Pan Bread and Chinese White Salted Noodle Qualities of Chinese Winter Wheat Cultivars and Their Relationship with Gluten Protein Fractions

Improvement of food processing quality has become a major breeding objective in China. Nineteen Chinese leading winter wheat cultivars with improved quality and two Australian cultivars with high bread and noodle-making qualities were sown in four locations for two years to investigate dough properties, pan bread, and Chinese white salted noodle (CWSN) qualities, and their association with the quantity of protein fractions. The results indicated that genotype, environment, and genotype-by-environment interaction significantly affected most of quality traits and amount of protein fractions. Genotype mainly determined the quantity of gluten protein fractions and pan bread quality parameters, while environment was the most important source of variation for the noodle quality parameters. Chinese cultivars were characterized by acceptable protein content (11.1–13.4%), medium to strong dough strength (maximum resistance 176.9–746.5 BU), medium to poor dough extensibility (166.5–216.4 mm), fair to very good pan bread qualities, and good to very good CWSN qualities. Gliadin contributed more in quantity to protein content (r = 0.80, P < 0.001), however, glutenin and its subgroups were more important to dough strength. The quantity of glutenin, HMW-GS, and LMW-GS were highly and significantly correlated with dough strength-related traits such as farinograph development time, stability, extensigraph maximum resistance, and extension area (r = 0.70–0.91, 0.65–0.89, and 0.70–0.91, respectively; P < 0.001). The quantity of LMW-GS could explain 82.8% of the total variation of dough maximum resistance. The quantity of gliadin and the ratio of HMW-GS to LMW-GS determined dough extensibility (r = 0.75 and r = –0.59, respectively; P < 0.001 and P < 0.01, respectively). Higher quantity of glutenin and lower ratio of gliadin to glutenin resulted in higher bread score with r = 0.70 (P < 0.001) and r = –0.74 (P < 0.001), respectively. However, protein content and its fractions have a moderate undesirable effect on CWSN parameters such as color, firmness, and taste. Therefore, both allelic variation and quantity of storage protein fractions should be considered in breeding cultivars with improved pan bread making quality.     

Survey of White Salted Noodle Quality Characteristics in Wheat Landraces

The introduction of novel quality characteristics from wheat (Triticum aestivum L.) landraces can enhance the genetic diversity of current wheat breeding programs. The composition of starch and protein in wheat is important when determining the end‐product quality, particularly for white salted noodles (WSN). Quality characteristics that contribute to the production of improved WSN include high starch pasting peak viscosity, low amylose content, high proportion of A‐type granules, low protein content, soft grain texture, and high protein quality as measured by SDS sedimentation volume. A survey of 133 wheat landraces from Afghanistan, China, Egypt, Ethiopia, India, Iran, Syria, and Turkey was conducted to examine the genetic variability of starch and protein quality characteristics. Two wheat cultivars, Rosella and Meering, were used as the quality controls. The variation in starch pasting peak viscosities observed among the wheat landraces had a range of 175–295 Rapid Visco Analyser units (RVU), where 52 of the landraces were not significantly different from Rosella, a commercial soft grain wheat with high pasting properties. The amylose content of the landrace population was 23.4–30.2%, where 17 landraces had significantly lower values than Rosella. The proportion of A‐type granules was 60.5–73.9%, where 112 landraces had significantly higher values than Rosella. The grain texture hardness score was 28.0–99.3, the total protein content was 8.0–15.1%, and the adjusted SDS sedimentation volume (SDS/protein) was 1.6–7.0 mL/%P. The landrace AUS4635 had high starch pasting peak viscosity, high breakdown, low amylose content, low protein content, soft grain texture, and high protein quality flour. This wheat is an ideal parent to use in a breeding program that increases the genetic variation available to develop cultivars with high‐quality WSN characteristics.     

