Pea protein high-valued preparation method and system based on molecular level structure regulation and enzymolysis targeting synergy

Abstract

The invention provides a pea protein high-valued preparation method and system based on molecular level structure regulation and enzymolysis targeting synergy, and belongs to the field of vegetable protein functional processing. Pure natural pea meal is taken as a raw material, a porous structure is directionally generated through a superheated steam instantaneous phase change blasting mechanism, and phytic acid inactivation and endogenous enzyme retention are synchronously realized; by combining alpha-amylase to precut starch, alpha-galactosidase to degrade oligosaccharide in a targeted manner and a double-enzyme gradient time sequence activation mechanism, the enzymolysis competitive inhibition problem is solved; and finally, the protein dissolution index and digestibility are improved through microporous nanofiber compounding and a multi-scale structure interaction mechanism, and a steam-enzymolysis collaborative module is integrated in the system, so that an innovative solution is provided for natural plant protein processing. The obtained thin bean flour has breakthrough integration of nutritional advantages of pea protein and natural viscoelasticity regulation and control characteristics, has cold and hot double-soluble quick-acting property, low sensitization and long-term preservation property, and can be expanded to the field of precise nutritional food development.

Description

Technical Field

[0001] This invention relates to the field of plant protein processing technology, and in particular to a method and system for high-value preparation of pea protein based on molecular-level structure regulation and targeted enzymatic hydrolysis, which is applicable to the development of natural health foods. Background Technology

[0002] Xidoufen, a representative traditional snack of Yunnan, is made from high-quality peas through a series of traditional handcrafted processes including soaking, grinding, filtering, and cooking. The finished product is pale yellow in color and has a delicate, smooth texture. It can be eaten with various seasonings or combined with rice noodles and fried dough sticks for a unique flavor. Because peas are rich in plant protein and dietary fiber, they have nutritional benefits such as regulating qi, relieving dampness, and detoxifying. However, traditional xidoufen processing relies heavily on manual labor, resulting in a short shelf life (no more than 3 days at room temperature) and the need for immediate consumption, making it difficult to adapt to the demands of modern fast-paced life and industrialized production. While existing technologies have attempted to develop instant xidoufen products using pea flour as a base to meet the market's urgent need for convenient ready-to-eat foods, they suffer from several significant drawbacks. For example, traditional processing methods often result in insufficient starch gelatinization and coarse particles, leading to clumping during preparation, long dissolving times, a rough texture, and a noticeable beany taste. Furthermore, the inability to effectively inhibit starch retrogradation and lipid oxidation typically results in a shelf life of less than 6 months. Furthermore, the protein content of single pea raw materials is relatively low. Some existing improvement technologies improve solubility by adding emulsifiers or maltodextrin, but this destroys the natural flavor of the product and reduces its nutritional value. Conventional processing equipment has low temperature control precision and high energy consumption, and cannot accurately control the segmented gelatinization and puffing process, resulting in poor product uniformity.

[0003] With consumers' rapidly increasing demands for food convenience (instant dissolution in cold / hot water), nutritional diversity (high protein, low starch), and sensory quality (smooth texture, natural color), existing technologies struggle to balance efficient processing with quality improvement. For example, the existing patent for sprouted brown rice (CN104187434A) suffers from insufficient retention of active nutritional components, low raw material pretreatment efficiency, limited optimization of taste and texture, and insufficient synergistic effects in formulations. Traditional extrusion puffing processes, due to their limited temperature control, result in high starch degradation rates and a lack of functional adjuvants, failing to optimize product structure and solubility through synergistic effects between components. Therefore, there is an urgent need to develop a systematic solution that integrates processing technology upgrades with intelligent equipment, overcoming technical bottlenecks in solubility, shelf life, and nutritional function while preserving traditional flavors, thus paving a new industrialization path for plant-based convenience foods. Summary of the Invention

[0004] This invention addresses the technical problems of traditional pea flour, such as poor solubility, easy clumping, rough texture, and short shelf life, by proposing a method and system for high-value preparation of pea protein based on molecular-level structure regulation and targeted enzymatic hydrolysis.

[0005] The technical solution of the present invention:

[0006] A method for high-value preparation of pea protein based on the synergistic effect of molecular-level structure regulation and enzymatic hydrolysis targeting, characterized in that: the raw material is 100% pea flour, and the method includes the following steps:

[0007] (1) Superheated steam instantaneous phase change explosion treatment: Pea flour is placed in a superheated steam environment, and micron-level shear force is generated by the instantaneous vaporization of liquid water to construct a porous framework network in a directional manner, so as to simultaneously achieve phytic acid degradation and retention of endogenous enzyme activity.

[0008] (2) Two-enzyme gradient sequential digestion: The product of step (1) is sequentially digested as follows:

[0009] a) High-temperature enzymatic hydrolysis: Hydrolyzing amylose using α-amylase;

[0010] b) Low-temperature enzymatic hydrolysis: α-galactosidase is used to target and cleave α-1,6-galactosidic bonds.

[0011] (3) Multiscale structural composite: The product of step (2) is subjected to extrusion and shearing treatment to induce the generation of nanofibers that penetrate the microporous skeleton, forming a microporous-nanofiber interpenetrating network structure.

[0012] (4) Spray drying: The product from step (3) is spray dried to obtain pea protein powder.

[0013] Further, in step (1), the superheated steam environment conditions are: pressure 0.8-1.2 MPa, temperature 160-180℃, superheated steam penetration depth 1.2-1.5 times (preferably 1.3-1.5 times) the diameter of pea flour particles, and superheated steam instantaneous phase change explosion treatment time 15-25 s (preferably 18-25 s); the shear rate of micron-level shear force ≥10 4 s -1 (Preferred: 1.2-1.5×10) 4 s -1 The porous framework network has a porosity of 66-70%; phytic acid degradation rate ≥90%; and endogenous enzyme activity retention ≥85%.

[0014] Further, in step (2), the high-temperature enzymatic hydrolysis temperature is 55-65℃ (preferably 55-60℃), the time is 25-35min, and the pH is 6.5-7.0 (preferably 6.5-6.8); the degree of hydrolysis is controlled to be ≥40%, and the system viscosity is reduced to <50mPa·s; the low-temperature enzymatic hydrolysis temperature is 45-55℃ (preferably 45-50℃), the time is 55-75min, and the pH is 4.5-5.5 (preferably 4.5-5); the mass ratio of α-amylase to pea flour is 1:100-1:80, and the mass ratio of α-galactosidase to pea flour is 1:200-1:125; the switching rate of the two enzymatic hydrolysis temperatures is 5-8℃ / min.

