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StarchRelated Patent Categories: Food Or Edible Material: Processes, Compositions, And Products, Products Per Se, Or Processes Of Preparing Or Treating Compositions Involving Chemical Reaction By Addition, Combining Diverse Food Material, Or Permanent Additive, Carbohydrate Containing, ConfectionStarch description/claimsThe Patent Description & Claims data below is from USPTO Patent Application 20060216402, Starch. Brief Patent Description - Full Patent Description - Patent Application Claims
[0001] This application is a divisional of allowed U.S. patent application Ser. No. 10/272,291, filed Oct. 17, 2002, which is based on, and claims the benefit of, U.S. Provisional Application No. 60/329,525, filed Oct. 17, 2002, the entire contents of which are incorporated herein by reference [0002] The present invention relates to a starch defined herein as elastic starch. The presently disclosed starch has been made possible by engineering the waxy locus of starch producing plants, or the gene product of the waxy locus (i.e., the GBSS protein), which synthesizes amylose. The starch of the present invention therefore may be viewed as a reduced amylose starch or a special type of waxy starch with new elastic properties. The starch of the present invention is referred to herein as waxy-E or wx-E starch, to emphasize this elastic property not previously available with known waxy starch. In particular, the starch of the present invention has special properties of high viscosity and valuable paste and gel properties not previously found in natural i.e., wild type) starches or waxy starches of plants of similar species. The special properties of the starches of the present invention are believed to be the product of the unique combination of reduced amylose content of the starch of the present invention, as compared to starch of a wild type plant of the same species, and a similar amylopectin structure of the starch of the present invention, as compared to starch of a wild type plant of the same species. While these special properties have been characterized herein using a Rapid Fisco Analyzer, one of ordinary skill in the art will appreciate that other means are available to characterize the physical properties which may be used to describe the presently disclosed starch. The starch of the present invention may be obtained from plants and/or plant parts through mutagenesis or by plant transformation or other approaches known in the art to reduce the amylose content of plants without affecting amylopectin structure and without reducing amylose content as significantly as is found in waxy starches which have little or no amylose. Further, the invention relates to a method of increasing the elasticity of a formulation by utilizing a waxy-E starch of the present invention. [0003] Chemically, starch can be described as a mixture of two homoglucose polymers: amylose and amylopectin. Amylose is a generally linear .alpha.-1,4 glucan which sometimes is lightly-branched with .alpha.-1,6-glycosidic linkages. Amylopectin is normally larger than amylose and is highly-branched with .alpha.-1,6-glycosidic linkages. The balance of amylose and amylopectin in normal starches isolated from storage tissues like potato tubers or cereal grain is normally between 20 to 30 percent amylose and the remainder 70 to 80 percent is described as amylopectin on a dry starch weight basis. [0004] Plants displaying altered starch storing organ phenotypes have been important in advancing our understanding of how starch is produced in plants. For example, numerous phenotypes have been reported for amize (Glover and Mertz, 1987, Corn, in Agronomy. American Society of Agronomy, Madison; Coe et al, 1988, The genetic of corn, in Corn and Corn Improvement, 3.sup.rd edition, G. F. Sprague and J. W. Dudley, eds. American Society of Agronomy, Madison) and several phenotypes (e.g., waxy, amylose extender, dull, shrunken, sugary-2, and sugary) have been described extensively with regard to their effects on carbohydrate composition and response to genetic background, allelic dosage, or interaction with other mutations (example references: Creech, 1965, Genetics 52:1175-1186; Holder et al, 1974, Crop Science 14:643-646; Garwood and Vanderslice, 1982, Crop Science 22:367-371; Garwood et al, 1976, Cereal Chemistry 53:355-364). Many studies of starch storing organ phenotypes have focused on the molecular structure of synthesized polysaccharides and the concentration and type of soluble carbohydrates found in the starch storing organ during early-to-mid development. In particular, examination of maize starch storing organs with differing phenotypes have been instrumental in characterizing carbohydrate metabolism in cereal