Effects of Protein Content and Composition on White Noodle Making Quality: Color

Wheat cultivars, representing three winter and three spring wheats were grown in western Canada with six levels of nitrogen fertilizer and flours were prepared from them with an extraction rate of 65%. Using a chromameter, flour color and the color of uncooked white noodle sheets made from these flours with different resting times were assessed. The cooked noodle sheet color was also assessed. While protein content initially declined with added nitrogen and increased with further nitrogen addition, brightness (L*) of flour decreased and redness (a*) and yellowness (b*) increased. Positive correlation coefficients of flour brightness with particle size index (PSI) were also observed. Flour redness (a*) and yellowness (b*) were also affected by flour moisture content, whereas L* values were not significantly correlated with moisture contents. For the uncooked white noodle sheet, as protein content increased brightness decreased but there was an increase in a* and b* values. Thus, the L* value for noodle sheets was negatively correlated with the a* and b* values. The percentages of monomeric protein and soluble glutenin in flour were equal to or better than protein content in relation to most noodle sheet color characters. Uncooked noodle sheet brightness decreased, while redness and yellowness increased with rest time. In general, uncooked white noodle sheets prepared from different wheat flours can be ranked in terms of brightness and yellowness within each level of nitrogen fertilization.     

Relationship Between Physicochemical Properties of Starches and White Salted Noodle Quality in Japanese Wheat Flours

This study describes the effect of starch properties of Japanese wheat flours on the quality of white salted noodles (WSN). Starch was isolated from 24 flours of 17 Japanese cultivars and amylose content was determined along with pasting properties by Rapid Visco Analyser (RVA), thermal properties by differential scanning calorimetry (DSC), and the distribution of amylopectin chain length by high‐performance anion exchange chromatography (HPAEC). Twenty flours were used to prepare WSN. As expected, 5–6% lower amylose content was associated with good WSN quality (higher scores in softness, elasticity, and smoothness). RVA analysis indicated that the pasting temperature had the greatest influence on WSN quality, while breakdown and setback showed slight effects on WSN quality. DSC results showed that lower endothermal enthalpy (ΔH) in the amylose‐lipid complex was associated with good WSN quality. Chainlength distribution of amylopectin by HPAEC was not an important factor in relation to WSN quality.     

我国部分冬小麦新品种（系）SSR标记遗传差异的研究

本研究利用53对SSR引物对全田1999－2000年北方冬麦区及黄淮冬麦区观察圃中选出的48个新品种（系）进行遗传差异研究，共检测出58个SSR位点上的367个等位变异，平均每个位点有6.33个等位变异，其中B组每个位点的等位变异最多，这表明B基因组化更快，分化更大。48个品种（系）在全基因组及A、B、D基因组聚类结果表明这些品种的相似系数聚类的范围较小，为0.75－0.98。全基因组聚类结果与品种的系谱来源及育成地区相吻合。研究结果表明我国冬小麦品种的种质基础相对较狭窄。加强不同来源种质的利用和特异亲本类型的培育对我国冬小麦遗传改良非常重要，利用5个多态性高的SSR标记就可以将这48个小麦新品种（系）区分开，每个品种（系）都有各自独特的指纹图谱。     

Variation in Polyphenol Oxidase Activity and Quality Characteristics Among Hard White Wheat and Hard Red Winter Wheat Samples

Polyphenol oxidase (PPO) has been related to an undesirable brown discoloration of wheat-based end products. Consumer acceptance and product quality are generally decreased by the darkening phenomena. Two sets of wheat samples (Triticum aestivum L.) were investigated for variation in grain and flour PPO levels. Samples included 40 advanced experimental hard white winter wheat lines grown at two Kansas locations and 10 hard red winter wheat genotypes grown at three Nebraska locations. The variability in grain and flour PPO activities was influenced by growing location and population for the hard white wheat samples. There also was a significant influence of population by growing location interactions on PPO activity in both grain and flour. Genotype and growing location both contributed to variability in flour PPO activity among the hard red wheat samples. The variation in flour PPO activities among growing locations appeared larger than variation produced by genotypes tested for the hard red wheat samples. Quality parameters, such as wheat physical properties, flour protein and ash contents, grain color, and milling yield significantly correlated with grain and flour PPO activities. Among red wheat samples, flour PPO activity was related to 100 kernel weight, first reduction flour yield, and flour ash content. Grain PPO activity was related to variation in grain color observed among hard white samples. The relationship of quality characteristics with grain and flour PPO activities varied among white and red wheat samples.     

