Thermomechanical degradation of starch

Abstract

The invention relates to methods of thermomechanical degradation of starch, which allow the use of starch that has not been subjected to any pretreatment. By controlling the conditions of the thermomechanical degradation, different starch extrudates can be obtained. For example, low-viscosity extruded starch (LVES) and thermoreversible gelling extruded starch (TRES) may be obtained by subjecting native granular starch and water to thermomechanical degradation. The optional addition of a starch-modifying agent leads to modified extruded starch (MOES). The invention also relates, inter alia, to compositions obtainable by the methods of the invention; products comprising said compositions; and various applications of said compositions.

Description

[0001] P138201PC00

[0002] Title: THERMOMECHANICAL DEGRADATION OF STARCH

[0003] FIELD

[0004] The invention relates to the field of food technology and starch applications. More in particular, it relates to thermomechanical degradation of untreated starch, and to tuning the conditions for the thermomechanical degradation so as to obtain different extruded products.

[0005] BACKGROUND

[0006] Starch is the most common carbohydrate in human diets. It contains polymers of glucose that are connected via glycosidic bonds. Starch usually consists of two types of molecules: amylose (which is normally linear and helical), and amylopectin (which is typically branched). Major sources of starch include, but are not limited to, root vegetables (particularly potatoes and cassava) and cereals (such as rice, wheat, and maize).

[0007] Native granular starch is typically insoluble in cold water or alcohol, and can be processed in various ways to obtain starch compositions having a wide range of different properties, such as viscosity, water solubility, gel formation, and the like.

[0008] Prior to further processing, however, starch is typically subjected to a pretreatment which degrades and / or (chemically) modifies the starch. There is a strong prejudice in the art that this pretreatment is necessary to prepare the starch for the further processing.

[0009] The pretreatment comprises for example hydrolysis (by enzymes, acids, and / or bases), the addition of additives, hydrothermal treatment, and the like. Usually, the pretreatment aims to prepare the native starch granules by disrupting their crystalline structure, increasing their surface area, and / or making them more accessible or reactive to chemical, physical, or enzymatic agents. Other forms of pretreatment include physical pretreatment and thermal pretreatment.

[0010] Thus, typical disadvantages of pretreatments are that they involve the use of chemicals, and / or requires time and / or energy.

[0011] Moreover, different pretreatments usually need to be selected in case various different pretreated starch compositions need to be prepared, which may require the need for using different equipment, chemicals, and so forth.

[0012] Consequently, there is a desire to provide methods of modifying and / or degrading starch that allow the avoidance of any pretreatment. In particular, there is a desire to provide methods of producing modified and / or degraded starch that are more environmentally friendly, viz. that reduce or avoid the need for chemicals (used for pretreatment or as catalysts) and / or energy. Moreover, it is desired that methods of modifying and / or degrading starch be provided that allow a shorter period of time necessary to prepare the modified and / or degraded starch. Additionally, it is desired that methods of modifying and / or degrading starch be provided that may produce different types of modified and / or degraded starch, without the need of various pieces of equipment.

[0013] There is thus a need for methods of modifying and / or degrading starch that address one or more of the abovementioned problems and / or desires.

[0014] SUMMARY

[0015] In one aspect, the invention relates to a method for providing an extruded starch composition, wherein the method comprises the steps of:

[0016] (a) providing a starting composition of a native granular starch, wherein the starting composition has a moisture content in a range of from 15 to 35 wt.% relative to the total weight of the starting composition, and wherein said native granular starch has not been subjected to any pretreatment; preferably the starting composition is free of any nonstarch additives; more preferably the starting composition is free of any additives;

[0017] (b) subjecting the starting composition to thermomechanical degradation by an extrusion process in an extruder barrel; and

[0018] (c) obtaining and optionally drying the extrudate and / or subjecting the extrudate to a step of particle size reduction; wherein preferably the extrusion process is a single-step extrusion process.

[0019] The invention also pertains to an extruded starch composition obtainable by the method according to the invention.

[0020] The invention further relates to a food item, a feed item, a thickening agent, an adhesive, a cosmetic product, paper, or a construction material, comprising an extruded starch composition obtainable by the method of the invention.

[0021] The invention additionally pertains to the use of an extruded starch composition according to the invention as a food ingredient, a feed ingredient, a thickening agent, an adhesive, an ingredient for a cosmetic product, as an ingredient for the production of paper, and / or as a component of a construction material.

[0022] LEGEND TO THE FIGURE

[0023] Figure 1 : Rheology plots showing thermoreversible properties of exemplary TRES compositions (samples 1, 7 and 12 of Table 17). Squares indicate the Storage modulus G’ (Pa) and triangles indicate the Loss modulus G” (Pa).

[0024] DETAILED DESCRIPTION

[0025] The invention is based on the judicious insight that extruded starch compositions can be manufactured in a sustainable and “green” fashion by subjecting native granular starch to a thermomechanical degradation process, preferably an extrusion process. In particular, the methods of the invention allow the avoidance of any pretreatment of the starch prior to thermomechanical degradation. Moreover, methods of the invention are more environmentally friendly than known processes, and in particular allow the reduction or avoidance of chemicals and / or energy. Furthermore, methods of the invention allow a shorter period of time necessary to prepare the extruded starch, in particular because any pretreatment of the starch can be dispensed with.

[0026] Without wishing to be bound by theory, the inventors believe that surprisingly, the conditions during the thermomechanical degradation may achieve the same goals usually pursued by pretreatment, viz. disrupting the crystalline structure of the native starch granules, increasing the surface area of the native starch, and / or making the starch more accessible and / or reactive to starch-modifying agents. In particular, the pressure, temperature, and / or energy applied on the starch in thermomechanical degradation is believed to contribute hereto. Still without wishing to be bound by theory, the inventors believe that the formation of very reactive species, for example free radicals or oxidative species, during thermomechanical degradation may act as highly energetic initiators for starch degradation and / or modification. Moreover, the inventors have found that a broad range of different extruded starch compositions having different properties can be obtained when applying the method of the invention. Tuning of the conditions under which the thermomechanical degradation is performed, and / or adjusting the starting materials and amounts thereof may be utilized to decide which type of extruded starch is obtained.

[0027] For example, low-viscosity extruded starch (herein referred to as “LVES”) and thermoreversible gelling extruded starch (herein referred to as “TRES”) may be obtained by subjecting native granular starch and water to thermomechanical degradation.

[0028] Thus, in one embodiment the method of the invention is a method for providing LVES, in particular an LVES composition.

[0029] In another embodiment, the method of the invention is a method for providing TRES, in particular a TRES composition.

[0030] The optional addition of a starch-modifying agent leads to modified extruded starch (herein referred to as “MOES”). Thus, in yet another embodiment the method of the invention is a method for providing MOES, in particular a MOES composition. In this embodiment, in step (b) of said method the extrusion process is performed in the presence of at least one starch-modifying agent to modify the starch in situ.

[0031] Unless stated otherwise, for example because reference is made to a method for providing LVES, TRES, or MOES, all preferences and embodiments mentioned herein relate to any one of LVES, TRES, and MOES preparation, and may be combined with one another.

[0032] Starting composition

[0033] In step (a) of the method of the invention, a starting composition is provided. The starting composition comprises native granular starch and water.

[0034] As used herein, “native granular starch” refers to starch that is in its natural, unmodified form as it is extracted from a plant source. In this state, the starch granules typically retain their original crystalline and molecular structure as formed in the plant, which may include a specific arrangement and amount of amylose and amylopectin molecules.

[0035] In principle, any type of starch can be used in the methods of the invention.

[0036] Preferably, the native granular starch is a starch selected from the group consisting of waxy starch, amylose starch, and regular starch. More preferably, the native granular starch is selected from the group consisting of corn starch, potato starch, tapioca starch, faba starch, pea starch, wheat starch, arrowroot starch, sweet potato starch, yam starch, taro starch, and combinations thereof. More preferably, the native granular starch is potato starch, com starch, tapioca starch, faba starch, pea starch, or a combination thereof. Even more preferably, the native granular starch is potato starch, com starch, tapioca starch, or a combination thereof. More preferably, the native granular starch is potato starch or tapioca starch. More preferably still, the native granular starch is potato starch. Most preferably, the native granular starch is native potato starch.

[0037] As used herein, “potato” refers to a plant of the species Solanum tuberosum.

[0038] As used herein, “tapioca starch” refers to starch extracted from the tubers of the cassava plant. As used herein, “cassava” refers to a plant of the genus Mani hot.jand includes the species Manihot esculenta, syn. M. utilissima, also called manioc, mandioca or yuca, and also M. palmata, syn. M. dulcis. Cassava is also known as manioc, mandioca, or yuca.

[0039] As used herein, “com” refers to a plant of the species Zea mays.

[0040] As used herein, “faba” refers to a plant of the species Vicia faba.

[0041] As used herein, “pea” refers to the seed of a plant of the species Pisum sativum (also known as Lathyrus ole race us). Cajanus cajan (pigeon pea), or Vigna unguiculata (cowpea); preferably Pisum sativum.

[0042] As used herein, “wheat” refers to a plant of the genus Triticim preferably of the species Triticum aestivum (common wheat).

[0043] As used herein, “arrowroot starch” refers to starch obtained from the rhizomes plant of the species Maranta arundinacea. Tacca leontopetaloides, or Canna indica: preferably Maranta arundinacea.

[0044] As used herein, “sweet potato” refers to a plant of the species Ipomoea batatas.

[0045] As used herein, “yam” refers to a plant of the genus Dioscorea.

[0046] As used herein, “taro” refers to a plant of the species Colocasia esculenta.

[0047] Preferably, the native granular starch comprises at least 55 wt% of amylopectin, more preferably at least 60 wt%, more preferably at least 65 wt%, and most preferably at least 70 wt%. Preferably, the native granular starch comprises amylopectin in an amount in a range of from 55 to 99 wt%, more preferably from 60 to 98 wt%, more preferably from 65 to 97 wt%, and most preferably from 70 to 95 wt%.

[0048] Preferably, the native granular starch comprises at most 45 wt% of amylose, more preferably at most 40 wt%, more preferably at most 35 wt%, and most preferably at most 30 wt%. Preferably, the native granular starch comprises amylose in an amount in a range of from 1 to 45 wt%, more preferably from 2 to 40 wt%, more preferably from 3 to 35 wt%, and most preferably from 5 to 30 wt%.

[0049] The starting composition may have a moisture content in a range of from 10 to 50 wt%, and typically of from 15 to 35 wt.%, more commonly of from 17 to 32 wt%, relative to the total weight of the starting composition. Preferably, said starting composition has a moisture content in a range of from 18 to 30 wt%, more preferably of from 19 to 28 wt.%, and most preferably of from 20 to 25 wt%, relative to the total weight of the starting composition.

[0050] Preferably, the starting composition comprises the native granular starch in an amount of at least 60 wt%, more preferably at least 65 wt%, more preferably at least 70 wt%, more preferably at least 72 wt%, more preferably at least 75 wt%, and most preferably at least 77 wt%, as compared to the total weight of the starting composition.

