Evaluation of wheat and emmer varieties for artisanal baking,pasta making,and sensory quality

Identifying varieties best suited to local food systems requires a comprehensive understanding of varietal performance from field to fork. After conducting four years of field trials to test which varieties of ancient, heritage, and modern wheat grow best on organically managed land, we screened a subset of varieties for bread, pastry, pasta, and cooked grain quality. The varieties evaluated were three lines of emmer (T. turgidum L. ssp. dicoccum Schrank ex Schübl) and eleven lines of common wheat (Triticum aestivum L.), including two modern soft wheat varieties, four soft heritage wheat varieties, four hard modern wheat varieties, and one hard heritage wheat variety. A diverse group of bakers, chefs, researchers, and consumers compared varieties for qualities of interest to regional markets. Participants assessed differences in sensory profiles, pasta making ability, and baking quality for sourdough, matzah crackers, yeast bread, and shortbread cookies. In addition to detecting significant differences among varieties for pasta, sourdough, and pastry quality, participants documented variation in texture and flavor for the evaluated products. By demonstrating which varieties perform best in the field, in the bakery, and on our taste buds, these results can support recommendations that strengthen the revival of local grain economies.     

中国糯小麦品种的主要农艺性状和品质性状分析

为明确中国生产上糯小麦品种的主要性状及其演化规律,以2005-2022年已经审定的44个糯小麦品种为材料,对其主要农艺性状和品质性状进行了分析评价。结果表明：(1)春性品种和冬性品种的生育期变异系数分别为19.75%和4.03%,其余四个被测性状变异系数从大到小依次为产量、穗粒数、千粒重、株高,产量的变异系数均大于20%。(2)春性品种和冬性品种4个品质性状的变异系数均表现为湿面筋含量>粗蛋白含量>容重>支链淀粉含量,除紫糯麦1号外,其余糯小麦品种的支链淀粉含量均≥97%。(3)通过聚类分析,将44个糯小麦品种分为3大类,Ⅰ类包含28个品种,占总数的64%,产量和品质中等;Ⅱ类包含11个品种,占总数的25%,具有较高产量和品质;Ⅲ类含5个品种,占总数的11%,产量和品质偏低。     

Effect of temperature variation during grain filling on wheat gluten resistance

The objective was to investigate effects of natural variation in temperature during grain filling on wheat (Triticum aestivum L) gluten quality. Seventeen field trials with four different varieties were conducted during the years 2005–2008. Temperature records were obtained from automatic weather stations located near the field trial sites. The period from heading to yellow ripeness was divided into 20 sub-phases of equal thermal time units, and a last sub-phase comprising the seven days after yellow ripeness. Partial Least Squares Regression was used to relate the temperature records of the different sub-phases to gluten quality analysed by the Kieffer Extensibility test and the SDS sedimentation test.     

Endogenous arabinoxylans variability in refined wheat flour and its relationship with quality traits

Arabinoxylans (AXs) are the major dietary fiber (DF) component in wheat and their consumption has been associated with several health benefits. Genetic improvement of the AX in refined wheat flour could be a good solution to improve the DF daily consumption while maintaining the flour desirable quality. In this study, 193 common wheat lines were analyzed for their AX content in refined flour and end-use quality. Wide variation in both the total arabinoxylan (TOT-AX) (10.8–16.5 mg/g) and water-extractable arabinoxylan (WE-AX) (3.2–7.6 mg/g) was identified and, in both cases, the genotype had the greatest impact on the observed phenotypes. Variation in the endogenous AX fractions appeared to have a moderate effect on wheat quality. The WE-AX, specifically, were positively correlated with gluten strength (r = 0.11 to 0.32) and bread loaf volume (r = 0.16), whereas the TOT-AX were negatively correlated with dough extensibility (r = −0.11) and bread making quality (r = −0.11). Overall, results of this study show that the genetic improvement of grain AX is feasible and that the AXs present in refined flour do not dramatically alter wheat quality indicating that it is possible to select varieties with high AX endosperm content end desired end-use quality.     