22个冬小麦品种主要农艺和品质性状遗传多样性分析

为了解甘肃天水地区育成冬小麦品种的遗传多样性,提高种质资源的利用效率,以22份冬小麦品种为试验材料,研究了其主要农艺性状与品质性状的变异情况、遗传多样性指数,并进行了主成分分析和聚类分析。结果表明,农艺性状中,穗粒数的变异系数最大(11.5%),千粒重的遗传多样性指数最高(1.75);品质性状中,沉降值的变异系数最大(31.3%),容重的遗传多样性指数最高(1.87)。说明供试材料的遗传多样性较丰富。8个性状的主成分分析结果表明,前4个主成分的累计贡献率为82.636%,用类平均法(UPGMA)将22个品种聚为5类,其中第Ⅰ类群可作为提高品质的材料供育种选择,第Ⅴ类群可作为增产材料供育种选择。     

Reduced Amylose Effects on Bread and White Salted Noodle Quality

Amylose content in wheat endosperm is controlled by three Wx loci, and the proportion of amylose decreases with successive accumulation of Wx null alleles at the three loci. The proportion of amylose is believed to influence end‐use quality of bread and Asian noodles. The objectives of this study were to determine influence of the allelic difference at Wx‐B1 locus on bread quality, bread firmness, and white salted noodle texture in a spring wheat cross segregating for the Wx‐B1 locus and in a set of advanced spring wheat breeding lines differing in allelic state at the Wx‐ B1 locus. In addition, we examined the relationship between amylose content and flour swelling properties on bread and noodle traits. Fifty‐four recombinant inbred lines of hard white spring wheat plus parents were grown in replicated trials in two years, and 31 cultivars and breeding lines of hard spring wheat were grown in two locations. Bread and white salted noodles were processed from these trials. The presence of the Wx‐B1 null allele reduced amylose content by 2.4% in a recombinant inbred population and 4.3% in a survey of advanced breeding lines and cultivars compared with the normal. The reduced amylose was accompanied by an average increase in flour swelling power (FSP) for the Wx‐B1 null group of 0.8 g/g for the cross progeny and 2.3 g/g for the cultivar survey group. The Wx‐B1 allelic difference did not affect flour protein in cross progeny where the allelic difference was not confounded with genetic background. Bread from the Wx‐B1 null groups on average had increased loaf volume and was softer than the normal group for the cross progeny and cultivar survey group. The Wx‐B1 allelic difference altered white salted noodle texture, most notably noodle springiness and cohesiveness where the Wx‐B1 null groups was more springy and more cohesive than the normal groups for both sets of genetic materials. Flour protein was more highly related to loaf volume than were FSP or amylose. Both flour protein and FSP were positively related to noodle textural traits, but especially noodle springiness and cohesiveness.     

Endoxylanase Inhibition Activity in Different European Wheat Cultivars and Milling Fractions

Twenty‐three wheat samples from 19 different European wheat cultivars (Triticum aestivum L.) were tested for their quantitative and qualitative variation in inhibition activity against family 11 endoxylanases of Aspergillus niger, Bacillus subtilis, and Trichoderma viride and a family 10 endoxylanase of A. aculeatus. Under the experimental conditions, the A. aculeatus enzyme was not inhibited by the wheat extracts, the A. niger and B. subtilis endoxylanases were affected to a similar extent, while the T. viride enzyme was much more inhibited. The inhibition activities in the different wheat samples against the A. niger, B. subtilis, and T. viride endoxylanases varied between 36.0 and 11.7, 34.0 and 12.9, and 86.2 and 46.6 IU/100 mg of dry whole meal, respectively. One IU (inhibition unit) corresponds to the amount of inhibitor resulting in 50% inhibition of endoxylanase activity under the conditions of the assay. The inhibitor activities were linearly related, indicating that the levels of different endoxylanase inhibitors with different endoxylanase specificities in the dormant wheat grains are also linearly related or that one (or more) of these inhibitors are predominantly present or has much higher specific activity, consequently causing almost all of the inhibition activity measured. Wheat flour accounted for ≈57% of the total inhibition activity in wheat grains, while the shorts and bran fractions each contained ≈21% of the total activity. On dry weight basis, the inhibition activities were about three times higher in shorts and about two times higher in bran than in flour. The results obtained may be useful in explaining differences in functionality of different endoxylanases in biotechnological processes in which wheats of different cultivars, or fractions thereof, are used as well as in screening endoxylanases for applications in wheat‐based processes.     