grain and determining which enzymes have a role in regulating starch biosynthesis (for review see Boyer, 1985, Phytochemistry 24:15-18; Shannon and Garwood, 1984, Starch: chemistry and Technology; R. L. Whistler, J. N. BeMiller, and E. F. Paschall, eds; Academic Press, Orlando). [0005] Across all plants, one starch storing organ phenotype produces a starch which contains a low quantity of amylose. This phenotype is called "waxy" starch for historical reasons: in maize the phenotype of the intact seed has a waxy phenotypic appearance. Plants producing waxy starch are often referred to as waxy plants or waxy mutants; the gene is commonly referred to as the waxy gene. Granule bound starch synthase [GBSS-ADPglucose: 1,4-.alpha.-D-glucan-4-.alpha.-D-glucosyltransferase (E.C.2.4.1.21)] enzyme activity is strongly correlated with the product of the waxy gene (Shure et al, 1983, Cell 35: 225-233). The synthesis of amylose in a number of species such as maize, rice and potato has been shown to depend on the expression of this gene (Tsai, 1974, Biochemical Genetics 11: 83-96; Hovenkamp-Hermelink et al, 1987, Theoretical and Applied Genetics 75: 217-221). Visser et al described the molecular cloning and partial characterization of the gene for granule-bound starch synthase from potato (1989, Journal of Plant Science 64:185-192). Visser et al (1991, Molecular and General Genetics 225289-296) have also described the inhibition of the expression of the gene for GBSS in potato by antisense constructs. Further, starch synthases (EC 2.4.1.11 and EC 2.4.1.21) elongate starch molecules (Delrue et al, 1992, Bacteriology 174:3612-3620; Denyer et al, 1999a, Biochemical Journal 340:183-191; Denyer et al, 1999b, Biochemical Journal 342:647-653) and are thought to act on both amylose and amylopectin. Starch synthase [SS-ADP glucose: 1,4-.alpha.-D-glucan-4-.alpha.-D-glucosyltransferase (EC2.4.1.11)] activity can be found associated both with the granule an in the stroma of the plastid. The capacity for starch association of the bound starch synthase enzyme is well known. Various enzymes involved in starch biosynthesis are now known to have differing propensities for binding as described by Mu-Forster et al (1996, Plant Physiology 111:821-829). The other SS enzymes have become known as soluble starch synthases, following the pioneering work of Frydman and Cardini (Frydman and Cardini, 1964, Biochemical and Biophysical Research Communications 17:407-411). Recently, the appropriateness of the term "soluble" has become questionable in light of discoveries that these enzymes are associated with the granule as well as being present in the soluble phase (Denyer et al, 1993, Plant Journal 4:191-198; Denyer et al., 1995, Planta 97:57-62; Mu-Forster et al., 1996, Plant Physiology 111:821-829). It is generally believed that the biosynthesis of amylopectin involves the interaction of soluble starch synthases and starch branching enzymes. Different isoforms of soluble starch synthase have been identified and cloned in pea (Denyer and Smith, 1992, Planta 186:609-617; Dry et al, 1992, Plant Journal, 2:193-202), potato (Edwards et al, 1995, Plant Physiology 112:89-97; Marshall et al, 1996, Plant Cell 8:1121-1135) and in rice (Baba et al, 1993, Plant Physiology 103:565-573), while barley appears to contain multiple isoforms, some of which are associated with starch branching enzyme (Tyynela and Schulman, 1994, Physiologica Plantarum 89:835-841). In maize, two soluble forms of SS, known as isoforms I and II, have been identified (Macdonald and Preiss, 1983, Plant Physiology 73:175-178; Boyer and Preiss, 1978, Carbohydrate Research 61:321-334; Pollock and Preiss, 1980, Archives of Biochemistry and Biophysics 204:578-588; Macdonald and Preiss, 1985 Plant Physiology 78: 849-852; Dang and Boyer, 1988, Phytochemistry 27:1255-1259; Mu et al, 1994, Plant Journal 6:151-159), but neither of these has been cloned. SSI activity of maize endosperm was found to be correlated with a 76-kDa polypeptide found in both soluble and granule-associated fractions (Mu et al., 1994, Plant Journal 6:151-159). The polypeptide identity of SSII remains unknown. [0006] Waxy maize starch which contains essentially no amylose has been known for many years (Shannon and Garwood, 1984; Starch: Chemistry and Technology; R. L. Whistler, J. N. BeMiller, and E. F. Paschall, eds; Academic Press, Orlando; pp 50-56). There are examples of such waxy starches in peas, maize, rice, potato, sorghum, wheat, barley and other plants. [0007] For many plants including wheat, pleas, corn, and potatoes among others, a principal purpose for their domestication and cultivation is for starch production. The utilization of the starch may be in the form of the intact starch storing organ itself (e.g., a