Stabilized waxy starch and methods of use thereof

Abstract

The present invention relates to a stable waxy starch and methods of use thereof. One aspect of the invention is a corn, wheat or cassava based stable waxy starch having an amylopectin content of 90-100%; a sedimentation volume of 10-50 mL / g; wherein the amylopectin fraction of the corn, wheat or cassava based stable waxy starch has no more than 48.5% medium length branches having a chain length of 13-24 (as measured by the valley- valley method as described herein), and the starch is not pregelatinized. Methods of using the starch material in food products are also described.

Description

[0001] Divisional application

[0002] This invention is a divisional application of Chinese invention patent application filed on December 15, 2017, with application number 201780086459.X and title "Stable waxy starch and its application method". Technical Field

[0003] This invention generally relates to starch products. More specifically, this invention relates to stabilized waxy starch and related methods, including methods of use. Background Technology

[0004] Unlike non-wax starches, which are a mixture of amylopectin and amylose, wax starches are starches with a higher percentage of polysaccharides in the form of amylopectin. Wax starches can impart many desirable properties to a variety of foods. For example, wax starches such as waxed corn starch and waxed tapioca starch can give foods the desired texture and thickness, such as fillings for baked goods (e.g., fruit fillings for pies), batters, breads, sauces (e.g., cheese sauces), and gravy. Wax starches generally produce a higher viscosity than their corresponding non-wax starches.

[0005] However, natural starches typically cannot withstand the extreme conditions encountered during food processing, such as high temperatures and high shear stresses. Furthermore, natural waxy starches often fail to maintain ideal texture and rheological stability after long-term storage, especially under refrigeration and / or freeze-thaw conditions. Producing food-grade starches with ideal stability usually requires chemical modification to generate hydroxypropyl starch or acetylated starch. However, chemical modification requires additional processing steps and costs, and more importantly, consumers may not like this approach. Summary of the Invention

[0006] One aspect of the invention is a stable waxy starch based on corn, wheat, or cassava, having an amylopectin content of 90-100% and a sedimentation volume of 10-50 mL / g; wherein the amylopectin fraction of the stable waxy starch based on corn, wheat, or cassava has no more than 48.5% of medium-length branches with a chain length of 13-24 (i.e., the degree of polymerization of the branches), as determined by the grain-to-grain method (as described herein), and the starch is not pre-gelatinized. For example, in some embodiments, the amylopectin fraction of the stable waxy starch based on corn, wheat, or cassava has no more than 48.0% of medium-length branches with a chain length of 13-24, as determined by the grain-to-grain method. In some embodiments, the amylopectin fraction of stable waxy starch based on corn, wheat, or cassava has 46.0%-48.5%, 46.5%-48.5%, 47.0%-48.5%, 46.0%-48.0%, 46.5%-48.0%, or 47.0%-48.0% of medium-length branches with a chain length of 13-24, as determined by the gluten-gluten method.

[0007] Another aspect of the invention is a stable waxy starch based on corn, wheat, or cassava, as otherwise described herein, having an amylopectin content of 90-100% and a sedimentation volume of 10-50 mL / g; wherein the amylopectin fraction of the stable waxy starch based on corn, wheat, or cassava has at least 28.0% short branches with a chain length of 6-12, as determined by the grain-to-grain method (as described herein), and the starch is not pregelatinized. For example, in some embodiments, the amylopectin fraction of the stable waxy starch based on corn, wheat, or cassava has at least 28.5% short branches with a chain length of 6-12, as determined by the grain-to-grain method. In some embodiments, the amylopectin fraction of stable waxy starch based on corn, wheat, or cassava has 28.0%-31.0%, 28.0%-30.5%, 28.0%-30.0%, 28.5%-31.0%, 28.5%-30.5%, or 28.5%-30.0% short branches with a chain length of 6-12, as determined by the gluten-gluten method.

[0008] Another aspect of the invention is a stable waxy starch based on corn, wheat, or cassava, as otherwise described herein, having an amylopectin content of 90-100%; a sedimentation volume of 10-50 mL / g; wherein the ratio (DP13-24-DP6-12) / (DP13-24+DP6-12) as determined by the grain-to-grain method does not exceed 25.5%, wherein DP13-24 is the amount of medium-length branches with a chain length of 13-24 in the amylopectin portion of the stable waxy starch based on corn, wheat, or cassava, and DP6-12 is the amount of short branches with a chain length of 6-12 in the amylopectin portion of the stable waxy starch based on corn, wheat, or cassava (both measured as described herein), and the starch is not pre-gelatinized. For example, in some embodiments, the ratio (DP13-24-DP6-12) / (DP13-24+DP6-12) as determined by the grain-to-grain method does not exceed 25.0%, or even 24.5%. In some embodiments, the ratio (DP13-24-DP6-12) / (DP13-24+DP6-12) measured by the valley-valley method is 22.0%-25.5%, 22.0%-25.0%, 22.0%-24.5%, 22.5%-25.5%, 22.5%-25.0%, 22.5%-24.5%, 23.0%-25.5%, 23.0%-25.0%, or 23.0%-24.5%.

[0009] Another aspect of the invention is a stable waxy starch based on corn, wheat, or cassava, having an amylopectin content of 90-100% and a sedimentation volume of 10-50 mL / g; wherein the amylopectin fraction of the stable waxy starch based on corn, wheat, or cassava has no more than 54.5% of medium-length branches with a chain length of 13-24 (i.e., the degree of polymerization of the branches), as determined by the baseline method (as described herein), and the starch is not pregelatinized. For example, in some embodiments, the amylopectin fraction of the stable waxy starch based on corn, wheat, or cassava has no more than 54.0% of medium-length branches with a chain length of 13-24, as determined by the baseline method. In some embodiments, the amylopectin fraction of stable waxy starch based on corn, wheat, or cassava has 52.0%-54.5%, 52.5%-54.5%, 53.0%-54.5%, 52.0%-54.0%, 52.5%-54.0%, or 53.0%-54.0% of medium-length branches with a chain length of 13-24, as measured by the baseline method.

[0010] Another aspect of the invention is a stable waxy starch based on corn, wheat, or cassava, as otherwise described herein, having an amylopectin content of 90-100% and a sedimentation volume of 10-50 mL / g; wherein the amylopectin fraction of the stable waxy starch based on corn, wheat, or cassava has at least 30.5% short branches with a chain length of 6-12, as determined by a baseline reduction method (as described herein), and the starch is not pregelatinized. For example, in some embodiments, the amylopectin fraction of the stable waxy starch based on corn, wheat, or cassava has at least 31.0% short branches with a chain length of 6-12, as determined by a baseline reduction method. In some embodiments, the amylopectin fraction of stable waxy starch based on corn, wheat, or cassava has 30.5%-33.5%, 30.5%-33.0%, 30.5%-32.5%, 31.0%-33.5%, 31.0%-33.0%, or 31.0%-32.5% short branches with chain lengths of 6-12, as determined by the baseline method.

[0011] Another aspect of the invention is a stable waxy starch based on corn, wheat, or cassava, as otherwise described herein, having an amylopectin content of 90-100%; a sedimentation volume of 10-50 mL / g; wherein the ratio (DP13-24-DP6-12) / (DP13-24+DP6-12) as measured by the baseline method does not exceed 28.0%, wherein DP13-24 is the amount of medium-length branches with a chain length of 13-24 in the amylopectin portion of the stable waxy starch based on corn, wheat, or cassava, and DP6-12 is the amount of short branches with a chain length of 6-12 in the amylopectin portion of the stable waxy starch based on corn, wheat, or cassava (both measured as described herein), and the starch is not pre-gelled. For example, in some embodiments, the ratio (DP13-24-DP6-12) / (DP13-24+DP6-12) as measured by the baseline method does not exceed 27.5%, or even 27.0%. In some embodiments, the ratio (DP13-24-DP6-12) / (DP13-24+DP6-12) measured by the baseline method is 24.5%-28.0%, 24.5%-27.5%, 24.5%-27.0%, 25.0%-28.0%, 25.0%-27.5%, 25.0%-27.0%, 25.5%-28.0%, 25.5%-27.5%, and 25.5%-27.0%.

[0012] Another aspect of the present invention is a stabilized waxy cassava starch having an amylopectin content of 90-100% and a sedimentation volume of 10-50 mL / g. In the amylopectin fraction of the stabilized waxy cassava starch, the number of medium-length branches with a chain length of 13-24 is significantly greater than that of natural waxy rice starch, but significantly less than that of natural waxy corn starch, and the starch is not pre-gelatinized. For example, in some embodiments, the DP13-24 value of the amylopectin fraction of the stabilized waxy cassava starch is at least 2 percentage points, or at least 3 percentage points, or even at least 4 percentage points greater than that of natural waxy rice starch. In some embodiments, the DP13-24 value of the amylopectin fraction of the stabilized waxy cassava starch is at least 2 percentage points, or even at least 3 percentage points lower than that of natural waxy corn starch. In some embodiments, the branch length is measured by the grain-to-grain method. In other embodiments, the branch length is measured by the baseline method. Attached Figure Description

[0013] Figure 1 This is a comparison chart of the DP13-24 scores of the exemplary starch of the present invention and conventional starch, measured by the grain-to-grain method.

