Unsubstituted pregelatinized starch and process for its preparation

Abstract

An unsubstituted crosslinked pregelatinized starch has a cold viscosity in the range of 500 cP to 3200 cP at neutral pH and 6 wt% solids, a retrogradation enthalpy of 2.3 J / g or less at 1 week and 7 J / g or less at 4 weeks, and a retrogradation end temperature of less than 75°C. The starch can be made from waxy cassava, waxy rice, waxy sugar-2 corn mutant, short chain waxy potato, waxy wheat, highly phosphorylated waxy starch, or a combination of any two or more thereof. The starch can be crosslinked. The starch can be used in food products, nutritional products, pharmaceutical products, personal care products, paper products, and the like. A method of making the starch includes mixing a native starch with water to form a slurry; adjusting the pH of the slurry to be alkaline; and mixing a crosslinking agent with the slurry to effect a crosslinking reaction.

Description

Cross-references to related applications

[0001] This application claims the benefit of U.S. Provisional Application No. 63 / 570,746, filed March 27, 2024, which is incorporated herein by reference in its entirety. Technical Field

[0002] This disclosure relates to modified starch. Specifically, this disclosure relates to unsubstituted cross-linked pregelatinized waxy starch, and to a method for preparing such modified starch. Background Technology

[0003] Starch typically contains two types of polymers: essentially linear amylose and branched amylopectin. Starches with low amylose content are often referred to as "waxy" starches. Exemplary sources of waxy starches include waxy cassava, waxy rice, waxy sugar-2 corn mutants, short-chain waxy potatoes, waxy wheat, and highly phosphorylated waxy starches. In nature, root and tuber starches typically have higher amounts (ranging from 80 ppm to 980 ppm) of covalently bound monophosphate esters. On the other hand, cereal starches such as corn, rice, and wheat typically have lower amounts of monophosphate esters (typically in the range of 0 ppm to 80 ppm). Starch phosphorylation catalyzed by proteins with glucan-water dual kinase (GWD) or phospho-glucan-water dual kinase (PWD) activity creates additional monophosphate ester bonds in the dextran chains. Covalently bound monophosphate esters can be enhanced through selective breeding programs or transgenic methods.

[0004] Starch is used to thicken (e.g., viscous) food and other products, such as cosmetics and pharmaceuticals. Starch is a semi-crystalline granule that is insoluble in cold water. However, if the granules are heated as a suspension in excess water, they swell extensively at temperatures up to a certain point and then disintegrate. Starches from different sources differ in texture, taste, and thickening properties. Virgin starch can be modified to better control the properties provided by the starch and improve its stability. Such properties include, for example, viscosity, texture (smoothness, non-stickiness), processing stability, cold storage stability, etc. Typically, substitution with various alkyl or hydroxyalkyl groups (such as acetyl or hydroxypropyl) has been used to provide cold storage stability and increased viscosity. Crosslinking has been used to control processing stability and maintain viscosity.

[0005] The aim is to improve the modified starch and its preparation method. Summary of the Invention

[0006] Modified starches are provided, specifically unsubstituted cross-linked pregelatinized waxy starches. In one aspect, the present invention provides an unsubstituted cross-linked pregelatinized starch having a cold viscosity (measured at neutral pH and 6% wt% solids) in the range of 500 cP to 3200 cP and a retrogradation enthalpy of 2.5 J / g or less measured after storage at 4°C for 1 week. The unsubstituted cross-linked pregelatinized starch may have a retrogradation enthalpy of 2.3 J / g or less measured after storage at 4°C for 1 week.

[0007] In one aspect, the present invention provides an unsubstituted cross-linked pregelatinized starch having a cold viscosity in the range of about 800 cP to about 3200 cP, measured at neutral pH and 6% wt% solids. The unsubstituted cross-linked pregelatinized starch may have a retrogradation enthalpy of 3 J / g or less at 1 week and 7 J / g or less at 4 weeks, and a retrogradation end temperature of less than 75°C. The unsubstituted cross-linked pregelatinized starch may have a cold viscosity in the range of about 800 cP to about 3200 cP, about 800 cP to about 3000 cP, about 1000 cP to about 3000 cP, about 1200 cP to about 2900 cP, about 1400 cP to about 2800 cP, about 1600 cP to about 2800 cP, or about 1800 cP to about 2600 cP. Unsubstituted cross-linked pregelatinized starch may have an enthalpy of retrogradation of about 2.8 J / g or less, about 2.5 J / g or less, about 2.4 J / g or less, about 2.3 J / g or less, about 2.2 J / g or less, about 2.1 J / g or less, or about 2.0 J / g or less, as measured after 1 week of refrigerated storage. Unsubstituted cross-linked pregelatinized starch may have an enthalpy of retrogradation of about 0.7 J / g or greater, about 0.8 J / g or greater, about 0.9 J / g or greater, or about 1.0 J / g or greater, as measured after 1 week of refrigerated storage. When stored under refrigeration for 4 weeks, unsubstituted cross-linked pregelatinized starch may have a retrogradation enthalpy of about 7 J / g or less, about 6.7 J / g or less, about 6.5 J / g or less, about 6.3 J / g or less, about 6.2 J / g or less, about 6.1 J / g or less, or about 6.0 J / g or less.

[0008] Unsubstituted cross-linked pregelatinized starch can be prepared from any waxy starch source, including waxy cassava, waxy rice, waxy sugar-2 corn mutant, short-chain waxy potato, waxy wheat, hyperphosphorylated waxy starch, or any combination of two or more thereof. The unsubstituted cross-linked pregelatinized starch may be cross-linked. In some aspects, the unsubstituted cross-linked pregelatinized starch may include or may have unsubstituted cross-linked waxy cassava starch. The unsubstituted cross-linked pregelatinized starch can be cross-linked using any suitable cross-linking agent, such as sodium trimetaphosphate, phosphorus oxychloride, adipic acid, adipate, epichlorohydrin, or any combination of two or more thereof. In some aspects, the unsubstituted cross-linked pregelatinized starch is prepared from waxy sugar-2 corn mutant and has an enthalpy of retrogradation of 1.5 J / g or less when stored at 4°C for 1 week.

[0009] Unsubstituted cross-linked pregelatinized starch may contain about 5% by weight or less amylose. In some respects, unsubstituted cross-linked pregelatinized starch may contain no or substantially no amylose.

[0010] Unsubstituted cross-linked pregelatinized starch can be prepared from cassava plants, including but not limited to cassava plants modified using CRISPER / Cas9 technology. Additionally or alternatively, in any aspect of this document, unsubstituted cross-linked pregelatinized starch can be prepared from naturally occurring waxy cassava plants or waxy cassava plants developed through non-genetic modification or conventional breeding.

[0011] According to some aspects of the present invention, the unsubstituted cross-linked pregelatinized starch is not hydroxypropylated or acetylated.

[0012] According to some aspects of the present invention, the unsubstituted cross-linked pregelatinized starch is intact. According to some aspects of the present invention, the unsubstituted cross-linked pregelatinized starch is agglomerated.

[0013] Unsubstituted cross-linked pregelatinized starch can be stable in 2 or more, 3 or more, 4 or more, 5 or more, 6 or more, 8 or more, or 10 or more freeze-thaw cycles. According to some aspects of the invention, unsubstituted cross-linked pregelatinized starch is stable in 4 or more freeze-thaw cycles.

[0014] In another aspect, the present invention provides food products comprising unsubstituted cross-linked pregelatinized starch. The food product may be a dairy product. The dairy product may be or may include dairy-based desserts, instant puddings, instant cheeses, cream sauces, or any combination of two or more of these. The food product may be non-dairy yogurt or non-dairy pudding. The food product may be an instant sauce, soup, gravy, salad dressing (spoonable or pourable), cold mayonnaise, dip, spread, icing mixture, custard, whipped topping, baking filling (instant fruit or cream filling), ready-to-eat meals (cold prepared and frozen), instant toppings (pizza, fruit), or dry mixes. The food product may be pet food, retort pouch food, or canned pet food.

[0015] The food product may contain unsubstituted cross-linked pregelatinized starch in proportions of about 1% or more, about 2% or more, about 5% or more, about 7.5% or more, about 10% or more, about 12.5% ​​or more, about 15% or more, or about 20% or more, based on the total weight of the food product. Unsubstituted cross-linked pregelatinized starch may be contained in proportions of about 35% or less, about 30% or less, about 25% or less, about 20% or less, about 15% or less, or about 10% or less, based on the total weight of the food product. In some aspects, unsubstituted cross-linked pregelatinized starch comprises about 1% to about 35% by weight, or about 5% to about 25% by weight of the food product.

[0016] In another aspect, the present invention provides a method for preparing unsubstituted crosslinked pregelatinized starch as described in any aspect herein. The method may include mixing native starch with water to form a slurry; adjusting the pH of the slurry to an alkaline pH; and mixing a crosslinking agent with the slurry to achieve a crosslinking reaction. The starch may be pregelatinized during or after crosslinking. In some cases, crosslinking may be performed in two steps, one step prior to pregelatinization and the second step after pregelatinization. The resulting unsubstituted crosslinked pregelatinized starch exhibits a cold viscosity (measured at neutral pH and 6% wt% solids) in the range of about 500 cP to about 3200 cP and an enthalpy of retrogradation of 2.5 J / g or less measured after storage at 4°C for 1 week. The resulting unsubstituted crosslinked pregelatinized starch may exhibit an enthalpy of retrogradation of about 2.3 J / g or less at 1 week and about 7 J / g or less at 4 weeks and a retrogradation end temperature of less than about 75°C.

[0017] The slurry may contain approximately 20% to approximately 45% virgin starch dry solids. The pH of the slurry may be adjusted to a range of approximately 9 to approximately 13. The crosslinking reaction may be carried out at a reaction temperature of approximately 24°C to approximately 45°C and for a duration of approximately 0.5 h to approximately 10 h.

[0018] The crosslinking agent added to the slurry may include sodium trimetaphosphate, phosphorus oxychloride, adipic acid, adipic acid, epichlorohydrin, citric acid, or any combination of two or more thereof. The method may also include mixing a salt into the slurry. The slurry may contain 0.5% to 10% by weight of salt.

[0019] The method may also include adjusting the pH to a range of 4.5 to 6.5 after crosslinking.

[0020] The method may also include dehydrating and drying the starch.