baked potato) or as a preparation of a substantially complete starch storing organ (e.g. flour or meal or sliced potatoes). Alternatively, the starch may be isolated from starch storing organs for incorporation into foodstuffs (e.g. pie fillings, puddings, soups, sauces, gravies, coatings, candies and/or confectionary products, and/or yoghurts and other dairy products) and/or industrially-derived products (e.g. paper sizing aids, textile sizing aids, and/or suspension aids). Starch is produced in plants as granules: microscopic structures with spherical, elliptical, or polyhedral shapes which contain individual starch molecules. [0008] Examination of the color that starch stains with the addition of iodine is one of the simplest methods of identifying waxy starches. When stained with iodine, normal starch will stain blue or purple. A waxy starch will be red or brown or brownish-red in color when stained with iodine because the amylose component is severely reduced such that there is little, or essentially no amylose present. Waxy starches have been consistently described as (a) nearly 100% amylopectin or (b) isolated from plant starch storage organs which lack a GBSS enzyme in the endosperm or (c) from plant starch storage organs which have originated from a plant which produces a starch which is nearly 100% amylopectin or (d) from plant starch storage organs which have originated from a plant which lacks a GBSS enzyme in the endosperm or (e) having some or all of these qualities or (f) having unknown or undocumented quality (U.S. Pat. Nos. 4,428,972; 4,615,888; 4,767,849; 4,789,557; 4,789,738; 4,801,470; 6,143,963). [0009] Some waxy starches might stain blue or purple and may appear to contain some amylose as a result of changes in amylopectin structure. For example, in maize long-chain amylopectin is produced due to the decrease in starch branching enzyme activity as a result of the amylose-extender mutation in the starch biosynthetic pathway (Boyer et al, 1976, Journal of Heredity 67:209-214). Waxy amylose-extender starch, a starch which is produced in plants having both waxy and amylose-extender mutations, may have an apparent amylose content of 15% to 26% (Shannon and Garwood, 1984; Starch: Chemistry and Technology; R. L. Whistler, J. N. BeMiller, and E. F. Paschall, eds; Academic Press, Orlando; p 65). The differences in the structure of waxy starch and waxy amylose-extender starch, and the effects of the amylose-extender mutation on starch in general, are clearly observed in the distribution of their component chains (Jane et al, 1999, Cereal chemistry 76:629-637). This, and other alterations of the starch biosynthetic pathway, have an effect on amylopectin starch structure and starch cooking, gelling, pasting, and in general, starch Theological properties. [0010] Thus, starch granules, which have a blue coloration, contain long chains. The long chains may either be real amylose or a component of the amylopectin of the starch as a result of an alteration in the starch biosynthetic pathway (e.g. the amylose-extender mutation in maize), resulting in an apparent amylose content by some methods and no amylose by others (Klucinec and Thompson, 1998, Cereal chemistry 75:887-896). Additionally, amylopectin and waxy starch may appear to have an amylose content of 5% itself by quantitative iodine staining methods. This amylose may be attributed to the low iodine binding capacity of the amylopectin and may be falsely attributed to amylose when the iodine binding capacity of the amylopectin is not taken into consideration during measurements (Knutson and Grove, 1994, Cereal Chemistry 71:469-471). [0011] Much time and effort has been spent to produce waxy starch, which stains red by virtue of the fact that in this form it has very little amylose. Waxy starch and normal starch differ in the way they change during a cooking process. Heating starch in water or an aqueous solution results in changes in the starch granules (Whistler and Daniel, 1985, Carbohydrates, in Food Chemistry, O. R. Fennema, ed., Marcel Dekker, Inc., New York, pp. 114-115). During heating, granules swell and the organized structures maintaining the granule structure dissociate, permitting further swelling. With additional heating and applied shear forces, granules will eventually collapse to form an unorganized paste of starch molecules. This process of starch granule swelling and dissociation, known as gelatinization, is known to those familiar with the art (Atwell et al, 1988, Cereal Foods World 33(3):306-311; Tester and Morrison, 1990, Cereal Chemistry 67:551-557). Upon cooling, starch begins to reorganize into structures resembling those which originally held the starch granules together, however the complete highly organized structure of the