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1.
The sodium hydroxide (NaOH) test for determining wheat color class depends on the observation that on soaking in NaOH, red wheat turns a darker red and white wheat turns straw yellow. To understand the mechanism of this test, Raman spectra of wheat bran, wheat starch, ferulic acid, and whole kernels of wheat, before and after NaOH soak, were studied. The major observable components in the whole kernel were that of starch, protein, and ferulic acid, perhaps esterified to arabinoxylan and sterols. When kernels are soaked in NaOH, spectral bands due to ferulic acid shift to lower energy and show a slightly reduced intensity that is consistent with deprotonation of the phenolic group and extraction of a portion of the ferulic acid into solution. Other phenolic acids, alkyl resorcinols, and flavonoids observed in the NaOH extracts of wheat by HPLC were not observed in the Raman spectra. Wheat bran accounts for most of the ferulic acid in the whole kernel, as indicated by the increased intensity of the doublet at 1,631 and 1,600 cm‐1 in the bran. The intense starch band at 480 cm‐1 in whole kernel wheat was nearly absent in the wheat bran.  相似文献   

2.
Red and white wheats must be segregated for marketing purposes because they have different end uses. Identification of wheat color is not straightforward, and currently there is interest in characterizing red and white wheats using spectroscopic methods and chemical tests. The kernels of both red and white wheats exhibit natural fluorescence that can be readily viewed under UV light, although it is not possible to differentiate the fluorescence spectra of red and white wheats by visual inspection only. Fluorescence emission spectra in the wavelength range of 370–670 nm for 91 wheat samples consisting of 48 red (from 30 cultivars) and 43 white (from 18 cultivars) were analyzed by partial least squares (PLS) and neural networks analyses (NNA). Samples included cultivars that were difficult to classify visually as well as wheat harvested after rainfall. Classification accuracies were ≈85% for calibration and ≈72% for the validation samples by both analyses. A plot of β‐coefficient vs. wavelength in PLS analysis indicated that fluorescence of red wheat cultivars was greater than that for white wheat cultivars at 425 (±20) nm wavelength. Fluorescence of white wheat cultivars was greater than that for red cultivars at 587 (±35) nm. Fluorescence emission at ≈450 nm from wheat samples increased in intensity after treatment with NaOH. The increase was greater for red than for white wheat. Wheat harvested after rainfall also exhibited a slight increase in fluorescence.  相似文献   

3.
A diode-array system, which measures spectral reflectance from 400 to 700 nm, was used to quantify single wheat kernel color before and after soaking in NaOH as a means of determining color class. Wheat color classification is currently a subjective determination and important in determining the end-use of the wheat. Soaking kernels in NaOH and classifying the soaked kernels with the diode-array system resulted in more difficult-to-classify kernels correctly classified (98.1%) than the visual method of classifying kernels (74.8%). Kernel orientation had a slight effect on correct classification, with the side view correctly classifying more kernels than the dorsal or crease view. The diode-array system provided a means of quantifying kernel color and eliminated inspector subjectivity when determining color class.  相似文献   

4.
Molecular markers for the red grain color (R) loci controlling seed color and the polyphenol oxidase (Ppo‐A1) locus controlling polyphenol oxidase (PPO) activity in seed have recently been developed. These markers provided the opportunity to convert the hard red spring wheat cultivars Choteau and Hank to white‐seeded versions with high and low PPO levels, respectively. These sets of near‐isogenic lines provided material to test the effects of seed color and PPO activity on a range of end‐use quality traits. We tested recurrent parents Choteau and Hank, along with near‐isogenic derivatives with white seed, in two replicated trials in Bozeman, Montana, for end‐use quality parameters. The white‐seeded lines consisted of both high‐ and low‐PPO near‐isogenic lines. The primary impact of white seed was the production of whole wheat bread with a perceived sweeter taste relative to the red‐seeded lines. Noodle color was not consistently impacted by the level of PPO variation despite relatively large reductions in PPO level. The alleles for white seed color did not appear to impact agronomic traits. These results suggested that hard white low‐PPO hard spring wheat would be advantageous in terms of conferring brighter color to Asian noodles and a sweeter taste to whole wheat bread.  相似文献   

