Evaluation of Various Baking Methods for Polished Wheat Flours

Flour qualities of polished wheat flours of three fractions, C‐1 (100–90%), C‐5 (60–50%), and C‐8 (30–0%), obtained from hard‐type wheat grain were used for the evaluation of four kinds of baking methods: optimized straight (OSM), long fermentation (LFM), sponge‐dough (SDM) and no‐time (NTM) methods. The dough stability of C‐5 in farinograph mixing was excellent and the maturity of polished flour doughs during storage in extensigraph was more improved than those of the commercial wheat flour (CW). There were no significant differences in the viscoelastic properties of CW dough after mixing, regardless of the baking method, while those of polished flour doughs were changed by the baking method; this tendency became clear after fermentation. The polished flours could make a better gluten structure in the dough samples after mixing or fermentation using LFM and SDM, as compared with other baking methods. Baking qualities such as specific volume and storage properties of breads from all polished flours made with SDM increased more than with other methods. In addition, viscoelastic properties of C‐5 and C‐8 doughs fermented by SDM were similar to those of CW, and the C‐5 breadcrumb showed softness similar to that of the CW. Also, SDM could make C‐5 bread with significantly higher elasticity and cohesiveness after storage for five days when compared with CW bread. Therefore, SDM with long fermentation, as compared with other baking methods, was considered suitable for use with polished flours to give better effects on dough properties during fermentation, resulting in more favorable bread qualities.     

Prediction of Baking Characteristics of Hard Winter Wheat Flours Using Computer‐Analyzed Mixograph Parameters

The objective of this research was to determine whether computer‐analyzed (objective) mixograph parameters could replace conventional mixograph parameters in the evaluation of flour quality. The 642 hard winter wheat flours, collected from federal regional performance nurseries in 1995 and 1996, were analyzed by a conventional and computerized mixograph. Mixograph bandwidths at 6 min (BW6) showed the most significant linear correlation with subjective mixing tolerance scores (r = 0.81, P < 0.1%, n = 642). Prediction models of conventional and experimental baking parameters were developed by continuum regression using computer‐analyzed mixograph parameters of a calibration set (n = 282). The developed models could estimate conventional mixograph mixing time and tolerance scores, baking water absorption and mixing time, and bread loaf volume, showing R² values of 0.86, 0.74, 0.68, 0.80, and 0.51, respectively, for a validation set (n = 380). These results indicated that computer‐analyzed mixograph parameters could be applied to develop prediction models to be used for flour quality evaluation in wheat breeding programs.     

Dough and Baking Properties of High‐Amylose and Waxy Wheat Flours

The dough properties and baking qualities of a novel high‐amylose wheat flour (HAWF) and a waxy wheat flour (WWF) (both Triticum aestivum L.) were investigated by comparing them with common wheat flours. HAWF and WWF had more dietary fiber than Chinese Spring flour (CSF), a nonwaxy wheat flour. Also, HAWF contained larger amounts of lipids and proteins than WWF and CSF. There were significant differences in the amylose and amylopectin contents among all samples tested. Farinograph data showed water absorptions of HAWF and WWF were significantly higher than that of CSF, and both flours showed poorer flour qualities than CSF. The dough of WWF was weaker and less stable than that of CSF, whereas HAWF produced a harder and more viscous dough than CSF. Differential scanning calorimetry data showed that starch in HAWF dough gelatinized at a lower temperature in the baking process than the starches in doughs of WWF and CSF. The starch in a WWF suspension had a larger enthalpy of gelatinization than those in HAWF and CSF suspensions. Amylograph data showed that the WWF starch gelatinized faster and had a higher viscosity than that in CSF. The loaves made from WWF and CSF were significantly larger than the loaves made from HAWF. However, the appearance of bread baked with WWF and HAWF was inferior to the appearance of bread baked with CSF. Bread made with WWF became softer than the bread made with CSF after storage, and reheating was more effective in refreshing WWF bread than CSF bread. Moreover, clear differences in dough and bread samples were revealed by scanning electron microscopy. These differences might have some effect on dough and baking qualities.     