[0051] In methods of the invention the native granular starch has not been subjected to any pretreatment. This may reduce the time required for the starch modification process, may reduce the energy required for said process, and may reduce the need for chemicals (or decrease the amount of chemicals required for said process).

[0052] As used herein, “pretreatmenf ’ typically refers to any chemical treatment that chemically modifies the native granular starch. Preferably, “pretreatmenf ’ refers to any chemical, physical, and / or thermal treatment that chemically, physically, and / or thermally modifies and / or degrades the native granular starch. More preferably, “pretreatmenf’ is any treatment that disrupts the crystalline structure of the native granular starch, increases the surface area of the native granular starch, makes the starch more accessible and / or reactive to starch-modifying agents, and / or chemically modifies the native granular starch.

[0053] In this context, it will be understood that “pretreatmenf’ does not include contacting the native granular starch with a starch-modifying agent if this contacting does not lead to chemical modification of the native granular starch, for example because both the native granular starch and the starch-modifying agent are present as solids, and no chemical reaction can occur.

[0054] Preferably, the starting composition is free of any non-starch additives; and more preferably the starting composition is free of any additives. As used in this context, “additives” relates to any compound other than native granular starch, starch-modifying agents, and water. In particular, “additives” may refer to colorants, plasticizers (such as glycerol and sorbitol), stabilizers, emulsifiers (such as lecithin and monoglycerides), antioxidants (such as ascorbic acid), preservatives (such as sodium benzoate and potassium sorbate), and fillers (such as cellulose and maltodextrin).

[0055] Furthermore, “additives” may also refer to catalysts. Preferably, the starting composition is substantially free of catalysts. More preferably, the starting composition is free of catalysts. As used herein, a “catalyst” is any substance that increases the reaction rate of the reaction between the starch and another reagent, and is itself not consumed by the reaction.

[0056] It will be understood that when the method of the invention is a method for providing LVES or TRES, it is preferred that no starch-modifying agent is used. Thus, for LVES and TRES, it is preferred that the only substances subjected to the extrusion process are the native granular starch and water.

[0057] Thus, for the preparation of LVES or TRES, it is preferred that the starting composition essentially consists of the native granular starch, and water.

[0058] As used herein, “essentially consists of’ indicates that the components make up at least 95 wt% as compared to the total weight of the starting composition, preferably at least 96 wt%, more preferably at least 97 wt%, more preferably at least 98 wt%, more preferably at least 99 wt%, more preferably at least 99.5 wt%, more preferably at least 99.9 wt%, and most preferably about 100 wt%.

[0059] Preferably, when the method of the invention is a method for providing LVES or TRES, no other substances are introduced into the extruder barrel than the starting composition, and optionally water, and optionally air. It will be understood that in the previous sentence, “in the methods of the invention” refers to immediately before starting extrusion, simultaneous with starting extrusion, and during extrusion. As mentioned above, when the method of the invention is a method for providing MOES, then in step (b) of said method the extrusion process is performed in the presence of at least one starch-modifying agent to modify the starch in situ.

[0060] When preparing MOES, the starting composition may comprise the at least one starch-modifying agent, provided that contacting the native granular starch and the at least one starch-modifying agent does not chemically modify the native granular starch before the native granular starch is introduced to the extruder barrel in which the extrusion process is performed.

[0061] However, also when preparing MOES it is more preferred that the starting composition does not comprise the at least one starch-modifying agent. In that case, when preparing MOES, the at least one starch-modifying agent is contacted with the starting composition in the extruder barrel, which can be done immediately before the extrusion process is started, simultaneously with starting the extrusion process, and / or during the extrusion process by feeding the at least one starch-modifying agent into the extruder barrel. Said feeding may be continuous or discontinuous, but continuous feeding is preferred.

[0062] If the starting composition comprises the at least one starch-modifying agent, it is preferred that said starch-modifying agents are present in a total amount in a range of from 0.001 to 15 wt%, preferably from 0.01 to 5 wt%, more preferably in a range of from 0.10 to 3 wt%, more preferably in a range of from 0.20 to 2 wt%, more preferably in a range of from 0.30 to 1.5 wt%, and most preferably in a range of from 0.40 to 1.20 wt%, as compared to the dry weight of the native granular starch.

[0063] Consequently, when preparing MOES, it is preferred that the starting composition essentially consists of the native granular starch, water, and the at least one starch- modifying agent. More preferably, the starting composition essentially consists of the native granular starch, and water. In the latter case, it is preferred that no other reagents than the at least one starch-modifying agent and optionally water are contacted with the starting composition immediately before or during the thermomechanical degradation.

[0064] If the starting composition comprises multiple components, the starting composition can be provided by contacting the required components, for example by mixing, blending, shaking, stirring, and the like. Contacting the required components may be performed prior to introducing the starting composition to the extruder, in particular immediately before introducing the starting composition to the extruder, and / or the contacting can take place in the extruder. Contacting the required components may be carried out immediately before the extrusion process is started.

[0065] If the method of the invention is for providing MOES, it is preferred that at most three different starch-modifying agents are used; more preferably, at most two different starch-modifying agents are used; and most preferably, only one starch-modifying agent is used.

[0066] Preferably, the at least one starch-modifying agent is selected from the group consisting of crosslinkers, hydrolyzing agents, oxidizing agents, etherification agents, esterification agents, grafting agents, and phosphorylation agents.

[0067] More preferably, the at least one starch-modifying agent is selected from the group consisting of citric acid, epichlorohydrin, sodium trimetaphosphate (NasPsC ), sodium tripolyphosphate (NasPsOio), tetrasodium pyrophosphate (E ^O?), adipic anhydride, hydrochloric acid, sulfuric acid, nitric acid, a-amylase, B-amylase, glucoamylase (also known as amyloglucosidase), pullulanase, isoamylase, hydrogen peroxide (H2O2), potassium permanganate (KMnCU), sodium hypochlorite, ozone, sodium periodate, and nitrogen dioxide, ethylene oxide, propylene oxide, epichlorohydrin, quaternary ammonium compounds, sodium monochloroacetate, phosphoric acid, acetic anhydride, propionic anhydride, octenylsuccinic acid, acetic acid, butyric acid, ethanol, glycerol, acetyl chloride, lauric acid, stearic acid, myristic acid, palmitic acid, arachidic acid, behenic acid, lignoceric acid, cerotic acid, montanic acid, melissic acid, acrylamide, methacrylamide, polyethylene glycol, chitosan, acrylic acid, methyl acrylate, ethyl acrylate, 2-chloroethyl vinyl ether, 2-ethylhexyl acrylate, butyl acrylate, trimethylolpropane triacrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, hydroxyethyl methacrylate, glycidyl methacrylate, vinyl acetate, styrene, guar gum, xanthan gum, vinyltri ethoxy silane, 3 -aminopropyltri ethoxy silane, 3- methacryloxypropyltrimethoxysilane, glycidyloxypropyltrimethoxysilane, chloropropyltriethoxysilane, phosphoryl chloride, phosphorus pentoxide, sodium dihydrogen phosphate, di sodium hydrogen phosphate, aminotrimethylenephosphonic acid, tributyl phosphate, starch phosphorylase, phytase, glucose-6-phosphate dehydrogenase, nucleotide sugar-dependent glycosyltransferases, hexokinase, and starch synthase.

[0068] Preferably, the polyethylene glycol has a molecular weight in a range of from 200 Da to 100 kDa, more preferably of from 500 Da to 75 kDa, more preferably of from 1 kDa to 50 kDa, even more preferably of from 2 kDa to 35 kDa, and most preferably of from 5 kDa to 25 kDa.

[0069] Thermomechanical degradation

[0070] In step (b) of methods of the invention the starting composition is subjected to thermomechanical degradation by an extrusion process. The extrusion process takes place in an extruder barrel.

[0071] In the case of preparing MOES, the extrusion process is carried out in the presence of at least one starch-modifying agent. In particular, the starch-modifying agent typically results in chemical modification of the native granular starch in situ. Advantageously, however, the thermomechanical degradation may chemically and physically alter the native granular starch as well. Without wishing to be bound by theory, the thermomechanical degradation may degrade the native granular starch by breaking up the glycosidic bonds within the native granular starch, so as to make the starch more accessible and / or more reactive towards the at least one starch-modifying agent. Logicially, these considerations may also hold when providing LVES and TRES, because also in that case the native granular starch is subjected to thermomechanical degradation.

[0072] Preferably, a minimum number of ingredients is used in the method of the invention. This ensures the most environmentally friendly method as possible.

[0073] As such, for the preparation of LVES or TRES it is preferred that during the extrusion process no substances are introduced to the extruder barrel other than the starting composition, and optionally water. It will be understood that as used in the previous sentence “substances” preferably does not include air. Consequently, it is preferred that during the extrusion process to prepare LVES or TRES, no substances are introduced to the extruder barrel other than the starting composition, the at least one starch-modifying agent, air, and optionally water.

[0074] As noted above, for the preparation of MOES, the at least one starch-modifying agent and water may also be present in the starting composition. In that case, it is preferred that only the starting composition is provided to the extruder barrel, and optionally additional water.

[0075] The (additional) water may be fed continuously into the extruder barrel to maintain the moisture content of the composition during extrusion (herein referred to as the “extrusion mass” or “melt”) at a desired level. The water may be introduced to the extruder barrel in the form of steam. For all embodiments, it is preferred that the moisture content of the extrusion mass is in a range of from 10 to 50 wt%, relative to the total weight of the extrusion mass, more preferably of from 12 to 40 wt%, more preferably of from 15 to 35 wt%, more preferably of from 17 to 32 wt%, more preferably of from 18 to 31 wt%, even more preferably of from 19 to 30 wt%, and most preferably of from 20 to 27 wt%.

[0076] In the preparation of LVES, it is preferred that the moisture content of the melt during extrusion in a range of from 18 to 25 wt%, more preferably of from 19 to 23 wt%, and most preferably of from 20 to 22 wt%, as compared to the total weight of the melt.

[0077] In the preparation of TRES or MOES, it is most preferred that the moisture content of the melt during extrusion in a range of from 20 to 26 wt%, as compared to the total weight of the melt.

[0078] Preferably, the extrusion process in the methods of the invention is a single-step extrusion process.

[0079] Preferably, an extrusion setup used in the extrusion process of methods of the invention comprises an extruder comprising a barrel section comprising at least 3 blocks, preferably at least 5 blocks, the first block of the barrel section comprising a feed inlet adapted for feeding the feed composition into the extruder, the second block, located downstream of the first block of the barrel section, comprising a water inlet adapted for introducing water into the extruder, and one or more further downstream blocks adapted to setting the temperature along the barrel section to comprise an increasing temperature gradient, said extruder further comprising a die section located downstream of the barrel section, and one or more screw elements adapted to convey the feed composition through the barrel section to the die section. The first block in the barrel section comprises a feed inlet, adapted for feeding a feed composition as herein defined into the extruder. The second block in the barrel section, located downstream of the first block, comprises a water inlet, adapted for introducing water into the extruder so as to attain the desired moisture content. The first and the second block are preferably operated under more or less ambient conditions (20 - 30 °C). One or more further downstream blocks in the barrel section are preferably equipped with means for heating and cooling, so as to allow for setting the temperature along the barrel section to comprise an increasing temperature gradient. In preferred embodiments, the temperature increases stepwise to a maximum temperature of 100 - 250 °C, more preferably 130 - 180 °C, even more preferably 140 - 160 °C.

