Process for obtaining sunflower protein isolate

Abstract

The present disclosure is directed to a process for obtaining sunflower protein isolate, encompassing the steps of dehulling, cold pre-pressing, oil extraction, protein extraction, and isolate purification. The process optimizes protein yield while employing mild processing conditions to preserve functionality. The obtained isolates exhibit high protein content, desirable emulsifying and water / oil holding capacities, and neutral color profiles, rendering them suitable for use in various food applications. Thus, also disclosed are a sunflower globulin protein isolate, a sunflower albumin protein isolate and a use of the sunflower globulin protein isolate or a sunflower albumin protein isolate in a food product.

Description

[0001] PROCESS FOR OBTAINING SUNFLOWER PROTEIN ISOLATE

[0002] FIELD OF THE INVENTION

[0003]

[0001] The present disclosure is directed to a process for obtaining sunflower protein isolates. In particular, it provides an efficient and cost-effective industrial process to produce sunflower protein isolates. Also disclosed are a sunflower globulin protein isolate, a sunflower albumin protein isolate and the use thereof in a food application.

[0004] BACKGROUND OF THE INVENTION

[0005]

[0002] Sunflower (Helianthus) seed has a great potential for meeting the increasing demand for edible proteins due to its high protein content in the sunflower meal. In terms of world production, sunflower seed is the third largest oilseed produced. Sunflower meal is used primarily in ruminant feed, but its nutritional, sensory and functional properties make sunflower meal potentially useful for human foods as well. Currently there in an increased demand for vegetable proteins as alternatives of animal proteins. However, sunflower seed contains some undesirable components which affect its use as a source of dietary protein.

[0006]

[0003] Sunflower seeds contain a substantial quantity of hulls (about 22 to 30 %) which are partially removed in a conventional sunflower seed crushing process. Commercial partial dehulling results in an 8 to 13 % residual hull content in the dehulled seed. Residual hull content of the dehulled seed is important in the pressing step, as hulls facilitate the de-oiling and the formation of a proper press cake structure. This is important in a conventional industrial percolation type of extraction process. The de-oiling of the seeds by either mechanical pressing or solvent extraction concentrates the residual hull content in the meal. However, this results in a dark, brownish color and unpleasant bitter taste to the meal and thus to the protein isolated from the sunflower meal. Further it has low protein dispersibility values.

[0007]

[0004] In a conventional sunflower seed crushing process, there are several steps performed at high temperature (above 80 °C) for a certain time. The most important heat treatment step is in the toaster, where traces of the solvent are stripped off the meal at high temperature, resulting in protein denaturation. Due to protein denaturation and Maillard reactions, conventional sunflower seed meal has a low protein solubilization yield and a light brown or beige color. Further, it brings a bitter taste to the resulting protein isolate.

[0008]

[0005] Sunflower press cake may also be used as raw material for protein isolation processes, as during the toasting step the proteins do not undergo a denaturation and the sugars do not undergo Maillard reactions. However, the problem using press cake as raw material for protein isolation is that it has a high oil content, up to 18 to 22 %. This high oil content makes aqueous separation steps difficult at an industrial scale. Small amounts of residual oil of the clarified solubilized aqueous protein liquid fraction can easily foul the membrane in the ultrafiltration step.

[0009]

[0006] Sunflower seeds contain polyphenols or phenolic compounds — mostly chlorogenic acid, but also caffeic acid — which is a major drawback to the use of sunflower protein in food products. Due to their chromophore properties and their oxidized forms, the protein functionality and taste is negatively affected. Chlorogenic acid is a colorant compound that oxidizes rapidly under alkaline pH environments. It creates complexes with proteins, having a negative impact on protein functionality as well as a dark color (e.g., dark green or dark brown) formation. If the pH of sunflower flour or meal is raised above its neutral point, the color progresses from a creamy yellow or light green to dark green. As a result of enzymatic oxidation, the color tends to turn into brown. When the proteins are precipitated, at pH 4.5, the green color cannot be removed from the isolated protein.

[0010]

[0007] There are two different approaches to solve the problem of the presence of polyphenols. A first approach is to remove polyphenols from the raw material by solvent washing (with, for example, methanol, ethanol, isopropyl alcohol, butanol, polar solvents). However, due to alcohol washing, proteins tend to denature and cannot be solubilized in the protein extraction step, thereby decreasing the production yield. Membrane filtration or ion exchange with resins is also used to remove polyphenols. A second approach is to avoid oxidation of polyphenols by applying an inert gas blanket or inert gas atmosphere. However, this is a very costly process.

[0008] U.S. Patent No. 3,993,636 describes a protein extraction process from sunflower seed meals at a pH ranging from 8 to 12 and the addition of sodium sulfite (from 0.5 to 0.10 % by weight). The alkaline liquid extract phase is then ultrafiltered at alkaline pH to obtain a protein isolate having nitrogenous matter between about 85% and 95% by weight of the total dry matter. The temperature used during this process is between 20 and 50 °C, preferably about 40 °C. This reference also describes the need to remove colored impurities.

[0011]

[0009] U.S. Patent No. 3,622,556 describes an isolation method of conventional sunflower seed meal by an extraction step at a pH ranging from 9 to 11. During the alkaline extraction step, the sunflower meal and water mixture is covered with an inert gas blanket followed by basic pH adjustment. If this inert gas blanket is not used, an intense green color, which cannot be removed by any ordinary purification method, will appear. The reference also describes membrane ultrafiltration in combination with the inert gas blanket.

[0010] U.S. Patent No. 3,586,662 discloses the preparation of a light-colored protein isolate from sunflower meal by acid washing prior to alkaline extraction. In this manner, an intense green color does not occur, and the isolate can be used as a supplement in food products.

[0012] [Oil] Sunflower seed proteins are composed of two main fractions. The major globulin fraction is an 1 IS globulin called Helianthinin. It is soluble in diluted salt solutions or may be extracted under alkaline conditions. The other important fraction is the 2S albumin fraction, or sunflower albumins (SFAs), which consists of proteins that are water soluble under a wide pH range.

[0013]

[0012] The globulin extractability increases with increasing pH. However, extraction of proteins at very high pH values (above pH 11.0) is generally not recommended because under these conditions, proteins could be chemically altered. Applying a high pH also risks the generation of unwanted side reactions such as the aforementioned dark color formation from the oxidation of polyphenols and the formation of complexes with proteins. Under these conditions, the hydrolysis of amino acids and peptides increases rapidly. These side reactions negatively impact protein quality and production yield and determine the final products’ functional and sensorial (color and taste) properties.

[0014]

[0013] It is thus an object of the present invention to provide a high yield, robust, cost-efficient industrial process to produce a protein isolate with a mild taste, light color, high production rate and with such functional properties that make it appropriate for the use in foodstuffs (such as in alternative meats or as an emulsifier or stabilizer in dairy applications). It is a further object to provide a precipitated globulin-type sunflower protein isolate and a water-soluble albumin-type of sunflower protein isolate, having a light color, mild taste, and high functionality.

[0015] SUMMARY OF THE INVENTION

[0016]

[0014] In one aspect, the present disclosure is directed to a process for obtaining sunflower protein isolate, wherein the process comprises the following steps: (1) dehulling the sunflower seed to form dehulled sunflower kernels wherein the sunflower kernels comprise oil, protein, fibers, sugars and polyphenols; (2) cold pre-pressing the dehulled sunflower kernels to form a pressed cake wherein the temperature of the dehulled kernels and pressed cake is 65°C or less; (3) processing the pressed cake by extracting oil therefrom with an oil extraction solvent to form an extracted pressed cake; (4) desolventizing the extracted pressed cake to form sunflower protein flour; (5) mixing the sunflower protein flour with water and a reducing agent to form a first suspension and adjusting the pH value of the first suspension to from 8.0 to 11.0; (6) separating the first suspension to form a first liquid fraction comprising sunflower protein and a first solid fraction comprising fiber; (7) mixing the first solid fraction comprising fiber with water and optionally a reducing agent to form a second suspension and adjusting the pH value of the second suspension to from 10.0 to 12.0; (8) separating the second suspension to form a second liquid fraction comprising sunflower protein and a second solid fraction comprising fiber; and (9) obtaining sunflower protein isolate by isolation and / or purification from the first liquid fraction, the second liquid fraction or the combination thereof.

[0017]

[0015] In another aspect, the present disclosure is directed to a sunflower globulin protein isolate obtained by the process for obtaining sunflower protein isolate as disclosed herein, having a protein content of at least 85% on a dry basis; and / or a protein dispersibility index (PDI) of at least 5; and / or a water holding capacity, in gram per gram (g / g), of from 1 to 6; and / or an oil holding capacity, in gram per gram (g / g), of from 0.5 to 3; and / or an emulsion capacity, in gram of oil per gram of protein, of from 100 to 500; and / or an L* value measure in the CIELAB color space of at least 71; and / or an a* value measure in the CIELAB color space of from -2.0 to +4.5; and / or a b* value measure in the CIELAB color space of from -2.0 to +15.0.

[0018]

[0016] In yet another aspect, the present disclosure is directed to a sunflower albumin protein isolate obtained by the process for obtaining sunflower protein isolate as disclosed herein, having a protein content of at least 85% on a dry basis; and / or a protein dispersibility index (PDI) of at least 20; and / or a water holding capacity, in gram per gram (g / g), of from 0 to 5; and / or an oil holding capacity, in gram per gram (g / g), of from 0.5 to 8; and / or an emulsion capacity, in gram of oil per gram of protein, of from 50 to 300; and / or an L* value measure in the CIELAB color space of at least 70; and / or an a* value measure in the CIELAB color space of from -2.0 to +3.0; and / or a b* value measure in the CIELAB color space of from -2.0 to +15.0.

[0019]

[0017] In yet another aspect, the present disclosure is directed to a use of the sunflower globulin protein isolate or the sunflower albumin protein isolate as disclosed herein in a food application.

[0020]

[0018] These and other features of the present disclosure will become apparent to one skilled in the art upon review of the following detailed description when taken in conjunction with the appended claims.

[0021] BRIEF DESCRIPTION OF THE DRAWINGS

[0019] While the specification concludes with claims particularly pointing out and distinctly claiming the invention, it is believed that the invention will be better understood from the following description of the accompanying figures.

[0022]

[0020] FIG. 1 provides the process schema of an aspect of the process starting from step (5) of the process for obtaining sunflower protein isolates (sunflower globulin protein isolate and sunflower albumin protein isolate) as disclosed herein.

[0023] DETAILED DESCRIPTION OF THE INVENTION

[0024]

[0021] Definitions

[0025]

[0022] As used herein, articles such as "a" and "an" when used in a claim, are understood to mean one or more of what is claimed or described.

[0026]

[0023] As used herein, the term “about” to modify a number is meant to include the number recited plus or minus 10%, preferably 5% or preferably 2%. Where legally permissible recitation of a value in a claim means about the value. Use of about in a claim or in the specification is not intended to limit the full scope of covered equivalents.

[0027]

[0024] As used herein, the terms "include", "includes" and "including" are meant to be nonlimiting.

[0028]

[0025] As used herein, the term “reducing agent” (also known as “reductant”, “reducer” or “electron donor”) refers to a chemical species that donates an electron to an oxidizing agent (also known as “electron recipient”, “oxidant”, “oxidizer” or “electron acceptor”). Common examples of reducing agents include alkali metals, formic acid, oxalic acid, ascorbic acid and sulfite compounds.

[0029]

[0026] As used herein, “Protein Dispersibility Index” or “PDI” refers to the amount of dispersible (soluble) protein relative to the overall amount of protein within a material. PDI is measured based on AOCS Standard Procedure Ba 10b-09 Protein Dispersibility Index according to Kjeldahl method.

