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This study aimed to characterize the interactions between cereal flour (rice, wheat, and barley) and "nata puree" (NP), a disintegrated bacterial cellulose (BC) in the presence of a water-soluble polysaccharide, with powder-dispersion activity. Pasting properties of cereal flour with additives were analyzed using a Rapid Visco Analyzer, and disintegrated BC in water (BCW), three water-soluble polysaccharides: (1,3)(1,4)-β-glucan, tamarind seed gum, and birchwood xylan, and the corresponding NPs were used as additives. For rice flour, additional BCW or NPs increased the initial and the peak viscosity. The addition of water-soluble polysaccharides produced the opposite trend: viscosity increased from the peak time to the end of measurements. For wheat flour, the addition of BCW or NP delayed the peak time and increased peak viscosity; the increase was maintained till the end of measurements. For barley flour, the additional BCW or NP caused a higher gelatinization rate and increased viscosity at the starch-retrogradation stage. Next, static gelatinization of a rice flour suspension in NP was successfully accomplished before placing it in a vessel; NP concentration in the gel significantly affected the firmness. Thus, the dynamic and unique interactions between various cereal flours and cell-wall polysaccharides in NPs can increase the flours' potential; static gelatinization of cereal flour with NP could expand flours' application range in both current and next-generation cooking.

Pulverization is a potentially powerful solution for the resource management of surplus- and non-standard agricultural products, maintaining their nutritional values for long and ensuring their homogeneity, whereas their original textures could disappear to narrow the application ranges. Therefore, new technologies should be developed for reconstructing the powders to provide them with new physical characteristics. Herein, we developed a novel food material, nata puree (NP), by nata de coco (bacterial cellulose gel) disintegration with a water-soluble polysaccharide using a household blender. The process worked well with (1,3)(1,4)-β-glucan (BGL) as the polysaccharide, which could be substituted with barley extract. Lichenase treatment of the NP dramatically modified its physical properties, suggesting the importance of the BGL polymeric forms. NP exhibited distinct potato powder and starch binding activities, which would be attributed to its interactions with the cell wall components and a physical capture of powders by the NP network, respectively. NP supplementation into the potato paste improved its firmness and enabled its printable range shift for 3D food printing to a lower powder-concentration. NP also promoted the dispersion of powders in its suspension, and designed gelation could also be successfully performed by the laser irradiation of an NP suspension containing dispersed curdlan and turmeric powders. Therefore, NP could be applied as a powder modifier to a wide range of products in both conventional cooking, food manufacturing, and next generation processes such as 3D food printing.

BEIIb plays a specific role in determining the structure of amylopectin in rice endosperm, whereas BEIIa plays the similar role in the culm where BEIIb is absent. Cereals have three types of starch branching enzymes (BEs), BEI, BEIIa, and BEIIb. It is widely known that BEIIb is specifically expressed in the endosperm and plays a distinct role in the structure of amylopectin because in its absence the amylopectin type changes to the amylose-extender-type (ae-type) or B-type from the wild-type or A-type and this causes the starch crystalline allomorph to the B-type from the wild-type A-type. This study aimed to clarify the role of BEIIa in the culm where BEIIb is not expressed, by using a be2a mutant in comparison with results with be2b and be1 mutants. The results showed that the amylopectin structure exhibited the B-type in the be2a culm compared with the A-type in the wild-type culm. The starch granules from the be2a culm also showed the B-type like allomorph when examined by X-ray diffraction analysis and optical sum frequency generation spectroscopy. Both amylopectin chain-length profile and starch crystalline properties were found to be the A-type at the very early stage of endosperm development at 4-6 days after pollination (DAP) even in the be2b mutant. All these results support a view that in the culm as well as in the endosperm at 4-6 DAP, BEIIa can play the role of BEIIb which has been well documented in maturing endosperm. The possible mechanism as to how BEIIa can play its role is discussed.

