Furthermore, in step 5), the concentration of BMFDS in the composite wall material solution is 0.01 mg / g.

[0020] The application of the BMFDS-loaded microcapsules is to add the microcapsules to a semi-finished plant meat product that has not been heated, and then obtain the finished plant meat product after baking.

[0021] A further solution is to add the microcapsules to an aqueous solution of soy tissue protein and fibrous protein that is continuously stirred at 0-4°C for 12 hours so that the final flavor addition amount reaches 0.01 mg / g, the mass ratio of fibrous protein to soy tissue protein is 2:8, and the mixture is stirred and placed in a mold for forming. The baking temperature is 160-200°C and the baking time is 12-16 minutes to obtain the finished plant meat product.

[0022] Beneficial effects of the present invention:

[0023] (1) In the BMFDS-loaded microcapsules of the present invention, mucin and chitosan are used for complex coagulation, and BMFDS is embedded. Mucin can form a complex by non-covalent interaction (electrostatic interaction, hydrogen bond and hydrophobic interaction, etc.) with chitosan. By adjusting the ratio of mucin / chitosan solution, the total concentration of wall material, pH, reaction time and reaction temperature, microcapsules with the ability to significantly improve the stability of aroma compounds are prepared.

[0024] (2) The BMFDS-loaded microcapsules described in the present invention can significantly reduce the loss of exogenous aroma of plant meat and enhance the flavor of plant meat after being added to plant meat products. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0026] Figure 1 The equilibrium phase turbidity and condensed phase yield measured in the test examples 1-1 to 1-5, the effects of pH (A), MUC / CS ratio (B), total wall material concentration (C), reaction temperature (D), and reaction time (E) on the complex coagulation reaction of MUC and CS. Different lowercase letters in the figure indicate significant differences (P<0.05).

[0027] Figure 2 It is the infrared spectra of MUC, CS and the MUC-CS complex coacervate prepared in the MUC / CS ratio of 1:3 in Experimental Example 1-2.

[0028] Figure 3 It is the DSC thermal analysis diagram of MUC, CS and the MUC-CS complex coacervate prepared in the MUC / CS ratio of 1:3 in Experimental Example 1-2.

[0029] Figure 4 These are scanning electron microscope images of MUC (A), CS (B), and the MUC-CS complex coacervate prepared in the MUC / CS ratio of 1:3 in Experimental Example 1-2 (C).

[0030] Figure 5 The effect of adding MUC-CS-BMFDS microcapsules and SPI-CS-BMFDS microcapsules prepared in Example 1-2 and Comparative Example 2-2 respectively during the processing of plant meat on the flavor of plant meat at different baking temperatures (A) and different baking times (B). Different lowercase letters in the figure indicate significant differences (P<0.05). DETAILED DESCRIPTION

[0031] Test Example 1-1

[0032] This test example provides a method for preparing a composite coacervate of mucin and chitosan, and the preparation method comprises the following steps:

[0033] (1) Weigh a certain amount of mucin and chitosan;

[0034] (2) Preparation of mucin solution: dissolve mucin in water to prepare a solution with a mass concentration of 2%, stir magnetically for 4 h, and store at 4° C. overnight;

[0035] (3) Preparation of chitosan solution: Dissolve chitosan in 1% acetic acid aqueous solution to make a 2% solution, stir magnetically for 4 h, and store at 4°C overnight;

[0036] (4) Mixing the solutions to obtain a composite wall material solution: fixing the mass ratio of MUC and CS at 1:1 and the total mass concentration of the wall materials (mucin and chitosan) at 2%, the two solutions were mixed in a 30°C water bath, and the pH value of the system was adjusted to 5, 6, 7, 8, and 9 with HCl and NaOH, and stirring was continued for 40 min.

[0037] (5) Centrifuge at 10,000 rpm for 15 min at 4°C, measure the turbidity of the supernatant, and freeze-dry the complex to obtain the MUC-CS complex.