[0030]

[0027] As used herein, “Water Holding Capacity” or “WHC” refers to hydration capacity and is characterized by the amount of water held by a protein powder or solid material in the presence of excess water. WHC is typically expressed in grams of water per grams of sample. WHC can be measured based on the American Association of Cereal Chemists, AACC 10th edition, method 56-20, “Hydration capacity of pregelatinized cereal products”. The water holding capacity is expressed in gram of bound water (determined via the weight of the water- saturated sediment minus the weight of the dry preparation) per gram of dry protein preparation.

[0028] As used herein, “Oil Holding Capacity” or “OHC” refers to the amount of oil held by a protein powder or solid material in the presence of excess oil. To determine, 2,00 g of the dry matter of the protein sample (using an analytical balance) is weighted into a 50 mL centrifuge tube and 20 g of com germ oil is added. The suspension is shaken in a vortex mixer for 1 minute at a rate of 500 rpm. The sample is then centrifuged at 700 G-force for 15 minutes at 20 °C. The supernatant is carefully drained, and the gross weight of the wet protein is measured. Oil Holding Capacity is expressed in grams of bound oil per gram of dry protein composition, represented by the formula: Mass of wet pellet g) - Initial dry mass of protein sample g) Initial dry mass content of the protein g)

[0031]

[0029] As used herein, “Emulsion Capacity” refers to the maximum amount of oil that can be emulsified in a 1% protein suspension. To determine emulsion capacity, 100 mL of 1% protein containing aqueous suspension is prepared. Proteins are hydrated by magnetic mixer at 300 rpm for 60 min at room temperature. Then, 5.00 g of the protein suspension is weighted into a 50 mL centrifuge tube, after which 10.00 g oil is added into the test tube and the homogenizer probe is placed into the tube, so that the bottom of the probe blade is positioned at the wateroil interface. Homogenization is kept for 3 min at speed 4 and the conductivity of the emulsion is measured and recorded. If conductivity is higher than 2 pS / cm and there is no phase inversion, the protein suspension is still able to emulsify more oil. A new sample with more oil is then prepared. The sample is homogenized the conductivity of the emulsion is measured again. If conductivity is 0 pS / cm and phase inversion happens, then the protein suspension cannot emulsify that amount of oil and a new sample with less oil content is then prepared. The maximum emulsion capacity can be evaluated by detecting conductivity drop to 0-2 pS / cm and phase inversion happens. Emulsion capacity can be represented by the following formula:

[0032]

[0030] As used herein, dry matter % (dm%) refers to weight percent on a dry matter basis.

[0033]

[0031] As used herein, the term “mol / L” refers to moles per liter.

[0034]

[0032] As is known in the art, the Hunterlab colorimeter is a tristimulus instrument that measures color in L*, a*, and b* values by using a filter that spectrally approximates the CIE Standard Observer functions of the eye. The L*, a*, and b* scales give measurements of color in visual units of color perception that relate to perceived color and color difference. The lightness value, L* defines black at 0 and white at 100. The a* axis is relative to the green-red opponent colors, with negative values toward green and positive values toward red. The b* axis represents the blue-yellow opponents, with negative numbers toward blue and positive toward yellow.

[0035]

[0033] Process for obtaining sunflower protein isolate

[0036]

[0034] The present disclosure is directed to a process for obtaining sunflower protein isolate, wherein the process comprises the following steps: (1) dehulling the sunflower seed to form dehulled sunflower kernels wherein the sunflower kernels comprise oil, protein, fibers, sugars and polyphenols; (2) cold pre-pressing the dehulled sunflower kernels to form a pressed cake wherein the temperature of the dehulled kernels and pressed cake is 65°C or less; (3) processing the pressed cake by extracting oil therefrom with an oil extraction solvent to form an extracted pressed cake; (4) desolventizing the extracted pressed cake to form sunflower protein flour; (5) mixing the sunflower protein flour with water and a reducing agent to form a first suspension and adjusting the pH value of the first suspension to from 8.0 to 11.0; (6) separating the first suspension to form a first liquid fraction comprising sunflower protein and a first solid fraction comprising fiber; (7) mixing the first solid fraction comprising fiber with water and optionally a reducing agent to form a second suspension and adjusting the pH value of the second suspension to from 10.0 to 12.0; (8) separating the second suspension to form a second liquid fraction comprising sunflower protein and a second solid fraction comprising fiber; and (9) obtaining sunflower protein isolate by isolation and / or purification from the first liquid fraction, the second liquid fraction or the combination thereof.

[0037]

[0035] Sunflower seeds are dehulled to produce sunflower seed kernels prior to further processing. The dehulling step may suitably be carried out by mechanical treatment methods known in the art such as, for instance and without limitation, impact dehullers and roller mills. In some aspects, impact dehullers are used.

[0038]

[0036] The sunflower seed kernels and the loosened hulls may be separated by classification. Classification may be done by methods known in the art such as, for instance and without limitation, screening, air classification and / or electrostatic separation. Screening includes, without limitation, vibrating screens and rotating drums having a sieve-like structure. Air classification includes, without limitation, air aspiration, rotary classifiers, gravitational classifiers, centrifugal classifiers, and cyclone classifiers.

[0039]

[0037] After classification, some amount of hulls may be left with the seed kernels. The majority of the residual hulls may be optionally removed in an optical sorting step. Optical sorting is known in the art. See, for instance, U.S. Pat. No. 5,733,592, the entire contents of which are incorporated herein. In some such aspects, optical sensors are used to differentiate seed kernels from hulls and other contaminants based on, for instance and without limitation, seed opacity, light reflectance, and light absorbance. In some cases, optical sorting machines use optical sensors that include multiple photodetectors, such as a charged-couple device and photodiode arrays. Such sorting machines may include one or more ejector mechanisms positioned after the sensor. For instance, the ejector mechanism may include multiple air nozzles associated with one or more valves triggered by an electrical signal that is synchronized with the sensor function. In some aspects, a blast of air removes seed kernels that meet, or that do not meet, a pre-defined selection criteria from the flow of the remaining material. In some other aspects, a blast of air removes hull pieces and other contaminants that meet, or that do not meet, a pre-defined selection criteria from the flow of the remaining material.

[0040]

[0038] In a preferred aspect of the present disclosure, the dehulled sunflower kernels comprise a residual hull content of at most 5 wt.%, more preferably from 0.05 wt.% to 5 wt.%, even more preferably from 0.05 wt.% to 3 wt.% and most preferably from 0.05 wt.% to 1 wt.%. Dehulled sunflower purity can be adjusted in the optical sorting unit operation. Under one theory, and without being bound to any particular theory, it is believed that the protein content of the de-oiled and dehulled sunflower kernels is positively correlated with dehulled sunflower purity. The dehulled sunflower kernels further comprise, among other components, oil, protein, sugars, and polyphenols.

[0041]

[0039] The dehulled sunflower kernels are cold pre-pressed to form a pressed cake. Cold presses and associated processing techniques are known in the art. A non-limiting example of a cold press method within the scope of the present disclosure is a screw expeller press. Based on experimental evidence to date, and without being bound to any particular theory, it is believed that the cold pressing unit operation opens up the oil-bearing cells by friction generated in the press thereby preparing the sunflower kernels for efficient solvent extraction of oil, sugars, and other components therefrom.

[0042]

[0040] The temperature of the dehulled kernels and pressed cake in step (2) of the process as disclosed is 65°C or less, preferably from 20°C to 65°C, more preferably from 25°C to 65°C, even more preferably from 35°C to 60°C and most preferably from 40°C to 55°C.

[0043]

[0041] In a preferred aspect, the oil content of the pressed cake in step (2) of the process as disclosed is 65 wt.% on a dry basis or less, more preferably from 20 wt.% to 65 wt.% on a dry basis, even more preferably from 40 wt.% to 65 wt.% on a dry basis and most preferably from 40 wt.% to 50 wt.%, such as from 40 wt.% to 45 wt.%.

[0044]

[0042] In a preferred aspect, the protein content of the pressed cake in step (2) is from 15 wt.% on a dry basis to 40 wt.% on a dry basis, more preferably from 20 wt.% on a dry basis to 35 wt.% on a dry basis and even more preferably from 23 wt.% on a dry basis to 35 wt.% on a dry basis.

[0045]

[0043] In a preferred aspect, the water content of the pressed cake in step (2) is from 2 wt.% to 12 wt.% and more preferably from 4 wt.% to 10 wt.%

[0046]

[0044] In a preferred aspect, the protein dispersibility index (PDI) of the pressed cake in step (3) is from 30% to 45%, more preferably from 35% to 45% and even more preferably from 37% to 43%.

[0047]

[0045] Those skilled in the art would be enabled to optimize the cold pressing process variables necessary to achieve the pressed cake temperature and oil content ranges described herein. For instance, as demonstrated in the examples, screw expeller press shaft speed and cone setting may be suitably varied to produce a pressed cake having a residual oil content having the values and ranges within the scope of the present disclosure. Shaft speed controls seed kernel feed rate into the press, such as by way of a screw feeder. Cone setting sets the discharge area of the press resulting in the applied pressure increase needed to extract oil from the seed kernels. In presses utilizing a die at the discharge, the feed range and die opening size and opening conformation can be suitably selected to obtain a pressed cake having the required oil content. Further, certain press components, such as the discharge barrel and / or feed screws, can be cooled or heated in order to achieve cold press discharge temperatures within the scope of the present disclosure.

[0048]

[0046] Oil extraction may be done by extraction methods known in the art. In a preferred aspect, immersion extraction is used. In some aspects, continuous immersion extraction may be done. In some aspects, countercurrent immersion extraction may be done. In a preferred aspect, multi-stage extractions may be done.

[0049]

[0047] The oil extraction solvent may be a non-polar solvent (e.g., hexane) or a highly concentrated polar protic solvent (e.g., a Cl -3 alcohol, such as > 95% ethanol) considered acceptable for food grain processing. In a preferred aspect, the oil extraction solvent is hexane or ethanol or a combination thereof. In a more preferred aspect, the oil extraction solvent is hexane. In a preferred aspect, oil extraction solvent purity is at least 95 v / v%. Oil extraction is preferably done at a temperature of at most 65°C, more preferably at most 60°C, even more preferably at most 55°C and most preferably at most 45°C.

[0050]

[0048] Immersion extraction is known in the art. See, for instance, U.S. Patent No., 6,495,044 and U.S. Application Publication No. 2016 / 0376204, the entire contents of each of which are incorporated herein. Varying immersion extractor designs are suitable for the practice of the process as disclosed herein. One non-limiting example of an immersion extractor comprises a vertical cylindrical vessel having a series of slowly rotating horizontal plates used for countercurrent extraction. In such extractors, pressed cake is continuously fed to the top of the column and are caused to fall through an opening onto each plate beneath in succession. The solvent is introduced at the bottom of the column and flows counter-currently upward and exiting the at the top of the column. Another non-limiting example of an immersion extractor is a belt-type design where the pressed cake is continuously loaded onto a moving perforated extractor belt to form a bed. The bed height is kept relatively consistent by feed rate adjustment. In some such extractors, countercurrent operation involves spraying fresh extraction solvent onto the pressed cake at the section nearest the discharge end of the extractor. The first extract is collected at the bottom of that section and sequentially pumped over preceding sections to the section having the freshly loaded pressed cake. A non-limiting example of one immersion extractor is the Model IV manufactured by the Crown Iron Works (Minneapolis, MN). In certain countercurrent oil extraction aspects of the process as disclosed herein preferably at least two, more preferably at least four and even more preferably at least seven sequential extractions may be done.

[0051]

[0049] The solids to oil extraction solvent ratio is preferably from 1 :2 to 1 : 15, more preferably from 1 :3 to 1 : 10 and even more preferably from 1 :5 to 1 : 10.

