Method for regulating the gel strength and water holding capacity of pea protein isolate based on acoustic resonance technology

Abstract

The present invention relates to the technical field of plant protein modification and processing, and provides a method for regulating the gel strength and water holding capacity of pea protein isolate based on acoustic resonance technology, wherein a certain mass of powdered pea protein isolate is weighed and packaged, and the packaged pea protein isolates are respectively placed in mixing containers of acoustic resonance, and modified pea protein is obtained by acoustic resonance treatment, and finally the modified pea protein is prepared into a heat-induced gel. The method for regulating the gel strength and water holding capacity of pea protein isolate based on acoustic resonance technology of the present invention improves its gel properties by controlling the acoustic resonance treatment of pea protein isolate for different lengths, and obtains a pea protein product that can meet the needs of food processing, so as to develop its application value in more suitable special groups of people.

Description

Technical Field

[0001] The invention relates to the technical field of plant protein modification and processing, and in particular to a method for regulating the strength and water holding capacity of pea protein isolate gel based on acoustic resonance technology. Background Art

[0002] As people continue to pursue a healthy, green and safe diet, the choice of protein intake is increasingly tending towards low-fat, low-calorie plant proteins. Among plant-based proteins, pea protein has attracted much attention due to its low allergenicity, non-GMO characteristics, high antioxidant, high nutritional value and sustainable source. In recent years, the deep processing of peas has made certain progress, and people expect to use pea protein isolate to replace fat or soy protein in new food processing. However, compared with soy protein, the gel performance of natural pea protein is not ideal, which limits its use as a substitute for soy protein and also affects its large-scale application in the food industry.

[0003] Resonant Acoustic Mixing (RAM), also known as acoustic resonance mixing technology, is a new hybrid technology that has emerged in recent years based on the coupling of macroscopic vibration mixing and microscopic acoustic field mixing. It uses the resonance of a mechanical vibration system to generate high-intensity vibrations, which can excite low-frequency (about 60Hz) and high-acceleration (0-100g, g=9.8m·s -2 ) Under the stimulation of acoustic waves, the purpose of uniform dispersion of materials is achieved, which has the advantages of good mixing uniformity, good material dispersion and high crushing efficiency, and is also economical, green and safe. At present, acoustic resonance technology has been widely used in chemical, energy, medicine and other fields, but its application in the food field needs further research. Summary of the invention

[0004] The purpose of the present invention is to address the deficiencies of the prior art and propose a method for regulating the gel strength and water holding capacity of pea protein isolate based on acoustic resonance technology. The spatial structure of the pea protein isolate is adjusted by acoustic resonance treatment of different durations to effectively improve and enhance the gelling properties of the pea protein isolate, thereby obtaining a pea protein product that can meet the dietary needs of special groups of people and improving its application value in food.

[0005] The objective of the present invention is achieved through the following technical solutions:

[0006] A method for regulating the strength and water holding capacity of pea protein isolate gel based on acoustic resonance technology, comprising the following steps:

[0007] Step 1: Weigh a certain amount of powdered pea protein isolate for packaging;

[0008] Step 2: The packaged pea protein isolates are placed in acoustic resonance mixing containers respectively, and subjected to acoustic resonance treatment to obtain modified pea protein.

[0009] Step 3: The modified pea protein obtained by the treatment in step 2 is prepared into a heat-induced gel.

[0010] The raw material pea protein isolate of the present invention is affected by its own structure and has poor gel properties. By subjecting the pea protein isolate to acoustic resonance treatment, the pea protein isolate structure is induced to stretch, so as to adjust the spatial structure of the pea protein isolate and expose hidden active sites, which will prompt the pea protein isolate to exhibit more ideal gel properties. Specifically, during the acoustic resonance treatment process: 1) the field shear force can enhance the macroscopic vibration and microscopic acoustic flow mixing coupling inside the protein molecule, the rearrangement of the interaction between protein molecules and within the molecule, and then produce a new conformation; 2) the protein interacts with the medium and moves rapidly, the protein structure unfolds and exposes more active sites. Therefore, the gel properties of the modified pea protein isolate are improved.

[0011] Furthermore, the packaging process of the pea protein isolate in step 1 is carried out at 20-25°C.

