A Modified Extensigraph Method for Evaluating Dough Properties of Hard Wheat Breeding Lines

A modified extensigraph method reduced sample quantity to 100 g from 300 g and testing time by half with easy dough preparation compared to the AACC standard extensigraph method, which challenges wheat breeding programs where the sample size is small and evaluations of large numbers of samples are demanded. Correlation coefficients (r) for 93 pairs of each of six extensigraph dough characteristics of 31 different tested wheat samples were r = 0.95 for resistance‐to‐extension, r = 0.80 for extensibility, r = 0.93 for ratio of resistance‐to‐extension to extensibility, r = 0.92 for ratio of maximum resistance‐to‐extension to extensibility, and r = 0.81 for area under the curve (energy). Correlation coefficients for the measurements of extensigraph dough characteristics at each of three rest‐time tests between the modified and standard methods were significant. Some dough mixing characteristics and bake tests correlated better with dough extension characteristics when determined by the modified method. Repeatability of the modified method test was good. The modified extensigraph method can be a useful alternative to the standard method for the milling and baking industries, crop quality surveys, and wheat quality research.     

Evaluation of a New Viscometer Performance in Predicting the Technological Quality of Soft Wheat Flour

Gluten aggregation properties were investigated by means of the GlutoPeak device, a viscometer recently proposed as a rapid and sensitive test for measurement of wheat flour technological performance. In this study, 62 soft wheat flour samples of different quality and end use were utilized to evaluate if the GlutoPeak parameters could adequately predict chemical and rheological characteristics of soft wheat flour dough, that is, protein content measured by the Kjeldahl method, dough strength measured by a Chopin alveograph, and dough stability and water absorption measured by a Brabender farinograph. Linear correlation analysis showed that most GlutoPeak curve parameters were strongly correlated with protein content, dough strength, and water absorption. The statistical models, obtained by a stepwise multiple regression method, showed the GlutoPeak device to be a promising tool to characterize wheat flour (R_adj² = 0.84 for protein content, R_adj² = 0.71 for dough strength, and R_adj² = 0.67 for water absorption). The rather high accuracy of the prediction models for the three mentioned parameters confirmed that GlutoPeak parameters are well correlated with other frequently used flour quality parameters and are able to describe flour technological performance.     

Generation of a Mixolab Profile After the Evaluation of the Functionality of Different Commercial Wheat Flours for Hot‐Press Tortilla Production

Refined wheat flours commercially produced by five different U.S. and Mexican wheat blends intended for tortilla production were tested for quality and then processed into tortillas through the hot‐press forming procedure. Tortilla‐making qualities of the flour samples were evaluated during dough handling, hot pressing, baking, and the first five days on the shelf at room temperature. The predominant variables that affected the flour tortilla performance were wet gluten content, alveograph W (220–303) and P/L (0.70–0.94) parameters, farinograph water absorption (57%) and stability (10.8–18.7 min), starch damage (5.43–6.71%), and size distribution curves (uniform particle distribution). Flours produced from a blend of Dark Northern Spring (80%) and Mexican Rayon (20%) wheat had the highest water absorption, and tortillas obtained from this blend showed the highest diameter and lowest thickness. The whitest and best textured tortillas were obtained from the flour milled from three hard types of Mexican wheat blend. A Mixolab profile was generated from the best tortilla flours, those produced by mills 3 and 4. The Mixolab profile showed that a good flour for hot‐press tortillas had a relatively lower absorption and short dough mix time compared with a bread flour and should have a significantly higher gluten compared with an all‐purpose flour. Compared with bread flour, the tortilla flour had higher retrogradation and viscosity values. The Mixolab profile proved to be a good preliminary test to evaluate flours for hot‐press tortillas.     