[0015] Further, in step (3), the screw speed of the extrusion shearing treatment is 300-400 rpm (preferably 300-350 rpm), the shear stress is 1.5-2.0 MPa (preferably 1.5-1.8 MPa), and the treatment time is 10-15 min; the diameter of the micropores in the nanofiber-permeable microporous skeleton is 50-100 nm (preferably 75-82 nm), and the water holding capacity of the microporous-nanofiber interpenetrating network structure is ≥8 g / g.

[0016] Furthermore, in step (4), the inlet air temperature for drying is 180-200℃ (preferably 180-190℃) and the outlet air temperature is 80-90℃ (preferably 80-85℃).

[0017] Furthermore, the interfacial bonding energy between the nanofibers and the microporous framework in the prepared pea protein powder is 25-35 mJ / m. 2 (Preferred 27-35mJ / m 2 The pea protein powder has a water contact angle of 15-40° (preferably 30-38°), an oxidation induction time of 30-50 min (preferably 38-46 min) for its lipid components, a solubility index (SI) ≥ 85%, and a digestibility ≥ 90%. The allergenic protein epitope masking rate is ≥ 80%, the IgE binding activity is < 0.15 IU / g, and the resulting pea protein powder has a storage modulus G' = 350 ± 50 Pa (preferably 330-375 Pa) and a loss tangent tanδ = 0.12-0.18 (preferably 0.13-0.16).

[0018] A system for the high-value preparation of pea protein based on the synergistic effect of molecular-level structure regulation and enzymatic hydrolysis targeting, the system comprising a steam phase change regulation module, an enzymatic hydrolysis timing control module, a co-rotating twin-screw extruder, and a spray drying device.

[0019] Furthermore, the steam phase change control module is used to realize the directional construction of the porous structure, integrating a feed inlet (101), a condensate outlet (102), a secondary steam outlet (103), an evaporation chamber (104), a heating steam inlet (105), a heating chamber (106), and a discharge outlet (107); the feed inlet (101) is located at the lower part of the evaporation chamber (104) for quantitatively introducing pea flour material; the secondary steam outlet (103) is located at the top of the evaporation chamber (104) for discharging the secondary steam generated by evaporation; the heating chamber (106) is located below the evaporation chamber (104), and the two are connected, the heating chamber (106) is used to contain superheated steam and provide phase change heat transfer heat; heating A steam inlet (105) is located at the top of the heating chamber (106) and connected to the heating steam of the external steam pipeline network; a condensate outlet (102) and a discharge port (107) are located at the bottom of the heating chamber (106) and are used to discharge condensate and the material after evaporation, concentration and porous structure regulation, respectively; the discharge port (107) is connected to the inlet of the enzymatic hydrolysis timing control module; the material to be processed enters the evaporation chamber (104) from the feed inlet (101), and the external heating steam enters the heating chamber (106) through the heating steam inlet (105), drives evaporation through heat exchange, and the generated secondary steam is discharged through the secondary steam outlet (103), and the final product is discharged from the evaporation chamber (104) through the discharge port (107).

[0020] The enzymatic hydrolysis timing control module adopts a concentric cylindrical dual-temperature zone reaction tower to overcome competitive inhibition: the central high-temperature zone (202) has a built-in high-temperature filling layer (203), and the outer low-temperature zone (206) wraps around the central high-temperature zone (202) and has a built-in low-temperature filling layer (205). The two zones are physically isolated by a thermal barrier partition (204). The feed inlet is located at the top of the high-temperature zone (202) and is connected to the material outlet of the steam phase change control module. After the reaction in the central high-temperature zone (202), the material enters the low-temperature filling layer (205) through the central channel of the thermal barrier partition (204) and is finally discharged to the co-rotating twin-screw extruder from the bottom outlet of the low-temperature zone (206).

[0021] The co-rotating twin-screw extruder is used to construct a microporous-nanofiber interpenetrating network structure. It includes a co-rotating twin-screw body (301), a drive device (302), a co-rotating twin-screw extruder inlet (303), and a co-rotating twin-screw extruder outlet (304). The co-rotating twin-screw extruder inlet (303) and the co-rotating twin-screw extruder outlet (304) are respectively located at both ends of the co-rotating twin-screw extruder. The co-rotating twin-screw extruder outlet (304) is connected to a spray drying device. The co-rotating twin screws are arranged horizontally side by side in the central axial direction of the co-rotating twin-screw extruder. The co-rotating twin screws are driven to rotate by the drive device (302) and break down protein aggregates by mechanical shear force.

[0022] Furthermore, in the early stage of using the steam phase change control module, before the pea flour material is introduced, the condensate generated due to the ambient temperature difference after the heating steam inlet (105) enters the heating chamber (106) and evaporation chamber (104) is discharged through the condensate outlet (102). After the temperature of the heating chamber (106) and evaporation chamber (104) rises to the steam temperature, no condensate is generated, and then the pea flour material is introduced from the feed inlet (101). In the enzymatic hydrolysis timing control module, the temperature sensor (201) and enzyme activity probe are respectively connected to the high-temperature filling layer (203) and the low-temperature filling layer (205) for real-time monitoring of temperature parameters, α-amylase and α-galactosidase activities; the pH adaptive adjustment unit injects buffer solution (response ≤ 5 seconds) into the high-temperature filling layer (203) and the low-temperature filling layer (205) through a ring pipe. The control panel (207) works with the sensor (201), enzyme activity probe and pH adaptive adjustment unit to achieve precise control of dual temperature zones. The heat barrier partition (204) is a vacuum insulation layer, double-sided covered with a high-temperature resistant ceramic coating; ensuring a temperature difference ≥10℃. The high-temperature filling layer (203) is made of 316L stainless steel with a pore size of 0.5-1mm, and the low-temperature filling layer (205) is made of PTFE with a pore size of 0.2-0.5mm. The co-rotating twin-screw body (301) in the co-rotating twin-screw extruder has a length-to-diameter ratio of 40:1 and is suitable for diameters of 70-80mm.