小麦蛋白淀粉品质指标与面包品质关系的研究

选用近年来黄淮麦区大面积推广种植的小麦品种和新育成高代品系为材料,采用近红外(NIR)、面筋仪、粉质仪、快速粘度分析仪(RVA)和凝胶色谱(SE-HPLC)方法等对蛋白品质指标及淀粉糊化参数进行分析,分析各品质参数间的关系及其与面包烘焙品质的关系。结果表明,谷蛋白大聚体(GMP)、SDS(十二烷基硫酸钠)-沉降值、湿面筋指数、弱化度与多数蛋白品质指标间存在正向0.01或0.05水平相关,GMP、SDS-沉降值、湿面筋指数、干面筋含量、面粉蛋白含量、麦谷蛋白含量、形成时间、稳定时间均与面包烘焙品质间达0.01水平正相关,湿面筋含量与面包体积和评分间分别达0.01和0.05水平正相关;醇溶蛋白含量及弱化度与面包体积和评分间分别达0.05和0.01水平负相关。吸水率与糊化温度、最终粘度、回生值间达0.01水平负相关,形成时间与峰值粘度和稀澥值间达0.05水平正相关,GMP与糊化温度间达0.05水平负相关。各品质参数对面包体积的作用大小依次为湿面筋指数>弱化度>形成时间>湿面筋含量>糊化温度等,对面包评分的作用大小依次为麦谷蛋白>稳定时间>醇溶蛋白>面粉蛋白含量>吸水率等。小麦品质测试指标间有着广泛的相关性,湿面筋指数、弱化度和麦谷蛋白、稳定时间是反映面包烘焙品质的重要指标;早代可进行GMP或SDS-沉降值测定,中高代可进行面筋仪、粉质仪测定;在品质测试过程中应重视湿面筋指数、弱化度的重要性,小麦粉淀粉品质对面包品质的影响也应引起关注。     

Relationships of Free Lipids with Quality Factors in Hard Winter Wheat Flours

Hard winter wheat (Triticum aestivum L.) flours (n = 72) were analyzed for free lipids (FL) and their relationships with quality parameters. The two main glycolipid (GL) classes showed contrary simple linear correlations (r) with quality parameters. Specifically, kernel hardness parameters, flour yields, and water absorptions had significant negative correlations with monogalactosyldiglycerides (MGDG) but positive correlations with digalactosyldiglycerides (DGDG). MGDG showed negative correlations with gluten content but positive correlations with gluten index. The percentages of DGDG in FL had significant positive correlations among cultivars (n = 12) with mixograph and bake mix times (r = 0.71, P < 0.01 and r = 0.67, P < 0.05, respectively), mixing tolerance (r = 0.67, P < 0.05), and bread crumb grain score (r = 0.71, P < 0.01). These results suggest that increasing DGDG in FL could contribute to enhancing wheat quality attributes including milling, dough mixing, and breadmaking quality characteristics. FL content and composition (ratio of MGDG or DGDG to GL) supplement flour protein content to develop prediction equations of mixograph mix time (R² = 0.89), bake mix time (R² = 0.76), and loaf volume (R² = 0.72).     

Baking Quality of Bread Wheat Cultivars Damaged by Nysius simulans

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

Impact of Characteristics of Different Wheat Flours on the Quality of Frozen Cooked Noodles

In this study, the impact of characteristics (physicochemical, rheological, and pasting properties) of different wheat flours on the quality of frozen cooked noodles was investigated. In this sample set, results showed the cooking loss of noodles related negatively to flour swelling power. The water absorption of noodles related negatively to the dough stability time, the area, and the resistance to extension. The wheat flour with higher dough development time resulted in frozen cooked noodles with higher hardness, chewiness, and adhesiveness. Springiness of noodles correlated negatively to degree of softening. The tensile properties of frozen cooked noodles were influenced by rheological and pasting properties of wheat flours. The present study indicated high quality of frozen cooked noodles demanded wheat flours with high dough gluten strength, peak viscosity, and final viscosity and with low pasting temperature.     