[0021] Native starch may include waxy cassava, waxy rice, waxy sugar-2 corn mutant, short-chain waxy potato, waxy wheat, highly phosphorylated waxy starch, or any combination of two or more of these. Native starch may contain 5% by weight or less amylose. In some respects, native starch contains no or substantially no amylose.

[0022] According to some aspects of the present invention, native starch may include waxy cassava starch, and unsubstituted cross-linked pregelatinized starch includes unsubstituted cross-linked waxy cassava starch.

[0023] Unsubstituted cross-linked pregelatinized starch can exhibit cold viscosity in the range of 1200 cP to 3000 cP.

[0024] This method may be free of hydroxypropylation or acetylation.

[0025] definition

[0026] Unless otherwise specified, all scientific and technical terms used herein have their common meaning in the art. The definitions provided herein are for the purpose of facilitating understanding of certain terms frequently used herein and are not intended to limit the scope of this disclosure.

[0027] The term "cassava starch" is used here to refer to starch obtained from the roots of the cassava plant (Manihot esculenta).

[0028] The term “waxy starch” is used here to refer to starch with a low amylose content, such as starch containing 5% or less by weight, 3% or less by weight, 2% or less by weight, or no amylose.

[0029] The term "gelatinization" is used here to refer to the phase change of starch when heated in excess water, during which semi-crystalline starch granules undergo a state change from an ordered structure to a disordered structure.

[0030] The term "retrogradation" refers to the reassociation of disordered dextran chains in gelatinized starch into an ordered structure via hydrogen bonding. During this rearrangement, the reduced intermolecular distances between the dextran chains lead to water removal from the gel, a phenomenon known as "dehydration shrinkage." Starch retrogradation, including retrogradation enthalpy and melt transition temperature, can be characterized using differential scanning calorimetry (DSC). Retrogradation enthalpy reflects the melting of microcrystals in retrograded starch or the unwinding of the amylopectin double helix. Melt transition temperatures are described as the onset temperature (To) and the end temperature (Tc). The melting temperature range reflects the temperature between the onset of microcrystal melting and the end temperature. The end temperature Tc may be referred to as the retrogradation end temperature or the temperature at which retrogradation ends. Measurements of retrogradation enthalpies To and Tc are also discussed in Vamadevan and Bertoft, Impact of Different Structural Types of Amylopectin on Retrogradation, Food Hydrocolloids 80 (2018) 88.

[0031] The terms “stable” and “stability” are generally used to refer to the ability to maintain structure, texture, and / or viscosity. In the context of starch, the terms “stable” and “stability” can be used to refer to various aspects of stability, including processing stability and refrigeration stability under elevated heat and shear (shear conditions). Chemically cross-linked starches provide the desired smooth texture and exhibit viscosity stability throughout the processing operation. A lack of processing stability can be inferred from the loss of viscosity and the development of undesirable texture during processing (e.g., under acidic or high-shear conditions). Processing stability can include tolerance to processing conditions such as heat, acid, shear stress, etc. Refrigeration stability can include both stability at refrigerated temperatures and freeze-thaw stability (stability during freeze-thaw cycles). Refrigeration stability at refrigerated temperatures can be determined by measuring the retrogradation enthalpy of starch after storage at refrigerated temperatures (e.g., 1 week or 4 weeks). A lower retrogradation enthalpy indicates improved refrigeration stability at refrigerated temperatures. Freeze-thaw stability can be determined by exposing starch to multiple freeze-thaw cycles and observing changes in the starch (e.g., water separation). A higher number of cycles without change indicates improved freeze-thaw stability.

[0032] The term "refrigeration temperature" is used here to refer to the temperature range of approximately 2°C to approximately 6°C, which is typically used in refrigeration units. When used in the context of stability testing, the term "refrigeration temperature" is used to mean approximately 4°C.

[0033] The term "viscous starch" is used to refer to starches that impart increased viscosity.

[0034] The term "hyperphosphorylated" is used herein to refer to plant varieties containing at least 10%, at least 20%, or at least 30% more monophosphate esters than conventional varieties. Conventional plant varieties include those containing monophosphate esters naturally produced during starch metabolism in the plant, without selective breeding or overexpression of GWD through transgenic methods.

[0035] Unless otherwise specified, the terms "polymer" and "polymer material" include, but are not limited to, organic homopolymers, copolymers (such as, for example, block, graft, random and syndiotactic copolymers, terpolymers, etc.), and blends and modifications thereof. Furthermore, unless otherwise specifically limited, the term "polymer" shall include all possible geometries of the material. These geometries include, but are not limited to, isotactic, syndiotactic, and atactic symmetries.

[0036] The term "alkylated" is used in this disclosure to describe compounds that undergo a reaction to replace hydrogen atoms or negative charges of the compound with alkyl groups, such that the alkyl groups are covalently bonded to the compound.

[0037] The term "alkyl" is used in this disclosure to describe a monovalent group that is an alkane group and includes straight-chain, branched, cyclic, and bicyclic alkyl groups and combinations thereof, including both unsubstituted and substituted alkyl groups. Unless otherwise specified, alkyl groups generally contain 1 to 30 carbon atoms. In any aspect thereof, alkyl groups contain 1 to 20 carbon atoms, 1 to 10 carbon atoms, 1 to 6 carbon atoms, 1 to 4 carbon atoms, or 1 to 3 carbon atoms. Generally, alkyl groups are attached to the remainder of the molecule by a single bond, and for example, alkyl groups may include, but are not limited to, methyl, ethyl, n-propyl, n-butyl, n-pentyl, isobutyl, tert-butyl, isopropyl, n-octyl, n-heptyl, ethylhexyl, cyclopentyl, cyclohexyl, cycloheptyl, etc. In some aspects, alkyl groups are optionally substituted by one or more of the following substituents: halogroup, cyanogroup, nitrogroup, oxogroup, thiogroup, -OR group. a -SR a -OC(O)-R b -N(R) a )2、-C(O)OR a -C(O)N(R) a )2-、-N(R a )C(O)OR a -N(R) a )C(O)R a 、N(R a )S(O)2 R b -S(O)2O R a and -S(O)2N(R a )2, where each R aIndependently, it is hydrogen, alkyl, fluoroalkyl, cycloalkyl, aryl, heterocyclic, or heteroaryl, and each R b It is independently hydrogen, alkyl, fluoroalkyl, cycloalkyl, aryl, heterocyclic or heteroaryl.

[0038] As used herein, the term “substantially” has the same meaning as “significantly” and is to be understood as modifying the following term by at least about 95%, at least about 98%, at least about 99%, or at least about 99.5%. The term “substantially free of” a particular compound means that the compositions of this disclosure contain less than 0.1% of the stated compound.

[0039] As used herein, the term “substantially not” has the same meaning as “not significantly” and can be understood as having the opposite meaning of “substantially”, i.e., modifying the following term by no more than 10%, no more than 5%, or no more than 2%.

[0040] Furthermore, it should be understood that the wording or terminology used herein, unless otherwise defined, is for descriptive purposes only and not for limitation. Any use of section headings is intended to aid reading the document and should not be construed as restrictive; information relating to a section heading may appear within or outside that particular section. Any publications, patents, and patent documents cited in this document are incorporated herein by reference in their entirety as if they were individually cited. In the event of any inconsistency between the usage in this document and those documents so cited, the usage in the incorporated references shall be considered supplementary to the usage in this document; in the case of irreconcilable inconsistencies, the usage in this document shall prevail.

[0041] As used herein, the terms “for example,” “to illustrate,” or “such as” are intended to provide examples that further illustrate a more general subject. Unless otherwise stated, these examples are provided merely to aid in understanding the application of the descriptions in this disclosure and are not intended to be limiting in any way.

[0042] In the methods described herein, actions may be performed in the specific order listed herein. Alternatively, in any aspect disclosed herein, specific actions may be performed in any order without departing from the premises of this disclosure, unless the timing or order of operations is expressly specified. Furthermore, specified actions may be performed simultaneously unless the explicit language of the claims states that they are performed separately or the express meaning of the claims requires so. For example, the claimed action of performing X and the claimed action of performing Y may be performed simultaneously in a single operation, and the resulting process will fall within the literal scope of the claimed process.

[0043] The term “about” is used herein in conjunction with numerical values ​​to include normal variation in measured values ​​as would be expected by those skilled in the art, and is understood to have the same meaning as “approximately”, and covers typical error ranges such as ±10%, ±5% or ±1% of the stated value or the limits of the stated range, and includes precise stated values ​​or ranges.

[0044] Terms such as “a / kind” and “the / described” and similar referents are not intended to refer only to singular entities, but to include general categories whose specific examples may be used to illustrate them. It should be understood that, unless otherwise indicated herein or clearly contradicted by the context, any term used in the singular form may include its plural counterpart, and vice versa.

[0045] The terms “one / kind” and “the / described” are used interchangeably with the term “at least one / kind”. The phrases “at least one / kind of…” and “containing at least one / kind of…” that follow the list refer to any one item in the list and any combination of two or more items in the list.

[0046] As used herein, the term "or" is used in its common sense, including "and / or," unless otherwise expressly stated. The term "and / or" means one or all of the listed elements or a combination of any two or more of the listed elements.

[0047] A range of values ​​expressed by endpoints includes all values ​​included within that range (e.g., 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4, 5, etc., or 10 or less includes 10, 9.4, 7.6, 5, 4.3, 2.9, 1.62, 0.3, etc.). Where the range of values ​​is "at most" or "at least" a specific value, that value is included within the range, and refers to a range that can subsequently be decomposed into subranges as discussed above. Finally, as those skilled in the art will understand, a range includes each individual member.

[0048] As used herein, “comprising,” “including,” etc., are used in their open-ended sense and generally mean “including but not limited to.” It should be understood that “consistently composed of,” “comprises of,” etc., are included in “comprising.” Furthermore, the terms and expressions used herein are used as descriptive rather than limiting terms and are not intended to exclude any equivalents of the features shown and described or portions thereof; however, it should be recognized that various modifications are possible within the scope of the claimed technology. As used herein, “consistently composed of” when referring to compositions, products, methods, etc., means that the components of the composition, product, method, etc., are limited to the listed components and any other components that do not materially affect the essential and novel characteristics of the composition, product, method, etc. The phrase “comprises of” does not include any unspecified elements.