基于高光谱图像技术的小麦种子分类识别研究

为了探讨高光谱图像技术在小麦种子分类识别中应用的可行性,采集了河南地区主要种植的7个小麦品种的种子高光谱图像及900～1 700nm范围的光谱信息,建立了主成分分析法(PCA)-支持向量机(SVM)分类模型。运用PCA对光谱数据进行降维处理,结合SVM模型比较了不同实验条件下小麦种子分类准确率以及在最佳条件下3个、4个和6个品种种子的分类准确率。结果显示,3个品种间种子分类准确率除个别外平均达到95%以上,4个品种间种子分类准确率在80%左右,6个品种间种子分类准确率在66%左右。这说明充分利用光谱信息可以对3个或4个小麦品种进行多籽粒分类。     

Study of the microstructure of durum wheat endosperm using X-ray micro-computed tomography

Durum wheat grains are used for producing food, such as pasta or couscous. The grain mechanical properties which are linked to its internal micro-structure (i.e. endosperm porosity) are known to determine its ability to produce semolina during milling. The proportion of grains having porous endosperm in a batch appears therefore as a critical quality factor for the durum wheat value chain. Our objective was to investigate the ability of X-ray micro-tomography (μCT) method to describe the porous or vitreous counterpart structures in the endosperm of durum wheat grains. We selected two different durum wheat samples displaying vitreous or partially porous endosperms. The grains were analyzed using μCT at two pixel sizes (1 μm or 7 μm). The μCT data collected at 7 μm pixel size were used for qualitative classification of grains according to apparent distribution curve of the porosity parameters. Analysis of μCT images at 1 μm pixel size allowed us to propose pore size classification in the vitreous and porous parts of the endosperm in three durum wheat grain. Results are used to better describe the durum-wheat endosperm microstructure, but requires long scanning periods.     

Grain yield increase in cereal variety mixtures: A meta-analysis of field trials

Plant ecology theory predicts that growing seed mixtures of varieties (variety mixtures) may increase grain yields compared to the average of component varieties in pure stands. Published results from field trials of cereal variety mixtures demonstrate, however, both positive and negative effects on grain yield. To investigate the prevalence and preconditions for positive mixing effects, reported grain yields of variety mixtures and pure variety stands were obtained from previously published variety trials, converted into relative mixing effects and combined using meta-analysis. Furthermore, available information on varieties, mixtures and growing conditions was used as independent variables in a series of meta-regressions. Twenty-six published studies, examining a total of 246 instances of variety mixtures of wheat (Triticum aestivum L.) and barley (Hordeum vulgare L.), were identified as meeting the criteria for inclusion in the meta-analysis; on the other hand, nearly 200 studies were discarded. The accepted studies reported results on both winter and spring types of each crop species. Relative mixing effects ranged from −30% to 100% with an overall meta-estimate of at least 2.7% (p < 0.001), reconfirming the potential of overall grain yield increase when growing varieties in mixtures. The mixing effect varied between crop types, with largest and significant effects for winter wheat and spring barley. The meta-regression demonstrated that mixing effect increased significantly with (1) diversity in reported grain yields, (2) diversity in disease resistance, and (3) diversity in weed suppressiveness, all among component varieties. Relative mixing effect was also found to increase significantly with the effective number of component varieties. The effects of the latter two differed significantly between crop types. All analyzed models had large unexplained variation between mixing effects, indicating that the variables retrievable from the published studies explained only a minority of the differences among mixtures and trials.     

Effects of variety and fertiliser nitrogen on alcohol yield, grain yield, starch and protein content, and protein composition of winter wheat