granule is never reestablished. This process of reorganization, known as retrogradation, is well known to those familiar with the art (Atwell et al, 1988, Cereal Foods World 33(3):306-311). Retrogradation often involves changes in the physical properties of the starch paste, including a decrease in paste clarity and gelation of the paste. Normal starches are generally recognized for their ability to gel within hours (Ring, 1985, Starch/Starke 37; 80-83), while waxy starches are generally recognized for their ability to require weeks to gel if they gel at all (Yuan and Thompson, 1998, Cereal Chemistry 75:117-123; Biliaderis, 1992, Characterization of starch networks by small strain dynamic oscillatory rheometry, in Developments in Carbohydrate Chemistry, R. J. Alexander an H. F. Zobel, eds., American Association of Cereal Chemists, St. Paul, p 103). Normal starches are generally recognized for forming opaque pastes and gels, while waxy starches are generally recognized for remaining transparent after processing (Craig et al, 1989, Cereal Chemistry 66:173-182). Waxy starches are considered useful as water binders, viscosity builders, and texturizers in food as well as industrial applications (Reddy and Seib, 2000, Journal of Cereal Science 31:25-39). Waxy starches also have better freeze-thaw stability and clarity compared to normal starches once cooked (Whistler and BeMiller, 1997, Carbohydrate chemistry for Food Scientists, Eagan Press, St. Paul, p. 146; Reddy and Seib, 2000, Journal of Cereal Science 31:25-39). Waxy starches are also less resistant to shear, acid, and high temperatures than are normal starches, and extended cooking of waxy starches results in stringy, cohesive pastes (Whistler and BeMiller, 1997, Carbohydrate chemistry for Food Scientists, Egan Press, St. Paul, p. 142; Reddy and Seib, 2000, Journal of Cereal Science 31:25-39). These characteristics of waxy starch are believed to be a result of the molecular characteristics of the starch, specifically the absence of amylose (Whistler and Daniel, 1985, Carbohydrates, in Food Chemistry, O. R. Fennema, ed., Marcel Dekker, Inc., New York, p. 113), though the precise behavior of the starch also depends on the concentration of the starch and the conditions under which it is processed and subsequently stored. Finally, it is generally recognized that it is common for waxy starch to be chemically modified by substitution, crosslinking, or both, to improve its stability to temperature, shear and acid as well as to minimize its undesirable paste qualities (Whistler and Daniel, 1985, Carbohydrates, in Food Chemistry, O. R. Fennema, ed., Marcel Dekker, Inc., New York, pp. 118-120). Such practices are common to those familiar with the art (Zheng, G. H. et al, 1999, Cereal Chemistry 76:182-188; Reddy ad Seib, 2000, Journal of Cereal Science 31:25-39). [0012] By eliminating other key starch biosynthesis enzymes, other alterations of the starch biosynthetic pathway can result in useful starches. Several patents exist on the creation and use of such starches (U.S. Pat. Nos. 4,428,972; 4,615,888 4,767,849; 4,789,557; 4,789,738; 4,801,470; 5,009,911; and 5,482,560). More recently, several patents and published applications have described the production and utilization of heterozygous combinations of mutations in the starch biosynthetic pathway to obtain commercially useful starches (WO95/35026, U.S. Pat. Nos. 5,356,655; 5,502,270; and 5,516,939). The production of many of these starches involves the use of double or triple mutant plants. In these cases in which waxy starch is involved the inventors have stated that "plants homozygous recessive for the waxy gene lack a granule bound starch synthase [GBSS] enzyme and produce nearly 100% amylopectin" (U.S. Pat. Nos. 5,356,655; 5,502,270). Due to the number of mutations required to sufficiently alter the starch (at least 2 or 3 within a single plant) many of these starches are difficult and costly to produce commercially, so many of these starches from plants with mutations in the starch biosynthetic pathway are uncompetitive with chemically modified starches. Further, these combinations of 2 or more mutations, whether they are combined homozygously or heterozygously in the plant endosperm, rely on the alteration of the structure of amylopectin from normal or waxy starch. [0013] Waxy potato starches have been shown to contain an amylose content as low as 0% and as high as 7.9% (Salehuzzaman et al, 1999, Plant, Cell, and Environment 22:1311-1318, van der Leij et al, 1991, Theoretical and Applied Genetics 82:289-295). However, the amylose content of all of these starches is regarded as zero (van der Leij et al, 1991, Theoretical and Applied Genetics 82:289-295). Hovenkamp-Kermelink et al (1987, Theoretical and