[0080] Although the barrel section must comprise an increasing temperature gradient, it is conceivable that in some setups, the barrel section may comprise one or more barrel parts in which there is a decreasing temperature gradient, or a constant temperature. Such barrel parts may be combined with for example one, two or more barrel parts with an increasing temperature gradient, as the skilled person appreciates.

[0081] The barrel section furthermore comprises a die section located downstream of the barrel section, and one or more screw elements adapted to convey the feed composition through the barrel section to the die section. In preferred embodiments, the barrel section is equipped with a co-rotating twin screw. Further preferably, the screw configuration comprises reversed pitch elements and conveying elements, preferably alternatingly. In further preferred embodiments, the screw configuration comprises 2 - 10 reversed pitch elements. Reversed pitch elements are preferably located of from 10 D to 20 D. In much preferred embodiments, a reversed pitch element, preferably the reversed pitch element is followed downstream by a kneading block, preferably having a stagger angle of between 30 and 60 °, most preferably between 30 and 45 °. In further preferred embodiments, the die section comprises a die having one, or two or multiple outlets, preferably one or two outlets, through which outlet(s) the extruded feed mass exits the extruder.

[0082] During the extrusion process several conditions such as pressure, the temperature of the melt at the die of the extruder, and specific mechanical energy (SME) may be employed. Furthermore, the barrel temperature during extrusion may also be specified.

[0083] As the skilled person is aware, the barrel temperature may not be the same as the temperature of the melt during extrusion (in particular at the die of the extruder). The friction exerted on the extrusion mass may increase the melt temperature as compared to the barrel temperature. Simultaneously, depending on the extruder design, at high throughputs the melt may not spend sufficient time in a barrel section to attain the temperature of the barrel section. At any rate, the skilled person is aware how to tune the extrusion conditions (in particular the throughput, moisture content, barrel temperature, and pressure) to achieve the desired temperature of the melt at the die of the extruder.

[0084] Unless indicated otherwise, as used herein “melt” or “extrusion mass” refers to the composition in the extruder barrel during the extrusion process. It will be understood that the melt or extrusion mass has already been subjected to the extrusion process to such an extent that it differs from the starting composition.

[0085] Unless indicated otherwise, as used herein “SME” (in kWh / kg) is the specific mechanical energy transferred from the extruder to the starting composition; P (in bar) is the pressure at the die of the extruder; and T (in °C) is the melt temperature at the die of the extruder. The skilled person is aware how to tune the extrusion conditions (in particular the throughput, moisture content, barrel temperature, pressure, screw speed, and torque) to achieve the desired SME during extrusion.

[0086] The barrel temperature may be denoted as TB. Unless stated otherwise, preferably TB or the phrase “temperature in a barrel section” or similar phrasing refers to the temperature in the barrel section of an extruder immediately preceding the die of said extruder, for example the sixth barrel section in exemplary extruders as described herein.

[0087] Preferably, the pressure P is in a range of from 1 to 90 bar, more preferably of from 2 to 70 bar, and more preferably of from 3 to 60 bar.

[0088] In the preparation of LVES, it is preferred that pressure P is in a range of from 8 to 60 bar; and most preferably of from 10 to 56 bar. For LVES, exemplary values for P are about 10 bar, about 11 bar, about 12 bar, about 13 bar, about 14 bar, about 15 bar, about 16 bar, about 18 bar, about 20 bar, about 21 bar, about 23 bar, about 24 bar, about 28 bar, about 32 bar, about 35 bar, about 39 bar, about 40 bar, and about 56 bar.

[0089] In the preparation of TRES, it is preferred that pressure P is in a range of from 5 to 50 bar, most preferably of from 6 to 47 bar. In the preparation of MOES, it is preferred that pressure P is in a range of from 2 to 40 bar, most preferably of from 3 to 39 bar.

[0090] Preferably, the temperature of the extrusion barrel during the extrusion process is in a range of from 120 to 180 °C, more preferably of from 125 to 170 °C, and most preferably of from 130 to 165 °C.

[0091] It will be understood that when using the exemplary extruder barrel of the invention having six barrel blocks, for all embodiments (i.e. the preparation of LVES, TRES, or MOES) it is preferred that in the first barrel block the temperature is not regulated, and is preferably ambient, more preferably in a range of from 15 to 35 °C, more preferably of from 18 to 30 °C, and most preferably of from 20 to 25 °C.

[0092] In the preparation of LVES, it is preferred that the temperature of the extrusion barrel during the extrusion process is in a range of from 140 to 160 °C; more preferably of from 145 to 155 °C, and most preferably of from 148 to 152 °C. When using an extruder barrel having six barrel blocks, in particular the exemplary extruder barrel as disclosed herein, it is preferred that in the preparation of LVES:

[0093] (a) the temperature in the second barrel block is in a range of from 20 to 40 °C, more preferably from 25 to 35 °C, more preferably from 27 to 33 °C, and most preferably about 30 °C;

[0094] (b) the temperature in the third barrel block is in a range of from 30 to 50 °C, more preferably from 35 to 45 °C, more preferably from 37 to 43 °C, and most preferably about 40 °C;

[0095] (c) the temperature in the fourth barrel block is in a range of from 80 to 100 °C, more preferably from 85 to 95 °C, more preferably from 87 to 93 °C, and most preferably about 90 °C;

[0096] (d) the temperature in the fifth barrel block is in a range of from 115 to 135 °C, more preferably from 120 to 130 °C, more preferably from 122 to 128 °C, and most preferably about 125 °C; and / or

[0097] (e) the temperature in the sixth barrel block is in a range of from 140 to 160 °C; more preferably of from 145 to 155 °C, more preferably of from 148 to 152 °C; and most preferably about 150 °C. In the preparation of TRES, it is preferred that the temperature of the extrusion barrel during the extrusion process is in a range of from 130 to 150 °C; more preferably of from 135 to 145 °C, and most preferably of from 138 to 142 °C. When using an extruder barrel having six barrel blocks, in particular the exemplary extruder barrel as disclosed herein, it is preferred that in the preparation of TRES:

[0098] (a) the temperature in the second barrel block is in a range of from 50 to 70 °C, more preferably from 55 to 65 °C, more preferably from 57 to 63 °C, and most preferably about 60 °C;

[0099] (b) the temperature in the third barrel block is in a range of from 70 to 90 °C, more preferably from 75 to 85 °C, more preferably from 77 to 83 °C, and most preferably about 80 °C;

[0100] (c) the temperature in the fourth barrel block is in a range of from 90 to 110 °C, more preferably from 95 to 105 °C, more preferably from 97 to 103 °C, and most preferably about 100 °C;

[0101] (d) the temperature in the fifth barrel block is in a range of from 110 to 130 °C, more preferably from 115 to 125 °C, more preferably from 117 to 123 °C, and most preferably about 120 °C; and / or

[0102] (e) the temperature in the sixth barrel block is in a range of from 130 to 150 °C; more preferably of from 135 to 145 °C, more preferably of from 138 to 142 °C, and most preferably about 140 °C.

[0103] In the preparation of MOES, it is preferred that the temperature of the extrusion barrel during the extrusion process is in a range of from 150 to 170 °C; more preferably of from 155 to 165 °C, and most preferably of from 158 to 162 °C. When using an extruder barrel having six barrel blocks, in particular the exemplary extruder barrel as disclosed herein, it is preferred that in the preparation of MOES:

[0104] (a) the temperature in the second barrel block is in a range of from 30 to 50 °C, more preferably from 35 to 45 °C, more preferably from 37 to 43 °C, and most preferably about 40 °C;

[0105] (b) the temperature in the third barrel block is in a range of from 50 to 70 °C, more preferably from 55 to 65 °C, more preferably from 57 to 63 °C, and most preferably about 60 °C; (c) the temperature in the fourth barrel block is in a range of from 80 to 100 °C, more preferably from 85 to 95 °C, more preferably from 87 to 93 °C, and most preferably about 90 °C;

[0106] (d) the temperature in the fifth barrel block is in a range of from 110 to 130 °C, more preferably from 115 to 125 °C, more preferably from 117 to 123 °C, and most preferably about 140 °C; and / or

[0107] (e) the temperature in the sixth barrel block is in a range of from 150 to 170 °C; more preferably of from 155 to 165 °C, more preferably of from 158 to 162 °C, and most preferably about 160 °C.

[0108] Preferably, the temperature of the extrusion mass at the die of the extruder is in a range of from 120 to 200 °C, more preferably of from 125 to 195 °C.

[0109] In the preparation of LVES, it is preferred that the temperature of the extrusion mass at the die of the extruder is in a range of from 170 to 200 °C, more preferably of from 172 to 195 °C, and most preferably of from 175 to 191 °C. For LVES, exemplary values for the temperature of the melt at the die of the extruder are about 175 °C, about 176 °C, about 177 °C, about 179 °C, about 180 °C, about 181 °C, about 182 °C, about 183 °C, about 184 °C, about 185 °C, about 189 °C, about 190 °C, and about 191 °C.

[0110] In the preparation of TRES, it is preferred that the temperature of the extrusion mass at the die of the extruder is in a range of from 120 to 175 °C, more preferably of from 125 to 170 °C, and most preferably of from 131 to 161 °C.

[0111] In the preparation of MOES, it is preferred that the temperature of the extrusion mass at the die of the extruder is in a range of from 135 to 180 °C, more preferably of from 140 to 175 °C, and most preferably of from 145 to 169 °C.

[0112] Preferably, the SME during the extrusion process is at least 0.05 kWh / kg. More preferably, the SME is in a range of from 0.05 to 0.50 kWh / kg, more preferably of from 0.07 to 0.35 kWh / kg, and most preferably of from 0.08 to 0.30 kWh / kg. As the skilled person is aware, SME (in kWh / kg) is the specific mechanical energy transferred from the extruder to the starting composition. The SME may result from a combination of factors, such as material properties (e.g. viscosity and melt flow, thermal conductivity and heat capacity), process parameters (such as screw speed, feed rate, barrel temperature profile, screw design, shear rate, and the like), equipment and die design (for example die geometry, extruder efficiency, and so forth). The skilled person is aware how to tune these parameters to obtain a desired SME value.

[0113] In the preparation of LVES, it is preferred that the SME is in a range of from 0.140 to 0.230 kWh / kg, and most preferably of from 0.144 to 0.220 kWh / kg. For LVES, exemplary values for the SME are about 0.144 kWh / kg, about 0.148 kWh / kg, about 0.151 kWh / kg, about 0.153 kWh / kg, about 0.156 kWh / kg, about 0.159 kWh / kg, about

[0114] 0.161 kWh / kg, about 0.164 kWh / kg, about 0.165 kWh / kg, about 0.169 kWh / kg, about

[0115] 0.172 kWh / kg, about 0.176 kWh / kg, about 0.177 kWh / kg, about 0.190 kWh / kg, about

[0116] 0.191 kWh / kg, about 0.196 kWh / kg, about 0.207 kWh / kg, and about 0.220 kWh / kg.