Rice-gel prepared by the following three steps: rice grain cooking, shearing of the cooked rice, and cooling for gel formation, is expected as a novel food ingredient for modification of various food products such as bread and noodles. To meet the demand for high-throughput systems for research and developments on the new rice gels, herein we established a mini-cooking system for preparation of rice gel samples from grains using a small-scale viscosity analyzer (Rapid Visco Analyzer; RVA). Polished rice grains (4 g) were cooked with 22 mL of water in a canister, and the paddle equipped in the canister was rotated at 2,000 rpm for 30 min (80 °C was used as a representative) to shear the cooked rice. The sheared paste was cooled to 10 °C at 160 rpm, and the initial gelation property was evaluated by viscosity analysis within the RVA. Alternatively, the sheared paste was transferred to an acrylic mold and kept at 4 °C for 0, 1, 3, and 5 days for determination of the hardness with a compression test. Compressive forces required to penetrate 20 % thickness for three tested rice cultivars were measured, and the trend of the value shifts during preservation is similar to the corresponding trend obtained in 300-g grain scale laboratory tests, whereas the individual values were halved in the former. This small cooking method could offer a useful assay system for a rapid evaluation in the breeding programs and in the high-throughput screening of additives for the modification of properties.

Ethanol precipitation process for purification of branched dextrin (BD) in Nageli amylodextrin from waxy rice starch was developed. Temperature and ethanol concentration for precipitation were main parameters affecting the recovery and purity of BD, and the purification condition at 4 °C and 10 % (v/v) ethanol in water was adopted. After four-time precipitation, the BD recovery was 34.6 %, whereas the purity improved from 78.5 % at the initial to 94.5 % at the four-time purified BD (BD4). BD4 mainly showed a chain length distribution between 18 to 35 with a mode length of 25, which shifted after enzymatic debranching with isoamylase to that between 9 and 20 with a mode length of 14. Each purified BD was solubilized in water, and each solution was mixed with methanol-water at 25 °C to a final methanol concentration of 16 M. The flakes of BD precipitated with 16 M methanol exhibited an A-type crystal structure by an X-ray diffraction analysis, and the speed generation of white flakes in 16 M methanol dramatically increased as the purification time increased. The effect of addition of highly branched cyclic dextrin (HBCD) or sodium tetraborate on BD aggregation in 16 M methanol was also investigated, where the former retarded aggregation but the latter had no effect on the velocity. Thus, the purified BD enables rapid characterization of aggregation of double helix structures of A-type crystal structure, and screening of compounds which could affect the phenomena for prediction of potentials in starch modification as well.

The objective of this study was to investigate the effects of rice variety, water content, and preparation temperature on the textural properties of gels processed from cooked rice grains via high‐speed shear homogenization. Rice gels were prepared from seven high‐amylose rice varieties. The results demonstrated the significant differences in rice gel hardness and hardening rates during storage based on the rice variety used. The proportion of short chains of amylopectin was negatively correlated with the hardness of the rice gel. The sample temperature before shear treatment also influenced the rice gel hardness. Rice gels prepared from cooked rice maintained at 75°C prior to homogenization showed a higher breaking force than those from cooked rice at 25°C. Observation using scanning electron microscopy demonstrated the tendency of the cooked rice sample maintained at 75°C to form a finer gel network after homogenization than those at 25°C from the same rice variety.

A simple method employing a commercially available canister was developed for the determination of mode of water absorption of rice flour samples. The samples prepared by four different grinding methods were used to analyze water absorption. The total amount of water in a flour sample was described by using an exponential model. Capacity and rate of water absorption of the samples were determined, and the relationship to baking quality of partially substituted rice bread was investigated. The water absorption was highly dependent on the method of grinding. Flours produced by wet jet-milling of the grains, which absorbed a small amount of water at high speed, were most suitable for rice bread. The method was applicable to other food powders, provided that flour particles do not stick together or swell immediately upon contact with water.

A newly developed sweet potato “Kyushu No. 159” (K159) was used as a feedstock for ethanol production in comparison with an ordinary type “Daichinoyume” (DCY). Gelatinization temperature of isolated K159 starch (49.5–66.2 °C) was approximately 20 °C lower than that of DCY starch (70.9–85.4 °C). The lower gelatinization temperature of K159 starch would be attributed to its higher proportion of short amylopectin branch-chains. Sweet potato mashes containing > 0.3 kg dm−3 total solids were prepared using enzymatic viscosity reduction, and utilized for liquefaction and simultaneous saccharification and fermentation (SSF). Ethanol productivity as a function of liquefaction temperature (50, 60, 70, 80, 90, and 100 °C) was investigated. The results showed that liquefaction at 60 °C was sufficient to efficiently accelerate SSF process of K159, and ethanol yields of 15.1–15.4 % (v/v) (88.8–90.6% of theoretical yield) were obtained during 48–72 h. In contrast, DCY mash required higher liquefaction temperature (90 °C) to achieve the similar ethanol yield. An estimate of environmental impacts in liquefaction process showed that K159 would provide approximately 50% reduction in energy consumption and CO2 emission compared with DCY. Accordingly, the specialized sweet potato “Kyushu No. 159” would offer an energy-saving alternative for fuel-ethanol production.

