Fluid injection method to modify functional attributes of protein in direct expanded extrusion

Abstract

In certain embodiments, the present invention provides a method of producing an extruded food product comprising the steps of: (a) inserting a fluid component comprising a liquid ingredient and protein ingredient that forms a slurry into an extruder to form a hydrated dough, (b) subjecting the hydrated dough to controlled heat, shear, and pressure conditions in an extruder to form a modified dough, (c) extruding the modified dough to form an extruded food product. In certain embodiments, the present invention provides a method of producing a food ingredient comprising: (a) injecting a fluid component comprising a liquid ingredient and a protein ingredient that forms a slurry into an extruder, (b) subjecting the fluid component to controlled heat, shear, and pressure conditions to form a modified dough, (c) extruding the modified dough to form an extruded food ingredient. Also provided in certain embodiments are extruded food products and ingredients made by these methods.

Description

[0001] FLUID INJECTION METHOD TO MODIFY FUNCTIONAL ATTRIBUTES OF PROTEIN IN DIRECT EXPANDED EXTRUSION

[0002] CROSS-REFERENCE TO RELATED APPLICATIONS

[0003] This application claims priority to United States Provisional Application Number 63 / 457,024, filed April 4, 2023. The entire content of the application referenced above is hereby incorporated by reference herein.

[0004] BACKGROUND

[0005] Direct expanded extrusion (extrusion) is a process of creating puffy expanded snacks using heat and pressure. Breakfast cereals, crisps, snack curls, etc. are often made using this technology.

[0006] Traditionally, extrusion is done by first adding powders into a chamber where it is hydrated into a dough and conveyed through the chamber using one or two screws. The dough is then subjected to aggressive heat and pressure, and pushed out the exiting end, where it expands, puffing into a unique shape. See Figure 1. Chemically, this extrusion process can be complicated because changing properties of the dough (viscosity, wetness, heat stability, etc.) can dramatically change how the dough interacts with the heat and pressure. Because of this, some types of ingredients, such as proteins, are extremely difficult to use in an extruder.

[0007] Proteins tend to be difficult to use in an extruder for many reasons. Many proteins form gels when heated, which can clog up equipment. Also, it is often difficult to mix proteins with liquid in the chamber to form a consistent dough. Further, proteins tend to get desiccated hard shells when heated and dried, which prevents the product from becoming a desirable snack. Phase separation, off flavors, and browning are also common problems of heating protein doughs in an extrusion process, which can have a negative impact on these products.

[0008] Accordingly, improved fluid injection methods to modify functional attributes of protein in direct expanded extrusion is needed.

[0009] SUMMARY

[0010] In certain embodiments, the present invention provides a method of producing an extruded food product comprising the steps of (a) inserting a fluid component comprising a liquid ingredient and protein ingredient that forms a slurry into an extruder to form a hydrated dough, (b) subjecting the hydrated dough to controlled heat, shear, and pressure conditions in an extruder to form a modified dough, (c) extruding the modified dough to form an extruded food product. In certain embodiments, the present invention provides a method of producing a food ingredient comprising: (a) injecting a fluid component comprising a liquid ingredient and a protein ingredient that forms a slurry into an extruder, (b) subjecting the fluid component to controlled heat, shear, and pressure conditions to form a modified dough, (c) extruding the modified dough to form an extruded food ingredient.

[0011] In certain embodiments, the present invention provides an extruded food product produced by (a) inserting a fluid component comprising a liquid ingredient and protein ingredient that forms a slurry into an extruder to form a hydrated dough, (b) subjecting the hydrated dough to controlled heat, shear, and pressure conditions in an extruder to form a modified dough, (c) extruding the modified dough to form an extruded food product.

[0012] In certain embodiments, the present invention provides an extruded food product produced by (a) injecting a fluid component comprising a liquid ingredient and a protein ingredient that forms a slurry into an extruder, (b) subjecting the fluid component to controlled heat, shear, and pressure conditions to form a modified dough, (c) extruding the modified dough to form an extruded food ingredient.