[0023] The pea protein powder prepared by the above method can be used in the preparation of infant complementary food, elderly nutritional products or functional foods: the pea protein powder can be rehydrated to form a stable colloid with a solid content of 15-25% and a shelf life of more than 18 months.

[0024] The beneficial effects of this invention are:

[0025] (1) Raw material innovation

[0026] Using 100% pea flour as a base, a breakthrough in in-situ synergistic conversion of pea protein, starch, and fiber is achieved through a single raw material full-component utilization strategy, avoiding the nutrient dilution effect of compound raw materials while retaining the natural flavor substances of peas.

[0027] (2) Core technology innovation

[0028] Steam phase change explosion - dual-enzyme sequential cleavage - multi-scale structural composite three-stage synergistic process:

[0029] (A) Pretreatment for instantaneous phase change explosion of superheated steam

[0030] A superheated steam generator is used to instantaneously process pea flour, generating micron-level shear force through liquid water vaporization to directionally construct a porous framework network with a porosity of 60-70%; simultaneously achieving targeted pyrolysis of phytic acid and protection of endogenous enzyme activity.

[0031] (B) Two-enzyme gradient sequential digestion

[0032] The high-temperature range (55-65℃) preferentially activates α-amylase: hydrolyzes amylose (degree of hydrolysis ≥40%), breaks down the starch-protein interaction network, reduces the viscosity of the system, and is much lower than that of traditional diluted soybean flour;

[0033] Low temperature range (45-55℃) targets and activates α-galactosidase: specifically cleaves α-1,6-galactosidic bonds, degrades oligosaccharides such as raffinose and stachyose (residual amount ≤0.5%), and eliminates bloating factors;

[0034] Enzyme activation is achieved through a dual-temperature zone reaction tower (temperature switching rate 5-8℃ / min), overcoming competitive inhibition.

[0035] (C) Construction of microporous nanofiber composite structure

[0036] A co-rotating twin-screw extruder was used, with the screw speed set at 300-400 rpm and the shear stress at 1.5-2.0 MPa, to induce pea protein to self-assemble into nanofibers with a diameter of 50-100 nm.

[0037] (3) Equipment Innovation

[0038] (A) Steam Phase Change Control Module

[0039] The innovative design employs a dual-chamber structure for evaporation and heating, with a bottom heating chamber providing a stable phase change heat source to enable directional steam permeation from bottom to top within the pea flour particles, effectively guiding the vertical construction of the porous structure.

[0040] The system integrates a secondary steam discharge and condensate separation system, optimizes the evaporation path and heat recovery efficiency, and ensures the stability and continuity of the temperature and humidity environment during the formation of the pore structure.

[0041] (B) Enzymatic hydrolysis timing control module

[0042] The dual-temperature zone reaction tower is equipped with a thermal barrier baffle, and the temperature zone switching response time is ≤30s;

[0043] The built-in online enzyme activity monitoring probe (detection limit 0.01 U / mL) and pH adaptive adjustment unit (adjustment accuracy ±0.1) ensure the stability of enzymatic hydrolysis efficiency.

[0044] (C) Structural composite module

[0045] A co-rotating twin-screw extruder induces the self-assembly of pea protein to generate nanofibers.

[0046] (4) Product characteristics

[0047] The resulting instant soybean powder is light yellow in color, with a whiteness L* value ≥92, a delicate texture, and a combination of soybean aroma and glutinous texture. It has a shelf life of ≥18 months and can be extended to the fields of infant complementary food, elderly nutritional products and functional foods.

[0048] (5) Effect characteristics

[0049] (A) Improved process efficiency: The steam phase change explosion treatment time is reduced to 1 / 5 of the traditional heat treatment, and the enzymatic hydrolysis efficiency is increased by 2.3 times;

[0050] (B) Product added value doubles: Protein utilization rate increases from 65% in traditional processes to 92%, and can directly replace commercially available whey protein;

[0051] (C) Industrial adaptability: The modular system is compatible with existing food production lines, reducing unit energy consumption by 35%;

[0052] (D) Application scalability: It can be rehydrated to form a stable colloid with a solid content of 15-25%, and can withstand 121℃ moist heat sterilization, making it suitable for aseptic filling needs of infant complementary food, elderly nutritional products, etc.

[0053] This invention breaks through the technical bottleneck of traditional soybean powder through a systematic approach involving raw material compounding, process innovation, and equipment upgrading, providing an innovative solution for the field of high-nutrition instant food. Attached Figure Description

[0054] Figure 1 : Instant instant soybean powder preparation diagram, (a) traditional soybean powder; (b) instant instant soybean powder.

[0055] Figure 2 Flowchart for the preparation of instant and convenient soybean powder.

[0056] Figure 3 Schematic diagram of the steam phase change control module.

[0057] Figure 4 Dual-temperature zone enzymatic hydrolysis intelligent reaction system.

[0058] Figure 5 Nanofiber electric field orientation extruder.

[0059] Figure 6 A high-value preparation system for pea protein through synergistic molecular structure regulation and enzymatic hydrolysis targeting. Detailed Implementation

[0060] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0061] It should be noted that the sequence number mentioned in this application does not necessarily mean that the execution must be strictly in the correct order in the actual implementation process. The sequence number is used to distinguish each step, facilitate explanation, and prevent confusion.

[0062] Currently, existing technologies for producing pea flour involve cumbersome processes, excessively long cooking times, low efficiency, and low standardization, making it difficult to meet consumer demands. This invention provides a method and system for high-value preparation of pea protein based on molecular-level structure regulation and targeted enzymatic hydrolysis.

[0063] Example 1:

[0064] (1) Superheated steam instantaneous phase change explosion treatment: 10 kg of 100 mesh pea flour is placed in a superheated steam environment. Micron-level shear force is generated by the instantaneous vaporization of liquid water to construct a porous framework network in a directional manner, so as to simultaneously achieve phytic acid degradation and endogenous enzyme activity retention.

[0065] The superheated steam environment conditions were: pressure 1.0 MPa, temperature 170℃, superheated steam penetration depth 1.3 times the diameter of pea flour particles (controlled by dynamic feedback of infrared thermal imaging; infrared thermal imaging showed the internal temperature gradient ΔT = 8℃ / mm), and the instantaneous phase change explosion treatment time of superheated steam was 20 s; the shear rate of the micron-level shear force was 1.2 × 10⁻⁶. 4 s -1 The porosity of the porous framework network is 68%; the phytic acid degradation rate is 92.3%; and the endogenous enzyme activity is retained at 87.5%.