The present study was aimed to improve the efficiency of bioconversion process, namely the calcium capturing by carbonation at room temperature (RT-CaCCO) process. Rice endosperm starch was used as a model substance to observe the effects of lime treatments on the gelatinization of starch granules. Effect of subsequent carbonation and saccharification behaviors were also evaluated. With increasing lime concentration, significant rise in the gelatinization temperatures, and decrease in the gelatinization enthalpy were observed, suggesting enhanced granule stability and disruption of hydrogen bonds. These changes appeared to be leveling off near 9% lime concentration, at which the binding effect of calcium ions may be saturated. The mild heat treatment further promoted changes in gelatinization. It was postulated that it was not an annealing effect, but that mild heat treatment disrupted hydrogen bonds and provided more available sites for calcium binding. Carbondioxide (CO2) neutralization led to decrease in gelatinization temperatures. The optimum pretreatment conditions for efficient hydrolysis of mild heat treatment at 50°C for 24 h subsequent to lime pretreatment is effective in accelerating saccharification by 1.9-fold and CO2 neutralization should be carried out after heat treatment. This approach can be useful in improving the recovery of liberated glucose when applying the RT-CaCCO process to feedstocks which contain both starch and lignocellulosic material.

Summary High and low amylose Thai rice flours (KC and ML, respectively) were used in this work, to increase the resistant starch (RS) content in the flour. Pullulanase debranching followed by heat-moisture treatment (DHMT) altered the pasting properties, which increased the shear stability to the flours. The gelatinisation temperature determined by DSC was increased and the more retrogradation occurred in treated flour compared to the native flour. The SEM observation showed that the treatment did not change the morphology of the granules in both flours. The slowly digestible starch (SDS) content in DHMT KC was higher than in the native KC. The RS content in the treated ML flour was increased to 18.31% from 11.59% in native flour. These concluded that the treatment affected the digestibility, while maintaining the granular structure.

Rice plants are known to accumulate starch in leaf sheaths and culms, and in some cultivars significant amounts of starch are present at the mature stage. This can be considered as potential feedstock for the recovery of fermentable sugars. We isolated starches from the culms of cultivars Yumeaoba, Koshihikari, and Leafstar to investigate their structural and physical features. Yumeaoba culm starch contained 20.2% amylose, whereas Koshihikari and Leafstar contained 25.8% and 25.2%. Yumeaoba culm starch was found by chain-length distribution analysis to contain higher amounts of short chains, resulting in lower gelatinization temperature by 7 degrees C, as compared to Koshihikari and Leafstar. Consequently, the rate of enzymatic hydrolysis of Yumeaoba culm starches reached maximum at a lower temperature than Leafstar. Rice culm starch, with a lower gelatinization temperature, can provide an advantageous material for feedstock for bioethanol production in terms of energy conservation.

This paper discusses the sorption of cellooligosaccharides to activated clay in concentrated sulfuric acid solution. Cellobiose was sorbed to the clay in 72% (w/w) sulfuric acid but not in water; the sorption of glucose was not observed in both solutions. Hydrolysate of filter paper cellulose after 72% sulfuric acid treatment was also sorbed to the clay, and the sorbed sugars were partly released by diluting the mixture. The sorbed sugars could also be recovered in the form of d -glucose after hot dilute acid treatment of the sugar-acid-clay suspension.

Starch structural mutants showing abnormal endosperm characteristics have been used for investigating the effects of the mutation on structure and physicochemical properties of starches. Inbred lines of barley cultivars 'Shikoku Hadaka 97' and 'Glacier AC38' were used to investigate the impact of amo1 and waxy genes on starch properties. The amo1 type starch had high apparent amylose content and low starch content. The amo1+waxy type starch contained very little amylose. The content of long chains of amylopectin as detected with high-performance size-exclusion chromatography (HPSEC) was decreased, and that of amylopectin chains with the degree of polymerization (DP) of 12-36 was increased in amo1 and amo1 +waxy type starches. The amo1 and amo1 + waxy type starches exhibited high gelatinization temperatures and low gelatinization enthalpies.