[0052]

[0050] The extracted pressed cake is desolventized to form sunflower protein flour. Desolventization for the extracted press cake, as well as any other steps of the process as disclosed herein, may suitably be done by methods known in the art, such as, and without limitation, heating under partial vacuum. Suitable techniques may employ high temperatureshort time and / or low temperature-long time strategies to minimize protein dispersibility index (PDI) drop during the process. In the high temperature- short time desolventization (flash desolventization), the extracted pressed cake is, preferably subjected to an initial temperature of 200°C or less, more preferably 190°C or less, even more preferably 170°C or less and most preferably 150°C or less in a first desolventization step. The solvent-laden extracted pressed cake is preferably subjected to this temperature for 5 seconds or less, thereby evaporating at least 90%, or at least 95% of the initial solvent content. Residual solvent content of the extracted pressed cake is stripped off under vacuum in a secondary vacuum stripping step. This vacuum stripping may be performed preferably at temperatures of 80°C or less, more preferably 70°C or less and even more preferably 55°C or less. In a preferred aspect, the partial vacuum is at most 100 mmHg. In a more preferred aspect, the partial vacuum is at most 20 mmHg. The total time to achieve final specification solvent limits can vary from 30 minutes up to 60 minutes for both stages.

[0051] In the low temperature-long time desolventization, the extracted pressed cake is desolventized preferably at a temperature of 95°C or less, more preferably 80°C or less, even more preferably 70°C or less and most preferably 60°C or less, preferably for 60 minutes or less, more preferably 50 minutes or less, even more preferably 40 minutes or less and most preferably 30 minutes or less under partial vacuum in a first step. This is followed by stripping step to achieve the final specification solvent limit.

[0053]

[0052] The desolventized extracted pressed cake may then be dried by methods known in the art. The desolventized extracted pressed cake may be directly used and / or optionally milled and optionally graded, preferably to an average particle size of less than 500 microns, more preferably less than 400 microns, even more preferably less than 300 microns and most preferably less than 200 microns.

[0054]

[0053] The oil content of the sunflower protein flour obtained in step (4) of the process as disclosed herein is preferably from 0.25 wt.% on a dry basis to 4 wt.% on a dry basis, more preferably from 0.5 wt.% on a dry basis to 3 wt.% on a dry basis, even more preferably from 1 wt.% on a dry basis to 2.5 wt.% on a dry basis and most preferably from 1 wt.% on a dry basis to 2 wt.% on a dry basis.

[0055]

[0054] The protein content of the sunflower protein flour obtained in step (4) of the process as disclosed herein is preferably from 45 wt.% on a dry basis to 70 wt.% on a dry basis, more preferably from 50 wt.% on a dry basis to 65 wt.% on a dry basis , even more preferably from 52 wt.% on a dry basis to 63 wt.% on a dry basis and most preferably 55 wt.% on a dry basis to 60 wt.% on a dry basis.

[0056]

[0055] The sugar content of the sunflower protein flour obtained in step (4) of the process as disclosed herein is preferably from 0.5 wt.% on a dry basis to 10 wt.% on a dry basis, more preferably from 3 wt.% on a dry basis to 10 wt.% on a dry basis, even more preferably from 4 wt.% on a dry basis to 9 wt.% on a dry basis and most preferably from 5 wt.% on a dry basis to 8 wt.% on a dry basis.

[0057]

[0056] The water content of the sunflower protein flour obtained in step (4) of the process as disclosed herein is preferably from 3 wt.% to 15 wt.%, more preferably from 4 wt.% to 14 wt.%, even more preferably from 6 wt.% to 13 wt.% and most preferably from 8 wt.% to 12 wt.%.

[0058]

[0057] The protein dispersibility index (PDI) of the sunflower protein flour obtained in step (4) of the process as disclosed herein is preferably at least 25%, more preferably from 30% to 90%, even more preferably from 35% to 70% and most preferably from 39% to 50%.

[0058] The ash content of the sunflower protein flour obtained in step (4) of the process as disclosed herein is preferably from 3 wt.% on a dry basis to 15 wt.% on a dry basis, more preferably from 4 wt.% on a dry basis to 13 wt.% on a dry basis, even more preferably from 6 wt.% on a dry basis to 12 wt.% on a dry basis and most preferably from 7 wt.% on a dry basis to 10 wt.% on a dry basis.

[0059]

[0059] The sunflower protein flour obtained in step (4) of the process as disclosed herein preferably has a color value L* of at least 65 in units of the L*, a*, b* color scale as measured by a Hunter Labscan Calorimeter using a Hunter Color Flex EZ (or equivalent) to provide a reading in D65 light, with 10° observer response, where the sample is milled to below 100 pm using a UDY Mill (or equivalent), and using a Fisher brand petri dish (stackable lid, polystyrene, Cat. # FB0875712) (or equivalent).

[0060]

[0060] The sunflower protein flour obtained in step (4) of the process as disclosed herein is mixed with water and a reducing agent to form a first suspension where the pH value of the first suspension is adjusted to from 8.0 to 11.0.

[0061]

[0061] Preferably the reducing agent used in step (5) of the process as disclosed herein is an inorganic reducing agent or an organic reducing agent. More preferably, the reducing agent is a sulfite, an organic acid, sodium sulfite, ascorbic acid or an amino acid containing a thiol group, for example, cysteine or gluthathione. Even more preferably, the reducing agent is sodium sulfite.

[0062]

[0062] In a preferred aspect, the reducing agent content in the first suspension of step (5) of the process as disclosed herein is from 0.001 mol / L to 0.100 mol / L, more preferably from 0.001 mol / L to 0.050 mol / L, even more preferably from 0.001 mol / L to 0.020 mol / L and most preferably from 0.001 mol / L to 0.008 mol / L.

[0063]

[0063] Step (5) of the process as disclosed herein is carried out preferably at a temperature of from 25°C to 65°C, more preferably at a temperature of from 35°C to 60°C, even more preferably at a temperature of from 45°C to 60°C and most preferably at a temperature of from 50°C to 60°C.

[0064]

[0064] The weight ratio of the sunflower protein flour to water in the first suspension of step (5) of the process as disclosed herein is preferably from 1 :5 to 1 : 15, more preferably from 1 :6 to 1 : 14, even more preferably from 1 :7 to 1 : 12 and most preferably from 1 :8 to 1 : 11.

[0065]

[0065] The first suspension of step (5) of the process as disclosed herein is preferably held at a pH value of from 8.0 to 10.0 for 5 minutes to 60 minutes, more preferably held at a pH value of from 8.0 to 10.0 for 10 minutes to 30 minutes.

[0066] The first suspension of step (5) is separated to form a first liquid fraction comprising sunflower protein and a first solid fraction comprising fiber.

[0066]

[0067] The first solid fraction comprising fiber is mixed with water and optionally a reducing agent to form a second suspension where the pH value of the second suspension is adjusted to from 10.0 to 12.0.

[0067]

[0068] Preferably, a reducing agent is used in step (7) of the process as disclosed herein and the reducing agent used in step (7) of the process as disclosed herein is an inorganic reducing agent or an organic reducing agent. More preferably, the reducing agent is a sulfite, an organic acid, sodium sulfite, ascorbic acid or an amino acid containing a thiol group, for example, cysteine or gluthathione. Even more preferably, the reducing agent is sodium sulfite.

[0068]

[0069] In a preferred aspect, the reducing agent content in the first suspension of step (7) of the process as disclosed herein is at most 0.040 mol / L.

[0069]

[0070] Step (7) of the process as disclosed herein is carried out preferably at a temperature of from 25°C to 65°C, more preferably at a temperature of from 35°C to 60°C, even more preferably at a temperature of from 45°C to 60°C and most preferably at a temperature of from 50°C to 60°C.

[0070]

[0071] The weight ratio of the first solid fraction comprising fiber to water in the second suspension of step (7) of the process as disclosed herein is preferably from 1 : 1 to 1 :5.

[0071]

[0072] The first suspension of step (5) of the process as disclosed herein is preferably held by the pH value of from 10.0 to 12.0 for 1 minute to 60 minutes, more preferably held by the pH value of from 10.0 to 12.0 for 1 minute to 10 minutes.

[0072]

[0073] In a preferred aspect, the process for obtaining sunflower protein isolate as disclosed herein comprises the following steps: (1) dehulling the sunflower seed to form dehulled sunflower kernels wherein the sunflower kernels comprise oil, protein, fibers, sugars and polyphenols; (2) cold pre-pressing the dehulled sunflower kernels to form a pressed cake wherein the temperature of the dehulled kernels and pressed cake is from 20°C to 65°C and wherein the oil content of the pressed cake is 65 wt.% on a dry basis or less; (3) processing the pressed cake by extracting oil therefrom with an oil extraction solvent to form an extracted pressed cake; (4) desolventizing the extracted pressed cake to form sunflower protein flour wherein the protein dispersibility index (PDI) of the sunflower protein flour is at least 25% and the protein content of the sunflower protein flour is from 45 wt.% on a dry basis to 70 wt.% on a dry basis; (5) mixing the sunflower protein flour with water and a reducing agent to form a first suspension and adjusting the pH value of the first suspension to from 8.0 to 11.0 for from 5 minutes to 60 minutes at a temperature of from 25°C to 65°C wherein the weight ratio of the sunflower protein flour to water in the first suspension is from 1 :5 to 1 :15 and the reducing agent content in the first suspension is from 0.001 mol / L to 0.100 mol / L; (6) separating the first suspension to form a first liquid fraction comprising sunflower protein and a first solid fraction comprising fiber; (7) mixing the first solid fraction comprising fiber with water and a reducing agent to form a second suspension and adjusting the pH value of the second suspension to from 10.0 to 12.0 at a temperature of from 25°C to 65°C wherein the weight ratio of the first solid fraction comprising fiber to water in the first suspension is from 1 : 1 to 1 :5; (8) separating the second suspension to form a second liquid fraction comprising sunflower protein and a second solid fraction comprising fiber; and (9) obtaining sunflower protein isolate by isolation and / or purification from the first liquid fraction, the second liquid fraction or the combination thereof.

[0073]

[0074] In a more preferred aspect, the process for obtaining sunflower protein isolate as disclosed herein comprises the following steps: (1) dehulling the sunflower seed to form dehulled sunflower kernels wherein the sunflower kernels comprise oil, protein, fibers, sugars and polyphenols; (2) cold pre-pressing the dehulled sunflower kernels to form a pressed cake wherein the temperature of the dehulled kernels and pressed cake is from 25°C to 65°C and wherein the oil content of the pressed cake is from 20 wt% on a dry basis and 65 wt.% on a dry basis; (3) processing the pressed cake by extracting oil therefrom with an oil extraction solvent to form an extracted pressed cake; (4) desolventizing the extracted pressed cake to form sunflower protein flour wherein the protein dispersibility index (PDI) of the sunflower protein flour is from 30% to 90% and the protein content of the sunflower protein flour is from 50 wt.% on a dry basis to 65 wt.% on a dry basis; (5) mixing the sunflower protein flour with water and a reducing agent to form a first suspension and adjusting the pH value of the first suspension to from 8.0 to 10.0 for from 5 minutes to 60 minutes at a temperature of from 35°C to 60°C wherein the weight ratio of the sunflower protein flour to water in the first suspension is from 1 :6 to 1 : 14 and the reducing agent content in the first suspension is from 0.001 mol / L to 0.050 mol / L; (6) separating the first suspension to form a first liquid fraction comprising sunflower protein and a first solid fraction comprising fiber; (7) mixing the first solid fraction comprising fiber with water and a reducing agent to form a second suspension and adjusting the pH value of the second suspension to from 10.0 to 12.0 for from 1 minute to 60 minutes at a temperature of from 35°C to 60°C wherein the weight ratio of the first solid fraction comprising fiber to water in the first suspension is from 1 : 1 to 1 :5 the reducing agent content in the first suspension is at most 0.004 mol / L; (8) separating the second suspension to form a second liquid fraction comprising sunflower protein and a second solid fraction comprising fiber; and (9) obtaining sunflower protein isolate by isolation and / or purification from the first liquid fraction, the second liquid fraction or the combination thereof