Effect of Wheat Genotype and Environment on Relationships Between Dough Extensibility and Breadmaking Quality

Dough extensibility affects processing ease, gas retention, and loaf volume of finished products. The Kieffer dough extensibility test was developed to assess extensibility of small dough samples and is therefore adapted for use in breeding programs. Information is lacking on relationships between wheat growing environments and dough properties measured by the Kieffer dough extensibility test. This study documents the variability of dough extensibility (Ext), maximum resistance to extension (Rmax), and area under the extensibility curve (Area) in relation to breadmaking quality, and the effect of wheat growing environments. Mixograph, Kieffer dough extensibility, and bake tests were performed on flour milled from 19 hard red spring wheat (Triticum aestivum L.) genotypes grown during three growing seasons (2007‐2009) at six South Dakota locations. Although both genotype and environment had significant effects on Kieffer dough extensibility variables, environment represented the largest source of variation. Among genotype means, Area was most correlated (r = 0.63) with loaf volume, suggesting that by selecting lines with increased Area, loaf volume should improve. Rmax was positively correlated (r = 0.58) with loaf volume among genotype means but negatively correlated (r = –0.80) among environmental means. Ext was positively correlated (r = 0.90) with loaf volume among environmental means. Weather variables were correlated with Rmax, Ext and loaf volume and therefore could help predict end‐use quality.     

Evaluation of the Functionality of Five Different Soybean Proteins in Hot‐Press Wheat Flour Tortillas

Five different soybean protein sources were added to wheat flour to increase the protein content by 15–25%, and the resulting composite flours were optimally processed into hot‐press tortillas in a pilot plant. The rheological properties of composite flours were evaluated with the farinograph, alveograph, and other wheat quality tests. Tortilla‐making qualities of the control and soybean‐fortified flours were evaluated during dough handling, hot pressing, and baking. The resulting tortillas were tested in terms of yield, physical and chemical parameters, sensory properties, color, and objective and subjective texture. The soybean‐fortified tortillas had increased yields because of the higher dough water absorption and enhanced essential amino acid scores. Among the five different soybean proteins, the defatted soybean flour (SBM1) with the lowest fat absorption index and protein dispersibility index (PDI) and the soybean concentrate produced the best fortified tortillas. The protein meals with high PDI and relatively lower water absorption index (SBM3 and SBM4) produced sticky doughs, lower alveograph P/L values, and defective tortillas. All soybean proteins produced higher yields of tortillas with an enhanced protein quality and amount of dietary fiber.     

Effect of Flour Extraction Rate on White and Red Winter Wheat Flour Compositions and Tortilla Texture

Wheat flours commercially produced at 74, 80, and 100% extraction rates made from hard white winter wheat (WWF) and hard red winter wheat (WRF) were used to produce tortillas at a commercial-scale level. Flour characteristics for moisture, dry gluten, protein, ash, sedimentation volume, falling number, starch damage, and particle-size distribution were obtained. Farinograms and alveograms were also obtained for flour-water dough. A typical northern Mexican formula was used in the laboratory to test the tortilla-making properties of the flours. Then commercial-scale tortilla-baking trials were run on each flour. The baked tortillas were stored at room and refrigeration temperatures for 0, 1, 2, and 3 days. Maximum stress and rollability were measured every day. Tortilla moisture, color, diameter, weight, and thickness were measured for each treatment. Finally, tortilla acceptability was tested by an untrained sensory panel. Analyses of variance (ANOVA) were performed on the data. WWF had higher protein content, dry gluten, sedimentation volume, and water absorption than the WRF. The WWF was the strongest flour based on farinograph development time and alveograph deformation work. It also produced the most extensible dough measured with the alveograph (P/L). Flour protein and ash contents, water absorption, and tenacity increased directly with the flour extraction rate. Both WWF and WRF performed well in commercial-scale baking trials of tortillas. Tortillas made with both types of flours at 74 and 80% extraction rates had the best firmness and rollability. However, tortillas made with WWF 80% had the best color (highest L value). Tortillas prepared with 100% extraction rate flour were also well accepted by the sensory panel, had good textural characteristics, and became only slightly firm and slightly less rollable after three days of storage at room temperature.     