5.
Short growing seasons and lack of water limit the number of crops that can be productively grown in the Northern Great Plains, but wheat is uniquely adapted to the region. Growers interested in diversification of their operations are growing more than one class of wheat to target different markets. This has led to the challenge of maintaining class purity, in that contamination with alternate classes results in lower prices to the farmer. The primary rationale is that mixtures may have poor end‐use quality. In these experiments, we tested hard red spring wheat and hard white spring wheat contaminated with different levels of soft white spring wheat, durum wheat, hull‐less barley, and the hard wheat of the alternate kernel color for milling and baking quality. Our results showed that contamination of hard red and hard white spring wheat with soft white wheat and hull‐less barley often influenced end‐use quality in that flour yield was negatively affected at relatively low levels. Loaf volume was normally only affected at higher levels. Durum wheat contamination caused fewer quality problems at generally higher levels of contamination. Contamination of hard red or hard white wheat by hard wheat of the alternate color class rarely affected quality, and effects were both positive and negative, depending on quality attributes of the pure samples. Growers wishing to diversify by growing both hard red and hard white wheat would benefit if buyers and end users were willing to accept higher levels of contamination for alternate classes that are unlikely to cause problems in eventual end use.  相似文献   

6.
Grain hardness (kernel texture) is of central importance in the quality and utilization of wheat (Triticum aestivum L.) grain. Two major classes, soft and hard, are delineated in commerce and in the Official U.S. Standards for Grain. However, measures of grain hardness are empirical and require reference materials for instrument standardization. For AACC Approved Methods employing near‐infrared reflectance (NIR) and the Single Kernel Characterization System (39‐70A and 55‐31, respectively), such reference materials were prepared by the U.S. Dept. of Agriculture Federal Grain Inspection Service. The material was comprised of genetically pure commercial grain lots of five soft and five hard wheat cultivars and was made available through the National Institute of Standards and Technology (SRM 8441, Wheat Hardness). However, since their establishment, the molecular‐genetic basis of wheat grain hardness has been shown to result from puroindoline a and b. Consequently, we sought to define the puroindoline genotype of these 10 wheat cultivars and more fully characterize their kernel texture through Particle Size Index (PSI, Method 55‐30) and Quadrumat flour milling. NIR, SKCS, and Quadrumat break flour yield grouped the hard and soft cultivars into discrete texture classes; PSI did not separate completely the two classes. Although all four of these methods of texture measurement were highly intercorrelated, each was variably influenced by some minor, secondary factors. Among the hard wheats, the two hard red spring wheat cultivars that possess the Pina‐D1b (a‐null) hardness allele were harder than the hard red winter wheat cultivars that possess the Pinb‐D1b allele based on NIR, PSI, and break flour yield. Among the soft wheat samples, SKCS grouped the Eastern soft red winter cultivars separate from the Western soft white. A more complete understanding of texture‐related properties of these and future wheat samples is vital to the use and calibration of kernel texture‐measuring instruments.  相似文献   

7.
The carotenoid concentration of durum wheat is a criterion for the assessment of semolina quality, and it is of particular importance in determining the color of pasta. Thus, the development of a rapid screening method for kernel and semolina color has facilitated increasing the yellow color in durum wheat cultivars. However, the distribution of the pigment might vary within the ear of the wheat. The micromethod for the determination of yellow pigment concentration (YPC) of single wheat kernels now allows the discovery of whether this variation is the same for cultivars with different carotenoid concentrations. All of the cultivars investigated showed similar trends in the arrangements of the kernels within the ears, with the central positions of the ears being the most stable for YPC. Indeed, the best combination of higher YPC and larger kernel size is seen for the basal‐central region of the ear, which can be used for the selection during wheat‐breeding programs of cultivars with a more intense yellow color.  相似文献   