[0074]

[0075] In an even more preferred aspect, the process for obtaining sunflower protein isolate as disclosed herein comprises the following steps: (1) dehulling the sunflower seed to form dehulled sunflower kernels wherein the sunflower kernels comprise oil, protein, fibers, sugars and polyphenols; (2) cold pre-pressing the dehulled sunflower kernels to form a pressed cake wherein the temperature of the dehulled kernels and pressed cake is from 35°C to 60°C and wherein the oil content of the pressed cake is from 40 wt% on a dry basis and 65 wt.% on a dry basis; (3) processing the pressed cake by extracting oil therefrom with an oil extraction solvent to form an extracted pressed cake; (4) desolventizing the extracted pressed cake to form sunflower protein flour wherein the protein dispersibility index (PDI) of the sunflower protein flour is from 35% to 70% and the protein content of the sunflower protein flour is from 52 wt.% on a dry basis to 63 wt.% on a dry basis; (5) mixing the sunflower protein flour with water and a reducing agent to form a first suspension and adjusting the pH value of the first suspension to from 8.0 to 10.0 for from 10 minutes to 30 minutes at a temperature of from 45°C to 60°C wherein the weight ratio of the sunflower protein flour to water in the first suspension is from 1 :7 to 1 : 12 and the reducing agent content in the first suspension is from 0.001 mol / L to 0.020 mol / L; (6) separating the first suspension to form a first liquid fraction comprising sunflower protein and a first solid fraction comprising fiber; (7) mixing the first solid fraction comprising fiber with water and a reducing agent to form a second suspension and adjusting the pH value of the second suspension to from 10.0 to 12.0 for from 1 minute to 10 minutes at a temperature of from 45°C to 60°C wherein the weight ratio of the first solid fraction comprising fiber to water in the first suspension is from 1 : 1 to 1 :5 the reducing agent content in the first suspension is at most 0.004 mol / L; (8) separating the second suspension to form a second liquid fraction comprising sunflower protein and a second solid fraction comprising fiber; and (9) obtaining sunflower protein isolate by isolation and / or purification from the first liquid fraction, the second liquid fraction or the combination thereof.

[0075]

[0076] In a most preferred aspect, the process for obtaining sunflower protein isolate as disclosed herein comprises the following steps: (1) dehulling the sunflower seed to form dehulled sunflower kernels wherein the sunflower kernels comprise oil, protein, fibers, sugars and polyphenols; (2) cold pre-pressing the dehulled sunflower kernels to form a pressed cake wherein the temperature of the dehulled kernels and pressed cake is from 40°C to 55°C and wherein the oil content of the pressed cake is from 40 wt% on a dry basis and 50 wt.% on a dry basis; (3) processing the pressed cake by extracting oil therefrom with an oil extraction solvent to form an extracted pressed cake; (4) desolventizing the extracted pressed cake to form sunflower protein flour wherein the protein dispersibility index (PDI) of the sunflower protein flour is from 39% to 50% and the protein content of the sunflower protein flour is from 55 wt.% on a dry basis to 60 wt.% on a dry basis; (5) mixing the sunflower protein flour with water and a reducing agent to form a first suspension and adjusting the pH value of the first suspension to from 8.0 to 10.0 for from 10 minutes to 30 minutes at a temperature of from 50°C to 60°C wherein the weight ratio of the sunflower protein flour to water in the first suspension is from 1 :8 to 1 : 11 and the reducing agent content in the first suspension is from 0.001 mol / L to 0.008 mol / L; (6) separating the first suspension to form a first liquid fraction comprising sunflower protein and a first solid fraction comprising fiber; (7) mixing the first solid fraction comprising fiber with water and a reducing agent to form a second suspension and adjusting the pH value of the second suspension to from 10.0 to 12.0 for from 1 minute to 10 minutes at a temperature of from 50°C to 60°C wherein the weight ratio of the first solid fraction comprising fiber to water in the first suspension is from 1 : 1 to 1 :5 the reducing agent content in the first suspension is at most 0.004 mol / L; (8) separating the second suspension to form a second liquid fraction comprising sunflower protein and a second solid fraction comprising fiber; and (9) obtaining sunflower protein isolate by isolation and / or purification from the first liquid fraction, the second liquid fraction or the combination thereof.

[0076]

[0077] When the process as disclosed herein is for obtaining sunflower protein isolate, which is sunflower globulin protein isolate or sunflower albumin protein isolate, the step (9) of the process as disclosed herein preferably comprises: (a) adjusting the pH value of the first liquid fraction, the second liquid fraction or the combination thereof to form 3.0 to 6.0, more preferably from 4.0 to 5.0 at a temperature of from 25°C to 65°C, more preferably from 50°C to 60°C to form a globulin protein solid fraction and an albumin protein liquid fraction; (b) washing the globulin protein solid fraction at a pH value of from 3.0 to 6.0, more preferably from 4.0 to 5.0 where the weight ratio of the globulin protein solid fraction to water is from 1 : 1 to 1 :5, more preferably from 1 : 1.5 to 1 :3; (c) separating a globulin protein washed solid fraction and an albumin protein wash liquid fraction; and (d) clarifying the albumin protein liquid fraction, the albumin protein wash liquid fraction or the combination thereof, for example by centrifuge to form a clarified globulin protein solid fraction and a clarified albumin protein liquid fraction.

[0077]

[0078] When the process as disclosed herein is for obtaining sunflower protein isolate, which is sunflower globulin protein isolate, the step (9) of the process as disclosed herein preferably further comprises: (el) homogenizing the globulin protein washed solid fraction, the clarified globulin protein solid fraction or the combination thereof with water to form a globulin protein suspension with a dry matter content of from 10% to 20% by weight, more preferably from 11% to 15% by weight; (fl) adjusting the pH value of the globulin protein suspension to from 4.5 to 8.0, preferably from 5.0 to 7.5; (gl) optionally, heat-treating the pH adjusted globulin protein suspension at a temperature of from 60°C to 160°C, more preferably from 100°C to 150°C for from 5 seconds to 60 seconds; and (hl) obtaining the sunflower globulin protein isolate by drying the globulin protein suspension, such as by spray-draying.

[0078]

[0079] When the process as disclosed herein is for obtaining sunflower protein isolate, which is sunflower albumin protein isolate, the step (9) of the process as disclosed herein preferably further comprises: (e2) filtrating the clarified albumin protein liquid fraction, for example by membrane filtration, more preferably by a pH value of from 3.0 to 6.0, to form a filtrated albumin protein liquid fraction and an impurity fraction comprising polyphenols and sugars; (f2) homogenizing the filtrated albumin protein liquid fraction with water to form an albumin protein suspension with a dry matter content of from 10% to 20% by weight, more preferably from 11% to 15% by weight; (g2) adjusting the pH value of the albumin protein suspension to from 4.5 to 8.0, more preferably from 5.0 to 7.5; (h2) optionally, heat-treating the pH adjusted albumin protein suspension at a temperature of from 60°C to 160°C, more preferably from 100°C to 150°C for from 5 seconds to 60 seconds; and (i2) obtaining the sunflower albumin protein isolate by drying the albumin protein suspension, such as by spray-draying.

[0079]

[0080] Membrane filtration is a very efficient way to purify and concentrate proteins. If the inlet liquid material is clarified from oil residues and solid particles, then there is a lower chance that the membrane fouls. Membrane filtration is a costly process, and only works properly if membrane fouling can be avoided by efficient membrane washing steps.

[0080]

[0081] In a preferred aspect, the process for obtaining sunflower globulin protein isolate as disclosed herein comprises the following steps: (1) dehulling the sunflower seed to form dehulled sunflower kernels wherein the sunflower kernels comprise oil, protein, fibers, sugars and polyphenols; (2) cold pre-pressing the dehulled sunflower kernels to form a pressed cake wherein the temperature of the dehulled kernels and pressed cake is from 35°C to 60°C and wherein the oil content of the pressed cake is from 40 wt% on a dry basis and 65 wt.% on a dry basis; (3) processing the pressed cake by extracting oil therefrom with an oil extraction solvent to form an extracted pressed cake; (4) desolventizing the extracted pressed cake to form sunflower protein flour wherein the protein dispersibility index (PDI) of the sunflower protein flour is from 35% to 70% and the protein content of the sunflower protein flour is from 52 wt.% on a dry basis to 63 wt.% on a dry basis; (5) mixing the sunflower protein flour with water and a reducing agent to form a first suspension and adjusting the pH value of the first suspension to from 8.0 to 10.0 for from 10 minutes to 30 minutes at a temperature of from 45°C to 60°C wherein the weight ratio of the sunflower protein flour to water in the first suspension is from 1 :7 to 1 : 12 and the reducing agent content in the first suspension is from 0.001 mol / L to 0.100 mol / L; (6) separating the first suspension to form a first liquid fraction comprising sunflower protein and a first solid fraction comprising fiber; (7) mixing the first solid fraction comprising fiber with water and a reducing agent to form a second suspension and adjusting the pH value of the second suspension to from 10.0 to 12.0 for from 1 minute to 10 minutes at a temperature of from 45°C to 60°C wherein the weight ratio of the first solid fraction comprising fiber to water in the first suspension is from 1 : 1 to 1 :5 the reducing agent content in the first suspension is at most 0.004 mol / L; (8) separating the second suspension to form a second liquid fraction comprising sunflower protein and a second solid fraction comprising fiber; and (9) obtaining sunflower protein isolate by isolation and / or purification from the first liquid fraction, the second liquid fraction or the combination thereof, wherein step (9) of the process comprise (a) adjusting the pH value of the first liquid fraction, the second liquid fraction or the combination thereof to from 3.0 to 6.0 at a temperature of from 25°C to 65°C to form a globulin protein solid fraction and an albumin protein liquid fraction; (b) washing the globulin protein solid fraction at a pH value of from 3.0 to 6.0 where the weight ratio of the globulin protein solid fraction to water is from 1 : 1 to 1 :5; (c) separating a globulin protein washed solid fraction and an albumin protein wash liquid fraction; (d) clarifying the albumin protein liquid fraction, the albumin protein wash liquid fraction or the combination thereof by centrifuge to form a clarified globulin protein solid fraction and a clarified albumin protein liquid fraction; (el) homogenizing the globulin protein washed solid fraction, the clarified globulin protein solid fraction or the combination thereof with water to form a globulin protein suspension with a dry matter content of from 10% to 20% by weight; (fl) adjusting the pH value of the globulin protein suspension to from 4.5 to 8.0; (gl) heat-treating the pH adjusted globulin protein suspension at a temperature of from 60°C to 160°C for from 5 seconds to 60 seconds; and (hl) obtaining the sunflower globulin protein isolate by spray-drying the globulin protein suspension.