Adaptation of AACC Method 56‐11, Solvent Retention Capacity,for Use as an Early Generation Selection Tool for Cultivar Development

The solvent retention capacity (SRC) profile is useful for studying flour components contributing to end‐use functionality. The method tests four different solvents with 5 g of flour each. Because of the amount of grain (30–40 g) typically needed to produce 20 g of flour for the SRC test, the method is not well‐suited for assessing end‐use quality of early generation breeding material, where grain quantities are limited. The method was therefore modified to require only 0.2 g of ground wheat instead of 5 g of flour per SRC solvent. The small‐scale SRC results using whole meal had correlations of r = 0.86 for lactic acid, r = 0.85 for sodium carbonate, r = 0.78 for sucrose, r = 0.74 for sodium bicarbonate (the alkaline water retention capacity method) and r = 0.69 for water when compared with SRC values from full‐scale tests using 5 g of flour. Overall, cultivars with SRC values at the extremes of the distribution were in the same ranked order for the small‐ and large‐scale SRC test results. However, variation in ranked order of cultivars between test methods was detected among samples that were not at the extremes of the distribution. Traditionally, successful wheat breeding strategies involve eliminating or advancing lines from the extremes of the distribution to increase the proportion of desirable genotypes within breeding programs. Results indicated that advancing promising germplasm or eliminating germplasm with inferior end‐use quality potential is possible using the small‐scale SRC technique to evaluate early generation wheat breeding material, as a sort of breeding triage.     

Comparison of Asian Noodles from Some Hard White and Hard Red Wheat Flours

Asian noodles were prepared by an objective laboratory method that included adding optimum water to the dry ingredients, mixing the ingredients to homogeneous salt distribution, and sheeting of the dough under low shear stress. The lightness (L*) values of alkaline‐ and salt‐noodle doughs made from 65% extraction hard white wheat flours (except KS96HW115 flour at ≈70% extraction) were higher than those from 60% extraction hard red wheat flours (except Karl 92 flour at ≈70% extraction). A hard white spring wheat, ID377s, and a Kansas line of hard white winter wheat, KS96HW115, to be released in 2000, gave the highest L* values for dough sheets stored for 2 and 24 hr at 25°C. Cooking losses were 5–9 percentage points higher for alkaline noodles than salt noodles, but the cooking yields of the two types of Asian noodles were almost the same. Cooked alkaline noodles made from a high‐swelling flour (SP₉₃≈21 g/g) gave higher tensile strength than those made from several low‐swelling flours (SP₉₃ ≈15 g/g) with the same protein contents (≈12.5%). However, the cooked salt noodles gave the same tensile strength.     

Milling Quality and White Salt Noodle Color of Chinese Winter Wheat Cultivars

Improvement of milling quality is an important aspect in wheat breeding programs. However, the milling quality of Chinese wheats remains largely unexplored. Fifty‐seven Chinese winter wheat cultivars from four regions were used to investigate the variation of milling quality parameters and to determine the associations between milling quality traits and color of noodle sheet. Substantial variation was presented for all measured parameters in this germplasm pool. Complete soft, hard, and medium‐hard types were observed. Soft wheat and hard wheat show significant differences in flour ash content, flour bran area, and flour color grade. No simple trait can be used to select for flour milling quality. High flour ash content and bran speck area contributed negatively to brightness of dry flour. Correlation coefficients (r) between L* value of dry flour and flour ash content and bran speck area were ‐0.47 and ‐0.65 for hard cultivars, and ‐0.51 and ‐0.72 for soft cultivars, respectively. Flour color grade (FCG) was significantly and positively associated with bran speck area; r = 0.56 and 0.73 for hard and soft wheats, respectively. There was a high correlation between FCG and L* value of flour water slurry (r = ‐0.95). Strong associations were also established between milling quality index (MQI) and FCG, L* value of dry flour, flour‐water slurry, and white salted noodle sheet for both hard and soft wheats. In conclusion, substantial progress could be achieved in improvement of milling quality in Chinese winter wheats through genetic selection, and FCG and MQI could be two important parameters for evaluation of milling quality in breeding programs.     