[0049] The terms "preferred" and "ideally" refer to aspects of the invention that provide certain benefits in certain circumstances. However, other aspects may also be preferred in the same or other circumstances. Furthermore, the statement of one or more preferred aspects does not imply that other aspects are not available, and is not intended to exclude other aspects from the scope of this disclosure, including the claims. Detailed Implementation

[0050] Reference will now be made to certain aspects of the disclosed subject matter in detail. While the disclosed subject matter will be described in conjunction with the enumerated claims, it should be understood that the illustrated subject matter is not intended to limit the claims to the disclosed subject matter. An aspect described in conjunction with a particular aspect is not necessarily limited to that aspect and may be practiced in conjunction with any other aspect.

[0051] This disclosure relates to modified starches. Specifically, this disclosure relates to unsubstituted cross-linked waxy starches, and more specifically to unsubstituted cross-linked pregelatinized starches. The starches of this disclosure are cold-stabilized, thickening starches exhibiting good freeze-thaw stability. These next-generation cold-stabilized starches can be prepared without substitution (e.g., without hydroxypropyl or acetyl substitution), providing improved operational safety, reduced production costs, and environmental benefits, including less wastewater, less salt use, and reduced reaction time and energy use, thereby reducing the carbon footprint and increasing the sustainability of the modified starches. The lack of substitution also helps avoid any supply problems with certain industrial chemicals, such as propylene oxide, which is commonly used in hydroxypropylation reactions. The cold-stabilization of the unsubstituted cross-linked pregelatinized starches of this disclosure is comparable to that of hydroxypropyl-substituted cross-linked pregelatinized starches. The unsubstituted cross-linked pregelatinized starches of this disclosure can be used as substitutes or alternatives to low- or moderately hydroxypropyl-substituted or highly hydroxypropyl-substituted starches.

[0052] The unsubstituted cross-linked pregelatinized starch disclosed herein can be used as a substitute or alternative to acetylated or hydroxypropylated pregelatinized starch.

[0053] Unreplaced cross-linked starch

[0054] In one aspect, the present invention provides an unsubstituted cross-linked pregelatinized starch having a cold viscosity in the range of about 500 cP to about 3200 cP, measured at neutral pH and about 5.5% by weight solids, wherein the unsubstituted cross-linked pregelatinized starch has a retrogradation enthalpy of about 3 J / g or less at 1 week and about 7 J / g or less at 4 weeks and a retrogradation end temperature of less than about 75°C.

[0055] In either case, unsubstituted cross-linked pregelatinized starch can be prepared from waxy cassava starch. Regular cassava starch contains approximately 18% to approximately 23% by weight of amylose, with the remainder being amylopectin. Cassava starch with low amylose content contains higher levels of amylopectin and lower levels of amylose than regular cassava starch. Waxy cassava starch also contains higher levels of amylopectin and lower levels of amylose than regular cassava starch, and can be used herein to refer to cassava starch with very low amylose content. Waxy cassava starch may contain approximately 5% or less, approximately 3% or less, or approximately 1.5% or less of amylose, or may be synthesized from a mutant lacking the functional GBSS I gene and containing no amylose. The term “GBSS I” should be understood to mean any enzyme belonging to subtype I of granule-bound starch synthase (EC 2.4.1.21).

[0056] According to one aspect of the present invention, the substituted cross-linked pregelatinized starch may have a chain length distribution according to Table 1 below.

[0057]

[0058] In Table 1, "Dp" refers to the degree of polymerization, and "Afp" refers to the fingerprint A-chain of amylopectin. Afp chains, also known as dangling chains, are too short to participate in the formation of the double helix during retrogradation. The fingerprint A-chain (Afp) is a unique subtype of amylopectin with the shortest chain at Dp 6-8, and its characteristics are specific to plant-derived starches. Amylopectin molecules with a higher proportion of shorter chains are less susceptible to the effects of retrogradation.

[0059] Dp can be measured by high-performance anion exchange chromatography (HPAEC) as follows: A starch sample (2 mg) was dissolved in 90% dimethyl sulfoxide (DMSO; 50 μL) and heated in a hot water bath (80 °C) for 5 min, followed by stirring for 1 h. Warm (80 °C) water (400 μL) was then added to the sample, followed by 50 μL of 0.01 M sodium acetate buffer (pH 5.5) and allowed to cool to room temperature. Isoamylase (1 μL, 465 U / mL) and pullulanase M1 (925 U / mL) (Megazyme) were added, and the mixture was slowly stirred overnight at room temperature (25 °C) to debranch the starch. After debranching, the enzyme was inactivated by boiling for 5 min, the volume was adjusted to obtain a final concentration of 1 mg / mL, and the sample was filtered through a 0.45 µm nylon filter. The filtered sample was injected into an HPAEC system equipped with a Carbopac PA-100 ion exchange column with a pulsed amperometric detector. The sample was then eluted at a flow rate of 1 mL / min. The sample was eluted with eluent B in the following gradient: 0–9 min, 15–36% B; 9–18 min, 36–45% B; 18–110 min, 45–100% B. The column was equilibrated with 15% B for 60 min between runs. Eluent A was 0.15 M NaOH (7.85 mL / 1000 mL), and eluent B was 0.15 M NaOH containing 0.50 M NaAc (for 1 L, 7.85 mL NaOH / 41 g NaOAc).

[0060] According to one aspect of the invention, the unsubstituted cross-linked pregelatinized starch has 18% by weight or more of chains with a Dp of 13 or less. The unsubstituted cross-linked pregelatinized starch may have 48% by weight or less of chains with a Dp of 13-24. The unsubstituted cross-linked pregelatinized starch may have 16% by weight or more of chains with a Dp of 6-12. The unsubstituted cross-linked pregelatinized starch may have 1.5% by weight or more of chains with a Dp of 6-8.

[0061] Waxy cassava starch can be obtained from waxy cassava plants. Recessive waxy cassava mutants have been found in nature. Waxy cassava can be obtained through classical breeding and hybridization breeding techniques, or through translocation, inversion, transformation, or any other gene or chromosome engineering method (including CRISPR / Cas9 technology). The term CRISPR as used in this art refers to clustered, regularly spaced short palindromic repeat sequences. CRISPR / Cas9 refers to CRISPR-associated protein 9. CRISPR / Cas9-mediated targeted mutagenesis of two genes involved in amylose biosynthesis (targeting amylose protein (PTST1) or granule-bound amylose synthase (GBSS)) can reduce or eliminate amylose content in root starch. Waxy cassava starch can be extracted from the roots of cassava plants with low amylose content. Extraction can be carried out by any known method, such as crushing the roots and extracting starch from the crushed roots with water. The extracted starch can be considered unmodified native starch.

[0062] Substitution of starch is understood to mean chemical derivatization using any suitable modification technique to form ethers, esters, or hemiesters, such as hydroxyalkyl ethers, acetates, phosphates, succinates (e.g., octenyl succinate), tertiary amine ethers, or quaternary amine ethers. Typically, starch is substituted by reacting it with alkylene oxides to form hydroxyalkyl ether derivatives. Etherification of starch improves its functional properties in many ways. Hydroxypropylation and crosslinking are often used together to produce crosslinked stabilized starches, which are widely used in thickening and stabilizing food applications.

[0063] According to this disclosure, in any aspect, the starch is unsubstituted. It should be noted that crosslinking is not considered substitution. In any aspect, the starch as described herein may be free of any other modifications (other than crosslinking). The starch of this disclosure may be characterized as unsubstituted crosslinked pregelatinized starch. For example, the starch may be free of substitution, enzymatic modification, pregelatinization, or any combination of two or more of these. In any aspect, the starch is free of both substitution and enzymatic modification. In any aspect, the starch is free of both substitution and enzymatic modification, but has been pregelatinized. The unsubstituted crosslinked pregelatinized starch of this disclosure has been found to be functionally similar to hydroxypropylated crosslinked waxy corn starch in terms of viscosity and cold storage stability. Unsubstituted crosslinked pregelatinized starch helps eliminate the typical sodium sulfate waste stream associated with industrial propylene oxide-starch reactions and provides energy savings and increased manufacturing capacity by reducing reaction time from about 22 h to less than about 8 h.

[0064] In any aspect, the starch disclosed herein is cross-linked. The starch can be cross-linked using a cross-linking agent. Suitable cross-linking agents include epichlorohydrin, linear dicarboxylic anhydride, citric acid, sodium trimetaphosphate, phosphorus oxychloride, adipic acid, adipic acid salt, trimetaphosphate, mixtures of sodium trimetaphosphate and sodium tripolyphosphate, linear dicarboxylic anhydride, citric acid, adipic acid salt, formaldehyde, cyanuric chloride, diisocyanate, divinyl sulfone, and any combination of two or more thereof. In any aspect, the cross-linking agent includes sodium trimetaphosphate (STMP), phosphorus oxychloride (POCl3), adipic acid salt, epichlorohydrin, or any combination of two or more thereof. In any aspect, the unsubstituted cross-linked pregelatinized starch is suitable for use in food products. Such starch can be cross-linked using a cross-linking agent suitable for food applications. For example, starch intended for use in food products can be cross-linked using sodium trimetaphosphate, or phosphorus oxychloride, or a mixture of sodium trimetaphosphate and sodium tripolyphosphate.

[0065] Unsubstituted cross-linked pregelatinized starch can be provided in any desired form. When dispersed in cold or warm water, pregelatinized starch can produce viscosity without further heating. Pregelatinized starch is also known as precooked starch, instant starch, cold-water soluble starch, or cold-water swellable starch. According to some aspects of the invention, unsubstituted cross-linked pregelatinized starch can be a cold-water swellable or instant product. Unsubstituted cross-linked pregelatinized starch can agglomerate.

[0066] Depending on several factors, unsubstituted cross-linked pregelatinized starch can be intact. Depending on processing conditions, sometimes starch granules cannot completely disintegrate. "Intact" means that the starch granules in pregelatinized starch are at least partially intact.

[0067] Methods for preparing unsubstituted cross-linked starch

[0068] In either case, the method for preparing the unsubstituted cross-linked pregelatinized starch described herein includes cross-linking and pregelatinization. This method may also include other process steps discussed herein.