[0081]

[0082] In a more preferred aspect, the process for obtaining sunflower globulin protein isolate as disclosed herein comprises the following steps: (1) dehulling the sunflower seed to form dehulled sunflower kernels wherein the sunflower kernels comprise oil, protein, fibers, sugars and polyphenols; (2) cold pre-pressing the dehulled sunflower kernels to form a pressed cake wherein the temperature of the dehulled kernels and pressed cake is from 40°C to 55°C and wherein the oil content of the pressed cake is from 40 wt% on a dry basis and 50 wt.% on a dry basis; (3) processing the pressed cake by extracting oil therefrom with an oil extraction solvent to form an extracted pressed cake; (4) desolventizing the extracted pressed cake to form sunflower protein flour wherein the protein dispersibility index (PDI) of the sunflower protein flour is from 39% to 50% and the protein content of the sunflower protein flour is from 55 wt.% on a dry basis to 60 wt.% on a dry basis; (5) mixing the sunflower protein flour with water and a reducing agent to form a first suspension and adjusting the pH value of the first suspension to from 8.0 to 10.0 for from 10 minutes to 30 minutes at a temperature of from 50°C to 60°C wherein the weight ratio of the sunflower protein flour to water in the first suspension is from 1 :8 to 1 : 11 and the reducing agent content in the first suspension is from 0.001 mol / L to 0.050 mol / L; (6) separating the first suspension to form a first liquid fraction comprising sunflower protein and a first solid fraction comprising fiber; (7) mixing the first solid fraction comprising fiber with water and a reducing agent to form a second suspension and adjusting the pH value of the second suspension to from 10.0 to 12.0 for from 1 minute to 10 minutes at a temperature of from 50°C to 60°C wherein the weight ratio of the first solid fraction comprising fiber to water in the first suspension is from 1 : 1 to 1 :5 the reducing agent content in the first suspension is at most 0.004 mol / L; (8) separating the second suspension to form a second liquid fraction comprising sunflower protein and a second solid fraction comprising fiber; and (9) obtaining sunflower protein isolate by isolation and / or purification from the combination of the first liquid fraction and the second liquid fraction, wherein step (9) of the process comprise (a) adjusting the pH value of the combination of the first liquid fraction and the second liquid fraction to from 4.0 to 5.0 at a temperature of from 50°C to 60°C to form a globulin protein solid fraction and an albumin protein liquid fraction; (b) washing the globulin protein solid fraction at a pH value of from 4.0 to 5.0 where the weight ratio of the globulin protein solid fraction to water is from 1 : 1.5 to 1 :3; (c) separating a globulin protein washed solid fraction and an albumin protein wash liquid fraction; (d) clarifying the combination of the albumin protein liquid fraction and the albumin protein wash liquid fraction by centrifuge to form a clarified globulin protein solid fraction and a clarified albumin protein liquid fraction; (el) homogenizing the combination of the globulin protein washed solid fraction and the clarified globulin protein solid fraction with water to form a globulin protein suspension with a dry matter content of from 11% to 15% by weight; (fl) adjusting the pH value of the globulin protein suspension to from 5.0 to 7.5; (gl) heat-treating the pH adjusted globulin protein suspension at a temperature of from 60°C to 160°C for from 5 seconds to 60 seconds; and (hl) obtaining the sunflower globulin protein isolate by spray-drying the globulin protein suspension.

[0082]

[0083] In a preferred aspect, the process for obtaining sunflower albumin protein isolate as disclosed herein comprises the following steps: (1) dehulling the sunflower seed to form dehulled sunflower kernels wherein the sunflower kernels comprise oil, protein, fibers, sugars and polyphenols; (2) cold pre-pressing the dehulled sunflower kernels to form a pressed cake wherein the temperature of the dehulled kernels and pressed cake is from 35°C to 60°C and wherein the oil content of the pressed cake is from 40 wt% on a dry basis and 65 wt.% on a dry basis; (3) processing the pressed cake by extracting oil therefrom with an oil extraction solvent to form an extracted pressed cake; (4) desolventizing the extracted pressed cake to form sunflower protein flour wherein the protein dispersibility index (PDI) of the sunflower protein flour is from 35% to 70% and the protein content of the sunflower protein flour is from 52 wt.% on a dry basis to 63 wt.% on a dry basis; (5) mixing the sunflower protein flour with water and a reducing agent to form a first suspension and adjusting the pH value of the first suspension to from 8.0 to 10.0 for from 10 minutes to 30 minutes at a temperature of from 45°C to 60°C wherein the weight ratio of the sunflower protein flour to water in the first suspension is from 1 :7 to 1 : 12 and the reducing agent content in the first suspension is from 0.001 mol / L to 0.100 mol / L; (6) separating the first suspension to form a first liquid fraction comprising sunflower protein and a first solid fraction comprising fiber; (7) mixing the first solid fraction comprising fiber with water and a reducing agent to form a second suspension and adjusting the pH value of the second suspension to from 10.0 to 12.0 for from 1 minute to 10 minutes at a temperature of from 45°C to 60°C wherein the weight ratio of the first solid fraction comprising fiber to water in the first suspension is from 1 : 1 to 1 :5 the reducing agent content in the first suspension is at most 0.004 mol / L; (8) separating the second suspension to form a second liquid fraction comprising sunflower protein and a second solid fraction comprising fiber; and (9) obtaining sunflower protein isolate by isolation and / or purification from the first liquid fraction, the second liquid fraction or the combination thereof, wherein step (9) of the process comprise (a) adjusting the pH value of the first liquid fraction, the second liquid fraction or the combination thereof to from 3.0 to 6.0 at a temperature of from 25°C to 65°C to form a globulin protein solid fraction and an albumin protein liquid fraction; (b) washing the globulin protein solid fraction at a pH value of from 3.0 to 6.0 where the weight ratio of the globulin protein solid fraction to water is from 1 : 1 to 1 :5; (c) separating a globulin protein washed solid fraction and an albumin protein wash liquid fraction; (d) clarifying the albumin protein liquid fraction, the albumin protein wash liquid fraction or the combination thereof by centrifuge to form a clarified globulin protein solid fraction and a clarified albumin protein liquid fraction; (e2) filtrating the clarified albumin protein liquid fraction by membrane filtration by a pH value of from 3.0 to 6.0 to form a filtrated albumin protein liquid fraction and an impurity fraction comprising polyphenols and sugars; (f2) homogenizing the filtrated albumin protein liquid fraction with water to form an albumin protein suspension with a dry matter content of from 10% to 20% by weight; (g2) adjusting the pH value of the albumin protein suspension to from 4.5 to 8.0; (h2) heat-treating the pH adjusted albumin protein suspension at a temperature of from 60°C to 160°C for from 5 seconds to 60 seconds; and (i2) obtaining the sunflower albumin protein isolate by spray-drying the albumin protein suspension.

[0083]

[0084] In a more preferred aspect, the process for obtaining sunflower albumin protein isolate as disclosed herein comprises the following steps: (1) dehulling the sunflower seed to form dehulled sunflower kernels wherein the sunflower kernels comprise oil, protein, fibers, sugars and polyphenols; (2) cold pre-pressing the dehulled sunflower kernels to form a pressed cake wherein the temperature of the dehulled kernels and pressed cake is from 40°C to 55°C and wherein the oil content of the pressed cake is from 40 wt% on a dry basis and 50 wt.% on a dry basis; (3) processing the pressed cake by extracting oil therefrom with an oil extraction solvent to form an extracted pressed cake; (4) desolventizing the extracted pressed cake to form sunflower protein flour wherein the protein dispersibility index (PDI) of the sunflower protein flour is from 39% to 50% and the protein content of the sunflower protein flour is from 55 wt.% on a dry basis to 60 wt.% on a dry basis; (5) mixing the sunflower protein flour with water and a reducing agent to form a first suspension and adjusting the pH value of the first suspension to from 8.0 to 10.0 for from 10 minutes to 30 minutes at a temperature of from 50°C to 60°C wherein the weight ratio of the sunflower protein flour to water in the first suspension is from 1 :8 to 1 : 11 and the reducing agent content in the first suspension is from 0.001 mol / L to 0.050 mol / L; (6) separating the first suspension to form a first liquid fraction comprising sunflower protein and a first solid fraction comprising fiber; (7) mixing the first solid fraction comprising fiber with water and a reducing agent to form a second suspension and adjusting the pH value of the second suspension to from 10.0 to 12.0 for from 1 minute to 10 minutes at a temperature of from 50°C to 60°C wherein the weight ratio of the first solid fraction comprising fiber to water in the first suspension is from 1 : 1 to 1 :5 the reducing agent content in the first suspension is at most 0.004 mol / L; (8) separating the second suspension to form a second liquid fraction comprising sunflower protein and a second solid fraction comprising fiber; and (9) obtaining sunflower protein isolate by isolation and / or purification from the combination of the first liquid fraction and the second liquid fraction, wherein step (9) of the process comprise (a) adjusting the pH value of the combination of the first liquid fraction and the second liquid fraction to from 4.0 to 5.0 at a temperature of from 50°C to 60°C to form a globulin protein solid fraction and an albumin protein liquid fraction; (b) washing the globulin protein solid fraction at a pH value of from 4.0 to 5.0 where the weight ratio of the globulin protein solid fraction to water is from 1 : 1.5 to 1 :3; (c) separating a globulin protein washed solid fraction and an albumin protein wash liquid fraction; (d) clarifying the combination of the albumin protein liquid fraction and the albumin protein wash liquid fraction by centrifuge to form a clarified globulin protein solid fraction and a clarified albumin protein liquid fraction; (e2) filtrating the clarified albumin protein liquid fraction by membrane filtration by a pH value of from 3.0 to 6.0 to form a filtrated albumin protein liquid fraction and an impurity fraction comprising polyphenols and sugars; (f2) homogenizing the filtrated albumin protein liquid fraction with water to form an albumin protein suspension with a dry matter content of from 11% to 15% by weight; (g2) adjusting the pH value of the albumin protein suspension to from 5.0 to 7.5; (h2) heat-treating the pH adjusted albumin protein suspension at a temperature of from 100°C to 150°C for from 5 seconds to 60 seconds; and (i2) obtaining the sunflower albumin protein isolate by spray-drying the albumin protein suspension.

[0084]

[0085] Instead of employing costly methods for the removal of polyphenols or avoidance of polyphenols oxidation like acid extraction, ion exchange resins, or inert gas blankets, or any other costly process steps, the process as disclosed herein achieves excellent results using a second alkaline protein extraction step in the presence of a reducing agent. The process as disclosed herein ensures that the isolated sunflower proteins are light colored and have a mild taste and high functional properties. It also ensures low protein loss into the fiber fraction. The process as disclosed herein is simpler and more cost effective than current methods while still meeting quality standards.

[0085]

[0086] This two-step alkaline protein solubilization process as disclosed herein is important to achieve a higher level of protein functionality and to maximize the production yield of sunflower protein isolates. The first mild alkaline extraction step at a pH value of from 8.0 to 11.0 solubilizes most of the proteins, ensuring high quality of the extracted proteins. The second alkaline extraction step takes place at a relative high pH of from 10.0 to 12.0 in order to increase the protein extraction yield and to minimize the risk of any undesirable side reactions.

[0086]

[0087] Sunflower globulin protein isolate

[0088] In a further aspect, the present disclosure is directed to a sunflower globulin protein isolate obtained by the process disclosed herein.

[0087]

[0089] The sunflower globulin protein isolate obtained by the process as disclosed herein has a protein content of at least 85% on a dry basis, preferably at least 88% on a dry basis, more preferably from 90% to 98% on a dry basis and even more preferably from 90% to 95% on a dry basis.

[0088]

[0090] The sunflower globulin protein isolate obtained by the process as disclosed herein has a protein dispersibility index (PDI) of at least 5, preferably from 10 to 70, more preferably from 15 to 60 and even more preferably from 20 to 55.

[0089]

[0091] The sunflower globulin protein isolate obtained by the process as disclosed herein has a water holding capacity, in gram per gram (g / g), of from 1 to 6, preferably from 1.5 to 5, more preferably from 2 to 4.5 and even more preferably from 2.5 to 4.0.

[0090]

[0092] The sunflower globulin protein isolate obtained by the process as disclosed herein has an oil holding capacity, in gram per gram (g / g), of from 0.5 to 3, preferably from 1.0 to 2.5, more preferably from 1.0 to 2.0 and even more preferably from 1.2 to 1.5.

