ABSTRACT Free lipids (FL) in 72 hard winter wheat flours were extracted and dissolved in hexane. Absorbance (log 1/T) values were measured using a scanning spectrophotometer with a 2‐mm cuvette, and used to develop calibration models for estimating flour FL content and glycolipid (GL) and digalactosyldiglyceride (DGDG) contents. Fifty‐one calibration samples were selected based on the cutoff point of 0.3 of Mahalanobis distance, and the remaining twenty‐one samples were used for validation. The best model for the estimation of FL content showed coefficients of determination ( R 2 ) of 0.95 for the calibration set and R 2 = 0.89 for the validation set. Glycolipid contents could be estimated by a model which had R 2 = 0.87 for the calibration set and R 2 = 0.89 for the validation set. For DGDG, the best model showed R 2 = 0.94 for the calibration set and R 2 = 0.88 for the validation set.
Kernel vitreousness is an important grading characteristic for segregation of subclasses of hard red spring (HRS) wheat in the United States. This research investigated the protein molecular weight distribution (MWD) and the flour and baking quality characteristics of different HRS wheat market subclasses. The U.S. regional crop quality survey samples obtained from six regions for three consecutive growing years were used for subclass segregation based on the dark, hard, and vitreous (DHV) kernel percentage. Flour milled from HRS wheat with greater percentages of DHV kernel showed higher water absorption capacity for breadmaking. Protein MWD parameters could be related to the association between DHV kernel level and water absorption. Specifically, flour protein fractions rich in gliadins and high‐molecular‐weight polymeric proteins in the SDS‐unextractable fraction were identified to have significant and positive correlations with both DHV kernels and flour water absorption levels. An example further showed the importance of flour water absorption on potential economic incentives that can be gained with having a greater percentage of vitreous kernels. This information could help the flour milling and baking industry to segregate the different subclasses of HRS wheat with varying DHV content for their intended end‐use applications.
ABSTRACT This research was initiated to investigate associations between flour breadmaking traits and mixing and empirical dough rheological properties under thermal stress. Thirty hard spring wheat flour samples were analyzed by a Mixolab standard procedure. Mixolab profiles were divided into six different stages, and torque measurements of individual stages were modeled by nonlinear curve fitting using a compound of two solution searching procedures, multidimensional unconstrained nonlinear minimization and genetic algorithm. Mixing patterns followed exponential equations. Dough torque patterns under heat constraint, specifically dough thermal weakening and pasting profiles, were described by a sigmoid logistic equation as a function of time. Dough stability during heating appeared important for bread loaf volume increase from significant correlations between bread loaf volume and parameters generated from models of a dough thermal weakening stage. Multivariate continuum regression was employed to calibrate prediction models of baking traits using Mixolab parameters. Coefficients of determination estimated from prediction models and cross‐validation were greater than 0.98 for bake water absorption, mixing time, and bread loaf volume, indicating that the Mixolab parameters have a potential to enhance evaluation of flour breadmaking quality.
The objective of this study was to determine if the pre-harvest glyphosate application time affects the chemistry of wheat starch. Glyphosate was sprayed at the ripe stage (recommended) and the soft dough stage (early application) of hard red spring wheat. Wheat kernel samples were collected before application and every 3 days until harvest, after which different starch characteristics were analyzed. The results indicate that glyphosate timing does not impact the spatial distribution or morphology of starch granules, as well as the percentage or molecular weight of amylose and amylopectin. However, thermal characteristics of wheat starch, especially when glyphosate was applied at the soft dough stage, showed significant differences. A decrease in the average amylopectin chain length and differences in the proportion of short-, medium-, and long-chain amylopectin was also observed. Overall, this study shows that the pre-harvest application of glyphosate can affect wheat starch chemistry, especially if applied earlier than recommended. PRACTICAL APPLICATIONS: Glyphosate is the most commonly used herbicide in the world, and it is sometimes used pre-harvest during wheat cultivation. The recommended time of application is 7 days prior to harvest when the crops are in the ripe stage of physiological maturity. However, some crops may not be at this stage during application due to non-uniform maturation in the field. The goal of this work was to determine the effect of glyphosate application time (recommended/ripe stage vs. early/soft dough stage) on wheat starch chemistry. The results show that the starch chain length characteristics and thermal behavior are impacted, especially if applied early. Thus, this study shows the importance of timely application to avoid effects on starch chemical properties, which in return could impact starch functionality in food systems. This information is critical in the field of agriculture and to our knowledge this study is one of the first in this area.
