Functional extraction of protein

Abstract

The present disclosure relates to a method for producing functional proteins, and in particular, functional soy protein concentrate (FSPC). This method bypasses the multi-step processes of conventional techniques by integrating the functionalization step directly into the alcohol extraction process. The process involves treating a protein source, such as soy white flakes or soy protein concentrate powder, with an alcohol solution comprising alcohol, an alkali hydroxide, and a reducing agent. This treatment process eliminates the need for separate hydration, pH adjustment, high-temperature short-time (HTST) treatment, and separate drying steps, notably removing spray drying in general. This disclosure also encompasses the functional soy protein produced by the disclosed method and its use in various food applications.

Description

FUNCTIONAL EXTRACTION OF PROTEINCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of priority of U.S. Provisional Application No. 63 / 662,670, filed June 21 , 2024, the contents of which are hereby expressly incorporated by reference in their entirety.FIELD OF THE INVENTION

[0002] The present disclosure relates to methods for producing functional soy protein concentrate (FSPC) with enhanced properties. It further relates to the FSPC produced by the disclosed methods and its use in various food applications, such as plant-based meat alternatives and other alternative protein products.BACKGROUND OF THE INVENTION

[0003] Traditionally, soy protein is incorporated into food products in various forms, ranging from soy flour to soy protein concentrate (SPC) and isolate. While soy flour, derived directly from defatted soy flakes, contains approximately 50% protein, SPC and isolates undergo further processing to achieve higher protein concentrations. SPC, typically containing around 70% protein, is produced through aqueous alcohol extraction or pH-adjusted water washing. Soy protein isolate, with a protein content exceeding 90%, necessitates a more complex alkaline extraction followed by acid precipitation. However, for many meat-analog applications, the high protein content of isolate is not required, making SPC a more cost-effective alternative.

[0004] Standard methods for producing functional SPC, which is valued for its enhanced viscosity and gelling capabilities, rely on a multi-step process. This typically involves dispersing SPC in water, adjusting the pH with alkaline solutions like potassium or sodium hydroxide, and adding metabisulfite to control color and cross-linking. The process critically depends on a High Temperature Short Time (HTST) heat treatment step, followed by spray drying to achieve the desired moisture content and particle size. Although effective, this conventional approach has several drawbacks, including high water and energy consumption, the requirement for specialized equipment like spray dryers, and potential negative impacts on product color and flavor due to the intensive heat treatment.

[0005] The present invention provides a simplified and more sustainable method for producing functionalized protein concentrates and isolates. By leveraging a novel functionalextraction process, the invention eliminates the need for both the HTST and spray drying steps. This streamlined approach offers numerous advantages, including reduced water and energy usage, lower capital expenditures by eliminating the need for specialized equipment, and the potential for improved product quality with respect to color and flavor.SUMMARY OF THE INVENTION

[0006] Disclosed herein is a method for producing functional soy protein powder, the method comprising: (a) treating a soy protein source comprising soy flakes or soy protein concentrate powder with an alcohol solution comprising alcohol, an alkali hydroxide, and a reducing agent to obtain a functionalized protein fraction; (b) drying the functionalized protein fraction to obtain a dried functionalized protein; and (c) grinding the dried protein to obtain a functional soy protein powder.

[0007] Afunctional soy protein produced by the above-described method is also provided.

[0008] Further disclosed is a method for improving at least one functional property of soy protein, the method comprising: (a) adding an alkali hydroxide and a sulfite salt to an aqueous alcohol solution comprising from about 50% to about 99.95% alcohol by volume based on the total volume of the aqueous alcohol solution; (b) treating a soy protein source comprising white flakes or soy protein concentrate powder with the aqueous alcohol solution of step (a); and (c) drying the treated protein solution to obtain a functional soy protein concentrate, wherein the at least one functional property is selected from the group consisting of increased viscosity, enhanced gelling characteristics, and improved emulsification properties compared to the untreated soy protein source.BRIEF DESCRIPTION OF DRAWINGS

[0009] FIG. 1 is a photograph of the jacketed lab reactor used in the Examples.

[0010] FIG. 2 is a graph illustrating the rapid visco analysis (RVA) profiles of soy protein concentrate (SPC) treated with 0%, 0.15%, and 1 % NaOH, respectively.

[0011] FIG. 3 is a photograph showing the color of the SPC treated with 0%, 0.15% and 1 %NaOH.

[0012] FIG. 4 is a graph showing the RVA curves of SPC treated with varying levels of NaOH (0%, 0.05%, and 0.10%).

[0013] FIG. 5 is a graph comparing the RVA curves of SPC treated with varying levels ofNaOH (0%, 0.05%, and 0.10%) to commercially available functional SPCs.

[0014] FIG. 6A is a bar chart comparing the gelling properties of SPC treated with varying levels of NaOH (0%, 0.05%, and 0.10%) to commercially available functional SPCs.

[0015] FIG. 6B is a bar chart comparing the emulsion properties of SPC treated with varying levels of NaOH (0%, 0.05%, and 0.10%) to commercially available functional SPCs.

[0016] FIG. 7 is a graph depicting the RVA curves of SPC treated with different levels of KOH (0.05% and 0.1%).

[0017] FIG. 8 is a graph comparing the RVA curves of SPC treated with different levels of KOH (0.05% and 0.1 %) to commercially available functional SPCs.

[0018] FIG. 9 is a graph illustrating the RVA curves of SPC produced using different starting materials (white flakes vs. SPC powder) and treated with 0.1 % NaOH.

[0019] FIG. 10 is a graph comparing the RVA curves of SPC produced using different starting materials (white flakes vs. SPC powder) and treated with 0.1 % NaOH to commercially available functional SPCs.

[0020] FIG. 11 is a graph showing the RVA curves of SPC treated with 0.1% NaOH and varying levels of sodium metabisulfite (0.0%, 0.05%, and 0.1 %).

[0021] FIG. 12 is a graph comparing the RVA curves of SPC treated with 0.1 % NaOH and varying levels of sodium metabisulfite (0.0%, 0.05%, and 0.1 %) to commercially available functional SPCs.

[0022] FIG. 13 is a bar chart comparing the emulsion properties of SPC treated with 0.1 % NaOH and varying levels of sodium metabisulfite (0.0%, 0.05%, and 0.1 %) to commercially available functional SPCs.

[0023] FIG. 14 is a graph showing the RVA curves of SPC treated with 0.1 % NaOH, 0.1% sodium metabisulfite, and subjected to different final wash procedures (control, 99.7% ethanol wash, 88.0% ethanol wash, and 70% ethanol wash).

[0024] FIG. 15 is a graph comparing the RVA curves of SPC treated with 0.1 % NaOH, 0.1 % sodium metabisulfite, and subjected to different final wash procedures (control, 99.7% ethanol wash, 88.0% ethanol wash, and 70% ethanol wash) to commercially available functional SPCs.

[0025] FIG. 16 is a bar chart comparing the emulsion properties of SPC treated with 0.1 % NaOH, 0.1 % sodium metabisulfite, and subjected to different final wash procedures (control, 99.7% ethanol wash, 88.0% ethanol wash, and 70% ethanol wash).

[0026] FIG. 17 is a graph showing the RVA curve profiles at 75 °C of SPC treated with 0.1% NaOH and 0.1 % NaMBS under 60% and 70% ethanol washing concentrations, compared to commercial standards.

[0027] FIG. 18 is a graph showingthe RVA curve profiles at 130 °C of SPC treated with 0.1%NaOH and 0.1 % NaMBS under 60% and 70% ethanol washing concentrations, compared to commercial standards.

[0028] FIG. 19 is a graph showingthe RVA curve profiles of at 75 °C of SPC treated with 0.1 %NaOH in 70% ethanol solution, comparing bench-scale and pilot-scale processes to market standards.

[0029] FIG. 20 is a graph showingthe RVA curve profiles at 130 °C of SPC treated with 0.1%NaOH in 70% ethanol solution, comparing bench-scale and pilot-scale processes to market standards.

[0030] FIG. 21 is a graph showing protein content and PDI results of SPC treated with 0.1 % NaOH in 70% ethanol solution, comparing bench-scale and pilot-scale processes to market standards.