The effects of nitrogen (N) fertiliser on grain size and shape, starch and protein concentration, vitreosity, storage protein composition, and alcohol yield of two winter wheat varieties contrasting in endosperm texture were studied in a field trial in Herefordshire, UK in 2004. Averaged across varieties, the alcohol yield was 439 L/tonne for grain with a protein concentration of 11.5 g/100 g. The soft endosperm wheat variety Riband produced on average 7.7 L more alcohol per tonne of grain at a given protein concentration than the hard endosperm variety, Option. At the same time, N fertiliser was shown to have significant effects on alcohol production through its major influence on grain protein concentration. Averaged over both varieties, there was a reduction in alcohol yield of 5.7 L for each 10 kg increase in protein content per tonne of grain. The starch concentration of Riband was 2.9 g/100 g higher than Option at a given grain protein concentration, supporting its higher observed alcohol yields. A low conversion of starch to alcohol in this study (6.30 L/10 kg starch) compared to the theoretical value (6.61 L/10 kg starch) indicated that there is potential for improvement of this character. The traits relating to grain size and shape were principally influenced by genotype, and were not influenced by N fertiliser. Conversely, there were only minor genotypic effects on grain protein concentration and vitreosity. An important finding was that there were no interactions between variety and N treatment for any of the variables considered, indicating that the response of the two varieties to changes in applied N was the same, resulting in consistent differences in starch concentration and alcohol yield between genotypes at different levels of grain protein. An analysis of the composition of the wheat storage proteins by size-exclusion chromatography showed that the gliadins increased on average by 0.56 g per g increase in total grain protein and were quantitatively the major protein fraction, suggesting that selection for low gliadin content may be a desirable means by which to reduce grain protein, and thereby increase alcohol yield in wheat. The relationship between alcohol yield per unit area and applied N rate was described by a quadratic function and the maximum alcohol yield per unit area was ca. 3630 L/ha. Statistical analysis suggested that the economic optimum rate of N applied for grain yield was close to the optimum N rate for maximum alcohol productivity.     

The impact of emmer genetic diversity on grain protein content and test weight of hexaploid wheat under high temperature stress

High temperature has a negative impact on wheat grain quality and reduces market value. Emmer wheat (Triticum dicoccon Schrank), one of the earliest domesticated wheat species, is a source of genetic diversity for the improvement of heat and drought tolerance in modern wheat. However, the potential of emmer wheat for the improvement of grain physical quality under high temperature stress is little studied. A diverse set of 184 emmer-based hexaploid lines was developed by crossing emmer wheat with hexaploid wheat and backcrossing once to hexaploid wheat. These materials, seven hexaploid recurrent parents and seven commercial cultivars, were evaluated at two times of sowing (E1 and E2) in the field, in 2015–2016. The materials were genotyped using a 90 K SNP platform and these data were used to estimate the contribution of emmer wheat to the progeny. Significant phenotypic and genetic variation for grain physical quality traits including protein content and test weight was observed. High temperature significantly increased protein content and decreased test weight. Large scale field phenotyping identified emmer progenies with improved grain characteristic compared to their respective parents and commercial cultivars in both environments. A few families consistently produced higher trait means across environments compared to their recurrent parents. The emmer wheat parent contributed between 1 and 37% of the genome in emmer-based genotypes. Selected emmer derived lines with superior protein content and test weight, tended to have a greater genetic contribution from the emmer parent, ranging from 12 to 37% and 7–37% in E1 and E2, respectively. It was concluded that new genetic variation for seed traits, such as protein content and test weight, can be introduced to hexaploid wheat from emmer wheat. The newly developed emmer derivatives identified with enhanced grain quality under high temperature stress can potentially be used to improve grain quality through breeding.     

The effect of tillage practice,input level and environment on the grain yield of winter wheat in the Czech Republic

The response of winter wheat grain yield to four variants of treatment (two input levels, combined with either conventional or reduced tillage) was tested over six seasons at three locations. These experiments with 10 and 12 winter wheat varieties were analysed within three experimental series. The environmental (location and season) effects on grain yield were large in all combinations of input level and tillage type, and the varieties responded differentially to both season and location. However, there was no varietal response either to the tillage system used, or to the level of nitrogen (and other inputs) supplied. The high input reduced tillage system (surface stubble-ploughing to a depth of 8–10 cm) resulted in all series in significantly higher grain yields than the equivalent conventional tillage system. The reduced tillage system combined with high input level delivered a yield advantage for all of the wheat varieties tested.     