[0069] The cross-linking reaction can be carried out using techniques known in the art, such as those described in U.S. Patent Nos. 2,328,537 and 2,801,242, the entire contents of which are incorporated herein by reference. To prepare unsubstituted cross-linked pregelatinized starch, virgin starch can be mixed with an aqueous solvent or water to form a slurry. The virgin starch may be present in a solids content of about 5% by weight or more, about 10% by weight or more, about 15% by weight or more, about 20% by weight or more, about 25% by weight or more, about 30% by weight or more, or about 35% by weight or more, based on the weight of the slurry. The virgin starch may be present in a solids content of about 45% by weight or less, about 40% by weight or less, or about 35% by weight or less, based on the weight of the slurry. The virgin starch may be present in a solids content of about 20% by weight to about 45% by weight, about 30% by weight to about 45% by weight, or about 30% by weight to about 40% by weight, based on the weight of the slurry. The pH of the slurry can be adjusted to alkaline. For example, the pH of the slurry can be adjusted to a range of about 9 to about 13, or about 10 to 13, or about 11 to about 12. The pH of the slurry can be adjusted with any suitable base that does not interfere with the reaction. For example, the pH of the slurry can be adjusted using sodium hydroxide (NaOH), potassium hydroxide (KOH), sodium carbonate (Na2CO3), potassium carbonate (K2CO3), or any combination of two or more of these. The slurry may also contain salts such as sodium chloride (NaCl), sodium sulfate (Na2SO4), calcium chloride (CaCl2), or any combination of two or more of these. Salts can be used to control the swelling of starch during the cross-linking reaction. The inclusion of salts can also enhance the cross-linking reaction. Salts can be contained in the slurry at concentrations of 0.5% by weight or more, about 1% by weight or more, about 2% by weight or more, about 3% by weight or more, or about 4% by weight or more. Salts can be contained in the slurry at concentrations of about 10% by weight or less, about 8% by weight or less, about 7% by weight or less, or about 6% by weight or less.

[0070] Crosslinking agents can be mixed into the slurry at appropriate concentrations, depending on the crosslinking agent and the desired degree of crosslinking. The degree of crosslinking can be adjusted based on the desired viscosity. In either case, the amount of crosslinking agent is limited by regulatory restrictions on certain compounds (such as phosphates) in food products. Based on dry weight, the amount of crosslinking agent in the slurry can range from about 0.001 wt% to about 1.0 wt%, or from 0.008 wt% to 0.1 wt%. In either case, based on dry weight, the amount of crosslinking agent in the slurry is 0.5 wt% or less, 0.4 wt% or less, 0.25 wt% or less, or 0.1 wt% or less. The amount of crosslinking agent in the slurry can range from 0.01 wt% to 0.1 wt%. In either case, the amount of crosslinking agent is limited based on the amount present in the final product. For example, the amount of residual phosphates in food products and food ingredients may be limited. The amount of crosslinking agent in the final product (e.g., crosslinked pregelatinized starch) may be 0.4% by weight or less, 0.1% by weight or less, or 0.04% by weight or less, calculated based on phosphorus. Crosslinking reaction conditions may include elevated temperatures, such as about 25°C or higher, about 28°C or higher, or about 32°C or higher. Crosslinking temperatures may be about 60°C or lower, or about 50°C or lower. The duration of the crosslinking reaction may depend on the crosslinking agent and the desired degree of crosslinking. In some cases, the duration of the crosslinking reaction may be as short as about 5-15 minutes (e.g., about 10 minutes). In some aspects, the duration may be longer than about 15 minutes, such as about 30 minutes or longer, about 60 minutes or longer, about 2 hours or longer, about 3 hours or longer, about 4 hours or longer, or about 5 hours or longer. The duration may be about 24 hours or less, about 18 hours or less, about 12 hours or less, about 10 hours or less, or about 8 hours or less. The slurry can be held at the reaction temperature for an additional period of time (holding time). Holding time can be approximately 10 minutes or longer, approximately 20 minutes or longer, approximately 30 minutes or longer, or approximately 45 minutes or longer. Holding time can be up to approximately 24 hours, up to approximately 12 hours, up to approximately 6 hours, up to approximately 3 hours, up to approximately 2 hours, or up to approximately 1.5 hours. Holding time can be, for example, approximately 1 hour.

[0071] Following the crosslinking reaction, the pH of the slurry can be adjusted back down. For example, the pH of the slurry can be adjusted to a range of approximately 4 to approximately 7.5, approximately 4.5 to approximately 6.5, or approximately 5 to approximately 6. In any case, the pH of the slurry can be adjusted to approximately 5.5. The pH of the slurry can be adjusted using any suitable acid, such as hydrochloric acid (HCl), phosphoric acid (H3PO4), citric acid, acetic acid, sulfuric acid, or any combination of two or more of these.

[0072] According to any aspect of this disclosure, the chemical modification of starch involves only cross-linking. The chemical modification of starch may not involve substitution reactions such as hydroxypropylation and acetylation.

[0073] Unsubstituted cross-linked pregelatinized starch can be processed to be supplied in any desired form. Pregelatinized starch can be prepared by drum drying, spray cooking and drying, or extrusion. When dispersed in cold or warm water, pregelatinized starch can produce viscosity without further heating. Pregelatinized starch is also known as precooked starch, instant starch, cold water soluble starch, or cold water swellable starch. In any case, unsubstituted cross-linked starch is a cold water swellable or instant product. Pregelatinized starch can be prepared by spray cooking and drying, roller (drum) drying, or any other thermal technique known to a person skilled in the art. Unsubstituted cross-linked pregelatinized starch can agglomerate.

[0074] According to any aspect of this disclosure, the method includes gelatinizing starch to produce pregelatinized cross-linked starch. The starch may be pregelatinized during or after cross-linking. Pregelatinized or cooked starch refers to swollen starch granules that have lost their birefringence and Maltese cross. Pregelatinized swollen starch may be whole or fragmented.

[0075] Pregelatinization is a physical method in which a slurry of granular natural (or cross-linked) starch is converted into swollen starch granules in the presence of water, heat, and pressure. The starch of the present invention can be gelatinized by any known method. For example, U.S. Patent No. 3,630,775 (granted to Winkler on December 28, 1971) describes a spray drying method in which the starch slurry is kept under pressure during heating and continues to be kept under pressure during the atomization step. Unmodified, ungelatinized starch is slurried in water with a solids content between about 10% by weight and 40% by weight, raised to a high temperature under pressure exceeding about 325°F, and spray-dried under pressure until the moisture content is less than 15%. Pressure is interdependent with viscosity, temperature, and equipment. Pressure is the pressure level used for atomization and exceeds the pressure that will prevent the water in the high-solids slurry from evaporating at the elevated temperature. Heating time is sufficient to allow the starch (if previously ungelatinized) to be substantially completely gelatinized and dissolved. Typically, the slurry (10% to 40% solids) is preheated to 54°C to 171°C, pumped through a continuous tubular heat exchanger at 2,000 psi to 6,800 psi, and heated to 182°C to 304°C (resulting in a starch temperature of 163°C to 232°C). The starch is retained in the cooker for 1.0 to 2.5 minutes. A conventional spray dryer with pressure-type atomizing nozzles can be used. The resulting starch is more than 50% soluble in cold water.

[0076] Pregelatinized starch can also be prepared by a conventional two-step spray cooking and spray drying method. Improvements to the conventional method are described in U.S. Patent No. 2,314,459 (granted March 23, 1943, to Salzburg) and U.S. Patent No. 3,332,785 (granted July 25, 1967, to Kurchinke et al.).

[0077] The pregelatinized starch of this invention can be roller-dried starch. Roller-dried starch is pregelatinized (instantly dissolved) by drying it on a steam-heated roller.

[0078] The pregelatinized starch of this invention can be cold-water swollen starch. The cold-water swollen starch is pregelatinized (instantly dissolved) by atomizing and steam-cooking the starch slurry in a spray nozzle, followed by drying in a spray tower.

[0079] Characteristics of unsubstituted cross-linked starch

[0080] According to any aspect of the invention, unsubstituted cross-linked pregelatinized starch can exhibit a variety of desired properties. The properties described herein are applicable to any unsubstituted cross-linked pregelatinized starch, including unsubstituted cross-linked pregelatinized starch. The properties of starch can be characterized by various measurements. For example, the properties of starch can be characterized by measuring its cold viscosity, retrogradation enthalpy, retrogradation end temperature, or any combination of two or more of these. Cold viscosity is typically measured at neutral pH or at neutral or near-neutral pH (e.g., at pH about 6). Cold viscosity can be measured using a rapid viscosity analyzer (RVA). An RVA is a heated and cooled viscometer that measures the viscosity of a sample over a given time period while the sample is stirred. As used herein, the cold viscosity of a sample refers to the viscosity after 30 minutes at 30°C. It corresponds to the viscosity after a total run time of 34 minutes and 10 seconds.

[0081]

[0082] Retrogenerating enthalpy can be measured using differential scanning calorimetry (DSC). Retrogenerating enthalpy can be measured at different time intervals, such as after one week of storage and after four weeks of refrigerated storage.

[0083] According to any aspect of this disclosure, the unsubstituted cross-linked pregelatinized starch has a cold viscosity (measured at neutral pH and 6% wt) of about 500 cP or greater, about 1000 cP or greater, about 1200 cP or greater, about 1400 cP or greater, about 1500 cP or greater, about 1600 cP or greater, about 1700 cP or greater, or about 1800 cP or greater. The unsubstituted cross-linked pregelatinized starch may have a cold viscosity (measured at neutral pH and 6% wt) of about 3200 cP or less, about 3100 cP or less, about 3000 cP or less, about 2900 cP or less, or about 2800 cP or less. The cold viscosity of unsubstituted cross-linked pregelatinized starch can be in the range of about 500 cP to about 3200 cP, about 500 cP to about 3000 cP, about 1000 cP to about 3000 cP, about 1200 cP to about 2900 cP, about 1400 cP to about 2800 cP, about 1600 cP to about 2800 cP, or about 1800 cP to about 2600 cP.