[0013] BRIEF DESCRIPTION OF DRAWINGS

[0014] Figure 1. Simple schematic of traditional extrusion processing.

[0015] Figure 2. Exemplary process flow chart of the present novel fluid injection method.

[0016] DETAILED DESCRIPTION

[0017] The present inventors have developed novel methods to modify proteins to overcome many of the hurdles inherent in extruding proteins. Unlike previous extrusion methods that are performed using powdered protein ingredients, the newly-developed present methods are performed with fluid protein ingredients.

[0018] Using fluid protein is beneficial, both from functional and economical points of view. From a functional viewpoint, drying a protein will change its functional characteristics, so using protein as a fluid maintains beneficial functional characteristics. From an economic viewpoint, drying methods are expensive, labor intensive, and involve shipping, so using protein as a fluid will reduces costs.

[0019] The present technology provides methods to modify protein prior to introduction into direct expanded extrusion. This is done by hydrating and injecting product in fluid form rather than feeding in powder form. The implementation of fluid injection dramatically changes how the equipment is run, as well as changing the characteristics of puffed products. The present methods are not intuitive and changes how several aspects of processing are approached. The present methods overcome hurdles in direct expanded extrusion of protein. This technology enables novel incorporation of proteins in extrusion, the use of new proteins into extrusion, and the formation of novel products using protein.

[0020] In certain embodiments of the present technology, a protein ingredient is hydrated and modified, and then a fluid component containing the protein ingredient (e.g., modified protein, hydrated functional protein) is injected directly into the extruder. This fluid component can be custom modified depending on the characteristics desired in the resulting product. This allows one to overcome some of the hurdles of protein extrusion, as well as allowing the ability to utilize some proteins that may not have been usable otherwise. A schematic of one embodiment of a process flow of the present invention is provided in Figure 2. This newly developed process would not be obvious to one knowledgeable to the art of extrusion because many ingredients used in extrusion expand when subject to water, so the idea of adding water first to form the fluid component would prevent some of the early expansion of many direct expanded ingredients.

[0021] The present process also has to be tightly regulated or else too much water is incorporated into the product. An excess of water in the product prevents the product from expanding correctly. One of skill in the art would believe that a modified product that is a fluid would contain too much water to be a dough, such that the water present in the substance is tied up in a hydrated ingredient, and would not be as readily available to be absorbed by an ingredient, such as a starch. However, the present inventors have found that despite some potential objections, the technology can be used to inject a portion of the protein as a modified fluid (the “fluid component").

[0022] The implementation of fluid injection dramatically changes extrusion processes, and the characteristics of resulting puffed products. The present processes overcome hurdles in direct expanded extrusion of protein. This technology enables novel incorporation of proteins in extrusion, the use of new proteins into extrusion, and the formation of novel products using protein.

[0023] Many products used in extrusion processes benefit from hydrolysis. Hydrolyzing enzymes are commonly used to break down proteins molecules into smaller units, which have lower viscosity and higher heat stability. To-date, however, many vegan proteins are not sold as hydrolysates, or are not hydrolyzed in the way needed for extrusion. Using the present technology, it is possible to hydrolyze a heat labile and high viscosity protein (i.e., a protein considered unfit for extrusion) in order it to make it into a quality extruded product. Another difficulty encountered in traditional extrusion processes is that some proteins do not hydrate fast enough to be used in extrusion. Traditionally, these proteins needed to be hydrated for hours before being incorporated into an extruder as a fluid.

[0024] The present methods allows for the use of proteins that have never been dried (also called “fresh” proteins). Many dairy proteins experience dramatic changes after drying, such as emulsifying characteristics, gelling characteristics, and binding properties. Using the present process, fresh proteins (i.e., proteins that have never been dried) can be used in an extrusion process.