Applied Genetics 75:217-221) produced a waxy mutant of potato by screening microtubers produced from plants exposed to X-ray radiation. The starch from two microtubers was found to have an amylose content of approximately 5%, but a second generation of tubers produced from additional microtubers from the same irradiated plants resulted in starch with a normal amylose content. Examination of an additional set of tubers resulted in three tubers, two of which stained a solid reddish-brown characteristic of the waxy mutation Neuffler et al, 1997, Mutants of Maize, Cold Spring Harbor Laboratory Press, Plainview, N.Y., p. 298) and a third which stained a mixture of reddish brown and blue indicating a heterogeneous mixture of waxy starch and amylose-containing starch of unknown quality within the potato tuber. The waxy potatoes did not produce a GBSS enzyme. No distinction was made between these starches with an amylose content below 3.5%. Van der Leij et al (1991, Theoretical and Applied Genetics 75:217-221) observed that potato starches could have an amylose content of between 3% and 7.9% and the tubers would stain red with iodine stain, a primary characteristic of waxy starches. No distinctions were made between these starches having an amylose content between 3% and 7.9%. [0014] Studies have produced antisense transgenic potatoes having amylose contents between 3.0% and 8% (van der Leij et al, 1991, Theoretical and Applied Genetics 82:289-295; Visser et al, 1991, Molecular and General Genetics 225:289-296; Kuipers et al, 1994, Plant Cell 6:43-52) in further attempts to understand the function and activity of GBSS. The amylose contents of these starches were shown to be a result of tubers with both blue and red-brown staining portions (Visser et al, 1991, Molecular and General Genetics 225:289-296), indicating heterogeneous mixtures of waxy starch and amylose-containing starch of unknown quality. Kuipers et al (1994, Plant Cell 6:43-52) also observed heterogeneity on a granule level, with starch granules having blue cores and surrounded by a red-brown colored shell of starch, with the size of the blue core increasing in size with an increase in the amylose content of the starch. Further, the elastic properties and gelling abilities of pastes, and the gel properties of gels produced from these low amylose starches are unknown. Studies have attempted to restore the production of amylose in waxy potato plants by transforming the plants with genes for GBSS enzymes produced by other plants. Salehuzzman et al (1999, Plant Cell and Environment 22:1311-1318) partially restored amylose to amylose free mutants of potato to between 3.5% and 13% amylose by transformation with the cassaya GBSS enzyme with different amyloplast transit peptides. For starches between 3.5% and 13% amylose, the starches produced were heterogeneous mixtures of amylose-containing starch and red-brown staining waxy starch: the starch granules had blue cores surrounded by a red-brown colored shell of starch, with the size of the blue core increasing in size with increases in the amylose content of the starch (Salehuzzman et al, 1999, Plant Cell and Environment 22:1311-1318). Salehuzzaman et al (1999, Plant Cell and Environment 22:1311-1318) additionally observed that a paste of a potato starch with an apparent amylose content of 13% developed an elastic modulus during cooling while a paste of a waxy potato starch did not; the elastic behavior of the heterogeneous starches with lower amylose contents were not reported. Waxy potatoes transformed with GBSS isoforms from pea resulted in potatoes with amylose contents of between 0.8% an 1%, and like the other low amylose potatoes and pea starch, heterogeneity was observed within the granules: granules stained with iodine stain revealed amylose in concentric rings or having blue-staining granule cores (Edwards et al, 2002, The Plant Cell 14:1767-1785). The presence of the amylose produced by pea GBSS was claimed to have an effect on the cooking properties of the starch (Edwards et al., 2002, The Plant Cell 14:1767-1785), however the differences observed between the starches are within the error associated with this type of instrumental measurement. Flipse et al (1996, Theoretical and Applied Genetics 92:121-127) extracted starch from plants produced from crosses between a waxy potato and a normal potato; the potato tubers had varying levels of GBSS activity and no linear correlation was observed between GBSS activity and amylose content. Starches with amylose contents of 2.50%, 16.94%, 18.96%, and 20.32% were examined for their swelling properties and the rheological properties of swollen starch granules. No clear differences of the effect of amylose were observed in the swelling and rheological properties of