WO2018125920A1

WO2018125920A1 - Method of manufacturing a nutritional powder with in situ protein hydrolysis

Info

Publication number: WO2018125920A1
Application number: PCT/US2017/068539
Authority: WO
Inventors: Timothy LAPLANTE; Son Pham; Nalini Patel; Gul Konuklar
Original assignee: Abbott Laboratories
Current assignee: Abbott Laboratories
Priority date: 2016-12-30
Filing date: 2017-12-27
Publication date: 2018-07-05
Anticipated expiration: 2019-06-30

Abstract

A method of manufacturing a nutritional powder with in situ protein hydrolysis using extrusion technology is provided. The method includes adding an intact protein source, a protease component, a fat component, and water to an extruder to form a slurry. The slurry is emulsified within the extruder to form an emulsion. The emulsion has a total protein content of 5% to 35% based on the weight of the solids of the emulsion and at least a portion of the protein is hydrolyzed within the extruder to achieve a degree of hydrolysis of 5% to 30%. The emulsion is then dried and milled to form a nutritional powder.

Description

METHOD OF MANUFACTURING A NUTRITIONAL POWDER

WITH IN SITU PROTEIN HYDROLYSIS

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to and the benefit of U.S. Provisional Patent Application No. 62/440,499, filed December 30, 2016, the entire content of which is incorporated by reference herein.

FIELD

[0002] The present disclosure relates to a method of preparing nutritional powders. More particularly, the present disclosure relates to a method of preparing a nutritional powder with in situ protein hydrolysis using extrusion technology.

BACKGROUND

[0003] Protein hydrolysates are used in various nutritional products and supplements. Certain nutritional products such as infant formulas and muscle enhancing supplements include protein hydrolysates because the protein hydrolysates are partially pre-digested and more easily absorbed as compared to intact protein. However, as an ingredient used in nutritional products, protein hydrolysates are often much more expensive than intact proteins because of the additional manufacturing steps, reagents {e.g., enzymes), and time involved in producing the protein hydrolysates.

SUMMARY

[0004] Disclosed herein is a method of preparing a nutritional powder with in situ protein hydrolysis using extrusion technology. To illustrate various aspects of the present disclosure, several exemplary embodiments of the method are provided herein.

[0005] In one exemplary embodiment, a method of preparing a nutritional powder is provided. The method includes adding an intact protein source, a protease component, a fat component, and water to an extruder to form a slurry. The slurry is emulsified within the extruder to form an emulsion. The emulsion has a total protein content of 5% to 35% based on the weight of the solids of the emulsion, and at least a portion of the protein is hydrolyzed within the extruder to achieve a degree of hydrolysis of 5% to 30%. The emulsion is then dried and milled to form a nutritional powder.

[0006] In certain exemplary embodiments, the intact protein source and the protease component are added to the extruder in amounts so that a weight ratio of active protease to protein is from 0.2: 100 to 2: 100. In certain exemplary embodiments, a pH adjuster is added to the extruder to maintain a pH of the slurry at from 5 to 9. In certain exemplary embodiments, the slurry is heated to a temperature of from 35 °C to 75 °C. In certain exemplary embodiments, the emulsion is heated to a temperature of from 80 °C to 105 °C to promote inactivation of the protease component and to pasteurize the emulsion.

[0007] In certain exemplary embodiments, the emulsion comprises from 30% to 90% by weight solids. In certain exemplary embodiments, at least one of a carbohydrate component, vitamins, and minerals are added to the extruder.

[0008] In one exemplary embodiment, a method of preparing a nutritional powder is provided. The method includes adding an intact protein source into one or more inlets of an extruder, adding a protease component into one or more inlets of the extruder, adding water into one or more inlets of the extruder, and adding a fat component into one or more inlets of the extruder to form a slurry within the extruder. A pH adjuster is added into one or more inlets of the extruder to maintain the slurry at a pH of from 5 to 9. The slurry is emulsified within the extruder to form an emulsion. The emulsion has a total protein content of 5% to 35% based on the weight of the solids of the emulsion, and at least a portion of the protein is hydrolyzed within the extruder to achieve a degree of hydrolysis of 5% to 30%. The emulsion is then dried and milled to form a nutritional powder.

BRIEF DESCRIPTION OF THE DRAWINGS

[0009] FIG. 1 is a schematic diagram of an embodiment of a method of preparing a nutritional powder with in situ protein hydrolysis as described herein.

[0010] FIG. 2 is a schematic diagram of an embodiment of a method of preparing a nutritional powder with in situ protein hydrolysis as described herein. DETAILED DESCRIPTION

[0011] Disclosed herein are methods of preparing a nutritional powder with in situ protein hydrolysis using extrusion technology. While the present disclosure describes certain embodiments of the methods in detail, the present disclosure is to be considered exemplary and is not intended to be limited to the disclosed embodiments.

[0012] The terminology as set forth herein is for description of the embodiments only and should not be construed as limiting the disclosure as a whole. All references to singular characteristics or limitations of the present disclosure shall include the corresponding plural characteristic or limitation, and vice versa, unless otherwise specified or clearly implied to the contrary by the context in which the reference is made. Unless otherwise specified, "a," "an," "the," and "at least one" are used interchangeably. Furthermore, as used in the description and the appended claims, the singular forms "a," "an," and "the" are inclusive of their plural forms, unless the context clearly indicates otherwise.

[0013] The methods of preparing a nutritional powder as described in the present disclosure can comprise, consist of, or consist essentially of the essential elements of the disclosure as described herein, as well as any additional or optional element described herein or which is otherwise useful in extrusion related processes.

[0014] All percentages, parts, and ratios as used herein are by weight of the total formulation, unless otherwise specified. All such weights as they pertain to listed ingredients are based on the active level and, therefore, do not include solvents or by-products that may be included in commercially available materials, unless otherwise specified.

[0015] All ranges and parameters, including but not limited to percentages, parts, and ratios, disclosed herein are understood to encompass any and all sub-ranges assumed and subsumed therein, and every number between the endpoints. For example, a stated range of "1 to 10" should be considered to include any and all sub-ranges beginning with a minimum value of 1 or more and ending with a maximum value of 10 or less {e.g., 1 to 6.1, or 2.3 to 9.4), and to each integer (1, 2, 3, 4, 5, 6, 7, 8, 9, and 10) contained within the range. [0016] Any combination of method or process steps as used herein may be performed in any order, unless otherwise specified or clearly implied to the contrary by the context in which the referenced combination is made.

[0017] The term "intact protein source" as used herein, unless otherwise specified, refers to protein or a source of protein that has not been intentionally processed or treated in a manner intended to break peptide bonds. In other words, "intact protein source" refers to protein or a source of protein which is non-hydrolyzed and thus has not been subjected to an intentional hydrolysis treatment.

[0018] The term "active protease" as used herein, unless otherwise specified, refers to the portion of the protease component that exhibits protease activity. For example, a protease component in liquid form may only contain from about 9% to about 17% active protease by weight of the protease component, with the remainder of the protease component comprising solvent, preservatives, stabilizers, and the like.