[0066] (2) Two-enzyme gradient sequential digestion: The product of step (1) is sequentially digested as follows:

[0067] a) High-temperature enzymatic hydrolysis: amylase is used to hydrolyze amylose; the mass ratio of α-amylase to pea flour is 1.25%; the high-temperature enzymatic hydrolysis temperature is 60℃, the time is 30 min, and the pH is 6.8; the degree of hydrolysis is controlled at 42.8%, and the viscosity of the system is reduced to 48 mPa·s.

[0068] b) Low-temperature enzymatic hydrolysis: α-galactosidase is used to target and cleave α-1,6-galactosidic bonds; the mass ratio of α-galactosidase to pea flour is 0.8%; the low-temperature enzymatic hydrolysis temperature is 50℃, the time is 60 min, and the pH is 5; the oligosaccharide residue is 0.35%.

[0069] The switching rate of the two-stage enzymatic hydrolysis temperature was 6℃ / min. Online enzyme activity monitoring showed that the enzyme utilization rates in the two stages were 89.2% and 82.7%, respectively.

[0070] (3) Multi-scale structural composite: The product of step (2) is subjected to extrusion shearing treatment to induce the generation of nanofibers penetrating the microporous skeleton and form a microporous-nanofiber interpenetrating network structure; the screw speed of the extrusion shearing treatment is 350 rpm, the shear stress is 1.8 MPa, and the treatment time is 15 min; the micropore diameter in the nanofiber penetrating microporous skeleton is 82 nm, the water holding capacity of the microporous-nanofiber interpenetrating network structure is 8.8 g / g, and the contact angle is 38°.

[0071] (4) Spray drying: The product from step (3) was spray dried to obtain pea protein powder. The inlet air temperature was 190℃ and the outlet air temperature was 85℃. Detection indicators: solubility index SI = 88.7%, IgE binding activity 0.12 IU / g, and predicted shelf life 19 months.

[0072] The interfacial bonding energy between the nanofibers and the microporous framework in the prepared pea protein powder is 35 mJ / m. 2 The surface water contact angle of the pea protein powder was 38°, the oxidation induction time of the lipid components of the pea protein powder was 46 min, and the digestibility of the pea protein powder was 98%. The masking rate of the allergenic protein epitopes was 90%, and the storage modulus of the obtained pea protein powder was G' = 375 Pa and the loss tangent tanδ = 0.16.

[0073] Through the above meticulous process, we ensure the high quality and convenience of our instant soybean powder, making it an ideal food choice for a fast-paced lifestyle.

[0074] Example 2:

[0075] (1) Superheated steam instantaneous phase change explosion treatment: 10 kg of 100 mesh pea flour is placed in a superheated steam environment. Micron-level shear force is generated by the instantaneous vaporization of liquid water to construct a porous framework network in a directional manner, so as to simultaneously achieve phytic acid degradation and endogenous enzyme activity retention.

[0076] The superheated steam environment conditions were: pressure 1.0 MPa, temperature 170℃, superheated steam penetration depth 1.3 times the diameter of pea flour particles (controlled by dynamic feedback of infrared thermal imaging; infrared thermal imaging showed the internal temperature gradient ΔT = 8℃ / mm), and the instantaneous phase change explosion treatment time of superheated steam was 20 s; the shear rate of the micron-level shear force was 1.2 × 10⁻⁶. 4 s -1 The porosity of the porous framework network is 68%; the phytic acid degradation rate is 92.3%; and the endogenous enzyme activity is retained at 87.5%.

[0077] (2) Two-enzyme gradient sequential digestion: The product of step (1) is sequentially digested as follows:

[0078] a) High-temperature enzymatic hydrolysis: amylase is used to hydrolyze amylose; the mass ratio of α-amylase to pea flour is 1%, the high-temperature enzymatic hydrolysis temperature is 55℃, the time is 25min, and the pH is 6.5; the degree of hydrolysis is controlled at 41.5%, and the viscosity of the system is reduced to 48.5mPa·s;

[0079] b) Low-temperature enzymatic hydrolysis: α-galactosidase is used to target and cleave α-1,6-galactosidic bonds; the mass ratio of α-galactosidase to pea flour is 0.5%; the low-temperature enzymatic hydrolysis temperature is 45℃, the time is 55 min, and the pH is 4.5; the oligosaccharide residue is 0.38%.

[0080] The switching rate of the two-stage enzymatic hydrolysis temperature was 5℃ / min. Online enzyme activity monitoring showed that the enzyme utilization rates in the two stages were 89.2% and 82.7%, respectively.

[0081] (3) Multi-scale structural composite: The product of step (2) is subjected to extrusion shearing treatment to induce the generation of nanofibers penetrating the microporous skeleton and form a microporous-nanofiber interpenetrating network structure; the screw speed of the extrusion shearing treatment is 350 rpm, the shear stress is 1.8 MPa, and the treatment time is 15 min; the micropore diameter in the nanofiber penetrating microporous skeleton is 82 nm, the water holding capacity of the microporous-nanofiber interpenetrating network structure is 8.8 g / g, and the contact angle is 38°.

[0082] (4) Spray drying: The product from step (3) was spray dried to obtain pea protein powder. The inlet air temperature was 180℃ and the outlet air temperature was 80℃. Detection indicators: solubility index SI = 86.5%, IgE binding activity 0.13 IU / g, and predicted shelf life 18.5 months.

[0083] The interfacial bonding energy between the nanofibers and the microporous framework in the prepared pea protein powder is 30 mJ / m. 2The surface water contact angle of the pea protein powder was 38°, the oxidation induction time of the lipid components of the pea protein powder was 42 min, and the digestibility of the pea protein powder was 96%. The masking rate of the allergenic protein epitopes was 87%, and the storage modulus of the obtained pea protein powder was G' = 360 Pa and the loss tangent tanδ = 0.15.

[0084] Example 3:

[0085] (1) Superheated steam instantaneous phase change explosion treatment: 10 kg of 100 mesh pea flour is placed in a superheated steam environment. Micron-level shear force is generated by the instantaneous vaporization of liquid water to construct a porous framework network in a directional manner, so as to simultaneously achieve phytic acid degradation and endogenous enzyme activity retention.