The effect of ridge planting and earliness of durum wheat varieties on sunn pest (Eurygaster spp.) damage and grain yield

Sunn pests (Eurygaster spp.) are among the most important insect pests of wheat (Triticum sativum L.) and barley (Hordeum vulgare L.). Cultural practices can prevent or minimize common sunn pest (Eurygaster integriceps Puton) population densities and crop damage. A three-year field experiment (Jun 05 to Aug 07) was conducted in Diyarbakır in the southeast Antolia region of Turkey, to evaluate the effects of planting method (no-till ridge planting and conventional planting) and earliness of durum wheat (Triticum durum L.) varieties (early, mid-season and late varieties) on E. integriceps density, grain damage and overall grain yield. The effect of the planting method on the sunn pest density and percent of grains damaged by sunn pest was not significant; however, there was a significant difference among the different varieties used in this study. While Çeşit-1252 (late wheat variety) had the highest nymph density (11.2 nymphs m⁻²) and percent of sunn pest damaged grains (2.8%), Sarıçanak-98 (early wheat variety) had the lowest nymph density (4.3 nymphs m⁻²) and percent of sunn pest damaged grains (0.8%). Grain yield was the highest (5.99 t ha⁻¹) for Sarıçanak-98 while there was no significant difference between Aydın-93 (5.06 t ha⁻¹) and Çeşit-1252 (4.99 t ha⁻¹). In conclusion, this study suggests that planting methods may not have a significant effect on sunn pest density, percent of sunn pest damaged grains or grain yield; however, the use of early durum wheat varieties, such asSarıçanak-98, may reduce sunn pest population densities, percent of damaged grains, allowing increases in grain yield in southeast Anatolia region, Turkey.     

Proteomic analysis of the mature kernel aleurone layer in common and durum wheat

The aleurone layer (AL) is one of inner tissues removed from the grain with the wheat bran. It is the main source of vitamins, minerals and antioxidants of potential nutritional value in the wheat kernel. The AL of three varieties of each of the two main species of wheat, Triticum aestivum (ABD) and Triticum durum (AB), were manually dissected and analysed using two-dimensional gel-based proteomics. A total of 1258 and 1109 Coomassie-stained spots were detected in the AL of representatives of the ABD and AB genomes. In two varieties (T. aestivum Chinese Spring and T. durum Bidi17), grown in two different years with full fungicide protection, no quantitative or qualitative (presence/absence) differences in spots were detected, suggesting that AL proteome is strongly genetically controlled. Comparison within and between species revealed a total of 339 AL significant protein spots. Among these spots, 30.8% differed within T. aestivum and 56.5% within T. durum varieties, whereas only 12.7% differed between the two species. Among the 142 AL proteins identified using MALDI-TOF and LC-MS/MS, 57% were globulin type storage proteins (Glo-3, Glo-3B, Glo-3C, Glo-2), 16.2% were involved in carbohydrate metabolism and 17.6% in defence/stress pathways. These variations in AL proteome are discussed.     

Wheat grain quality under increasing atmospheric CO2 concentrations in a semi-arid cropping system

We investigated wheat (Triticum aestivum) grain quality under Free Air CO₂ Enrichment (FACE) of 550 ± 10% CO₂ μmol mol⁻¹. In each of two full growing seasons (2008 and 2009), two times of sowing were compared, with late sowing designed to mimic high temperature during grain filling. Grain samples were subjected to a range of physical, nutritional and rheological quality assessments. Elevated CO₂ increased thousand grain weight (8%) and grain diameter (5%). Flour protein concentration was reduced by 11% at e[CO₂], with the highest reduction being observed at the late time of sowing in 2009, (15%). Most of the grain mineral concentrations decreased under e[CO₂] - Ca (11%), Mg (7%), P (11%) and S (7%), Fe (10%), Zn (17%), Na (19%), while total uptake of these nutrients per unit ground area increased. Rheological properties of the flour were altered by e[CO₂] and bread volume reduced by 7%. Phytate concentration in grains tended to decrease (17%) at e[CO₂] while grain fructan concentration remained unchanged. The data suggest that rising atmospheric [CO₂] will reduce the nutritional and rheological quality of wheat grain, but at high temperature, e[CO₂] effects may be moderated. Reduced phytate concentrations at e[CO₂] may improve bioavailability of Fe and Zn in wheat grain.     