[0038] The results of equilibrium phase turbidity and coacervate phase yield during the preparation of MUC-CS complex are shown in Figure 1 As shown in A.

[0039] The mucin described in this example was purchased from Sigma-Aldrich Company, USA, with the product model number M2378; chitosan was purchased from Shanghai Yuanye Biotechnology Co., Ltd., with the product model number S11064.

[0040] Test Example 1-2

[0041] This test example provides a method for preparing a composite coacervate of mucin and chitosan. The raw materials used are the same as those in Test Example 1-1. The difference between the preparation method and Test Example 1-1 is that:

[0042] In step (4), the total mass concentration of the fixed wall material is 2%, and the mass ratios of MUC and CS are 5:1, 3:1, 1:1, 1:3, and 1:5, respectively. The two solutions are mixed in a water bath at 30°C, and the pH value of the system is adjusted to 7 with HCl and NaOH, and stirring is continued for 40 minutes.

[0043] The results of equilibrium phase turbidity and coacervate phase yield during the preparation of MUC-CS complex are shown in Figure 1 As shown in B.

[0044] Test Example 1-3

[0045] This test example provides a method for preparing a composite coacervate of mucin and chitosan. The raw materials used are the same as those in Test Example 1-1. The difference between the preparation method and Test Example 1-1 is that:

[0046] In step (4), the mass ratio of MUC to CS was selected to be 1:1, and solutions with total wall material concentrations of 1.0%, 1.5%, 2.0%, 2.5%, and 3.0% were prepared respectively. The two solutions were mixed in a 30° C. water bath, and the pH value of the system was adjusted to 7 with HCl and NaOH, and stirring was continued for 40 min.

[0047] The results of equilibrium phase turbidity and coacervate phase yield during the preparation of MUC-CS complex are shown in Figure 1 As shown in C.

[0048] Test Examples 1-4

[0049] This test example provides a method for preparing a composite coacervate of mucin and chitosan. The raw materials used are the same as those in Test Example 1-1. The difference between the preparation method and Test Example 1-1 is that:

[0050] In step (4), the mass ratio of MUC and CS was fixed at 1:1, the total mass concentration of the wall material was 2%, and the two solutions were mixed in a water bath at 20°C, 30°C, 40°C, 50°C, and 60°C, respectively. The pH value of the system was adjusted to 7 with HCl and NaOH, and stirring was continued for 40 minutes.

[0051] The results of equilibrium phase turbidity and coacervate phase yield during the preparation of MUC-CS complex are shown in Figure 1 As shown in D.

[0052] Test Examples 1-5

[0053] This test example provides a method for preparing a composite coacervate of mucin and chitosan. The raw materials used are the same as those in Test Example 1-1. The difference between the preparation method and Test Example 1-1 is that:

[0054] In step (4), the mass ratio of MUC and CS was fixed at 1:1, the total mass concentration of the wall material was 2%, the two solutions were mixed in a water bath at 30°C, the pH value of the system was adjusted to 7 with HCl and NaOH, and stirring was continued for 20 min, 30 min, 40 min, 50 min, and 60 min.

[0055] The results of equilibrium phase turbidity and coacervate phase yield during the preparation of MUC-CS complex are shown in Figure 1 As shown in E.