[0019] The phrase "inactivation of the protease component" as used herein, unless otherwise specified, refers to a method step in which the protease component is rendered inactive, meaning that the protease component will no longer catalyze the hydrolysis reaction of the intact protein. In certain embodiments, the inactivation of the protease component is accomplished through the application of heat.

[0020] The term "pH adjuster" as used herein, unless otherwise specified, refers to a component that can change the pH of a mixture, or a component that when added to a mixture can resist a change to the pH. Exemplary pH adjusters include acids, bases, buffers, and combinations thereof.

[0021] The exemplary embodiments of the method of preparing a nutritional powder described herein utilize an extruder. Any suitable extruder that includes a high shear element or the like to emulsify the contents of the extruder may be used in accordance with the embodiments of the method of the present disclosure. For example, in certain exemplary embodiments, the extruder may be a single screw extruder, multi screw extruder, ring screw extruder, planetary gear extruder, and the like. [0022] In certain exemplary embodiments, the method of preparing a nutritional powder uses a co-rotating, twin screw extruder. Generally, twin screw extruders comprise a barrel having one or more inlets for adding ingredients, two screws, and a die or other outlet. The extruder screws are positioned inside of the barrel and may comprise a wide variety of functional elements in addition to a high shear element including, but not limited to, mixing elements, conveying elements, reverse elements, kneading elements, disc elements, or any combination of the foregoing in any interchangeable order. The barrel of the extruder may comprise a number of segments that are bolted, clamped, or otherwise joined together. The barrel or barrel segments may be jacketed to permit indirect, controlled heating or cooling of the material being processed within the extruder. In addition, the barrel or barrel segments may include one or more inlets for adding ingredients into the extruder. The extruder also includes one or more outlets (e.g., a die) to allow the material within the extruder to flow out of the extruder.

[0023] The use of an extruder to prepare the nutritional powder provides a number of benefits. For example, an extruder can mix together and emulsify the various components that comprise the nutritional powder at a high solids level (i.e., from 30% to 90% by weight solids), which reduces the amount of water required and thereby reduces costs associated with drying. Based on the ability of the extruder to handle a high solids level, throughput is increased within the extruder as compared to conventional processes for preparing a nutritional powder (e.g., preparing a slurry/emulsion and spray drying the slurry/emulsion). In addition, the extruder allows for increased automation, which enables greater process control. Furthermore, the extruder can reduce the microbial load of the nutritional powder due to the heat and shear generated within the extruder.

[0024] The exemplary embodiments of the method of preparing a nutritional powder described herein include in situ protein hydrolysis within the extruder so that the nutritional powder comprises hydrolyzed protein. It has been found that hydrolyzing an intact protein source with a protease component proceeds more efficiently (i.e., requires less protease) when the intact protein source is emulsified with a fat component and water in an extruder. Without wishing to be bound by theory, it is believed that the emulsion matrix and the high shear rate that can be achieved in an extruder promotes a faster rate of reaction due to an increased rate of diffusion of the protease component, which catalyzes hydrolysis of the intact protein source. Accordingly, the emulsifying step that occurs within the extruder promotes efficient hydrolysis of the intact protein source by spatial location of the proteins (on the outer surface of the fat) and is an important aspect of the exemplary methods disclosed herein.

[0025] Moreover, the exemplary embodiments of the method of preparing a nutritional powder with in situ protein hydrolysis have advantages over conventional methods of preparing nutritional powders that include hydrolyzed protein. For example, protein hydrolysate ingredients are much more expensive than commodity intact protein ingredients. The higher cost of protein hydrolysate ingredients is typically associated with the additional manufacturing steps, reagents {e.g., enzymes), and time involved in producing the protein hydrolysate ingredients. The exemplary embodiments of the methods described herein offset the higher costs associated with protein hydrolysates by using an intact protein source and streamlining the process of manufacturing the nutritional powder by using an extruder, which eliminates the additional manufacturing steps and the additional time that would otherwise go into preparing a protein hydrolysate ingredient.

[0026] In one exemplary embodiment, a method of preparing a nutritional powder comprises adding an intact protein source, a protease component, a fat component, and water to an extruder to form a slurry. The slurry is emulsified within the extruder to form an emulsion. The emulsion has a total protein content of 5% to 35% based on the weight of the solids of the emulsion. The intact protein source added to the extruder is hydrolyzed in situ such that the protein of the emulsion has a degree of hydrolysis of 5% to 30%. After exiting the extruder, the emulsion is dried and milled to form a nutritional powder.

[0027] In certain embodiments, the intact protein source added to the extruder is in powder form. The intact protein source in powder form may be added to the extruder by a variety of techniques including, but not limited to, gravity feeding from a hopper, pumping from a storage tank, and the like. In some embodiments, the intact protein source added to the extruder is in the form of an aqueous protein suspension. For example, the intact protein source may be mixed with water and the resulting aqueous protein suspension may be pumped into the extruder from a storage tank or other vessel. In certain embodiments, the aqueous protein suspension may be subjected to a heat treatment, a filtration process, such as a microfiltration process or an ultrafiltration process, or both a heat treatment and a filtration process prior to being added to the extruder.

[0028] In certain embodiments, the intact protein source, whether in powder form or aqueous suspension form, is added into one or more inlets of the extruder. The term "inlet" as used herein refers to an opening on the extruder through which material can be introduced into the extruder. An inlet of the extruder may be positioned anywhere along the length of the extruder. In certain embodiments, the intact protein source is added to the extruder through an inlet positioned within the first quarter of the length of the extruder. In certain embodiments, the extruder is a multi- barrel extruder and the intact protein source is added to the multi-barrel extruder through an inlet positioned on the first barrel of the multi-barrel extruder.

[0029] A wide variety of proteins or protein sources may be used as the intact protein source in the exemplary methods described herein. Exemplary proteins or protein sources suitable for use as the intact protein source in the exemplary methods disclosed herein include, but are not limited to, whey protein concentrate, whey protein isolate, casein, sodium caseinate, calcium caseinate, potassium caseinate, milk protein concentrate, milk protein isolate, non-fat dry milk, soy protein concentrate, soy protein isolate, pea protein concentrate, pea protein isolate, rice protein concentrate, rice protein isolate, potato protein concentrate, potato protein isolate, algal protein concentrate, algal protein isolate, corn protein concentrate, corn protein isolate, wheat protein concentrate, wheat protein isolate, oat protein concentrate, oat protein isolate, canola protein concentrate, canola protein isolate, sunflower protein concentrate, sunflower protein isolate, soy flour, peanut flour, and combinations thereof. In certain exemplary embodiments, the intact protein source comprises whey protein, such as a whey protein concentrate or a whey protein isolate.

[0030] To catalyze the hydrolysis reaction of the intact protein source, a protease component is added to the extruder. Generally, proteases are commercially available in liquid form or powder form. In certain embodiments, the protease component added to the extruder is in liquid form and may be added to the extruder, for example, by pumping the protease component into the extruder from a storage tank or other vessel. In certain embodiments, the protease component added to the extruder is in powder or granular form. The protease component in powder form may be added to the extruder by a variety of techniques including, but not limited to, gravity feeding from a hopper, pumping from a storage tank, and the like.