[0084] According to any aspect of this disclosure, the unsubstituted cross-linked pregelatinized starch has a low retrogradation enthalpy and a low retrogradation end temperature. Starches with low retrogradation end temperature and low retrogradation enthalpy are less prone to retrogradation. Starches with low retrogradation end temperature and low retrogradation enthalpy exhibit good refrigeration stability. The retrogradation enthalpy of the unsubstituted cross-linked pregelatinized starch of this disclosure may be low (e.g., lower than previously known starches) after refrigerated storage for 1 week and 4 weeks. According to any aspect of this disclosure, the unsubstituted cross-linked pregelatinized starch has a retrogradation enthalpy of about 3 J / g or less, about 2.8 J / g or less, about 2.5 J / g or less, about 2.4 J / g or less, about 2.3 J / g or less, about 2.2 J / g or less, about 2.1 J / g or less, or about 2.0 J / g or less, measured after 1 week of refrigerated storage. Unsubstituted cross-linked pregelatinized starch may have an enthalpy of retrogradation of 0.7 J / g or greater, 0.8 J / g or greater, 0.9 J / g or greater, or about 1.0 J / g or greater, as measured after 1 week of refrigerated storage. Unsubstituted cross-linked pregelatinized starch may have an enthalpy of retrogradation of 0.7 J / g to about 3 J / g, 0.8 J / g to about 2.5 J / g, 0.8 J / g to about 2.4 J / g, or about 1.0 J / g to about 2.3 J / g, as measured after 1 week of refrigerated storage. After 4 weeks of refrigerated storage, unsubstituted cross-linked pregelatinized starch may have an enthalpy of retrogradation of about 7 J / g or less, about 6.7 J / g or less, about 6.5 J / g or less, about 6.3 J / g or less, about 6.2 J / g or less, about 6.1 J / g or less, or about 6.0 J / g or less. Unsubstituted cross-linked pregelatinized starch may have an enthalpy of retrogradation of about 3.0 J / g or greater, about 3.5 J / g or greater, about 3.8 J / g or greater, or about 4.0 J / g or greater, as measured after 4 weeks of refrigerated storage. Unsubstituted cross-linked pregelatinized starch may have an enthalpy of retrogradation of about 3.0 J / g to about 7 J / g, about 3.5 J / g to about 6.7 J / g, or about 4.0 J / g to about 6.5 J / g, as measured after 4 weeks of refrigerated storage. In either case, unsubstituted cross-linked pregelatinized starch has an enthalpy of retrogradation of about 3 J / g or less, as measured after 1 week of storage, and an enthalpy of retrogradation of about 7 J / g or less, as measured after 4 weeks of refrigerated storage. In either case, the unsubstituted cross-linked pregelatinized starch has an enthalpy of retrogradation of about 2.5 J / g or less when stored for 1 week and about 6.5 J / g or less when refrigerated for 4 weeks. In any case, the unsubstituted cross-linked pregelatinized starch has an enthalpy of retrogradation of about 2.0 J / g or less when stored for 1 week and about 6.0 J / g or less when refrigerated for 4 weeks.

[0085] Unsubstituted cross-linked pregelatinized starch may have a retrogradation end temperature of about 90°C or lower, about 85°C or lower, about 80°C or lower, about 75°C or lower, or about 70°C or lower. The retrogradation end temperature may be about 50°C or higher.

[0086] According to any aspect of the invention, unsubstituted cross-linked pregelatinized starch exhibits good freeze-thaw stability. A freeze-thaw cycle is considered to be a combination of freeze-thaw cycles of a starch-containing composition, such as a food product. Starch can be stable in 2 or more, 3 or more, 4 or more, 5 or more, 6 or more, 8 or more, or 10 or more freeze-thaw cycles. While there may be no desired upper limit to the number of freeze-thaw cycles for starch stability, starch can be stable in up to 12 freeze-thaw cycles. In any aspect, starch is stable in 4 to 12 freeze-thaw cycles. Stability in freeze-thaw cycles can be visually assessed by observing whether any water separates from the product due to storage conditions, which may include one or more freeze-thaw cycles. If no water separation is observed on the surface or when the sample is pressed, the product is considered stable under the tested storage conditions.

[0087] In either case, the unsubstituted cross-linked pregelatinized starch has a cold viscosity (measured at neutral pH and 6% wt% solids) in the range of about 500 cP to about 3200 cP, an enthalpy of retrogradation of about 2.3 J / g or less at 1 week and about 7 J / g or less at 4 weeks, and a retrogradation end temperature of less than about 75 °C. In some cases, the unsubstituted cross-linked pregelatinized starch has a cold viscosity (measured at pH 3 and 5.5% wt% solids) in the range of about 1200 cP to about 3000 cP, an enthalpy of retrogradation of about 2.2 J / g or less at 1 week and about 6.8 J / g or less at 4 weeks, and a retrogradation end temperature of less than about 75 °C. In some cases, unsubstituted cross-linked pregelatinized starch has a cold viscosity (measured at neutral pH and about 6% wt% solids) in the range of about 1400 cP to about 2800 cP, a retrogradation enthalpy of about 2.1 J / g or less at 1 week and about 6.5 J / g or less at 4 weeks, and a retrogradation end temperature of less than about 75 °C.

[0088] Unsubstituted cross-linked pregelatinized starch can be prepared from any suitable waxy starch source. The term "native starch" is used herein to refer to the starch source from which unsubstituted cross-linked pregelatinized starch is prepared. Unsubstituted cross-linked pregelatinized starch can be prepared from native starch containing about 10% by weight or less, about 5% by weight or less, about 4% by weight or less, about 3% by weight or less, about 2% by weight or less, or about 1% by weight or less amylose. Native starch may contain no or substantially no amylose. In any case, unsubstituted cross-linked pregelatinized starch is prepared from waxy cassava, waxy rice, waxy sugar-2 maize mutant, short-chain waxy potato (identified by a combination of GBSS1 deficiency or nonfunctional GBSS1 with defective or nonfunctional SSII and / or SSIII enzymes), waxy wheat, hyperphosphorylated waxy starch, or any combination of two or more of these. In some embodiments, the unsubstituted cross-linked pregelatinized starch is prepared from a waxy sugar-2 maize mutant and has an enthalpy of retrogradation of 1.5 J / g or less when stored at 4°C for 1 week. In some such embodiments, the unsubstituted cross-linked pregelatinized starch has an enthalpy of retrogradation of 5 J / g or less when stored at 4°C for 4 weeks. Waxy sugar-2 is a double mutant maize plant in which the maize plant is homozygous or heterozygous recessive for the starch synthase IIa (su2) gene and homozygous or heterozygous for the mutant granule-binding starch synthase I (GBSSI) gene, wherein the mutant GBSSI gene has low activity or no GBSSI activity. Mutant maize plants with low GBSSI gene activity can produce less than about 10% amylose content, while those without GBSSI gene activity can produce less than about 2% or zero amylose content. In either embodiment, the unsubstituted cross-linked pregelatinized starch is prepared from waxy cassava starch. Waxy cassava starch can be obtained from naturally occurring waxy cassava plants or waxy cassava plants developed through non-genetically modified (non-GM) or conventional breeding. Waxy cassava starch can also be obtained from cassava plants modified using CRISPER / Cas9 technology. In either case, the unsubstituted cross-linked pregelatinized starch is prepared from highly phosphorylated waxy starch derived from potato, cassava, maize, wheat, rice, or any combination of two or more of these.

[0089] Uses of unsubstituted cross-linked starch

[0090] According to any aspect of the invention, unsubstituted cross-linked pregelatinized starch can be used in various ways to provide desired properties to a product. The uses described herein are applicable to any unsubstituted cross-linked pregelatinized starch, including unsubstituted cross-linked pregelatinized starch. Unsubstituted cross-linked pregelatinized starch can be formulated for use in food products, pet food products, or non-food products. Unsubstituted cross-linked pregelatinized starch can be used in food products, nutritional products, pharmaceutical products, personal care products, paper products, etc. In any aspect, unsubstituted cross-linked pregelatinized starch is formulated for human consumption.

[0091] Unsubstituted cross-linked pregelatinized starches can be used in food products to impart better refrigeration stability, heat stability, thickening, increased viscosity, or any combination of two or more of these. For example, unsubstituted cross-linked pregelatinized starches can be formulated for use in dairy products, dairy-based desserts, instant puddings, etc. Unsubstituted cross-linked pregelatinized starches can be formulated for use in non-dairy yogurts, non-dairy instant puddings, or other non-dairy desserts. Unsubstituted cross-linked pregelatinized starches can be formulated for mayonnaise, instant gravy, instant soups, sauces, dressings (spoonable or pourable), dips, spreads, instant toppings, baking fillings, pastry fillings, fruit mixtures, custards, icing mixtures, whipped toppings, creams, baking mixtures, pie fillings, dry mixes, etc. Unsubstituted cross-linked pregelatinized starches can be used in food products such as cereals, bread, bread products, cheese, cheese products, condiments, confectionery, sauces, pie fillings, sauces, cheese sauces, quick gravy, imitation syrups, quick puddings, custard, yogurt, sour cream and sour cream products, pasta, beverages, milk, soups, baby food, etc. Food products can be formulated for processing and storage conditions such as dry distillation, aseptic filling and packaging, refrigeration, freezing, or any combination of two or more of these.

[0092] Unreplaced cross-linked pregelatinized starch can be formulated for use in pet food, retort pouch food (e.g., retort pet food or any other food packaged in retort pouches), or canned pet food.

[0093] Unreplaced cross-linked pregelatinized starch can be used in paper products such as paper, paperboard, linerboard, corrugated board, cardboard, etc.

[0094] Unsubstituted cross-linked pregelatinized starch can be used in pharmaceutical or nutritional products as a binder, disintegrant, diluent, tablet, powder, etc. Unsubstituted cross-linked pregelatinized starch can also be used in personal care products such as deodorants, antiperspirants, hairsprays, gels, mousses, lotions, hair oils, soaps, detergents, shampoos, conditioners, mouthwashes, breath fresheners, toothpaste, and cosmetics such as eyeshadow, powder, foundation, blush, etc.