Comparison of Quality Characteristics and Breadmaking Functionality of Hard Red Winter and Hard Red Spring Wheat

Various whole‐kernel, milling, flour, dough, and breadmaking quality parameters were compared between hard red winter (HRW) and hard red spring (HRS) wheat. From the 50 quality parameters evaluated, values of only nine quality characteristics were found to be similar for both classes. These were test weight, grain moisture content, kernel size, polyphenol oxidase content, average gluten index, insoluble polymeric protein (%), free nonpolar lipids, loaf volume potential, and mixograph tolerance. Some of the quality characteristics that had significantly higher levels in HRS than in HRW wheat samples included grain protein content, grain hardness, most milling and flour quality measurements, most dough physicochemical properties, and most baking characteristics. When HRW and HRS wheat samples were grouped to be within the same wheat protein content range (11.4–15.8%), the average value of many grain and breadmaking quality characteristics were similar for both wheat classes but significant differences still existed. Values that were higher for HRW wheat flour were color b*, free polar lipids content, falling number, and farinograph tolerance. Values that were higher for HRS wheat flour were geometric mean diameter, quantity of insoluble polymeric proteins and gliadins, mixograph mix time, alveograph configuration ratio, dough weight, crumb grain score, and SDS sedimentation volume. This research showed that the grain and flour quality of HRS wheat generally exceeds that of HRW wheat whether or not samples are grouped to include a similar protein content range.     

Investigation of a Small‐Scale Asymmetric Centrifugal Mixer for the Evaluation of Asian Noodles

A high throughput centrifugal mixer capable of using smaller amounts of flour (50 g) was evaluated for the production of oriental alkaline noodles. The unit requires a small footprint on a laboratory bench and offers variable speed mixing (300–3,500 rpm) for 5–60 sec. Three different mixing bowls, plain, pin, and paddle, were evaluated for the small‐scale production of alkaline noodles using straight‐grade flour derived from Canada Western Red Spring (CWRS) and Canada Prairie White Spring (CPSW) wheat. Under optimized mixing conditions (3,000 rpm for 30 sec), the pin and paddle bowls produced noodle dough with crumb size distribution and adhesion characteristics consistent with commercial requirements. The plain bowl produced dough with larger undesirable dough chunks and showed excessive heat buildup. Noodle sheets produced from this dough were not comparable in color characteristics to conventionally produced noodle sheets. Noodles prepared using the paddle mixer also displayed some significantly different color and texture characteristics than conventionally prepared noodles. However, raw noodle sheets or cooked noodles of either wheat class, prepared using the pin bowl mixer, displayed color values (L*, a*, and b*) at 2 and 24 hr and cooked noodle texture characteristics (bite, chewiness, resistance to compression, and recovery) comparable to a conventional laboratory‐scale Hobart type mixer. In addition to the very short mixing time and small equipment footprint for the centrifuge mixer, rapid throughput is enhanced by the ability to rapidly clean or interchange bowls and to potentially vary sample size to as little as 5 g. These attributes should be particularly useful in earlier generation breeder programs where large numbers of samples require rapid screening.     