[0031] In certain embodiments, the protease component, whether in liquid or powder form, is added into one or more inlets of the extruder. In certain embodiments, the protease component is added to the extruder through an inlet positioned within the first half of the length of the extruder. In certain embodiments, the protease component is added to the extruder through an inlet positioned within the first quarter of the length of the extruder. It is also contemplated that a liquid protease component and a powder protease component may be added to the extruder through one or more inlets of the extruder either separately or together.

[0032] A wide variety of proteases may be used as the protease component in the exemplary methods described herein. Proteases may be classified by the source organism, the active pH range, the peptide bond specificity, and so forth. For example, a protease may be derived from certain bacteria or fungi; exhibit greater activity at an acidic pH, a neutral pH, or an alkaline pH; and may function as an endopeptidase, an exopeptidase, an amino acid specific protease, or combinations thereof. Any protease suitable for use in the food industry may be used as the protease component in the exemplary methods described herein. In certain embodiments, the protease component comprises a protease derived from Bacillus sp., such as Bacillus subtilis or Bacillus licheniformis. An exemplary commercially available protease derived from Bacillus sp. is Alcalase 2.4L from Novozyme A/S (Bagsvaerd, Denmark). In certain embodiments, the protease component comprises a protease derived from Aspergillus oryzae. An exemplary commercially available protease derived from Aspergillus oryzae is Flavourzyme 1000L from Novozyme A/S (Bagsvaerd, Denmark). Other proteases from Novozyme A/S (Bagsvaerd, Denmark) such as Neutrase 0.8L, a neutral endo-protease derived from Bacillus amyloliquefaciens, and Protamex, a neutral endo-protease derived from Bacillus sp., may also be used in the exemplary methods disclosed herein. In certain embodiments, the protease component comprises a mixture of proteases, for example a mixture of a protease derived from Bacillus licheniformis and a protease derived from Aspergillus oryzae. In certain other embodiments, different protease components may be added to the extruder through one or more inlets of the extruder either separately or together. [0033] As briefly mentioned above, a fat component is also added to the extruder. The fat component may be a liquid or a solid at room temperature (e.g., 20 °C to 25 °C), but when the fat component is added to the extruder it is in liquid form. The fat component may be added to the extruder by a variety of techniques including, but not limited to, gravity feeding from a hopper, pumping from a storage tank, and the like. In certain embodiments, the fat component is an oil that is added to the extruder, for example, by pumping the oil into the extruder from a storage tank or other vessel.

[0034] In certain embodiments, the fat component in liquid form is added into one or more inlets of the extruder. In certain embodiments, the fat component is added to the extruder through an inlet positioned within the first half of the length of the extruder. In certain embodiments, the fat component is added to the extruder through an inlet positioned within the second quarter of the length of the extruder. In certain embodiments, the fat component is added into an inlet of the extruder that is positioned downstream of the inlets into which the intact protein source and protease component are added.

[0035] A wide variety of fats or fat sources may be used as the fat component in the exemplary methods described herein. Exemplary fats or fat sources suitable for use as a fat component in the exemplary methods disclosed herein include, but are not limited to: high oleic safflower oil; soy oil; coconut oil; high oleic sunflower oil; safflower oil; sunflower oil; corn oil; palm oil; palm kernel oil; canola oil; olive oil; milk fat including butter; any animal fat or fraction thereof; fish or crustacean oils containing docosahexaenoic acid (DHA), eicosapentaenoic acid (EPA), or both; phospholipids from fish or crustacean containing DHA, EPA, or both; concentrates of DHA, EPA, or both, from marine, vegetable, or fungal sources; arachidonic acid (ARA) concentrate from fungal or other sources; alpha-linolenic acid concentrate (ALA); flax seed oil; borage oil or any other source of gamma linolenic acid (GLA); phospholipids and fractions thereof, including soy lecithin and egg lecithin, both partially hydrolyzed and unhydrolyzed; monoglycerides, diglycerides, or both; diacetyl tartaric acid ester of mono- and diglycerides (DATEM); and combinations thereof. The fat component may include any individual source of fat or combination of the various sources of fat listed above. [0036] Water is another component that is added to the extruder in the exemplary methods described herein. The water may be added into one or more inlets of the extruder. The water hydrates the intact protein source (when in powder form) and acts as a reactant and a solvent to facilitate the hydrolysis of the intact protein source. The water may also be used to control the solids content of the emulsion that is formed within the extruder. In certain embodiments, the water is added to the extruder through an inlet positioned within the first half of the length of the extruder. In certain embodiments, the water is added to the extruder through an inlet positioned within the first quarter of the length of the extruder. The water may be added to the extruder, for example, by pumping the water from a storage tank or other vessel.

[0037] In certain embodiments, the protease component is mixed with the water and the protease component-water mixture is added to the extruder. In certain embodiments, the protease component-water mixture is preheated before being added to the extruder. In certain embodiments, the protease component- water mixture is preheated to a temperature of from 30 °C to 90 °C, including from 35 °C to 80 °C, from 40 °C to 70 °C, from 50 °C to 60 °C, and also including 55 °C.

[0038] To facilitate pH control of the material within the extruder, in certain embodiments of the method disclosed herein, a pH adjuster is added to the extruder. The pH of the material within the extruder is a parameter that can affect the hydrolysis of the intact protein source since the protease component will have an optimal pH range for facilitating catalysis of the hydrolysis reaction. As the intact protein source is hydrolyzed within the extruder, the pH of the slurry and/or the emulsion within the extruder may change to a pH that is outside of the optimal pH range for the protease component. Accordingly, in certain embodiments of the methods disclosed herein, a pH adjuster is added into one or more inlets of the extruder to maintain the pH of the slurry and/or the emulsion within the optimal pH range of the protease component. In certain embodiments, a pH adjuster is added to the extruder via one or more inlets of the extruder to maintain a pH of the slurry and/or the emulsion within the extruder at from 5 to 9. In certain embodiments, the pH adjuster is added to the extruder through an inlet positioned within the first three-quarters of the length of the extruder. In certain embodiments, the pH adjuster is added to the extruder through an inlet positioned within the first half of the length of the extruder. In certain embodiments, the pH adjuster is added to the extruder through an inlet positioned within the first quarter of the length of the extruder. In certain embodiments, the pH adjuster is added to the extruder through an inlet positioned within the last quarter of the length of the extruder. In certain embodiments, the pH adjuster is added to the extruder in at least two separate inlets of the extruder. For example, in one embodiment, a first pH adjuster is added to the extruder through an inlet positioned within the first quarter of the length of the extruder, and a second pH adjuster, which may be the same or different than the first pH adjuster, is added to the extruder through an inlet positioned within the second half of the length of the extruder.

[0039] The pH adjuster may be in liquid form or powder form, and may be added to the extruder, for example, by pumping the pH adjuster, when in liquid form, from a storage tank or other vessel, or by gravity feeding the pH adjuster, when in powder form, from a hopper or other powder storage means. The pH adjuster added to the extruder may be an acid, a base, a buffer, and combinations thereof. Any food grade acid, base, buffer, and combinations thereof may be used in the exemplary methods disclosed herein. For example, in certain embodiments, a potassium hydroxide (KOH) solution or concentrate may be added to the extruder to raise the pH of the slurry and/or the emulsion to be within the optimal pH range of the protease component. In other embodiments, a hydrochloric acid (HQ) solution may be added to the extruder to lower the pH of the slurry and/or the emulsion to be within the optimal pH range of the protease component. To achieve the optimal pH range of the protease component, the addition of the pH adjuster may be calibrated or controlled with a pH sensing system (e.g., pH-stat) that is in contact with the material within the extruder.