[0095] According to any aspect of this disclosure, the food product comprises unsubstituted cross-linked pregelatinized starch. The food product may be a food product for human consumption, pet food, or animal feed. The food product may be a dairy product, such as fruit blends, dairy-based desserts, instant puddings, instant cheeses, cream sauces, or combinations thereof. The food product may be a non-dairy yogurt or a non-dairy pudding. The food product may be a sauce, instant gravy, instant soup, sauce (spoonable or pourable), dip, spread, baking filling, pastry filling, fruit blend, custard, frosting mixture, whipped topping, cream, baking mix, pie filling, dry mix, etc. The food product may be pet food, retort pouch food, or canned pet food. Unsubstituted cross-linked pregelatinized starch may be used in the food product at any suitable concentration to achieve desired characteristics or quality affected by the presence of unsubstituted cross-linked pregelatinized starch. For example, unsubstituted cross-linked pregelatinized starch may be included based on the total weight of the food product in amounts of about 1% by weight or more, about 2% by weight or more, about 5% by weight or more, about 7.5% by weight or more, about 10% by weight or more, about 12.5% ​​by weight or more, about 15% by weight or more, or about 20% by weight or more. Unsubstituted cross-linked pregelatinized starch may be included based on the total weight of the food product in amounts of about 35% by weight or less, about 30% by weight or less, about 25% by weight or less, about 20% by weight or less, about 15% by weight or less, or about 10% by weight or less. In either case, unsubstituted cross-linked pregelatinized starch constitutes about 1% by weight to about 35% by weight, or about 5% by weight to about 25% by weight of the food product. In dry blends, such as those intended for use in sauces, ready meals, baked goods fillings, etc., starch content can be at the high end of this range, for example, from about 10% by weight to about 35% by weight or even higher, such as from about 10% by weight to about 50% by weight, from about 20% by weight to about 50% by weight, or from about 35% by weight to about 50% by weight. The primary function of starch in these applications is to thicken and produce a paste-like texture. For example, lower concentrations can be used in dairy beverages, such as fermented dairy beverages, acidified dairy beverages, or neutral dairy beverages and their alternatives. The amount of starch in such products can range from 0.2% by weight to about 6% by weight. In these applications, starch functions to provide body and enhance mouthfeel. In ready puddings, desserts, ready cheeses, and cream sauces, starch can be included at a concentration from about 1% by weight to about 10% by weight. In these applications, starch functions to bind water (providing thickening), provide texture, and help prevent dehydration shrinkage. In instant soups, sauces, gravy, scoopable or pourable sauces (whether emulsified or not), and sauce mixtures, starch may be contained at a concentration of about 1% by weight to about 10% by weight. In these applications, starch functions to bind water (providing thickening), viscosity, and texture.In ready-to-eat fruit fillings, cream fillings, frozen fillings, frosting mixtures, custards, and whipped toppings / meringoes, starch can be included at a concentration of from about 2% by weight to about 15% by weight. In these applications, starch functions to bind water (providing thickening), viscosity, and to provide a creamy texture, and to help prevent dehydration shrinkage.

[0096] Exemplary aspects

[0097] The following list provides various combinations of exemplary aspects and aspects according to this disclosure.

[0098] According to aspect 1, an unsubstituted crosslinked (e.g., crosslinked) starch, said unsubstituted crosslinked starch having a cold viscosity (measured at neutral pH and 6% wt% solids) in the range of about 500 cP to about 3200 cP, a retrogradation enthalpy of about 2.8 J / g or less at 1 week and about 7 J / g or less at 4 weeks, and a retrogradation end temperature of less than about 75°C.

[0099] Aspect 2 is the unsubstituted cross-linked pregelatinized starch according to aspect 1, wherein the unsubstituted cross-linked pregelatinized starch is prepared from waxy cassava, waxy rice, waxy sugar-2 corn mutant, short-chain waxy potato, waxy wheat, highly phosphorylated waxy starch, or any combination of two or more of them.

[0100] Aspect 2' is the unsubstituted cross-linked pregelatinized starch according to aspect 2, wherein the unsubstituted cross-linked pregelatinized starch is prepared from the wax sugar-2 corn mutant and has an enthalpy of retrogradation of 1.5 J / g or less when stored at 4°C for 1 week.

[0101] Aspect 2'' is the unsubstituted cross-linked pregelatinized starch according to aspect 2', wherein the unsubstituted cross-linked pregelatinized starch has an enthalpy of 5 J / g or less when stored at 4°C for 4 weeks.

[0102] Aspect 3 is the unsubstituted cross-linked pregelatinized starch according to aspect 1 or 2, wherein the starch is cross-linked.

[0103] Aspect 4 is an unsubstituted cross-linked pregelatinized starch according to any one of aspects 1 to 3, wherein the unsubstituted cross-linked pregelatinized starch includes unsubstituted cross-linked waxy tapioca starch.

[0104] Aspect 5 is an unsubstituted cross-linked pregelatinized starch according to any one of Aspects 1 to 4, wherein the unsubstituted cross-linked modified starch is prepared from waxy cassava starch cross-linked with the following substances: epichlorohydrin, linear dicarboxylic anhydride, citric acid, phosphorus oxychloride, adipic acid / adipate, trimetaphosphate, sodium trimetaphosphate, a mixture of sodium trimetaphosphate and sodium tripolyphosphate, linear dicarboxylic anhydride, adipic acid, formaldehyde, cyanuric chloride, diisocyanate, divinyl sulfone, or any two or more combinations thereof.

[0105] Aspect 6 is an unsubstituted cross-linked pregelatinized starch according to any one of Aspects 1 to 5, wherein the unsubstituted cross-linked pregelatinized starch is prepared from waxy cassava starch cross-linked using a cross-linking agent, the cross-linking agent including sodium trimetaphosphate, phosphorus oxychloride, adipic acid or adipic acid salt, epichlorohydrin or any combination of two or more of the above.

[0106] Aspect 7 is an unsubstituted cross-linked pregelatinized starch according to any one of Aspects 1 to 6, wherein the unsubstituted cross-linked pregelatinized starch is prepared from waxy cassava starch cross-linked using a cross-linking agent consisting of sodium trimetaphosphate, phosphorus oxychloride, or a combination thereof.

[0107] Aspect 8 is an unsubstituted cross-linked pregelatinized starch according to any one of Aspects 1 to 7, wherein the cold viscosity (measured at neutral pH and 6% by weight solids) is about 500 cP or greater, about 1000 cP or greater, about 1200 cP or greater, about 1400 cP or greater, about 1500 cP or greater, about 1600 cP or greater, about 1700 cP or greater, or about 1800 cP or greater.

[0108] Aspect 9 is an unsubstituted cross-linked pregelatinized starch according to any one of aspects 1 to 8, wherein the cold viscosity (measured at neutral pH and 6% by weight solids) is about 3200 cP or less, about 3100 cP or less, about 3000 cP or less, about 2900 cP or less, or about 2800 cP or less.

[0109] Aspect 10 is an unsubstituted cross-linked pregelatinized starch according to any one of aspects 1 to 9, wherein the cold viscosity (measured at neutral pH and 6% by weight solids) is in the range of about 500 cP to about 3200 cP, about 500 cP to about 3000 cP, about 1000 cP to about 3000 cP, about 1200 cP to about 2900 cP, about 1400 cP to about 2800 cP, about 1600 cP to about 2800 cP, or about 1800 cP to about 2600 cP.

[0110] Aspect 11 is an unsubstituted cross-linked pregelatinized starch according to any one of aspects 1 to 10, wherein the retrogradation enthalpy is about 2.5 J / g or less, about 2.4 J / g or less, about 2.3 J / g or less, about 2.2 J / g or less, about 2.1 J / g or less, or about 2.0 J / g or less, as measured after 1 week of refrigerated storage.

[0111] Aspect 12 is an unsubstituted cross-linked pregelatinized starch according to any one of aspects 1 to 11, wherein the retrogradation enthalpy is about 2.3 J / g or less when refrigerated for 1 week.

[0112] Aspect 13 is an unsubstituted cross-linked pregelatinized starch according to any one of aspects 1 to 12, wherein the retrogradation enthalpy is about 0.7 J / g or greater, about 0.8 J / g or greater, about 0.9 J / g or greater, or about 1.0 J / g or greater, as measured after 1 week of refrigerated storage.

[0113] Aspect 14 is an unsubstituted cross-linked pregelatinized starch according to any one of aspects 1 to 13, wherein the retrogradation enthalpy is about 6.7 J / g or less, about 6.5 J / g or less, about 6.3 J / g or less, about 6.2 J / g or less, about 6.1 J / g or less, or about 6.0 J / g or less, as measured after 4 weeks of refrigerated storage.

[0114] Aspect 15 is an unsubstituted crosslinked pregelatinized starch according to any one of aspects 1 to 14, wherein the unsubstituted crosslinked pregelatinized starch comprises about 10% or less, about 5% or less, about 3% or less, about 2% or less, about 1.5% or less of amylose, or contains no amylose.

[0115] Aspect 16 is an unsubstituted cross-linked pregelatinized starch according to any one of aspects 1 to 15, wherein the unsubstituted cross-linked pregelatinized starch is substantially free of amylose.

[0116] Aspect 17 is an unsubstituted cross-linked pregelatinized starch according to any one of aspects 1 to 16, wherein the unsubstituted cross-linked pregelatinized starch is prepared from waxy cassava starch, wherein the waxy cassava starch is prepared from cassava plants modified using CRISPER / Cas9 technology.

[0117] Aspect 18 is an unsubstituted cross-linked pregelatinized starch according to any one of Aspects 1 to 16, wherein the unsubstituted cross-linked pregelatinized starch is prepared from waxy cassava starch, wherein the waxy cassava starch is prepared from naturally occurring waxy cassava plants or waxy cassava plants developed through non-genetic modification or conventional breeding.

[0118] Aspect 19 is an unsubstituted cross-linked pregelatinized starch according to any one of aspects 1 to 18, wherein the starch is not hydroxypropylated or acetylated.

[0119] Aspect 20 is an unsubstituted cross-linked pregelatinized starch according to any one of aspects 1 to 19, wherein the starch is whole or fragmented.

[0120] Aspect 21 is an unsubstituted cross-linked pregelatinized starch according to any one of aspects 1 to 20, wherein the starch is a pregelatinized agglomerate product.

[0121] Aspect 22 is an unsubstituted cross-linked pregelatinized starch according to any one of aspects 1 to 21, wherein the starch is stable in two or more, three or more, four or more, five or more, six or more, eight or more, or ten or more freeze-thaw cycles.

[0122] Aspect 23 is an unsubstituted cross-linked pregelatinized starch according to any one of aspects 1 to 22, wherein the starch is stable in 2 to 12, 3 to 12, 4 to 12, 5 to 12, 6 to 12, 8 to 12 or 10 to 12 freeze-thaw cycles.

[0123] Aspect 24 is a food product comprising unsubstituted cross-linked pregelatinized starch according to any one of aspects 1 to 23.

[0124] Aspect 25 is a food product according to aspect 24, wherein the food product is a dairy product.