Wheat grain quality under increasing atmospheric CO2 concentrations in a semi-arid cropping system

We investigated wheat (Triticum aestivum) grain quality under Free Air CO₂ Enrichment (FACE) of 550 ± 10% CO₂ μmol mol⁻¹. In each of two full growing seasons (2008 and 2009), two times of sowing were compared, with late sowing designed to mimic high temperature during grain filling. Grain samples were subjected to a range of physical, nutritional and rheological quality assessments. Elevated CO₂ increased thousand grain weight (8%) and grain diameter (5%). Flour protein concentration was reduced by 11% at e[CO₂], with the highest reduction being observed at the late time of sowing in 2009, (15%). Most of the grain mineral concentrations decreased under e[CO₂] - Ca (11%), Mg (7%), P (11%) and S (7%), Fe (10%), Zn (17%), Na (19%), while total uptake of these nutrients per unit ground area increased. Rheological properties of the flour were altered by e[CO₂] and bread volume reduced by 7%. Phytate concentration in grains tended to decrease (17%) at e[CO₂] while grain fructan concentration remained unchanged. The data suggest that rising atmospheric [CO₂] will reduce the nutritional and rheological quality of wheat grain, but at high temperature, e[CO₂] effects may be moderated. Reduced phytate concentrations at e[CO₂] may improve bioavailability of Fe and Zn in wheat grain.     

Heat and drought stress on durum wheat: Responses of genotypes,yield, and quality parameters

Heat and/or drought stress during cultivation are likely to affect the processing quality of durum wheat (Triticum turgidum L. ssp. durum). This work examined the effects of drought and heat stress conditions on grain yield and quality parameters of nine durum wheat varieties, grown during two years (2008–09 and 2009–10). Generally, G and E showed main effects on all the parameters whereas the effects of G × E were relatively small. More precipitation in Y09–10 may account for the large differences in parameters observed between crop cycles (Y08–09 and Y09–10). Combined results of the two crop cycles showed that flour protein content (FP) and SDS sedimentation volume (SDSS) increased under both stress conditions, but not significantly. In contrast the gluten strength-related parameters lactic acid retention capacity (LARC) and mixograph peak time (MPT) increased and decreased significantly under drought and heat stress, respectively. Drought and heat stress drastically reduced grain yield (Y) but significantly enhanced flour yellowness (FY). LARC and the swelling index of glutenin (SIG) could be alternative tests to screen for gluten strength. Genotypes and qualtiy parameters performed differently to drought and heat stress, which justifies screening durum wheat for both yield and quality traits under these two abiotic stress conditions.     

Intra-specific variation of wheat grain quality in response to elevated [CO2] at two sowing times under rain-fed and irrigation treatments

In order to investigate the intra-specific variation of wheat grain quality response to elevated atmospheric CO₂ concentration (e[CO₂]), eight wheat (Triticum aestivum L.)cultivars were grown at two CO₂ concentrations ([CO₂]) (current atmospheric, 389 CO₂ μmol mol⁻¹vs. e[CO₂], FACE (Free-Air CO₂ Enrichment), 550  ±  10% CO₂ μmol mol⁻¹), at two water levels (rain-fed vs. irrigated) and at two times of sowing (TOS₁, vs. TOS₂). The TOS treatment was mainly imposed to understand whether e[CO₂] could modify the effects of timing of higher grain filling temperatures on grain quality. When plants were grown at TOS₁, TKW (thousand kernel weight), grain test weight, hardness index, P, Ca, Na and phytate were not significantly changed under e[CO₂]. On the other hand, e[CO₂] increased TKW (16%), hardness index (9%), kernel diameter (6%), test weight (2%) but decreased grain protein (10%) and grain phytate (11%) at TOS₂. In regard to grain Zn, Mn and Cu concentrations and some flour rheological properties, cultivar specific responses to e[CO₂] were observed at both sowing times. Observed genetic variability in response to e[CO₂] in terms of grain minerals and flour rheological properties could be easily incorporated into future wheat breeding programs to enable adaptation to climate change.     