[0040] In certain embodiments, at least one of a carbohydrate component, vitamins, and minerals are added to the extruder. Each of the carbohydrate component, vitamins, and minerals may be added to the extruder in a liquid form or a powder form. These components may be added to the extruder by a variety of techniques including, but not limited to, gravity feeding from a hopper, pumping from a storage tank, and the like. In certain embodiments, the carbohydrate component is in a powder form that is added to the extruder, for example, by gravity feeding the carbohydrate component from a hopper into the extruder.

[0041] In certain embodiments, the carbohydrate component, vitamins, and minerals, whether in liquid form or powder form, are added into one or more inlets of the extruder. In certain embodiments, the carbohydrate component is added to the extruder through an inlet positioned within the last half of the length of the extruder. In certain embodiments, the carbohydrate component is added to the extruder through an inlet positioned within the final quarter of the length of the extruder. In certain embodiments, the carbohydrate component is added into an inlet of the extruder that is positioned downstream of the inlets into which the intact protein source, protease component, water, and fat component are added. In certain embodiments, the carbohydrate component, vitamins, and minerals are in powder form and are added into the extruder via the same inlet. In certain embodiments, fat soluble vitamins (e.g., vitamin A, vitamin D, vitamin E) may be added to the extruder along with the fat component.

[0042] The carbohydrate or source of carbohydrate suitable for use as a carbohydrate component in the exemplary methods described herein may be simple, complex, or variations or combinations thereof. Generally, the carbohydrate component may include any carbohydrate or carbohydrate source that is suitable for use in nutritional powders and is otherwise compatible with any other selected ingredients or features in the nutritional powder.

[0043] Non-limiting examples of carbohydrates (or sources thereof) suitable for use as a carbohydrate component in the exemplary methods disclosed herein include, but are not limited to, polydextrose; maltodextrin; hydrolyzed or modified starch or cornstarch; glucose polymers; corn syrup; corn syrup solids; rice-derived carbohydrate; sucrose; glucose; fructose; lactose; honey; sugar alcohols (e.g., maltitol, erythritol, sorbitol); isomaltulose; sucromalt; pullulan; potato starch; and other slowly-digested carbohydrates; dietary fibers including, but not limited to, fructooligosaccharides (FOS), galactooligosaccharides (GOS), oat fiber, soy fiber, gum arabic, sodium carboxymethylcellulose, methylcellulose, guar gum, gellan gum, locust bean gum, konjac flour, hydroxypropyl methylcellulose, tragacanth gum, karaya gum, gum acacia, chitosan, arabinoglactins, glucomannan, xanthan gum, alginate, pectin, low methoxy pectin, high methoxy pectin, cereal beta-glucans (e.g., oat beta-glucan, barley beta-glucan), carrageenan and psyllium, digestion resistant maltodextrin (e.g., Fibersol™, a digestion-resistant maltodextrin including soluble dietary fiber); soluble and insoluble fibers derived from fruits or vegetables; other resistant starches; and combinations thereof. The carbohydrate component may include any individual source of carbohydrate or combination of the various sources of carbohydrate listed above. [0044] The vitamins and minerals used in the exemplary methods described herein may generally include those vitamins and minerals that are suitable for including in a nutritional powder. Non-limiting examples of vitamins or related nutrients suitable for use in the exemplary methods described herein include vitamin A, vitamin D, vitamin E, vitamin K, thiamine, riboflavin, pyridoxine, vitamin B12, carotenoids (e.g., beta-carotene, lutein), niacin, folic acid, pantothenic acid, biotin, vitamin C, choline, inositol, salts and derivatives thereof, and combinations thereof. Non-limiting examples of minerals suitable for use in the exemplary methods described herein include calcium, phosphorus, magnesium, iron, zinc, manganese, copper, sodium, potassium, molybdenum, chromium, chloride, and combinations thereof.

[0045] After the intact protein source, the protease component, the fat component, and the water are added to the extruder and a slurry is formed therefrom, the slurry is emulsified within the extruder to form an emulsion. As the intact protein source and the protease component come into contact within the extruder, the protease component catalyzes the hydrolysis reaction of the intact protein source such that the emulsion formed within the extruder comprises hydrolyzed protein having a degree of hydrolysis of 5% to 30%. In certain embodiments, the emulsion formed within the extruder comprises hydrolyzed protein having a degree of hydrolysis of from 8% to 30%, including from 10% to 28%, from 13% to 25%, from 15% to 25%, from 15% to 20%), and also including from 5% to 15%>. In certain embodiments, the emulsion formed within the extruder comprises hydrolyzed protein having a degree of hydrolysis of 10%> to 15%>.

[0046] The degree of hydrolysis is the extent to which peptide bonds are broken by the hydrolysis reaction. The degree of hydrolysis may be determined by quantifying the amino nitrogen to total nitrogen ratio (AN/TN) of the protein. The amino nitrogen component may be quantified by USP titration methods for determining amino nitrogen content, while the total nitrogen component may be determined by the Tecator® Kjeldahl method. These analytical methods are well known.

[0047] Another parameter that can affect the hydrolysis of the intact protein source within the extruder is the weight ratio of active protease to protein. As previously mentioned, the amount of active protease in a particular protease component can vary depending on whether the protease component is in liquid form or in powder or other solid form. Similarly, the amount of protein in a particular intact protein source can vary widely. For example, the amount of protein in a particular whey protein concentrate powder may contain about 30% protein by weight of the powder, with the remainder of the powder comprising carbohydrates, fats, minerals, and the like. In certain embodiments of the methods disclosed herein, the intact protein source and the protease component are added to the extruder in amounts so that a weight ratio of active protease to protein is from 0.2: 100 to 2: 100, including from 0.2: 100 to 1.8: 100, from 0.2: 100 to 1.5: 100, from 0.2: 100 to 1.25: 100, from 0.2: 100 to 0.9: 100, and also including from 0.2: 100 to 0.5: 100. The surprisingly low weight ratios of active protease to protein when used in the exemplary methods disclosed herein have been found to result in an emulsion and resulting nutritional powder that contains hydrolyzed protein having a degree of hydrolysis of 5% to 30%. As mentioned above, it is believed that the emulsifying step carried out within the extruder promotes a faster hydrolysis reaction and that the fat component and other components work in synergy with the intact protein source and the protease component to make the hydrolysis reaction more efficient.