[0086] The superheated steam environment conditions were: pressure 1.2 MPa, temperature 180℃, superheated steam penetration depth 1.5 times the diameter of pea flour particles (controlled by dynamic feedback of infrared thermal imaging; infrared thermal imaging showed the internal temperature gradient ΔT = 8℃ / mm), and the instantaneous phase change explosion treatment time of superheated steam was 25 s; the shear rate of the micron-level shear force was 1.5 × 10⁻⁶. 4 s -1 The porosity of the porous framework network is 70%; the phytic acid degradation rate is 94%; and the endogenous enzyme activity is retained at 86.4%.

[0087] (2) Two-enzyme gradient sequential digestion: The product of step (1) is sequentially digested as follows:

[0088] a) High-temperature enzymatic hydrolysis: amylase is used to hydrolyze amylose; the mass ratio of α-amylase to pea flour is 1.25%, the high-temperature enzymatic hydrolysis temperature is 60℃, the time is 30 min, and the pH is 6.8; the degree of hydrolysis is controlled at 42.8%, and the viscosity of the system is reduced to 48 mPa·s;

[0089] b) Low-temperature enzymatic hydrolysis: α-galactosidase is used to target and cleave α-1,6-galactosidic bonds; the mass ratio of α-galactosidase to pea flour is 0.8%; the low-temperature enzymatic hydrolysis temperature is 50℃, the time is 60 min, and the pH is 5; the oligosaccharide residue is 0.35%.

[0090] The switching rate of the two-stage enzymatic hydrolysis temperature was 6℃ / min. Online enzyme activity monitoring showed that the enzyme utilization rates in the two stages were 89.2% and 82.7%, respectively.

[0091] (3) Multi-scale structural composite: The product of step (2) is subjected to extrusion shearing treatment to induce the generation of nanofibers penetrating the microporous skeleton and form a microporous-nanofiber interpenetrating network structure; the screw speed of the extrusion shearing treatment is 300 rpm, the shear stress is 1.5 MPa, and the treatment time is 10 min; the micropore diameter in the nanofiber penetrating microporous skeleton is 75 nm, the water holding capacity of the microporous-nanofiber interpenetrating network structure is 8.5 g / g, and the contact angle is 30°.

[0092] (4) Spray drying: The product from step (3) was spray dried to obtain pea protein powder. The inlet air temperature was 200℃ and the outlet air temperature was 90℃. Detection indicators: solubility index SI = 87.2%, IgE binding activity 0.125 IU / g, and predicted shelf life 18.7 months.

[0093] The interfacial bonding energy between the nanofibers and the microporous framework in the prepared pea protein powder is 34 mJ / m. 2 The surface water contact angle of the pea protein powder was 30°, the oxidation induction time of the lipid components of the pea protein powder was 45 min, and the digestibility of the pea protein powder was 97%. The masking rate of the allergenic protein epitopes was 89%, and the storage modulus of the obtained pea protein powder was G' = 370 Pa and the loss tangent tanδ = 0.16.

[0094] Example 4:

[0095] (1) Superheated steam instantaneous phase change explosion treatment: 10 kg of 100 mesh pea flour is placed in a superheated steam environment. Micron-level shear force is generated by the instantaneous vaporization of liquid water to construct a porous framework network in a directional manner, so as to simultaneously achieve phytic acid degradation and endogenous enzyme activity retention.

[0096] The superheated steam environment conditions were: pressure 1.0 MPa, temperature 170℃, superheated steam penetration depth 1.3 times the diameter of pea flour particles (controlled by dynamic feedback of infrared thermal imaging; infrared thermal imaging showed the internal temperature gradient ΔT = 8℃ / mm), and the instantaneous phase change explosion treatment time of superheated steam was 20 s; the shear rate of the micron-level shear force was 1.2 × 10⁻⁶. 4 s -1 The porosity of the porous framework network is 68%; the phytic acid degradation rate is 92.3%; and the endogenous enzyme activity is retained at 87.5%.

[0097] (2) Two-enzyme gradient sequential digestion: The product of step (1) is sequentially digested as follows:

[0098] a) High-temperature enzymatic hydrolysis: amylase is used to hydrolyze amylose; the mass ratio of α-amylase to pea flour is 1%, the high-temperature enzymatic hydrolysis temperature is 55℃, the time is 25min, and the pH is 6.5; the degree of hydrolysis is controlled at 41.5%, and the viscosity of the system is reduced to 48.5mPa·s;

[0099] b) Low-temperature enzymatic hydrolysis: α-galactosidase is used to target and cleave α-1,6-galactosidic bonds; the mass ratio of α-galactosidase to pea flour is 0.5%; the low-temperature enzymatic hydrolysis temperature is 45℃, the time is 55 min, and the pH is 4.5; the oligosaccharide residue is 0.38%.

[0100] The switching rate of the two-stage enzymatic hydrolysis temperature was 5℃ / min. Online enzyme activity monitoring showed that the enzyme utilization rates in the two stages were 89.2% and 82.7%, respectively.

[0101] (3) Multi-scale structural composite: The product of step (2) is subjected to extrusion shearing treatment to induce the generation of nanofibers penetrating the microporous skeleton and form a microporous-nanofiber interpenetrating network structure; the screw speed of the extrusion shearing treatment is 300 rpm, the shear stress is 1.5 MPa, and the treatment time is 10 min; the micropore diameter in the nanofiber penetrating microporous skeleton is 75 nm, the water holding capacity of the microporous-nanofiber interpenetrating network structure is 8.5 g / g, and the contact angle is 30°.

[0102] (4) Spray drying: The product from step (3) was spray dried to obtain pea protein powder. The inlet air temperature was 180℃ and the outlet air temperature was 80℃. Detection indicators: solubility index SI = 86.5%, IgE binding activity 0.13 IU / g, and predicted shelf life 18.5 months.

[0103] The interfacial bonding energy between the nanofibers and the microporous framework in the prepared pea protein powder is 28 mJ / m. 2 The surface water contact angle of the pea protein powder was 30°, the oxidation induction time of the lipid components of the pea protein powder was 40 min, and the digestibility of the pea protein powder was 93.2%. The masking rate of the allergenic protein epitopes was 85%, and the storage modulus of the obtained pea protein powder was G' = 340 Pa and the loss tangent tanδ = 0.14.