[0056] Experiment 1: Optimization of complex coagulation conditions

[0057] The experimental results are as follows Figure 1AE described; the results show that when the pH increases from 5.0 to 9.0, the turbidity of the equilibrium phase first decreases and then increases, and the yield of the coacervate phase first increases and then decreases. When the pH of the system is 7.0, the turbidity of the equilibrium phase is the lowest and the yield of the coacervate phase is the highest. The positive and negative charge density of the biopolymer reaches a stoichiometric balance, and the molecular structure of the complex polymer generated under this pH condition is stable. When the ratio of MUC / CS gradually decreases, the turbidity first decreases and then increases, and the yield of the coacervate phase first increases and then decreases. When the ratio is 1:3, the turbidity is the lowest and the yield of the coacervate is the highest. This is because when the anions and cations are not in the optimal mixing ratio, one component exists in excess and the other component is insufficient, resulting in excessive polymer molecules in the equilibrium phase. When the total mass concentration of MUC and CS is 2%, the turbidity of the equilibrium phase is the lowest and the yield of the coacervate phase is the highest. At the appropriate total wall material mass concentration, the expansion of the main chain of the macromolecule is small and more flexible, and the charge sites are more likely to interact and form complex coacervate. At 30°C, the turbidity of the equilibrium phase is the lowest and the yield of the coacervate phase is the highest. In the process of complex coagulation, in addition to electrostatic interactions, there are other interactions. When the temperature is low, more hydrogen bonds will be generated during the complex coagulation process, while when the temperature is high, the high energy of the molecules hinders the formation of hydrogen bonds, and at high temperatures, proteins and polysaccharides will swell and produce adhesion. At 40 minutes, the turbidity of the equilibrium phase is the lowest and the yield of the coagulation phase is the highest, indicating that MUC and CS have almost completely reacted after 40 minutes of reaction.

[0058] Experiment 2: IR spectrum analysis, DSC analysis, and SEM morphology of MUC-CS complex

[0059] Appropriate amounts of MUC, CS, and MUC-CS freeze-dried powder (samples obtained by optimizing the complex coagulation conditions, equivalent to the mass ratio of MUC to CS in Experimental Example 1-2 of 1:3) were mixed with KBr at a ratio of 1:100, ground in a mortar, and then pressed into tablets using a tablet press. The results were analyzed using an Avater.370 Fourier transform infrared spectrometer at 4000-400 -1 The sample was scanned within the scanning range, with KBr flakes as the background, and the spectrum was obtained after an average of 32 scans.

[0060] Accurately weigh 5 mg of MUC, CS, and MUC-CS complex samples (samples obtained by optimizing complex coagulation conditions) and seal them in an aluminum pan. Use a differential scanning calorimeter to scan the heat flow changes of the samples in the range of 20-220°C at a heating rate of 10°C / min.

[0061] Weigh appropriate amounts of MUC, CS, and MUC-CS composite samples (samples obtained by optimizing composite coagulation conditions), fix the samples on the sample stage with conductive tape, and after gold spraying, take photos with a scanning electron microscope to observe the microscopic morphology of the samples.

[0062] Depend on Figure 2It can be seen that the infrared spectrum of MUC-CS has a characteristic absorption peak wavelength of -COOR group shifted to 1155cm-1 compared with that of MUC. -1 , compared to CS, 1597cm -1 -NH 3+ The absorption peak of MUC and CS disappears, proving that there is electrostatic interaction between MUC and CS, which leads to complex coagulation. The spectral curves of the remaining positions in MUC-CS are approximately the superposition of the infrared spectral curves of MUC and CS. -1 A broader peak appeared, which was due to the overlap of -OH in its structure, and after complex coagulation, the absorption peak intensity and wavelength of -OH changed, which indicated that there was still hydrogen bonding between MUC and CS.

[0063] Depend on Figure 3 It can be seen that the peak temperature of MUC is 145℃, and the peak temperature of CS is 128℃. This is because the structures of the two are different, which also shows that MUC has higher stability. The peak temperature of the product of MUC and CS complex coagulation is 141℃, and the transition temperature is higher than CS, indicating that a more stable structure is formed between the two. The addition of protein enhances the thermal stability of CS.

[0064] Depend on Figure 4 It can be seen that MUC is an irregular aggregate, CS is a flat block structure, and the product obtained by the complex coagulation of MUC and CS is a loose and porous network structure, indicating that the negatively charged MUC is attached to the positively charged CS surface through electrostatic interaction to form a complex with a new structure, but MUC and CS are uniformly cross-linked in the liquid and have not yet embedded the core material, and finally a network structure is formed.