[0125] Aspect 26 is a food product according to aspect 25, wherein the dairy product includes fruit mixtures, dairy-based desserts, instant puddings, instant cheeses, cream sauces, or any two or more combinations thereof, preferably wherein the dairy product includes dairy-based desserts or instant puddings.

[0126] Aspect 27 is the food product according to aspect 24, wherein the food product is a non-dairy instant pudding.

[0127] Aspect 28 is the food product according to aspect 24, wherein the food product includes instant sauces, instant gravy, instant soup, sauces, dips, spreads, instant toppings, baking fillings, pastry fillings, fruit mixtures / instant fruit fillings, custard, frosting mixtures, whipped toppings / meringues, instant cream fillings, cake mixtures, baking mixtures, pie fillings, custard, or dry mixes.

[0128] Aspect 29 is the food product according to aspect 24, wherein the food product includes pet food, retort pouch food or canned pet food.

[0129] Aspect 30 is a food product according to any one of aspects 24 to 29, wherein the unsubstituted cross-linked pregelatinized starch accounts for about 1% to about 35% by weight, about 5% to about 25% by weight, about 10% to about 35% by weight, about 10% to about 50% by weight, about 20% to about 50% by weight, or about 35% to about 50% by weight of the food product.

[0130] Aspect 31 is a food product according to any one of aspects 24 to 30, wherein the food product includes dairy beverages, such as fermented dairy beverages, acidified dairy beverages or neutral dairy beverages, and the unsubstituted cross-linked pregelatinized starch accounts for about 0.2% to about 3% by weight of the food product.

[0131] Aspect 32 is a food product according to any one of Aspects 24 to 30, wherein the food product comprises fruit mixtures, dairy-based desserts, quick puddings, quick cheeses and cream sauces, and wherein the unsubstituted cross-linked pregelatinized starch comprises about 1% to about 10% by weight of the food product.

[0132] Aspect 33 is a food product according to any one of Aspects 24 to 30, wherein the food product includes instant sauces, instant gravy, instant soups, sauces, dips, spreads, instant toppings, baking fillings, pastry fillings, fruit mixtures / instant fruit fillings, custard, frosting mixtures, whipped toppings / meringues, instant cream fillings, cake mixtures, baking mixtures, pie fillings, custard, or dry mixes, and wherein the unsubstituted cross-linked pregelatinized starch comprises about 1% to about 15% by weight of the food product.

[0133] Aspect 34 is a food product according to any one of aspects 24 to 30, wherein the food product includes a ready-to-eat fruit filling, and the unsubstituted cross-linked pregelatinized starch accounts for about 2% to about 8% by weight of the food product.

[0134] Aspect 35 is a method for preparing unsubstituted cross-linked pregelatinized starch, the method comprising:

[0135] Native starch is mixed with water to form a slurry;

[0136] Adjust the pH of the slurry to alkaline;

[0137] The crosslinking agent is mixed with the slurry to achieve a crosslinking reaction; and

[0138] Pregelatinize unsubstituted cross-linked starch.

[0139] The resulting unsubstituted cross-linked pregelatinized starch exhibits a cold viscosity in the range of about 500 cP to about 3200 cP, a retrogradation enthalpy of about 2.8 J / g or less at 1 week and about 7 J / g or less at 4 weeks, and a retrogradation end temperature of less than about 75°C.

[0140] Aspect 36 is the method according to aspect 35, wherein the slurry contains about 45% by weight or less, about 40% by weight or less, or about 35% by weight or less of virgin starch dry solids based on the weight of the slurry.

[0141] Aspect 37 is the method according to aspect 35 or 36, wherein the slurry comprises about 20% to about 45% by weight, about 30% to about 45% by weight, or about 30% to about 40% by weight of virgin starch dry solids based on the weight of the slurry.

[0142] Aspect 38 is the method according to any one of aspects 35 to 37, wherein the pH is adjusted to a range of about 10 to about 13, or about 11 to about 12.

[0143] Aspect 39 is the method according to any one of aspects 35 to 38, wherein the crosslinking reaction includes a reaction temperature of about 25°C or higher, about 28°C or higher, or about 32°C or higher.

[0144] Aspect 40 is the method according to any one of aspects 35 to 39, wherein the crosslinking reaction includes a reaction temperature of about 60°C or lower, or about 50°C or lower.

[0145] Aspect 41 is the method according to any one of aspects 35 to 40, wherein the crosslinking reaction includes a reaction temperature of about 24°C to about 45°C.

[0146] Aspect 42 is the method according to any one of aspects 35 to 41, wherein the crosslinking reaction has a duration of about 15 min or longer, about 30 min or longer, about 60 min or longer, about 2 hours or longer, about 3 hours or longer, about 4 hours or longer, or about 5 hours or longer.

[0147] Aspect 43 is the method according to any one of aspects 35 to 42, wherein the crosslinking reaction has a duration of about 24 hours or less, about 18 hours or less, about 12 hours or less, about 10 hours or less, or about 8 hours or less.

[0148] Aspect 44 is the method according to any one of aspects 35 to 43, wherein the crosslinking reaction includes a holding time of about 10 min or longer, about 20 min or longer, about 30 min or longer, or about 45 min or longer.

[0149] Aspect 45 is the method according to any one of aspects 35 to 44, wherein the crosslinking reaction includes a holding time of up to about 24 hours, up to about 12 hours, up to about 6 hours, up to about 3 hours, up to about 2 hours, or up to about 1.5 hours.

[0150] Aspect 46 is the method according to any one of aspects 35 to 45, wherein the crosslinking reaction includes a duration of about 0.5 h to about 10 h and a retention time of about 10 min to about 2 h.

[0151] Aspect 47 is the method according to any one of Aspects 35 to 46, wherein the crosslinking agent comprises epichlorohydrin, linear dicarboxylic anhydride, phosphorus oxychloride, adipic acid / adipate, trimetaphosphate, sodium trimetaphosphate, a mixture of sodium trimetaphosphate and sodium tripolyphosphate, linear dicarboxylic anhydride, adipate, formaldehyde, cyanuric chloride, diisocyanate, divinyl sulfone, or any two or more combinations thereof.

[0152] Aspect 48 is the method according to any one of aspects 35 to 47, wherein the crosslinking agent comprises sodium trimetaphosphate, phosphorus oxychloride, adipate, epichlorohydrin, or any combination of two or more thereof.

[0153] Aspect 49 is the method according to any one of aspects 35 to 48, wherein the crosslinking agent consists of sodium trimetaphosphate, phosphorus oxychloride, or a combination thereof.

[0154] Aspect 50 is the method according to any one of aspects 35 to 49, wherein the crosslinking agent is contained in the slurry at a concentration of about 0.001% by weight to about 1.0% by weight or about 0.008% by weight to about 0.1% by weight based on dry weight.

[0155] Aspect 51 is the method according to any one of aspects 35 to 50, wherein the crosslinking agent is contained in the slurry at a concentration of about 0.5% by weight or less, about 0.4% by weight or less, about 0.25% by weight or less, or about 0.1% by weight or less based on dry weight.

[0156] Aspect 52 is the method according to any one of aspects 35 to 51, wherein the slurry contains about 0.5% by weight or more, about 1% by weight or more, about 2% by weight or more, about 3% by weight or more, or about 4% by weight or more salt.

[0157] Aspect 53 is the method according to any one of aspects 35 to 52, wherein the slurry contains about 10% by weight or less, about 8% by weight or less, about 7% by weight or less, or about 6% by weight or less salt.

[0158] Aspect 54 is the method according to any one of aspects 35 to 53, wherein the slurry contains about 0.5% by weight to about 10% by weight of salt.

[0159] Aspect 55 is the method according to any one of aspects 52 to 54, wherein the salt comprises sodium hydroxide (NaOH), potassium hydroxide (KOH), sodium carbonate (Na2CO3), potassium carbonate (K2CO3), or any combination of two or more thereof.

[0160] Aspect 56 is the method according to any one of aspects 35 to 55, the method further comprising adjusting the pH to a range of 4 to 7.5, 4.5 to 6.5, or 5 to 6 after crosslinking.

[0161] Aspect 57 is the method according to any one of aspects 35 to 56, the method further comprising dehydrating and drying the starch.

[0162] Aspect 58 is the method according to any one of aspects 35 to 57, wherein the native starch comprises waxy cassava, waxy rice, waxy sugar-2 corn mutant, short-chain waxy potato, waxy wheat, highly phosphorylated waxy starch, or any combination of two or more thereof.

[0163] Aspect 59 is the method according to any one of aspects 35 to 58, wherein the native starch comprises about 10% by weight or less, about 5% by weight or less, about 3% by weight or less, about 2% by weight or less, about 1.5% by weight or less, or 0% by weight of amylose.

[0164] Aspect 60 is the method according to any one of aspects 35 to 59, wherein the native starch contains no or substantially no amylose.

[0165] Aspect 61 is the method according to any one of aspects 35 to 60, wherein the unsubstituted cross-linked pregelatinized starch comprises unsubstituted cross-linked waxy tapioca starch.

[0166] Aspect 62 is the method according to any one of aspects 35 to 61, wherein the unsubstituted cross-linked pregelatinized starch exhibits a cold viscosity (measured at neutral pH and 6% wt) of about 500 cP or greater, about 1000 cP or greater, about 1200 cP or greater, about 1400 cP or greater, about 1500 cP or greater, about 1600 cP or greater, about 1700 cP or greater, or about 1800 cP or greater.

[0167] Aspect 63 is the method according to any one of aspects 35 to 62, wherein the unsubstituted cross-linked pregelatinized starch exhibits a cold viscosity of about 3200 cP or less, about 3100 cP or less, about 3000 cP or less, about 2900 cP or less, or about 2800 cP or less (measured at neutral pH and 6% wt% solids).

[0168] Aspect 64 is the method according to any one of aspects 35 to 63, wherein the unsubstituted cross-linked pregelatinized starch exhibits a cold viscosity (measured at neutral pH and 6% by weight) of about 500 cP to about 3200 cP, about 500 cP to about 3000 cP, about 1000 cP to about 3000 cP, about 1200 cP to about 2900 cP, about 1400 cP to about 2800 cP, about 1600 cP to about 2800 cP, or about 1800 cP to about 2600 cP.