[0048] In accordance with the exemplary methods disclosed herein, the emulsion formed within the extruder has a total protein content of from 5% to 35% based on the weight of solids of the emulsion, including from 10% to 30%, from 10% to 25%, from 10% to 20%, from 15% to 35%), and also including a total protein content of from 15% to 25% based on the weight of solids of the emulsion. In certain embodiments, the emulsion formed within the extruder has a total fat content of from 0.5% to 40% based on the weight of solids of the emulsion, including from 15% to 40%, from 20% to 35%, from 20% to 30%, from 25% to 35%, from 25% to 30%, from 1% to 15%, from 1% to 10%, from 1% to 5%, from 5% to 20%, from 10% to 20%, and also including a total fat content of from 15% to 20% based on the weight of solids of the emulsion. In certain embodiments, the emulsion formed within the extruder has a total carbohydrate content of from 40% to 80% based on the weight of solids of the emulsion, including from 45% to 75%, from 45% to 70%, from 50% to 70%, from 50% to 65%, from 50% to 60%, from 60% to 80%), from 65% to 75%, and also including a total carbohydrate content of from 65% to 70% based on the weight solids of the emulsion.

[0049] In certain embodiments, the emulsion comprises from 30% to 90% by weight solids, including from 30% to 80%, from 30% to 70%, from 30% to 60%, from 30% to 55%, from 35% to 90%, from 40% to 90%, from 45% to 90%, from 50% to 90%, from 60% to 90%, from 70% to 90%), or from 80% to 90% by weight solids. In general, the emulsion formed within and exiting the extruder is a paste-like mixture.

[0050] The total protein content of the emulsion formed within and exiting the extruder will typically depend on the amount of protein contained in the intact protein source as well as the amount of other components used to form the emulsion. For example, a whey protein concentrate powder used as the intact protein source may comprise at least 30% protein by weight of the powder, or a soy protein isolate powder used as the intact protein source may comprise at least 80%) protein by weight of the powder. In certain embodiments, the intact protein source used in the method comprises whey protein concentrate, and the emulsion has a total protein content of from 5% to 35% based on the weight of solids of the emulsion, including from 10% to 30%, from 10%) to 25%, from 10% to 20%, from 15% to 35%, and also including a total protein content of from 15% to 25% based on the weight of solids of the emulsion.

[0051] The processing of the material within the extruder may be carried out at various temperatures. The temperature of the material within the extruder is yet another parameter that can affect the hydrolysis of the intact protein source since the protease component will have an optimal temperature range for facilitating catalysis of the hydrolysis reaction. In certain embodiments, the methods disclosed herein comprise controlling the temperature of the material within the extruder. For example, in certain embodiments, the methods disclosed herein comprise heating the slurry and/or the emulsion to a temperature of from 35 °C to 75 °C, including from 40 °C to 75 °C, from 45 °C to 70 °C, from 50 °C to 65 °C, and also including from 50 °C to 60 °C. In certain embodiments, the methods disclosed herein comprise cooling the slurry and/or the emulsion to a temperature of from 35 °C to 75 °C, including from 40 °C to 75 °C, from 45 °C to 70 °C, from 50 °C to 65 °C, and also including from 50 °C to 60 °C. In certain other embodiments, the methods disclosed herein comprise heating and cooling the slurry and/or the emulsion within the extruder to maintain a temperature of from 35 °C to 75 °C, including from 40 °C to 75 °C, from 45 °C to 70 °C, from 50 °C to 65 °C, and also including from 50 °C to 60 °C.

[0052] As previously mentioned, the barrel or barrel segments of the extruder may be jacketed to permit indirect, controlled heating (e.g., by steam) or cooling (e.g., by cooling water) of the contents within the extruder. By way of example only, a first barrel of the extruder may be configured to maintain a temperature of 25 °C, a second barrel of the extruder may be configured to maintain a temperature of 60 °C, a third barrel of the extruder may be configured to maintain a temperature of 70 °C, and so forth.

[0053] In certain embodiments of the methods disclosed herein, the protease component in the emulsion is inactivated within the extruder. Inactivation of the protease component may be accomplished by heating the emulsion to a temperature that will denature the protease component. Furthermore, adjusting the pH toward the end of the extruder (e.g., within the last quarter of the length of the extruder) may also increase the efficiency of the protease inactivation by heat. For example, if an acidic pH is not suitable for a particular protease component, then lowering the pH may allow lower temperatures to inactivate the protease component. In certain embodiments, the exemplary methods disclosed herein further comprise heating the emulsion to a temperature of from 80 °C to 105 °C, including from 80 °C to 100 °C, from 85 °C to 95 °C, from 85 °C to 90 °C, and also including from 95 °C to 100 °C to promote inactivation of the protease component. In certain embodiments, the final quarter length of the extruder is configured to control the temperature of the emulsion at from 80 °C to 105 °C, including from 80 °C to 100 °C, from 85 °C to 95 °C, from 85 °C to 90 °C, and also including from 95 °C to 100 °C to promote inactivation of the protease component. In certain embodiments, the emulsion is heated to a temperature of from 80 °C to 105 °C, including from 80 °C to 100 °C, from 85 °C to 95 °C, from 85 °C to 90 °C, and also including from 95 °C to 100 °C for a time period of 30 seconds to 10 minutes, including from 1 minute to 8 minutes, from 1 minute to 6 minutes, from 1 minute to 5 minutes, from 2 minutes to 4 minutes, and also including from 5 minutes to 10 minutes to promote inactivation of the protease component.

[0054] In certain embodiments of the methods disclosed herein, the protease component in the emulsion is inactivated outside of the extruder. In certain embodiments, the exemplary methods disclosed herein further comprise heating the emulsion after it has exited the extruder to a temperature of from 80 °C to 105 °C, including from 80 °C to 100 °C, from 85 °C to 95 °C, from 85 °C to 90 °C, and also including from 95 °C to 100 °C for a time period of 30 seconds to 10 minutes, including from 1 minute to 8 minutes, from 1 minute to 6 minutes, from 1 minute to 5 minutes, from 2 minutes to 4 minutes, and also including from 5 minutes to 10 minutes to promote inactivation of the protease component. In certain embodiments of the methods disclosed here, the emulsion exits the extruder and enters a hold tube in which the emulsion is heated to a temperature of from 80 °C to 105 °C, including from 80 °C to 100 °C, from 85 °C to 95 °C, from 85 °C to 90 °C, and also including from 95 °C to 100 °C for a time period of 30 seconds to 10 minutes, including from 1 minute to 8 minutes, from 1 minute to 6 minutes, from 1 minute to 5 minutes, from 2 minutes to 4 minutes, and also including from 5 minutes to 10 minutes to promote inactivation of the protease component.

[0055] After the slurry is emulsified as described herein to form an emulsion, the emulsion exits the extruder, or a hold tube in certain embodiments, and is dried. In certain embodiments, the emulsion exiting the extruder may be cut into various sizes. The emulsion may be extruded as a cake, or may optionally be extruded through a die, which may reduce the amount of shear to which the emulsion is exposed. The shear applied at any time during the manufacturing process, and suitable during the emulsification step, may be continuous shear or non-continuous shear.

[0056] Numerous conventional drying means are suitable for drying the emulsion to a desired water content. For example, the emulsion may be dried using a vacuum belt dryer, a continuous microwave dryer, or a vacuum drum dryer. Other drying processes, including infrared drying or spray drying may also be used in some embodiments to produce a suitably dry emulsion for further processing into a nutritional powder. In certain embodiments, the emulsion exiting the extruder is dried at a temperature of from 80 °C to 180 °C, including from 85 °C to 170 °C, from 90 °C to 160 °C, from 95 °C to 150 °C, from 100 °C to 140 °C, and also including from 105 °C to 130 °C. Drying techniques such as microwave drying, radiant drying, and conduction drying may be used.