[0031] FIG. 22 is a bar graph showing emulsion strength results at 25 mm after cooking ofSPC treated with 0.1 % NaOH in 70% ethanol solution, comparing bench-scale and pilot-scale processes to market standards.

[0032] FIG. 23 is a graph showingthe RVA curve profiles at 75 °C of SPC treated with 0.1% NaOH and 0.1 % NaMBS using different particle size distributions (natural and #12 sieve) compared to commercial samples.

[0033] FIG. 24 is a graph showingthe RVA curve profiles at 130 °C of SPC treated with 0.1% NaOH and 0.1 % NaMBS using different particle size distributions (natural and #12 sieve) compared to commercial samples.

[0034] FIG. 25 is a graph showing the protein content and PDI results of SPC treated with 0.1 % NaOH in 70% ethanol solution at different extraction temperatures (45 °C and 65 °C) compared to commercial standards.

[0035] FIG. 26 is a graph showing the emulsion strength results of SPC treated with 0.1% NaOH in 70% ethanol solution at different extraction temperatures (45 °C and 65 °C) compared to commercial standards.

[0036] FIG. 27 is a graph showing the protein content and PDI results of SPC treated with 0.1 % NaOH in 70% ethanol solution using different solvent-to-flake ratios (27:1 , 13:1 , and 7:1) compared to commercial standards.

[0037] FIG. 28 is a graph showing the emulsion strength results of SPC treated with 0.1% NaOH in 70% ethanol solution using different solvent-to-flake ratios (27:1 , 13:1 , and 7:1 ) compared to commercial standards.

[0038] FIG. 29 is a graph showing the protein content and PDI results of SPC treated with 0.1 % NaOH in 70% ethanol solution using different retention times (65, 90, and 120 minutes) compared to commercial standards.

[0039] FIG. 30 is a graph showing the emulsion strength results of SPC treated with 0.1% NaOH in 70% ethanol solution using different retention times (65, 90, and 120 minutes) compared to commercial standards.

[0040] FIG. 31 is a schematic layout of a two-extractor system employed on co-current and counter-current extractions, showing the flow of white flakes and solvent.

[0041] FIG. 32 is a diagram illustrating the concentration profile of NaOH and ethanol in the co-current and counter-current extractions.DETAILED DESCRIPTION OF THE INVENTION

[0042] Disclosed herein is an improved method for obtaining a functional protein powder.

[0043] As used herein, the term “about” when used to modify a number means the number plus or minus 10%, preferably 5% or more preferably 2% of the recited value. Recitation of a value in a claim means about that value, where legally permissible. The use of “about” in a claim or in the specification does not limit the full scope of covered equivalents.

[0044] The term “functionalized protein” refers to a protein that has been treated, either physically or chemically, to enhance its functional properties. Such treatment modifies the protein’s structure is manipulated, resulting in improved gelling, viscosity, emulsification, and solubility characteristics compared to untreated or non-functionalized protein.

[0045] The term “protein concentrate,” such as “soy protein concentrate,” refers to a product derived from a protein source (e.g., soybeans), in which the protein content has been increased through the removal of certain components like carbohydrates. Protein concentrates generally have a protein content ranging from about 60% to about 80%.

[0046] The term “protein isolate,” such as “soy protein isolate,” represents a further refined product with an even higher protein concentration, typically exceeding about 90%. Isolates are produced through processing methods that remove nearly all non-protein components.

[0047] The term “reducing agent” refers to a substance that donates electrons to another chemical species in a redox reaction, causing the other species to be reduced. In the context of protein chemistry, reducing agents can break disulfide bonds within protein molecules, thereby influencing their structure and functional properties.

[0048] The term “gel strength” refers to the ability of a protein, upon hydration and heating, to form a firm, cohesive gel. Gel strength is typically measured using a texture analyzer with a suitableprobe. The force required to penetrate the gel to a specific depth is recorded as the “gel strength” and expressed in grams (g).

[0049] The term “emulsion strength” refers to the ability of a protein to stabilize oil-in-water emulsions and prevent separation. It is typically measured using a texture analyzer with a suitable probe. The maximum force required to breakthe emulsion is recorded as the “emulsion strength” and expressed in grams (g).

[0050] The term “protein dispersibility index” or “PDI” refers to the amount of dispersible (soluble) protein relative to the overall amount of protein within a material. PDI may be measured according to AOCS Standard Procedure Ba 10b-09 Protein Dispersibility Index.

[0051] The term “rapid visco analysis” or “RVA” refers to a technique used to analyze the viscosity of a sample, such as a protein solution or slurry, over time and under varying temperature characteristics. RVA involves measuring the resistance of the sample to stirring or rotation using a Rapid Visco Analyzer. Data generated from an RVA can provide insights into the functional properties of ingredients, including gelatinization, pasting, and cooking behavior.

[0052] The use of singular articles such as “a,” “an,” and “the,” and the term “said” are intended to encompass one or more of the recited elements. The terms “comprising,” “including,” and “having” are intended to be inclusive and mean that there may be additional elements other than the listed elements.

[0053] Commercially available functional soy protein concentrates (FSPC) are typically produced from ethanol-extracted or pH-adjusted, water-extracted soy white flakes. These starting materials require a multi-step process to achieve the desired functionality for food applications. This conventional FSPC production process involves extracting soy protein from defatted soy flakes using an aqueous ethanol solution, separating the protein from other components such as carbohydrates and fiber. The protein solution is then vacuum dried to remove the ethanol and concentrate the protein, often under controlled temperature and pressure to maintain protein integrity. The resulting protein concentrate, often a paste, is dispersed in water at a specific ratio to form a slurry, which is then functionalized. Functionalization typically involves pH adjustment with an alkaline solution such as sodium hydroxide (NaOH) or potassium hydroxide (KOH), a critical step in affecting protein solubility and functionality. Sodium metabisulfite (NaMBS), a reducing agent, is added to the slurry primarily to control microbial growth and prevent discoloration during subsequent heat treatment.

[0054] The slurry is then subjected to a high-temperature short-time (HTST) treatment, typically at temperatures between 130 °C and 160 °C for 30 seconds to five minutes. This heat treatment denatures the protein and develops desirable functional characteristics, like gelling capacity, viscosity, foaming, and emulsification. Following HTST treatment, the slurry is spray driedto remove excess water and produce a stable, powdered FSPC product with the desired moisture content and particle size. Finally, the dried FSPC may be ground to achieve the desired particle size distribution, packaged, and distributed for use in various food applications.

[0055] This multi-step process, while effective, has several drawbacks. The multiple processing steps introduce complexity and require specialized equipment, stringent process control, and increased operational costs. The drying steps (vacuum and spray drying), hydration step, and HTST heating require substantial water and energy, resulting in a larger environmental footprint. The high temperatures of HTST treatment, while necessary for functionality development, can negatively impact product quality by causing undesirable color changes (e.g., due to caramelization of residual sugars) and potentially altering flavor.

[0056] The present invention provides a novel and simplified method for producing functional soy protein concentrate (FSPC) with enhanced properties, addressing the limitations of conventional methods. By integrating functionalization directly into the ethanol extraction process, the invention eliminates the need for separate hydration, pH adjustment, HTST treatment, and spray drying steps, resulting in a streamlined process flow.

[0057] The disclosed method involves treating a soy protein source, such as soy white flakes or SPC powder, with an alcohol solution containing an alkali hydroxide and a reducing agent. This single-step treatment simultaneously extracts and functionally modifies the protein, resulting in a product with superior gelling, viscosity, and emulsification properties, and significantly simplifies the production process.

[0058] This method presents several key advantages over conventional FSPC production. Consolidating multiple processing steps into a single treatment reduces complexity, equipment requirements, and operational costs, resulting in significant capital expenditure savings by eliminating the need for specialized HTST and spray drying equipment. Eliminating hydration and spray drying also significantly reduces water and energy consumption, leading to a more sustainable process with a smaller environmental footprint. The absence of HTST treatment minimizes potential color and flavor changes commonly associated with high-temperature reactions, resulting in a higher-quality FSPC with a lighter color and potentially improved flavor. This method can accommodate multiple protein sources, including soy white flakes and SPC powder, providing flexibility and adaptability.