[0117] In the preparation of TRES, it is preferred that the SME is in a range of from 0.080 to 0.250 kWh / kg, and most preferably of from 0.087 to 0.239 kWh / kg.

[0118] In the preparation of MOES, it is preferred that the SME is in a range of from 0.090 to 0.275 kWh / kg, more preferably of from 0.100 to 0.150 kWh / kg, and most preferably of from 0.110 to 0.137 kWh / kg.

[0119] Furthermore, the inventors found that exemplary results are obtained if a specific combination of P, T, and SME are used, which are defined as the “degradation factor”. The degradation factor as used herein refers to the parameter SME / (P / T), which can also be written as SME*T / P. The units for the degradation factor are kWh °C bar'1kg'1.

[0120] Preferably, the extrusion process is characterized by a degradation factor in a range of from 0.05 to 10 kWh °C bar'1kg'1, preferably in a range of from 0.20 to 9 kWh °C bar'1kg'1, and most preferably in a range of from 0.25 to 7 kWh °C bar'1kg'1; wherein SME (in kWh / kg) is the specific mechanical energy transferred from the extruder to the starting composition; P (in bar) is the pressure at the die of the extruder; and T (in °C) is the melt temperature at the die of the extruder.

[0121] In the preparation of LVES, it is preferred that the SME*T / P is in a range of from 0.40 to 3.80 kWh °C bar'1kg'1, and most preferably of from 0.45 to 3.78 kWh °C bar'1kg'1. For LVES, exemplary values for SME*T / P are about 0.45 kWh °C bar'1kg'1, about 0.67 kWh °C bar'1kg'1, about 0.70 kWh °C bar'1kg'1, about 0.76 kWh °C bar'1kg'1, about 0.87 kWh °C bar'1kg'1, about 1.06 kWh °C bar'1kg'1, about 1.18 kWh °C bar'1kg'1, about 1.30 kWh °C bar'1kg'1, about 1.55 kWh °C bar'1kg'1, about 1.67 kWh °C bar'1kg'1, about 1.90 kWh °C bar'1kg'1, about 2.04 kWh °C bar'1kg'1, about 2.18 kWh °C bar'1kg'1, about 2.20 kWh °C bar'1kg'1, about 2.22 kWh °C bar'1kg'1, about 2.33 kWh °C bar'1kg'1, about 2.34 kWh °C bar'1kg'1, about 2.35 kWh °C bar'1kg'1, about 2.38 kWh °C bar'1kg'1, about 2.87 kWh °C bar'1kg'1, about 2.93 kWh °C bar'1kg'1, about 3.02 kWh °C bar'1kg'1, about 3.61 kWh °C bar'1kg'1, about 3.65 kWh °C bar'1kg'1, and about 3.78 kWh °C bar'1kg'1.

[0122] In the preparation of TRES, it is preferred that the SME*T / P is in a range of from 0.25 to 5.00 kWh °C bar'1kg'1, and most preferably of from 0.30 to 4.34 kWh °C bar'1kg'1.

[0123] In the preparation of MOES, it is preferred that the SME*T / P is in a range of from 0.40 to 7.00 kWh °C bar'1kg'1, and most preferably of from 0.49 to 6.57 kWh °C bar'1kg'1.

[0124] As the skilled person is aware, some parameters, such as the throughput and the screw speed, may depend on the type of extruder and screws used. The skilled person is able to recalculate the values for these parameters for other types of extruder. For example, typically for a small extruder, the extruder can be operated at 100 - 1800 screw rotations per minute (rpm), preferably 200 - 1250 rpm, more preferably 250 - 750 rpm; alternatively, the extruder can preferably be operated at 250 - 1600 rpm. Higher rotation speeds, such as 500 - 1600 rpm, preferably 900 - 1500 rpm, provide for higher throughput and hence improved production efficiency. Likewise, also typical for a small extruder is a throughput of about 10-100 kg / h.

[0125] In a particularly favourable embodiment, the extrusion process is characterized by: (a) a degradation factor defined as SME*T / P in a range of from 0.05 to 10 kWh °C bar'1kg'1; (b) a T in a range of from 120 to 200 °C; (c) a P in a range of from 1 to 90 bar;

[0126] (d) an SME of at least 0.05 kWh / kg, preferably in a range of from 0.05 to 0.50 kWh / kg;

[0127] (e) a moisture content of the melt during extrusion in a range of from 10 to 50 wt%, as compared to the total weight of the melt; and / or (f) a torque in a range of from 15 to 75%. More preferably, at least conditions (a)-(e) are applied.

[0128] In another preferred embodiment, the extrusion process is characterized by: (a) a degradation factor defined as SME*T / P in a range of from 0.40 to 3.80 kWh °C bar'1kg'1; preferably of from 0.45 to 3.78 kWh °C bar'1kg'1; (b) a T in a range of from 170 to 200 °C; preferably of from 175 to 191 °C; (c) a P in a range of from 8 to 60 bar; preferably of from 10 to 56 bar; (d) a special mechanical energy (SME) in a range of from 0.140 to 0.230 kWh / kg; preferably of from 0.144 to 0.220 kWh / kg; and / or (e) a moisture content of the melt during extrusion in a range of from 18 to 25 wt%, preferably of from 20 to 22 wt%, as compared to the total weight of the melt; wherein SME (in kWh / kg) is the specific mechanical energy transferred from the extruder to the starting composition; P (in bar) is the pressure at the die of the extruder; and T (in °C) is the melt temperature at the die of the extruder. More preferably, all of conditions (a)-(e) are applied. In particular, the conditions (a)-(e) of this paragraph are preferred if the method is for providing LVES.

[0129] In another preferred embodiment, the extrusion process is characterized by: (a) a degradation factor defined as SME*T / P in a range of from 0.45 to 3.78 kWh °C bar'1kg'1; (b) a T in a range of from 175 to 191 °C; (c) a P in a range of from 10 to 56 bar; (d) a special mechanical energy (SME) in a range of from 0.144 to 0.220 kWh / kg; and / or (e) a moisture content of the melt during extrusion in a range of from 20 to 22 wt%, as compared to the total weight of the melt; wherein SME (in kWh / kg) is the specific mechanical energy transferred from the extruder to the starting composition; P (in bar) is the pressure at the die of the extruder; and T (in °C) is the melt temperature at the die of the extruder. More preferably, all of conditions (a)-(e) are applied. In particular, the conditions (a)-(e) of this paragraph are preferred if the method is for providing LVES.

[0130] In an exemplary embodiment, the extruder can be a ZSK 27 extruder (a co-rotating twin-screw extruder marketed by Coperion). In this particular embodiment, further described in the examples, the extruder comprises 6 blocks, having a total length of 24D. The diameter D of the screws is 27 mm. The barrel section, and thus the screws, have a total length of around 648 mm, and the screw diameter is 27 mm.

[0131] In this exemplary embodiment, the screw configuration comprises two reversed pitch elements alternatingly intertwined with conveying elements. The reversed pitch elements are preferably placed towards the end of the screw starting at position 18 D. The die section comprises two conical cavities, comprising cylindrically shaped die holes having a diameter of 3 mm and a length of 2 mm. In this particular embodiment, the temperature in the first (feeding) block and second (water addition) block can be more or less ambient. Preferably, the second block is operated at a temperature of from 25 to 65 °C, preferably of from 30 to 60 °C. Preferably, the third block is operated at a temperature of from 35 to 85 °C, preferably of from 40 to 80 °C. Preferably, the fourth block is operated at a temperature of from 85 to 105 °C, more preferably of from 90 to 100 °C. Preferably, the fifth block is operated at a temperature of from 115 to 145 °C, more preferably of from 120 to 140 °C. Preferably, the sixth block is operated at a temperature of from 135 to 165 °C, more preferably of from 140 to 160 °C. The throughput is 15 to 45 kg / h, preferably of from 25 to 35 kg / h, based on total weight (including moisture); and operated at 500 rpm. At higher rotation speed, the throughput can be higher, as the skilled person appreciates. The throughput can be 10 - 100 kg / h, preferably 15 - 80 kg / h. At 800 - 1600 rpm, the throughput can be 40 - 80 kg / h.

[0132] Obtaining the extrudate and further optional steps

[0133] In step (c) of the method of the invention, the extrudate is obtained. It will be understood that the extrudate is the extruded starch composition of the invention.

[0134] In principle, the extrudate can be used directly, without any further processing steps.

[0135] However, optionally the extrudate is dried. Suitable drying techniques are known in the art. In particular, the extrudate may be subjected to air drying (in particular hot-air drying), fluidized-bed drying, drum drying, microwave drying, vacuum drying, freeze drying, and / or infrared drying. Preferably, the extrudate is dried to a moisture content of at most 20 wt%, more preferably at most 15 wt%, more preferably at most 10 wt%, more preferably at most 5 wt%, more preferably at most 4 wt%, more preferably at most 3 wt%, more preferably at most 2 wt%, and most preferably at most 1 wt%, wherein the wt% is relative to the total weight of the extrudate.

[0136] Optionally, the extrudate is subjected to particle size reduction. The optional step of reducing the particle size of the extrudate may be performed before, after, and / or during the optional drying of the extrudate. Suitable techniques to reduce the particle size of starch compositions are known to the skilled person. In particular, the extrudate may be subjected to grinding, crushing, milling, sieving, screening, and / or high-shear blending. Preferably, the extrudate is subjected to hammer milling, pin milling, or ball milling; more preferably the extrudate is subjected to hammer milling.

[0137] Preferably, the method of the invention consists of steps (a), (b) and (c). However, in some embodiments, step (c) is followed by one or more subsequent processing step(s) of the extrudate.

[0138] Starch Compositions

[0139] The invention also pertains to an extruded starch composition obtainable by a method of the invention. As noted above, the extruded starch in said extruded starch composition may be LVES, TRES, and / or MOES. It is preferred that the extruded starch in the extruded starch composition of the invention is either LVES, TRES, or MOES.

[0140] For all embodiments, it is preferred that the extruded starch composition of the invention comprises at least 55 wt% of amylopectin, more preferably at least 60 wt%, more preferably at least 65 wt%, and most preferably at least 70 wt%. Preferably, the extruded starch composition of the invention comprises amylopectin in an amount in a range of from 55 to 99 wt%, more preferably from 60 to 98 wt%, more preferably from 65 to 97 wt%, and most preferably from 70 to 95 wt%.

[0141] For all embodiments, it is preferred that the extruded starch composition of the invention comprises at most 45 wt% of amylose, more preferably at most 40 wt%, more preferably at most 35 wt%, and most preferably at most 30 wt%. Preferably, the extruded starch composition of the invention comprises amylose in an amount in a range of from 1 to 45 wt%, more preferably from 2 to 40 wt%, more preferably from 3 to 35 wt%, and most preferably from 5 to 30 wt%.