8.
Polyphenol oxidase (PPO) causes Asian noodles to lose their bright color over time. Null Ppo‐A1 and Ppo‐D1 alleles are available that confer very low kernel PPO levels. Our goal was to characterize the effect of the Ppo‐A1i and Ppo‐D1f null alleles on the color and texture profile of white salted noodles. A white‐seeded spring wheat carrying Ppo‐A1i/Ppo‐A2d and Ppo‐D1f was crossed to a hard white‐seeded isoline of Choteau spring wheat with Ppo‐A1b/Ppo‐A2a and Ppo‐D1b and to a hard white‐seeded isoline of Vida spring wheat with Ppo‐A1a/Ppo‐A2b and Ppo‐D1b. Resultant lines homozygous for the null‐Ppo alleles or for the alternate parent Ppo alleles were selected and grown in replicated trials. The null‐Ppo alleles had no detrimental effects on kernel or flour traits. Noodles prepared from straight‐grade or whole wheat flour from the null‐Ppo allele class were less cohesive and softer than noodles from the alternate parent Ppo allele class for the White Choteau but not the White Vida population. Noodles prepared from straight‐grade and whole wheat flour from the null‐Ppo class were brighter, more red, and more yellow after 24 h and showed less change in L* with time than noodles prepared from the alternate parent Ppo class. The relative difference between the two genotype classes for change in L* with time (0–24 h) exceeded 3.5 L* for noodles from both types of flour, which was an improvement over existing low‐Ppo alleles. Incorporating the null‐Ppo alleles into wheat varieties could improve the color profile of Asian noodles.  相似文献   

9.
An automated single kernel near‐infrared system was used to select kernels to enhance the end‐use quality of hard red wheat breeder samples. Twenty breeding populations and advanced lines were sorted for hardness index, protein content, and kernel color. To determine whether the phenotypic sorting was based upon genetic or environmental differences, the progeny of the unsorted control and sorted samples were planted at two locations two years later to determine whether differences in the sorted samples were transmitted to the progeny (e.g., based on genetic differences). The average hardness index of the harvested wheat samples for segregating populations improved significantly by seven hardness units. For the advanced lines, hardness index was not affected by sorting, indicating little genetic variation within these lines. When sorting by protein content, a significant increase from 12.1 to 12.6% was observed at one location. Purity of the red samples was improved from ≈78% (unsorted control) to ≈92% (sorted samples), while the purity of the white samples improved from 22% (control) to ≈62% (sorted samples). Similar positive results were found for sorting red and blue kernel samples. Sorting for kernel hardness, color, and protein content is effective and based upon genetic variation.  相似文献   

10.
A comprehensive analysis of the variation in wheat grain ash content has not been previously conducted. This study assessed the relative contribution of genotype and environment to variation in ash content, with a particular aim of ascertaining the potential for manipulating the trait using contemporary adapted germplasm. A total of 2,240 samples were drawn from four years of multilocation field plots grown in the wheat production areas of Oregon and Washington states. Genotypes included commercial cultivars and advanced breeding lines of soft and hard winter, and soft and hard spring wheats with red and white kernel color, several soft white club wheats, and one soft white spring waxy wheat cultivar. In addition to ash, protein content, test weight, and Single Kernel Characterization System kernel hardness, weight and size were also measured. In total, 20 separate fully balanced ANOVA results were conducted. Whole model R2 values were highly significant, 0.62–0.91. Nineteen of the 20 ANOVA results indicated significant genotype effects, but the effects were not large. In contrast, environment effects were always highly significant with F values often one to two orders of magnitude larger than the genotype F values. The grand mean for all samples was 1.368% ash. For individual data sets, genotype means across environments varied ≈0.1–0.3% ash. The genotypes judged noteworthy because they had the highest least squares mean ash content were OR9900553 and ClearFirst soft white winter, NuHills hard red winter, Waxy‐Pen and Cataldo soft white spring, and WA8010 and Lochsa hard spring wheats. Genotypes with lowest least squares mean ash were Edwin (club) soft white winter, OR2040073H hard red winter, WA7952 soft white spring, and WA8038 hard spring wheats. In conclusion, wheat grain ash is more greatly influenced by crop year and location than by genotype. However, sufficient genotype variation is present to plausibly manipulate this grain trait through traditional plant breeding.  相似文献   