Alternate Dough Preparation Protocol for Extensigraph Test of Dough Strength

The extensigraph is an internationally accepted method for measurement of physical properties of dough subjected to mechanical handling and resting. Standard extensigraph methods ( 1 , ISO 5530‐2) use the farinograph for the preparation of dough in the presence of 2% salt at reduced water absorption (farinograph absorption minus 2–3%). However, the dough so prepared is usually underdeveloped and drier than typically seen in common baking processes. In addition, the standard extensigraph test is time consuming and requires a large sample size. In this study, an alternate dough preparation protocol is proposed, consisting of a Swanson‐type pin mixer at reduced salt (1%) and elevated water absorption (farinograph absorption plus 4%). With the alternate method, dough is fully developed and similar to bread dough in physical properties. 1 is followed for dough rounding, molding, resting, and stretching by using the Brabender Extensograph‐E instrument. Strong correlations for resistance to extension (r = 0.90) and area (r = 0.92) were found between the modified and standard dough preparation methods. This protocol requires much less flour sample and significantly increases sample throughput.     

Protein Composition‐Functionality Relationships for a Set of Argentinean Wheats

Relationships between flour functional properties and protein composition were studied using a set of 138 Argentinean wheat samples. Among different protein groups, the incremental increase of gliadin with increasing grain protein content was highest followed by polymeric protein with albumin‐globulin content much lower. Functional properties could be divided into two groups based on dependence on protein composition. Properties such as dough extensibility and bake test loaf volume correlated highly with the percentage of polymeric protein in the grain. Properties such as mixograph dough development time were best correlated with the percentage of polymeric protein in the protein (PPP). Alveograph tenacity showed no significant dependence on PPP. as found previously for extensigraph maximum resistance, but it was correlated with the percentage of unextractable polymeric protein in the protein. Energy (W) appeared to be a more useful alveograph parameter for predicting flour quality.     

Measurement of Color,Gloss, and Translucency of White Salted Noodles: Effects of Water Addition and Vacuum Mixing

Sensory evaluation showed panelists could detect small differences in gloss and translucency in boiled white salted noodles (WSN) but sensory evaluation requires significant resources. Methods for the measurement of noodle gloss and translucency in boiled WSN were developed and the effects of hardness, protein, water addition, and vacuum mixing on these visual sensory characteristics and color (as measured by CIE L*, a*, and b*) were investigated. Noodles derived from hard wheats at low flour protein contents were more translucent than noodles from soft wheat flour at low protein. This trend changed at the highest flour protein contents observed. Translucency of the soft wheat noodles increased to levels equal to or exceeding the translucency of high protein hard wheat noodles. Translucency of all noodle varieties increased as flour protein increased. CIE L* decreased, a* increased, and b* increased when water addition to dough increased from 30 to 35%, but there was no further effect on color when water addition was increased to >35% for raw soft and hard WSN. Boiled noodle translucency was significantly increased when water addition to the dough was increased from 35 to 38% and when noodles made from soft wheat flour were mixed under vacuum. Vacuum mixing significantly increased gloss of boiled noodles made from soft wheat flours.     

Effects of Prolamins Encoded by Chromosomes 1B and 1D on the Rheological Properties of Dough in Near-Isogenic Lines of Bread Wheat

Fourteen bread wheat near-isogenic lines (NILs) with different alleles at 1B- and 1D-chromosome loci Glu-1, Glu-3 and Gli-1 coding for high molecular weight glutenin subunits (HMW-GS), low molecular weight-GS, and gliadins, respectively, were grown in replicated plots to investigate the individual and combined effects of glutenin and gliadin components on the rheological properties of dough as determined by the Chopin alveograph. NILs did not reveal significant differences in seed yield, protein content, kernel weight, test weight, flour yield, and starch damage. On the contrary, they had a large variation in alveograph dough tenacity P (55–93 mm), swelling G (17–26 mL) and strength W (140–252 J × 10^-4). The null alleles at the Gli-D1/Glu-D3 loci, and allele Glu-D1d (HMW-GS 5+10) were found to have a strong positive influence on dough tenacity and a remarkable negative influence on dough swelling (extensibility) when compared to alleles Gli-D1/Glu-D3b and Glu-D1a (HMW-GS 2+12), respectively. On the other hand, alleles Glu-B1c (HMW-GS 7+9) and Gli-B1/Glu-B3k gave greater G values than alleles Glu-B1u (HMW-GS 7*+8) and Gli-B1/Glu-B3b. The effects of individual Glu-1, Gli-1, or Glu-3 alleles on P and G values were largely additive. The impact of the null allele at Gli-D1/Glu-D3 on gluten strength was highly positive in NILs possessing HMW-GS 2+12, and negligible or negative in NILs containing HMW-GS 5+10, suggesting that there is scope for improving dough quality by utilizing this allele in combination with HMW-GS 2+12. Gli-D1/Glu-D3-encoded prolamins were shown to play a major role in conferring extensibility to dough, and could account for the superior breadmaking characteristics of bread wheat as compared to durum wheat.     