[0025] Many extruders require the use of a “preconditioner” to partially wet down and heat up powders before they are injected into the extruder. As used herein, “preconditioning” is defined as a process by which powder is subject to hydration and heat, commonly at 1-25% moisture. Preconditioning facilitates hydration and allows formation of a dough. Preconditioning, however, is time and energy intensive, can require specialized equipment and can be expensive. With the present technology, it is possible to reduce or eliminate the need for a preconditioner.

[0026] Some proteins are not pasteurized before packaging. These proteins are not considered “ready to eat” (RTE) and must be heat treated prior to consumption. Although heat treatment is performed in extrusion, it is difficult to validate for legal purposes. The present methods allow a customer to pasteurize an ingredient that does not meet RTE requirements, without irradiating or using another invasive sterilizing technique.

[0027] Fluid Injection Method for Protein

[0028] In certain embodiments, the present invention provides a method of producing an extruded food product comprising the steps of: (a) inserting a fluid component comprising a liquid ingredient and protein ingredient that forms a slurry into an extruder to form a hydrated dough, (b) subjecting the hydrated dough to controlled heat, shear, and pressure conditions in an extruder to form a modified dough, (c) extruding the modified dough to form an extruded food product.

[0029] In certain embodiments, the present invention provides a method of producing a food ingredient comprising: (a) injecting a fluid component comprising a liquid ingredient and a protein ingredient that forms a slurry into an extruder, (b) subjecting the fluid component to controlled heat, shear, and pressure conditions to form a modified dough, (c) extruding the modified dough to form an extruded food ingredient. Liquid Ingredient

[0030] In certain aspects, the liquid ingredient is, but is not limited to, an aqueous or oil based fluid. In certain aspects, the liquid ingredient is water. The liquid ingredient could also be an emulsion or suspension of aqueous and oil or hydrocolloid based components. In certain aspects, the fluid component is preconditioned prior to injection. In certain aspects, more than one fluid component is injected into the extruder to form the hydrated dough. In certain aspects, the fluid component is modified prior to injection into the extruder.

[0031] Proteins

[0032] In certain aspects, proteins are, but are not limited to, milk protein concentrates, milk protein isolates, non-fat dry milk solids, whey protein concentrate, whey protein isolate, sweet whey products, micellar casein products, acid caseins, sodium caseinates, calcium caseinates, other caseinates, whey protein phospholipid concentrate (or ProCream®), milk mineral extracts containing protein, modified variants on these ingredients (including hydrlysates), other milk solids and their derivates, whether fresh or powdered in origin. Additionally, proteins can be a pea protein concentrate (yellow pea, chick pea, etc.), pea protein isolate (yellow pea, chick pea, etc.), pea protein flours, faba protein concentrate, other lentil or legume proteins, canola protein concentrate, canola protein isolate, chia protein, flax protein (golden or brown), soy protein concentrate, soy protein isolate, pumpkin protein, mung bean protein, potato protein, rice protein, or other vegetable proteins, whether they are concentrates, isolates, or flours. The protein can also be bovine proteins, collagen proteins, egg (albumin) proteins or derivates, synthetic proteins, algae proteins, cell mass proteins, or insect proteins (cricket, etc.), whether in concentrate or isolate form.

[0033] In certain aspects, the protein solids are fresh. As used herein, the term “fresh” when referring to protein solids means that the protein solids have never been dried.

[0034] In certain aspects, the protein ingredient is heat labile. As used herein the term “labile” means susceptible to alteration or destruction. As used herein a “heat labile protein” is one that can be changed or destroyed at high temperatures; i.e., its form, structure, and / or function is changed or destroyed at high temperatures. The opposite of labile in this context is “stable.” As used herein, the proteins are considered labile at temperatures above 60'5C.