Genotypic and Environmental Modification of Asian Noodle Quality of Hard Winter Wheats

The relative effects of environment, genotype, and their interactions on the modification of Asian noodle quality attributes were assessed using 38 winter wheat (Triticum aestivum L.) cultivars and breeding lines grown in replicated trials at three Nebraska locations in harvest year 2000. Noodle color was determined in both white salted and yellow alkaline procedures, and noodle textural features were investigated by producing white salted noodles. Significant environmental, genotypic, and genotype‐by‐environment variation was observed for nearly all initial and 24‐hr noodle color traits in both types of noodles. Significant genotypic effects were observed for several textural traits, while significant environmental effects were observed only for noodle hardness and water uptake. However, among the noodle textural traits, the genotype‐by‐environment interaction was significant only for noodle firmness. High and significant phenotypic correlations were observed between color traits in the two noodle applications. Genetic correlations were of lower magnitude, indicating the possibility of breeding wheats specifically for various noodle color types. Strong negative phenotypic and genetic correlations were observed between flour protein content and noodle brightness (L*) values in both yellow alkaline and white‐salted applications. Textural traits largely were independent of noodle color traits. When significant phenotypic or genetic correlations were observed between variable pairs, invariably similar correlations were observed with flour protein content. Noodle cutting force, cutting area, and final thickness showed strong phenotypic and genetic correlations with each other and with protein content. These variables largely were independent of noodle firmness and hardness, which were, in turn, more dependent on alleles at the wheat wx‐A1 and wx‐B1 (waxy) loci. Noodle firmness was greatest in flours from wild‐type wheats; lines with a null allele only at the wx‐A1 locus did not differ from wild‐type. Softest noodles were produced from lines carrying null alleles at both wx‐A1 and wx‐B1, while lines with a null only at wx‐B1 were intermediate in softness.     

山东省冬小麦品种冠层结构及光截获的研究

研究了山东省14个冬小麦高产品种（系）的冠层结构和光截获（LI）及分布特性。结果表明：参试材料间盛花期冠层消光系数K存在显著差异。中下层叶片相对光强（I／I0）的差异程度大于上层叶片。适度的增加上部节间长、提高株高构成指数（IL）、降低上层叶片面积所占比例和角度指数，有助于减小冠层K并改善透光条件。盛花期LI及分布特性对作物生长率（CGR）、籽粒形成及最终产量有重要影响。并对小麦冠层结构改良和研究的有关问题进行了探讨。     

Relationship Between Protein Characteristics and Instant Noodle Making Quality of Wheat Flour

We investigated the relationship between the protein content and quality of wheat flours and characteristics of noodle dough and instant noodles using 14 hard and soft wheat flours with various protein contents and three commercial flours for making noodles. Protein content of wheat flours exhibited negative relationships with the optimum water absorption of noodle dough and lightness (L*) of the instant noodle dough sheet. Protein quality, as determined by SDS sedimentation volume and proportion of alcohol‐ and salt‐soluble protein of flour, also influenced optimum water absorption and yellow‐blueness (b*) of the noodle dough sheet. Wheat flours with high protein content (>13.6%) produced instant noodles with lower fat absorption, higher L*, lower b*, and firmer and more elastic texture than wheat flours with low protein content (<12.2%). L* and free lipid content of instant noodles were >76.8 and <20.8% in hard wheat flours of high SDS sedimentation volume (>36 mL) and low proportion of salt‐soluble protein (<12.5%), and <75.7 and >21.5% in soft wheat flours with low SDS sedimentation volume (<35 mL) and a high proportion of salt‐soluble protein (>15.0%). L* of instant noodles positively correlated with SDS sedimentation volume and negatively correlated with proportion of alcohol‐ and salt‐soluble protein of flour. These protein quality parameters also exhibited a significant relationship with b* of instant noodles. SDS sedimentation volume and proportion of salt‐soluble protein of flours also exhibited a significant relationship with free lipid content of instant noodles (P < 0.01 and P < 0.001, respectively). Protein quality parameters of wheat flour, as well as protein content, showed significant relationship with texture properties of cooked instant noodles.     