Significance of Wheat Flour Particle Size on Sponge Cake Baking Quality

We evaluated the effect and magnitude of flour particle size on sponge cake (SC) baking quality. Two different sets of wheat flours, including flours of reduced particle size obtained by regrinding and flour fractions of different particle size separated by sieving, were tested for batter properties and SC baking quality. The proportion of small particles (<55 μm) of flour was increased by 11.6–26.9% by regrinding. Despite the increased sodium carbonate solvent retention capacity, which was probably a result of the increased starch damage and particle size reduction, reground flour exhibited little change in density and viscosity of flour‐water batter and produced SC of improved volume by 0.8–15.0%. The volume of SC baked from flour fractions of small (<55 μm), intermediate (55–88 μm), and large (>88 μm) particles of soft and club wheat was in the range of 1,353–1,450, 1,040–1,195, and 955–1,130 mL, respectively. Even with comparable or higher protein content, flour fractions of intermediate particle size produced larger volume of SC than flour fractions of large particle size. The flour fractions of small particle size in soft white and club wheat exhibited lower flour‐water batter density (102.6–105.9 g/100 mL) than did those of large and intermediate particle fractions (105.2–108.2 g/100 mL). The viscosity of flour‐water batter was lowest in flour fractions of small particle size, higher in intermediate particles, and highest in large particles. Flour particle size exerted a considerable influence on batter density and viscosity and subsequently on SC volume and crumb structure. Fine particle size of flour overpowered the negative effects of elevated starch damage, water absorption, and protein content in SC baking.     

Effect of Enzymatic Tempering of Wheat Kernels on Milling and Baking Performance

This study examined the effect of cell‐wall‐degrading enzymes added to temper water on wheat milling performance and flour quality. An enzyme cocktail consisting of cellulase, xylanase, and pectinase and five independent variables (enzyme concentration, incubation time, incubation temperature, tempered wheat moisture content, and tempering water pH) were manipulated in a response surface methodology (RSM) central composite design. A single pure cultivar of hard red winter wheat was tempered under defined conditions and milled on a Ross experimental laboratory mill. Some treatment combinations affected flour yield from the break rolls more than that from the reduction rolls. However, a maximum for flour yield was not found in the range of parameters studied. Though treatments did not affect the optimum water absorption for breadmaking, enzyme‐treated flours produced dough exhibiting shorter mixing times and slack and sticky textures compared with the control. Regardless of differences in mixing times, specific loaf volumes were not significantly different among treatments. Crumb firmness of bread baked with flour milled from enzyme‐treated wheat was comparable to the control after 1 day but became firmer during storage up to 5 days.     

Gluten,Pasting, and Mixograph Parameters of Hard Winter Wheat Flours in Relation to Breadmaking

Flour gluten, pasting, and mixogram characteristics of 12 hard winter wheat cultivars grown in six counties in Kansas were analyzed using the Glutomatic System, a Rapid Visco-Analyser, and MIXSMART computer software, respectively, to investigate their relationships with breadmaking. Gluten contents and hydration amounts had significant correlations with water absorption. In addition, gluten parameters were significantly correlated to kernel hardness. One of the most difficult challenges in mixograph usage is to find the optimum water absorption of a given flour. Flour protein contents (FP) and near-infrared hardness scores or FP and gluten parameters could predict mixograph water absorptions, showing R² values of 0.842 or 0.814, respectively, by multiple regression analysis. For our set of 72 wheat samples, computer-analyzed mixograph parameters were significantly correlated to conventional parameters. Computer-analyzed mixograph midline peak times and bandwidths at 6 min were highly correlated to conventional mixograph mix times and mixing tolerances, respectively. Flour pasting temperatures complemented FP in predicting loaf volumes. The ratios of FP to pasting temperatures had a significant curvilinear relationship with loaf volumes showing an R² of 0.725.     

Protein Profile and Molecular Markers Related to the Baking Quality of Brazilian Wheat Cultivars

To carry out wheat breeding programs, proteins were identified and quantified (through sodium dodecyl sulfate polyacrylamide gel electrophoresis [SDS‐PAGE] and size‐exclusion high‐performance liquid chromatography [SE‐HPLC]) and six allele‐specific markers were tested on 45 Brazilian cultivars. A microscale baking test was applied to associate analytical and genetic responses with baking quality. The results suggested a prevalence of the subunits 2* and 1 in chromosome 1A; 7+8, 7+9, and 17+18 in 1B; and 5+10 in 1D; absence of 1BL/1RS translocation in 62.2% of the genotypes; and presence of Pinb‐D1b and Glu‐A3d in 8.9% of the genotypes. The average SE‐HPLC values were 37.50 and 45.42% for polymeric protein in total protein (PPP) and unextractable polymeric protein (UPP), respectively, and 1.29 for the gliadin‐to‐glutenin (GLI/GLU) ratio, with significant variation among the genotypes (P ≤ 0.05). The baking test also showed a significant difference (P ≤ 0.05) between the cultivars under the same conditions. The cultivars without the 1BL/1RS translocation with rye also showed better results for UPP, PPP, and GLI/GLU in relation to those possessing translocation. These results corroborate for selection of HMW subunits 5+10, cultivars without translocation with rye, with high UPP values and a balanced GLI/GLU ratio (around 1.0) with the objective of obtaining greater wheat baking quality.     