[0035] Fluid Component

[0036] In certain aspects, the fluid component comprises a liquid ingredient and a protein ingredient that forms a slurry. In certain aspects, the fluid component comprises about 1-40% protein ingredient by weight and about 60-99% moisture (i.e., liquid ingredient). In certain aspects, the fluid component is 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, 21%, 22%, 23%, 24%, 25%, 26%, 27%, 28%, 29%, 30%, 31%, 32%, 33%, 34%, 35%, 36%, 37%, 38%, 39%, 40% protein solids and 99.9%, 99.8%, 99.7%, 99.6%, 99.5%, 99.4%, 99.3%, 99.2%, 99.1%, 99%, 98%, 97%, 96%, 95%, 94%, 93%, 92%, 91%, 90%, 89%, 88%, 87%, 86%, 85%, 84%, 83%, 82%, 81%, 80%, 79%, 78%, 77%, 76%, or 75%, 74%, 73%, 72%, 71%, 70%, 69%, 68%, 67%, 66%, 65%, 64%, 63%, 62%, 61%, 60% moisture (i.e., liquid ingredient), respectively. In certain aspects, percent of total protein solids or solids of final extrudate the fluid component comprises about 5-10% protein solids and about 90-95% liquid ingredient. In certain aspects, the fluid component comprises about 15-25% protein solids and about 85-75% fluid. In certain embodiments, the total solids for plant proteins are, but are not limited to, 15- 20% solids, whereas dairy proteins are, but are not limited to, 10-25% solids.

[0037] In certain aspects, the protein ingredient is hydrated.

[0038] In certain aspects, the fluid component is hydrolyzed prior to injection.

[0039] In certain aspects, the fluid component is cultured prior to injection or following injection.

[0040] In certain aspects, the fluid component is fermented prior to injection or following injection.

[0041] Other Ingredients

[0042] In certain embodiments, one or more additional ingredients are combined with or into the fluid component, wherein the fluid component comprises a liquid ingredient and a protein ingredient.

[0043] In certain embodiments, one or more additional ingredients are inserted or injected as an additional ingredient(s) into the extrusion chamber.

[0044] In certain embodiments, the one or more additional ingredients are a protein, fiber, starch, flour, oil, sweetener, vitamin, hydrocoloid, colorant and / or processing aid. A processing aid is defined as an ingredient used to facilitate or improve processing characteristics. In certain aspects, processing aid is present at concentrations under 2%. In certain aspects, a processing aid is present at 0%, 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1.0%, 1.1%, 1.2%, 1.3%, 1.4%, 1.5%, 1.6%, 1.7%, 1.8%, 1.9% or 2.0% w / w.

[0045] In certain embodiments, the one or more additional ingredients are cultured prior to injection or following injection. In certain embodiments, wherein the one or more additional ingredients are fermented prior to combination with the fluid component or prior to injection or following injection into the extrusion chamber.

[0046] In certain embodiments, the one or more additional ingredients are not preconditioned prior to combination with the fluid component or prior to injection.

[0047] In certain embodiments, the one or more additional ingredients are preconditioned prior to combination with the fluid component or prior to injection.

[0048] In certain embodiments, the fluid component and the one or more additional ingredients are combined prior to combination with the fluid component or prior to injection into the extruder.

[0049] In certain embodiments, the fluid component and the one or more additional ingredients are injected separately into the extruder and combined in the extruder.

[0050] Examples of other ingredients could include proteins with unique functional characteristics (including but not limited to whey, caseinates, gluten, soy, etc), fibers with unique characteristics (methylcellulose, lentil fiber, soluble tapioca fibers, corn fiber, etc), Starches with unique characteristics (rice starch, lentil starch, tapioca starch, etc), flours with unique characteristics (com flour, wheat flours, fine particle size flours, etc), oils with unique characteristics (canola oil, vegetable oils, MCT oil, etc), and processing aids (acidulants, calcium carbonate, preservatives, phosphates, enzymes, desiccants, agents, alkalizing agents, etc.).

[0051] Hydrated Dough

[0052] In certain aspects, a hydrated dough is generated that contains about 40-90% protein ingredient and about 10-60% liquid ingredient. In certain embodiments, the hydrated dough contains about 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80% 85%, or 90% protein.