11.
Two wheat cultivars, soft white winter wheat Yang‐mai 11 and hard white winter wheat Zheng‐mai 9023, were fractionated by kernel thickness into five sections; the fractionated wheat grains in the 2.7–3.0 mm section were separated sequentially into three fractions according to kernel specific density. Physical properties of unfractionated, fractionated, and separated wheat grains and the physicochemical properties of processed wheat flour were determined. Test weight, relative density, and whiteness of flour in the middle kernel thicknesses were maximal and those properties decreased with increasing or decreasing kernel thickness; they also decreased with decreasing kernel specific density. Extensigraph properties showed the same results. Water absorption of flour and kernel hardness increased with increasing kernel thickness and decreasing kernel specific density. The farinograph properties also were related to kernel thickness and specific density. Pasting viscosity increased with increasing kernel thickness for sections from <2.5 mm to 3.0–3.2 mm, except that the >3.2 mm section was lowest; the kernels with the lightest specific density also were lowest. Thus, the quality of wheat grains with the greatest kernel thickness was not the best, and in fact may be the worst. The quality of wheat grains with small kernel thickness and light kernel specific density generally were worst. Most physicochemical properties of unfractionated and unseparated wheat grains were accurately predicted by the weighted‐average of the different kernel thickness sections and different kernel specific density fractions, except relative density, falling number, dough development time, and pasting temperature.  相似文献   

12.
The solvent retention capacity test (SRC) (AACC Approved Method 56‐11) of flour is used to evaluate multiple aspects of wheat (Triticum aestivum L.) quality including pentosan content, starch damage, gluten strength, and general water retention based on the ability of flour to retain a range of solvents. The objectives of this study were to evaluate the effects of grain production environment in general and crop irrigation and fertility management in particular on SRC of soft wheat flour, and to evaluate the ability of SRC to predict end‐use quality across diverse environments. Two soft white spring wheat cultivars ‘Pomerelle’ and ‘Centennial’ were produced in a range of irrigated and rain‐fed production environments. SRC profiles and milling and baking quality parameters were measured. In a two‐year study at Aberdeen, ID, with two late‐season irrigation management regimes and two crop nitrogen fertility treatments, only wheat genotype significantly affected flour SRC. In two‐year studies at Tetonia, ID, one conducted under rain‐fed conditions and the other under irrigation, additional fertilizer applied at anthesis did not affect SRC. Correlations among quality parameters were determined using the Aberdeen and Tetonia flour samples, as well as samples of the same genotypes grown in fertility trials under rain‐fed conditions at Havre and Bozeman, MT, and under irrigation at Bozeman. Patterns of correlations among SRC values were similar for both genotypes. Grain test weight was negatively correlated with sodium carbonate and sucrose SRC of both genotypes. Flour protein was strongly positively correlated with sucrose and lactic acid SRC of both genotypes. The optimal regression models for predicting sugar snap cookie diameter (AACC Approved Method 10‐52) as a function of protein, SRC, flour extraction, and kernel hardness were different for the two cultivars. SRC evaluations of flours from these trials were consistent with large genotype and environment effects, yet minimal genotype × environment interaction. This suggests that selection among genotypes within an environment will produce a gain‐from‐selection observable in multiple and diverse environments.  相似文献   