[0057] An exemplary vacuum belt dryer is the Merk Vacuum belt dryer which includes an infrared component and a direct contact heater. Where used, the amount of drying time will typically depend on the amount of water added to the extruder. For example, about 1.0 kg/hr to about 1.6 kg/hr of water may require about 5 minutes to about 45 minutes of drying time, such as about 25 minutes. The vacuum pressure may be about 20 millibar (mbar) to about 50 mbar, such as about 30 mbar. The vacuum drying temperature may be from 100 °C to 170 °C. [0058] After the emulsion is dried, the dried emulsion is milled or otherwise ground to form a nutritional powder. In certain embodiments, high impact milling is used to mill the dried emulsion to form the nutritional powder. Alternatively, other conventional milling or grinding processes may be used to form the nutritional powder from the dried emulsion. The milling or grinding step may be carried out so as to impart a desired particle size to the nutritional powder. In certain embodiments, the nutritional powder may have a particle size of from 50 microns to 750 microns, including from 100 microns to 500 microns, and also including from 100 microns to 250 microns. In certain embodiments, the nutritional powder may be milled or otherwise ground so that the nutritional powder has a particle size distribution such that at least 1 wt% of the nutritional powder comprises particles that are 500 microns and larger, at least 1 wt% of the nutritional powder comprises particles that are 100 microns and smaller, and at least 90 wt% of the nutritional powder comprises particles that are between 100 microns and 500 microns.

[0059] The processing of the various components added to the extruder to prepare the nutritional powder according to the exemplary methods disclosed herein may be carried out at various residence times. In certain embodiments of the methods disclosed herein, the components added to the extruder are processed within the extruder for 2 minutes to 60 minutes, including from 2 minutes to 45 minutes, from 5 minutes to about 30 minutes, from 5 minutes to 25 minutes, from 10 minutes to 20 minutes, from 5 minutes to about 20 minutes, or from 2 minutes to 10 minutes to prepare the emulsion that is subsequently dried and milled to form the nutritional powder. Furthermore, the processing of the various components within the extruder may be carried out as a continuous process or as a batch process.

[0060] In another exemplary embodiment, a method of preparing a nutritional powder comprises adding an intact protein source into one or more inlets of an extruder, adding a protease component into one or more inlets of the extruder, adding water into one or more inlets of the extruder, and adding a fat component into one or more inlets of the extruder to form a slurry within the extruder. A pH adjuster is added into one or more inlets of the extruder for maintaining the slurry at a pH of 5 to 9. The slurry is emulsified within the extruder to form an emulsion that has a total protein content of 5% to 35% based on the weight of the solids of the emulsion. The intact protein source added to the extruder is hydrolyzed in situ such that the protein of the emulsion has a degree of hydrolysis of 5% to 30%. After exiting the extruder, the emulsion is dried and milled to form a nutritional powder. Any one or more of the intact protein sources, the protease components, the fat components, the pH adjusters, and additional components (e.g., carbohydrate component, vitamins, and minerals) previously described may also be used in this exemplary method. Any of the previously described processing conditions or parameters (e.g., pH, temperature, weight ratio of active protease to protein, solids content, residence time) apply equally to this exemplary method.

[0061] Referring now to FIG. 1, an exemplary embodiment of a method of preparing a nutritional powder with in situ protein hydrolysis using extrusion technology is shown in schematic form. In this exemplary embodiment, an intact protein source in powder form (whey protein concentrate) (WPC) and a protease component- water mixture preheated to 55 °C (Water + Protease 55 °C) are added to the first barrel of a fourteen barrel twin-screw extruder. The first barrel is maintained at room temperature (e.g., 20 °C to 25 °C). A 1 N KOH solution (KOH) is used as a pH adjuster and is added to the second barrel of the extruder. The WPC, water, protease component, and KOH are mixed within the extruder and conveyed to subsequent barrels of the extruder. During the initial mixing and conveying of the material in the extruder, the hydrolysis of the WPC begins. A fat component (Oil) is added to the fifth barrel of the extruder. To sufficiently mix the Oil with the WPC, water, protease component, and KOH, the extruder includes one or more high shear elements to emulsify the material within the extruder to form an emulsion. As the emulsion is further mixed and conveyed within the extruder, a carbohydrate component, vitamins, and minerals (Powder 2) are added to the eleventh barrel of the extruder and mixed together with the emulsion in the extruder. The temperatures of the second barrel through the eleventh barrel of the extruder are maintained at from 35 °C to 75 °C to heat the material within the extruder. The temperatures of the twelfth barrel through the fourteenth barrel are maintained at from 80 °C to 105 °C to promote inactivation of the protease component. The emulsion exiting the extruder comprises hydrolyzed protein and is subsequently dried in a dryer. The dried emulsion is then milled or otherwise ground in a mill or similar equipment to produce a nutritional powder.

[0062] With reference now to FIG. 2, an additional exemplary embodiment of a method of preparing a nutritional powder with in situ protein hydrolysis using extrusion technology is shown in schematic form. In this exemplary embodiment, an intact protein source in powder form (whey protein concentrate) (WPC) and a protease component-water mixture preheated to 55 °C (Water + Protease 55 °C) are added to the first barrel of a fourteen barrel twin-screw extruder. The first barrel is maintained at room temperature (e.g., 20 °C to 25 °C). A first 1 N KOH solution (1st KOH) is added to the second barrel of the extruder to adjust the pH of the material within the extruder to promote hydrolysis of the WPC as the material within the extruder is mixed and conveyed. A fat component (Oil) is added to the fifth barrel of the extruder. To sufficiently mix the Oil with the WPC, water, protease component, and KOH, the extruder includes one or more high shear elements to emulsify the material within the extruder to form an emulsion. As the emulsion is further mixed and conveyed within the extruder, a carbohydrate component, vitamins, and minerals (Powder 2) are added to the eleventh barrel of the extruder and mixed together with the emulsion in the extruder. In addition, a 45% w/v KOH solution (2nd KOH) added to the eleventh barrel of the extruder and mixed together with the emulsion to adjust the pH of the emulsion. The temperatures of the second barrel through the eleventh barrel of the extruder are maintained at from 35 °C to 75 °C to heat the material within the extruder. The temperatures of the twelfth barrel through the fourteenth barrel are maintained at from 80 °C to 105 °C to promote inactivation of the protease component. The emulsion exiting the extruder comprises hydrolyzed protein and is subsequently dried in a dryer. The dried emulsion is then milled or otherwise ground in a mill or similar equipment to produce a nutritional powder.

[0063] In one exemplary embodiment, a nutritional powder prepared according to any one of the exemplary methods described herein is provided. The nutritional powders prepared according to the methods described herein comprise protein having a degree of hydrolysis of from 5% to 30%.