[0014] Figure 2This is a comparison chart of the exemplary starch of the present invention and conventional starch ratio (DP13-24-DP6-12) / (DP13-24+DP6-12) obtained by the grain-to-grain method.

[0015] Figure 3 It is the standard opacity photograph used in the experiment described in the example.

[0016] Figure 4 This is a schematic diagram of the dehydration shrinkage experiment conducted in the example.

[0017] Figure 5 These are a set of standard particle size photographs used in the experiment described in the example.

[0018] Figure 6-8 This is a set of bar charts showing the average values ​​of opacity, dehydration shrinkage, and particle size over the time course of the freeze-thaw experiment described in the example.

[0019] Figure 9 This is a graph showing the relationship between the change in hardness after three freeze-thaw cycles and the ratio (DP13-24-DP6-12) / (DP13-24+DP6-12) measured by the valley method in the experiment described in the example. Detailed Implementation

[0020] The inventors have determined that starches possessing this property (and, in some embodiments, other properties described herein) are particularly useful because they are suppressed and possess the desired stability properties without needing to be labeled as “modified” starches. For example, the starches of the present invention can provide ideal freeze-thaw stability, ideal refrigeration stability, and / or ideal storage stability.

[0021] Those skilled in the art will understand that the relative amounts of the two main starch polysaccharide components differ in various natural starches: amylose (linearly linked by α-(1,4) glycosidic bonds) and amylopectin (linked by α-1,6-glycosidic bonds in addition to α-1,4-glycosidic bonds). So-called "waxy" starches have at least 90% amylopectin (i.e., 90% of the total amount of amylose and amylopectin). Typical non-waxy starches have an amylopectin content of 70-85%. In some embodiments, the stabilized waxy starches based on corn, wheat, or cassava, also described herein, have an amylopectin content of 95-100%. In other embodiments, the stabilized waxy starches based on corn, wheat, or cassava, also described herein, have an amylopectin content of at least 99% or at least 99.9%. High amylopectin content gives waxy starches different properties from non-waxy starches, such as higher viscosity, the ability to form longer, thicker pastes, and higher anti-coagulation properties.

[0022] In some embodiments of stabilized waxy starch based on corn, wheat, or cassava described herein, the stabilized waxy starch is waxy cassava starch. In other embodiments of stabilized waxy starch based on corn, wheat, or cassava described herein, the stabilized waxy starch is waxy corn starch. In some embodiments of stabilized waxy starch based on corn, wheat, or cassava described herein, the stabilized waxy starch is waxy wheat starch. Those skilled in the art will be able to distinguish different starch sources, for example, by microscopy and comparison with standards. Those skilled in the art can, for example, observe starch materials under a microscope, optionally, stain with iodide, and determine the type of starch by the size and shape of the observed particles. As those skilled in the art will understand, different types of starch from different sources can have different textures and rheological properties, and are therefore suitable for different food applications.

[0023] The present invention relates to stabilized waxy starches based on corn, wheat, or cassava, which can have various sedimentation volumes in the range of 10-50 mL / g. For example, in some embodiments, stabilized waxy starches based on corn, wheat, or cassava, as additionally disclosed herein, have a sedimentation volume of 15-40 mL / g. In other embodiments, stabilized waxy starches based on corn, wheat, or cassava, as additionally disclosed herein, have a sedimentation volume of 18-35 mL / g. In several other embodiments, stabilized waxy starches based on corn, wheat, or cassava, as additionally disclosed herein, have sedimentation volumes of 10-40 mL / g, 10-35 mL / g, 15-50 mL / g, 15-35 mL / g, 18-50 mL / g, and 18-40 mL / g. In other embodiments, the stabilized waxy starches based on corn, wheat, or cassava disclosed herein have concentrations of 10-45 mL / g, 10-30 mL / g, 10-25 mL / g, 10-20 mL / g, 15-45 mL / g, 15-30 mL / g, 15-25 mL / g, 15-20 mL / g, 20-50 mL / g, 20-45 mL / g, 20-40 mL / g, and 20-35 mL / g. Sedimentation volumes of 20-30 mL / g, 20-25 mL / g, 25-50 mL / g, 25-45 mL / g, 25-40 mL / g, 25-35 mL / g, 25-30 mL / g, 30-50 mL / g, 30-45 mL / g, 30-40 mL / g, 30-35 mL / g, 35-50 mL / g, 35-45 mL / g, 35-40 mL / g, or 40-50 mL / g. Those skilled in the art will understand that sedimentation volume is a measure of the degree of starch inhibition and that a suitable range of sedimentation volumes will be selected based on the specific end use of the stable waxy starch based on corn, wheat, or cassava as described herein.

[0024] As used herein, sedimentation volume is the volume occupied by 1 g of cooked starch (dry basis) in 100 g (i.e., the total amount including starch) of salt buffer solution. This value is also referred to in the art as “expansion volume”. As used herein, “salt buffer solution” refers to a solution prepared according to the following steps:

[0025] (a) Using a top-loaded balance, weigh out 20g of sodium chloride and put it into a 2L volumetric flask equipped with a stir bar;

[0026] (b) Add RVA pH 6.5 buffer (purchased from Ricca Chemicals) to the volumetric flask until it is at least half full;

[0027] (c) Stir and mix until sodium chloride dissolves;

[0028] (d) Add more RVA pH 6.5 buffer to a final volume of 2L;

[0029] The sedimentation volume described in this article is determined as follows: First, the container containing the slurry is suspended in a 95°C water bath and stirred for 6 minutes with a glass rod or metal spatula. Then, the container is covered, and the slurry is kept at 95°C for another 20 minutes, thus cooking the starch in a salt buffer solution with a 5% solids content. The container is removed from the water bath and placed on a workbench to cool. The resulting slurry is restored to its initial weight by adding water (to replace the evaporated water) and thoroughly mixed. 20.0 g of the slurry (containing 1.0 g of starch) is weighed and placed in a 100 mL graduated cylinder containing a salt buffer solution. The total weight of the mixture in the graduated cylinder is brought to 100 g using the buffer solution. The graduated cylinder is allowed to stand for 24 hours. The volume occupied by the starch precipitate (i.e., the volume read in the cylinder) is the sedimentation volume of 1 g of starch, expressed in mL / g.

[0030] The inventors have determined that stable waxy starches based on corn, wheat, or cassava with a specific branch length distribution can provide particularly desirable properties. Therefore, in certain stable waxy starches based on corn, wheat, or cassava of the present invention, the amylopectin fraction has less than 48.5% of medium-length branches with a chain length of 13-24, and / or at least 28% of short branches with a chain length of 6-12, and / or a ratio (DP13-24-DP6-12) / (DP13-24+DP6-12) less than 25.5%, all of which were determined by the grain-to-grain method described herein.

[0031] The inventors have also determined that stable waxy starches based on corn, wheat, or cassava with a specific branch length distribution can provide particularly desirable properties. Therefore, in certain stable waxy starches based on corn, wheat, or cassava of the present invention, the amylopectin fraction has less than 54.5% of medium-length branches with a chain length of 13-24, and / or at least 30.5% of short branches with a chain length of 6-12, and / or a ratio (DP13-24-DP6-12) / (DP13-24+DP6-12) less than 28.0%, all of which were determined by the baseline reduction method described herein.

[0032] The inventors have also determined that stable waxy starches based on cassava with a specific branch length distribution can provide particularly desirable properties. Therefore, in certain stable waxy cassava starches of the present invention, the amylopectin fraction contains significantly more medium-length branches of 13-24 chain length than natural waxy rice starch, but significantly fewer medium-length branches of 13-24 chain length than natural waxy corn starch. As used herein, “natural waxy corn starch” is starch derived from the endosperm of waxy corn plants that does not contain the recessive su2 allele, as described in U.S. Patent No. 5,954,883, the entire contents of which are incorporated herein by reference. As used herein, natural waxy rice starch is natural waxy rice starch derived from waxy rice varieties, such as Taichung Waxy No. 1, Taichung Waxy No. 70, Tachimemochi, and Tainong Waxy No. 2. In some embodiments, the DP13-24 value of the stabilized waxy cassava starch of the present invention is at least 2 percentage points, or at least 3 percentage points, or even at least 4 percentage points higher than the DP13-24 value of natural waxy rice starch. In some embodiments, the DP13-24 value of the stabilized waxy cassava starch of the present invention is at least 2 percentage points, or even at least 3 percentage points lower than the DP13-24 value of natural waxy corn starch. Comparing the DP13-24 value of the stabilized waxy cassava starch of the present invention with the DP13-24 values ​​of comparative waxy rice and corn starch is an alternative method for determining certain desired starches. It is worth noting that certain measurement artifacts can be controlled during the comparison. In some of the embodiments described herein, the chain length is determined by the grain-to-grain method described herein. In other embodiments described herein, the chain length is determined by the baseline reduction method described herein.

[0033] This starch can have a non-sticky, smooth texture when cooked or gelled, and can exhibit tolerance to processing conditions (such as heat, shear and / or extreme pH) and rheological and texture stability during the desired shelf life, even under refrigeration and / or freeze-thaw conditions.