[0065] Example 1-1

[0066] A method for preparing BMFDS-loaded microcapsules comprises the following steps:

[0067] 1) Weigh a certain amount of mucin (MUC) and chitosan (CS);

[0068] 2) Preparation of mucin solution: dissolve mucin in water to prepare a solution with a mass concentration of 2%, stir magnetically for 4 hours, and store at 4°C overnight;

[0069] 3) Preparation of chitosan solution: dissolve chitosan in 1% acetic acid aqueous solution to make a solution with a mass concentration of 2%, stir magnetically for 4 hours, and store at 4°C overnight;

[0070] 4) Then, the MUC solution and the CS solution were mixed to obtain a composite wall material solution: the mass ratio of MUC and CS was fixed at 1:3, the total mass concentration of the wall materials (mucin and chitosan) was 2%, the two solutions were mixed in a 30°C water bath, the pH value of the system was adjusted to 7 with HCl and NaOH, and stirring was continued for 40 minutes.

[0071] 5) Preparation of BMFDS-loaded microcapsules: Take an appropriate amount of BMFDS and dissolve it in anhydrous ethanol to obtain a BMFDS ethanol solution; take an appropriate amount of BMFDS ethanol solution and add it to the composite wall material solution, wherein the mass concentration of BMFDS in the composite wall material solution is 0.002 mg / g; centrifuge at 10000 r / min for 15 min at 4°C, and discard the supernatant. The precipitate obtained by centrifugation is freeze-dried to obtain BMFDS microcapsules.

[0072] Example 1-2

[0073] This embodiment makes the following changes relative to embodiment 1-1:

[0074] Take an appropriate amount of BMFDS ethanol solution and add it to the composite wall material solution, the mass concentration of BMFDS in the composite wall material solution is 0.01 mg / g. The rest is the same as Example 1-1.

[0075] Examples 1-3

[0076] This embodiment makes the following changes relative to embodiment 1-1:

[0077] Take an appropriate amount of BMFDS ethanol solution and add it to the composite wall material solution, the mass concentration of BMFDS in the composite wall material solution is 0.05 mg / g. The rest is the same as Example 1-1.

[0078] Comparative Example 1-1

[0079] This comparative example is modified as follows relative to Example 1-1:

[0080] Take an appropriate amount of BMFDS ethanol solution and add it to the composite wall material solution, the concentration of BMFDS in the composite wall material solution is 0.25 mg / g. The rest is the same as Example 1-1.

[0081] Comparative Example 2-1:

[0082] When the concentration of BMFDS in the composite solution was 0.002 mg / g, SPI / CS complex coacervates were used to prepare BMFDS-loaded microcapsules.

[0083] The wall material is composed of soy protein isolate (SPI) and chitosan (CS), and the specific steps are as follows:

[0084] 1) Weigh a certain amount of soy protein isolate and chitosan;

[0085] 2) Preparation of soy protein isolate solution: dissolve soy protein isolate in water to prepare a solution with a mass concentration of 2.67%, stir magnetically for 4 hours, and keep at 4° C. overnight;

[0086] 3) Preparation of chitosan solution: dissolve chitosan in 1% acetic acid aqueous solution to prepare a solution with a mass concentration of 1%, stir magnetically for 4 hours, and store at 4°C overnight;

[0087] 4) The solutions were then mixed to obtain a composite wall material solution: the mass ratio of SPI and CS was fixed at 4:1, the total concentration of wall materials (SPI and CS) was 2%, the two solutions were mixed in a water bath at 25°C, the pH value of the system was adjusted to 6.5 with HCl and NaOH, and stirring was continued for 40 minutes.

[0088] The optimal conditions for complex coacervation of SPI and CS were determined according to the reference Huang G, Sun Y, Xiao J, et al. Complex coacervation of soybean protein isolate and chitosan[J]. Food Chemistry, 2012, 135(2): 534-539.