[0012] Furthermore, the acoustic resonance treatment process of the pea protein isolate in step 2 is specifically as follows:

[0013] Step 2-1: Place the packaged pea protein isolate into acoustic resonance mixing containers respectively;

[0014] Step 2-2: Add an appropriate amount of white pickaxe beads to the mixing container as a medium to assist in protein fragmentation;

[0015] Step 2-3: Set and adjust the operating parameters of the acoustic resonance instrument and process the sample;

[0016] Step 2-4: After the acoustic resonance treatment is completed, the modified protein sample is quickly collected and sealed in a desiccator for storage.

[0017] Furthermore, the diameter of the white pick bead in step 2-2 is 2 mm.

[0018] Furthermore, in step 2-3, the sample is processed at 15-20°C.

[0019] Furthermore, the operating parameters of the acoustic resonance instrument in step 2-3 are as follows: the processing frequency is 55-65 Hz, the processing amplitude is 30-40%, the processing acceleration is 65.000-75.000 g, and the processing time is within 30 min.

[0020] Furthermore, the processing time of the acoustic resonance instrument is preferably 20 minutes.

[0021] Furthermore, the process of preparing the modified pea protein into a heat-induced gel in step 3 is specifically as follows:

[0022] Step 3-1: preparing a modified pea protein solution of a certain concentration and ionic strength, and magnetically stirring to ensure that the modified pea protein is fully dissolved;

[0023] Step 3-2: Weigh a certain amount of the modified pea protein solution and place it in a glass container with a stopper, and remove the bubbles on the surface;

[0024] Step 3-3: Place the modified pea protein solution in a constant temperature water bath and heat it for a certain period of time. After heating, quickly cool it in an ice bath and then place it in a 4°C refrigerator.

[0025] Furthermore, in step 3-1, the concentration of the modified pea protein solution is 16-20 mg / mL, and the ionic strength is 0-0.4 mol / L (NaCl).

[0026] Furthermore, the magnetic stirring time of the modified pea protein solution in step 3-1 is 30-60 min.

[0027] Furthermore, in step 3-3, the water bath heating time is 15-20 minutes, and the heating temperature is 80-95°C.

[0028] Furthermore, in step 3-3, the time for rapidly cooling the modified pea protein solution in the ice bath is 20-40 minutes.

[0029] Furthermore, the modified pea protein solution after heating and cooling in step 3-3 is placed in a 4° C. refrigerator for 12-24 hours.

[0030] The beneficial effects of the method for regulating the gel strength and water holding capacity of pea protein isolate based on acoustic resonance technology provided by the present invention are as follows:

[0031] The present invention processes pea protein isolate by acoustic resonance, realizes low-frequency, high-acceleration vertical vibration in the container under the condition of small input energy, generates a uniform shear force field, makes the protein move rapidly, and then adjusts the overall spatial conformation and particle aggregation of the protein; when not processed by acoustic resonance, the pea protein isolate structure is relatively aggregated, and the heat-induced gel strength formed at this time is relatively high, but the water holding capacity is very poor, the gel structure is loose and the surface is not smooth; the natural pea protein isolate is modified by acoustic resonance technology, which can effectively adjust the particle size and spatial structure of the protein, promote the protein structure to stretch and expose more active groups, and form a uniform and dense three-dimensional mesh structure of the gel. Among them, when the 20min acoustic resonance treatment is adopted, the water holding capacity of the protein gel is the highest and the texture is the most delicate, and the developed food is more suitable for special people to eat. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 The present invention is a process and functional characteristic analysis flow chart of the method for regulating the gel strength and water holding capacity of pea protein isolate based on acoustic resonance technology;

[0033] Figure 2 This is a histogram of the gel strength of the pea protein isolate heat-induced gel after the acoustic resonance treatment in Comparative Example 1 and Examples 1-5 of the present invention;

[0034] Figure 3 This is a bar graph of the water holding capacity of the heat-induced gel of pea protein isolate after acoustic resonance treatment in Comparative Example 1 and Examples 1-5 of the present invention;

[0035] Figure 4 It is a real picture of the common morphology of the heat-induced gel of pea protein isolate after the acoustic resonance treatment in Comparative Example 1 and Examples 1-5 of the present invention;

[0036] Figure 5 The microscopic morphology of the heat-induced gel of pea protein isolate after acoustic resonance treatment in Comparative Example 1 and Examples 1-5 of the present invention.