[0034] In the grain-grain method, the branch length of the amylopectin fraction is measured by first thoroughly debranching the amylopectin for 16 hours using isoamylase (EC 3.2.1.68, *Pseudomonas* spp., with isoamylase activity of 240 U / mg for oyster glycogen, α-amylase activity of less than 0.001 U / mg for reducing maltheptaose, maltase activity of less than 0.001 U / mg for maltose, and exo-α-glucanase activity of less than 0.00001 U / mg for linear α-1,4-maltodextrin) at pH 4.0 and 45°C. Fresh (i.e., stored at 4°C for no more than 5 days) 100 mM pH 4.0 acetic acid solution is used for debranching. Isoamylase can be purchased from Megazyme (Wicklow, Ireland). Specifically, debranching is performed as follows:

[0035] 1. Weigh 10 mg of waxy starch and place it at the bottom of a glass test tube (Fisher, #14-962-26G). Add 3 mL of Milli-Q water, cover the test tube, and prepare two samples.

[0036] 2. Heat the test tube for 1 hour, and rotate the sample intermittently in boiling water;

[0037] 3. Cool the test tube to room temperature, add 2 mL of pH 4.0 acetate buffer, and mix well;

[0038] 4. Add 10 μL of isoamylase (5 U) and a star-shaped stir bar to each test tube, mix well and cover;

[0039] 5. Incubate the sample in a 45°C heating block with continuous stirring for at least 16 hours;

[0040] 6. Heat the sample at 100℃ for 30 minutes to inactivate the enzyme;

[0041] 7. Cool the sample to 40°C and filter it through a 0.45μm organic phase nylon needle filter into an automated sampling bottle.

[0042] Debranched waxy starch was characterized by HPAE-PAD (high performance anion exchange chromatography with pulsed amperometric detection) on a Dionex ICS-3000 (Dionex Corporation, Sunnyvale, California). Dionex CarboPac PA1 analytical columns (4 x 250 mm) were used with CarboPac PA2 guard columns (4 x 50 mm). The eluents for separation were 150 mM NaOH (eluent A) and 150 mM NaOH containing 500 mM NaOAc (eluent B), prepared in degassed 18 MΩ·cm water and then filtered through a 0.2 μm membrane filter. The separation gradient program was as follows: 0–5 min 60% A, 5–20 min 60%–40% A, 20–50 min 40%–20% A, 50–55 min 20% A. As will be understood by those skilled in the art, "60% A" refers to a mixture of 60% eluent A and 40% eluent B. The sample solution injection volume is 10 μL. Each step is performed at 30°C and a flow rate of 1.2 mL / min. The working electrode is gold, and the reference electrode is silver / silver chloride. The waveform is a "gold standard PAD". Column equilibration and regeneration are as follows: the system is equilibrated with 100% A for 30 minutes before injection, then equilibrated with 60% A for at least 30 minutes. Every five injections, the column is regenerated with 100% A for 30 minutes, then equilibrated with 60% A for 30 minutes, and the residence time is checked with 5 ppm DP1-7 mixed standard solution. Sugar standards with a degree of polymerization of 1-7 can be purchased from, for example, Sigma-Aldrich.

[0043] To analyze the data in the valley-valley analysis method, peak area is calculated by integrating the peaks using the valley-valley method. Chain length distribution is expressed as a percentage of the total peak area between DP6 and DP53, with negligible variation in detector response with DP. The chain length distribution between DP6 and DP12 is summarized as "DP6-12"; the chain length distribution between DP13 and DP24 is summarized as "DP13-24". The %RSD for DP6-12 and DP13-24 in three parallel determinations should be less than 2%.

[0044] To analyze data from the baseline analysis method, starch samples (20 mg, dry basis) were mixed with 10 mL of acetate buffer (0.01 M, pH 4) and then boiled in a water bath for 1 hour. After cooling to 50°C, 20 μL of isoamylase (Megazyme, Wicklow, Ireland) was added to debranch the gelled starch. Debranching of starch can be performed overnight (≥12 hours), followed by enzyme inactivation by heating the sample in a water bath for 30 minutes. After cooling to room temperature, 1–1.5 mL of sample was passed through a 45 μm filter and then injected into an HPAEC AS-DV autosampler (Dionex ICS-3000, Sunnyvale, .C., equipped with a pulsed amperometric detector and CarboPac). TM PA1 analytical column. Samples were eluted using the following gradient program: 0 min 40% eluent B, 2 min 50%, 10 min 60%, 40 min 80%; where eluent A was a 100 mM sodium hydroxide aqueous solution, and eluent B was a 150 mM sodium hydroxide aqueous solution containing 500 mM sodium acetate. Throughout the measurement, the flow rate and separation temperature were maintained at 1 mL / min and 25 °C, respectively. Peaks were determined according to Chromeleon... TM The baseline was automatically created and integrated using 6.8 (Thermo Fisher Scientific, Waltham, Massachusetts). The relative area percentage for each detectable peak (DP) refers to the percentage of the area of ​​each peak in the chromatogram relative to the total area of ​​all peaks, as defined by Chromeleon. TM The calculations yielded the following results. Similarly, the chain length distribution is expressed as a percentage of the total peak area between DP6 and DP53, with negligible variations in detector response with DP. The chain length distribution between DP6 and DP12 is summarized as "DP6-12"; the chain length distribution between DP13 and DP24 is summarized as "DP13-24". Peaks were identified using the standards of Sigma-Aldrich, St. Louis, Missouri.

[0045] Those skilled in the art will understand that the branch length distribution of the amylopectin fraction in a waxy starch feedstock used to manufacture stable waxy starches based on corn, wheat, or cassava can be substantially reflected in the branch length distribution of the amylopectin fraction in stable waxy starches based on corn, wheat, or cassava. In the various methods for preparing stable waxy starches based on corn, wheat, or cassava as described herein, the process conditions do not significantly alter the branch length distribution of the amylopectin fraction. In some embodiments, for example, when certain waxy cassava starches are used as feedstocks, the waxy starch feedstock will have the desired medium-length branch distribution as described above. However, in other embodiments, for example, when certain waxy corn or waxy wheat starches are used as feedstocks, the waxy starch feedstock can be treated to reduce the relative amount of medium-length branches with a chain length of 13-24 and / or increase the relative amount of short branches with a chain length of 6-12. This treatment can be carried out, for example, using enzymatic methods.

[0046] The stabilized waxy starches based on corn, wheat, or cassava described herein can have a relatively light color. For example, some embodiments of stabilized waxy starches based on corn, wheat, or cassava described herein have a relatively light color, i.e., a yellow index not exceeding 10, for example, in the range of 3-10 or 5-10. In some desired embodiments, the starches described herein have a particularly light color, i.e., a yellow index less than 8 (e.g., 3-8 or 5-8). The yellow index is determined by ASTM E313.

[0047] It is worth noting that the corn, wheat, or cassava-based stable waxy starches described herein can be prepared without many of the conventional chemical modifiers used in the preparation of conventionally modified and / or stabilized starches. Therefore, in some desired embodiments, the corn, wheat, or cassava-based stable waxy starches additionally described herein can be labeled as so-called "clean label" starches. For example, in some embodiments, the corn, wheat, or cassava-based stable waxy starches additionally described herein are not hydroxypropylated. In some embodiments, the corn, wheat, or cassava-based stable waxy starches additionally described herein are not acetylated. In some embodiments, the corn, wheat, or cassava-based stable waxy starches additionally described herein are not carboxymethylated. In some embodiments, the corn, wheat, or cassava-based stable waxy starches additionally described herein are not hydroxyethylated. In some embodiments, the corn, wheat, or cassava-based stable waxy starches additionally described herein are not phosphorylated. In some embodiments, the corn, wheat, or cassava-based stable waxy starches additionally described herein are not succinylated (e.g., not octenyl succinylated). In some embodiments, the stable waxy starches based on corn, wheat, or cassava described herein are not cationic or zwitterionic.

[0048] Similarly, in some embodiments, the corn, wheat, or cassava-based stable waxy starches described herein can be prepared without the use of crosslinking agents typically used to inhibit starch crosslinking. For example, in some embodiments, the corn, wheat, or cassava-based stable waxy starches additionally described herein are not crosslinked with phosphates (e.g., using phosphorus oxychloride or metaphosphate). In some embodiments, the corn, wheat, or cassava-based stable waxy starches additionally described herein are not crosslinked with adipate esters. In some embodiments, the corn, wheat, or cassava-based stable waxy starches additionally described herein are not crosslinked with epichlorohydrin. In some embodiments, the corn, wheat, or cassava-based stable waxy starches additionally described herein are not crosslinked with acrolein.

[0049] The present invention relates to stabilized waxy starches based on corn, wheat, or cassava (e.g., having the aforementioned yellow value), which in some embodiments can be prepared without the use of other harsh chemical treatments common in the art. For example, in some embodiments, the stabilized waxy starches based on corn, wheat, or cassava, as additionally described herein, are not bleached or oxidized with peroxides or hypochlorites. Of course, in other embodiments, peroxides or hypochlorites can be used to give the stabilized waxy starches based on corn, wheat, or cassava described herein a better color.