[0059] The invention enables fine-tuning of the FSPC’s functional properties by adjusting several process parameters. The concentration of the alcohol, alkali hydroxide, and reducing agent in the treatment solution can be optimized to control the degree of functionalization. Factors such as temperature, treatment time, and the number of treatment cycles can further influence extractionefficiency and the degree of functionalization. While spray drying is eliminated, a post-extraction drying step is still required to achieve the target moisture content. Vacuum drying within specific temperature and pressure ranges can be used to preserve the product’s functional properties.

[0060] This novel FSPC production method provides an effective and advantageous alternative to conventional methods. By integrating functionalization into the extraction process, the invention offers a simplified, sustainable, and cost-effective method for producing high-quality FSPC with enhanced functional properties for a wide range of food applications.

[0061] Unlike conventional methods that use ethanol-only solutions, the present invention utilizes an alcohol solution with specific additives. The addition of an alkali hydroxide to the alcohol solution adjusts the pH of the treatment medium, affecting protein solubility and initiating structural modifications that enhance functionality.

[0062] The reducing agent further contributes to functionalization. Reducing agents can promote inter-protein bonding, influencing texture and gelling properties, control color development during processing, and may also provide antimicrobial properties, contributing to product stability.

[0063] This modified alcohol solution is the key driver of functionalization, enabling simultaneous extraction and functional modification of the protein source, regardless of its identity (e.g., soy protein derived from soy white flakes or SPC powder).

[0064] The present invention offers flexibility in the use of various plant-based protein sources, including raw materials and processed concentrates. This adaptability allows the functionalization process to be tailored to different protein types and desired end-product characteristics. “Plant-based” refers to materials derived entirely from plants, including but not limited to oilseeds, seeds, legumes, grains, algae, and their processed fractions such as flours, concentrates, meals, and isolates.

[0065] The protein source may be selected from the group consisting of soybean, pea, chickpea, lentil, sunflower, canola, wheat, rice, algae, and combinations thereof. The protein source may be in the form of ftakes, protein concentrate powder, protein isolate powder, meals, flours, and the like. Preferably, the protein source is soy-based, such as soy full-fat flakes, soy white flakes, SPC powder, or a combination thereof. More preferably, the soy protein source comprises soy white flakes, SPC powder, or a combination thereof. “Full-fat flake” refers to a minimally processed soybean product where the hulls have been removed, but the soybean oil remains largely intact. “White flakes” refers to a processed soybean product from which the majority of the oil and hull have been removed, resulting in flakes with a pale, off-white color and a high protein content. This typically involves cracking, dehulling, and solvent extraction of the oil.

[0066] The alcohol utilized in the alcohol solution is not particularly limited, provided it can extract protein from the protein source. Suitable alcohols include, but are not limited to monohydric alcohols, polyhydric alcohols, cyclic alcohols, aromatic alcohols, or a combination of any thereof. Examples include methanol, ethanol, n-propanol, isopropanol, n-butanol, sec-butanol, isobutanol, tert-butanol, pentanol isomers (e.g., amyl alcohol), hexanol isomers, heptanol isomers, octanol isomers, nonanol isomers, decanol isomers, ethylene glycol, propylene glycol, glycerol, butanediol isomers, pentanediol isomers, cyclohexanol, methylcylcohexanol, benzyl alcohol, or a combination thereof. Preferably, the alcohol comprises ethanol.

[0067] The concentration of the alcohol in the alcohol solution may range from about 50% to about 99.95% by volume. Preferably, the concentration ranges from about 65% to about 90% by volume, more preferably from about 65% to about 85% by volume, and even more preferably from about 70% to about 80% by volume, based on the total volume of the alcohol solution.

[0068] In one aspect, the alcohol solution comprises ethanol at a concentration of from about 50% to about 99.95% by volume based on the total volume of the alcohol solution. In a preferred aspect, the alcohol solution comprises ethanol at a concentration of from about 65% to about 90% by volume based on the total volume of the alcohol solution. In a more preferred aspect, the alcohol solution comprises ethanol at a concentration of from about 65% to about 85% by volume based on the total volume of the alcohol solution. In yet a further preferred, the alcohol solution comprises ethanol at a concentration of from about 70% to about 80% by volume based on the total volume of the alcohol solution.

[0069] Suitable alkali hydroxides include, but are not limited to, sodium hydroxide (NaOH), potassium hydroxide (KOH), lithium hydroxide (LiOH), rubidium hydroxide (RbOH), cesium hydroxide (CsOH), or a combination thereof. Preferably, the alkali hydroxide comprises sodium hydroxide and / or potassium hydroxide. More preferably, the alkali hydroxide comprises sodium hydroxide. The alkali hydroxide is present in the alcohol solution at a concentration of from about 0.01 wt% to about 1 wt%, preferably, from about 0.05 wt% to about 0.5 wt%, and more preferably, from about 0.05 wt% to about 0.3 wt%, based on the total weight of the alcohol solution.

[0070] In one aspect, the alcohol solution comprises sodium hydroxide and / or potassium hydroxide at a concentration of from about 0.01 wt% to about 1 wt% based on the totalweight of the alcohol solution. In a preferred aspect, the alcohol solution comprises sodium hydroxide and / or potassium hydroxide at a concentration of from about 0.05 wt% to about 0.5 wt% based on the total weight of the alcohol solution. In a more preferred aspect, the alcohol solution comprises sodium hydroxide and / or potassium hydroxide at a concentration of from about 0.05 wt% to about 0.3 wt% based on the total weight of the alcohol solution.

[0071] Suitable reducing agents include, but are not limited to, sodium metabisulfite (Na2SO5), sodium sulfite (Na2SO3), potassium metabisulfite (K2SO5), calcium sulfite (CaSO3), ascorbic acid, cysteine or a salt thereof, or any combination thereof. In one aspect, the reducing agent comprises a sulfite salt, preferably sodium sulfite and / or sodium metabisulfite, and more preferably sodium metabisulfite.

[0072] The sodium metabisulfite concentration in the alcohol solution may range from about0.01 wt% to about 0.5 wt%, preferably from about 0.02 wt% to about 0.2 wt%, based on the total weight of the alcohol solution. Those skilled in the art will understand that the appropriate concentration of the reducing agent may ultimately depend on its specific identity, as some reducing agents are stronger than others. However, those skilled in the art will be able to deduce the appropriate concentration of other reducing agents based on the disclosure of the concentration of sodium metabisulfite herein.

[0073] Thus, in one aspect, the alcohol solution comprises sodium metabisulfite at a concentration of from about 0.01 wt% to about 0.5 wt% based on the total weight of the alcohol solution. In a preferred aspect, the alcohol solution comprises sodium metabisulfite at a concentration of from about 0.02 wt% to about 0.2 wt% based on the total weight of the alcohol solution.

[0074] In one aspect, the alcohol solution comprises ethanol at a concentration of from about 50% to about 99.95% by volume based on the total volume of the alcohol solution, sodium hydroxide and / or potassium hydroxide at a concentration of from about 0.01 wt% to about 1 wt% based on the total weight of the alcohol solution, and sodium metabisulfite at a concentration of from about 0.01 wt% to about 0.5 wt% based on the total weight of the alcohol solution.

[0075] In a preferred aspect, the alcohol solution comprises ethanol at a concentration of from about 65% to about 90% by volume based on the total volume of the alcohol solution, sodium hydroxide and / or potassium hydroxide at a concentration of from about 0.05 wt% to about 0.5 wt% based on the total weight of the alcohol solution, and sodium metabisulfite at a concentration of from about 0.02 wt% to about 0.2 wt% based on the total weight of the alcohol solution.

[0076] In a more preferred aspect, the alcohol solution comprises ethanol at a concentration of from about 65% to about 85% by volume based on the total volume of the alcohol solution, sodium hydroxide and / or potassium hydroxide at a concentration of from about 0.05 wt% to about 0.3 wt% based on the total weight of the alcohol solution, and sodium metabisulfite at a concentration of from about 0.02 wt% to about 0.2 wt% based on the total weight of the alcohol solution.