[0089] 5) Preparation of BMFDS-loaded microcapsules: dissolving an appropriate amount of BMFDS in anhydrous ethanol to obtain a BMFDS ethanol solution; adding an appropriate amount of the BMFDS ethanol solution to the composite wall material solution, wherein the concentration of BMFDS in the composite wall material solution is 0.002 mg / g; centrifuging at 10,000 r / min for 15 min at 4°C, discarding the supernatant, and freeze-drying the precipitate obtained by centrifugation to obtain SPI-CS-BMFDS microcapsules.

[0090] Comparative Example 2-2:

[0091] This comparative example is modified as follows relative to comparative example 2-1:

[0092] Take an appropriate amount of BMFDS ethanol solution and add it to the composite wall material solution, the concentration of BMFDS in the composite wall material solution is 0.01 mg / g. The rest is the same as Comparative Example 2-1.

[0093] Comparative Example 2-3:

[0094] This comparative example is modified as follows relative to comparative example 2-1:

[0095] Take an appropriate amount of BMFDS ethanol solution and add it to the composite wall material solution, the concentration of BMFDS in the composite wall material solution is 0.05 mg / g. The rest is the same as Comparative Example 2-1.

[0096] Comparative Examples 2-4:

[0097] This comparative example is modified as follows relative to comparative example 2-1:

[0098] Take an appropriate amount of BMFDS ethanol solution and add it to the composite wall material solution, the concentration of BMFDS in the composite wall material solution is 0.25 mg / g. The rest is the same as that of Comparative Example 2-1.

[0099] Experiment 3: Determination of the embedding efficiency of BMFDS in microcapsules

[0100] Drawing of BMFDS standard curve: Using ultraviolet scanning spectrum at 200-700nm, the characteristic absorption peak of BMFDS ethanol solution is 263nm, and then the absorbance values ​​of BMFDS ethanol solutions of different concentrations are measured to obtain the standard curve of BMFDS. The standard curve is y=24.788x-0.0083, R 2 =0.9999.

[0101] Take the prepared microcapsule powder of Examples 1-1 to 1-3 and Comparative Examples 1-1 and Comparative Examples 2-1 to 2-4 and mix them with ethanol, collect the supernatant by centrifugation, measure the BMFDS absorbance at a wavelength of 263nm, and calculate the free BMFDS content. Take the same amount of microcapsule powder and mix it with ethanol, ultrasonicate for 30 minutes at a temperature of 60°C and a frequency of 40kHz to extract the embedded BMFDS, collect the supernatant by centrifugation, measure the absorbance at the same wavelength, and calculate the total BMFDS content according to the standard curve of BMFDS. The results are shown in Table 1 below.

[0102] The BMFDS embedding efficiency calculation is as follows:

[0103]

[0104] Note: The total amount of BMFDS refers to the total mass of BMFDS in the composite solution, and the free BMFDS refers to the mass of BMFDS attached to the microcapsule powder. The difference between them is the mass of BMFDS embedded in the microcapsules.

[0105] Table 1

[0106]

[0107] With the increase of BMFDS content, the embedding rate of MUC-CS microcapsules first increased and then decreased. When the BMFDS content was 0.01 mg / g, the embedding rate reached 87.69%. The embedding rate of SPI-CS microcapsules for BMFDS decreased with the increase of BMFDS content, and the highest embedding rate was 49.29%. By comparison, it was found that MUC and CS complex coagulation could effectively embed BMFDS, and its embedding effect was better than that of SPI and CS complex coagulation.