the granules. The only conclusion that could be made was that the presence of amylose (above 16.94%) had an influence on the physical behavior of the granules. [0015] Thus, in potato, reduction in the amylose content of the starch has resulted in the production of heterogeneous mixtures of amylose-containing starch and waxy starch, with heterogeneity among a population of starch granules and within individual starch granules. Further, no distinctions in the physical properties of waxy starches with amylose contents between 0% and 7.9% have been made. Thus, from the existing literature it may be inferred that for potato starch, amylose contents of less than 7.9% confer no unique Theological or pasting properties to these starches outside of those properties observed for either waxy potato or normal potato starch. Further, the elastic properties and gelling abilities of pastes, and the gel properties of gels produced from starches below 13% amylose are unknown, and those tests which have been conducted indicate that the physical properties are within the error associated the physical properties of waxy potato starch or a potato starch with a normal amylose content. [0016] Like the transgenic potato starches, pea mutants producing starch with amylose contents lower than normal pea starch produced granule with blue cores and a red-brown periphery (Denyer et al, 1995, Plant Cell and Environment 18:1019-1026), indicating that they were heterogeneous mixtures of amylose-containing starch and waxy starch. Cooking, paste, and gel behavior was not reported for these starches. [0017] Extensive work initially in Japan has identified waxy wheat starches. The range of amylose content of these waxy mutants was narrow, being approximately 0.5% difference between the highest level and the lowest level reported. In all cases the starch was reported as staining red with iodine and the amylose content was reported as zero or near zero percent. A waxy wheat starch was also created using mutagenesis of a double-null wheat known as "Ike" to generate a non-null wheat (WO09815621) which stained red when tested with iodine stain. A null allele does not produce a certain protein at that allele on a certain chromosome, and a null mutant does not produce a certain protein at any of the chromosomes. This is in contrast to a non-null mutant which does produce the protein. Further work with transgenic lines has found that disruption of the waxy gene using antisense technology can produce lines lacking in amylose. In all cases these lines were screened for iodine coloration and red-brown staining starches were found and selected out of the transformants. [0018] Miura and Sugawara (1996, Theoretical and Applied Genetics 93:1066-1070) have shown that substitution of genes producing functional GBSS enzyme with the null alleles can result in starches with a 22 to 23% amylose content rather than the 25.5% amylose content of the normal control. Likewise, Miura et al (1999, Euphytica 108:91-95) have shown that elimination of the functionality in two of the three GBSS enzyme isoforms in wheat endosperm results in a wheat starch which has an amylose content of at least 16% and more often between 20% and 21% of the normal 25% amylose present in the starch. Thus, the presence of one wild type GBSS enzyme is sufficient to produce a starch with an amylose content of at least 16%. Oda et al (1992, Japanese Journal of Breeding 42:151-154) has shown that low amylose wheat starches having an amylose content between 14.1 and 16.7% can be created through ethyl methanesulphonate (EMS) mutagenesis of the seeds. Sasaki et al (2000, Cereal Chemistry 77:58-63) produced wheat starches with amylose contents of about 7.5% and 13.5% by crossing normal wheat with waxy wheat. Peak viscosities of all starches differed by less than 20% of the peak viscosity of the waxy wheat starch, with the low amylose starches having a higher peak viscosity than both normal and waxy wheat starch. The gelatinization temperatures and enthalpy were highest for waxy wheats and decreased in the order waxy>13.5% amylose wheat>7.5% amylose wheat>normal wheat starch. The retrogradation temperatures and enthalpy were insignificantly different for waxy wheat, normal wheat, or any of the low amylose wheat starches. From retrogradation data, the inference that these low amylose wheat starches exhibit unique Theological properties could not be made. Further, the elastic properties and gelling abilities of pastes, and the gel properties of gels produced from any of these low amylose starches are unknown. Additionally, in this case since the low amylose trait is not fixed in one wheat line, but instead is the product of two lines with widely differing amylose contents, the resultant low amylose seed