[0037] in, Figure 2-Figure 3 Different lowercase letters (ae) represent significant differences (P<0.05). DETAILED DESCRIPTION

[0038] The present invention is further described below in conjunction with the accompanying drawings and embodiments, but is not intended to limit the protection scope of the present invention.

[0039] Unless otherwise specified, the raw materials used in the present invention can be purchased from the market or are commonly used in the art. Unless otherwise specified, the methods in the following embodiments are all conventional methods in the art.

[0040] like Figure 1 As shown, the present invention provides a method for regulating the strength and water holding capacity of pea protein isolate gel based on acoustic resonance technology, comprising the following steps:

[0041] Step 1: Weigh and package the powdered pea protein isolate according to a certain mass at 20-25°C, and store it in a dry environment until processing.

[0042] Step 2: subjecting the packaged pea protein isolate to an acoustic resonance treatment, specifically comprising the following steps:

[0043] Step 2-1: Add the packaged pea protein isolate powder into stainless steel sample tanks respectively; wherein the mass of the protein sample added is 30-60g, and the capacity of the sample tank is 500mL.

[0044] Step 2-2: Add white beads of appropriate mass into the sample jar as a medium to assist in protein fragmentation; wherein the diameter of the beads is 2 mm.

[0045] Step 2-3: Start processing the sample in an environment of 15-20°C, set and adjust the operating parameters of the acoustic resonance instrument; wherein the acoustic resonance processing frequency is set to 55-65Hz, the processing amplitude is 30-40%, the processing acceleration is 65.000-75.000g, and the processing time is within 30min.

[0046] Step 2-4: After the acoustic resonance treatment is completed, the modified protein sample is quickly collected and sealed in a desiccator for storage.

[0047] Step 3: The modified pea protein obtained by the treatment in step 2 is prepared into a heat-induced gel, and the specific process includes the following steps:

[0048] Step 3-1: prepare a modified pea protein solution with a concentration of 16-20 mg / mL and an ionic strength of 0-0.4 mol / L (NaCl), and stir magnetically for 30-60 min to ensure that the modified pea protein is fully dissolved;

[0049] Step 3-2: Accurately weigh 4.9-5.1 g of the modified pea protein solution and place it in a 10 mL glass container with a stopper, and remove the bubbles on the surface;

[0050] Step 3-3: Place the modified pea protein solution in a constant temperature water bath and heat it for 15-20 minutes at a temperature of 80-95°C. After heating, quickly cool it in an ice bath for 20-40 minutes, and then place it in a refrigerator at 4°C for 12-24 hours.

[0051] In addition to the above steps, the specific implementation also includes step 4: analyzing the characteristics of the prepared heat-induced pea protein isolate gel, including gel strength, gel water retention and morphology observation.

[0052] Comparative Example 1

[0053] Comparative Example 1 provides a method for regulating the strength and water holding capacity of pea protein isolate gel based on acoustic resonance technology, comprising the following steps:

[0054] Step 1: Weigh and package the powdered pea protein isolate according to a certain mass at 25°C, and store it in a dry environment until processing.

[0055] Step 2: subjecting the packaged pea protein isolate to an acoustic resonance treatment, specifically comprising the following steps:

[0056] Step 2-1: Add the packaged pea protein isolate powder into stainless steel sample tanks respectively; wherein the mass of the protein sample added is 50 g, and the capacity of the sample tank is 500 mL.

[0057] Step 2-2: Add white beads of appropriate mass into the sample jar as a medium to assist in protein fragmentation; wherein the diameter of the beads is 2 mm.

[0058] Step 2-3: Start processing the sample in a 20°C environment, set and adjust the operating parameters of the acoustic resonance instrument; among which, the acoustic resonance processing frequency is set to 61.2 Hz, the processing amplitude is 35%, the processing acceleration is 70.000 g, and the processing time is 0 min, which serves as a control group.