13.
An optical radiation measurement system, which measured reflectance spectra, log (1/R), from 400 to 2,000 nm, was used to quantify single wheat kernel color. Six classes of wheat samples were used for this study, including red wheat that appears white and white wheat that appears red. Partial least squares regression and multiple linear regression were used to develop classification models with three wavelength regions, 500–750, 500–1,700, and 750–1,900 nm, and three data pretreatments, log (1/R), first derivative, and second derivative. For partial least squares models, the highest classification accuracy was 98.5% with the wavelength region of 500–1,700 nm. The log (1/R) and the first derivative yielded higher classification accuracy than the second derivative. For multiple linear regression models, the highest classification accuracy was 98.1% obtained from log (1/R) spectra from the visible and near-infrared wavelength regions.  相似文献   

14.
The concentration of ferulic acid (FA), the major phenolic acid in the wheat kernel, was found to differ significantly in the mature grain of six wheat cultivars known to have a range of tolerance to the orange wheat blossom midge (Sitodiplosis mosellana). Differences in FA content were correlated with floret infestation level of the cultivars. The wheat cultivars ranked similarly in FA content at the four locations where they were tested, despite a significant effect of environment. Ferulic acid was synthesized mainly during the early stages of grain filling but at different rates among cultivars. Ferulic acid was concentrated primarily in the shorts and bran fractions in an insoluble-bound form. A high correlation was obtained between FA contents as determined by GLC, fluorometry, UV, and colorimetry. The colorimetric procedure was modified as a qualitative, simple, and rapid test for identifying midge-resistant wheat and evaluated in several field trials. The method should provide a rapid tool in the preliminary screening of experimental lines in the development of midge-resistant wheat cultivars.  相似文献   

15.
Worldwide, nearly 20 times more common wheat (Triticum aestivum) is produced than durum wheat (T. turgidum subsp. durum). Durum wheat is predominately milled into coarse semolina owing to the extreme hardness of the kernels. Semolina, lacking the versatility of traditional flour, is used primarily in the production of pasta. The puroindoline genes, responsible for kernel softness in wheat, have been introduced into durum via homoeologous recombination. The objective of this study was to determine what impact the introgression of the puroindoline genes, and subsequent expression of the soft kernel phenotype, had on the milling properties and flour characteristics of durum wheat. Three grain lots of Soft Svevo and one of Soft Alzada, two soft‐kernel back‐cross derived durum varieties, were milled into flour on the modified Quadrumat Senior laboratory mill at 13, 14, and 16% temper levels. Samples of Svevo (a durum wheat and recurrent parent of Soft Svevo), Xerpha (a soft white winter wheat), and Expresso (a hard red spring wheat) were included as comparisons. Soft Svevo and Soft Alzada exhibited dramatically lower single‐kernel characterization system kernel hardness than the other samples. Soft Svevo and Soft Alzada had high break flour yields, similar to the common wheat samples, especially the soft hexaploid wheat, and markedly greater than the durum samples. Overall, Soft Svevo and Soft Alzada exhibited milling properties and flour quality comparable, if not superior, to those of common wheat.  相似文献   

16.
Wheat product quality is related to its physicochemical properties and to the viscoelastic properties of the kernel. The aim of this work was to evaluate the viscoelastic properties of individual wheat kernels using the uniaxial compression test under small strain (3%) to create experimental conditions that allow the use of the elasticity theory to explain the wheat kernel viscoelasticity and its relationships to physicochemical characteristics, such as weight tests, size, and ash and protein contents. The following viscoelastic properties of the kernels of hard and soft wheat cultivars at two different moisture contents (original and tempered at 15%) were evaluated: total work (Wt), elastic work (We), plastic work (Wp), and modulus of elasticity (E). There was a significant decrease in Wt as the moisture content increased. In the soft wheat Saturno, Wt decreased 80% (from 0.217 to 0.044 N·mm) as the moisture content increased. Individual wheat kernels at their original moisture content showed higher We than under the tempered condition. Wp increased as the moisture content increased. E decreased as the moisture content increased. The soft wheat Saturno showed the highest decline (54.9%) in E (from 14.18 to 6.39 MPa) as the moisture content increased. There were significant negative relationships between the viscoelastic properties and the 1,000‐kernel weight and kernel thickness. The uniaxial compression test under small strain can be applied to evaluate the viscoelastic properties of individual wheat kernels from different classes and cultivars.  相似文献   