Glucose production from cellulose flakes with cellulases was improved after pretreatment with saturated CaCl2 at room temperature. When pretreated microcrystalline cellulose flakes (Funacel II, Funakoshi Co., Ltd, Tokyo, Japan) were saccharified with the cellulases, 76.8% of the substrate was converted into glucose within 5 h, whereas the corresponding conversion rate of water-pretreated cellulose flakes was 33.8%. To clarify the mechanism of the promotion, cellobiohydrolase I purified from Trichoderma longibrachiatum was used as the model cellulase, which degraded CaCl2-pretreated cellulose more quickly than the water-pretreated cellulose under tested conditions. The maximum amount of the enzyme bound to CaCl2-pretreated cellulose at 37 degrees C was estimated as 1.14 nmol/mg of cellulose, whereas that to water-pretreated cellulose was 0.527 nmol/mg of cellulose. The specific activity of the bound enzyme greatly decreased with the increase of the surface density (rho) of the bound enzyme, and no significant positive effects of the CaCl2-pretreatment on the specific activity could be observed at the same rho value, suggesting that the promotion was attributed mainly to the increase of the surface area of cellulose. The effect was also observed with dewaxed cotton or filter paper, but not with nata de coco cellulose or bagasse cellulose as the substrates. This suggests that the CaCl2-pretreatment serves to increase the surface area of cellulose flakes via liberation of cellulose particles which were artificially aggregated during harsh drying processes of the flakes.

The baseline variation data on the chain-length distribution profiles of endosperm starch were acquired for use as a criterion for variation among bread wheat (Triticum aestivum L.) cultivars/lines. A total of 126 starch samples isolated from closely related species belonging to the Triticum-Aegilops group, i.e., five Triticum and 22 Aegilops species, were examined. Their side-chains were debranched by isoamylase and chain-length distribution profiles were determined by high-performance anion exchange chromatography with pulsed amperometric detection (HPAEC-PAD). An averaged chain-length distribution profile calculated from all data indicated that the most abundant side-chain had a degree of polymerization (DP) of 11 and its proportion based on relative peak area was 7.5%. The side-chains were classified into four groups, and the average proportions of each group were as follows; DP 6-12, 28.5% (range 26.3-30.9%); DP 13-24, 48.6% (46.2-50.8%); DP 25-36, 13.7% (12.8-15.2%) and DP ≥37, 8.9% (7.2-10.6%). The chain-length distribution profiles of Triticum and Aegilops species were essentially similar and no peculiar profile was observed. The range of the variation in the proportion of side-chain groups, however, was comparable to the difference between waxy and non-waxy bread wheat starches and among starches from wheat grown at different temperatures; this would affect the gelatinization and retrogradation properties of starch.

This paper reports on the influence of amylopectin chain length distributions on the gelatinization and retrogradation of starch. Wheat starch samples with different amylopectin chain length distributions were isolated, and the gelatinization and retrogradation phenomena of the samples were studied with differential scanning calorimetry (DSC). Wheat starch containing longer side chains of amylopectin (LCA) in higher ratios exhibited a sharper and deeper peak at higher temperatures in the heating DSC curve than did starch with low ratios. The retrogradation of starch was advanced with LCA. Although the re-gelatinization temperatures for retrograded starch varied slightly, the peak depth and enthalpy for re-gelatinization were higher with high ratios of LCA. For retrograded starch, each ordered region of amylopectin was not very different, however, more number of ordered regions was formed as the ratio of LCA of amylopectin increased.

The effects of amylose content and other starch properties on concentrated starch gel properties were evaluated using 10 wheat cultivars with different amylose content. Starches were isolated from grains of two waxy and eight nonwaxy wheat lines. The amylose content of waxy wheat lines was 1.4–1.7% and that of nonwaxy lines was 18.5–28.6%. Starch gels were prepared from a concentrated starch suspension (30 and 40%). Gelatinized starch was cooled and stored at 5°C for 1, 8, 16, 24, and 48 hr. The rheological properties of starch gels were studied by measuring dynamic viscoelasticity with parallel plate geometry. The low-amylose starch showed a significantly lower storage shear modulus (G′) than starches with higher amylose content during storage. Waxy starch gel had a higher frequency dependence of G′ and properties clearly different from nonwaxy starches. In 40% starch gels, the starch with lower amylose showed a faster increase in G′ during 48 hr of storage, and waxy starch showed an extremely s...