[0108] Experiment 4: Application of BMFDS microcapsules in plant-based meat

[0109] The preparation method of plant meat is based on the experimental method optimized by the research group in the early stage. The fibrous protein and soy textured protein are soaked in water at a mass ratio of 2:8 and stirred for 12 hours for rehydration. BMFDS stock solution, MUC-CS-BMFDS microcapsules, and SPI-CS-BMFDS microcapsules are added to the rehydrated protein and stirred evenly. After mixing, it is formed through a mold to obtain a meat patty with a thickness of 1.5 cm and a radius of 5 cm. Plant meat patties were prepared at different baking temperatures (flavor addition amount of 0.01 mg / g, baking time of 12 min, baking temperature of 160 ° C, 180 ° C, 200 ° C) and different baking times (flavor addition amount of 0.01 mg / g, baking temperature of 180 ° C, baking time of 12 min, 14 min, 16 min).

[0110] Extract aroma compounds from plant patties. Accurately weigh 2.0g of sample and seal it in a headspace vial. After equilibration at 55℃ for 15min, use SPME fiber to adsorb volatile BMFDS in the headspace vial at 55℃ for 40min. Then desorb at 250℃ for 5min to release volatile compounds.

[0111] The preparation method of plant meat is based on Li Yan, Zeng Xiangquan, Du Wenbin, et al. Effects of different vegetable oils on the flavor and sensory properties of plant meat[J]. Journal of Food Science and Technology, 2022, 40(02): 31-44.

[0112] The extraction method of aroma compounds in plant patties was based on the literature: Li X, Zeng X, Xi Y, et al. Effects of non-covalent interactions between pectin and volatile compounds on the flavor release of tomato paste[J]. Food Hydrocolloids, 2022, 133: 107886. and some modifications were made.

[0113] The effects of different baking temperatures and different baking times on the flavor of plant meat are as follows: Figure 5 (AB) shown.

[0114] according to Figure 5A. As the baking temperature increased from 160°C to 200°C, the BMFDS content in the plant meat decreased significantly. In the control group, the aroma compounds decreased by 41.03%. The BMFDS content in the MUC-CS and SPI-CS groups was lower than that in the control group (the control group used BMFDS solution, and the initial concentration of BMFDS in the three groups was 0.01 mg / g. The encapsulation rates of BMFDS in the MUC-CS and SPI-CS groups were 87.69% and 40.5%, respectively). However, the aroma loss during the baking temperature change was only 19.32%, and the aroma loss in the SPI-CS group was only 21.52%. This shows that encapsulation can protect the aroma compounds, reduce the aroma loss during processing, and have a better sustained release effect.

[0115] according to Figure 5 B. As the baking time increased from 12 min to 14 min, the BMFDS content in the plant meat decreased significantly. In the control group, the aroma compounds decreased by 42.45%. The aroma loss of BMFDS content in the MUC-CS and SPI-CS groups during the extended baking time was only 20.03%, and the aroma loss in the SPI-CS group was only 24.53%, indicating that the aroma loss in the plant meat can be effectively reduced after BMFDS is embedded, and MUC not only has a higher embedding rate for BMFDS but also has a better protection effect than SPI.

[0116] The above experiment mainly compares the retention of BMFDS in vegetable meat as the baking temperature increases. As can be seen from the above, the aroma loss of the essence after embedding during the temperature change process is greatly reduced compared with the control group, which shows that embedding can protect the aroma compounds, reduce the aroma loss during processing, and have a better sustained release effect.

[0117] In summary, when pH value was 7.0, MUC / CS ratio was 1:3, total wall material concentration was 2%, temperature was 30℃, and reaction time was 40min, mucin and chitosan had the best coagulation state. MUC and CS mainly formed complex coacervates through electrostatic interaction. The complex was a gel network structure and increased the thermal stability of CS. When the BMFDS content was 0.01mg / g, the highest embedding rate was 87.69%, while the embedding effect of SPI and CS complex coacervation on BMFDS was significantly weaker than that of MUC and CS complex coacervation. In the processing of plant meat, both baking temperature and baking time will significantly affect the content of aroma compounds in plant meat. With the increase of baking temperature and the extension of baking time, BMFDS will have different degrees of loss, but the embedding of BMFDS can effectively reduce the aroma loss in plant meat, and the protection effect of MUC and CS complex coacervation on BMFDS is better than that of SPI.