[0142] For all embodiments, it is preferred that the extruded starch composition of the invention has a moisture content of at most 30 wt%, more preferably at most 25 wt%, more preferably at most 20 wt%, more preferably at most 15 wt%, more preferably at most 10 wt%, more preferably at most 5 wt%, more preferably at most 4 wt%, more preferably at most 3 wt%, more preferably at most 2 wt%, and most preferably at most 1 wt%, wherein the wt% is relative to the total weight of the extruded starch composition of the invention. In one embodiment, the extruded starch composition comprises at least a first starch mass fraction denoted as SMF1, a second starch mass fraction denoted as SMF2, and a third starch mass fraction denoted as SMF3, in which:(i) SMF1 has an Mw in a range of from 3850 to 13 000 kDa; preferably of from 3900 to 12850 kDa; (ii) SMF2 has an Mw in a range of from 1100 to 4700 kDa; preferably of from 1137 to 4645 kDa; (iii) SMF3 has an Mw in a range of from 320 to 4500 kDa; preferably of from 355 to 4403 kDa; (iv) the extruded starch composition has an Mw in a range of from 1300 to 10 000 kDa; preferably of from 1477 to 9216 kDa; and (v) the dispersity of the extruded starch composition has a value in a range of from 0.75 to 1.9; preferably of from 0.79 to 1.8; and wherein the Mw of SMF1 is different from the Mw of SMF2 and different from the Mw of SMF3; the Mw of SMF2 is different from the Mw of SMF3; and wherein Mw denotes the weight average molecular weight. Preferably, the composition also comprises a fourth starch mass fraction denoted as SMF4, wherein the Mw of SMF4 is different from the Mw of SMF1, different from the Mw of SMF2, and different from the Mw of SMF3; wherein the Mw of SMF4 is in a range of from 1400 to 10000 kDa, preferably of from 1473 to 9189 kDa. This embodiment may relate to the composition per se or to the composition as obtainable by a method of the invention. Preferably, the extruded starch composition of this embodiment is a low-viscosity extruded starch (LVES) composition. Preferably, the combined weights of SMF1, SMF2, and SMF3 constitute at least 50 wt% of the dry weight of the extruded starch composition, more preferably at least 60 wt%, even more preferably at least 70 wt%, more preferably at least 75 wt%, more preferably at least 80 wt%, more preferably at least 85 wt%, more preferably at least 90 wt%, more preferably at least 95 wt%, more preferably at least 97 wt%, and most preferably at least 99 wt%, wherein the wt% is as compared to the dry weight of the extruded starch composition. If SMF4 is present, it is preferred that the combined weights of SMF1, SMF2, SMF3, and SMF4 constitute at least 50 wt% of the dry weight of the extruded starch composition, more preferably at least 60 wt%, even more preferably at least 70 wt%, more preferably at least 75 wt%, more preferably at least 80 wt%, more preferably at least 85 wt%, more preferably at least 90 wt%, more preferably at least 95 wt%, more preferably at least 97 wt%, and most preferably at least 99 wt%, wherein the wt% is as compared to the dry weight of the extruded starch composition.

[0143] As used herein in relation to LVES, “low-viscosity” typically means that the viscosity of the extruded starch is lower than that of the native granular starch from which said extruded starch is obtained. Preferably, “low-viscosity” means that the viscosity of the extruded starch is at most 1000 mPa*s, more preferably at most 900 mPa*s, more preferably at most 800 mPa*s, more preferably at most 750 mPa*s, more preferably at most 700 mPa*s, more preferably at most 650 mPa*s, and most preferably at most 625 mPa*s. Preferably, “low-viscosity” means that the viscosity of the extruded starch is in a range of from 10 to 1000 mPa*s, more preferably from 50 to 900 mPa*s, more preferably from 100 to 800 mPa*s, more preferably from 200 to 750 mPa*s, more preferably from 250 to 700 mPa*s, more preferably from 290 to 650 mPa*s, and most preferably from 310 to 625 mPa*s. Preferably, the viscosity as mentioned in this paragraph is determined by the method of Example 2C, and is preferably the end viscosity as determined in said method of Example 2C.

[0144] In another embodiment, the extruded starch composition is an LVES composition having a viscosity in a range of from 200 to 750 mPa*s, more preferably from 250 to 700 mPa*s, more preferably from 290 to 650 mPa*s, and most preferably from 310 to 625 mPa*s; wherein preferably, the viscosity as mentioned in this paragraph is determined by the method of Example 2C, and is preferably the end viscosity as determined in said method of Example 2C. This embodiment may relate to the composition per se or to the composition as obtainable by a method of the invention.

[0145] For MOES, it is preferred that the modified starch is selected from the group consisting of crosslinked starch, esterified starch, etherified starch, oxidized starch, hydrolyzed starch, phosphorylated starch, grafted starch, and combinations thereof. In this respect, it will be understood that “combinations thereof’ refers to modified starch having been modified in more than one way, for example crosslinked and phosphorylated starch.

[0146] Most preferably, the modified starch is crosslinked starch. Preferably, the crosslinked starch is crosslinked by one or more crosslinkers selected from the group consisting of citric acid, trimetaphosphate, epichlorohydrin, phosphorus oxychloride (POCE), tripolyphosphate, anhydride, and pyrophosphate; more preferably the one or more crosslinkers are selected from the group consisting of citric acid, and trimetaphosphate. Preferably, the anhydride is adipic anhydride. Preferably, the modified starch composition has a viscosity in a range of from 500 to 3000 cP, more preferably from 700 to 2400 cP, more preferably from 720 to 2300 cP, most preferably from 750 to 2250 cP. Exemplary values for the peak viscosity include about 1295 cP, about 1146 cP, about 888 cP, about 1238 cP, about 786 cP, about 1029 cP, about 1369 cP, about 2235 cP, about 2213 cP, about 1960 cP, about 2121 cP, about 1893 cP, and about 1745 cP. Preferably, the viscosity is the end viscosity measured according to the procedure described in Example 4A.3.

[0147] For TRES, it is preferred that the thermoreversible gelling starch is also cold-water soluble. Herein, “cold water soluble” or “cold-water soluble” means that the composition readily dissolves in water of ambient temperature, viz. of about 15-25 °C. Preferably, a cold-water soluble composition has a solubility of at least 0.01 wt% in water of 25 °C, more preferably a solubility in a range of from 0.01 to 35 wt% in water of 25 °C, wherein preferably the water is demineralized water. Herein, “cold-water soluble” may be used interchangeably with “cold-water swellable”. Preferably, a cold- water swellable composition does not form a precipitate if the composition is present in water of 25 °C at a concentration of at least 0.01 wt%, preferably of from 0.01 to 35 wt%, as compared to the combined weight of the water and the composition, wherein preferably the water is demineralized water.

[0148] In one embodiment, the composition of the invention is an extruded starch composition is a cold-water soluble thermoreversible gelling starch composition comprising at least two starch mass fractions Mwl and Mw2, in which a) starch mass fraction Mwl has a weight average molecular weight in a range of from 13 000 to 35 000 kDa; preferably of from 17 000 to 32 000 kDa; b) starch mass fraction Mw2 has a weight average molecular weight in a range of from 700 to 3000 kDa; preferably of from 750 to 2500 kDa; c) the sum of the starch mass fractions Mwl and Mw2 represents at least 50 wt.% of the total weight of the cold-water soluble thermoreversible gelling starch composition; and d) the mass ratio between the starch mass fractions Mwl and Mw2 is in a range of from 1.1 : 1 to 20 : 1. This embodiment may relate to the composition per se or to the composition as obtainable by a method of the invention. Further products and applications

[0149] An extruded starch composition as provided herein has unique properties that make it suitable for specialized food and non-food applications. Extruded starch compositions of the invention have a wide range of applications due to the various types of extruded starch that can be obtained. Extruded starch compositions are particularly useful in food products (instant foods, desserts, sauces), pharmaceuticals (drug delivery, for example capsules), cosmetics (creams, gels), and industrial uses (adhesives, textiles, and packaging). The possible variations in modification allow for flexibility in product formulation, easy processing, and enhanced consumer convenience.

[0150] The invention therefore also relates to a consumer product or an industrial product comprising an extruded starch composition according to the invention. For example, provided herein is a food item, a feed item, a thickening agent, an adhesive, a cosmetic product, paper, or a construction material, comprising an extruded starch composition according to the invention. Furthermore, the invention relates to the use of an extruded starch composition according to the invention as a food ingredient, a feed ingredient, a thickening agent, and / or an adhesive agent. Also provided is the use of an extruded starch composition of the invention as an ingredient for a cosmetic product, a gelling agent, a pectin replacer, a gelatin replacer, as an ingredient for the production of paper, and / or as a component of a construction material.

[0151] In one embodiment, the invention provides the use of an extruded starch composition in the food industry, for example in instant or no-cook food items. Also provided is a food item comprising an extruded starch composition. For example, it is ideal for applications like instant puddings or desserts, or in cold-prepared salad dressings and dips. Other applications include instant soups and sauces, and bakery fillings and glazes.

[0152] In a specific aspect, the extruded starch composition of the invention is used in a confectionery product. Alternatively, extruded starch compositions of the invention can improve texture and stability in frozen desserts like ice cream or frozen yogurts by creating a stable, creamy consistency. Still further food applications include meat and fish products. In one embodiment, the invention provides the use of an extruded starch composition of the invention as a food ingredient, thickening agent, and / or (vegan) gelatin replacer. Furthermore, extruded starch compositions of the invention can be used in dairy products, such as yogurt.

[0153] As there is also a strong desire to provide more plant-based products, especially from an environmental perspective, it is an additional advantage of products of the invention that these can in principle be plant-based (i.e. vegan).

[0154] Also envisaged are pharmaceutical and nutraceutical applications. In one embodiment, an extruded starch composition of the invention is used in a drug delivery systems or a topical gel.

[0155] As such, the disclosure also relates to extruded starch compositions of the invention for use as a medicament. Furthermore, the disclosure pertains to a method of treating a subject, said method comprising the step of administering an extruded starch composition of the invention to said subject. Additionally, the disclosure relates to the use of an extruded starch composition of the invention in the manufacture of a medicament for the treatment of a disease in a subject.

[0156] Still further, the composition of the invention finds its use in a nutritional supplement where a thickened gel consistency enhances mouthfeel or helps with ease of ingestion, like instant meal replacements or protein gels. Extruded starch compositions of the invention can provide smooth, spreadable textures for skincare products. Other products that can benefit from including an extruded starch composition as provided herein include cosmetics and personal care products, such as lotions, creams, hair gels and styling products.

[0157] Extruded starch compositions of the invention also have a range of industrial applications. Extruded starches can be used in adhesives. These starches can furthermore be used in textile processing, especially in warp sizing (coating of yarns). Extruded starch compositions of the invention can improve the strength, flexibility, and resilience of paper products and biodegradable packaging materials, especially those that require moisture resistance. Finally, the extruded starch compositions of the invention can also be used in construction.

[0158] Further definitions

[0159] Unless indicated otherwise, “wt%” as used herein refers to the weight percentage as compared to the dry weight of the relevant composition. Unless indicated otherwise, “average molecular weight” as used herein refers to the weight average molecular weight.