Baking Performance of Durum and Soft Wheat Flour in a Sponge-Dough Breadmaking Procedure

Breadmaking properties were determined for formulations that included durum, soft, and spring wheat flour, using a pound-loaf sponge-dough baking procedure. Up to 60% durum or soft wheat flour plus 10% spring wheat flour could be incorporated at the sponge stage for optimum dough-handling properties. At remix, the dough stage required 30% spring wheat flour. Bread made with 100% spring wheat flour was used as a standard for comparison. Bread made with 60% durum flour exhibited internal crumb color that was slightly yellow. When storing pound bread loaves for 72 hr, crumb moisture content remained unchanged. Crumb firmness and enthalpy increased the most in bread made with 60% soft wheat flour. Crumb firmness increased the least in bread made with 100% spring wheat flour. Enthalpy changed the least in bread made with 60% durum flour. Crumb moisture content was significantly correlated with crumb firmness (r = -0.82) and enthalpy (r = -0.65). However, crumb moisture content was specific for each type of flour and a function of flour water absorption; therefore, these correlations should be interpreted with caution. Crumb firmness and enthalpy were significantly correlated (r = 0.65). Ball-milling flour resulted in an increase in water absorption of ≈2% and in crumb moisture content of ≈0.5% but had no effect on either crumb firmness or enthalpy.     

Bran Characteristics and Bread‐Baking Quality of Whole Grain Wheat Flour

Variations in physical and compositional bran characteristics among different sources and classes of wheat and their association with bread‐baking quality of whole grain wheat flour (WWF) were investigated with bran obtained from Quadrumat milling of 12 U.S. wheat varieties and Bühler milling of six Korean wheat varieties. Bran was characterized for composition including protein, fat, ash, dietary fiber, phenolics, and phytate. U.S. soft and club wheat brans were lower in insoluble dietary fiber (IDF) and phytate content (40.7–44.7% and 10.3–17.1 mg of phytate/g of bran, respectively) compared with U.S. hard wheat bran (46.0–51.3% and 16.5–22.2 mg of phytate/g of bran, respectively). Bran of various wheat varieties was blended with a hard red spring wheat flour at a ratio of 1:4 to prepare WWFs for determination of dough properties and bread‐baking quality. WWFs with U.S. hard wheat bran generally exhibited higher dough water absorption and longer dough mixing time, and they produced smaller loaf volume of bread than WWFs of U.S. soft and club wheat bran. WWFs of two U.S. hard wheat varieties (ID3735 and Scarlet) produced much smaller loaves of bread (<573 mL) than those of other U.S. hard wheat varieties (>625 mL). IDF content, phytate content, and water retention capacity of bran exhibited significant relationships with loaf volume of WWF bread, whereas no relationship was observed between protein content of bran and loaf volume of bread. It appears that U.S. soft and club wheat bran, probably owing to relatively low IDF and phytate contents, has smaller negative effects on mixing properties of WWF dough and loaf volume of bread than U.S. hard wheat bran.     

Influence of Kernel Size and Shriveling on Soft Wheat Milling and Baking Quality

Small kernels of soft wheat are sometimes considered to be harder than larger kernels and to have inferior milling and baking characteristics. This study distinguished between kernel size and kernel shriveling. Nine cultivars were separated into large, medium, and small kernels that had no shriveling. Eleven cultivars were separated into sound, moderate, and severely shriveled kernels. Shriveling greatly decreased the amount of flour produced during milling. It adversely affected all other milling quality characteristics (ash content, endosperm separation index, and friability). Shriveled kernels produced flour that had inferior soft wheat baking qualities (smaller cookie diameter and higher alkaline water retention capacity). In contrast, test weight and milling qualities were independent of kernel size. Small, nonshriveled kernels had slightly better baking quality (larger cookie diameter) than larger nonshriveled kernels. Small kernels were softer than large kernels (measured by break flour yield, particle size index, and flour particle size). Small nonshriveled kernels did not have diminished total flour yield potential or other reduced flour milling characteristics. Those observations suggest a possibility of separating small sound kernels from small shriveled kernels to improve flour yield and the need to improve dockage testing estimation techniques to distinguish between small shriveled and small nonshriveled kernels.     