[0091]

[0093] The sunflower globulin protein isolate obtained by the process as disclosed herein has an emulsion capacity, in gram of oil per gram of protein, of from 100 to 500, preferably from 120 to 450, more preferably from 150 to 400 and even more preferably from 170 to 380.

[0092]

[0094] The sunflower globulin protein isolate obtained by the process as disclosed herein has an L* value measure in the CIELAB color space of at least 71, preferably from 72 to 95, more preferably from 73 to 90 and even more preferably from 74 to 84.

[0093]

[0095] The sunflower globulin protein isolate obtained by the process as disclosed herein has an a* value measure in the CIELAB color space of from -2.0 to +4.5, preferably from -1.0 to +4.0, more preferably from -0.5 to +4.0 and even more preferably from 0.0 to +4.0.

[0094]

[0096] The sunflower globulin protein isolate obtained by the process as disclosed herein has a b* value measure in the CIELAB color space of from -2.0 to +15.0, preferably from -1.0 to +14.0, more preferably from -0.5 to +14.0 and even more preferably from 0.0 to +14.0.

[0095]

[0097] In a preferred aspect, the sunflower globulin protein isolate obtained by the process as disclosed herein has a protein content of at least 85% on a dry basis; a protein dispersibility index (PDI) of at least 5; a water holding capacity, in gram per gram (g / g), of from 1 to 6; an oil holding capacity, in gram per gram (g / g), of from 0.5 to 3; an emulsion capacity, in gram of oil per gram of protein, of from 100 to 500; an L* value measure in the CIELAB color space of at least 71; an a* value measure in the CIELAB color space of from -2.0 to +4.5; and a b* value measure in the CIELAB color space of from -2.0 to +15.0.

[0098] In a more preferred aspect, the sunflower globulin protein isolate obtained by the process as disclosed herein has a protein content of at least 88% on a dry basis; a protein dispersibility index (PDI) of from 10 to 70; a water holding capacity, in gram per gram (g / g), of from 1.5 to 5; an oil holding capacity, in gram per gram (g / g), of from 1.0 to 2.5; an emulsion capacity, in gram of oil per gram of protein, of from 120 to 450; an L* value measure in the CIELAB color space of from 72 to 95; an a* value measure in the CIELAB color space of from -1.0 to +4.0; and a b* value measure in the CIELAB color space of from -1.0 to +14.0.

[0096]

[0099] In an even more preferred aspect, the sunflower globulin protein isolate obtained by the process as disclosed herein has a protein content of from 90% to 98% on a dry basis; a protein dispersibility index (PDI) of from 15 to 60; a water holding capacity, in gram per gram (g / g), of from 2 to 4.5; an oil holding capacity, in gram per gram (g / g), of from 1.0 to 2.0; an emulsion capacity, in gram of oil per gram of protein, of from 150 to 400; an L* value measure in the CIELAB color space of from 73 to 90; an a* value measure in the CIELAB color space of from -0.5 to +4.0; and a b* value measure in the CIELAB color space of from -0.5 to +14.0.

[0097]

[0100] In a most preferred aspect, the sunflower globulin protein isolate obtained by the process as disclosed herein has a protein content of from 90% to 95% on a dry basis; a protein dispersibility index (PDI) of from 20 to 55; a water holding capacity, in gram per gram (g / g), of from 2.5 to 4.0; an oil holding capacity, in gram per gram (g / g), of from 1.2 to 1.5; an emulsion capacity, in gram of oil per gram of protein, of from 170 to 380; an L* value measure in the CIELAB color space of from 74 to 84; an a* value measure in the CIELAB color space of from 0.0 to +4.0; and a b* value measure in the CIELAB color space of from 0.0 to +14.0.

[0098]

[0101] Sunflower albumin protein isolate

[0099]

[0102] In a further aspect, the present disclosure is directed to a sunflower albumin protein isolate obtained by the process disclosed herein.

[0100]

[0103] The sunflower albumin protein isolate obtained by the process as disclosed herein has a protein content of at least 85% on a dry basis, preferably at least 88% on a dry basis, more preferably from 90% to 98% on a dry basis and even more preferably from 92% to 96% on a dry basis.

[0101]

[0104] The sunflower albumin protein isolate obtained by the process as disclosed herein has a protein dispersibility index (PDI) of at least 20, preferably from 30 to 85, more preferably from 40 to 80 and even more preferably from 50 to 78.

[0102]

[0105] The sunflower albumin protein isolate obtained by the process as disclosed herein has a water holding capacity, in gram per gram (g / g), of from 0 to 5, preferably from 0 to 4, more preferably from 0.1 to 2.0 and even more preferably from 0.2 to 0.5.

[0106] The sunflower albumin protein isolate obtained by the process as disclosed herein has an oil holding capacity, in gram per gram (g / g), of from 0.5 to 8, preferably from 2 to 7, more preferably from 3 to 6 and even more preferably from 4 to 6.

[0103]

[0107] The sunflower albumin protein isolate obtained by the process as disclosed herein has an emulsion capacity, in gram of oil per gram of protein, of from 50 to 300, preferably from 80 to 250, more preferably from 100 to 230 and even more preferably from 150 to 210.

[0104]

[0108] The sunflower albumin protein isolate obtained by the process as disclosed herein has an L* value measure in the CIELAB color space of at least 70, preferably from 75 to 98, more preferably from 80 to 95 and even more preferably from 85 to 90.

[0105]

[0109] The sunflower albumin protein isolate obtained by the process as disclosed herein has an a* value measure in the CIELAB color space of from -2.0 to +3.0, preferably from -1.0 to +2.5, more preferably from -0.5 to +2.0 and even more preferably from 0.0 to +2.0.

[0106]

[0110] The sunflower albumin protein isolate obtained by the process as disclosed herein has a b* value measure in the CIELAB color space of from -2.0 to +15.0, preferably from -1.0 to +14.0, more preferably from -0.5 to +13.5 and even more preferably from 0.0 to +13.0.

[0107] [Hl] In a preferred aspect, the sunflower albumin protein isolate obtained by the process as disclosed herein has a protein content of at least 85% on a dry basis; a protein dispersibility index (PDI) of at least 20; a water holding capacity, in gram per gram (g / g), of from 0 to 5; an oil holding capacity, in gram per gram (g / g), of from 0.5 to 8; an emulsion capacity, in gram of oil per gram of protein, of from 50 to 300; an L* value measure in the CIELAB color space of at least 70; an a* value measure in the CIELAB color space of from -2.0 to +3.0; and a b* value measure in the CIELAB color space of from -2.0 to +15.0.

[0108]

[0112] In a more preferred aspect, the sunflower albumin protein isolate obtained by the process as disclosed herein has a protein content of at least 88% on a dry basis; a protein dispersibility index (PDI) of from 30 to 85; a water holding capacity, in gram per gram (g / g), of from 0 to 4; an oil holding capacity, in gram per gram (g / g), of from 2 to 7; an emulsion capacity, in gram of oil per gram of protein, of from 80 to 250; an L* value measure in the CIELAB color space of from 75 to 98; an a* value measure in the CIELAB color space of from -1.0 to +2.5; and a b* value measure in the CIELAB color space of from -1.0 to +14.0.

[0109]

[0113] In an even more preferred aspect, the sunflower albumin protein isolate obtained by the process as disclosed herein has a protein content of from 90% to 98% on a dry basis; a protein dispersibility index (PDI) of from 40 to 80; a water holding capacity, in gram per gram (g / g), of from 0.1 to 2.0; an oil holding capacity, in gram per gram (g / g), of from 3 to 6; an emulsion capacity, in gram of oil per gram of protein, of from 100 to 230; an L* value measure in the CIELAB color space of from 80 to 95; an a* value measure in the CIELAB color space of from -0.5 to +2.0; and a b* value measure in the CIELAB color space of from -0.5 to +13.5.

[0110]

[0114] In a most preferred aspect, the sunflower albumin protein isolate obtained by the process as disclosed herein has a protein content of from 92% to 96% on a dry basis; a protein dispersibility index (PDI) of from 50 to 78; a water holding capacity, in gram per gram (g / g), of from 0.2 to 0.5; an oil holding capacity, in gram per gram (g / g), of from 4 to 6; an emulsion capacity, in gram of oil per gram of protein, of from 150 to 210; an L* value measure in the CIELAB color space of from 85 to 90; an a* value measure in the CIELAB color space of from 0.0 to +2.0; and a b* value measure in the CIELAB color space of from 0.0 to +13.0.

[0111]

[0115] Use of a sunflower globulin protein isolate or a sunflower albumin protein isolate

[0112]

[0116] In a further aspect, the present disclosure is directed to a use of the sunflower globulin protein isolate or the sunflower albumin protein isolate as disclosed herein in a food product. In a further preferred aspect, the present disclosure is directed to a use of the sunflower globulin protein isolate or the sunflower albumin protein isolate as disclosed herein in a confectionery product, a bakery product or a culinary product. In an even more preferred aspect, the present disclosure is directed to a use of the sunflower globulin protein isolate or the sunflower albumin protein isolate as disclosed herein in cake, ice-cream, whipped cream, cheese, plant-based meat, plant-based cheese, plant-based ice-cream or plant-based whipped cream. In a yet even more preferred aspect, the present disclosure is directed to a use of the sunflower globulin protein isolate or the sunflower albumin protein isolate as disclosed herein in plant-based meat such as plant-based bacon, plant-based sausage or plant-based hamburger.

[0113] EXAMPLES

[0114]

[0117] The following non-limiting examples illustrate the invention and do not limit its scope in any way, as many variations of the present invention are possible without departing from its spirit or scope. In the examples and throughout this specification, all percentages, parts and ratios are by weight unless indicated otherwise.

[0115]

[0118] Example 1

[0116]

[0119] Raw Materials:

[0117]

[0120] Three different sunflower protein sources, each processed differently, were used to obtain sunflower protein isolate.

[0121] Sunflower white flake (SF-WF) was obtained from a conventional industrial sunflower crushing line from Bunge. Sunflower seeds were partially dehulled, flaked, conditioned, hot pressed at 100°C to 110°C, and solvent extracted by hexane. The sample was taken postextraction but before the desolventization toasting / cooling step. Desolventization was performed under gentle conditions (room temperature, no heat treatment) to avoid denaturation of proteins.

[0118]

[0122] SunPro 46 white flake (SP46-WF) was also produced in a conventional industrial sunflower crushing line of Bunge. Sunflower seeds were partially dehulled, flaked, conditioned, hot pressed at 100°C to 110°C, and solvent extracted by hexane. The sample was taken post-extraction but before the desolventization toasting / cooling step. Desolventization was performed under gentle conditions (room temperature, no heat treatment) to avoid denaturation of proteins. Dry fractionation by milling and sieving further concentrated the protein content to about 46 % by weight in the protein rich fraction.

[0119]

[0123] Sunflower Protein Flour (SPF) was produced according to the following steps: dehulling the sunflower seeds to form dehulled sunflower kernels, having a maximum hull content of 0.05 wt.%; cold pre-pressing the dehulled sunflower kernels (Farmet process with the gap set a minimum size) at a maximum temperature of 60°C (e.g., 55°C) to form a pressed cake of the dehulled kernels; extracting oil from the pressed cake with an oil extraction solvent (e.g., hexane) by combining 1 kg sample with 3 L hexane in a glass reactor and performing seven extraction stages with 3 L of fresh hexane per stage to form an extracted pressed cake having an oil content around 60 wt.% on a dry basis and a protein content of 23 wt.% on a dry matter basis; and desolventizing the extracted pressed cake under gentle conditions (room temperature, no heat treatment) to form Sunflower Protein Flour (SPF). The SPF has a protein content of 58.6 wt.% on a dry matter basis; a protein dispersibility index (PDI) of 42.5; a moisture content of 8.7 wt.%; a fatty matter content of 1.3 wt.% on a dry matter basis; and a sugar content of less than 7.6 wt.%.