This study was conducted to determine the effect of pre-harvest glyphosate application on spring wheat quality characteristics, ranging from kernel quality to baking quality. Two wheat cultivars were grown in three locations, and glyphosate was applied at the recommended rate at the soft dough stage (early application) and the ripe stage (recommended application time). When glyphosate was applied at the soft dough stage, kernel weight, wheat protein and wet gluten decreased significantly (p ≤ 0.05), however, gluten index significantly increased (p ≤ 0.05). Dough quality, farinograph stability, and quality number were significantly (p ≤ 0.05) higher when glyphosate was applied at the soft dough stage, and absorption and the mixing tolerance index were lower. As for baking quality, loaf volume and mix time were significantly (p ≤ 0.05) higher in the treated samples in comparison to the untreated control, and other baking quality characteristics did not show any significant difference. Overall, the results indicate that spring wheat quality characteristics are impacted to the greatest degree when glyphosate is applied earlier than recommended at the soft dough stage, as opposed to the recommended application at the ripe stage of physiological development.
ABSTRACT Dual‐purpose durum ( Triticum turgidum L. subsp. durum ) wheat, having both good pasta and breadmaking quality, would be an advantage in the market. In this study, we evaluated the effects of genotype and varying HMW and LMW glutenin subunit composition on durum breadmaking quality. Genotypes included five near‐isogenic backgrounds that also differed by variability at the Glu‐D1d (HMW subunits 1Dx5+1Dy10), Glu‐B1 (presence or absence of subunit 1By8), and Glu‐B3 (LMWI or LMWII pattern) loci. Quality tests were conducted on genotypes grown at five North Dakota locations. Genotype had a stronger influence on free asparagine content than glutenin subunit composition. Genotypes carrying Glu‐D1d had higher glutenin content than lines that did not carry Glu‐D1d . Among Rugby translocation genotypes, lines carrying LMWI had higher gliadin content and better loaf volume than genotypes carrying LMWII. Absence of 1By8 produced major reductions in loaf volume in nontranslocation lines regardless of whether LMWI or LMWII was present. In contrast, the presence of Glu‐D1d compensated well for the absence of 1By8 regardless of which LMW pattern was present. The durum genotypes did not have loaf volumes equal to bread wheat cultivars, and results suggest that improved extensibility is needed to improve durum breadmaking quality.
Abstract Background and objectives Experimental breadmaking is the ultimate test for wheat end‐use quality. This research objective was to investigate the consistency of different breadmaking methods in the evaluation of hard red spring (HRS) wheat. Sponge‐and‐dough method (SpDM) and straight‐dough method (StDM) were tested with varying loaf sizes and fermentation times. Findings For pound loaf breads, SpDM showed larger volume and higher stability among wheat samples than StDM. Correlation and biplot analyses revealed that 2‐hr fermentation was more consistent with pound SpDM than 3‐hr fermentation when flour samples were evaluated by micro‐ and pup loaf StDM. Mixograph, farinograph, extensograph, and solvent retention capacity tests were also evaluated for associations with breadmaking quality. Lactic acid solvent retention capacity had a higher correlation ( r = .86, p < .001) with mean breadmaking scores when compared with other parameters. Conclusions The findings of this study indicate that SpDM is more suited for commercial production of pound loaf, while StDM with 2‐hr fermentation is better for quality evaluation because of expediency and consistency in HRS wheat. Lactic acid solvent retention capacity is more adaptable than other flour parameters to predict breadmaking quality, especially when sample quantity is limited. Significance and novelty This research provides valuable insight that helps identify an experimental breadmaking procedure and a flour quality parameter useful for the evaluation of HRS wheat.