if grown will not produce seeds with one type of low amylose starch but instead will produce a mixture of seeds containing starch having a range amylose contents varying widely between those of the original waxy and normal parents. These starches made from crosses of normal plants and waxy plants are not the subject of the present invention. [0019] Kiribuchi-Otobe et al (1998, Cereal Chemistry 75:671-672) found that starch granules extracted from a wheat strain derived from mutagenized Tanikei A6099 had an apparent amylose content of 1.6% and stained dark brown with dark cores compared to red-staining waxy wheat starch (0.4% apparent amylose). This same wheat was claimed to have an amylose content of 0.8% to 2.5% in U.S. Pat. No. 6,165,535 to presumably account for the approximately 1% error associated with the amylose content assay. Kiribuchi-Otobe et al (1998, Cereal Chemistry 75:671-672) found that this mutant wheat starch had an initial high temperature viscosity stability relative to a waxy wheat starch (0.4% amylose). However, the viscosity of the starch paste decreased dramatically, to the same viscosity as the waxy wheat, during continued cooking and remained at the same viscosity as waxy wheat after cooking. The mutagenized Tanikei A6099 wheat is known to produce a mutant GBSS enzyme (Yanagisawa et al, 2001, Euphytica 121:209-214), but the effect of the mutation on the activity of the enzyme is not known (Yanagisawa et al, 2001, Euphytica 121:209-214). Additionally, it is unknown whether the starch contains true amylose, which normally would result in a blue coloration with iodine stain rather than a dark brown stain for this mutant starch, or contains a modified amylopectin structure. The act of mutagenesis itself may have created other mutations in the plant genome which could have additional effects on biosynthesis and thus the cooking properties of the starch (e.g. the amylose-extender mutation in maize), and the structure of amylopectin is also clearly known to have a significant impact on the paste and gel properties of a starch (Jane et al, 1999, Cereal Chemistry 76:629-637). These other enzymes are known to those working in the area of starch biosynthesis, biochemistry, and chemistry. Further, it has been suggested that GBSS may influence the structure of amylopectin as well (Martin and Smith, 1995, The Plant Cell 7:971-985), and a mutation in GBSS could conceivably result in an enzyme which preferentially produces an altered amylopectin rather than synthesize amylose. Thus, alteration of the amylopectin structure of the starch may also affect starch cooking and rheological properties. Kiribuchi-Otobe and colleagues (U.S. Pat. No. 6,165,535; Kiribuchi-Otobe et al, 1998, Cereal Chemistry 75:671-672; Yanagisawa et al, 2001, Euphytia 121:209-214) have not shown that their plants produce an active GBSS nor have they shown that their starch contains amylose and/or produces a normal wheat amylopectin. Further, the elastic properties and gelling abilities of pastes, and the gel properties of gels produced from this low amylose wheat starch are unknown. [0020] Thus, in wheat lines, reduction in the amylose content of the starch has resulted in the production of heterogeneous mixtures of brown-staining starch of unknown amylose and amylopectin quality relative to normal wheat starch. Further, no distinctions in the rheological properties of starches with amylose contents between 1.6% and 15% have been made. Thus, from the existing literature the rheological properties of starches with amylose contents between 1.6% and 15% from hybrid wheat plants are unknown. Some evidence suggests that wheat starches having 7.5% or 13.5% amylose may have some unique cooking properties, but production of these starches was a result of hybridization and recombinations of genetics which cannot be carried uniformly into future generations of material. Further, the elastic properties and gelling abilities of pastes, and the gel properties of gels produced from wheat starches below 1.6% and 15% amylose are unknown. [0021] Low amylose sorghum starches have been shown to contain up to approximately 5% apparent amylose, though these low amylose sorghum starches are commonly referred to as waxy sorghum starches. Horan and Heider (1946, Cereal chemistry 23:492-503) indicated that some waxy sorghum starches had an amylose content as high as 5%, however they admitted that the method they utilized to determine the amylose contents was primarily used to differentiate waxy from normal sorghum starch and was a rapid method subject to large errors. Miller and Burns (1970, Journal of Food Science 35:666-668) also found waxy sorghums to contain up to approximately 5% amylose, and no distinction was made between this 5% amylose starch