[0120]

[0124] Sunflower Protein Isolate Production Process:

[0121]

[0125] To produce sunflower protein isolate, a sunflower protein source (SF-WF, SP46-WF, or SPF) was mixed with water containing sodium sulfite (0.05 to 1.0 % w / w, or 0.004 to 0.079 mol / L) and heated up to 55 °C before adding the sunflower protein source. The solids-to-water ratio was 1 :9-1 : 10 w / w.

[0122]

[0126] Alkaline Extraction. A two-step alkaline extraction process was then employed to extract the protein from the protein source. The first extraction step was a mild process (pH 9.5, using 10 % aqueous NaOH solution) performed for 20 minutes at 55 °C to extract a majority of the proteins without causing side reactions. The resulting alkaline-solubilized protein slurry was then centrifuged to separate it into a solid, high-fiber fraction and a liquid, high-protein fraction.

[0123]

[0127] Second Alkaline Extraction. Next, the solid, high-fiber fraction was resuspended in water (1 :2 (w / w) of wet solids to water) containing sodium sulfite (up to 0.50 w / w%) and heated to 55 °C before suspending and subjecting to a second alkaline extraction. This second alkaline extraction step was conducted for 5 minutes at a higher pH of 11.0 (using 10% aqueous NaOH) and a temperature of 55 °C to maximize protein extraction yield while preserving protein quality. The second alkaline protein slurry was then centrifuged into a solid, high- fiber / low-protein fraction and a second liquid, high-protein fraction.

[0124]

[0128] Acid Precipitation. Following the alkaline extractions, the alkaline, liquid, high-protein fractions from both extractions were combined and their temperature was adjusted to 25-60 °C. The pH of the combined slurry was then lowered to 4.5 by adding a 10% HC1 solution. The mixture was mixed gently to promote the formation of large flocculants. This pH 4.5 slurry was centrifuged to separate it into a liquid albumin protein fraction and a solid globulin protein fraction.

[0125]

[0129] Globulin Protein Washing. The globulin protein solid fraction was then thoroughly mixed with wash water (1 :2 ratio of centrifuge solids to wash water) and then separated. This separated the mixture into a washed solid globulin protein fraction and a washed liquid albumin protein fraction.

[0126]

[0130] Albumin Protein Isolation. The washed solid globulin protein fraction was then resuspended in water to achieve a 12% dry matter content. This resuspended fraction was homogenized using a high shear homogenizer, and its pH was adjusted to 6.5. Finally, the resuspended globulin protein fraction was spray dried using a Biichi Mini Spay Dryer B-290. The inlet air temperature was 180 °C, the inlet protein slurry dry matter content ranged from about 10% to 12%, and the outlet air temperature was 80-85 °C. This step yielded the final sunflower protein isolate of globulin protein.

[0127]

[0131] A summary of the process parameters is provided in Table 1.

[0128]

[0132] Table 1 - Summary of the extraction process parameters

[0129]

[0130]

[0133] The protein yield, solids yield, and protein content on a dry matter basis (dm%) of the precipitated protein isolate (globulin protein) were determined. Protein content was determined according to ISO 5983-2 (Determination of nitrogen content and calculation of crude protein content, Block digestion and steam distillation method). The results are shown in Table 2.

[0131]

[0134] Table 2 - Protein contents of the raw materials and the precipitated protein isolates (globulin protein) and the protein yield and the solids yields respectively

[0132] Precipitated protein isolates (globulin protein)

[0133] Protein Solids Yield Protein Yield Protein

[0134] Raw material (dm%)a(%)b(%)c(dm%)d SF-WF 38,7 23,2 50,3 93,0

[0135] SP46-WF 52,9 26,6 48,8 92,1

[0136] SPF 58,2 31,7 54,3 93,9aExpressed as percentage of proteins in the raw materials of the isolation procedure measured and calculated by ISO 5983-2 Determination of nitrogen content and calculation of crude protein content, Block digestion and steam distillation method;bExpressed as percentage of solids respect to the amount present in the raw materials: weight (g) of solid product, produced from 100 g of raw material;cExpressed as percentage of proteins respect to the proteins present in the raw materials weight (g) of proteins of the product, produced from 100 g of proteins of the raw materials;dExpressed as percentage of proteins in the precipitated protein isolates (globulin protein), measured and calculated by ISO 5983-2 Determination of nitrogen content and calculation of crude protein content, Block digestion and steam distillation method)

[0137]

[0135] The protein content of the precipitated protein isolates (globulin protein) exceeded 90% in all cases. Notably, both the solids yield and protein yield were highest when using SPF as the raw material.

[0138]

[0136] Visually, the precipitated protein isolate produced from SPF appeared white, while those produced from SF-WF and SP46-WF appeared beige and light brownish, respectively. To further characterize color, analysis was performed using CIELAB color space, referred to as L*a*b*, as defined by the International Commission on Illumination. Measurements were conducted using a Hunter Labscan Calorimeter equipped with a Hunter Color Flex EZ (or equivalent) under D65 light with 10° observer response. Samples were milled to below 100 pm using a UDY Mill (or equivalent) and placed in a Fisher brand petri dish (stackable lid, polystyrene, Cat. # FB0875712) (or equivalent). The results are presented in Table 3.

[0139]

[0137] Table 3 - CIE L*a*b* color of the spray-dried precipitated globulin protein isolates prepared from different raw materials: SF-WF, SP46-WF and SPF

[0140]

[0138] In the CIELAB color space, L* represents lightness (black = 0, white = 100), a* represents green-red (red = + a*, green = - a*), and b* represents blue-yellow (yellow = + b*, blue = - b*).

[0141]

[0139] As indicated by the CIELAB results, the precipitated protein isolate (globulin protein) derived from SPF as the raw material exhibited the highest lightness value (L*), making it very desirable for use in food or feed applications.

[0142]

[0140] Example 2

[0143]

[0141] Sunflower protein isolates, as precipitated sunflower globulin protein and soluble sunflower albumin protein, were extracted and isolated from Sunflower Protein Flour (SPF). As in Example 1, Sunflower Protein Flour (SPF) was produced according to the following steps: dehulling the sunflower seed to form dehulled sunflower kernels; cold pre-pressing the dehulled sunflower kernels to form a pressed cake at a maximum temperature of 60°C; extracting oil from the pressed cake with an oil extraction solvent (e.g., hexane) to form an extracted pressed cake having an oil content around 60 wt.% on a dry basis; and desolventizing the extracted pressed cake to form Sunflower Protein Flour (SPF). The desolventisation step was performed under the same conditions as above. The SPF comprises globulin protein (11 S), albumin protein (2S), oil, polyphenols and fiber.

[0144]

[0142] Alkaline Extraction. 120 kg of SPF was suspended into 1080 kg of water (1 :9 solids- to-water weight ratio) and heated to 55 °C. Sodium sulfite (4.2 kg, equivalent to 0.35 % on a wet basis) was added to the slurry. The pH was adjusted to 9.5 using 10% NaOH (29.3 kg) and gently mixed for 20 minutes at 55 °C and 160 rpm. The slurry was then decanted using a Flottweg Z23 decanter (500 kg / h, 4000 g) to separate a solid, high-fiber fraction and a first liquid, high-protein fraction.

[0145]

[0143] Second Alkaline Extraction. The solid, high-fiber fraction was resuspended in water (1 :2 solids-to-water weight ratio) containing 0.15 w / w% sodium sulfite and heated up to 55 °C. The pH was adjusted to 11.0 and held for 5 minutes at 55 °C and 160 rpm. This slurry was decanted using the same Flottweg Z23 decanter to yield a solid, high-fiber / low-protein fraction and a second liquid, high-protein fraction.

[0146]

[0144] Acid Precipitation. Both liquid, high-protein fractions from the first and second extractions were immediately acidified to pH 4.5 using 10% HC1 under gentle agitation (80 rpm) at 55-60 °C. The acidified slurry was mixed gently for 60 minutes and separated using a Flottweg Z23 decanter (400 kg / hr, 3500 g) into a liquid albumin protein fraction and a solid globulin protein fraction.

[0147]

[0145] Globulin Protein Washing. The solid globulin protein fraction was resuspended in water (55-60 °C) at a 1 :2 solid-to-water ratio (w / w). This suspension was mixed for 5 minutes at 55- 60 °C and 80 rpm. A Flottweg Z23 decanter (400 kg / hr, 3500 g) was again used to separate a washed solid globulin protein fraction and a washed liquid albumin protein fraction.

[0148]

[0146] Albumin Protein Isolation. The liquid fractions of the precipitated slurry and the washing step (liquid albumin protein fraction and liquid albumin protein wash fraction) were combined and clarified by using a GEA Easy Scale disc stack centrifuge (g-force: 17,000 g, feed flow rate: 300 kg / hr, back pressure: 5 bar). The clarified liquid underwent membrane filtration using a SYNDER organic 3838 MWCO 5000 Da ultrafiltration membrane. Preconcentration took place in a Tangential filtration skid TIA 1000, followed by concentration and diafiltration in a Tangential filtration skid TIA 150 was used. Three diafiltration steps, with a feed pressure of 1 bar and maximum volumetric concentration factor (VCF), were applied to wash the concentrated albumin protein solution, removing polyphenols.

[0149]

[0147] Albumin Drying. The final retentate of the concentrated albumin protein was adjusted to 12% dry matter, homogenized, and its pH adjusted to 7.0 . This solution was heat-treated using an APV steam injection system at 130 °C or 140 °C and then spray dried using a Multistage dryer MSD 80 (inlet temperature: 180 °C, outlet temperature: 80-85 °C, bi-fluid nozzle pressure: 2 bar). This process yielded the sunflower albumin protein isolate.

[0150]

[0148] Globulin Protein Isolation. The separated heavy fraction from the clarification step (albumin protein isolation) was combined with the washed solid globulin protein fraction (from globulin protein washing step). This combined fraction slurry was homogenized using a high- shear mixer and its dry matter content adjusted to 12.0% by adding water. The pH of this suspension was adjusted to 7.0 and then heat-treated in an APV steam injection system for pasteurization and to examine the impact of heat treatment (at 130 °C or 140 °C) on the gelation and emulsification properties of the final product.

[0151]

[0149] Globulin Protein Drying. The globulin protein suspension was spray-dried under the same conditions as the albumin protein isolate (Multistage dryer MSD 80; inlet temperature: 180 °C, outlet temperature: 80-85 °C, bi-fluid nozzle pressure: 2 bar). This resulted in the sunflower globulin protein isolate.

[0152]

[0150] The characteristics of the obtained sunflower albumin protein isolates and sunflower globulin protein isolates are shown in Table 4.

[0151] Table 4 - Characteristics of the obtained sunflower albumin protein isolates and sunflower globulin protein isolates

[0153]

[0152] All sunflower protein isolates (both globulin protein isolates and albumin protein isolates) had a protein content of at least 90%. Notably, globulin protein isolates demonstrated high water holding capacity, particularly after heat treatment at 140°C, suggesting outstanding gelation properties desirable for use in texturizing plant-based meat or fish analogs. Albumin protein isolates exhibited high oil holding capacity, potentially advantageous for oil-rich products or formulations. The high emulsion capacity observed in both globulin and albumin protein isolates indicates their potential as stabilizers in oil-in-water emulsions, particularly in food applications.

[0154]

[0153] Color Analysis. Color analysis of the sunflower protein isolates (both globulin protein isolates and albumin protein isolates) was conducted using the CIELAB color space (L*a*b)* as defined by the International Commission on Illumination. Measurements were performed using a Hunter Labscan Calorimeter with a Hunter Color Flex EZ (or equivalent) under D65 light and a 10° observer. Samples were milled to below 100 pm using a UDY Mill (or equivalent) and placed in a Fisher brand petri dish (stackable lid, polystyrene, Cat. # FB0875712) (or equivalent) before measurement. The results are shown in Table 5.