[0053] Extrusion Conditions

[0054] Conditions such as heat, pressure, and mechanical shear change depending on application, protein source, other ingredients, etc. These conditions would be known to one skilled in the art. As an example, the protein fortified dough is heated to 120°C, subject to a screw profile with some mechanical resistance, and extruded with a die pressure of 400psi. Conditions vary dramatically between product characteristics and raw ingredients used, but would be known to one skilled in the art. Extruded Food Product and Ingredients

[0055] The present technology allows for higher levels of protein inclusion than would otherwise be possible in many applications. In certain aspects, the present invention is an extruded food product or ingredient produced by the methods described herein. In certain aspects, the extruded food product comprises 40-90% protein. In certain aspects, the extruded food product comprises 40%, 41%, 42%, 43%, 44%, 45%, 46%, 47%, 48%, 49%, 50%, 51%, 52%, 53%, 54%, 55%, 56%, 57%, 58%, 59%, 60%, 61%, 62%, 63%, 64%, 65%, 66%, 67%, 68%, 69%, 70%, 71%, 72%, 73%, 74%, 75%, 76%, 77%, 78%, 79%, 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, or 90% protein.

[0056] In certain aspects the extruded food product comprises 5-95 grams of protein per 100 grams of product. In certain aspects, the extruded food product comprises 5, 6, 7, 8, 9, 10, 11,

[0057] 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37,

[0058] 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63,

[0059] 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89,

[0060] 90, 91, 92, 93, 94 or 95 grams of protein per 100 grams of product.

[0061] The invention will now be illustrated by the following non-limiting Examples.

[0062] EXAMPLE 1

[0063] The following is an example that compares the difference between the traditionally used standard high protein extrusion without fluid injection (see Figure 1) with the present novel fluid injection method (see Figure 2). There is no difference in the composition of the crisp (Table 1). The only difference in this example is that the crisps are made using two different processing methods. The two processing methods yielded crisps with completely different characteristics, as indicated in Table 2.

[0064] Table 1. Crisp Composition Table 2. Changes in Processing Conditions:

[0065] *Fluid injection with no other treatments applied. Shows the water absorption and changes in other characteristics.

[0066] EXAMPLE 2

[0067] In one example, pea protein concentrate was hydrated to 25% solids and hydrolyzed the material to an 18% degree of hydrolysis (DH) over the course of 3 hours. That material was then injected into an extruder and mixed with a blend of pea protein, starch, and calcium carbonate. When extruding under similar processing conditions, the product was dramatically wetter and more noodle like (indicative of product where moisture needs to be removed can still be removed). However, once moisture was removed to account for the increased moisture retention, the extrudate was significantly more cohesive, more easily shaped, better expanded, and softer. The product could also be taken to much lower moisture levels where the product became dramatically softer and less glassy. This hydrolyzed slurry was also dried and added directly into the hopper, the product was slightly more expanded than the control, but nowhere near as soft, dry, or expanded as the fluid injected treatment.

[0068] EXAMPLE 3

[0069] In another example, a Milk Protein Isolate (MPI) was solubilized over the course of 24 hours at 20% solids. This MPI was then injected into an extruder making protein crisp containing MPI, rice starch, and calcium carbonate. The final blend targeted a 40% protein target. The untreated crisp was unexpanded, dense, and glassy in texture. However, by allowing the casein to fully solubilize in the MPI, the product expanded much better than the control developing a much softer texture. This product also had a finer cell structure which allowed for easier drying.

[0070] EXAMPLE 4

[0071] In another example, pea protein concentrate was hydrated and an alkalizing agent was used (NaOH) in fluid form to increase the total pH. This was then used to make a high protein content application (55% protein), by combining with pea protein concentrate, tapioca starch, and calcium carbonate. In this application, the change in pH allowed for better solubilization of the powdered product, as well as encouraging more pasting properties of the entire mixture. Allowing for a dough that easily set, had smoother edges, and shows promise in using in more complicated shapes.

[0072] Although the foregoing specification and examples fully disclose and enable the present invention, they are not intended to limit the scope of the invention, which is defined by the claims appended hereto.