[0050] In some embodiments, the corn, wheat, or cassava-based stable waxy starches of the present invention can be prepared without dextrinization and therefore do not contain a significant amount of the repolymerized branches characteristic of dextrin. Thus, in such embodiments, the corn, wheat, or cassava-based stable waxy starches also described herein are substantially lacking in 1,2- and 1,3-branching (e.g., less than 1% of each). Such branching can be determined using nuclear magnetic resonance (NMR) techniques familiar to those skilled in the art.

[0051] The stable waxy starches based on corn, wheat, or cassava of the present invention can have various viscosities, as measured by a rapid viscosity analyzer (RVA). For example, in some embodiments, the stable waxy starches based on corn, wheat, or cassava, further described herein, can have viscosities of 50-1500 cP, as measured by RVA. In some such embodiments, the viscosities measured by RVA are 50-1000 cP, 50-850 cP, 50-700 cP, 50-500 cP, 50-400 cP, 50-300 cP, 50-200 cP, 100-1100 cP, 100-1000 cP, 100-850 cP, 100-700 cP, 100-500 cP, 100-400 cP. Viscosities ranged from 100-300 cP, 200-1100 cP, 200-1000 cP, 200-850 cP, 200-700 cP, 200-500 cP, 400-1100 cP, 400-1000 cP, 400-850 cP, 400-700 cP, 600-1100 cP, 600-850 cP, 700-1500 cP, or 700-1300 cP. Viscosities were measured by RVA at 160 rpm with stirring in a pH 6.5 phosphate buffer solution containing 1% sodium chloride and 5% solids. The initial temperature for analysis was 50°C; the temperature was linearly increased to 90°C over 3 minutes, then held at 95°C for 20 minutes, then linearly decreased to 50°C over 3 minutes, and then held at 50°C for 9 minutes before viscosity was measured. It is worth noting that when a gelatinization peak is observed at approximately 2–5 minutes, the measured final viscosity is higher than the gelatinization peak viscosity. When no gelatinization peak is observed, the viscosity remains flat or increases during the 95°C holding period.

[0052] As described above, the stable waxy starch based on corn, wheat, or cassava of the present invention is not pregelatinized.

[0053] In some embodiments, the corn, wheat, or cassava-based stabilized waxy starch of the present invention retains substantially intact granules upon cooking. As used herein, the particle size is determined as follows: a container containing the slurry is first suspended in a 95°C water bath and stirred for 6 minutes with a glass rod or metal spatula. The container is then covered, and the slurry is kept at 95°C for another 20 minutes. The slurry is then cooled to room temperature, thereby cooking the starch in a salt-buffered solution with a 5% solids content. After cooking, expanded but intact granules can be observed under a microscope. Those skilled in the art will understand that minor deviations in particle size are permissible. For example, in some embodiments of the corn, wheat, or cassava-based stabilized waxy starches further described herein, no more than 30% of the starch granules become incomplete after cooking (i.e., as described above regarding particle size). In some such embodiments, no more than 20% or even no more than 10% of the starch granules become incomplete after cooking (i.e., as described above regarding particle size). Those skilled in the art can determine whether starch granules remain intact by observing them under a microscope (e.g., by staining), which is a common practice in the art.

[0054] Some ideal embodiments of the stabilized waxy starches based on corn, wheat, or cassava described herein are substantially digestible. For example, in some embodiments of the stabilized waxy starches based on corn, wheat, or cassava further described herein, the amount of fiber is less than 10%, as determined by AOAC 2001.03. In some such embodiments, the amount of fiber is less than 5%, or even less than 2%.

[0055] As described above, the starch of the present invention is stable. As used herein, the term "stable starch" refers to starch exhibiting "processing tolerance." As used herein, the term "processing tolerance" refers to starch granules that swell in water during cooking but essentially retain their natural state throughout the processing. Processing-tolerant starches do not break down into incomplete portions or dissolve during processing. The degree of stability of stable starches may vary and is characterized by observed microscopic images and swelling volumes. The degree of stability can be assessed by cooking the starch in water (typically at 95°C for 30 minutes, with hand stirring for the first 6 minutes) and then observing the cooking process under a microscope. Unstable starches will have a small number of granules and incomplete portions because they readily dissolve in water during cooking. Stable starches will show swollen, intact granules under a microscope, with strongly stable starches showing small, dark granules and weakly stable starches showing large, light granules. Alternatively, the degree of stability can be assessed by measuring the sedimentation volume of the starch as described above.

[0056] The stable waxy starch based on corn, wheat, or cassava of the present invention can be prepared by a variety of methods. A variety of waxy starch raw materials can be used (e.g., natural starches such as waxy cassava starch or waxy corn starch, or any other waxy starch described herein). The waxy starch raw materials can be pretreated, for example, to reduce the amount of lipids and / or proteins present in the starch, which is a common practice in the art.

[0057] In some embodiments, the stable waxy starch based on corn, wheat, or cassava of the present invention is prepared using the method described in International Patent Application Publication No. WO 2013 / 173161, the entire contents of which are incorporated herein by reference. Therefore, the method for preparing the starch described herein may include:

[0058] (a) Heating non-pregelatinized granular waxy starch in an alcoholic medium at a temperature of at least 35°C in the presence of an alkali;

[0059] (b) Neutralize the base with acid;

[0060] (c) Separation of stable granular waxy starch from an alcoholic medium; and

[0061] (d) Remove alcohol solvent from stable waxy granular starch, for example by heating or using steam.

[0062] The alcohol medium typically comprises at least one alcohol, particularly C1-C4 monohydric alcohols such as methanol, ethanol, n-propanol, isopropanol, n-butanol, tert-butanol, etc. The alcohol medium may also contain one or more other substances, such as non-alcoholic organic solvents (particularly miscible with alcohols) and / or water. However, in one embodiment of the method, the alcohol medium does not contain any solvent other than alcohol and water (optionally). For example, aqueous alcohols can be advantageously used. The alcohol medium may comprise, for example, 30% to 100% by weight of alcohol (e.g., ethanol) and 0% to 70% by weight of water. In one embodiment, the alcohol medium comprises 80% to 96% by weight of alcohol (e.g., ethanol) and 4% to 20% by weight of water, the total amount of alcohol and water being equal to 100%. In another embodiment, the alcohol medium comprises 90% to 100% by weight of alcohol (e.g., ethanol) and 0% to 10% by weight of water, the total amount of alcohol and water being equal to 100%. In other embodiments, the alcohol medium contains no more than 10% by weight or no more than 15% by weight of water. The amount of alcohol medium relative to starch is not critical, but sufficient alcohol medium is typically required for ease of processing to obtain a stirable and / or pumpable slurry. For example, the weight ratio of starch to alcohol medium is approximately 1:2 to approximately 1:6.

[0063] In some methods, a certain amount of treatment agent (alkali and / or salt) is present when the waxy starch feedstock is heated in an alcoholic medium. However, it is advantageous that a large amount of treatment agent (relative to starch) is not required to achieve effective starch inhibition compared to previously known starch modification methods. This simplifies subsequent processing of stabilized waxy starches based on corn, wheat, or cassava and reduces potential production costs. Typically, at least 0.5% by weight of treatment agent (based on the dry weight of starch used) is used, although in other embodiments at least 1%, at least 2%, at least 3%, at least 4%, or at least 5% by weight of treatment agent are present. For economic reasons, the treatment agent typically does not exceed 10% by weight.

[0064] Typically, the mixture of starch, alcohol medium, and treatment agent is in the form of a slurry. In some embodiments, it may be necessary to adjust the pH of the slurry to a specific value. Due to the presence of alcohol, it is difficult to measure the pH of such a slurry. In embodiments where it is necessary to make the slurry alkaline by adding alkali, a suitable amount of alkali can be determined as if the slurry were a starch slurry in deionized water alone, and then increased proportionally to the actual amount while keeping the alkali-to-starch ratio constant.

[0065] For example, the slurry can be neutral (pH 6-8) or alkaline (pH greater than 8). In one embodiment, the pH of the slurry is at least 6. In another embodiment, the pH of the slurry is at least 7. In another embodiment, the pH of the slurry does not exceed 12. In other embodiments, the pH of the slurry is 6-10, 7.5-10.5, or 8-10. In other embodiments, the pH of the slurry is 5-8 or 6-7.

[0066] Alcohol treatment of starch can be achieved by first placing the starch in an alcohol medium and then adding a treatment agent (e.g., a alkali and / or a salt). Alternatively, the treatment agent can be mixed with the alcohol medium first and then contacted with the starch. The treatment agent can be formed in situ, for example by adding a alkali and an acid separately, which react to form a salt that can be used as the treatment agent.

[0067] The alkalis suitable for this process include, but are not limited to, alkali metal and alkaline earth metal hydroxides, such as potassium hydroxide, calcium hydroxide and sodium hydroxide.

[0068] Salts suitable for these methods include water-soluble substances that ionize in aqueous solutions to produce essentially neutral solutions (i.e., solutions with a pH of 6 to 8). Salts containing alkali metals are particularly useful, as are organic acid salts (such as sodium or potassium salts) such as itaconic acid, malonic acid, lactic acid, tartaric acid, citric acid, oxalic acid, fumaric acid, aconitic acid, succinic acid, oxaloylsuccinic acid, glutaric acid, ketoglutaric acid, malic acid, fatty acids, and combinations thereof.