[0077] The treatment process generally involves contacting the protein source with the alcohol solution under controlled conditions to facilitate protein extraction and functionalization. The treatment temperature affects the rate of protein treatment and the extent of functionalization. Higher temperatures may accelerate extraction, but excessive temperatures can denature the protein and negatively impact functionality. Preferably, the treatment temperature ranges from about 50 °C to about 90 °C, more preferably, from about 65 °C to about 85 °C, and even more preferably from about 70 °C to about 80 °C.

[0078] The treatment time, in conjunction with temperature, affects the degree of functionalization. Shorter treatment times may suffice at higher temperatures, while lower temperatures may require longer treatments. The treatment time typically ranges from about 30 minutes to about 6 hours, preferably from about 1 hour to about 3 hours, and more preferably, from about 1 .5 hours to about 2.5 hours.

[0079] Multiple treatment stages (washes) with fresh alcohol solution can enhance process efficiency. Each wash extracts additional protein and allows for greater control over product composition and functionality. While a single wash can be effective, preferably, the process comprises at least two washes, more preferably from about 3 to 7 washes, and even more preferably about 7 washes.

[0080] The solvent-to-solid ratio (alcohol solution to protein source) affects extraction efficiency and final protein concentration. A higher ratio favors greater extraction but requires more solvent. The solvent-to-solid ratio can range from about 2:1 to about 40:1 . In a preferred aspect, the solvent-to-solid ratio ranges from about 3:1 to about 20:1 , more preferably, from about 5:1 to about 15:1 , and even more preferably, from about 10:1 to about 15:1 .

[0081] Agitation during treatment ensures uniform contact between the protein source and the alcohol solution, promoting efficient extraction and consistent modification. Suitable agitation methods include stirring, shaking, or rotating the treatment vessel.

[0082] After treatment, the functionalized protein solution is dried to remove the alcohol solvent and obtain a shelf-stable powder. The present invention reduces the number of drying steps compared to conventional methods and offers alternative drying techniques that reduce energy consumption while preserving the protein functionality.

[0083] Vacuum drying is a preferred method, gently removing the solvent at lower temperatures and minimizing protein damage. The extracted protein solution is placed under reduced pressure, typically in a range of from about 2 kPa (20 mbar) to about 60 kPa (600 mbar), more preferably, from about 20 kPa (200 mbar) to about 50 kPa (500 mbar) is employed, and gently heated. The vacuum drying temperature is typically kept below 100 °C to prevent denaturation, preferablyranging from about 20 °C to about 90 °C, more preferably, from about 40 °C to about 90 °C, and even more preferably, from about 60 °C to about 90 °C. Drying time depends on the temperature, vacuum level, and target moisture content and can range from about 5 minutes to about 2 hours, preferably from about 10 minutes to about one hour.

[0084] Other drying methods, such as tray drying or fluid bed drying, may be used under controlled conditions. Careful optimization of drying parameters, including temperature, duration, and airflow, is essential to prevent protein denaturation and preserve functionality.

[0085] In one aspect, drying is performed at about 20 °C to about 90 °C and a pressure of from about 2 kPa (20 mbar) to about 60 kPa (600 mbar), preferably, at about 40 °C to about 90 °C and a pressure of from about 20 kPa (200 mbar) to about 50 kPa (500 mbar), and more preferably, at about 60 °C to about 90 °C and a pressure of from about 20 kPa (200 mbar) to about 50 kPa (500 mbar).

[0086] The final moisture content of the functional protein powder is an important quality attribute. Preferably, the moisture content is below about 10%, more preferably below about 5%, to ensure product stability, prevent spoilage, and maintain functionality.

[0087] After drying, the solid functionalized protein is typically ground to achieve the desired particle size distribution and flow properties for uniform dispersion and functionality in food applications.

[0088] Grinding can be performed using various equipment, including but not limited to, hammer mills, pin mills, jet mills, and roller mills. The grinding method and parameters (such as screen size, rotor speed, and feed rate) will depend on the target particle size distribution, protein fragility, and other process considerations.

[0089] The target particle size depends on the intended application. Finer particles are generally preferred for applications requiring smooth texture and rapid hydration (such as in beverages and sauces), while coarser particles may be suitable for applications where texture is less critical (such as meat analogs or bakery products). The desired particle size may range from about 50 micrometers to about 850 micrometers.

[0090] The present invention achieves enhanced protein functionality during the alcohol extraction step, eliminating the need for a subsequent HTST treatment and spray drying. Therefore, the disclosed methods disclosed do not require an HTST step or a spray drying step after the treatment step.

[0091] Functional Protein

[0092] The present invention also includes the functional protein (e.g., functional soy protein) produced by the disclosed methods. This functional protein exhibits enhanced properties compared to conventionally processed proteins, making it a versatile ingredient for various foodapplications. These enhancements result from the alkali hydroxide and reducing agent treatment during alcohol extraction, modifying protein structure and functionality without requiring subsequent high-temperature processing.

[0093] The functional protein exhibits a modified protein dispersibility index (PDI). In various aspects, the PDI is at least about 10, preferably, at least about 15, and more preferably, at least about 17.5. In another aspect, the functional protein exhibits a PDI ranging from about 10 to about 80, preferably, from about 15 to about 75, more preferably, from about 15 to about 65, and even more preferably, from about 17.5 to about 65. This altered PDI contributes to its enhanced functional properties, such as improved solubility, gelling, and emulsification.

[0094] The protein content of the functional protein is typically about 25% (dry basis) or greater, preferably, about 30% (dry basis) or greater, and more preferably, about 35% (dry basis) or greater. In various aspects, the protein content ranges from about 25% to about 95% (dry basis), preferably, from about 30% to about 90% (dry basis), more preferably, from about 30% to about 85% (dry basis), and even more preferably, from about 35% to about 80% (dry basis).

[0095] The pH of the miscella (treatment medium) after the first wash is typically at least about 6.5, preferably at least about 8.5, more preferably, at least about 9.5, and even more preferably, at least about 10.0. In various embodiments, the miscella pH after the first wash ranges from about 6.5 to about 10.0, preferably, from about 7.5 to about 9.5, and more preferably, from about 7.5 to about 8.5.

[0096] The functional protein exhibits increased peak viscosity compared to proteins produced without alkali hydroxide treatment during alcohol extraction, as measured by RVA. This higherviscosity contributes to improved thickening and texture enhancement in food applications.

[0097] The functional protein also exhibits superior gelling properties. The gel firmness, a measure of the gel’s strength and cohesiveness, is typically at least about 100 g, preferably, at least about 1000 g, and more preferably at least about 1100 g, making it suitable for applications where texture and structure are crucial.

[0098] The functional protein demonstrates enhanced emulsification properties, with an emulsion strength, a measure of its ability to resist separation, of at least about 50 g, preferably at least about 75 g, more preferably at least about 100 g, and even more preferably at least about 125 g, indicating its capacity to stabilize oil-in-water emulsions. This, in turn, helps prevent separation and maintain a desirable mouthfeel in various food applications.

[0099] In addition to functional benefits, the protein often exhibits a lighter color than conventionally processed proteins, which can undergo browning during HTST treatment. Thefunctional protein also retains its nutritional value, as the gentle processing conditions minimize protein denaturation and essential amino acid loss.

[0100] Application in Food Products

[0101] The functional protein produced by the disclosed process is suitable for a wide range of food applications due to its enhanced solubility, gelling, emulsification, and nutritional properties. Its neutral flavor and light color minimize off-notes and undesirable browning often associated with conventional plant-based proteins, allowing for its incorporation into diverse food products without compromising taste or appearance. The functional protein is particularly well-suited for meat alternatives, such as plant-based burgers, sausages, ground ‘meat’ products, seafood analogs, and the like, due to its binding capabilities, texture-enhancing properties, and neutral flavor.

[0102] The protein is also suitable for dairy alternatives, such as plant-based milk, yogurt, cheese, sour cream, cream cheese, whipped cream, and the like. In bakery applications, it can improve the texture, nutritional profile, and shelf life of bread, cakes, fillings, frostings, and the like. It can also be used in gluten-free formulations, where its unique properties can compensate for the absence of gluten. Other applications include protein bars, shakes, powdered beverage mixes, salad dressings, sauces, spreads, and the like.