[0160] Unless indicated otherwise, “extrusion barrel” and “extruder barrel” are herein used interchangeably.

[0161] As used herein, “about” preferably means a deviation of at most 10% of the given value, more preferably at most 7.5%, more preferably at most 5%, even more preferably at most 2.5%, and most preferably at most 1%.

[0162] EXAMPLES

[0163] The invention is illustrated below using several examples. It will be understood that the invention is not limited thereto, and other embodiments such as those listed above are also capable of achieving the technical effects and benefits of the invention. In particular, the starting materials and extrusion conditions used in the examples are not limiting, and the specification indicates other suitable materials and conditions.

[0164] Example 1 provides general information on the equipment and settings used in the extrusion experiments (viz. Examples 2A, 3A, and 4A).

[0165] Examples 2A-2C relate to the provision and characterization of low-viscosity extruded starch (LVES).

[0166] Examples 3A-3D relate to the provision, characterization, and application of cold- water soluble thermoreversible gelling extruded starch (TRES).

[0167] Examples 4A and 4B relate to the provision and characterization of modified extruded starch (MOES). Example 4A relates to obtaining MOES from native potato starch and citric acid. Example 4B relates to obtaining MOES from native potato starch or native faba starch in the presence of sodium trimetaphosphate (STMP).

[0168] Example 1 - General equipment and settings for obtaining extruded starch

[0169] Equipment used in Examples 2A, 3A, and 4A

[0170] A ZSK27 Coperion twin-screw, co-rotating, self-wiping extruder was used which had three peripherals attached to it: a water pump gravimetric feeder (Feeder 1), a solid material gravimetric feeder (Feeder 2) and a centric pelletizer (1 or 3 blades) provided with a compressed air outlet. The extruder barrel was composed of 6 modular blocks having a total length of 24D (4D x 6). The diameter D of the screws was 27 mm. The screws, had a total length of around 648 mm. For all samples of Examples 2A, 3A, and 4A presented below, apart from samples 13 and 14 in Table 17 below, the die plate used presented conical cavities that ended into cylindrical die holes having a diameter of 3 mm and a length of 2 mm. For samples 13 and 14 in Table 17 below, the die plate used presented one conical cavity that ended into a cylindrical die hole having a diameter of 3 mm and a length of 2 mm. The die configurations were indicated as nx(DxL), where n stands for the total number of holes, D stands for the Diameter of the holes and L stands for the Length of the holes. The solids were fed at 2D, the water inlet was placed at 9D. The pelletizer blades distance to the die was set as close to the die holes as possible ( <

[0171] 1 mm). Extrudates were milled to the required particle size with a hammer-mill over selected sieves (1 and 0.5 mm). Detailed information regarding equipment used is available in Table 1 below. Table 1. Equipment used for extrusion and milling. The screw configuration designs used were as described in Table 2 (configuration S. l), Table 3 (configuration S.2), Table 4 (configuration S.3), Table 5 (configuration S.4), Table 6 (configuration S.5), and Table 7 (configuration S.6). In said Tables C stands for Conveying, K45 stands for Kneading at 45° stagger angle, P stands for Positively conveying elements, N stands for Negatively conveying elements and all elements were defined with element length over pitch length eL / pL. At 18.89D (or 510 mm) S. l has a CP while S.2 has a CN. So, S.l has 1 negative element and S.2 has 2 negative elements. Thus, S.2 applies more shear / rpm. Table 2. Screw configuration design S.l. Table 3. Screw configuration design S.2.

[0172] Table 4. Screw configuration design S.3.

[0173] Table 5. Screw configuration design S.4.

[0174] Table 6. Screw configuration design S.5.

[0175] Table 7. Screw configuration design S.6.

[0176] Example 2A - Obtaining low-viscosity extruded starch (LVES)

[0177] This Example describes how to obtain low-viscosity extruded starch (LVES) compositions. The temperature (T) profile of the barrel block was set as shown in Table 8 below. The temperature of block 1 (feeding block) was not controlled, and is hence indicated with “NA” in Table 8. Blocks 2 to 6 were controlled via automatic electrical heating and water cooling. Table 8. Temperature settings of the barrel blocks.

[0178] The native granular starch that is subjected to extrusion in this Example is indicated in Table 9. Table 9. Starch used in exemplary starting compositions for the LVES experiments.

[0179] Extrusion procedure

[0180] Untreated and unmodified raw materials (NPS) and drinkable water were fed to the extruder and thermomechanically processed accordingly to the settings indicated in Table 10. Therein, SME (kWh / kg) is the specific mechanical energy transferred from the extruder to the starting composition, P (bar) is the pressure at the die of the extruder, T (°C) is the melt temperature at the die of the extruder, and the moisture content refers to the water content of the melt during extrusion as compared to the total weight of said melt. In all LVES experiments, a 2x(3x2) die configuration was used.

[0181] The resulting pelletized extrudates (with 1 blade at 2000 rpm) were collected and stored on metal plates to let them cool down and release excess moisture overnight. The following day, extrudates were hammer milled in two steps (through 1 mm and 0.5 mm sieves, at 3.5 rotational speed setting).

[0182] Table 10. Extrusion settings used for obtaining LVES in experiments 132-158.

[0183]

[0184] *Screw configurations S.3, S.4. and S.5 are shown in Tables 4, 5, and 6, respectively.

[0185] Example 2B - Molecular weight analysis of low-viscosity extruded starch (LVES)

[0186] Samples 132-158 obtained in Example 2A were subjected to molecular weight analysis.

[0187] Molecular weight analyses were performed by size exclusion chromatography (SEC) with multi-angle laser light scattering (MALLS) and refractive index detection (RI). Shodex-OHpakSB-803 HQ column was used with 50 nM NaNCh as eluent. Detection was performed with a multiangle laser light scattering photometer (type Dawn Heleos II, 18 angles, Wyatt Technology) with a refractive index detector (Optilab T-rEx-658 nm, Wyatt Technology). Data were evaluated by the Berry equation method, second order fit and second virial coefficient (A2=0). The refractive index increment dn / dc was 0.148 ml / g and these measurements were performed at 25 °C.

[0188] A specific amount (~50 mg) of a sample (powder, as is) was dissolved with a 20 ml of eluent (50 nM NaNCh) at 130°C for 60 minutes. The sample were continuously stirred in a glass vial and the vial was capped with an aluminum / silicone septum. The solution was filtered through 0.45 gm cellulose acetate filter before injection on the SEC.

[0189] The results are shown in Table 11 below. Therein, the average molecular weight refers to the weight average molecular weight. Typically, four mass fractions were obtained, although for samples 139 and 157 only three mass fractions were observed.

[0190] As a reference, the weight average molecular weight (Mw avg.) of the raw material (viz. NPS) was 443 847 kDa.

[0191] Table 11. Results from molecular weight analyses of extrudates 132-158 obtained in Example 2A. Mwi denotes the weight average molecular weight of the first mass fraction; Mw2 denotes the weight average molecular weight of the second mass fraction; Mws denotes the weight average molecular weight of the third mass fraction; Mw4 denotes the weight average molecular weight of the fourth mass fraction; MW OT denotes the weight average molecular weight of the total composition; and DHTOT denotes the polydispersity of the total composition. N / A denotes “not applicable ”, because the sample did not contain a fourth mass fraction.

[0192] Example 2C - Viscosity measurements of low-viscosity extruded starch (EVES)

[0193] The viscosity of the extrudates samples 132-158 as obtained in Example 2A was determined with a rapid visco-analyzer (RVA Super 4 Newport Scientific (serial no. 2041657). Aqueous solutions of said extrudates were separately prepared using demineralized water to obtain a dry matter content of 15 wt% based on the total weight of the solution. The settings for the RVA method are described in Table 12 below.

[0194] Table 12. Settings for the rapid visco-analyzer analyzing the extrudates of Example 2A.

[0195] During the measurement, the viscosity increases until it reaches a plateau. The final viscosities of samples 132-158 are shown in Table 13. Table 13. End viscosities measured for the extrudates of Example 2A.

[0196] Example 3A - Obtaining thermoreversible gelling extruded starch (TRES)

[0197] This Example describes how to obtain cold-water soluble thermoreversible gelling extruded starch (TRES) compositions.

[0198] Barrel block settings and starting materials

[0199] The temperature (T) profile of the barrel block was set as shown in Table 14 below, with set temperature profile I used for samples 1-12 of Table 16 below, and set temperature profile II for samples 13 and 14 of Table 16. The temperature of block 1 (feeding block) was not controlled, and is hence indicated with “NA” in Table 14. For both set temperature profiles, blocks 2 to 6 were controlled via automatic electrical heating and water cooling.

[0200] Table 14. Temperature settings of the barrel blocks in the TRES experiments.

[0201] The native granular starches that are subjected to extrusion in this Example are indicated in Table 15.

[0202] Table 15. Native granular starches used in the TRES experiments.

[0203] Extrusion procedure

[0204] Untreated and unmodified raw starch materials (WPS, WTS, NFS, NPES) and drinkable water were fed to the extruder and thermomechanically processed accordingly to the settings indicated in Table 16. Therein, SME (kWh / kg) is the specific mechanical energy transferred from the extruder to the starting composition, P (bar) is the pressure at the die of the extruder, T (°C) is the melt temperature at the die of the extruder, and the moisture content refers to the water content of the melt during extrusion as compared to the total weight of said melt.

[0205] The resulting pelletized extrudates (with 1 blade at 3000 rpm) were collected and stored on metal plates to let them cool down and release excess moisture overnight. The following day, extrudates were hammer milled in two steps (through 1 mm and 0.5 mm sieves, at 3.5 rotational speed setting). Samples 9 and 10 were performed with Rose Brand WTS, and samples 1-8, 11, and 12 were performed with Avebe WPS.

[0206] Table 16. Native granular starches and extrusion settings used for TRES experiments 1- 14.

[0207] *A = lx(3x2), S.2; B = 2x(3x2), S.2; C = 2x(3x2), S.l; D = lx(3x2), S.6.

[0208] Example 3B - Molecular weight analysis of thermoreversible gelling extruded starch (TRES)

[0209] Extrudates 1-14 as obtained in Example 3A were analyzed as described below. The results of these analyses are shown in Table 17 (extrudates 1-12) and Table 18 (extrudates 13 and 14) below. Therein, the average molecular weight (Mw) refers to the weight average molecular weight and Dn refers to the polydispersity. Unless reference is made to mass fraction 1 (Fxl), mass fraction 2 (Fx2), or mass fraction 3 (Fx3), the average values provided in Tables 17 and 18 relate to the extrudate as a whole.