[0059] Step 2-4: After the acoustic resonance treatment is completed, the modified protein sample is quickly collected and sealed in a desiccator for storage.

[0060] Step 3: The pea protein obtained in step 2 is prepared into a heat-induced gel, and the specific process includes the following steps:

[0061] Step 3-1: Prepare a pea protein solution with a concentration of 17 mg / mL and an ionic strength of 0.2 mol / L (NaCl), and stir magnetically for 30 minutes to ensure that the pea protein is fully dissolved;

[0062] Step 3-2: Accurately weigh 5.0 g of the above pea protein solution and place it in a 10 mL glass container with a stopper, and remove the bubbles on the surface;

[0063] Step 3-3: The pea protein solution was placed in a constant temperature water bath and heated at 95°C for 15 minutes. After heating, the solution was rapidly cooled in an ice bath for 30 minutes and then placed in a refrigerator at 4°C for 20 hours.

[0064] Step 4: Analyze the properties of the prepared heat-induced pea protein isolate gel, including gel strength, gel water retention and morphology observation.

[0065] Example 1

[0066] This embodiment 1 provides a method for regulating the strength and water holding capacity of pea protein isolate gel based on acoustic resonance technology, comprising the following steps:

[0067] Step 1: Weigh and package the powdered pea protein isolate according to a certain mass at 25°C, and store it in a dry environment until processing.

[0068] Step 2: subjecting the packaged pea protein isolate to an acoustic resonance treatment, specifically comprising the following steps:

[0069] Step 2-1: Add the packaged pea protein isolate powder into stainless steel sample tanks respectively; wherein the mass of the protein sample added is 50 g, and the capacity of the sample tank is 500 mL.

[0070] Step 2-2: Add white beads of appropriate mass into the sample jar as a medium to assist in protein fragmentation; wherein the diameter of the beads is 2 mm.

[0071] Step 2-3: Start processing the sample in an environment of 20°C, set and adjust the operating parameters of the acoustic resonance instrument; wherein, the acoustic resonance processing frequency is set to 61.2 Hz, the processing amplitude is 35%, the processing acceleration is 70.000 g, and the processing time is 5 min.

[0072] Step 2-4: After the acoustic resonance treatment is completed, the modified protein sample is quickly collected and sealed in a desiccator for storage.

[0073] Step 3: The modified pea protein obtained in step 2 is prepared into a heat-induced gel, and the specific process includes the following steps:

[0074] Step 3-1: prepare a modified pea protein solution with a concentration of 17 mg / mL and an ionic strength of 0.2 mol / L (NaCl), and stir magnetically for 30 minutes to ensure that the modified pea protein is fully dissolved;

[0075] Step 3-2: Accurately weigh 5.0 g of the modified pea protein solution and place it in a 10 mL glass container with a stopper, and remove the bubbles on the surface;

[0076] Step 3-3: The modified pea protein solution was placed in a constant temperature water bath and heated for 15 minutes at 95°C. After heating, the solution was rapidly cooled in an ice bath for 30 minutes and then placed in a refrigerator at 4°C for 20 hours.

[0077] Step 4: Analyze the properties of the prepared heat-induced pea protein isolate gel, including gel strength, gel water retention and morphology observation.

[0078] Example 2

[0079] This embodiment 2 provides a method for regulating the strength and water holding capacity of pea protein isolate gel based on acoustic resonance technology, comprising the following steps:

[0080] Step 1: Weigh and package the powdered pea protein isolate according to a certain mass at 25°C, and store it in a dry environment until processing.

[0081] Step 2: subjecting the packaged pea protein isolate to an acoustic resonance treatment, specifically comprising the following steps:

[0082] Step 2-1: Add the packaged pea protein isolate powder into stainless steel sample tanks respectively; wherein the mass of the protein sample added is 50 g, and the capacity of the sample tank is 500 mL.

[0083] Step 2-2: Add white beads of appropriate mass into the sample jar as a medium to assist in protein fragmentation; wherein the diameter of the beads is 2 mm.

[0084] Step 2-3: Start processing the sample in a 20°C environment, set and adjust the operating parameters of the acoustic resonance instrument; wherein the acoustic resonance processing frequency is set to 61.2 Hz, the processing amplitude is 35%, the processing acceleration is 70.000 g, and the processing time is 10 min.