[0169] Aspect 65 is the method according to any one of aspects 35 to 64, wherein the regeneration enthalpy is about 2.5 J / g or less, about 2.4 J / g or less, about 2.3 J / g or less, about 2.2 J / g or less, about 2.1 J / g or less, or about 2.0 J / g or less, as measured after 1 week of refrigerated storage.

[0170] Aspect 66 is the method according to any one of aspects 35 to 65, wherein the retrograde enthalpy is about 2.3 J / g or less, measured after 1 week of refrigerated storage.

[0171] Aspect 67 is the method according to any one of aspects 35 to 66, wherein the retrograde enthalpy is about 0.7 J / g or greater, about 0.8 J / g or greater, about 0.9 J / g or greater, or about 1.0 J / g or greater, as measured after 1 week of refrigerated storage.

[0172] Aspect 68 is the method according to any one of aspects 35 to 67, wherein the regeneration enthalpy is about 6.7 J / g or less, about 6.5 J / g or less, about 6.3 J / g or less, about 6.2 J / g or less, about 6.1 J / g or less, or about 6.0 J / g or less, as measured after 4 weeks of refrigerated storage.

[0173] Aspect 69 is the method according to any one of aspects 35 to 68, wherein the method does not include the substitution of the starch.

[0174] Aspect 70 is the method according to any one of aspects 35 to 69, wherein the method does not include hydroxypropylation or acetylation.

[0175] Aspect 71 is a nutritional product comprising unsubstituted cross-linked pregelatinized starch according to any one of aspects 1 to 23.

[0176] Aspect 72 is a pharmaceutical product comprising unsubstituted cross-linked pregelatinized starch according to any one of aspects 1 to 23.

[0177] Aspect 73 is a personal care product comprising unsubstituted cross-linked pregelatinized starch according to any one of aspects 1 to 23.

[0178] Aspect 74 is a paper article comprising unsubstituted cross-linked pregelatinized starch according to any one of aspects 1 to 23.

[0179] Aspect 75 is an unsubstituted cross-linked pregelatinized starch according to any one of aspects 1 to 23, said unsubstituted cross-linked pregelatinized starch having a cold viscosity (measured at neutral pH and 6% wt% solids) in the range of about 500 cP to about 3200 cP.

[0180] Aspect 76 is an unsubstituted crosslinked pregelatinized starch having a cold viscosity (measured at neutral pH and 6% wt% solids) in the range of about 500 cP to about 3200 cP.

[0181] Example

[0182] Example 1

[0183] The retrogradation behavior of various starch samples was tested. In this study, starch retrogradation was characterized by differential scanning calorimetry (DSC). Since enthalpy (ΔH) reflects the melting of the double helix, the enthalpy of retrograded starch reflects the degree of retrogradation. Samples were prepared by crosslinking native starch with different amounts of sodium trimetaphosphate (STMP) or phosphorus oxychloride (POCl3).

[0184] Sample preparation

[0185] Slurry preparation: An alkaline slurry of virgin starch (36 wt% dry solids) was prepared. Water, sodium hydroxide (NaOH), and sodium chloride (NaCl) were mixed using an overhead stirrer. Once the NaOH dissolved (0.52 wt%), sodium chloride (NaCl) was added at 1.5 wt% of the starch weight. The slurry was treated at 104℉ (40℃) with stirring while heating.

[0186] STMP crosslinking: Once the temperature reaches 105℉ (40.6℃), sodium trimetaphosphate (STMP) is added to the slurry. The amount of STMP ranges from 0.1% to 0.35% by weight. The reaction temperature is maintained for 8 hours. After the reaction, the pH of the slurry is adjusted to 5.5 with dilute hydrochloric acid (HCl). The starch is then dehydrated, washed, and dried.

[0187] Starch slurry (19 Baume) was prepared by mixing STMP-crosslinked starch into water. Spray cooking was performed using steam at 200°C and a steam pressure of 10-14 bar.

[0188] The viscosity of the samples was measured using a Rapid Viscosity Analyzer (RVA) model RVA4800 from PerkinElmer Inc., Waltham, MA. The cold viscosity of starch (6% by weight solids) was measured at neutral pH. The cold viscosity of the sample is the viscosity after 30 minutes at 30°C. It corresponds to the viscosity after a total run time of 34 minutes and 10 seconds.

[0189] The retrogradation parameters of the samples were measured using a TA Instruments Q2000 differential scanning calorimeter (DSC) (TA Instruments, General Analysis 2000) equipped with a thermal analysis data station and data logging software. The starch-to-water ratio was 1:3. The pregelatinized samples were stored in the DSC pan at 4°C for 1 and 4 weeks and scanned at 10°C / min from 5°C to 105°C. An empty aluminum pan was used as a reference for recording the thermograms in all measurements. The reported transition temperatures are the onset temperature (To), peak temperature (Tp), and end temperature (Tc). The retrogradation enthalpy (ΔH) was estimated by integrating the area between the thermogram and the baseline below the peak and is expressed in J / g dry starch. The retrogradation enthalpy results are shown in Table 3 below, and the cold viscosity results are shown in Table 4.

[0190]

[0191]

[0192] All references and publications cited herein are expressly incorporated in their entirety by way of citation, unless they may directly contradict this disclosure. Although specific embodiments have been illustrated and described herein, those skilled in the art will understand that various alternative and / or equivalent embodiments may be substituted for the specific embodiments shown and described without departing from the scope of this disclosure. It should be understood that this disclosure is not intended to be unduly limited by the illustrative embodiments and examples set forth herein, and such examples and embodiments are presented by way of example only, and the scope of this disclosure is intended to be limited solely by the claims set forth herein.

Claims

1. An unsubstituted crosslinked pregelatinized starch having a cold viscosity (measured at neutral pH and 6% wt% solids) in the range of about 500 cP to about 3200 cP and a retrogradation enthalpy of 2.5 J / g or less when stored at 4°C for 1 week.

2. The unsubstituted cross-linked pregelatinized starch according to claim 1, wherein the unsubstituted cross-linked pregelatinized starch is prepared from a wax sugar-2 corn mutant and has an enthalpy of retrogradation of 1.5 J / g or less when stored at 4°C for 1 week.

3. The unsubstituted crosslinked pregelatinized starch according to claim 2, wherein the unsubstituted crosslinked pregelatinized starch has an enthalpy of 5 J / g or less when stored at 4°C for 4 weeks.

4. The unsubstituted cross-linked pregelatinized starch according to claim 1, wherein the unsubstituted cross-linked pregelatinized starch is prepared from waxy cassava, waxy rice, waxy sugar-2 corn mutant, short-chain waxy potato, waxy wheat, highly phosphorylated waxy starch, or any combination of two or more thereof.

5. The unsubstituted crosslinked pregelatinized starch according to claim 1, wherein the unsubstituted crosslinked pregelatinized starch is crosslinked using a crosslinking agent, said crosslinking agent comprising sodium trimetaphosphate, phosphorus oxychloride, adipic acid salt, epichlorohydrin, or any combination of two or more thereof.

6. The unsubstituted crosslinked pregelatinized starch according to claim 1, wherein the unsubstituted crosslinked pregelatinized starch comprises 5% by weight or less amylose.

7. The unsubstituted cross-linked pregelatinized starch according to claim 1, wherein the starch is not hydroxypropylated or acetylated.

8. The unsubstituted cross-linked pregelatinized starch according to claim 1, wherein the starch is intact.

9. The unsubstituted cross-linked pregelatinized starch according to claim 1, wherein the starch is swollen in cold water.

10. The unsubstituted cross-linked pregelatinized starch according to claim 1, wherein the starch is stable in four or more freeze-thaw cycles.

11. An unsubstituted crosslinked pregelatinized starch having a cold viscosity (measured at neutral pH and 6% wt% solids) in the range of about 500 cP to about 3200 cP, a retrogradation enthalpy of 2.3 J / g or less at 1 week and 7 J / g or less at 4 weeks, and a retrogradation end temperature of less than 75°C.

12. A food product comprising unsubstituted cross-linked pregelatinized starch according to any one of claims 1 to 11.

13. A food product comprising unsubstituted cross-linked pregelatinized starch according to any one of claims 1 to 12, wherein the food product comprises instant sauces, instant gravy, instant soups, sauces, dips, spreads, instant toppings, baking fillings, pastry fillings, fruit mixtures / instant fruit fillings, custard, frosting mixtures, whipped toppings / meringues, instant cream fillings, cake mixtures, baking mixtures, pie fillings, custards, or dry mixes or combinations thereof.

14. A food product comprising unsubstituted cross-linked pregelatinized starch according to any one of claims 1 to 12, wherein the food product is a dairy product, wherein the dairy product comprises fruit blends, dairy-based desserts, instant puddings, instant cheeses and cream sauces, or any two or more combinations thereof.

15. A method for preparing unsubstituted cross-linked pregelatinized starch, the method comprising: Native starch is mixed with water to form a slurry; Adjust the pH of the slurry to alkaline; The crosslinking agent is mixed with the slurry to achieve a crosslinking reaction; as well as To gelatinize cross-linked starch, The resulting unsubstituted cross-linked pregelatinized starch exhibited a cold viscosity (measured at neutral pH and 6% wt% solids) in the range of about 500 cP to about 3200 cP, a retrogradation enthalpy of 2.3 J / g or less at 1 week and 7 J / g or less at 4 weeks, and a retrogradation end temperature of less than 75 °C.

16. The method of claim 15, wherein the retrogradation enthalpy measured after storage at 4°C for 1 week is 2.3 J / g or less.

17. The method according to any one of claims 15 to 16, wherein the crosslinking reaction comprises a reaction temperature of about 24°C to about 45°C and a duration of about 0.5 h to about 10 h.

18. The method according to any one of claims 15 to 17, wherein the crosslinking agent comprises sodium trimetaphosphate, phosphorus oxychloride, adipic acid, adipate, epichlorohydrin, or any combination of two or more thereof.

19. The method according to any one of claims 15 to 18, wherein the native starch comprises waxy cassava, waxy rice, waxy sugar-2 corn mutant, short-chain waxy potato, waxy wheat, highly phosphorylated waxy starch, or any combination of two or more thereof.

20. The method according to any one of claims 15 to 19, wherein the unsubstituted cross-linked pregelatinized starch exhibits a cold viscosity in the range of about 800 cP to about 3000 cP.

21. The method according to any one of claims 15 to 20, wherein the method does not include hydroxypropylation or acetylation.

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