[0103] The functional protein can be included at from about 0.5 wt% to about 25 wt% of the final product formulation, depending on the desired texture, protein content, and specific application.EMBODIMENTS

[0104] The present invention is further defined in the following embodiments.

[0105] Embodiment 1 is a method for producing functional soy protein powder, the method comprising: (a) treating a soy protein source comprising soy white flakes or soy protein concentrate powder with an alcohol solution comprising alcohol, an alkali hydroxide, and a reducing agent to obtain a functionalized protein fraction; (b) drying the functionalized protein fraction to obtain a dried functionalized protein; (c) grinding the dried functionalized protein to obtain a functional soy protein powder.

[0106] Embodiment 2 is the method of embodiment 1 , wherein the alcohol solution comprises from about 50% to about 99.95% alcohol by volume based on the total volume of the alcohol solution.

[0107] Embodiment 3 is the method of embodiments 1 or 2, wherein the treating step comprises washing the protein source with the alcohol solution at least two times.

[0108] Embodiment 4 is the method of any one of embodiments 1 to 3 wherein the reducing agent comprises a sulfite salt.

[0109] Embodiment 5 is the method of embodiment 4, wherein the sulfite salt is sodium metabisulfite.

[0110] Embodiment 6 is the method of embodiment 4 or 5, wherein the sulfite salt is present in the alcohol solution at a concentration of about 0.01 wt% to about 0.5 wt% based on the total weight of the alcohol solution.

[0111] Embodiment 7 is the method of any one of embodiments 1 to 6, wherein the alkali hydroxide is selected from the group consisting of sodium hydroxide, potassium hydroxide, and mixtures thereof.

[0112] Embodiment 8 is the method of any one of embodiments 1 to 7, wherein the alkali hydroxide is present in the alcohol solution at a concentration of about 0.01 wt% to about 1 wt% based on the total weight of the alcohol solution,

[0113] Embodiment 9 is the method of any one of embodiments 1 to 8, wherein the treating step is performed at a temperature of from about 50 °C to about 90 °C for about 1 hour to about 3 hours.

[0114] Embodiment 10 is the method of any one of embodiments 1 to 9, wherein the drying step is performed using vacuum drying.

[0115] Embodiment 11 is the method of embodiment 10, wherein the vacuum drying step is performed at a temperature of from about 20 °C to about 100 °C and a pressure of about 2 kPa (20 mbar) to about 50 kPa (500 mbar) for from about 10 minutes to about 1 hour.

[0116] Embodiment 12 is the method of any one of embodiments 1 to 11 , wherein the method does not comprise a high-temperature short-time (HTST) step and / or a spray drying step after the treating step.

[0117] Embodiment 13 is the functional soy protein produced by the method of any one of claims 1 to 12.

[0118] Embodiment 14 is the functional soy protein of embodiment 13, wherein the protein has one or more of the following characteristics: a PDI of about 10 or greater; a protein content of about 25% or greater, on a dry basis; a miscella pH of about 6.5 or greater after a first wash with the alcohol solution, preferably at least about 8.5; an increased peak viscosity measured by rapid visco analysis (RVA) as compared to a soy protein concentrate produced by a method that does not utilize an alcohol solution comprising an alkali hydroxide for treatment; a gel firmness of about 100 g or greater; an emulsion strength of 50 g or greater.

[0119] Embodiment 15 is a method for improving at least one functional property of soy protein, the method comprising: (a) adding an alkali hydroxide and a sulfite salt to an aqueous alcohol solution comprising from about 50% to about 99.95% alcohol by volume based on the total volumeof the aqueous alcohol solution; (b) treating soy white flakes or soy protein concentrate powder with the aqueous alcohol solution of step (a); and (c) drying the treated protein solution to obtain a functional soy protein concentrate, wherein the at least one functional property is selected from the group consisting of increased viscosity, enhanced gelling characteristics, and improved emulsification properties, compared to untreated soy white flakes or soy protein concentrate powder.EXAMPLES

[0120] The following examples are illustrative and do not limit the scope of the invention. Unless otherwise indicated, all percentages, parts, and ratios are by weight.

[0121] Example 1 : White Flake Extraction in NaOH and Ethanol

[0122] This Example demonstrates the effect of NaOH concentration on SPC characteristics during ethanolic extraction. Hexane-extracted soy white flakes (Bunge) with a PDI of 4.7, 5.6% moisture content, 0.78% residual oil content, and 53.89% protein content (dry basis) were used. Three ethanolic solutions (70 vol% ethanol, 30 vol% water) containing 0%, 0.15%, and 1 % w / v NaOH were prepared.

[0123] In a jacketed reactor (FIG. 1), 500 g of white flakes were heated to 85 °C and washed seven times with each ethanol solution. A 4:1 solvent-to-solid ratio was used for each wash, with a 12-minute extraction and a 5-minute draining time to simulate industrial-scale extraction. After the final wash, the ethanol was drained, and the extracted white flakes were dried using a rotary evaporator (85 °C, 25 mbar), followed by oven drying at 85 °C overnight,

[0124] The results are summarized in Tables 1-3 and FIGS. 2 and 3.

[0125] Table 1. SPC Characteristics (Dry Basis)

[0126] Table 2. Miscella pH

[0127] Table 3. Molasses Characteristics (As Is)

[0128] NaOH treatment significantly affected SPC properties, as shown by the changes in protein content, PDI, and RVA profiles (Table 1 and FIG. 2). High NaOH concentrations (1 %) appeared to partially solubilize or react with the white flakes, affecting product characteristics (Table 1 ). The increasing miscella pH suggests a possible reaction between NaOH and ethanol. Color variations (FIG. 3) further support chemical changes during high-concentration NaOH extraction.

[0129] This Example demonstrates the potential for modifying functionality using NaOH during ethanolic extraction.

[0130] Example 2: Functional Properties of SPC Extracted with NaOH and Ethanol

[0131] This Example further investigates the functional properties of SPC extracted with varying NaOH concentrations. Hexane-extracted white flakes (Bunge; PDI 4.7, 5.6% moisture, 0.78% residual oil, and 53.89% protein (dry basis)) were used. Three treatment solutions (70 vol% ethanol, 30 vol% water) with 0%, 0.05%, and 0.10% w / v NaOH were prepared. The extraction procedure was identical to Example 1 : 500 g of white flakes were washed seven times with each solution (4:1 solvent-to-solid ratio, 12-minute extraction, 5-minute draining) in a jacketed reactor at 85 °C. After ethanol removal, samples were dried using a rotary evaporator (85 °C, 25 mbar) and then in an oven (85 °C) overnight.

[0132] SPC samples were analyzed for viscosity using RVA at 12.5% concentration (FIG. 4). Increasing NaOH concentrations resulted in higher viscosities, indicating protein functionalization. Commercially available products showed a different viscosity profile (FIG. 5), but the NaOH-treated samples exhibited a similar trend of increased final viscosity with increasing NaOH, also suggesting functionalization.

[0133] Gel strength and emulsion capacity of the samples were also evaluated (FIGS. 6A and 6B; at 1 :4.4 and 1 :4 concentration, respectively, and cooked to an internal temperature of 165 °F using a stepped method).

[0134] Gel strength was measured by compression of the samples using a Texture Analyzer (TXT2 plus “Stable Micro Systems”) with a 5 kN load cell and Texture Expert Exceed 2.52 software (Stable Micro Systems, Surrey, England). A 25 mm compression test was performed using a 1 -inchcylindrical probe at 10 mm / s. Gel strength was defined as the maximum force (in grams) required to compress the sample.

[0135] The 0.05% and 0.1 % NaOH treatments achieved gel firmness comparable to ARCON SM (ADM), a commercial functional protein benchmark. Their emulsion strength exceeded that of 70N-50 (Bunge), indicating the potential for superior emulsification.

[0136] These results demonstrate that adjusting NaOH concentration during extraction phase allows for fine-tuning of SPC functional properties.