Evaluating cultivars in unbalanced on-farm participatory trials

Data from on-farm participatory varietal trials are often highly unbalanced. Using statistically robust techniques we showed that such data are amenable to sophisticated analyses. Data from 38 varieties of wheat tested in 44 mother trials (all test varieties compared) and 663 baby trials (single entries compared with local checks) over 6 years in Lunawada, Gujarat, India, were analysed. Two combined analyses for grain yield were performed by using either a fixed effects model within general linear modelling (GLM) or a mixed effects model using the restricted maximum likelihood (REML) procedure. Both analyses made substantial adjustments over the raw means and the estimated mean values from the two analyses for the fixed set of tested varieties were highly correlated (R² = 0.89) as were the t-value that compared test cultivars with the check variety (R² = 0.96). The GLM detected 15 varieties and REML detected 12 varieties that were significantly superior to the check cultivar with 11 varieties in common. Both methods were similar in identifying the top-most promising varieties but REML was more conservative (i.e. more subject to Type II error) with larger standard errors (S.E.s) of variety means for n > 17. However, for both procedures the S.E.s increased sharply when the number of trials decreased below 17.     

Relationship between specific weight of spring barley and malt quality

The assessment of malting barley to determine if it meets grain quality requirements is an integral step in ensuring an efficient malting process and a good quality malt output. Specific weight (SW) is an industry standard criterion, however links between SW and malting are not well understood. In this study the effect of a changing SW on malting was investigated. Samples were manipulated according to both grain size and weight, creating grain fractions with a range in SW. Prior to malting, grain quality traits were measured, and after malting, malt quality traits were examined. Increased SW resulted in a reduced number of whole, unmodified corns in malt, implying increased levels of modification. Specific weight correlated with both hot water malt extract (r = 0.82, P < 0.01) and predicted spirit yield (r = 0.84, P < 0.01), this highlights an increased malt output. Furthermore peak gelatinisation temperature of extracted starch from the malt correlated with both SW (r = 0.69, P < 0.05) and grain density (r = 0.65, P < 0.05). This could benefit malt efficiency by increased conversion of starch to fermentable sugars, but with the same energy input. The changes in SW and consequently malt output in this study are a result of changing grain density rather than packing efficiency.     

A major QTL for gluten strength in durum wheat (Triticum turgidum L. var. durum)

Gluten strength is an important characteristic, determining the end product quality of durum wheat semolina. To identify the genetic basis of gluten strength in North Dakota durum cultivars, a doubled haploid population was developed from the cross of a weak gluten cultivar ‘Rugby’ and a strong gluten cultivar ‘Maier’. A framework linkage map consisting of 228 markers was constructed and used with phenotypic data on gluten strength (measured by sedimentation volume) to conduct single- and two-locus QTL analyses. Only one consistent QTL (QGs.ndsu-1B) contributing up to 90% of the phenotypic or 93% of the genotypic variation was detected on 1BS. No QTL × QTL or QTL × environment interactions were observed. The QGs.ndsu-1B was flanked by two DArT markers which were converted to STS markers and used along with SSR and EST-SSRs to develop a map of 1BS. QTL analysis delineated QGs.ndsu-1B in a 7.3 cM region flanked by an STS marker (STS-wPt2395) and a SSR marker (wmc85). The adapted background of this material and availability of PCR-based markers closely associated with this locus represent invaluable resources for marker-assisted introgression of gluten strength into other durum wheat varieties. A single QTL segregating in this population also makes it an ideal target for map-based cloning.     

Rheological and textural properties of tef [Eragrostis tef (Zucc.) Trotter] grain flour gels

Interest in tef [Eragrostis tef (Zucc.)Trotter] grain in food applications has increased in recent years because of its nutritional merits and the absence of gluten. With the objective of evaluating the suitability of tef for making gel type food products, gel viscoelastic properties of three varieties of tef (one brown and two white) at different concentrations (6, 8, 10, 12 & 14% w/w) were evaluated at 25 °C and 90 °C. The texture and color evolution for 16% (w/w) gels were evaluated. Proximate compositions of the flours were quantified. Rice, refined and whole wheat flours were analyzed as reference. The minimum flour concentration required for gel formation from the three tef varieties was 6–8%, similar to wheat flour. All tef flour suspensions pre-heated to 95 °C led to gels with a solid-like behavior (G′ > G″), both at 25 °C and 90 °C, with higher consistency than wheat gels at the same concentration. The dependence of viscoelastic moduli with concentration fulfilled the power law. The Avrami model was successfully fitted to the textural evolution of tef gels. Important differences were observed among tef and rice and wheat flours, probably contributed by their differences in protein, starch, lipid and fiber constituents. Gelling properties characterized suggest that tef flours would be suitable ingredients in gel food formulations.