[0104] Example 5:

[0105] (1) Superheated steam instantaneous phase change explosion treatment: 10 kg of 100 mesh pea flour is placed in a superheated steam environment. Micron-level shear force is generated by the instantaneous vaporization of liquid water to construct a porous framework network in a directional manner, so as to simultaneously achieve phytic acid degradation and endogenous enzyme activity retention.

[0106] The superheated steam environment conditions were: pressure 0.8 MPa, temperature 160℃, superheated steam penetration depth 1.3 times the diameter of pea flour particles (controlled by dynamic feedback of infrared thermal imaging; infrared thermal imaging showed the internal temperature gradient ΔT = 8℃ / mm), and the instantaneous phase change explosion treatment time of superheated steam was 18 s; the shear rate of the micron-level shear force was 1.2 × 10⁻⁶. 4 s-1 The porosity of the porous framework network is 66.5%; the phytic acid degradation rate is 90.8%; and the endogenous enzyme activity is retained at 88.5%.

[0107] (2) Two-enzyme gradient sequential digestion: The product of step (1) is sequentially digested as follows:

[0108] a) High-temperature enzymatic hydrolysis: amylase is used to hydrolyze amylose; the mass ratio of α-amylase to pea flour is 1%, the high-temperature enzymatic hydrolysis temperature is 55℃, the time is 25min, and the pH is 6.5; the degree of hydrolysis is controlled at 41.5%, and the viscosity of the system is reduced to 48.5mPa·s;

[0109] b) Low-temperature enzymatic hydrolysis: α-galactosidase is used to target and cleave α-1,6-galactosidic bonds; the mass ratio of α-galactosidase to pea flour is 0.5%; the low-temperature enzymatic hydrolysis temperature is 45℃, the time is 55 min, and the pH is 4.5; the oligosaccharide residue is 0.38%.

[0110] The switching rate of the two-stage enzymatic hydrolysis temperature was 5℃ / min. Online enzyme activity monitoring showed that the enzyme utilization rates in the two stages were 89.2% and 82.7%, respectively.

[0111] (3) Multi-scale structural composite: The product of step (2) is subjected to extrusion shearing treatment to induce the generation of nanofibers penetrating the microporous skeleton and form a microporous-nanofiber interpenetrating network structure; the screw speed of the extrusion shearing treatment is 350 rpm, the shear stress is 1.8 MPa, and the treatment time is 15 min; the micropore diameter in the nanofiber penetrating microporous skeleton is 82 nm, the water holding capacity of the microporous-nanofiber interpenetrating network structure is 8.8 g / g, and the contact angle is 38°.

[0112] (4) Spray drying: The product from step (3) was spray dried to obtain pea protein powder. The inlet air temperature was 180℃ and the outlet air temperature was 80℃. Test indicators: solubility index SI = 86.5%, IgE binding activity 0.13 IU / g, and predicted shelf life 18.5 months. The interfacial bonding energy between the nanofibers and the microporous framework in the obtained pea protein powder was 27 mJ / m. 2 The surface water contact angle of the pea protein powder was 38°, the oxidation induction time of the lipid components of the pea protein powder was 38 min, and the digestibility of the pea protein powder was 90%. The masking rate of the allergenic protein epitopes was 84%, and the storage modulus of the obtained pea protein powder was G' = 330 Pa and the loss tangent tanδ = 0.13.

[0113] Example 6:

[0114] (1) Superheated steam instantaneous phase change explosion treatment: 10 kg of 100 mesh pea flour is placed in a superheated steam environment. Micron-level shear force is generated by the instantaneous vaporization of liquid water to construct a porous framework network in a directional manner, so as to simultaneously achieve phytic acid degradation and endogenous enzyme activity retention.

[0115] The superheated steam environment conditions were: pressure 0.8 MPa, temperature 160℃, superheated steam penetration depth 1.3 times the diameter of pea flour particles (controlled by dynamic feedback of infrared thermal imaging; infrared thermal imaging showed the internal temperature gradient ΔT = 8℃ / mm), and the instantaneous phase change explosion treatment time of superheated steam was 18 s; the shear rate of the micron-level shear force was 1.2 × 10⁻⁶. 4 s -1 The porosity of the porous framework network is 66.5%; the phytic acid degradation rate is 90.8%; and the endogenous enzyme activity is retained at 88.5%.

[0116] (2) Two-enzyme gradient sequential digestion: The product of step (1) is sequentially digested as follows:

[0117] a) High-temperature enzymatic hydrolysis: amylase is used to hydrolyze amylose; the mass ratio of α-amylase to pea flour is 1.25%, the high-temperature enzymatic hydrolysis temperature is 60℃, the time is 30 min, and the pH is 6.8; the degree of hydrolysis is controlled at 42.8%, and the viscosity of the system is reduced to 48 mPa·s;

[0118] b) Low-temperature enzymatic hydrolysis: α-galactosidase is used to target and cleave α-1,6-galactosidic bonds; the mass ratio of α-galactosidase to pea flour is 0.8%; the low-temperature enzymatic hydrolysis temperature is 50℃, the time is 60 min, and the pH is 5; the oligosaccharide residue is 0.35%.

[0119] The switching rate of the two-stage enzymatic hydrolysis temperature was 6℃ / min. Online enzyme activity monitoring showed that the enzyme utilization rates in the two stages were 89.2% and 82.7%, respectively.

[0120] (3) Multi-scale structural composite: The product of step (2) is subjected to extrusion shearing treatment to induce the generation of nanofibers penetrating the microporous skeleton and form a microporous-nanofiber interpenetrating network structure; the screw speed of the extrusion shearing treatment is 300 rpm, the shear stress is 1.5 MPa, and the treatment time is 10 min; the micropore diameter in the nanofiber penetrating microporous skeleton is 75 nm, the water holding capacity of the microporous-nanofiber interpenetrating network structure is 8.5 g / g, and the contact angle is 30°.

[0121] (4) Spray drying: The product from step (3) was spray dried to obtain pea protein powder. The inlet air temperature was 200℃ and the outlet air temperature was 90℃. Detection indicators: solubility index SI = 87.2%, IgE binding activity 0.125 IU / g, and predicted shelf life 18.7 months.