[0137] Example 3: White Flake Extraction with KOH and Ethanol

[0138] This Example investigates the effect of KOH concentration on SPC characteristics during ethanolic extraction. Hexane-extracted white flakes (Bunge) with a PDI of 4.7, 5.6% moisture content, 0.78% residual oil content, and 53.89% protein content (dry basis) were used. Two ethanolic solutions (70 vol% ethanol, 30 vol% water) containing 0.05% and 0.1 % w / v KOH were prepared.

[0139] The extraction procedure was the same as in Examples 1 and 2: 500 g of white flakes were washed seven times with each KOH solution (4:1 solvent-to-solid ratio, 12-minute extraction, 5-minute draining) in a jacketed reactor at 85 °C. After ethanol removal, samples were dried using a rotary evaporator (85 °C, 25 mbar) and then in an oven (85 °C) overnight.

[0140] The resulting SPC samples were analyzed for viscosity using RVA at 12.5% concentration (FIGS. 7 and 8). Increasing KOH concentration led to higher viscosities, suggesting protein functionalization. Commercially available products exhibited a different viscosity profile with a higher initial viscosity (FIG. 8), but the KOH-treated samples showed a similar trend of increased final viscosity with increasing KOH, also suggesting functionalization.

[0141] KOH treatment also modified the gelling temperature of the SPC, potentially enabling lower-temperature (e.g., room temperature) gelling and a higher initial viscosity.

[0142] Example 4: White Flakes vs. SPC on NaOH Treatment Effectiveness

[0143] This Example investigates the influence of the starting material, specifically comparing soy protein concentrate (SPC) and white flakes, on the functional properties of the final product when treated with 0.1 % NaOH in a 70% ethanolic solution. Hexane-extracted white flakes (sourced from Bunge) with a PDI of 4.7, 5.6% moisture content, 0.78% residual oil content, and 53.89% protein content (dry basis) were used.

[0144] For the white flake treatment, 500 g were placed in a jacketed reactor and heated to85 °C. The material was subjected to seven washes with a 4:1 solvent-to-solid ratio of the NaOH solution. Each wash involved a 12-minute extraction followed by a 5-minute draining period tosimulate industrial-scale extraction processes. Following the final wash, the ethanol was drained, and the extracted flakes were dried using a rotary evaporator (85 °C, 25 mbar) and further dried in an oven at 85 °C overnight.

[0145] Separately, ethanol washed SPC (70.3% protein (dry basis), 5.90% moisture content, 0.65% residual oil content) was also obtained (sourced from Bunge). For SPC treatment, 500 g was added to the jacketed reactor and heated to 85 °C. The material was soaked once in a 4:1 solvent-to-solid ratio of the NaOH solution for one hour, followed by ethanol removal. The treated SPC was then dried in an 85 °C oven overnight.

[0146] The samples from both starting materials were evaluated for their viscosity using Rapid Visco Analysis (RVA) at a 12.5% concentration (FIGS. 9 and 10). Commercial products were included for comparison. While the commercial products exhibited higher initial viscosity, the final viscosities of the treated samples showed a significant increase compared to standard SPC and reached similar levels to the final viscosity of the commercial products. However, using white flakes as the starting material, under the described processing conditions, appeared to slightly reduce the effectiveness of the gelling characteristics, as demonstrated by the smaller peak in the RVA curve.

[0147] Example 5: Influence of Sodium Metabisulfite Concentration on Functional Properties of NaOH-Treated White Flakes

[0148] This Example examines the impact of incorporating sodium metabisulfite (NaMTBS) during the NaOH treatment of white flakes on the functional properties of the resulting SPC. Hexane- extracted white flakes (sourced from Bunge) with a PDI of 4.7, 5.6% moisture content, 0.78% residual oil content, and 53.89% protein content (dry basis) were used.

[0149] In a jacketed reactor, 500 g of white flakes were heated to 85 °C and treated with solutions containing 0.1 % NaOH and varying concentrations of NaMTBS (0.05% and 0.1%) in a 70% ethanolic solution. The material underwent seven washes, each with a 4:1 solvent-to-solid ratio, a 12-minute extraction period, and a 5-minute draining period. After the final wash, the ethanol was drained, and the extracted flakes were dried using a rotary evaporator (85 °C, 25 mbar), followed by oven drying at 85 °C overnight.

[0150] The treated samples were evaluated for their viscosity using Rapid Visco Analysis (RVA) at a 12.5% concentration (FIGS. 11 and 12). The addition of NaMTBS notably increased the initial viscosity of the samples, aligning them more closely with the profiles of commercially available products (FIG. 12). Interestingly, a 0.05% NaMTBS addition yielded a more significant viscosity increase compared to the 0.1 % addition, indicating a potential optimal NaMTBS concentration for maximizing this functional property.

[0151] Beyond viscosity, the emulsion stability of the samples was also assessed (at 1 :4.4 concentration and cooked until 165 °F internally in a stepped method). Emulsion strength analysis (FIG. 13) revealed that the samples were comparable to the commercial reference (ACRON SM), with the 0.05% NaMTBS treatment achieving the most favorable emulsion strength, reaching approximately 50% of the firmness observed in current Bunge offerings.

[0152] Example 6: Optimization of Final Washing Procedures on Functional Properties ofNaOH and NaMTBS-Treated White Flakes

[0153] This Example investigates the impact of different final washing procedures on the functional properties of white flakes treated with NaOH and NaMTBS. Hexane-extracted white flakes (sourced from Bunge) with a PDI of 4.7, 5.6% moisture content, 0.78% residual oil content, and 53.89% protein content (dry basis) were used.

[0154] In a jacketed reactor, 500 g of white flakes were heated to 85 °C. The material underwent six initial washes with a 4:1 solvent-to-solid ratio of a solution containing 0.1 % NaOH and 0.1 % NaMTBS in 70% ethanol. Each wash consisted of a 12-minute extraction and a 5-minute draining period. After the sixth wash, a final "washing procedure" was implemented to eliminate residual reagents and improve the color and flavor of the final product. This involved washing with either the standard solution (0.1 % NaOH, 0.1 % NaMTBS) as a control or with 99.7%, 88.0%, or 70% pure ethanol.

[0155] Following the final wash, the ethanol was drained, and the extracted flakes were dried using a rotary evaporator (85 °C, 25 mbar) and subsequently in an 85 °C oven overnight.

[0156] The treated samples were evaluated for their viscosity using Rapid Visco Analysis (RVA) at a 12.5% concentration (FIG. 14 and FIG. 15). Washing with 99.7% and 70% pure ethanol produced results similarto the standard procedure. However, the 88% ethanol wash slightly reduced the initial viscosity without significantly impacting the final viscosity. While these products exhibited functional properties, they appeared slightly less firm than the commercial reference products.

[0157] Emulsion stability was also assessed (at a 1 :4.4 concentration and cooked until 165 °F internally in a stepped method). Interestingly, the concentration of ethanol in the final wash had a non-linear effect on emulsion strength, suggesting an optimal concentration for maximizing this property (FIG. 16). Washing with 99.7% and 70% ethanol yielded emulsions with higher strength and salt resistance compared to the standard procedure.

[0158] Example 7: Impact of NaOH and NaMBS Concentrations and Ethanol Washing onSPC Functional Properties

[0159] This example examines the effects of NaOH and NaMBS concentrations, and ethanol washing procedures, on SPC functional properties.

[0160] Hexane-extracted white flakes (Bunge; PDI 67.14, 6.51 % moisture, 0.78% residual oil, 53.89% protein (dry basis)) were used. 500 g of flakes were treated in a jacketed reactor at 85°C with a 1 :4 solvent-to-solid ratio.

[0161] The material was washed seven times with either 60% or 70% ethanol, with ethanol removal after each wash. After the final wash, the ethanol was drained, and the extracted flakes were dried using a rotary evaporator (25 mbar, 85°C) and then in an oven (85°C) overnight.

[0162] SPC samples were analyzed using RVA at a 12.5% concentration. FIG. 17 shows the RVA curves at 75°C for SPC treated with 0.1 % NaOH and 0.1 % NaMBS and washed with either 60% or 70% ethanol, compared to commercial standards (ACRON SM and 70N-50). FIG. 18 shows the comparative RVA curves at 130°C.