Genetic Variation in Color of Sweetpotato Flour Related to Its Use in Wheat-Based Composite Flour Products

Sweetpotato flours vary widely in color depending on genotype, and when used in wheat-based composite flours, they will impart characteristic colors which may be favorable or unfavorable for particular food products. Sweetpotato flour (SPF) was prepared from 44 genotypes and analyzed for proximate composition and biochemical properties. The Hunter Color L*, a*, b* values of the dry SPF and their modified Pekar slicks (PS) with water and with alkali were measured. Polyphenol oxidase activity, α-amylase activity, and total sugar were significantly correlated to L* values of dry SPF and of their PS tests with water and with alkali. The yellow pigment level was significantly correlated to the yellowness (b*) of the dry flour and of the PS test with water, but less correlated to b* of the PS test with alkaline. The results indicated a complex biochemical basis to SPF color, and no single biochemical factor examined was adequate to predict the color of a food product made from SPF. However, the PS color parameters were highly correlated with the color of dough sheets for white-salted and yellow-alkaline noodles made from wheat and sweetpotato composite flour (75:25). Thus, the simple modified PS test could be used in screening of genotypes for color stability and suitability for a specific end-use. SPF genotypes conferred a wide range of colors on composite flour dough preparations. Some colors, particularly the range of greens and bright orange, may be useful in specialty product development.     

Dough Microextensibility Method Using a 2‐g Mixograph and a Texture Analyzer

Development of a small‐scale method to measure dough extensibility, using a 2‐g mixograph and the TA.XT2 texture analyzer (TA) equipped with Kieffer rig, suitable for early‐generation wheat quality screening is presented. Three hook speeds 3.3, 7.0, and 10.0 mm/sec were tested on the TA. Only at the lower hook speed of 3.3 mm/sec were wheats, varying in quality, clearly differentiated. The ability to differentiate between wheats using the TA was compared with the Brabender Extensigraph. The sample ranking based on the resistance to extension (R_max) from the TA at a hook speed of 10.0 mm/sec correlated highly (r = 0.99) to the ranking obtained on the extensigraph. Dough extensibility data from the extensigraph and the TA, using hook speed 10.0 mm/sec, was correlated (r = 0.90) to loaf volume. Similarly, dough extensibility on the TA, using hook speed 3.3 mm/sec, was correlated to loaf volume (r = 0.96). The effect of three dough water contents (farinograph absorption, farinograph absorption + 6%, and 2‐g mixograph water absorption) on physical properties of dough were evaluated by mixing the dough in a 2‐g mixograph and testing the extensibility on the TA. Dough prepared at farinograph absorption + 6% and at mixograph absorption allowed differentiation between wheats based on the resistance to extension (R_max).     