[0069] A mixture of different processing agents can be used. For example, starch can be heated in an alcoholic medium in the presence of at least one alkali and at least one salt.

[0070] The starch, alcohol medium, and treatment agent are heated for a period of time, at a temperature sufficient to effectively suppress the starch to the desired level. Generally, the temperature needs to be above room temperature (i.e., 35°C or higher). Extremely high temperatures should be avoided. Heating temperatures can range from, for example, 35°C to 200°C. Typically, temperatures of 100°C to 190°C, 120°C to 180°C, 130°C to 160°C, or 140°C to 150°C are sufficient. Heating time is generally at least 5 minutes but no more than 20 hours, typically 40 minutes to 2 hours. Generally, higher heating temperatures will achieve the desired starch stability level more quickly.

[0071] Specific processing times, temperatures, and component ratios of the starch, alcohol medium, and treatment agent mixture are typically chosen to prevent the starch from gelling to a large extent. In other words, the starch remains non-pregelatinized as described above.

[0072] When the temperature used for the heating step exceeds the boiling point of one or more components of the alcohol medium, it is advantageous to perform the heating in a pressurized vessel or other equipment. The treatment can be carried out within a defined area to keep the alcohol medium in a liquid state. Additional positive pressure may be applied, but is generally not required. Starch can be slurried in the alcohol medium with a treatment agent under high temperature and pressure conditions and treated for a sufficient time to alter the viscosity properties of the starch. This treatment can be carried out batch-wise in a stirred tank reactor or continuously in a tubular reactor, while other suitable treatment techniques will be apparent to those skilled in the art. In another embodiment, the starch may be in the form of a bed in a tubular reactor through which a mixture of the alcohol medium and the treatment agent passes (optionally, continuously), wherein the bed is maintained at a desired temperature to achieve inhibition of starch.

[0073] In embodiments using alkali as a treatment agent, once the heating step is complete, the mixture of starch, alcohol medium, and alkali can be combined with one or more acids to neutralize the alkali. Acids suitable for this neutralization step include, but are not limited to, carboxylic acids such as itaconic acid, malonic acid, lactic acid, tartaric acid, oxalic acid, fumaric acid, aconitic acid, succinic acid, oxaloylsuccinic acid, glutaric acid, ketoglutaric acid, malic acid, citric acid, fatty acids and combinations thereof, as well as other types of acids such as uric acid. If the stabilized starch is used as a food ingredient, the acid should generally be an acid conforming to applicable regulations. Sufficient acid is typically added to lower the pH of the mixture to approximately neutral to slightly acidic, for example, a pH of approximately 5 to approximately 7 or approximately 6 to approximately 6.5.

[0074] The acid neutralization step can be carried out at any suitable temperature. In one embodiment, the slurry of starch, alkali, and alcohol medium is cooled from the heating temperature to approximately room temperature (e.g., approximately 15°C to approximately 30°C) before being combined with the acid used for neutralization. The neutralized mixture can be further processed as described below to separate the stable starch from the alcohol medium. However, in another embodiment, the starch slurry is further heated after alkali neutralization. It has been found that further heating can alter the rheological properties of the obtained stable starch compared to the viscosity properties of starch prepared by a similar method without heating after alkali neutralization.

[0075] Generally, the further heating step is advantageously carried out at temperatures above room temperature (i.e., 35°C or higher). At the same time, extremely high temperatures should be avoided. Heating temperatures can be, for example, from 35°C to 200°C. Typically, temperatures of 100°C to 190°C, 120°C to 180°C, 130°C to 160°C, or 140°C to 150°C are sufficient. Heating time is generally at least 5 minutes but not more than 20 hours, typically 40 minutes to 2 hours.

[0076] A mixture of starch and an alcohol medium can be processed to separate starch from the alcohol medium. Conventional methods for recovering particulate solids from liquids, such as filtration, decantation, sedimentation, or centrifugation, are suitable for this purpose. The separated starch can optionally be washed with another alcohol medium and / or alcohol and / or water to remove any excess soluble impurities. In one embodiment, neutralization of residual alkali is accomplished by washing the recovered starch with an acidified liquid medium. According to the invention, the starch separated by drying can produce stable, non-pregelated granular starch. For example, drying can be carried out in suitable equipment such as an oven or fluidized bed reactor or dryer or mixer at moderately high temperatures (e.g., 30°C to 60°C). Vacuum and / or gas purging (e.g., nitrogen purging) can be applied to facilitate the removal of volatile substances (e.g., water, alcohol) from the starch. The resulting dried, stable, non-pregelated granular starch can be crushed, ground, milled, screened, sieved, or processed by any other similar technique to obtain the desired particle size. In one embodiment, the stable starch is in the form of free-flowing granular material.

[0077] However, in one embodiment, the starch is desolventized at significantly higher temperatures (e.g., greater than 80°C, 100°C, or 120°C). However, excessively high temperatures should be avoided as they may cause starch degradation or discoloration. This step not only reduces the amount of residual solvent (alcohol) in the product but also provides other unintended benefits, namely improved starch stability. The desolventizing temperature can be, for example, from about 100°C to about 200°C. Typically, the temperature is 120°C to 180°C or 150°C to 170°C. Desolventizing can be performed with or without steam. Steam treatment has been found advantageous as it helps minimize the degree of starch discoloration, which could otherwise occur at such high temperatures. In one embodiment, steam is passed through a bed or block of stable waxy starch based on corn, wheat, or cassava. The starch desolventizing method of U.S. Patent No. 3,578,498, the entire contents of which are incorporated herein by reference for all purposes. After steam treatment, stabilized waxy starch based on corn, wheat, or cassava can be dried to reduce residual moisture content (e.g., by heating in an oven at about 30°C to about 70°C or in a fluidized bed reactor).

[0078] In one embodiment, the treated starch recovered from the alcohol medium initially reaches a total volatile content of no more than about 35% by weight or no more than about 15% by weight. This can be achieved, for example, by first air-drying or oven-drying the recovered starch at a moderate temperature (e.g., 20°C to 70°C) to the desired initial volatile content. Fresh steam is then passed through the dried starch, and the system is maintained at a temperature above the steam condensation point. A fluidized bed apparatus can be used to perform this steam desolvation step.

[0079] Generally, it is desirable to perform desolventizing under conditions that allow the residual alcohol content in stable waxy starches based on corn, wheat, or cassava to be less than 1% by weight, 0.5% by weight, or 0.1% by weight, respectively.

[0080] After desolventization, the stabilized waxy starch based on corn, wheat, or cassava can be washed with water and then dried to further improve color and / or flavor and / or reduce moisture content.

[0081] Of course, those skilled in the art can use other methods to obtain the starch described herein. Waxy starch raw materials can be subjected to, for example, pH adjustment and heating. The pH can be adjusted by contacting the starch with a pH adjuster; examples of pH adjusters include formic acid, propionic acid, butyric acid, oxalic acid, lactic acid, malic acid, citric acid, fumaric acid, succinic acid, glutaric acid, malonic acid, tartaric acid, itaconic acid, aconitic acid, oxaloylsuccinic acid, ketoglutaric acid, fatty acids, and carbonic acid, and their salts (e.g., potassium and / or sodium salts, which can be produced in situ by neutralization of the acid). The pH adjuster can be contacted with the starch raw material in any convenient manner, for example, as a slurry in a liquid, such as water, an alcohol (e.g., including ethanol or isopropanol as described above), including aqueous alcohols such as aqueous ethanol, or another solvent; in a dry form; in a wet form, such as as a mist in a solvent (e.g., water, aqueous ethanol, or another solvent); or in the form of a moist starch dough, for example using water, aqueous ethanol, or another solvent. When an alkali metal salt of an acid is required, the alkali metal salt can be formed in situ, for example by adding an acid and an alkali metal hydroxide or carbonate, respectively.

[0082] pH adjustment can be performed to produce a variety of pH values. For example, in some embodiments, as described in WO 2013 / 173161, pH adjustment can be performed to produce pH values ​​in the range of 7-10. In other alternative embodiments, pH adjustment can be performed to produce pH values ​​in the range of 3-7, such as 3-6, 3-5, 3-4, 4-7, 4-6, 4.5-7, 4.5-6, 5-7, 5-6, approximately 3, approximately 3.5, approximately 4, approximately 4.5, approximately 5, approximately 5.5, approximately 6, approximately 6.5, or approximately 7. When pH adjustment is performed in a slurry, the pH value of the slurry is the relevant pH value. When pH adjustment is performed in a substantially non-liquid form (e.g., dough or moist solid), the pH value of the solid material (38%) in water is the relevant pH value. Based on dry solids, the amount of pH adjuster relative to starch can vary from, for example, 0.05 wt% to 30 wt%, such as 0.05-20 wt%, 0.05-10 wt%, 0.05-5 wt%, 0.05-2 wt%, 0.05-1 wt%, 0.05-0.5 wt%, 0.2-30 wt%, 0.2-20 wt%, 0.2-10 wt%, 0.2-5 wt%, 0.2-2 wt%, 0.2-1 wt%, 1-30 wt%, 1-20 wt%, 1-10 wt%, 1-5 wt%, 5-30 wt%, or 5-20 wt%. Ideally, the pH adjuster is thoroughly mixed with the starch raw material. This will require different process conditions depending on how the pH is adjusted. If pH adjustment is performed in a slurry, simply stirring the slurry for a few minutes is sufficient. If pH adjustment is performed in a drier form (e.g., moist solids or dough), a more thorough contact process may be required. For example, if a pH adjuster solution is sprayed onto dry starch raw materials, it may require mixing for about 30 minutes, followed by storage for at least several hours. The pH adjuster should be evenly distributed throughout the starch, i.e., evenly distributed at the granular level, to achieve a uniform inhibitory effect.