[0163] In FIG. 17, both ethanol-washed SPC samples exhibited higher peak viscosities and more stable viscosity profiles than the commercial samples. The 70% ethanol-washed SPC showed a sharper initial viscosity increase and a higher overall viscosity than the 60% ethanol-washed sample at 75°C. In FIG. 18, both ethanol-washed SPC samples maintained higher viscosity profiles at 130°C than ACRON SM and 70N-50. The 70% ethanol-washed SPC had a slightly higher initial viscosity peak and a more gradual decrease overtime, suggesting better viscosity stability at elevated temperatures.

[0164] These results demonstrate that adjusting the ethanol concentration in the final wash allows for fine-tuning of SPC viscosity. Both 60% and 70% ethanol washes produced SPC with better viscosity characteristics than the commercial references, suggesting enhanced gelling and thickening properties.

[0165] Example 8: 0.1 % NaOH in 70% Ethanol Solution: Bench and Pilot Scale

[0166] This example demonstrates the scalability of SPC extraction and functionalization using 0.1 % NaOH in 70% ethanol, comparing bench-scale and pilot-scale reactors.

[0167] Hexane-extracted white flakes (Bunge; PDI 67.14, 5.6% moisture, 0.78% residual oil, 53.89% protein (dry basis)) were sifted through a #12 sieve, and the passing particles were collected.

[0168] Bench Scale Process: 500 g of white flakes were processed in a jacketed reactor at 85°C. The material was washed seven times (4:1 solvent-to-solid ratio, 12-minute extraction, 5- minute draining) with ethanol removal after each wash. Drying was performed using a rotary evaporator (25 mbar, 85°C) and then in an oven (85°C) overnight.

[0169] Pilot-Scale Process: 4 kg of white flakes were processed in a continuous pilot-scale Crown Iron Model IV System (Blaine, MN) with four extraction stages. The feed rate was 10 g / min, and the 70% ethanol flow rate was approximately 130 mL / min (13:1 solvent-to-flake ratio). NaOH was added at 13 g / kg of white flakes. The operating temperature was 65°C.

[0170] The pilot system's VFD was set to 17.5 Hz (90-minute residence time). The material was washed twice with 99% ethanol (15-minute wash, 5-minute draining) with ethanol removal after each wash. Dryingwas performed as in the bench-scale process.

[0171] Functional Property Analysis: SPC samples were analyzed using RVA at a 12.5% concentration. FIG. 19 shows the RVA curves at 75°C, and FIG. 20 shows the RVA curves at 130°C, comparing bench and pilot-scale samples to commercial standards (ARCON SM and 70N-50).

[0172] In FIG. 19, both bench and pilot samples showed higher initial viscosities than the commercial standards. The bench-scale sample had a sharper peak viscosity.

[0173] In FIG. 20, both bench and pilot samples maintained higherviscosity profiles than the commercial samples. The bench sample had a higher initial peak, but the pilot sample maintained stable viscosity throughout.

[0174] Protein and PPI Analysis: Protein and PDI results are shown in FIG. 21. Both bench and pilot samples had comparable protein content to commercial samples, with slightly lower PDI values than ARCON SM.

[0175] Emulsion Strength Analysis: Emulsion strength (1 :4.4 concentration, cooked to 165°F internally) is shown in FIG. 22. Bench and pilot samples had higher emulsion strength than commercial samples.

[0176] These results demonstrate successful scale-up from bench to pilot scale, maintaining enhanced functional properties (viscosity, emulsion strength, protein stability) compared to commercial standards.

[0177] Example 9: Effect of Particle Size on Bench-Scale Extraction

[0178] This example investigates the impact of particle size distribution (natural vs. #12 sieve) on SPC functional properties in a bench-scale reactor.

[0179] Hexane-extracted white flakes (Bunge; PDI 67.14, 5.6% moisture, 0.78% residual oil, 53.89% protein (dry basis)) were used.

[0180] Average particle size was determined using the ROTAP method. 200 g of material was sifted through a stack of 8” sieves (#5 / 16, #1 / 4, #6, #7, #10, #12, #16, #20, and pan). Table 4 shows the particle size distribution.

[0181] Table 4. White Flakes Sifting Results

[0182] The #12 sieve fraction was selected for further experimentation.

[0183] SPC Production and Analysis: Two 500 g groups of white flakes (natural and #12- sieved) were processed in a jacketed reactor at 85°C.

[0184] Both groups were washed seven times (4:1 solvent-to-solid ratio, 12-minute extraction, 5-minute draining) with ethanol removal after each wash. Drying was performed as in previous examples.

[0185] SPC samples (12.5% concentration) were analyzed using RVA. FIG. 23 shows the RVA curves at 75°C, and FIG. 24 shows the RVA curves at 130°C, comparing natural and sieved samples to commercial standards (ARCON SM and 70N-50).

[0186] In FIG. 23, the #12-sieved sample showed significantly higher peak viscosity than the natural sample at 75°C. Both samples outperformed commercial standards.

[0187] In FIG. 24, the #12-sieved sample maintained a higher viscosity profile at 130°Cthan the natural sample and both commercial standards.

[0188] These results demonstrate that sieving enhances SPC functional properties, especially viscosity and gelling.

[0189] Example 10: Effect of Extraction Temperature in Pilot-Scale Reactors

[0190] This example investigates the impact of extraction temperature (45°C and 65°C) on SPC functional properties in a pilot-scale reactor using 70% ethanol.

[0191] Hexane-extracted white flakes (Bunge; PDI 67.14, 5.6% moisture, 0.78% residual oil, 53.89% protein (dry basis)) were used.

[0192] Approximately 4 kg of white flakes were processed (10 g / min feed rate, 130 mL / min 70% ethanol flow rate; 13:1 solvent-to-flake ratio). NaOH was added at 13 g / kg of white flakes. The operating temperature was either 45°C or 65°C.

[0193] The pilot plant's VFD was set to 17.5 Hz (90-minute residence time).

[0194] The extracted flakes were washed twice with 99% ethanol (15-minute wash, 5- minute draining) with ethanol removal after each wash. Drying was performed as in previous examples.

[0195] Functional Property Analysis: Protein content and PDI results are shown in FIG. 25. Both temperatures yielded protein levels comparable to commercial standards. The 65°C samples had slightly lower PDI values than ARCON SM.

[0196] Emulsion strength (1 :4.4 concentration, uncooked and cooked to 165°F) is shown in FIG. 26.

[0197] The 65°C treatment produced the highest emulsion strength after cooking, exceeding both non-functional and commercial standards. The 45°C sample also showed improved emulsion strength after cooking compared to commercial standards. Before cooking, both samples had similar emulsion strength to the market product.

[0198] Both temperatures produced SPC with enhanced functional properties, with 65°C being optimal for emulsion strength after cooking.

[0199] This example demonstrates that the process is robust across different extraction temperatures.

[0200] Example 11 : Effect of Solvent-to-Flake Ratio in Pilot-Scale Reactors

[0201] This example investigates the impact of solvent-to-flake ratios (27:1 , 13:1 , 7:1 ) on SPC functional properties in pilot-scale reactors using 70% ethanol.

[0202] Hexane-extracted white flakes (Bunge; PDI 67.14, 5.6% moisture, 0.78% residual oil, 53.89% protein (dry basis)) were used.

[0203] Approximately 4 kg of white flakes were processed (10 g / min feed rate, 270, 130, or 70 mL / min 70% ethanol flow rate for the respective ratios). NaOH was added at 13 g / kg of white flakes. The operating temperature was 65°C.

[0204] The pilot plant's VFD was set to 17.5 Hz (90-minute residence time). Washing and drying were performed as in previous examples.

[0205] Functional Property Analysis: Protein and PDI results are shown in FIG. 27. All samples showed consistent protein levels and slightly lower PDIs than the commercial standard.

[0206] Emulsion strength (1 :4.4 concentration, uncooked and cooked to 165°F) is shown in FIG. 28. The 13:1 ratio yielded the highest emulsion strength after cooking, exceeding both nonfunctional and commercial standards. The other ratios also showed improved emulsion strength after cooking compared to the commercial standards. Before cooking, all samples had slightly lower emulsion strength than the standard product.