[0085] Step 2-4: After the acoustic resonance treatment is completed, the modified protein sample is quickly collected and sealed in a desiccator for storage.

[0086] Step 3: The modified pea protein obtained in step 2 is prepared into a heat-induced gel, and the specific process includes the following steps:

[0087] Step 3-1: prepare a modified pea protein solution with a concentration of 17 mg / mL and an ionic strength of 0.2 mol / L (NaCl), and stir magnetically for 30 minutes to ensure that the modified pea protein is fully dissolved;

[0088] Step 3-2: Accurately weigh 5.0 g of the modified pea protein solution and place it in a 10 mL glass container with a stopper, and remove the bubbles on the surface;

[0089] Step 3-3: The modified pea protein solution was placed in a constant temperature water bath and heated at 95°C for 15 minutes. After heating, the solution was rapidly cooled in an ice bath for 30 minutes and then placed in a refrigerator at 4°C for 20 hours.

[0090] Step 4: Analyze the properties of the prepared heat-induced pea protein isolate gel, including gel strength, gel water retention and morphology observation.

[0091] Example 3

[0092] This embodiment 3 provides a method for regulating the strength and water holding capacity of pea protein isolate gel based on acoustic resonance technology, comprising the following steps:

[0093] Step 1: Weigh and package the powdered pea protein isolate according to a certain mass at 25°C, and store it in a dry environment until processing.

[0094] Step 2: subjecting the packaged pea protein isolate to an acoustic resonance treatment, specifically comprising the following steps:

[0095] Step 2-1: Add the packaged pea protein isolate powder into stainless steel sample tanks respectively; wherein the mass of the protein sample added is 50 g, and the capacity of the sample tank is 500 mL.

[0096] Step 2-2: Add white beads of appropriate mass into the sample jar as a medium to assist in protein fragmentation; wherein the diameter of the beads is 2 mm.

[0097] Step 2-3: Start processing the sample in an environment of 20°C, set and adjust the operating parameters of the acoustic resonance instrument; wherein, the acoustic resonance processing frequency is set to 61.2 Hz, the processing amplitude is 35%, the processing acceleration is 70.000 g, and the processing time is 15 min.

[0098] Step 2-4: After the acoustic resonance treatment is completed, the modified protein sample is quickly collected and sealed in a desiccator for storage.

[0099] Step 3: The modified pea protein obtained in step 2 is prepared into a heat-induced gel, and the specific process includes the following steps:

[0100] Step 3-1: prepare a modified pea protein solution with a concentration of 17 mg / mL and an ionic strength of 0.2 mol / L (NaCl), and stir magnetically for 30 minutes to ensure that the modified pea protein is fully dissolved;

[0101] Step 3-2: Accurately weigh 5.0 g of the modified pea protein solution and place it in a 10 mL glass container with a stopper, and remove the bubbles on the surface;

[0102] Step 3-3: The modified pea protein solution was placed in a constant temperature water bath and heated at 95°C for 15 minutes. After heating, the solution was rapidly cooled in an ice bath for 30 minutes and then placed in a refrigerator at 4°C for 20 hours.

[0103] Step 4: Analyze the properties of the prepared heat-induced pea protein isolate gel, including gel strength, gel water retention and morphology observation.

[0104] Example 4

[0105] This embodiment 4 provides a method for regulating the strength and water holding capacity of pea protein isolate gel based on acoustic resonance technology, comprising the following steps:

[0106] Step 1: Weigh and package the powdered pea protein isolate according to a certain mass at 25°C, and store it in a dry environment until processing.

[0107] Step 2: subjecting the packaged pea protein isolate to an acoustic resonance treatment, specifically comprising the following steps:

[0108] Step 2-1: Add the packaged pea protein isolate powder into stainless steel sample tanks respectively; wherein the mass of the protein sample added is 50 g, and the capacity of the sample tank is 500 mL.

[0109] Step 2-2: Add white beads of appropriate mass into the sample jar as a medium to assist in protein fragmentation; wherein the diameter of the beads is 2 mm.