Mixed starches with an amylose content of 5, 10, 18, 20, 23, and 25% were prepared by blending starches isolated from waxy and non-waxy wheat at different ratios. The dynamic viscoelasticity of mixed 30% and 40% starch gels was measured using a rheometer with parallel plate geometry. The change in storage shear modulus (G') over time at 5 °C was measured, and the rate constant of G' development was estimated. As the proportion of waxy starch in the mixture increased, starch gels showed lower G' and higher frequency dependence during 48 h storage at 5 °C. Since the amylopectin of waxy starch granules was solubilized more easily in hot water than that of non-waxy starch granules, mixed starch containing more waxy starch was more highly solubilized and formed weaker gels. G' of 30% and 40% starch gels increased steadily during 48 h. 30% starch gel of waxy, non-waxy and mixed starches showed a slow increase in G'. For 40% starch gels, mixed starch containing more waxy starch showed rapidly developed G' and had a higher rate constant of starch retrogradation. Waxy starch greatly influenced the rheological properties of mixed starch gels and its proportion in the mixture played a major role in starch gel properties.

Ethyl methanesulphonate treatment of seeds from cultivar Kanto 107 lacking Wx-A1 and Wx-B1 proteins induced a mutant, named K107Afpp4, showing an altered flour-pasting profile, i.ea markedly increased viscosity at a low temperature and a decreased peak time in Rapid Visco Analyser measurement. The colour of the iodine complex of the isolated starch from the mutant remained bluish-purple but its λ max decreased to 584 nm from 601 nm shown by the wild type Kanto 107. The absorbance at 680 nm (blue value) of the mutant starch decreased to 0·206 from 0·324 for Kanto 107. The amylose content of K107Afpp4 starch was 12·7% measured by concanavalin A method, compared to 21·9% for the wild type. The apparent amylose content of the mutant starch measured by amperometric titration was 15·9% while that of Kanto 107 was 25·3%. Gel permeation chromatography showed that the mutant starch has a decreased amount of lower molecular weight fractions than starch from the wild type. Differential scanning calorimetry indicated that mutant starch has a higher gelatinisation peak temperature, 61·8 °C, than the wild type, 59·5 °C. The mutant will be useful as a genetic resource for altering wheat starch/flour properties and for clarifying the relationship between amylose content and wheat quality.

We studied the effect of amylose content on the gelatinization, retrogradation, and pasting properties of starch using wheat starches differing in amylose content. Starches were isolated from waxy and nonwaxy wheat and reciprocal F1 seeds by crossing waxy and nonwaxy wheat. Mixing waxy and nonwaxy wheat starch produced a mixed starch with the same amylose content as F1 seeds for comparison. The amylose content of F1 seeds ranged between waxy and nonwaxy wheat. Nonwaxy-waxy wheat had a higher amylose content than waxy-nonwaxy wheat. Endothermic enthalpy and final gelatinization temperature measured by differential scanning calorimetry correlated negatively with amylose content. Gelatinization onset and peak temperature clearly differed between F1 and mixed starches with the same amylose content as F1 starches. Enthalpy for melting recrystallized starches correlated negatively with amylose content. Rapid Visco Analyser measurement showed that F1 starches had a higher peak viscosity than waxy and no...

Two waxy endosperm mutant lines, K107Wx1 and K107Wx2, derived from a bread wheat cultivar, Kanto 107, had a lower flour yield in test milling and a lower peak temperature in flour pasting measurement than their parent. Starch content in the kernel of waxy mutants was low, while fat and (13),(14)-β-D-glucan content was high compared with cv Kanto 107, but protein content was similar for all of them. Waxy mutants had less α-amylase activity than their non-waxy parent, and had lower peak viscosity of flour paste in the pasting medium of water. A pasting test in silver nitrate solution increased peak viscosity in both waxy and non-waxy flours. The viscosity of waxy flour paste rapidly increased above 60°C, while that of non-waxy flour paste increased gradually at 60–80°C. The difference in pasting behaviour was attributed to the presence of amylose in starch granules. © 1999 Society of Chemical Industry

Starches were isolated from the endosperm of 12 wheat samples with a wide swelling power range in the wholemeal. Starch amylose content (24.8–34.2%) correlated negatively with the swelling power of isolated starch (18.3–26.9), but starch lipid content showed no such correlation. Higher proportions of long chains (DP ≥ 35) in amylopectins contributed to increased starch swelling. Native starch gelatinization temperatures and enthalpy measured by differential scanning calorimetry correlated positively with swelling power, which also correlated significantly with the regelatinization enthalpy of retrograded starches stored at 5°C for two and four weeks.