Physicochemical and Rheological Properties of Chinese Soft Wheat Flours and Their Relationships with Cookie‐Making Quality

The relationship of solvent retention capacity (SRC) values with four solvents, alveograph and farinograph properties, and cookie‐baking performance was evaluated with 20 Chinese soft wheat genotypes, including four cultivars and 16 advanced lines grown in the 2009–2010 season. Significant positive correlations were observed between water SRC (WSRC), sodium carbonate SRC (SOSRC), lactic acid SRC, and sucrose SRC (SUSRC) values. WSRC, SUSRC, and SOSRC showed significant positive correlations with farinograph water absorption (WA), alveograph P (tenacity), and P/L (ratio of tenacity to extensibility). Cookie diameter was significantly correlated with wet gluten (r = –0.491, P < 0.05), WSRC (r = –0.882, P < 0.001), SUSRC (r = –0.620, P < 0.01), SOSRC (r = –0.712, P < 0.001), P (r = –0.787, P < 0.001), L (r = 0.616, P < 0.01), P/L (r = –0.766, P < 0.001) and WA (r = –0.620, P < 0.01), respectively. SRC values were effective predictors of cookie quality in Chinese soft wheat. Alveograph parameters were more closely correlated to cookie quality than were farinograph parameters.     

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

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

Factors Governing Pasting Properties of Waxy Wheat Flours

Waxy wheat (Triticum aestivum L.) contains endosperm starch lacking in amylose. To realize the full potential of waxy wheat, the pasting properties of hard waxy wheat flours as well as factors governing the pasting properties were investigated and compared with normal and partial waxy wheat flours. Starches isolated from six hard waxy wheat flours had similar pasting properties, yet their corresponding flours had very different pasting properties. The differences in pasting properties were narrowed after endogenous α‐amylase activity in waxy wheat flours was inhibited by silver nitrate. Upon treatment with protease, the extent of protein digestibility influenced the viscosity profile in waxy wheat flours. Waxy wheat starch granules swelled extensively when heated in water and exhibited a high peak viscosity, but they fragmented at high temperatures, resulting in more rapid breakdown in viscosity. The extensively swelled and fragmented waxy wheat starch granules were more susceptible to α‐amylase degradation than normal wheat starch. A combination of endogenous α‐amylase activity and protein matrix contributed to a large variation in pasting properties of waxy wheat flours.     

Determination of Surface Tension Properties of Wheat Endosperms,Wheat Flours,and Wheat Glutens

During wheat dough processing, a large part of the interactions with water are governed by wettability properties of flour. The wettability properties of wheat materials (flat slices of wheat endosperm, flour‐based pellets, and gluten‐based pellets) were assessed by the measurement of contact angles of a sessile drop of three reference liquids (water, diiodomethane, and formamide) and estimated by equilibrium properties (contact angles and surface tension properties) and drop penetration rates. The surface tension (γ_s) of wheat materials was measured between 49.6 and 55.3 mJ/m^‐2. The present work permitted the evaluation of specific wheat types (hard wheat vs. soft wheat) and evaluation of the influence of material structure (flat slices of endosperm vs. flour‐based pellets), and material nature (flour‐based pellets vs. gluten‐based pellets) on the wettability properties. The surface tension properties were considered with regard to the nonideal structure of sample surfaces by considering surface roughness and material porosity.     

Environmental Influences on Flour Composition,Dough Rheology,and Baking Quality of Spring Wheat

The highly variable environmental conditions across the Pacific Northwest (PNW) influence the milling and baking quality of wheat grain produced in this region. This study was conducted to compare the flour composition, dough rheology, and baking quality of soft and hard spring wheat grain produced in diverse environments. Thirteen soft and five hard spring wheat cultivars were grown at Lind, WA (semiarid) and Fairfield, WA (high precipitation) for three years. Grain was evaluated for flour composition, rheology, and experimental baked product quality. Flour composition, rheological properties, and baking qualities were primarily influenced by the environment. Protein contents, microSDS values, and water absorption levels were significantly (P < 0.0001) higher for all cultivars grown at Lind compared with those from Fairfield. Cookie diameters were larger (P < 0.0001) for soft flours from Fairfield, whereas loaf volumes were higher (P < 0.0001) for hard wheat flours from Lind. Results indicate that producing soft or hard wheat outside of its optimal climatic zone reduces experimental baked product quality.