and the waxy sorghum starches with amylose contents below 1%. Thus, it may be inferred that for sorghum a small quantity of amylose apparently confers no special cooking or rheological qualities to these starches. [0022] Waxy starches and low amylose rice starches have been shown to contain between 0% and 3% amylose, though collectively these starches are referred to as waxy rice starches (Reyes et al, 1965, Journal of Agricultural and Food Chemistry 13:438-442; Juliano et al, 1969, Journal of Agricultural and Food Chemistry 17:1364-1369; Sanchez et al, 1988, Cereal chemistry 65:240-243). With these waxy rice starches, it has been assumed that the differing cooking and paste properties of these starches are due to differences in the structure of the amylopectin of the starch rather than the amylose content of the starch (Wang and Wang, 2002, Cereal Chemistry 79:252-256). Thus, it may be inferred from the literature that for rice, reduced levels of amylose compared to normal starches confers no special cooking or other rheological qualities to these starches. The effects of amylose and other molecular and compositional characteristics of rice starches on rice (Champagne et al, 1999, Cereal Chemistry 76:764-771; Bett-Garber et al, 2001, Cereal Chemistry 78:551-558) or rice starch properties remain unclear (Lai et al, 2000, Cereal Chemistry 77:272-278). [0023] Low amylose rice starches have been shown to have amylose contents between 7% and 15% (Kumar and Khush, 1988, Euphytica 38:261-269). Shimada et al (1993, Theoretical and Applied Genetics 86:665-672) produced several antisense rice plants with starch having amylose contents between 6% and 13%. The iodine staining qualities of these starch granules were not reported. Further, any cooking properties of the starches, the elastic properties of gels produced from these low amylose rice starches produced by transgenic rice plants are unknown. [0024] Sano (1984, Theoretical and Applied Genetics 68:467-473) and Sano et al (1986, Euphytica 35:1-9) investigated the effects of two alleles on the gene expression at the waxy locus in rice. The Wx.sub.b allele was shown to relate to ineffective production of GBSS enzyme and amylose, while the Wx.sub.a allele was shown to produce larger quantities of GBSS enzyme and amylose. Villareal et al (1989, Starch 41:369-371) also showed that the Wx.sup.a allele was less effective in the production of amylose than the Wx.sup.b allele based on analysis of 40 rice varieties. Additionally, Isshiki et al (1998, Plant Journal 15:133-138) observed that for two wild-type rice alleles, Wx.sup.a and Wx.sup.b, Wx.sup.b had a GBSS activity tenfold lower than Wx.sup.a at the protein and mRNA levels. The decrease in the activity of Wx.sup.b compared to Wx.sup.a was the result of a point mutation within the genetic sequence for the normal rice enzyme (Wx.sup.a allele). The Wx.sup.b allele resulted in the synthesis of a 3.4 kilobase pair mRNA transcript compared to a 2.3 kilobase pair mRNA transcript for Wx.sup.a as a result of the inclusion of an intron into the mRNA sequence as a result of the point mutation. Starch produced from rice plants was related to the ability of the plant to excise the intron from the mRNA sequence. Plants which expressed high levels of mature mRNA (without intron 1) and no pre-mRNA (containing intron 1) produced the highest levels of GBSS protein and the highest levels of amylose (20.0 to 27.8% amylose). With more balanced expression of mature and pre-mRNA, lower levels of GBSS protein and amylose were observed (6.7 to 16.0% amylose). When all of the mRNA contained intron 1, and no mature mRNA was observed, no GBSS protein was observed and no amylose was detected (Wang et al, 1995, Plant Journal 7:613-622). This pattern relating amylose content to mature mRNA with properly excised intron 1 could be applied across 31 different rice cultivars (Wang et al, 1995, Plant Journal 7:613-622). Thus based on the work of Shimada et al (1993, Theoretical and Applied Genetics 86:665-672), Isshiki et al (1998, Plant Journal 15:133-138), and Wang et a (1995, Plant Journal 7:6213-622), low amylose rice appears to be the result of a decrease in the amount of normal GBSS through a mutation which results in problems with mRNA processing rather than due to a mutation in the mature mRNA sequence. Further, no clear relationships exist between rice and rice starch properties and amylose content. Continue reading about Starch... Full patent description for Starch Brief Patent Description - Full Patent Description - Patent Application Claims Click on the above for other options relating to this Starch patent application. ###  How KEYWORD MONITOR works... a FREE service from FreshPatents1. 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