EXAMPLES

[0064] The following examples illustrates exemplary embodiments and features of the methods of preparing a nutritional powder with in situ protein hydrolysis using extrusion technology as disclosed herein. The example is given solely for the purpose of illustration and is not to be construed as limiting the present disclosure, as many variations thereof are possible without departing from the spirit and scope of the disclosure. Example 1

[0065] Example 1 illustrates an exemplary method of preparing a nutritional powder with in situ protein hydrolysis using extrusion technology as disclosed herein. The processing equipment used to prepare the protein hydrolysate in this example included a 14-barrel twin-screw extruder coupled with two powder feeders and three liquid feeders. At the startup of each trial, the intact protein source in powder form was added gradually to avoid powder build up in the extruder. The extruder was operated at 500 revolutions per minute (RPM) in each trial.

[0066] A total of 5 trials were conducted using the equipment set up illustrated schematically in FIG. 1. In each trial, a whey protein concentrate (WPC) powder containing about 6% moisture by weight of the powder and about 76% protein by weight of the solids content of the powder was used as the intact protein source. The protease component used in each trial was Alcalase 2.4L (Novozyme A/S, Bagsvaerd, Denmark), which is a liquid product that contains about 9% active protease by weight of the liquid. The protease component was mixed with water and preheated to 55 °C (Water + Protease 55 °C) prior to being added to the extruder. A IN KOH solution (KOH) was also used in each trial. The fat component (Oil) added to the extruder included high oleic safflower oil, soy oil, coconut oil, arachidonic acid (ARA) oil (45% ARA), docosahexaenoic acid (DHA) oil (45% DHA), mixed carotenoids (e.g., beta-carotene, lutein, lycopene), vitamin A palmitate, vitamin A, vitamin D, vitamin E, vitamin K, and ascorbyl palmitate.

[0067] In each trial, the WPC powder and a protease component-water mixture were added to the first barrel of the extruder to hydrate the WPC. The first barrel was maintained at room temperature (e.g., 20 °C to 25 °C). The KOH was used as a pH adjuster to raise the pH of the material within the extruder and was added to the second barrel of the extruder. The WPC, water, protease component, and KOH were mixed within the extruder and conveyed to subsequent barrels of the extruder. During the initial mixing and conveying of the material within the extruder, the hydrolysis of the WPC began. The Oil was added to the fifth barrel of the extruder. To sufficiently mix the Oil with the WPC, water, protease component, and KOH, the extruder includes one or more high shear elements to emulsify the material within the extruder to form an emulsion. In trials 2-4, as the emulsion is further mixed and conveyed within the extruder, a carbohydrate component, vitamins, and minerals (Powder 2) were added to the eleventh barrel of the extruder and mixed together with the emulsion in the extruder. The temperatures of the second barrel through the eleventh barrel of the extruder were maintained at approximately 55 °C to heat the material within the extruder. The temperatures of the twelfth barrel through the fourteenth barrel were maintained at approximately 98 °C to promote inactivation of the protease component. Samples of the emulsion exiting the extruder were collected and cooled on ice for further analysis.

[0068] The feed rates for the materials added to the extruder in trials 1-5 are listed below in Table 1. In addition, the protease concentration, the approximate weight ratio of active protease to protein, the final pH of the emulsion, and the degree of hydrolysis (DH) of the hydrolyzed protein in the emulsion are shown in Table 1.

TABLE 1

[0069] The protease concentration is based on the amount of protease component and the amount of protein being fed into the extruder. For example, in trial 1, the feed rate of the protease component being added to the extruder was about 0.59 lb/hr and the feed rate of the WPC was about 4.095 lb/hr. However, the solids content of the WPC is about 94% and about 76%) by weight of the solids content of the WPC is protein, so the amount of protein fed into the extruder was about 2.93 lb/hr. Thus, dividing the protease feed rate (0.59 lb/hr) by the protein feed rate (2.93 lb/hr) gives a protease concentration of about 20%>.

[0070] The active protease to protein ratio is similar to the protease concentration, but considers only the active protease being fed into the extruder. As mentioned above, Alcalase 2.4L contains about 9%> active protease by weight. Accordingly, the weight ratio of active protease to protein can be determined by multiplying the protease concentration by the weight percentage of active protease. In trial 1, for example, multiplying the protease concentration (20%) by the weight percentage of active protease (9%) gives a weight ratio of active protease to protein of 1.8: 100.

[0071] As seen in Table 1, the emulsions that were produced contained hydrolyzed protein having a DH ranging from about 5% to about 11% using a protease concentration of about 20%. The reaction pH in trials 2-4 was lower than the reaction pH in trials 1 and 5 due to the addition of Powder 2. The reduction in reaction pH also led to the protein having a lower DH, particularly in trials 3 and 4. In trials 1-5, the total solids content of the emulsion exiting the extruder was from 30%) to 90%, and the protein content was from 5% to 35% based on the weight of total solids of the emulsion.

Example 2

[0072] Example 2 illustrates an exemplary method of preparing a nutritional powder with in situ protein hydrolysis using extrusion technology as disclosed herein. The processing equipment used to prepare the protein hydrolysate in this example included a 14-barrel twin-screw extruder coupled with two powder feeders and three liquid feeders. At the startup of each trial, the intact protein source in powder form was added gradually to avoid powder build up in the extruder. The extruder was operated at 500 revolutions per minute (RPM) in each trial except for trial 19, where the extruder was operated at 800 RPM.

[0073] A total of 32 trials were conducted using the equipment set up illustrated schematically in FIG. 2. In each trial, a whey protein concentrate (WPC) powder containing about 6% moisture by weight of the powder and about 76% protein by weight of the solids content of the powder was used as the intact protein source. The protease component used in each trial was Alcalase 2.4L (Novozyme A/S, Bagsvaerd, Denmark), which is a liquid product that contains about 9% active protease by weight of the liquid. The protease component was mixed with water and preheated to 55 °C (Water + Protease 55 °C) prior to being added to the extruder. In certain trials, an additional protease component was used in combination with the Alcalase 2.4L. A IN KOH solution (1st KOH) was used in each trial, and a 45% w/v KOH solution (2nd KOH) was used in certain trials. Each trial included a fat component (Oil) that was added to extruder, which included high oleic safflower oil, soy oil, coconut oil, arachidonic acid (ARA) oil (45% ARA), docosahexaenoic acid (DHA) oil (45% DHA), mixed carotenoids (e.g., beta-carotene, lutein, lycopene), vitamin A palmitate, vitamin A, vitamin D, vitamin E, vitamin K, and ascorbyl palmitate. In certain trials, a carbohydrate component, vitamins, and minerals (Powder 2) were added to the extruder.

[0074] In each trial, the WPC powder and a protease component-water mixture were added to the first barrel of the extruder to hydrate the WPC. The first barrel was maintained at room temperature (e.g., 20 °C to 25 °C). The 1 st KOH was used as a pH adjuster to raise the pH of the material within the extruder and was added to the second barrel of the extruder. The WPC, water, protease component, and 1 st KOH were mixed within the extruder and conveyed to subsequent barrels of the extruder. During the initial mixing and conveying of the material within the extruder, the hydrolysis of the WPC began. The Oil was added to the fifth barrel of the extruder. To sufficiently mix the Oil with the WPC, water, protease component, and 1 st KOH, the extruder included one or more high shear elements to emulsify the material within the extruder to form an emulsion. In certain trials, as the emulsion was further mixed and conveyed within the extruder, the Powder 2 was added to the eleventh barrel of the extruder and mixed together with the emulsion in the extruder. In certain trials, the 2nd KOH was used as a pH adjuster to raise the pH of the material within the extruder and was added to the eleventh barrel of the extruder. The temperatures of the second barrel through the eleventh barrel of the extruder were maintained at approximately 55 °C to heat the material within the extruder. The temperatures of the twelfth barrel through the fourteenth barrel were maintained at approximately 98 °C to promote inactivation of the protease component. Samples of the emulsion exiting the extruder were collected and cooled on ice for further analysis.