[0207] This example demonstrates process flexibility across different solvent-to-flake ratios, maintaining high functional properties

[0208] Example 12: Effect of Retention Time in Pilot-Scale Reactors

[0209] This example investigates the impact of retention times (65, 90, 120 minutes) on SPC functional properties in pilot-scale reactors using 70% ethanol.

[0210] Hexane-extracted white flakes (Bunge; PDI 67.14, 5.6% moisture, 0.78% residual oil, 53.89% protein (dry basis)) were used.

[0211] Approximately 4 kg of white flakes were processed (10 g / min feed rate, 130 mL / min 70% ethanol flow rate; 13:1 solvent-to-flake ratio). NaOH was added at 13 g / kg of white flakes. The operatingtemperature was 65°C. The pilot plant's VFD was set to achieve the desired retention times. Washing and drying were performed as in previous examples.

[0212] Functional Property Analysis: Protein and PDI results are shown in FIG. 29. All samples maintained high protein levels and lower PDI values than the functional market reference.

[0213] Emulsion strength (1 :4.4 concentration, uncooked and cooked to 165°F) is shown in FIG. 30. The 90-minute retention time yielded the highest emulsion strength after cooking. All retention times resulted in higher emulsion strength after cooking than the market standards. Before cooking, emulsion strength was similar to or slightly lower than the functional market standard.

[0214] This example demonstrates process robustness across different retention times, with 90 minutes being optimal for emulsion strength after cooking.

[0215] Example 13: Co-Current vs. Counter-Current Extraction at Pilot-Scale

[0216] This example compares co-current and counter-current extraction methods for producing SPC at pilot scale.

[0217] Hexane-extracted white flakes (Bunge; PDI TIJ1, 6.31 % moisture, 0.65% residual oil, 51 .19% protein (dry basis), 29.81 lb / ft3bulk density) were used.

[0218] Approximately 500 kg of white flakes were processed (75 g / min feed rate, 525 mL / min 70% ethanol flow rate; 5:1 solvent-to-flake ratio). NaOH was added at 13 g / kg of white flakes. The operating temperature was 70°C.

[0219] A two-extractor system (FIG. 31 ) was used (9-minute retention time in the first extractor, 150-minute retention time in the second).

[0220] Counter-Current: NaOH dissolved in ethanol was introduced at inlet 2 (FIG. 31 ).

[0221] Co-Current: NaOH was added to the soaking ethanol (inlet 1 ). FIG. 32 shows the ethanol and NaOH concentration profiles.

[0222] Functional Property Analysis: Table 5 summarizes the results for both extraction methods and commercial standards (ACRON SM and 70N-50).

[0223] Table 5. Co-Current vs. Counter-Current Extraction Analysis

[0224] Both methods produced SPC with comparable protein and moisture levels to market standards. Co-current extraction showed slightly better protein concentration and emulsion strength. Both methods improved emulsion strength after cooking, with co-current extraction yielding the highest value (245.4).

[0225] Color and oil content were consistent across both methods. PDI values were lower than market comparatives.

[0226] This example demonstrates process flexibility and effectiveness across different extraction configurations, with co-current extraction showing slightly better performance.

[0227] Example 14: Comparing DDD and VPS Drying in Co-Current Pilot-Scale Extraction

[0228] This example compares the effects of different drying equipment (DDD and VDS) on SPC functional properties in a pilot-scale co-current extraction process.

[0229] Hexane-extracted white flakes (Bunge; PDI TIJ1, 6.31% moisture, 0.65% residual oil, 51.19% protein (dry basis), 29.81 lb / ft3bulk density) were used.

[0230] The process conditions (500 kg white flakes, 75 g / min feed rate, 525 mL / min 70% ethanol flow rate, 5:1 solvent-to-flake ratio, 13 g / kg NaOH, 70°C operating temperature) and the two- extractor system (FIG. 31 ) were the same as in Example 13.

[0231] Drying Process: NaOH was added to the soaking ethanol (1 :10 of flow) at position 1 (co-current layout). The NaOH concentration profiles are shown in FIG. 32.

[0232] The extracted SPC was washed with 99% ethanol, pressed to ~50% moisture, and dried using either: (a) DDD (ambient pressure) or (b) VDS (vacuum).

[0233] Table 6 shows the dryer parameters for both systems (target moisture content < 10%, 85°C average temperature, ~35-minute residence time).

[0234] Table 6. Dryer Parameters

[0235] SPC samples were analyzed. Results are summarized in Table 7.

[0236] Table 7. Analytical Results of VDS vs. DDD Drying

[0237] Both drying systems produced SPC with similar protein, moisture, oil, and slightly lower PDI levels. VDS showed slightly higher emulsion strength after cooking. Before cooking, the market product had slightly higher emulsion strength.

[0238] This example demonstrates process robustness across different drying systems, with VDS showing a slight advantage in emulsion strength after cooking.

[0239] As various changes could be made in the above constructions, products, and methods without departing from the scope of the invention, it is intended that all matter contained in the above description and shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

Claims

CLAIMSWhat is claimed is:1 . A method for producing functional soy protein powder, the method comprising:(a) treating a soy protein source comprising soy white flakes or soy protein concentrate powder with an alcohol solution comprising alcohol, an alkali hydroxide, and a reducing agent to obtain a functionalized protein fraction;(b) drying the functionalized protein fraction to obtain a dried functionalized protein;(c) grinding the dried functionalized protein to obtain a functional soy protein powder.

2. The method of claim 1, wherein the alcohol solution comprises from about 50% to about 99.95% alcohol by volume based on the total volume of the alcohol solution.

3. The method of claim 1 or 2, wherein the treating step comprises washing the soy protein source with the alcohol solution at least two times.

4. The method of any one of claims 1 to 3, wherein the reducing agent comprises a sulfite salt.

5. The method of claim 4, wherein the sulfite salt is sodium metabisulfite.

6. The method of claim 4 or 5, wherein the sulfite salt is present in the alcohol solution at a concentration of about 0.01 wt% to about 0.5 wt% based on the totalweight of the alcohol solution.

7. The method of any one of claims 1 to 6, wherein the alkali hydroxide is selected from the group consisting of sodium hydroxide, potassium hydroxide, and mixtures thereof.

8. The method of any one of claims 1 to 7, wherein the alkali hydroxide is present in the alcohol solution at a concentration of about 0.01 wt% to about 1 wt% based on the total weight of the alcohol solution.

9. The method of any one of claims 1 to 8, wherein the treating step is performed at a temperature of from about 50 °C to about 90 °C for about 1 hour to about 3 hours.

10. The method of any one of claims 1 to 9, wherein the drying step is performed using vacuum drying.11 . The method of claim 10, wherein the vacuum drying step is performed at a temperature of from about 20 °C to about 100 °C and a pressure of about 2 kPa (20 mbar) to about 50 kPa (500 mbar) for from about 10 minutes to about 1 hour.

12. The method of any one of claims 1 to 11 , wherein the method does not comprise a high- temperature short-time (HTST) step and / or a spray drying step after the treating step.

13. Functional soy protein produced by the method of any one of claims 1 to 12.

14. The functional soy protein of claim 13, wherein the protein has one or more of the following properties: a PDI of about 10 or greater; a protein content of about 25% or greater, on a dry basis; a miscella pH of about 6.5 or greater after a first wash with the alcohol solution, preferably about 8.5 or greater after a first wash with the alcohol solution; an increased peak viscosity measured by rapid visco analysis (RVA) as compared to a soy protein concentrate produced by a method that does not utilize an alcohol solution comprising an alkali hydroxide for treatment; a gel firmness of about 100 g or greater; an emulsion strength of 50 g or greater.

15. A method for improving at least one functional property of soy protein, the method comprising:(a) adding an alkali hydroxide and a sulfite salt to an aqueous alcohol solution comprising from about 50% to about 99.95% alcohol by volume based on the total volume of the aqueous alcohol solution;(b) treating soy white flakes or soy protein concentrate powderwith the aqueous alcohol solution of step (a); and(c) drying the treated protein solution to obtain a functional soy protein concentrate,wherein the at least one functional property is selected from the group consisting of increased viscosity, enhanced gelling characteristics, and improved emulsification properties, compared to untreated soy white flakes or soy protein concentrate powder.

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