[0122] The interfacial bonding energy between the nanofibers and the microporous framework in the prepared pea protein powder is 33 mJ / m. 2 The surface water contact angle of the pea protein powder was 30°, the oxidation induction time of the lipid components of the pea protein powder was 44 min, and the digestibility of the pea protein powder was 96.3%. The masking rate of the allergenic protein epitopes was 88%, and the storage modulus of the obtained pea protein powder was G' = 368 Pa and the loss tangent tanδ = 0.15.

[0123] Comparative Example 1:

[0124] Based on Example 1, the explosion treatment in step (1) is cancelled, and the process proceeds directly to double enzymatic hydrolysis and structural recombination.

[0125] The interfacial bonding energy between the nanofibers and the microporous framework in the prepared pea protein powder is 18 mJ / m. 2 The surface water contact angle of the pea protein powder was 52°, the oxidation induction time of the lipid components of the pea protein powder was 28 min, and the digestibility of the pea protein powder was 84.3%. The masking rate of the allergenic protein epitopes was 66%, and the storage modulus of the obtained pea protein powder was G' = 210 Pa and the loss tangent tanδ = 0.24.

[0126] Comparative Example 2:

[0127] Based on Example 1, the low-temperature enzymatic hydrolysis with α-galactosidase was omitted, and only the high-temperature enzymatic hydrolysis with α-amylase was retained. The α-amylase hydrolysis conditions remained unchanged (60℃, 30 min, pH 6.8, enzyme dosage 1.25%). No α-galactosidase treatment was performed.

[0128] The interfacial bonding energy between the nanofibers and the microporous framework in the prepared pea protein powder is 27 mJ / m. 2 The surface water contact angle of the pea protein powder was 46°, the oxidation induction time of the lipid components of the pea protein powder was 35 min, and the digestibility of the pea protein powder was 88.7%. The masking rate of the allergenic protein epitopes was 70%, and the storage modulus of the obtained pea protein powder was G' = 260 Pa and the loss tangent tanδ = 0.21.

[0129] Comparative Example 3:

[0130] Based on Example 1, this comparative example completely omits the multi-scale structural composite (step 3), that is, it does not perform screw extrusion and shearing, but directly performs spray drying after enzymatic hydrolysis, in order to evaluate the necessity of the structure construction step.

[0131] The interfacial bonding energy between the nanofibers and the microporous framework in the prepared pea protein powder was 21 mJ / m. 2The surface water contact angle of the pea protein powder was 45°, the oxidation induction time of the lipid components of the pea protein powder was 31 min, and the digestibility of the pea protein powder was 86.1%. The masking rate of the allergenic protein epitope was 72%, and the storage modulus of the obtained pea protein powder was G' = 235 Pa and the loss tangent tanδ = 0.22.

[0132] The data shows that the pea protein powder obtained by the method and parameters of Example 1 has the best effect.

[0133] Table 1. Solubility and sensory evaluation of instant soybean powder obtained from different process combinations.

[0134]

[0135] Table 2. Solubility and sensory evaluation of instant soybean powder obtained by different processing methods.

[0136]

[0137] The observation and evaluation results are shown in Tables 1 and 2. Figure 1 As can be seen from the table, the instant pea powder of Examples 1-6 of this invention dissolves quickly and has good solubility. It does not easily clump when brewed and can form a uniform and smooth pea powder in 15-30 seconds. Compared with Example 1, the dissolution time of Comparative Examples 1-3 is longer, and Comparative Example 3 has slight clumping and poor sensory quality. The instant pea powder prepared by this invention has a uniform color, is light yellow or pale yellow, has a rich pea aroma, and has no fishy smell. The pea powder formed after brewing is delicate and smooth, melts in the mouth, and has no grainy texture. At the same time, this product is easy to eat, requires no cooking, and combines the traditional flavor with the convenience and high quality of modern food.

Claims

1. A method for high-value preparation of pea protein based on the synergistic effect of molecular-level structure regulation and enzymatic hydrolysis targeting, characterized in that: The raw material is 100% pea flour, and the process includes the following steps: (1) Superheated steam instantaneous phase change explosion treatment: Pea flour is placed in a superheated steam environment, and micron-level shear force is generated by the instantaneous vaporization of liquid water to construct a porous framework network in a directional manner, so as to simultaneously achieve phytic acid degradation and retention of endogenous enzyme activity. (2) Two-enzyme gradient sequential digestion: The product of step (1) is sequentially digested as follows: a) High-temperature enzymatic hydrolysis: Hydrolyzing amylose using α-amylase; b) Low-temperature enzymatic hydrolysis: α-galactosidase is used to target and cleave α-1,6-galactosidic bonds. (3) Multiscale structural composite: The product of step (2) is subjected to extrusion and shearing treatment to induce the generation of nanofibers that penetrate the microporous skeleton, forming a microporous-nanofiber interpenetrating network structure. (4) Spray drying: The product from step (3) is spray dried to obtain pea protein powder.

2. The method for high-value preparation of pea protein based on molecular-level structure regulation and enzymatic targeted hydrolysis according to claim 1, characterized in that: In step (1), the superheated steam environment conditions are: pressure 0.8-1.2 MPa, temperature 160-180℃, superheated steam penetration depth 1.2-1.5 times the diameter of pea flour particles, and superheated steam instantaneous phase change explosion treatment time 15-25 s; the shear rate of micron-level shear force ≥10 4 s -1 The porosity of the porous framework network is 60-70%; the phytic acid degradation rate is ≥90%; and the endogenous enzyme activity retention is ≥85%.

3. The method for high-value preparation of pea protein based on molecular-level structure regulation and targeted enzymatic hydrolysis according to claim 1, characterized in that: In step (2), the high-temperature enzymatic hydrolysis temperature is 55-65℃, the time is 25-35min, and the pH is 6.5-7.0; the degree of hydrolysis is controlled to be ≥40%, and the system viscosity is reduced to <50mPa·s; the low-temperature enzymatic hydrolysis temperature is 45-55℃, the time is 55-75min, and the pH is 4.5-5.5; the mass ratio of α-amylase to pea flour is 1:100-1:80, and the mass ratio of α-galactosidase to pea flour is 1:200-1:125; the switching rate of the two enzymatic hydrolysis temperatures is 5-8℃ / min.