[0210] As a reference, the average molecular weights (Mw avg.) of raw materials were 100 223 kDa for WPS; 270 000 kDa for WTS; 152 000 kDa for NFS; and 328 000 kDa for NPES. Example 3B.1 - Analysis of extrudates 1-12

[0211] Extrudates 1-12 obtained in Example 3A were subjected to molecular weight analysis. Molecular weight analyses were performed by size exclusion chromatography (SEC) with multi-angle laser light scattering (MALLS) and refractive index detection (RI). A Shodex-OHpakSB-804 HQ column was used with 50 nM NaNCh as eluent. Detection was performed with a multiangle laser light scattering photometer (type Dawn Heleos II, 18 angles, Wyatt Technology) with a refractive index detector (Optilab T-rEx-658 nm, Wyatt Technology). Data were evaluated by the Berry equation method, second order fit and second virial coefficient (A2=0). The refractive index increment dn / dc was 0.148 ml / g and these measurements were performed at 25 °C.

[0212] A specific amount (~60 mg) of a sample (powder, as is) was dissolved with a 20 ml of eluent (50 nM NaNCh) at 130°C for 20 minutes. The sample was continuously stirred in a glass vial and the vial was capped with an aluminum / silicone septum. The solution was filtered through 5.0 pm cellulose acetate filter before injection on the SEC.

[0213] Table 17. Results from molecular weight analyses of extrudates 1-12 obtained in Example 3 A.

[0214] Example 3B.2 - Analysis of extrudates 13 and 14

[0215] For extrudates 13 and 14 as obtained in Example 3 A, analyses were performed using Asymmetric Flow Field Flow Fractionation with Multi-Angle Laser Light Scattering and Refractive Index Detection (FFF(AF4) / MALLS / RI) and Size Exclusion Chromatography (SEC). The Eclipse AF4 system was equipped with a frit inlet channel (FI) and regenerated cellulose with a pore size of lOkDa (LOxlO4g / mol). Molecules with a molecular mass smaller than lOkDa (including salts) are washed away over the membrane. Elution was performed using a 50 mM NaNCh (aq) eluent. The Shodex OHpak SB-804 HQ SEC column was used. This column can separate molecules with a molecular weight ranging from 5xl03to IxlO6Da. Detection was performed using a multi-angle laser light scattering photometer (Dawn Heleos II, 18 angles, Wyatt Technology) and a refractive index detector (Optilab T-rEx, 658 nm, Wyatt Technology). The data were evaluated using the Berry equation method with a second- order fit and a second-virial coefficient of A2 = 0. The refractive index increment, dn / dc, was 0.148 ml / g, and these measurements were performed at 25 °C.

[0216] A specific amount (50 mg) of a defatted sample (powder (as is)) was dissolved with a 20 ml of eluent (50 mM NaNCh) at 130°C for 30 minutes. The sample was continuously stirring in a glass vial and the vial was capped with an aluminum / silicone septum. The solution was filtered through 5.0 pm cellulose acetate filter before injection on the FFF / SEC. Table 18. Results from molecular weight analysis of extrudates 13 and 14.

[0217] Example 3C - Thermoreversible gelling using TRES

[0218] Example 3C.1 - thermoreversible gelling of extrudates 1-12 of Example 3 A

[0219] The extrudates 1-12 obtained in Example 3A were evaluated for thermoreversibility by preparing gels and treating them with multiple steps of heating and cooling. To that end, solutions at 15% and 35% w / w in demineralized water were prepared by stirring at room temperature and were then heated to boiling in a water bath for 5-10 minutes. The solutions were then stored overnight in a fridge at 4-7 °C. The formed gels were then reheated on a water bath for 5 to 10 minutes and loss of viscosity was observed until transparent viscous liquid-like gels to thin liquid-like gels were observed. A cooling step was then repeated overnight in the fridge and solid gels could be observed the day after.

[0220] Rheology tests were performed on a selection of samples, especially with the aim to compare WPS- and WTS-based TRES gels. Gels at 25% w / w in demineralized water of TRES samples (1, 6, 10, 12) were prepared by stirring for 5-10 minutes. The weight of the extrudate powder was calculated based on the powder moisture content. The total mass of the solution was set to be 25 grams. Subsequently, the suspension was stirred and heated until boiling in a water bath for approximately 10 minutes. The solution thus obtained was then poured into a capped container and stored in the fridge at 4-7°C overnight to form a solid gel to be tested on a rheometer.

[0221] Rheological measurements were executed with a 50 mm parallel plate geometry at a gap of 1000 pm in the Anton Paar Rheometer (MCR-302) from RheoCompass (Austria, Europe). Samples were loaded onto the rheometer plate and excess sample was removed using a spatula. Paraffin oil was used to prevent evaporation during the measurement. The experiments were carried out at a heating rate of 5°C / min. Strain for the measurements at 1% is selected to ascertain the thermal equilibration of the samples and to be within the linear viscoelastic (LVE) region. Dynamic temperature sweeps (40- 90 °C) were performed at a fitting strain rate and angular frequency (1 rad / s) to investigate the effect of temperature on storage modulus (G') and loss modulus (G") of the material.

[0222] Variations in absolute values of viscosity plus an inversion of the G’ and G” between 45 to 75 °C (with observable shift of melting point) were observed for all the samples tested. See Figure 1 for exemplary extrudates 1, 7 and 12. These results confirmed already observed thermoreversibility and indicates that extrusion conditions and molecular weight influenced gel strength (viscosity both at low and high temperature) and melting point.

[0223] Example 3C.2 - Thermoreversible sellins of extrudates 13 and 14 of Example 3 A

[0224] The thermoreversible gelling properties of the extrudates samples 13 and 14 as obtained in Example 3 A were determined with a rapid visco-analyzer (RVA Super 4 Newport Scientific (serial no. 2041657). Aqueous solutions of extrudates 13 and 14 were separately prepared using demineralized water to obtain a dry matter content of 15 wt% based on the total weight of the solution. The settings for the RVA method are described in Table 19 below. In these analyses, two consecutive cycles of a temperature scan were performed to check on thermoreversibility. The results are shown in Table 20.

[0225] Table 19. Settings for the rapid visco-analyzer analyzing extrudates 13 and 14..

[0226] Table 20. Results of the rapid visco-analyzer analyses of extrudates 13 and 14..

[0227] Note: An increase of viscosity is observed from 1stto 2ndcycle, which can be attributed to an increase in sample concentration due to water evaporation, being the RVA cups used open to air.

[0228] Example 3D - Cold water solubility and application of TRES in panna cotta

[0229] The extrudates obtained in Example 3 A showed quick cold water solubility, instantly dissolving in water at room temperature (20-25 °C) while stirring, both in demineralized and drinking water, forming clear solutions. Extrudates 1-12 were tested at concentrations between 5% to 35% w / w, and extrudates 13 and 14 at 15% w / w. All tested concentrations gave the desired result of quick cold water solubility.

[0230] To demonstrate one of the many possible applications of the extrudates obtained in Example 3A, extrudates 1-12 were used to prepare panna cotta. In particular, the aim was to reproduce the gelling behavior of classic gelatin by using an extrudate obtained in Example 3 A. The ingredients are shown in Table 21.

[0231] Table 21. Ingredients used for making panna cotta. Panna Cotta preparation with classic gelatin requires soaking of gelatin and heating while mixing with other ingredients. To prepare a one-to-one comparison, soy whipping cream, sugar and an extrudate obtained in Example 3 A were mixed in the amounts shown in Table 21. Mixing was performed at room temperature (about 20-25 °C). A homogenous mix was easily obtained at room temperature without formation of lumps for all extrudates used. The mix was subsequently heated to boiling while stirring (in a 100 ml beaker in a water bath, constantly stirred at 600-800 rpm with a magnetic stirrer). The mix was then poured into a small plastic container which was sealed with a lid and stored in a fridge overnight at 4-7 °C. Texture of the gels was then visually checked and tested by scooping the gels with a tea spoon.

[0232] A variety of textures was obtained, as shown in Table 22 below. The meaning of the quality score in Table 22 is shown in Table 23.

[0233] Table 22. Results from the panna cotta tests using extrudates 1-12 obtained in Example 3A. The third column provides a value for the degradation factor divided by the average polydispersity of the extrudate. Table 23. Scoring method used to assign the score provided in Table 22.

[0234] Based on extrusion conditions, it was possible to obtain a variety of textures (smooth firm gels, smooth soft gels, irregular soft gels). In particular, a correlation between extrusion conditions and firmness could be observed. While firm and smooth gels are preferred for panna cotta, gels with other textures and / or surfaces (i.e. having a lower score in Table 22) find their use in other applications such as, but not limited to, the preparation of ricotta cheese, yoghurt, creams, custards, and the like.

[0235] Example 4A - Obtaining modified extruded starch (MOES) with native potato starch and citric acid

[0236] This Example describes how to obtain modified extruded starch (MOES) compositions using native potato starch and citric acid.

[0237] Example 4A.1 - Barrel block settings and starting materials

[0238] The temperature (T) profile of the barrel block was set as shown in Table 24 below. The temperature of block 1 (feeding block) was not controlled, and is hence indicated with “NA” in Table 20. Blocks 2 to 6 were controlled via automatic electrical heating and water cooling.

[0239] Table 24. Temperature settings of the barrel blocks as used in Example 4A.

[0240] The materials subjected to extrusion in Example 4A are indicated in Table 25. Table 25. Compounds used in the MOES experiments for Example 4A. Other starches are also suitable.

[0241] Example 4 A.2 - Extrusion procedure

[0242] Citric acid (CA) was milled to reduce particle size before blending with NPS (for 1 :30 mm:ss at 3000 rpm, with intervals of 00: 15 mm:ss). Different blends of NPS and milled CA were prepared by physically blending the components in a tumbler mixer for 2 hours (15-20 kg total mass). In each experiment, apart from examples 8-11, a blend of NPS and milled CA, and water were fed to the extruder and processed accordingly to the settings available in the following table. In case of the examples 8-11, only NPS and water were fed to the extruder. As such, examples 8-11 do not relate to MOES as no starch-modifying agent was used. The resulting pelletized extrudates (with 1 blade at 1000 rpm) were collected and stored on metal plates to let them cool down and release excess moisture overnight. The following day, extrudates were hammer milled in two steps (through 1 mm and 0.5 mm sieves, at 3.5 rotational speed setting). For all trials, screw speed of 500 rpm, throughput of 30 kg / h, S.2 screw configuration of Table 3, and a 2x(3x2) die configuration were used. The conditions per experiment are shown in Table 26.

[0243] Table 26. Concentrations of citric acid and extrusion settings used in MOES experiments of Example 4 A. Samples 8-11 do not relate to MOES, as no modifying agent is used.

[0244]

[0245] Example 4 A.3 Viscosity analysis of modified extruded starch (MOES) of Example 4A.2

[0246] The viscosity of the extrudates of Example 4A.2 was determined with a rapid visco- analyzer (RVA Super 4 Newport Scientific (serial no. 2041657). First, a solution of the extrudate was prepared using demineralized water at room temperature, wherein the solution had a dry matter content of 16.67 wt% based on the total weight of the solution. Then, the viscosity of the solution was measured using the settings described in Table 27 below.

[0247] Table 27. Settings for the rapid visco-analyzer analyzing the extrudates of Example 4A.2.

[0248] Final viscosities of extrudates 4-20 were obtained, and are presented in Table 28 below.