Starch was isolated from the endosperm of three recently developed waxy wheat lines and their parents. Their amylose and lipid contents, amylopectin structures and gelatinisation properties were evaluated. The endosperm starch from waxy wheat lines is composed essentially of amylopectin. The apparent amylose (1·2–2·0 g/100 g) and lipid contents (0·12–0·29 g/100 g) are much lower than the apparent amylose (26·0–28·4 g/100 g) and lipid contents (1·05–1·17 g/100 g) of their non-waxy parents. The amylopectin of waxy wheat lines is structurally identical to that of the parents. The peak gelatinisation temperature and gelatinisation enthalpy for waxy starch are significantly higher than for non-waxy starch, but the gelatinisation enthalpy for the amylopectin fraction of waxy starch is nearly identical to that of non-waxy starch.

小麦の品質評価の指標とするために,穀粒の硬軟質性と小麦粉の膨潤度の測定法を設定し,輸入銘柄,農林水産省登録品種,関東番号系統,オーストラリア品種を評価した.ASWは大きな膨潤度とやや大きな平均粒径に特徴が認められ,調査した範囲では,国内の品種系統でこれに相当するものは存在しなかった.しかし,チホクコムギ,関東107号および関東79号の膨潤度はASWと同じように大きいことが認められた.オーストラリア品種には,膨潤度が大きく,平均粒径も大きなものが存在した.

医療法人宏人会で血液透析中の慢性腎不全患者631例を対象に高解像度の探触子を用いて甲状腺の超音波検査を施行し, 213例 (33.8%) に嚢胞, 168例 (26.6%) に腫瘍を, さらに石灰化45例 (7.1%), 慢性甲状腺炎15例 (2.4%), 単純性甲状腺腫3例 (0.5%) 等の所見が得られた. 全体の有所見率は53.1%であり, 人間ドック等における健常人の報告 (13.5-22.3%) に比し有意に高率であった. 超音波所見上悪性が否定できず, 穿刺吸引細胞診を施行した77例中6例はclass III 以上の成績であり, うち4例と, 画像上強く悪性が疑われた3例の計7例で甲状腺全摘術が施行された. 組織診断は乳頭癌6例, 濾胞癌1例であった. 甲状腺癌の有病率 (9例, 1.4%) も健常者の報告 (0.04-0.5%) と比べ, 有意に高率であった. 以上の結果より, 血液透析患者では高率に甲状腺の病変が存在すること, さらに無症候性の甲状腺癌も認められたことから, 超音波検査は有用であると考えられた.

Two waxy bread wheat lines, KI07Wx1 and KI07Wx2, have been developed by treating cv. Kanto 107 seeds with ethyl methanesulphonate (EMS). About 2, 000 seeds of the cultivar were soaked for 4 hours in 0.5% EMS dissolved in 7% ethanol, and then 2, 000 seeds were sown in a green-house and 10, 634 M2 seeds were obtained from 1, 872 M1 plants. Cross sections of the distal endosperms of 4, 000 M2 seeds were stained with an iodine-potassium iodide solution, and two seeds stained red-brown. Since the M3 and M4 seeds derived from the remaining proximal halves of these two seeds showed the characteristic feature of waxy endo-sperm, the waxy endosperm character was considered to be genetically fixed in these two mutant lines, which were designated as KI07Wx1 and KI07Wx2. The amylose content of endosperm starch from both mutant lines was 0.9%, and no waxy proteins were detected in the starch of either line. The agronomic characters of KI07Wx1 and KI07Wx2 were very similar to those of cv. Kanto 107 grown under field conditions, except for the heading dates of the mutant lines and the 1, 000-grain weight of KI07Wx2. These results indicate that the mutagen treatment of seeds is effective in inducing of waxy, i.e. amylose-free, mutants when a bread wheat cultivar has a single waxy protein in their endosperm starch.

The effects of environmental temperature on gelatinization properties and amylopectin structures of wheat endosperm starch were examined by isolating starches from four wheat cultivars matured in growth chambers at daytime temperatures of 15, 20, 25, or 30°C. Kernel weight and starch content per kernel were reduced by high maturation temperature. Amylose content showed no significant change at high maturation temperature in some cultivars; in other cultivars, there was a slight increase. Principal component analysis of data on relative peak areas of debranched amylopectin showed that amylopectin from wheat grown at a lower temperature had a greater proportion of shorter chains. Amylopectin branch chains were classified into three groups based on the correlation coefficients between the data of branch chain length distribution and principal component scores, degree of polymerization (DP) of 6–12, DP 13–34, and DP ≥ 35. The gelatinization temperature of starches increased markedly at a higher matur...