[0083] After contacting the starch with a pH adjuster, the starch can be heated (while still in contact with the pH adjuster). The starch can be heated in several ways. For example, it can be heated in an alcohol or non-aqueous solvent slurry (e.g., under pressure if the solvent's boiling point is not sufficiently higher than the heating temperature); in the form of a dough of starch, water, and non-aqueous solvent to suppress particle swelling (e.g., as disclosed in WO 2013 / 173161); or in a dry state (the solvent can be removed using conventional techniques such as filtration, centrifugation, and / or thermal drying, e.g., as described above with respect to WO 2013 / 173161). Before further heating, the starch can be dried, for example, to a moisture content of less than 5%. Drying can be carried out at relatively low temperatures (e.g., 40-80°C, 40-60°C, or about 50°C). Vacuum drying can also be used. The starch can be dried during heating (see below); thus eliminating the need for a separate drying step.

[0084] Dry starch can be heated in a temperature range of 100-200°C. For example, in some methods, the heating temperature is 120-160°C. In various other methods, the heating temperature is 120-180°C, 120-160°C, 120-140°C, 140-200°C, 140-180°C, 140-160°C, 160-200°C, 160-180°C, or 180-200°C. Starch can be heated multiple times. The heating time for starch can range from, for example, 20 seconds to 20 hours. Typical heating times are between 10 minutes and 2 hours. Stronger inhibition can be achieved through longer heating times and / or higher heat treatment temperatures. Ideally, the material is heated uniformly. Starch can be heated under pressure to maintain the desired moisture content, or it can be heated in a monolithic flow chamber or similar device.

[0085] Some of the methods described herein can be used, for example, without using alcohols for contacting pH adjusters in a liquid medium. In some particularly desirable methods, water is used as the pH adjusting medium. Thus, in some desired embodiments, the stable waxy starch based on corn, wheat, or cassava contains less than 500 ppm of an alcohol solvent, such as less than 500 ppm of ethanol. For example, in various embodiments, the stable waxy starch based on corn, wheat, or cassava contains less than 100 ppm, less than 50 ppm, less than 10 ppm, less than 5 ppm, or less than 1 ppm of an alcohol solvent, such as less than 100 ppm, less than 50 ppm, less than 10 ppm, less than 5 ppm, or less than 1 ppm of ethanol.

[0086] Heated starch can be used directly after cooling, or it can be further processed according to conventional methods in the art. For example, washing starch results in a whiter color and better taste. If a non-aqueous solvent is used, it is necessary to remove the solvent as much as possible. However, if a relatively low level of pH adjuster is used, the final product can achieve reasonable pH and ash targets without further washing.

[0087] As those skilled in the art will understand, starch feedstocks can be purified, for example, by conventional methods to reduce undesirable tastes, odors, or colors, such as those inherent to starch or present in other ways. For example, methods such as washing (e.g., alkaline washing), stripping, ion exchange processes, dialysis, filtration, bleaching (e.g., by chlorite), enzymatic modification (e.g., to remove proteins), and / or centrifugation can be used to reduce impurities. Those skilled in the art will understand that the purification operations can be performed at multiple suitable points in the process.

[0088] Another aspect of the invention is a pregelatinized starch prepared by a method comprising gelation and drying of a stable waxy starch based on corn, wheat, or cassava as described herein (i.e., to provide a material based on at least 95% by weight, or even at least 99% by weight, of pregelatinized starch in the absence of substantially any other food ingredients). Conventional pregelation methods will be used by those skilled in the art.

[0089] The starch described herein can be used as a thickener or viscous agent, for example, to increase the viscosity of fluid or semi-solid compositions. One problem with conventional starches is that they dehydrate due to intermolecular bonding during storage (e.g., long-term storage), low-temperature storage, or freeze-thaw cycles, and irreversibly lose moisture through a process called dehydration shrinkage. This significantly reduces the texture and transparency of food. Advantageously, when food containing the starch of this invention is cooked and cooled to the desired storage temperature, it can maintain its texture properties for an extended period throughout its storage life and resist temperature fluctuations (e.g., freeze-thaw cycles) during storage. Therefore, food containing the starch described herein can substantially achieve freeze-thaw stability, refrigeration stability, and / or storage stability. In some embodiments further described herein, the stabilized waxy starch has one or more of the following properties: (1) a particle size of 4 or smaller after three freeze-thaw cycles; (2) a dehydration shrinkage of 5 or smaller, even 3 or smaller, after three freeze-thaw cycles; and (3) a hardness change of no more than 2 after three freeze-thaw cycles. The measurements of all these properties are described in the following examples.

[0090] Therefore, another aspect of the present invention is a food production method. This method includes cooking the starch described herein with water; and combining the cooked starch with one or more other food ingredients. For example, the starch described herein may be combined with one or more other food ingredients including water, and the composition of the starch and food ingredients may be cooked. In certain embodiments, the method includes pasteurization, dry distillation, autoclaving or batch cooking, or ultra-high temperature processing. Optionally, the starch may be cooked alone and then combined with one or more food ingredients.

[0091] Food products can include, for example, tomato products, gravy, sauces (such as white sauce or cheese sauce), soups, puddings, salad dressings (such as pourable or scoopable), yogurt, sour cream, custard, cheese products, fruit fillings or toppings, cream fillings or toppings, syrups (such as diluted syrups), beverages (such as dairy beverages), liquids, condiments, candies, pasta, frozen foods, or cereals. A variety of cooking methods can be used, such as pasteurization, dry distillation, pot cooking, batch cooking, and UHT processing.

[0092] The starch described herein can also be used to modify the properties of solid foods (e.g., baked goods), for example, as an antiseptic to make the product softer and retain its fresh texture after storage. Therefore, in other embodiments, the food is a baked good, such as bread, pastries, pie crusts, donuts, cakes, cookies, biscuits, crackers, or muffins. In such embodiments, cooking may include baking. In some embodiments, the use of the starch described herein in baked goods (i.e., in dough or batter) helps prevent the food from spoiling. In other embodiments, the starch may be included in fillings, for example, within baked goods.

[0093] The starch of this invention can be advantageously used to produce a variety of other food products. For example, the starch of this invention is suitable for foods including heat-processed foods, acidic foods, dry mixtures, frozen foods, refrigerated foods, extruded foods, oven-prepared foods, oven-cooked foods, microwave foods, full-fat or low-fat foods, and foods with low water activity. The starch of this invention is particularly suitable for foods requiring heat treatment, such as pasteurization, dry distillation, high-temperature short-time treatment, or ultra-high-temperature treatment. The starch of this invention is particularly suitable for food applications requiring stability at all processing temperatures (including cooling, freezing, and heating).

[0094] Based on the formulation of processed foods, the amount and type of starch of this invention can be easily selected according to the required thickness, gel viscosity, and texture of the final food. Typically, the amount of starch used is 0.1-35% of the food weight, for example, 0.5-6.0%.

[0095] The starch of this invention can be used to improve the following foods: high-acid foods (pH < 3.7), such as fruit pie fillings, baby food, etc.; acidic foods (pH 3.7-4.5), such as tomato products; low-acid foods (pH > 4.5), such as gravy, sauces, and soups; oven-cooked foods, such as sauces, gravy, and puddings; convenience foods, such as puddings; pourable and scoopable salad dressings; refrigerated foods, such as dairy products or imitation dairy products (e.g., yogurt, sour cream, and cheese); frozen foods, such as frozen desserts and fast food; microwaveable foods, such as frozen fast food; liquid products, such as weight-loss products and hospital meals; dry mixtures for preparing baked goods, gravy, sauces, puddings, baby food, hot cereals, etc.; and dry mixtures for use as a base before batter cooking and frying.

[0096] In other embodiments, the food is candy.

[0097] The starch described herein can be used in a variety of other foods. For example, in some embodiments of the starch and method of the present invention, the starch is used in foods selected from baked goods, breakfast cereals, anhydrous coatings (e.g., ice cream composite coatings, chocolate), dairy products, confectionery, jams and jellies, beverages, fillings, extruded sheet snacks, gel snacks, snack bars, cheese and cheese sauces, edible water-soluble films, soups, syrups, sauces, seasonings, creamer, sugar coatings, icing, slurries, tortillas, meat and fish, dried fruit, infant foods, and batters and breads. The starch described herein can also be used in various medical foods. The starch described herein can also be used in pet food.

[0098] The starch of the present invention can also be used in a variety of non-food applications that traditionally use chemically modified (crosslinked) stabilized starch, including, for example, cosmetics and personal care products, paper, packaging materials, pharmaceutical preparations, adhesives, etc.