A Fast,Simple, and Reliable Method to Predict Pasta Yellowness

Pasta yellowness depends on the semolina carotenoid content, carotenoid degradation by lipoxygenase (LOX), and pasta processing conditions. In breeding programs, early generation lines are selected for high grain yellow pigment content with the intent to improve pasta color. This approach has been successful in increasing the grain yellow pigment of Canadian durum wheat in the last few decades. In recent years, however, a weak relationship between pasta yellowness (b*) as measured by a Minolta spectrophotometer and semolina yellow pigment content (r = 0.19–0.52) was noted in the Canadian durum wheat lines. Thus, total semolina yellow pigment content cannot effectively predict the yellowness of its pasta product. Therefore, a fast and simple method was developed to predict pasta yellowness by measuring semolina dough sheet color at different time intervals after sheeting (0.5, 2.0, and 24 hr). Spaghettis were processed from the semolina samples at two drying temperature cycles (70 and 90°C). There were significant correlations between dough sheet b* values at all three times and spaghetti b* values at both drying temperatures (r = 0.87–0.94). Semolina dough sheet can be easily prepared in 15 min and requires only 30 g of material. Shortly after sheeting (30 min), dough sheet b* values can be used to predict pasta yellowness without producing the end product (involving mixing, extrusion, and drying). In this study, we also found that dough sheet b* values increased significantly with time over the sampling intervals after sheeting for those breeding lines with superior pasta color. DNA analysis revealed that all those lines lacked the Lpx‐B1.1 duplication.     

Prediction of Specific Japanese Sponge Cake Volume Using Pasting Properties of Flour

In Japanese soft wheat (Triticum aestivum L.) breeding programs, protein content (PC), and specific surface area (SSA) of flour have been used as important factors for the baking quality of Japanese sponge cake. We proposed batter pasting viscosity (BPV) as a parameter to predict the baking quality of Japanese sponge cake. BPV was measured using a Rapid Visco‐Analyser (RVA) with a modified heating profile. Twenty soft wheat samples from the 2006‐07 season and 22 from the 2007‐08 season, including Japanese soft wheat cultivars, advanced breeders' lines, and Western White (WW) imported from the United States, were milled and evaluated for solvent retention capacity (SRC) values of four solvents, batter pasting properties, flour pasting properties, PC, SSA, and specific cake volume (SCV) to investigate their relationships. BPV was the most strongly correlated of the parameters to SCV (r = –0.90, P < 0.001). Stepwise multiple regression analysis selected BPV and minimum viscosity (MV) of flour pasting as significant independent variables to predict SCV (corrected R² = 0.848). The variability in BPV related to cake batter expansion was highly explained by PC and sucrose SRC (corrected R² = 0.854, P < 0.001). MV was correlated to SSA (r = 0.56, P < 0.001) and might be related to the prevention of sponge cake shrinkage during baking.     

Effects of Salt,Polyethylene Glycol,and Water Content on Dough Rheology for Two Red Spring Wheat Varieties

In this research, the relationship between dough rheology and water behavior was investigated in response to two osmotic regulators, salt (NaCl) and polyethylene glycol (PEG), using two Canadian Western Red Spring (CWRS) wheat varieties (Harvest and Pembina). The effects of NaCl (0.5, 1.0, and 1.5 g/100 g of flour) and PEG 400 (2.5, 5.0, and 7.5 g/100 g of flour) on dough rheology (oscillatory and creep) were estimated by using a central composite design. Variation of NaCl showed a significant effect on the phase angle δ, indicating that increasing the NaCl resulted in a more elastic dough. The opposite trend was observed with the addition of PEG. PEG 400 exerted a softening effect owing to plasticization, so that a more compliant liquid‐like dough was produced. The effects of water content (±10% of farinograph absorption) and PEG molar mass on dough rheology and freezable water content were estimated by using a full factorial design. PEGs with different molar mass (400, ≈1,600, and 3,350 g/mol) were added at a concentration of 1 g/100 g of flour. The water content significantly affected all dough rheological attributes, whereas PEG molar mass had no effect. The complex shear modulus (G* ) decreased with increasing water content, and dough creep compliance (J _max) increased. The elastic response of dough, determined as the relative elastic part (J _el) decreased with increasing water content. A high correlation was found between the freezable water content and dough rheological attributes.