[0110] Step 2-3: Start processing the sample in a 20°C environment, set and adjust the operating parameters of the acoustic resonance instrument; wherein the acoustic resonance processing frequency is set to 61.2 Hz, the processing amplitude is 35%, the processing acceleration is 70.000 g, and the processing time is 20 min.

[0111] Step 2-4: After the acoustic resonance treatment is completed, the modified protein sample is quickly collected and sealed in a desiccator for storage.

[0112] Step 3: The modified pea protein obtained in step 2 is prepared into a heat-induced gel, and the specific process includes the following steps:

[0113] Step 3-1: prepare a modified pea protein solution with a concentration of 17 mg / mL and an ionic strength of 0.2 mol / L (NaCl), and stir magnetically for 30 minutes to ensure that the modified pea protein is fully dissolved;

[0114] Step 3-2: Accurately weigh 5.0 g of the modified pea protein solution and place it in a 10 mL glass container with a stopper, and remove the bubbles on the surface;

[0115] Step 3-3: The modified pea protein solution was placed in a constant temperature water bath and heated at 95°C for 15 minutes. After heating, the solution was rapidly cooled in an ice bath for 30 minutes and then placed in a refrigerator at 4°C for 20 hours.

[0116] Step 4: Analyze the properties of the prepared heat-induced pea protein isolate gel, including gel strength, gel water retention and morphology observation.

[0117] Example 5

[0118] This embodiment 5 provides a method for regulating the strength and water holding capacity of pea protein isolate gel based on acoustic resonance technology, comprising the following steps:

[0119] Step 1: Weigh and package the powdered pea protein isolate according to a certain mass at 25°C, and store it in a dry environment until processing.

[0120] Step 2: subjecting the packaged pea protein isolate to an acoustic resonance treatment, specifically comprising the following steps:

[0121] Step 2-1: Add the packaged pea protein isolate powder into stainless steel sample tanks respectively; wherein the mass of the protein sample added is 50 g, and the capacity of the sample tank is 500 mL.

[0122] Step 2-2: Add white beads of appropriate mass into the sample jar as a medium to assist in protein fragmentation; wherein the diameter of the beads is 2 mm.

[0123] Step 2-3: Start processing the sample in a 20°C environment, set and adjust the operating parameters of the acoustic resonance instrument; wherein the acoustic resonance processing frequency is set to 61.2 Hz, the processing amplitude is 35%, the processing acceleration is 70.000 g, and the processing time is 30 min.

[0124] Step 2-4: After the acoustic resonance treatment is completed, the modified protein sample is quickly collected and sealed in a desiccator for storage.

[0125] Step 3: The modified pea protein obtained in step 2 is prepared into a heat-induced gel, and the specific process includes the following steps:

[0126] Step 3-1: prepare a modified pea protein solution with a concentration of 17 mg / mL and an ionic strength of 0.2 mol / L (NaCl), and stir magnetically for 30 minutes to ensure that the modified pea protein is fully dissolved;

[0127] Step 3-2: Accurately weigh 5.0 g of the modified pea protein solution and place it in a 10 mL glass container with a stopper, and remove the bubbles on the surface;

[0128] Step 3-3: The modified pea protein solution was placed in a constant temperature water bath and heated at 95°C for 15 minutes. After heating, the solution was rapidly cooled in an ice bath for 30 minutes and then placed in a refrigerator at 4°C for 20 hours.

[0129] Step 4: Analyze the properties of the prepared heat-induced pea protein isolate gel, including gel strength, gel water retention and morphology observation.

[0130] Experimental methods

[0131] Determination of gel strength of heat-induced pea protein isolate

[0132] The sample gel strength was measured using a TA-XT Plus physical property analyzer. The gel sample needs to be balanced at room temperature for 30 minutes before measurement. Measurement mode: pre-measurement rate is 1mm / s; measurement rate is 1mm / s; post-measurement rate is 10mm / s; the downward pressure distance is 6mm, and the probe model is P / 0.5. The gel strength is calculated using the following formula:

[0133] Gel strength (g cm) = gel rupture strength (g) × deformation distance (cm)

[0134] Determination of water holding capacity of heat-induced pea protein isolate gel

[0135] Weigh about 5g of heat-induced pea protein isolate into a centrifuge tube, centrifuge at 10,000×g for 15 minutes at 4°C, invert the tube to remove the supernatant, and use filter paper to absorb excess water, weigh, and record the weight of the sample and the bottle before and after centrifugation. Use the following formula to calculate the water holding rate of the gel:

[0136]

[0137] In the formula,

[0138] W 1 ——Mass of centrifuge tube, g;

[0139] W 2 ——Mass of centrifuge tube and gel, g;

[0140] W 3 ——Mass of centrifuge tube and gel after centrifugation, g.