4. The method for high-value preparation of pea protein based on molecular-level structure regulation and enzymatic targeted hydrolysis according to claim 1, characterized in that: In step (3), the screw speed of the extrusion shearing treatment is 300-400 rpm, the shear stress is 1.5-2.0 MPa, and the treatment time is 10-15 min; the diameter of the micropores in the nanofiber penetrating microporous skeleton is 50-100 nm, and the water holding capacity of the micropore-nanofiber interpenetrating network structure is ≥8 g / g.

5. The method for high-value preparation of pea protein based on molecular-level structure regulation and enzymatic targeted hydrolysis according to claim 1, characterized in that: In step (4), the inlet air temperature for drying is 180-200℃ and the outlet air temperature is 80-90℃.

6. The method for high-value preparation of pea protein based on molecular-level structure regulation and enzymatic targeted hydrolysis according to claim 1, characterized in that: The interfacial bonding energy between the nanofibers and the microporous framework in the prepared pea protein powder is 25-35 mJ / m. 2 The surface water contact angle of the pea protein powder is 15-40°, the oxidation induction time of the lipid components of the pea protein powder is 30-50 min, the solubility index (SI) of the pea protein powder is ≥85%, the digestibility of the pea protein powder is ≥90%, the epitope masking rate of the sensitized protein is ≥80%, the IgE binding activity is <0.15 IU / g, and the storage modulus of the obtained pea protein powder is G'=350±50Pa and the loss tangent tanδ=0.12-0.

18.

7. A system for realizing the high-value preparation method of pea protein based on the synergistic effect of molecular-level structure regulation and enzymatic hydrolysis targeting as described in any one of claims 1-6, characterized in that, The system includes a steam phase change control module, an enzymatic hydrolysis timing control module, a co-rotating twin-screw extruder, and a spray drying device.

8. The system according to claim 7, characterized in that, The steam phase change control module is used to realize the directional construction of porous structures, integrating a feed inlet (101), a condensate outlet (102), a secondary steam outlet (103), an evaporation chamber (104), a heating steam inlet (105), a heating chamber (106), and a discharge outlet (107); the feed inlet (101) is located at the bottom of the evaporation chamber (104) for quantitatively introducing pea flour material; the secondary steam outlet (103) is located at the top of the evaporation chamber (104) for discharging the secondary steam generated by evaporation; the heating chamber (106) is located below the evaporation chamber (104), and the two are connected. The heating chamber (106) is used to contain superheated steam and provide phase change heat transfer heat; the heating steam... The inlet (105) is located at the top of the heating chamber (106) and is connected to the heating steam of the external steam pipeline network; the condensate outlet (102) and the discharge port (107) are located at the bottom of the heating chamber (106) and are used to discharge condensate and the material after evaporation, concentration and porous structure regulation, respectively; the discharge port (107) is connected to the inlet of the enzymatic hydrolysis timing control module; the material to be processed enters the evaporation chamber (104) from the feed inlet (101), the external heating steam enters the heating chamber (106) through the heating steam inlet (105), and the evaporation is driven by heat exchange. The generated secondary steam is discharged through the secondary steam outlet (103), and the final product is discharged from the evaporation chamber (104) through the discharge port (107); The enzymatic hydrolysis timing control module adopts a concentric cylindrical dual-temperature zone reaction tower to overcome competitive inhibition: the central high-temperature zone (202) has a built-in high-temperature filling layer (203), and the outer low-temperature zone (206) wraps around the central high-temperature zone (202) and has a built-in low-temperature filling layer (205). The two zones are physically isolated by a thermal barrier partition (204). The feed inlet is located at the top of the high-temperature zone (202) and is connected to the material outlet of the steam phase change control module. After the reaction in the central high-temperature zone (202), the material enters the low-temperature filling layer (205) through the central channel of the thermal barrier partition (204) and is finally discharged to the co-rotating twin-screw extruder from the bottom outlet of the low-temperature zone (206). The co-rotating twin-screw extruder is used to construct a microporous-nanofiber interpenetrating network structure. It includes a co-rotating twin-screw body (301), a drive device (302), a co-rotating twin-screw extruder inlet (303), and a co-rotating twin-screw extruder outlet (304). The co-rotating twin-screw extruder inlet (303) and the co-rotating twin-screw extruder outlet (304) are respectively located at both ends of the co-rotating twin-screw extruder. The co-rotating twin-screw extruder outlet (304) is connected to a spray drying device. The co-rotating twin screws are arranged horizontally side by side in the central axial direction of the co-rotating twin-screw extruder. The co-rotating twin screws are driven to rotate by the drive device (302) and break down protein aggregates by mechanical shear force.

9. The system according to claim 8, characterized in that, In the early stage of using the steam phase change control module, before the pea flour material is introduced, the condensate generated by the temperature difference in the heating chamber (106) and evaporation chamber (104) after the heating steam inlet (105) enters the heating chamber (106) and evaporation chamber (104) is discharged through the condensate outlet (102). After the temperature of the heating chamber (106) and evaporation chamber (104) rises to the steam temperature, no condensate is generated, and then the pea flour material is introduced from the feed inlet (101). In the enzymatic hydrolysis timing control module, the temperature sensor (201) and enzyme activity probe are connected to the high-temperature filling layer (203) and the low-temperature filling layer (205) respectively, for real-time monitoring of temperature parameters, α-amylase and α-galactosidase activities; pH adaptive adjustment unit Buffer solution is injected into the high-temperature filling layer (203) and the low-temperature filling layer (205) through a ring pipe (response ≤ 5 seconds). The control panel (207) works with the sensor (201), enzyme activity probe, and pH adaptive adjustment unit to achieve precise control of the dual temperature zones. The heat barrier partition (204) is a vacuum insulation layer with a high-temperature resistant ceramic coating on both sides to ensure a temperature difference ≥ 10℃. The high-temperature filling layer (203) is made of 316L stainless steel with a pore size of 0.5-1mm, and the low-temperature filling layer (205) is made of PTFE with a pore size of 0.2-0.5mm. The length-to-diameter ratio of the co-rotating twin-screw body (301) in the co-rotating twin-screw extruder is 40:1, and the applicable diameter is 70-80mm.

10. The use of the pea protein powder prepared by the method according to any one of claims 1-6 in the preparation of infant complementary foods, elderly nutritional products, or functional foods, characterized in that: The pea protein powder can be rehydrated to form a stable colloid with a solids content of 15-25% and a shelf life of more than 18 months.

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