[0099] Ideally, the starch of the present invention can provide excellent properties, such as freeze-thaw stability and good digestibility. The inventors have determined that, unlike many highly modified starches, the starch described herein can be sufficiently inhibited to achieve desired properties, such as ideal viscosity characteristics and ideal freeze-thaw tolerance, without becoming difficult to digest or causing indigestion even under harsh storage conditions.

[0100] For example, in certain desired embodiments further described herein, the starch of the present invention has one or more of the following properties (e.g., two or more, or all three):

[0101] (a) Ideal viscosity, such as viscosity in the range of 50-1500 cP as measured by RVA; in some such embodiments, the viscosity measured by RVA is 50-1000 cP, 50-850 cP, 50-700 cP, 50-500 cP, 50-400 cP, 50-300 cP, 50-200 cP, 100-1100 cP, 100-1000 cP, 100-850 cP, 100-700 cP, 100 -500cP, 100-400cP, 100-300cP, 200-1100cP, 200-1000cP, 200-850cP, 200-700cP, 200-500cP, 400-1100cP, 400-1000cP, 400-850cP, 400-700cP, 600-1100cP, 600-850cP, 700-1500cP, or 700-1300cP;

[0102] (b) Ideal freeze-thaw properties, such as one or more of the following: (1) particle size of 4 or smaller after three freeze-thaw cycles; (2) dehydration shrinkage of 5 or smaller, or even 3 or smaller, after three freeze-thaw cycles; and (3) hardness change of no more than 2 after three freeze-thaw cycles; and

[0103] (c) Good digestive tolerance.

[0104] Another aspect of the invention is a dry mixture comprising the starch described herein, and one or more food ingredients. When the dry mixture is cooked (i.e., in water), a longer time is required for gelation, thus allowing for a longer period of time to hold and transport (e.g., by pumping) the cooked product and to fill containers before gelation. The dry mixture can be, for example, a dry mixture for baked goods, such as bread, pastries, pie crusts, donuts, cakes, cookies, biscuits, crackers, or muffins.

[0105] The following is a further description of the example.

[0106] Example 1 - Viscosity and sedimentation volume of stabilized waxy starch

[0107] The pH of the waxy starch raw material is adjusted using one of the following pH adjusters: formic acid, propionic acid, butyric acid, oxalic acid, lactic acid, malic acid, citric acid, fumaric acid, succinic acid, glutaric acid, malonic acid, tartaric acid, itaconic acid, aconitic acid, oxaloylsuccinic acid, ketoglutaric acid, and carbonic acid, and their salts (e.g., potassium and / or sodium salts, which can be generated in situ by neutralization of the acid). The pH adjuster is contacted with the starch raw material in a slurry in a liquid (e.g., water) for several minutes while stirring. The pH value can be adjusted in the range of 3.5 to 7.0. Based on the dry solids basis weight of the starch, the amount of pH adjuster relative to the starch can be, for example, 0.01-30% by weight. After contacting the starch with the pH adjuster, the starch (while still in contact with the pH adjuster) is dried to a moisture content of less than 1% before further heating, and the dried starch is heated at a temperature of 100-200°C for a period of time, for example, 20 seconds to 20 hours.

[0108] According to information provided by the supplier, both natural waxy corn starch and natural waxy tapioca starch have amylopectin content exceeding 90%. Sedimentation volume and RVA viscosity data for natural and stabilized waxy starches are shown in Table 1 below. Samples 1-4 were prepared using natural waxy tapioca starch as raw material, while samples 5-7 were prepared using natural waxy corn starch as raw material. The most common sedimentation volume range in food applications is generally considered to be 20-35 mL / g.

[0109] Table 1. Final viscosity and sedimentation volume (SV) of the experimental samples using RVA

[0110]

[0111] Viscosities were measured by RVA in a salt buffer solution with a stirring speed of 160 rpm and a solids content of 5%. The initial temperature for analysis was 50 °C; the temperature was linearly increased to 90 °C over 3 minutes, then held at 95 °C for 20 minutes, then linearly decreased to 50 °C over 3 minutes, and then held at 50 °C for 9 minutes. Viscosities were measured throughout the entire heating and cooling cycle, and the viscosity at the end of the cycle was taken as the RVA viscosity. Compared with natural waxy starch, samples 1-7 did not have a large peak at the start of the RVA curve and maintained a stable viscosity at high temperatures.

[0112] Example 2

[0113] Branch length distribution analysis - valley method

[0114] As described above, the branch chain length distribution of the natural or stable waxy starches described herein was determined using the gluten-graft method. The results show... Figure 1 and 2The present invention indicates that the DP13-24 amylopectin fraction of the stabilized waxy cassava starch does not exceed 48.0%, while the DP13-24 amylopectin fraction of other stabilized starches exceeds 48.5%; and the ratio (DP13-24-DP6-12) / (DP13-24+DP6-12) of the stabilized waxy cassava starch of the present invention is less than 25.0%, while the ratio (DP13-24-DP6-12) / (DP13-24+DP6-12) of other stabilized starches is greater than 25.5%. Detailed data are provided in the table below, which shows parallel determinations for each material.

[0115] Table 2 Distribution of cereal branch chain lengths of natural starch and stabilized starch

[0116]

[0117] Example 3 - Freeze-thaw stability of stable waxy starch

[0118] A series of experiments were conducted to investigate various texture properties related to the freeze-thaw stability of the starch of the present invention. To assess texture properties, various starches of the present invention and commercially available stable waxy starches based on corn, wheat, or cassava were cooked in deionized water at a 5% solids content. Specifically, the container containing the slurry (i.e., glass jar) was suspended in a 95°C water bath and stirred for 8 minutes with a glass rod or metal spatula. The container was then covered, and the slurry was kept at 95°C for another 20 minutes. The container was removed from the water bath and allowed to cool on a workbench. The resulting slurry was restored to its initial weight by adding water (to replace the evaporated water) and thoroughly mixed. The glass jars used for the first, second, and third freeze-thaw cycles were placed in a freezer (-18°C), ensuring the jars did not touch each other and were not in containers or boxes or otherwise insulated. The jars were allowed to stand overnight (16-18 hours). The samples were removed from the freezer and placed on a laboratory bench, ensuring the jars did not touch each other. The jars were allowed to rise to room temperature and held for at least 6 hours. This completed the first freeze-thaw cycle. Samples used for the second and third freezing cycles were returned to the freezer to repeat the freezing and thawing steps. The samples were evaluated by the team members on the day of cooking and after each freeze-thaw cycle. The starches studied were Sample 6; Control Starch A; and Sample 2 described in Table 2. Control Starch A was a modified waxy corn starch esterified from acetic anhydride and adipic anhydride, wherein acetyl groups comprised 1.2–1.5% of the starch weight and adipic ester groups comprised 0.1% of the starch weight.

[0119] As described below, the panel members evaluated opacity, stiffness, dehydration shrinkage, and particle size. Each attribute was scored on a 15-point scale. Each group had a different scoring reference.

[0120] Hardness was determined by comparing it with commercially available products:

[0121] Hardness 3 – Mild Creamy Almond and Verbena Shower Gel

[0122] • Hardness 7 – Shea butter moisturizing coconut and hibiscus curling gel soufflé / agave nectar and flaxseed oil

[0123] • Hardness 11 – Garnier Power Surfer Clay

[0124] To determine hardness, the test starch and reference product were poked 2-3 times with the back of a spoon; the force exerted by the test starch on the spoon relative to the reference product was estimated. A higher number indicates greater hardness.

[0125] Through with Figure 3 The opacity is determined by comparing photos of the starch to a black background. The starch is tested in a 250mL beaker, about 1 inch in front of the black background. The higher the number, the higher the opacity.

[0126] The dehydration shrinkage rate is determined by gently pressing the test sample (approximately halfway down) at a 45-degree angle to the sample surface, then observing from the side how much water is squeezed out within 3 seconds. The level of dehydration shrinkage is compared with... Figure 4 The images were compared to determine this.

[0127] By observing the top surface of the test starch and comparing it with... Figure 5 The images are compared to determine the grain size (i.e., surface grain size).

[0128] Figure 6-8 Bar graphs showing the average values ​​of three test attributes for each product during freeze-thaw cycles are provided (Sample 6; Control Starch A; and Sample 2, respectively). Unlike Sample 6 and Control Starch A, the stable waxy cassava starch of the present invention (Sample 2) exhibits good freeze-thaw stability.

[0129] Figure 9 This indicates a correlation between the above ratio and starch freeze-thaw stability. The change in hardness after three freeze-thaw cycles is a measure of starch stability, calculated by dividing the difference between the hardness after three freeze-thaw cycles and the hardness of the fresh sample by the total number. As mentioned above, the total number is 15. When the ratio does not exceed 25.5%, the change in hardness is negligible; when the ratio is above 25.5%, the change in hardness is significant, indicating poor freeze-thaw stability.