17.
A simple, highly efficient and reproducible two‐step extraction procedure using dilute acetic acid without (AN) and then with sonication (AS) has been developed for the fractionation of wheat flour protein. Approximately 97% of total protein was extracted from a Canadian hard red spring wheat flour; an additional 1.2% protein could be recovered by further extraction with 1% DDT and 50% 1‐propanol (AR). Size‐exclusion HPLC (SE‐HPLC) and flow field‐flow fractionation (flow FFF) showed that the AN extract, which accounted for most of the total extractable protein (AN + AS + AR), consisted primarily of monomeric protein. The AS extract was composed primarily of polymeric proteins. Flow FFF showed that AN polymeric protein, including that eluting at the SE‐HPLC void volume, showed smaller Stokes diameters than AS polymeric protein. Flow FFF profiles of AS SE‐HPLC subfractions showed that the void volume subfraction contained monomeric and small polymeric protein in addition to large polymeric protein, indicating formation of larger complexes through interaction between some or all of the components. AN and AS extracts, as well as SE‐HPLC and flow FFF fractions thereof, showed a fairly wide range of values among 12 Canadian hard red and white spring wheat cultivars. The proportion of total protein in the AS extract and in the larger sized polymeric protein fractions from SE‐HPLC and flow FFF were highly positively correlated to farinograph mixing time.  相似文献   

18.
An automated single kernel near‐infrared (NIR) sorting system was used to separate single wheat (Triticum aestivum L.) kernels with amylose‐free (waxy) starch from reduced‐amylose (partial waxy) or wild‐type wheat kernels. Waxy kernels of hexaploid wheat are null for the granule‐bound starch synthase alleles at all three Wx gene loci; partial waxy kernels have at least one null and one functional allele. Wild‐type kernels have three functional alleles. Our results demonstrate that automated single kernel NIR technology can be used to select waxy kernels from segregating breeding lines or to purify advanced breeding lines for the low‐amylose kernel trait. Calibrations based on either amylose content or the waxy trait performed similarly. Also, a calibration developed using the amylose content of waxy, partial waxy, and wild‐type durum (T. turgidum L. var durum) wheat enabled adequate sorting for hard red winter and hard red spring wheat with no modifications. Regression coefficients indicated that absorption by starch in the NIR region contributed to the classification models. Single kernel NIR technology offers significant benefits to breeding programs that are developing wheat with amylose‐free starches.  相似文献   

19.
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.  相似文献   

20.
Wheat breeders need a nondestructive method to rapidly sort high‐ or low‐protein single kernels from samples for their breeding programs. For this reason, a commercial color sorter equipped with near‐infrared filters was evaluated for its potential to sort high‐ and low‐protein single wheat kernels. Hard red winter and hard white wheat cultivars with protein content >12.5% (classed as high‐protein, 12% moisture basis) or < 11.5% (classed as low‐protein) were blended in proportions of 50:50 and 95:5 (or 5:95) mass. These wheat blends were sorted using five passes that removed 10% of the mass for each pass. The bulk protein content of accepted kernels (accepts) and rejected kernels (rejects) were measured for each pass. For 50:50 blends, the protein in the first‐pass rejects changed as much as 1%. For the accepts, each pass changed the protein content of accepts by ≈0.1%, depending on wheat blends. At most, two re‐sorts of accepts would be required to move 95:5 blends in the direction of the dominant protein content. The 95:5 and 50:50 blends approximate the low‐ and high‐protein mixture range of early generation wheat populations, and thus the sorter has potential to aid breeders in purifying samples for developing high‐ or low‐protein wheat. Results indicate that sorting was partly driven by color and vitreousness differences between high‐ and low‐protein fractions. Development of a new background specific for high‐ or low‐protein and fabrication of better optical filters for protein might help improve the sorter performance.  相似文献   

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