[0141] Observation on the morphology of heat-induced pea protein isolate

[0142] General morphology observation

[0143] The heat-induced pea protein isolate samples were equilibrated at room temperature for 30 minutes and quickly photographed and recorded in a studio.

[0144] Microstructure observation

[0145] The prepared heat-induced pea protein isolate was cut into pieces, fixed with 2.5% glutaraldehyde for 4 h, washed once with distilled water, dehydrated with ethanol at a gradient of 50%, 70%, 90%, 95% and 100%, with the dehydration time being 30 min each time, and then freeze-dried at -80°C. Part of the sample was taken, and the protein gel microstructure was observed using a scanning electron microscope after gold spraying, with a magnification of 6500 times and an accelerating voltage of 2 kV.

[0146] Experimental Results

[0147] Gelation is one of the most important properties of food protein. Gelation is mainly a property of protein forming an alternating three-dimensional network structure, and the formed gel is a dispersed system in which water is dispersed in protein, with a certain viscosity and elasticity, and has the properties of a solid. Figure 2As shown in the figure, compared with the heat-induced pea protein isolate gel without acoustic resonance treatment, the gel strength of the heat-induced pea protein isolate gel after acoustic resonance treatment was significantly reduced by more than 6.66%; among them, the strength of the heat-induced pea protein isolate gel treated with acoustic resonance for 20 minutes was the lowest, which was 57.91g cm, which was 35.94% lower than the untreated protein gel strength. The uniform shear force field generated during the acoustic resonance treatment acted on the inside of the pea protein (globulin), and the spatial conformation changed, the active groups were further exposed, and the size of the protein aggregates decreased. In the process of forming the heat-induced gel, the interaction between proteins was relatively reduced, and the gel texture became softer; at the same time, within a certain time range, the acoustic resonance treatment time was negatively correlated with the strength of the pea protein isolate gel. Such changes are consistent with the principle of solving the swallowing problem and the selection of consumer food characteristics. On the contrary, the strength of the protein gel treated with acoustic resonance for 30 minutes was slightly improved, because the longer acoustic resonance effect would generate a lot of heat, which would cause the protein to oxidize and further aggregate the structure.

[0148] Water holding capacity is one of the important functional properties of gel food, which describes the water entrapment in the gel network structure and is closely related to the texture (hardness, elasticity, viscosity and tenderness) of the gel product. Figure 3 As shown in the figure, the water holding capacity of pea protein isolate gel can be effectively improved by acoustic resonance treatment. Compared with the heat-induced pea protein isolate gel without acoustic resonance treatment, the water holding capacity of heat-induced pea protein isolate gel in the acoustic resonance treatment group increased by more than 7.83%; at the same time, the water holding capacity of protein gel first increased and then decreased with the extension of acoustic resonance treatment time; among them, the best effect of 20min acoustic resonance treatment was 84.01%. This shows that the acoustic resonance effect of appropriate time helps to strengthen the interaction between protein and water molecules; on the contrary, the water holding capacity of protein gel treated with 30min acoustic resonance treatment decreased slightly, which is similar to the result of 15min acoustic resonance treatment, indicating that too long treatment is not conducive to the interaction between protein and water.