Characteristics and Protein Subunit Composition of Flour Mill Streams from Different Commercial Wheat Classes and Their Relationship to White Salted Noodle Quality

Proximate characteristics and protein compositions of selected commercial flour streams of three Australian and two U.S. wheats were investigated to evaluate their effects on the quality of white salted noodles. Wheat proteins of flour mill streams were fractionated into salt‐soluble proteins, sodium dodecyl sulfate (SDS)‐soluble proteins, and SDS‐insoluble proteins with a sequential extraction procedure. SDS‐soluble proteins treated by sonication were subsequently separated by nonreducing SDS polyacrylamide gel electrophoresis (SDS‐PAGE). There was a substantial amount of variation in distributions of protein content and protein composition between break and reduction mill streams. SDS‐insoluble proteins related strongly to differences in protein quantity and quality of flour mill streams. The soluble protein extracted by SDS buffer included smaller glutenin aggregates (SDS‐soluble glutenin) and monomeric proteins, mainly gliadin (α‐, β‐, γ‐, and ω‐types) and albumin and globulin. SDS‐soluble proteins of different flour mill streams had similar protein subunit composition but different proportions of the protein subunit groups. Noodle brightness (L) decreased and redness (a) increased with increased SDS‐insoluble protein and decreased monomeric gliadin. Noodle cooking loss and cooking weight gain decreased with increased glutenin aggregate (SDS‐soluble glutenin and SDS‐insoluble glutenin) and decreased monomeric gliadin. Noodle hardness, springiness, cohesiveness, gumminess, chewiness, tensile strength, breaking length, and area under the tensile strength versus breaking length curve increased with increased glutenin aggregate. Monomeric gliadin contributed differently to texture qualities of cooked noodles from glutenin aggregate. Monomeric albumin and globulin were not related to noodle color attributes (except redness), noodle cooking quality, and texture qualities of cooked noodles. The results suggested that variation in protein composition of flour mill streams was strongly associated with noodle qualities.     

Effect of Amaranthus and Buckwheat Proteins on Wheat Dough Properties and Noodle Quality

Isoelectric protein concentrates (IPC) were prepared from one buckwheat (Fagopyrum esculentum) and five Amaranthus genotypes. Their effect on the mixing properties of a wheat flour was studied. Mixograph and dynamic oscillatory measurements showed significant increases in dough strength with the addition of 2 and 4% IPC, correlated to the water-insoluble fraction level of the IPC. The same IPCs were used at 2% level to supplement a wheat flour in making Chinese dry noodles. Measurable changes in both the raw and cooked noodle color were observed, and the change caused by addition of buckwheat IPC was substantial. Some of the IPCs caused an increase in cooking loss and only one caused an increase in weight, while increase in volume of the cooked noodles was not significantly affected. The changes in the rheological properties of cooked noodles due to addition of IPCs were measured. Overall, their effects were favorable, but the changes were statistically significant in only a few cases. The substantial dough-strengthening effect of the IPCs was hence not effectively translated into improved cooked noodle quality, and possible reasons for this are discussed.     