[0073] All publications, patents and patent applications are incorporated herein by reference. While in the foregoing specification this invention has been described in relation to certain embodiments thereof, and many details have been set forth for purposes of illustration, it will be apparent to those skilled in the art that the invention is susceptible to additional embodiments and that certain of the details described herein may be varied considerably without departing from the basic principles of the invention.

[0074] The use of the terms “a” and “an” and “the” and similar referents in the context of describing the invention are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. The terms “comprising,” “having,” “including,” and “containing” are to be construed as open-ended terms (z.e., meaning “including, but not limited to”) unless otherwise noted. Recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein, and each separate value is incorporated into the specification as if it were individually recited herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g., “such as”) provided herein, is intended merely to better illuminate the invention and does not pose a limitation on the scope of the invention unless otherwise claimed. No language in the specification should be construed as indicating any non-claimed element as essential to the practice of the invention.

[0075] Embodiments of this invention are described herein, including the best mode known to the inventors for carrying out the invention. Variations of those embodiments may become apparent to those of ordinary skill in the art upon reading the foregoing description. The inventors expect skilled artisans to employ such variations as appropriate, and the inventors intend for the invention to be practiced otherwise than as specifically described herein. Accordingly, this invention includes all modifications and equivalents of the subject matter recited in the claims appended hereto as permitted by applicable law. Moreover, any combination of the above-described elements in all possible variations thereof is encompassed by the invention unless otherwise indicated herein or otherwise clearly contradicted by context.

Claims

What is claimed is:

1. A method of producing an extruded food product comprising the steps of:(a) inserting a fluid component comprising a liquid ingredient and protein ingredient that forms a slurry into an extruder to form a hydrated dough,(b) subjecting the hydrated dough to controlled heat, shear, and pressure conditions in an extruder to form a modified dough,(c) extruding the modified dough to form an extruded food product.

2. A method of producing a food ingredient comprising:(a) injecting a fluid component comprising a liquid ingredient and a protein ingredient that forms a slurry into an extruder,(b) subjecting the fluid component to controlled heat, shear, and pressure conditions to form a modified dough,(c) extruding the modified dough to form an extruded food ingredient.

3. The method of claim 1 or 2, wherein the fluid component comprises one or more protein ingredients.

4. The method of any one of claims 1-3, wherein the fluid component further comprises a fiber, starch, flour, oil, processing aid, sweetener and / or colorant.

5. The method of any one of claims 1-4, wherein the fluid component is fermented prior to injection or following injection.

6. The method of any one of claims 1-5, wherein fluid component is preconditioned prior to injection.

7. The method of any one of claims 1-6, wherein the fluid component is modified prior to injection into the extruder.

8. The method of any one of claims 1-7, wherein step (a) further comprises inserting a fluid into the extrusion chamber.

9. The method of claim 8, wherein the fluid is an aqueous based fluid, an oil based fluid, an emulsion or suspension of aqueous and oil or hydrocolloid based components.

10. The method of claim 9, wherein the fluid is water.

11. The method of any one of claims 1-10, wherein step (a) further comprises inserting an additional ingredient into the extrusion chamber.

12. The method of claim 6d, wherein the additional ingredient is a fiber, starch, flour, oil, processing aid, sweetener and / or colorant.

13. The method of any one of claims 1-12, wherein the protein ingredient is fresh.

14. The method of any one of claims 1-12, wherein the protein ingredient is hydrated.

15. The method of any one of claims 1-14, wherein the fluid component comprises about0.1%-40% protein ingredient by weight and about 60%-99.9% liquid ingredient.

16. The method of any one of claims 1-15, wherein the liquid ingredient is an aqueous fluid, an oil, a hydrocolloid, an emulsion or suspension of aqueous fluid and oil, or an emulsion or suspension of aqueous fluid and hydrocolloid.

17. The method of any one of claims 1-16, wherein the modified dough comprises between 35-80% protein ingredient.

18. An extruded food product produced by the method of any one of claims 1-17.

19. The extruded food product of claim 18, wherein the extruded food product comprises 5-95 grams of protein per 100 grams of product.

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