[0154] Table 5 - CIELAB Color Values of Sunflower Protein Isolates

[0155]

[0155] In the CIELAB color space, L* represents lightness (black = 0, white = 100), a* represents green-red (red = + a*, green = - a*), and b* represents blue-yellow (yellow = + b*, blue = - b*).

[0156]

[0156] All sunflower protein isolates were predominantly whitish, showing minimal discoloration. No green or blue hues were observed.

[0157]

[0157] The listing or discussion of an apparently prior-published document in this specification should not necessarily be taken as an acknowledgement that the document is part of the state of the art or is common general knowledge.

[0158]

[0158] Preferences and options for a given aspect, embodiment, feature or parameter of the invention should, unless the context indicates otherwise, be regarded as having been disclosed in combination with any and all preferences and options for all other aspects, embodiments, features and parameters of the invention.

[0159]

[0159] As will be understood by one skilled in the art, for any and all purposes, particularly in terms of providing a written description, all ranges disclosed herein also encompass any and all possible subranges and combinations of subranges thereof. Any listed ranges can be easily recognized as sufficiently describing and enabling the same range being broken down into at least equal halves, thirds, quarters, fifths, tenths, etc. As will also be understood by one skilled in the art all language such as “up to”, “at least”, “greater than”, “less than,” and the like, include the number recited and refer to ranges which can be subsequently broken down into subranges as discussed above. Finally, as will be understood by one skilled in the art, a range includes each individual member, and each separate value is incorporated into the specification as if it were individually recited herein.

Claims

CLAIMS1. A process for obtaining sunflower protein isolate, wherein the process comprises the following steps:(1) dehulling the sunflower seed to form dehulled sunflower kernels wherein the sunflower kernels comprise oil, protein, fibers, sugars and polyphenols;(2) cold pre-pressing the dehulled sunflower kernels to form a pressed cake wherein the temperature of the dehulled kernels and pressed cake is 65°C or less;(3) processing the pressed cake by extracting oil therefrom with an oil extraction solvent to form an extracted pressed cake;(4) desolventizing the extracted pressed cake to form sunflower protein flour;(5) mixing the sunflower protein flour with water and a reducing agent to form a first suspension and adjusting the pH value of the first suspension to from 8.0 to 11.0;(6) separating the first suspension to form a first liquid fraction comprising sunflower protein and a first solid fraction comprising fiber;(7) mixing the first solid fraction comprising fiber with water and optionally a reducing agent to form a second suspension and adjusting the pH value of the second suspension to from 10.0 to 12.0;(8) separating the second suspension to form a second liquid fraction comprising sunflower protein and a second solid fraction comprising fiber; and(9) obtaining sunflower protein isolate by isolation and / or purification from the first liquid fraction, the second liquid fraction or the combination thereof.

2. The process according to claim 1, wherein the temperature of the dehulled kernels and pressed cake in step (2) is from 20°C to 65°C, preferably from 25°C to 65°C, more preferably from 35°C to 60°C and even more preferably from 40°C to 55°C.

3. The process according to claim 1 or 2, wherein the oil content of the pressed cake obtained in step (2) is 65 wt.% on a dry basis or less, preferably from 20 wt% to 65 wt.%, more preferably from 40 wt% to 65 wt.% and even more preferably from 40 wt.% to 50%.

4. The process according to any one of the preceding claims, wherein the protein dispersibility index (PDI) of the sunflower protein flour obtained in step (4) is at least 25%, preferablyfrom 30% to 90%, more preferably from 35% to 70% and even more preferably from 39% to 50%.

5. The process according to any one of the preceding claims, wherein the protein content of the sunflower protein flour obtained in step (4) is from 45 wt.% on a dry basis to 70 wt.% on a dry basis, preferably from 50 wt.% on a dry basis to 65 wt.% on a dry basis, more preferably from 52 wt.% on a dry basis to 63 wt.% and even more preferably from 55 wt.% on a dry basis to 60 wt.% on a dry basis.

6. The process according to any one of the preceding claims, wherein the oil extraction solvent in step (3) is hexane, ethanol, or a combination thereof, preferably the oil extraction solvent having a purity of at least 95 v / v%.

7. The process according to any one of the preceding claims, wherein the oil extraction step is an immersion extraction, preferably comprising at least two sequential extractions, more preferably at least four sequential extractions and even more preferably at least seven sequential extractions.

8. The process according to any one of the preceding claims,- wherein the reducing agent content in the first suspension of step (5) is from 0.001 mol / L to 0.100 mol / L; and / or- wherein the reducing agent content in the second suspension of step (7) is at most 0.040 mol / L.

9. The process according to any one of the preceding claims, wherein step (5) or step (7) is carried out at a temperature of from 25°C to 65°C, preferably from 35°C to 60°C, more preferably from 45°C to 60°C and even more preferably from 50°C to 60°C.

10. The process according to any one of the preceding claims,- wherein the weight ratio of the sunflower protein flour to water in the first suspension of step (5) is from 1 :5 to 1 : 15, preferably from 1 :6 to 1 : 14, more preferably from 1 :7 to 1 : 12 and even more preferably from 1 :8 to 1 : 11; and / or- wherein the weight ratio of the first solid fraction comprising fiber to water in the second suspension of step (7) is from 1 : 1 to 1 :5.

11. The process according to any one of the preceding claims,- wherein the first suspension of step (5) is held by the pH value of from 8.0 to 10.0 for from 5 minutes to 60 minutes, preferably for from 10 minutes to 30 minutes; and / or- wherein the second suspension of step (7) is held by the pH value of from 10.0 to 12.0 for from 1 minute to 60 minutes, preferably for from 1 minute to 10 minutes.

12. The process according to any one of the preceding claims for extracting sunflower globulin protein isolate or sunflower albumin protein isolate, wherein the step (9) of the process comprises:(a) adjusting the pH value of the first liquid fraction, the second liquid fraction or the combination thereof to from 3.0 to 6.0, preferably from 4.0 to 5.0 at a temperature of from 25°C to 65°C, preferably from 50°C to 60°C to form a globulin protein solid fraction and an albumin protein liquid fraction;(b) washing the globulin protein solid fraction at a pH value of from 3.0 to 6.0, preferably from 4.0 to 5.0 where the weight ratio of the globulin protein solid fraction to water is from 1 : 1 to 1 :5, preferably from 1 :1.5 to 1 :3;(c) separating a globulin protein washed solid fraction and an albumin protein wash liquid fraction; and(d) clarifying the albumin protein liquid fraction, the albumin protein wash liquid fraction or the combination thereof, for example by centrifuge to form a clarified globulin protein solid fraction and a clarified albumin protein liquid fraction.

13. The process according to claim 12 for extracting sunflower globulin protein isolate, wherein the step (9) of the process further comprises:(el) homogenizing the globulin protein washed solid fraction, the clarified globulin protein solid fraction or the combination thereof with water to form a globulin protein suspension with a dry matter content of from 10% to 20% by weight, preferably from 11% to 15% by weight;(fl) adjusting the pH value of the globulin protein suspension to from 4.5 to 8.0, preferably from 5.0 to 7.5;(gl) optionally, heat-treating the pH adjusted globulin protein suspension at a temperature of from 60°C to 160°C, preferably from 100°C to 150°C for from 5 seconds to 60 seconds; and(hl) obtaining the sunflower globulin protein isolate by drying the globulin protein suspension, such as by spray-draying.

14. The process according to claim 12 for extracting sunflower albumin protein isolate, wherein the step (9) of the process further comprises:(e2) filtrating the clarified albumin protein liquid fraction, for example by membrane filtration, preferably by a pH value of from 3.0 to 6.0, to form a filtrated albumin protein liquid fraction and an impurity fraction comprising polyphenols and sugars;(f2) homogenizing the filtrated albumin protein liquid fraction with water to form an albumin protein suspension with a dry matter content of from 10% to 20% by weight, preferably from 11% to 15% by weight;(g2) adjusting the pH value of the albumin protein suspension to from 4.5 to 8.0, preferably from 5.0 to 7.5;(h2) optionally, heat-treating the pH adjusted albumin protein suspension at a temperature of from 60°C to 160°C, preferably from 100°C to 150°C for from 5 seconds to 60 seconds; and(i2) obtaining the sunflower albumin protein isolate by drying the albumin protein suspension, such as by spray-draying.

15. A sunflower globulin protein isolate obtained by claim 13, having a protein content of at least 85% on a dry basis, preferably at least 88% on a dry basis, more preferably from 90% to 98% on a dry basis and even more preferably from 90% to 95% on a dry basis; and / or a protein dispersibility index (PDI) of at least 5, preferably from 10 to 70, more preferably from 15 to 60 and even more preferably from 20 to 55; and / or a water holding capacity, in gram per gram (g / g), of from 1 to 6, preferably from 1.5 to 5, more preferably from 2 to 4.5 and even more preferably from 2.5 to 4.0; and / or an oil holding capacity, in gram per gram (g / g), of from 0.5 to 3, preferably from 1.0 to 2.5, more preferably from 1.0 to 2.0 and even more preferably from 1.2 to 1.5; and / oran emulsion capacity, in gram of oil per gram of protein, of from 100 to 500, preferably from 120 to 450, more preferably from 150 to 400 and even more preferably from 170 to 380; and / or an L* value measure in the CIELAB color space of at least 71, preferably from 72 to 95, more preferably from 73 to 90 and even more preferably from 74 to 84; and / or an a* value measure in the CIELAB color space of from -2.0 to +4.5, preferably from -1.0 to +4.0, more preferably from -0.5 to +4.0 and even more preferably from 0.0 to +4.0; and / or a b* value measure in the CIELAB color space of from -2.0 to +15.0, preferably from -1.0 to +14.0, more preferably from -0.5 to +14.0 and even more preferably from 0.0 to +14.0.

16. A sunflower albumin protein isolate obtained by claim 14, having a protein content of at least 85% on a dry basis, preferably at least 88% on a dry basis, more preferably from 90% to 98% on a dry basis and even more preferably from 92% to 96% on a dry basis; and / or a protein dispersibility index (PDI) of at least 20, preferably from 30 to 85, more preferably from 40 to 80 and even more preferably from 50 to 78; and / or a water holding capacity, in gram per gram (g / g), of from 0 to 5, preferably from 0 to 4, more preferably from 0.1 to 2.0 and even more preferably from 0.2 to 0.5; and / or an oil holding capacity, in gram per gram (g / g), of from 0.5 to 8, preferably from 2 to 7, more preferably from 3 to 6 and even more preferably from 4 to 6; and / or an emulsion capacity, in gram of oil per gram of protein, of from 50 to 300, preferably from 80 to 250, more preferably from 100 to 230 and even more preferably from 150 to 210; and / or an L* value measure in the CIELAB color space of at least 70, preferably from 75 to 98, more preferably from 80 to 95 and even more preferably from 85 to 90; and / or an a* value measure in the CIELAB color space of from -2.0 to +3.0, preferably from -1.0 to +2.5, more preferably from -0.5 to +2.0 and even more preferably from 0.0 to +2.0; and / or a b* value measure in the CIELAB color space of from -2.0 to +15.0, preferably from -1.0 to +14.0, more preferably from -0.5 to +13.5 and even more preferably from 0.0 to +13.0.

7. Use of a sunflower globulin protein isolate according to claim 15 or a sunflower albumin protein isolate according to claim 16 in a food product, preferably in a confectionery product, a bakery product or a culinary product, more preferably in cake, ice-cream, whipped cream, cheese, plant-based meat, plant-based cheese, plant-based ice-cream or plant-based whipped cream and even more preferably in plant-based meat such as plantbased bacon, plant-based sausage or plant-based hamburger.

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