Effects of Flour Extraction Rate,Added Water,and Salt on Color and Texture of Chinese White Noodles

Both cultivar and noodle composition and preparation have important effects on noodle quality. In this study, the effects of flour extraction rate (50, 60, and 70%), added water (33, 35, and 37%), and salt concentration (0, 1, and 2%, w/w) on color and texture of Chinese white noodle (CWN) were investigated using flour samples from five leading Chinese wheat cultivars. The five samples showed large variations in protein content, ash content, flour color, farinograph, and extensigraph parameters, and starch pasting properties. Analyses of variance indicated that cultivar, flour extraction rate, level of water addition, salt concentration, and the interactions had significant effects on color of raw noodle sheets and color and textural properties of CWN. Cultivar and water addition were more important sources of variation than flour extraction rate and salt concentration. The brightness (L*) and redness (a*) values of raw noodle sheets were significantly reduced and increased, respectively, as flour extraction rate increased from 50 to 70%, and noodle scores were slightly higher at flour extraction rates of 50%. Water addition showed different effects on raw noodle sheet color at 2 and 24 hr, and a significant improvement was observed for noodle appearance, firmness, viscoelasticity, smoothness, and total score as water addition increased from 33 to 37%. L* of raw noodle sheets, and firmness and viscoelasticity of cooked noodles, were significantly improved, but noodle flavor significantly deteriorated as salt concentration increased from 0 to 2%; 1% salt produced the highest noodle score. Thus, the recommended composition for laboratory preparation of CWN is 60% flour extraction, 35% water addition, and 1% salt concentration.     

Quality Response of Twelve Hard Red Winter Wheat Cultivars to Foliar Disease Across Four Locations in Central Kansas

Twelve hard red winter wheat cultivars were grown at four locations in central Kansas to evaluate the role of foliar fungal diseases on wheat end-use quality in 1995. Disease was allowed to develop naturally on control plots and was controlled partially on plots treated with a systemic fungicide. After harvest, wheat samples were evaluated for the impact of the disease complex (leaf rust, tan spot, speckled leaf blotch) on physical grain quality, grain protein, milling properties, flour absorption, and peak mixing time. Data were analyzed using a mixed model to account for random (location and block) and fixed (cultivar and fungicide) effects. Location significantly influenced quality characteristics except kernel size and peak mixing time. The magnitudes of variation among random effects on all quality characteristics were larger for location than for the interactions between location × cultivar and location × fungicide. The fixed effects portion of the analysis revealed that the cultivar × fungicide treatment interaction significantly affected test weight, kernel protein, and flour absorption. Fungicide treatment resulted in significant increases in yield and kernel weight. Cultivar significantly affected all quality characteristics except kernel size and peak mixing time. Disease resistance exerted a significant influence on yield and test weight. The economic benefit associated with improved wheat quality from fungicide treatment was variety specific. Three cultivars (TAM 107, Karl 92, and Ike), which account for 50% of the 1997 planted wheat acres in Kansas, demonstrated positive improvements in test weight and protein in response to fungicide treatment.     

Responese of Two Cultivars of Winter Wheat Differing In Sensitivity to Aluminum Toxicity

A experiment was carried to evaluate the effects of Al on growth,accumulations of free proline and amino acid in 2 wheat cultivars(Triticum aestivum L.),Yangmai No.5 and Jian 864,differing in Al Sensitivity.Plants grew initially in a nutrient solution without Al for 13 days before the addition of Al and finally in a nutrient solution containing 0.5mmol Al(L^-1)for 19 days,the results showed that there were marked deceases in dry weight,relative growth rate(RGR) and net assimilation rate (NAR)of Al-treated seedlings compared with control plants.The Al effects were more evident in Yangmai No.5 than Jian 864.Leaf area ratio(LAR) was little affected by Al.RGR was highly correlated with NAR rather than LAR.Aluminum increased the concentrations of free proline and total free amino acid in shoots of both the cultivars.The increases were greater in Yangmai No.5 than in Jian 864.The percentage of free proline in total amino acid in shoots was not affected by Al treatment.It was possible that accumulation of proline was merely a symptom of Al injury.The concentrations of total nitrogen in Al-treated plants did not significantly differ from those of control plants.Nitrate reductase activity(NRA),in leaves was severely decreased by Al,and a greater decrease was noted in Yangmai No.5 than in Jian 864,but NRA in roots of both the cultivars was not affected.The decreases in NRA might be and indirect(accumulation of amino acid) rather than a direct result of Al toxicity.     