[0149] like Figure 4 , Figure 5As shown in the figure, the surface structure characteristic diagram and microstructure diagram of the gel prepared by the heat-induced pea protein isolate treated with acoustic resonance. The surface and internal structure of the heat-induced pea protein isolate gel without acoustic resonance treatment are very rough, with large holes; after 5-20 minutes of acoustic resonance treatment, the surface structure of the heat-induced pea protein isolate gel gradually becomes flat and smooth, especially under 20 minutes of treatment, the heat-induced pea protein isolate gel structure is delicate and smooth, and the most uniform and delicate gel three-dimensional network structure is formed inside; on the contrary, the heat-induced pea protein isolate gel structure treated with 30 minutes of acoustic resonance is rougher than that treated with 20 minutes. Therefore, choosing an appropriate acoustic resonance treatment time is helpful to improve the gel properties of pea protein isolate.

[0150] The above experiments prove that the present invention effectively regulates the gel strength of pea protein isolate by using the acoustic resonance technology to develop more high-quality, easy-to-intake and easy-to-absorb green plant protein foods suitable for special groups of people; at the same time, the acoustic resonance treatment also significantly enhances the water-holding capacity of the pea protein isolate gel, the gel surface is smoother, and the three-dimensional network structure is more uniform, which helps to provide a soft and stable texture; therefore, in the development of functional foods, the application of acoustic resonance technology is expected to improve the gel properties and processing properties of natural pea protein, develop pea protein products with various sizes, shapes and textures, and improve the quality of pea protein and the economic benefits of the enterprise.

[0151] Although the present invention has been described in detail in the embodiments through general explanations, specific implementation methods and experiments, modifications or improvements can still be made without departing from the core of the present invention, and all belong to the scope of protection required by the present invention.

Claims

1. A method for regulating the strength and water holding capacity of pea protein isolate gel based on acoustic resonance technology, characterized in that: It consists of the following steps: Step 1: Weigh a certain amount of powdered pea protein isolate for packaging; Step 2: putting the packaged pea protein isolates into acoustic resonance mixing containers respectively, and subjecting them to acoustic resonance treatment to obtain modified pea protein; Step 3: preparing the modified pea protein obtained by the treatment in step 2 into a heat-induced gel; The acoustic resonance treatment process of pea protein isolate in step 2 is specifically as follows: Step 2-1: Place the packaged pea protein isolate into acoustic resonance mixing containers respectively; Step 2-2: Add an appropriate amount of white pickaxe beads to the mixing container as a medium to assist in protein fragmentation; Step 2-3: Set and adjust the operating parameters of the acoustic resonance instrument to process the sample. The operating parameters of the acoustic resonance instrument are as follows: the processing frequency is 55-65 Hz, the processing amplitude is 30-40%, the processing acceleration is 65.000-75.000 g, and the processing time is within 30 min; Step 2-4: After the acoustic resonance treatment, the modified protein sample is quickly collected and sealed in a desiccator for storage; The process of preparing the modified pea protein into a heat-induced gel in step 3 is specifically as follows: Step 3-1: preparing a modified pea protein solution of a certain concentration and ionic strength, and magnetically stirring to ensure that the modified pea protein is fully dissolved; Step 3-2: Weigh a certain amount of the modified pea protein solution and place it in a glass container with a stopper, and remove the bubbles on the surface; Step 3-3: Place the modified pea protein solution in a constant temperature water bath and heat it for a certain period of time. After heating, quickly cool it in an ice bath and then place it in a 4°C refrigerator. The water bath heating time is 15-20 min, the heating temperature is 80-95°C, and the rapid cooling time is 20-40 min.

2. The method for regulating the gel strength and water holding capacity of pea protein isolate based on acoustic resonance technology according to claim 1, characterized in that: The diameter of the white pickaxe bead in step 2-2 is 2 mm.

3. The method for regulating the gel strength and water holding capacity of pea protein isolate based on acoustic resonance technology according to claim 1, characterized in that: The concentration of the modified pea protein solution in step 3-1 is 16-20 mg / mL, and the ionic strength is 0-0.4 mol / L (NaCl).

4. The method for regulating the gel strength and water holding capacity of pea protein isolate based on acoustic resonance technology according to claim 1, characterized in that: The magnetic stirring time of the modified pea protein solution in step 3-1 is 30-60 min.

5. The method for regulating the gel strength and water holding capacity of pea protein isolate based on acoustic resonance technology according to claim 1, characterized in that: The modified pea protein solution after heating and cooling in step 3-3 is placed in a 4° C. refrigerator for 12-24 h.

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