[0249] Table 28. Peak viscosities measured for the extrudates of Example 4A.2.

[0250] Example 4B - Obtaining modified extruded starch (MOES) from native potato starch or native faba starch in the presence of sodium trimetaphosphate (STMP) Example 4B.1 - Equipment

[0251] A Process 11 Hygenic Thermo Fisher twin-screw, co-rotating, self-wiping extruder was used which had three peripherals attached to it: two water pumps and a solid material gravimetric feeder. The extruder barrel was composed of 8 modular blocks having a total length of 40D. The diameter D of the screws was 11 mm. The screws had a total length of around 440 mm. The die plate used presented one conical cavity that ended into a cylindrical die hole having a diameter of 2 mm and a length of 2,5 mm. The die configuration was indicated as nx(DxL), where n stands for the total number of holes, D stands for the Diameter of the holes and L stands for the Length of the holes. The solids were fed at 16D, the water inlet was placed at 21D. Extrudates were milled to a reduced coarse particle size. Detailed information regarding equipment used is available in Table 29 below. Table 29. Equipment used for extrusion and milling in Example 4B.

[0252] The screw configuration designs used in Example 4B were as described in Tables 30 and 31 (wherein C stands for Conveying, K45 stands for Kneading at 45° stagger angle, P stands for Positively conveying elements, N stands for Negatively conveying. “Ch. (#)” column refers to the amount of channels present on each element type.

[0253] Table 30. Screw configuration design S.7.

[0254]

[0255] Table 31. Screw configuration design S.8.

[0256] Example 4B.2 - Barrel block settings and starting materials

[0257] The temperature (T) profile of the barrel block was set as shown in Table 32 below. The temperature of block 1 (feeding block) was not controlled, and is hence indicated with “NA” in Table 32. Blocks 2 to 8 and the die insert were controlled via automatic electrical heating and water cooling.

[0258] Table 32. Temperature settings of the barrel blocks as used in Example 4B. The materials subjected to extrusion in Example 4B are indicated in Table 33.

[0259] Table 33. Components used in exemplary starting compositions for Example 4B.

[0260] Example 4B.3 - Extrusion procedure Sodium trimetaphosphate (STMP) solutions were prepared to be used as liquid feed for extrusion trials by stirring on a stirring plate at room temperature. The solutions were prepared immediately before starting extrusion trials. NPS and NFS were fed to the extruder and processed accordingly to the settings available in Table 35. The resulting extrudates were collected and stored on metal plates to let them cool down and release excess moisture overnight. The following day, extrudates were milled to a reduced coarse particle size. Sample 21 and sample 22 were based on NFS. Sample 23 and sample 24 were based on NPS. The STMP concentration refers to the starch dry matter quantity. Solutions of STMP in water were prepared accordingly.

[0261] Table 34. Starting materials, concentrations of STMP, and screw configurations used in Example 4B. Experiments 21 and 24 are not related to MOES, since no modifying agent was used.

[0262] Table 35. Extrusion settings used in Example 4B. Experiments 21 and 24 are not related to MOES, since no modifying agent was used.

[0263] Example 4B.4 RVA viscosity analysis of samples 21 and 22

[0264] The viscosity of the extrudates of sample 21 and sample 22 of Example 2.3 was determined with a rapid visco-analyzer (RVA Super 4 Newport Scientific (serial no. 2041657). First, a solution of the extrudate was prepared using demineralized water at room temperature, wherein the solution had a dry matter content of 14.66 wt% based on the total weight of the solution. Then, the viscosity of the solution was measured using the settings described in Table 14 below.

[0265] For sample 21, the viscosity at the end of the procedure described in Table 36 was 2820 mPa.

[0266] For sample 22, the viscosity at the end of the procedure described in Table 36 was 4607 mPa. Table 36. Settings for the rapid visco-analyzer analyzing extrudates 21 and 22 of Example 4B.3.

[0267] Example 4B.5 - Rheolab viscosity analysis of samples 23, and 24

[0268] The Rheolab viscosity analyses on the final products of sample 23 and sample 24 as obtained in Example 4B.3 were performed using the Anton Paar analyzer including spindle ST34-2D / 2V. Aqueous solutions of sample 23 and sample 24 were prepared using demineralized water, to obtain a dry matter content of 20 wt% based on the total weight of the solution. The settings used for the Anton Paar analyzer are described in Table 37 below.

[0269] For sample 23, the viscosity at the end of the procedure described in Table 37 was 1105 mPa.

[0270] For reference sample 24, the viscosity at the end of the procedure described in Table 37 was 1649 mPa.

[0271] Table 37. Settings for the Anton Paar analyzer analyzing extrudates 23 and 24 of Example 4B.3.

Claims

Claims1. A method for providing an extruded starch composition, wherein the method comprises the steps of:(a) providing a starting composition of a native granular starch, wherein the starting composition has a moisture content in a range of from 15 to 35 wt.% relative to the total weight of the starting composition, and wherein said native granular starch has not been subjected to any pretreatment; preferably the starting composition is free of any non-starch additives; more preferably the starting composition is free of any additives;(b) subjecting the starting composition to thermomechanical degradation by an extrusion process in an extruder barrel; and(c) obtaining and optionally drying the extrudate and / or subjecting the extrudate to a step of particle size reduction; wherein preferably the extrusion process is a single-step extrusion process.

2. The method according to claim 1, wherein the only substances provided to the extruder barrel during the extrusion process are the native granular starch, water, and optionally at least one starch-modifying agent.

3. The method according to any one of the preceding claims, wherein the only substances provided to the extruder barrel during the extrusion process are the native granular starch and water.

4. The method according to any one of the preceding claims, wherein the extrusion process is characterized by:(a) a degradation factor defined as SME*T / P in a range of from 0.05 to 10 kWh °C bar'1kg'1;(b) a T in a range of from 120 to 200 °C;(c) a P in a range of from 1 to 90 bar;(d) an SME of at least 0.05 kWh / kg, preferably in a range of from 0.05 to 0.50 kWh / kg;(e) a moisture content of the melt during extrusion in a range of from 10 to 50 wt%, as compared to the total weight of the melt; and / or(f) a torque in a range of from 15 to 75%; wherein SME (in kWh / kg) is the specific mechanical energy transferred from the extruder to the starting composition; P (in bar) is the pressure at the die of the extruder; and T (in °C) is the melt temperature at the die of the extruder.

5. The method according to any one of the preceding claims, wherein the extrusion process is characterized by:(a) a degradation factor defined as SME*T / P in a range of from 0.40 to 3.80 kWh °C bar'1kg'1; preferably of from 0.45 to 3.78 kWh °C bar'1kg'1;(b) a T in a range of from 170 to 200 °C; preferably of from 175 to 191 °C;(c) a P in a range of from 8 to 60 bar; preferably of from 10 to 56 bar;(d) a special mechanical energy (SME) in a range of from 0.140 to 0.230 kWh / kg; preferably of from 0.144 to 0.220 kWh / kg; and / or(e) a moisture content of the melt during extrusion in a range of from 18 to 25 wt%, preferably of from 20 to 22 wt%, as compared to the total weight of the melt; wherein SME (in kWh / kg) is the specific mechanical energy transferred from the extruder to the starting composition; P (in bar) is the pressure at the die of the extruder; and T (in °C) is the melt temperature at the die of the extruder.

6. The method according to any one of the preceding claims, wherein the extrusion process is characterized by(a) a degradation factor defined as SME*T / P in a range of from 0.45 to 3.78 kWh °C bar'1kg'1;(b) a T in a range of from 175 to 191 °C;(c) a P in a range of from 10 to 56 bar;(d) a special mechanical energy (SME) in a range of from 0.144 to 0.220 kWh / kg; and(e) a moisture content of the melt during extrusion in a range of from 20 to 22 wt%, as compared to the total weight of the melt; wherein SME (in kWh / kg) is the specific mechanical energy transferred from the extruder to the starting composition; P (in bar) is the pressure at the die of the extruder; and T (in °C) is the melt temperature at the die of the extruder.

7. The method according to any one of the preceding claims, wherein the native granular starch is a starch selected from the group consisting of waxy starch, amylose starch, and regular starch.

8. The method according to any one of the preceding claims, wherein the native granular starch is selected from the group consisting of com starch, potato starch, tapioca starch, faba starch, pea starch, wheat starch, arrowroot starch, sweet potato starch, yam starch, taro starch, and combinations thereof; wherein preferably the native granular starch is potato starch, corn starch, tapioca starch, or a combination thereof; and most preferably the native granular starch is potato starch.

9. The method according to any one of the preceding claims, wherein the native granular starch is potato starch.

10. The method according to any one of the preceding claims, wherein said starting composition has a moisture content in a range of from 18 to 30 wt%, preferably of from 19 to 28 wt.%, more preferably of from 20 to 25 wt%, relative to the total weight of the starting composition.

11. An extruded starch composition obtainable by the method according to any one of the preceding claims.

12. An extruded starch composition according to claim 11, wherein the extruded starch composition comprises at least a first starch mass fraction denoted as SMF1, a secondstarch mass fraction denoted as SMF2, and a third starch mass fraction denoted as SMF3, in which:(i) SMF1 has an Mw in a range of from 3850 to 13000 kDa; preferably of from 3900 to 12850 kDa;(ii) SMF2 has an Mw in a range of from 1100 to 4700 kDa; preferably of from 1137 to 4645 kDa;(iii) SMF3 has an Mw in a range of from 320 to 4500 kDa; preferably of from 355 to 4403 kDa;(iv) the extruded starch composition has an Mw in a range of from 1300 to 10000 kDa; preferably of from 1477 to 9216 kDa; and(v) the dispersity of the extruded starch composition has a value in a range of from 0.75 to 1.9; preferably of from 0.79 to 1.8; and wherein the Mw of SMF1 is different from the Mw of SMF2 and different from the Mw of SMF3; the Mw of SMF2 is different from the Mw of SMF3; and wherein Mw denotes the weight average molecular weight.

13. An extruded starch composition according to claim 11, wherein the extruded starch composition is a cold-water soluble thermoreversible gelling starch composition comprising at least two starch mass fractions Mwl and Mw2, in which a) starch mass fraction Mwl has a weight average molecular weight in a range of from 13 000 to 35 000 kDa; preferably of from 17 000 to 32 000 kDa; b) starch mass fraction Mw2 has a weight average molecular weight in a range of from 700 to 3000 kDa; preferably of from 750 to 2500 kDa; c) the sum of the starch mass fractions Mwl and Mw2 represents at least 50 wt.% of the total weight of the cold-water soluble thermoreversible gelling starch composition; and d) the mass ratio between the starch mass fractions Mwl and Mw2 is in a range of from 1.1 : 1 to 20 : 1.

14. A food item, a feed item, a thickening agent, an adhesive agent, a cosmetic product,paper, or a construction material, comprising an extruded starch composition according to any one of claims 11 to 13.

15. Use of an extruded starch composition according to any one of claims 11 to 13 as a food ingredient, a feed ingredient, a thickening agent, an adhesive agent, an ingredient for a cosmetic product, as an ingredient for the production of paper, and / or as a component of a construction material.

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