[0075] The feed rates for the materials added to the extruder in trials 1-32 are listed below in Table 2. In addition, the protease concentration, the approximate weight ratio of active protease to protein, the total solids content of the emulsion exiting the extruder, the protein content of the emulsion, the pH of the emulsion, and the degree of hydrolysis (DH) of the hydrolyzed protein in the emulsion are shown in Table 2. TABLE 2

31 3.2 4 2.5 1.0 0.225: 100 5.6 0.11 10.6 6.16 8.48

32 3.2 4 2.5 1.0 0.225: 100 5.6 0.15 10.6 6.47 11.33

[0076] The protease concentration and active protease to protein ratio in Table 2 were determined in the same manner as described above Example 1. As seen in Table 2, the emulsions that were produced contained hydrolyzed protein having a DH ranging from about 5% to about 15%. In trials 1-6 the protease concentration was about 20%, whereas trials 7-10 used a 10% protease concentration, trials 1 1-19 used a 5% protease concentration, and trials 20-32 used a 2.5%) protease concentration. It should be noted that trials 29-32 included a protease component in addition to the Alcalase 2.4L. In trials 29 and 30, Flavourzyme protease (Novozyme A/S, Bagsvaerd, Denmark) was used at a 1.25% protease concentration. In trials 31 and 32, Neutrase 0.8L protease (Novozyme A/S, Bagsvaerd, Denmark) was used at a 1.25% protease concentration.

[0077] As can be appreciated from the data shown in Table 2, the trials that produced emulsions containing hydrolyzed protein with low DH values were generally the trials in which Powder 2 was added to the extruder without adding the 2nd KOH stream. The low DH values observed trials 2, 15, and 25 was likely due to a reduction in the pH of the material within the extruder, which affects the activity of the protease component. When the 2nd KOH was added to the extruder, the pH of the material within the extruder generally remained above 6, which resulted in the emulsions having protein with DH values generally above 7%. These DH values were obtained even when using a low protease concentration of 2.5%. In trials 1-32, the total solids content of the emulsion exiting the extruder was from 30% to 90%, and the protein content was from 5% to 35% based on the weight of total solids of the emulsion.

[0078] To the extent that the term "includes" or "including" is used in the specification or the claims, it is intended to be inclusive in a manner similar to the term "comprising" as that term is interpreted when employed as a transitional word in a claim. Furthermore, to the extent that the term "or" is employed (e.g., A or B) it is intended to mean "A or B or both." When the applicants intend to indicate "only A or B but not both" then the term "only A or B but not both" will be employed. Thus, use of the term "or" herein is the inclusive, and not the exclusive use. [0079] While the present application has been illustrated by the description of embodiments thereof, and while the embodiments have been described in considerable detail, it is not the intention of the Applicant to restrict or in any way limit the scope of the appended claims to such detail. Additional advantages and modifications will readily appear to those skilled in the art. Therefore, the application, in its broader aspects, is not limited to the specific details, the representative compositions or formulations, and illustrative examples shown and described. Accordingly, departures may be made from such details without departing from the spirit or scope of the general disclosure described herein.

Claims

WHAT IS CLAIMED IS:

1. A method of preparing a nutritional powder comprising:

adding an intact protein source, a protease component, a fat component, and water to an extruder to form a slurry; and

emulsifying the slurry within the extruder to form an emulsion, wherein the emulsion has a total protein content of 5% to 35% based on the weight of the solids of the emulsion, and wherein at least a portion of the protein is hydrolyzed within the extruder to achieve a degree of hydrolysis of 5% to 30%; and

drying the emulsion and milling the dried emulsion to form a nutritional powder.

2. The method of claim 1, further comprising adding a pH adjuster to the extruder to maintain a pH of the slurry at from 5 to 9.

3. The method of claim 1 or claim 2, further comprising heating the slurry to a temperature of from 35 °C to 75 °C.

4. The method of any one of claims 1 to 3, further comprising heating the emulsion to a temperature of from 80 °C to 105 °C to promote inactivation of the protease component.

5. The method of any one of claims 1 to 4, wherein the emulsion comprises from 30% to 90% by weight solids.

6. The method of any one of claims 1 to 5, wherein the intact protein source and the protease component are added to the extruder in amounts so that a weight ratio of active protease to protein is from 0.2: 100 to 2: 100.

7. The method of any one of claims 1 to 5, wherein the intact protein source and the protease component are added to the extruder in amounts so that a weight ratio of active protease to protein is from 0.2: 100 to 0.9: 100.

8. The method of any one of claims 1 to 7, further comprising adding to the extruder at least one of a carbohydrate component, vitamins, and minerals.

9. The method of any one of claims 1 to 8, wherein the protein of the emulsion has a degree of hydrolysis of 10% to 15%.

10. The method of any one of claims 1 to 9, wherein the protease component comprises a protease derived from Bacillus sp.

11. The method of any one of claims 1 to 9, wherein the protease component comprises a protease derived from Aspergillus oryzae.

12. The method of any one of claims 1 to 9, wherein the protease component comprises a mixture of proteases.

13. The method of any one of claims 1 to 12, wherein the intact protein source is in powder form.

14. The method of any one of claims 1 to 13, wherein the intact protein source comprises at least one of whey protein concentrate, whey protein isolate, casein, sodium caseinate, calcium caseinate, potassium caseinate, milk protein concentrate, milk protein isolate, non-fat dry milk, soy protein concentrate, soy protein isolate, pea protein concentrate, pea protein isolate, rice protein concentrate, rice protein isolate, potato protein concentrate, potato protein isolate, algal protein concentrate, algal protein isolate, corn protein concentrate, corn protein isolate, wheat protein concentrate, wheat protein isolate, oat protein concentrate, oat protein isolate, canola protein concentrate, canola protein isolate, sunflower protein concentrate, sunflower protein isolate, soy flour, peanut flour, and combinations thereof.

15. The method of claim 1, further comprising:

adding a pH adjuster to the extruder to maintain a pH of the slurry at from 5 to 9;

heating the slurry to a temperature of from 35 °C to 75 °C; and heating the emulsion to a temperature of from 80 °C to 105 °C to promote inactivation of the protease component;

wherein the intact protein source comprises whey protein concentrate, the protease component comprises a protease derived from Bacillus licheniformis, and the protein of the emulsion has a degree of hydrolysis of 10% to 15%.

16. The method of any one of claims 1 to 15, wherein the emulsion has a total protein content of 10%) to 20% based on the weight of the solids of the emulsion.

17. A nutritional powder prepared according to the method of any one of claims 1 to 16.