[0118] Finally, it should be noted that the above is only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred arrangement scheme, a person skilled in the art should understand that the technical solution of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solution of the present invention.

Claims

1. A method for preparing BMFDS-loaded microcapsules, characterized in that: The following steps are involved: 1) Weigh mucin and chitosan; 2) preparing a mucin solution: dissolving the mucin in water to prepare a solution; 3) preparing chitosan solution: dissolving chitosan in 1% acetic acid aqueous solution to prepare a solution; 4) mixing the mucin solution and the chitosan solution for a complex coagulation reaction to obtain a composite wall material solution: the pH value of the complex coagulation reaction is 7 to 9; the mass ratio of mucin to chitosan in the mixed solution is 3:1 to 1:3, and the total mass concentration of mucin and chitosan is 1.0% to 2.0%; the reaction temperature after the mucin solution and the chitosan solution are mixed is 20 to 40° C., and the heating time is 40 to 60 min; 5) Preparation of microcapsules loaded with bis(2-methyl-3-furanyl) disulfide BMFDS: adding a BMFDS ethanol solution to a composite wall material solution, wherein the concentration of BMFDS in the composite wall material solution is 0.002 to 0.05 mg / g, homogenizing, centrifuging at 10,000 rpm for 15 min at 4°C, discarding the supernatant, and freeze-drying the precipitate obtained by centrifugation to obtain the BMFDS-loaded microcapsules.

2. The method for preparing BMFDS-loaded microcapsules according to claim 1, characterized in that: Step 2), preparing a mucin solution: dissolving mucin in water to form a solution, magnetically stirring for 4 hours, and hydrating at 4°C overnight for use; Step 3), preparing a chitosan solution: dissolving chitosan in 1% acetic acid aqueous solution to form a solution, magnetically stirring for 4 hours, and hydrating at 4°C overnight; the mass concentration of the mucin solution prepared in step 2) and the chitosan solution prepared in step 3) are the same.

3. The method for preparing BMFDS-loaded microcapsules according to claim 1, characterized in that: In step 4), the pH value of the complex coacervation reaction is 7.

4. The method for preparing BMFDS-loaded microcapsules according to claim 1, characterized in that: In step 4), the mass ratio of mucin to chitosan in the mixed solution is 1:

3.

5. The method for preparing BMFDS-loaded microcapsules according to claim 1, characterized in that: In step 4), the total mass concentration of mucin and chitosan in the mixed solution is 2.0%.

6. The method for preparing BMFDS-loaded microcapsules according to claim 1, characterized in that: In step 4), the reaction temperature after mixing mucin and chitosan is 30°C.

7. The method for preparing BMFDS-loaded microcapsules according to claim 1, characterized in that: In step 4), the mucin solution and the chitosan solution are mixed and heated for 40 minutes.

8. The method for preparing BMFDS-loaded microcapsules according to claim 1, characterized in that: In step 5), the concentration of BMFDS in the composite wall material solution is 0.01 mg / g.

9. The use of the BMFDS-loaded microcapsules according to any one of claims 1 to 8, characterized in that: The microcapsules are added to a semi-finished plant meat product that has not been heated, and the finished plant meat product is obtained after baking.

10. The use of the BMFDS-loaded microcapsules according to claim 9, characterized in that: The microcapsules are added to an aqueous solution of soybean tissue protein and fibrous protein which is continuously stirred at 0-4°C for 12 hours so that the final BMFDS addition amount reaches 0.01 mg / g, and the mass ratio of fibrous protein to soybean tissue protein is 2:

8. After stirring and mixing, the mixture is placed in a mold for forming. The baking temperature is 160-200°C and the baking time is 12-16 minutes to obtain a finished plant meat product.

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