Impacts of SSIIa‐A Null Allele on Durum Wheat Noodle Quality

A small increase in amylose content may impact end‐product quality of wheat. The effect of elevated amylose content in durum wheat is not known. We surveyed 255 durum wheat accessions and found two genotypes that lacked the SGP‐A1 protein. These genotypes were crossed to Mountrail, an adapted durum genotype, to create populations segregating for the SSIIa‐Ab null allele. Our goal was to determine the influence of allelic variation at the SSIIa‐A locus on semolina properties and end‐product quality with noodles as a test product. Amylose content increased 3% and cooked noodle firmness increased 2.8 g·cm for the SSIIa‐Ab class compared with the SSIIa‐Aa class for the PI 330546 source, but no change in either trait was detected between classes for the IG 86304 source. The SSIIa‐Ab class had a 10% reduction in flour swelling compared with the SSIIa‐Aa class for both crosses. Grain protein and semolina yield did not differ between SSIIa‐A classes. The relationship between flour swelling power and noodle firmness did not differ between SSIIa‐A allelic classes within a cross. The different results for amylose content and noodle firmness between these sources may be because the two sources of the SSIIa‐Ab null mutation contributed different linkages to the segregating populations. Results show that the SSIIa‐Ab allele could be used to produce durum‐based products that are slightly more firm in texture. However, the effect of the SSIIa‐Ab allele may depend on the source.     

Baking Quality of Bread Wheat Cultivars Damaged by Nysius simulans

Wheat grain may be attacked by different insect species. Among them, some Heteroptera species (e.g., Aelia spp. and Eurygaster spp.) reduce wheat breadmaking quality; others, such as Nysius simulans , commonly extract water and nutrients from soy plants. The aim of this study was to assess the effect of N. simulans infestation on breadmaking quality of different bread wheat cultivars. Twelve wheat cultivars (damaged and undamaged by N. simulans ) were studied. Infested grain percentage varied between 51 and 78%, depending on cultivar. Protein and gluten quantity and quality were significantly reduced in damaged flours, as shown by gluten index, solvent retention capacity, and SDS sedimentation index. SDS‐PAGE from water‐extractable proteins evidenced an important proteolytic activity in damaged samples. Dough rheological properties showed a reduced dough viscoelasticity in damaged samples. Microbread specific volume changed from 3.26 cm³/g for samples made with undamaged flour to 2.77 cm³/g for bread made with damaged flour. No evidence for modification in starch properties was found. The infestation by N. simulans reduced wheat breadmaking quality in all cultivars studied, as a result of proteolytic activity occurring after dough hydration. Results suggest that the presence of N. simulans should be considered as a factor affecting wheat crops, mainly those located next to soy crop areas, which is the usual host for this insect.     

Single-Kernel Characteristics of Hard Winter Wheats in Relation to Milling and Baking Quality

To investigate relationships of wheat single kernel (SK) characteristics with end-use properties, we used 12 hard winter wheat cultivars harvested at six regions in Kansas in 1993. Significant positive correlations occurred among wheat hardness parameters including near-infrared reflectance hardness score, SK hardness index (SK-HI), and SK peak force (SK-PF) obtained by the Single Kernel Characterization System (SKCS). The SKCS characteristics also were significantly correlated to conventional wheat quality parameters such as test weight, kernel density, and kernel sizing. Flour yields were significantly correlated with SK-PF, SK-HI, and SK weight (SK-WT), suggesting the usefulness of SKCS in evaluating milling quality. The negative correlation of milling score with the standard deviation of SK-HI and SK-PF indicated that uniformity of SK hardness is desirable for good milling performance. However, bread loaf volumes had significant negative correlations with SK diameter and SK-WT, mainly due to the inverse relationship between wheat protein contents and kernel weights or sizes. Loaf volume regression values, the changes in loaf volumes per one percentage point of flour protein, also had significant negative correlations with SK-HI, SK-PF, and SK-WT.