[0130] Example 4

[0131] Branch length distribution analysis - baseline reduction method

[0132] As described above, the amylopectin length distribution of the stable waxy cassava starch described herein and commercially available stable starches was determined using the baseline reduction method (results are shown in Table 3); the data are the average of two parallel determinations. The results shown in the table below indicate that the DP13-24 amylopectin fraction of the stable waxy cassava starch of the present invention does not exceed 54.5%, while the DP13-24 amylopectin fraction of other commercially available stable starches exceeds 54.5%; the DP6-12 amylopectin fraction of the stable waxy cassava starch of the present invention is at least 30.5%, while the DP6-12 amylopectin fraction of other commercially available stable starches is less than 30.5%; and the ratio (DP13-24-DP6-12) / (DP13-24+DP6-12) of the stable waxy cassava starch of the present invention is less than 28.0%, while the ratio (DP13-24-DP6-12) / (DP13-24+DP6-12) of other stable starches is greater than 28.0%.

[0133] Table 3. Baseline branch length distribution of stable starch

[0134]

Claims

1. A stable waxy tapioca starch, Its amylopectin content is 90-100%; and The sedimentation volume is 18-35 mL / g; The amylopectin fraction of the stabilized waxy cassava starch has no more than 54.5% medium-length branches with a chain length of 13-24, as determined by the baseline reduction method, and / or The amylopectin portion of the stabilized waxy cassava starch has at least 30.5% short branches with chain lengths of 6-12, as determined by the baseline reduction method. The ratio (DP13-24-DP6-12) / (DP13-24+DP6-12) does not exceed 28.0%, where DP13-24 is the amount of medium-length branches with a chain length of 13-24 in the amylopectin fraction of the stabilized waxy cassava starch, determined by baseline reduction method; and DP6-12 is the amount of short branches with a chain length of 6-12 in the amylopectin fraction of the stabilized waxy cassava starch, determined by baseline reduction method. The stabilized waxy cassava starch is prepared by adjusting the pH of an aqueous slurry of cassava starch raw material to a range of 3.5-7.0, followed by drying and heating the pH-adjusted starch, and the stabilized waxy cassava starch is not pre-gelled. Stable waxy cassava starch is not hydroxypropylated, not acetylated, not carboxymethylated, not hydroxyethylated, not phosphorylated, not succinylated, is not cationic or zwitterionic, is not crosslinked with phosphates, not crosslinked with adipates, not crosslinked with epichlorohydrin, and is not crosslinked with acrolein.

2. The stabilized waxy cassava starch according to claim 1, wherein the amylopectin portion of the stabilized waxy cassava starch has no more than 54.0% medium-length branches with a chain length of 13-24.

3. The stabilized waxy cassava starch according to claim 1, wherein the amylopectin portion of the stabilized waxy cassava starch has 52.0%-54.5% or 52.5%-54.5% of medium-length branches with a chain length of 13-24.

4. The stabilized waxy cassava starch according to any one of claims 1-3, wherein the amylopectin portion of the stabilized waxy cassava starch has at least 31.0% short branches with a chain length of 6-12.

5. The stabilized waxy cassava starch according to any one of claims 1-3, wherein the amylopectin portion of the stabilized waxy cassava starch has 30.5%-33.5%, 30.5%-33.0%, 30.5%-32.5%, 31.0%-33.5%, 31.0%-33.0%, or 31.0%-32.5% short branches with a chain length of 6-12.

6. The stable waxy cassava starch according to any one of claims 1-3, wherein the ratio (DP13-24-DP6-12) / (DP13-24+DP6-12) does not exceed 27.5%.

7. The stable waxy cassava starch according to any one of claims 1-3, wherein the ratio (DP13-24-DP6-12) / (DP13-24+DP6-12) does not exceed 27.0%.

8. The stabilized waxy cassava starch according to any one of claims 1-3, wherein the ratio (DP13-24-DP6-12) / (DP13-24+DP6-12) is 24.5%-28.0%, 24.5%-27.5%, 24.5%-27.0%, 25.0%-28.0%, 25.0%-27.5%, 25.0%-27.0%, 25.5%-28.0%, 25.5%-27.5%, or 25.5%-27.0%.

9. The stabilized waxy cassava starch according to any one of claims 1-3, wherein the amount of medium-length branches with a chain length of 13-24 in the amylopectin portion of the stabilized waxy cassava starch is at least 2 percentage points greater than the amount of medium-length branches with a chain length of 13-24 in the amylopectin portion of natural waxy rice starch, and the amount of medium-length branches with a chain length of 13-24 in the amylopectin portion of the stabilized waxy cassava starch is at least 2 percentage points lower than the amount of medium-length branches with a chain length of 13-24 in the amylopectin portion of natural waxy corn starch.

10. The stable waxy cassava starch according to any one of claims 1-3, wherein the amylopectin content is at least 99.9%.

11. The stable waxy cassava starch according to any one of claims 1-3, wherein the sedimentation volume is 18-30 mL / g, 18-25 mL / g, 20-35 mL / g, 20-30 mL / g, 20-25 mL / g, 25-35 mL / g, 25-30 mL / g, or 30-35 mL / g.

12. The stable waxy cassava starch according to any one of claims 1-3, wherein the color is relatively light, i.e., the yellow index does not exceed 10.

13. The stable waxy cassava starch according to any one of claims 1-3, wherein the stable waxy cassava starch has not been bleached or oxidized by peroxides or hypochlorites.

14. A food product comprising cooked food containing stable waxy tapioca starch according to any one of claims 1-13.

15. The food product according to claim 14, wherein the food product is based on tomato products.

16. The food product of claim 14, wherein the food product is gravy.

17. The food product according to claim 14, wherein the food product is a sauce.

18. The food product according to claim 14, wherein the food product is a soup.

19. The food product according to claim 14, wherein the food product is a seasoning.

20. The food product according to claim 14, wherein the food product is pudding.

21. The food product according to claim 14, wherein the food product is yogurt.

22. The food product according to claim 14, wherein the food product is jam.

23. The food product according to claim 14, wherein the food product is jelly.

24. The food product of claim 14, wherein the food product is a gel dessert.

25. The food product according to claim 14, wherein the food product is a snack bar.

26. The food product according to claim 14, wherein the food product is icing.

27. The food product according to claim 14, wherein the food product is a liquid slurry.

28. The food product according to claim 14, wherein the food product is a sugar coating.

29. The food product according to claim 14, wherein the food product is corn tortilla.

30. The food product according to claim 14, wherein the food product is infant or toddler food.

31. The food product according to claim 14, wherein the food product is a batter.

32. The food product according to claim 14, wherein the food product is bread.

33. The food product according to claim 14, wherein the food product is creamer.

34. The food product according to claim 14, wherein the food product is sour cream.

35. The food product according to claim 14, wherein the food product is a butter jelly.

36. The food product according to claim 14, wherein the food product is a cheese product.

37. The food product according to claim 14, wherein the food product is a fruit filling.

38. The food product according to claim 14, wherein the food product is a cream filling.

39. The food product according to claim 14, wherein the food product is a topping.

40. The food product of claim 14, wherein the food product is a syrup.

41. The food product according to claim 14, wherein the food product is a beverage.

42. The food product according to claim 14, wherein the food product is confectionery.

43. The food product according to claim 14, wherein the food product is pasta.

44. The food product according to claim 14, wherein the food product is a frozen food.

45. The food product according to claim 14, wherein the food product is a cereal product.

46. ​​The food product according to claim 14, wherein the food product is a baked food.

47. A food product comprising stabilized waxy tapioca starch, said stabilized waxy tapioca starch having... The amylopectin content is 90-100%; and The sedimentation volume is 18-35 mL / g; The stabilized waxy cassava starch wherein the amylopectin fraction has no more than 48.5% medium-length branches, with a chain length of 13-24, as determined by the gluten-gluten method; and At least 28.0% of the chains are short branches with a length of 6-12, measured by the valley-valley method; and in, The ratio (DP13-24-DP6-12) / (DP13-24+DP6-12) does not exceed 25.5%, where DP13-24 is the amount of medium-length branches with a chain length of 13-24 in the amylopectin fraction of the stabilized waxy cassava starch, and DP6-12 is the amount of short branches with a chain length of 6-12 in the amylopectin fraction of the stabilized waxy cassava starch, which is determined by the gluten-gluten method; and The stabilized waxy cassava starch is prepared by adjusting the pH of an aqueous slurry of cassava starch raw material to a range of 3.5-7.0, followed by drying and heating, and the stabilized waxy cassava starch is not pre-gelled. Stable waxy cassava starch is unhydroxypropylated, unacetylated, uncarboxymethylated, unhydroxyethylated, unphosphorylated, unsuccinylated, not cationic or zwitterionic, not crosslinked with phosphates, not crosslinked with adipates, not crosslinked with epichlorohydrin, and not crosslinked with acrolein; and Among them, food products are soups, sauces, or seasonings.

48. The food product according to claim 47, wherein, The stabilized waxy cassava starch has an amylopectin content of at least 99%.

49. The food product according to claim 47 or 48, wherein, The DP13-24 value of the amylopectin fraction of the stabilized waxy cassava starch is at least 3 percentage points higher than that of natural waxy rice starch; however, the DP13-24 value is at least 3 percentage points lower than that of natural waxy corn starch.

50. The food product according to claim 47 or 48, wherein, Stable waxy cassava starch has not been bleached or oxidized by peroxides or hypochlorites.

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