Farinograph Development Time Research Articles

Comparison of quality, dietary fiber and glycemic index of whole wheat breads using various modern and old wheats and investigate the effect of xylanase

Six bread wheat varieties (modern wheats) widely grown in Turkey and nine different bread wheat varieties registered prior to 1970 (old wheats) were used in the present study. This study aimed to determine and compare the quality characteristics, dietary fiber contents and in vitro glycemic index of whole wheat breads produced using modern and old bread wheat varieties. The effect of xylanase on the quality, staling and dietary fiber content of whole wheat breads was also investigated. Mean sedimentation and modified sedimentation values, Farinograph development time, stability, quality number of whole wheat flours produced by modern wheats were higher than those of the old varieties. Whole wheat breads of modern varieties had higher mean volume and lower firmness values as compared to old varieties. Whole wheat breads of old wheat varieties had higher mean soluble dietary fiber content as compared to that of modern wheat varieties. Xylanase addition generally had an increasing effect on bread volume and soluble dietary fiber contents and a softening effect on firmness values. There were no significant differences between the mean (in vitro) glycemic index values of whole wheat breads produced from modern and old varieties. The results in the present study indicated that modern bread wheat varieties had better whole wheat bread making quality as compared with old bread wheat varieties. In addition, xylanase usage in whole wheat bread formula had an improving effect on whole wheat bread quality.

Effects of years on farınograph parameters and qualıty characterıstıcs

This study was conducted to determine the farinograph parameters and some quality characteristics of 15 bread wheat varieties grown in rainfed conditions in 2011-2012, 2012-2013 and 2013-2014 according to a randomized block trial design with two replication. The farinograph parameters (development time, water absorption, stabilsity and softening at the 12th minute), protein ratio, grain hardness, Zeleny sedimentation and bread volume of bread wheat varieties were investigated. Three-year average value ranges of quality traits; protein ratio 13.51-16.02%, grain hardness PSI 45.74-71.05, Zeleny sedimentation 34.67-63.67 ml, bread volume 340-519.17 cm3, farinograph development time 3.75-12.30 min., farinograph water absorption 57.43-65.72%, farinograph stability 4.62-16.92 min. and the farinograph 12 min. softening value 38.66-132.33% was determined as. Significant quality differences were determined between varieties and years, and the highest values in terms of quality traits were obtained in 2013-2014. High values were obtained in Konya-2002, Tosunbey, Karahan-99 and Eraybey varieties in terms of farinograph development time, water absorption and stability values.

The Characteristics of Steamed Bread from Reconstituted Whole Wheat Flour (WWF) of Different Hard Wheat Classes with Different Bran Particle Size Distributions.

The purpose of this study was to investigate the effects of reconstituted whole wheat flour (WWF) particle size on flour characteristics and northern-type steamed bread (NTSB) quality. In this study, hard white (HW), hard red winter (HRW), and hard red spring (HRS) wheat classes, and four different bran particle size distributions [D(50) values of 53 μm, 74 μm, 105 μm, and 125 μm] were blended at a ratio of 85% refined flour + 15% bran to create reconstituted WWF and make reconstituted WWF NTSB. Farinograph water absorption and water solvent retention capacity (SRC) increased as bran particle size decreased. Flour and dough strength tests such as lactic acid SRC and Farinograph and Mixolab development time and stability did not show any clear trends with bran particle size. HRW WWF tended to be the exception as Farinograph development time and stability generally increased as particle size increased. Resistance to extension increased as bran particle size decreased for HRW WWF and increased as particle size increased for HW and HRS. These differences in WWF dough rheology trends were likely due to differences in gluten characteristics between the classes. The results showed that larger particle sizes (105 μm and 125 μm) were more conducive to achieving desirable whole wheat NTSB specific volume, color, and texture.

Determination of the Effect of Different Growing Conditions on the Farinograph Characteristics of Some Bread Wheat Varieties

Bu çalışma, 14 ekmeklik buğday çeşidinin farinograf özelliklerine kuru ve sulu yetiştirme koşullarının etkisini belirlemek amacıyla Bahri Dağdaş Uluslararası Tarımsal Araştırma Enstitüsünde 2014-2015 yılı yetiştirme döneminde tesadüf blokları deneme desenine göre 3 tekerrürlü olarak yürütülmüştür. Ekmeklik buğday çeşitlerinin farinograf parametreleri (gelişme süresi, su absorbsiyonu, stabilite, 10. ve 12. dakika yumuşama değeri) incelenmiştir. Kuru ve sulu koşullarda yetiştirilen çeşitler arasındaki farklar istatistiki olarak değerlendirilmiştir. Farinograf gelişme süresi (p<0.001), su absorbsiyonu (p<0.001), stabilite (p<0.001), 10. dakika yumuşama değeri (p<0.001) ve 12. dakika yumuşama değeri (p<0.001) arasındaki farklar önemli bulunmuştur. Sulu koşullarda gelişme süresi, su absorbsiyonu ve stabilite değerlerinin kuru koşullarda elde edilen değerlerden daha yüksek, 10. ve 12. dakika yumuşama değerlerinin ise daha düşük olduğu belirlenmiştir.

Application of chemometrics to prediction of some wheat quality factors by near‐infrared spectroscopy

AbstractBackground and objectivesPhysical quality parameters of wheat include kernel texture and test weight, which affect classification, grading, and price. Physicochemical factors are associated with flour functionality. The objective of the work was to determine the effectiveness with which these factors could be predicted in early generations using near‐infrared spectroscopy (NIRS). Wheat breeders need to know how their new genetic lines carry these factors, which carry no identifiable absorbers in the NIR region, can be predicted in early generations, by experts in the use of NIRS and its associated chemometrics.FindingsWith the exception of protein content, for which absorbers are plentiful, and was included to verify the spectral quality of the sample sets, none of the strictly physical factors could be reliably predicted with the most widely used chemometric options in the hands of experts in their use. Random forest algorithms were capable of prediction of all physicochemical factors, except Farinograph development time, with a reasonable degree of reliability.ConclusionsReliable predictions of quality factors in wheat that can be predicted by NIRS with satisfactory reliability are limited to chemical and physicochemical factors for which absorbers exist in the NIR region.Significance and noveltyChemical, physicochemical, and physical factors can be predicted with acceptable reliability by NIRS using a computerized spectrophotometer in association with Random Forest software. Farinograph development time remains a challenge for NIRS application.

Determining the Diversity of Bread Wheat Variteties on Yield and Quality Traits at Rainfed and Irrigated Conditions

This study was conducted with 7 bread wheat varieties in rainfed and irrigated conditions at Bahri Dagdas International Agricultural Research Institute as a randomized complete block design with three replications. Grain yield, thousand kernel weight, protein ratio, Zeleny sedimentation value, bread weight, bread volume and farinograph traits were investigated. Significant differences between the varieties were determined in terms of investigated traits in rainfed and irrigated conditions. Bread volume, farinograph development time, protein ratio and Zeleny sedimentation values in rainfed conditions were higher than values in irrigated conditions. Bread volume, farinograph development time, protein ratio and Zeleny sedimentation were determined as 507 cm 3 , 9.2 min, 13.6% and 46.8 ml in rainfed conditions and 495 cm 3 , 6.7 min., 12.3% and 44.0 ml in irrigated conditions respectively. According to the results; the effect of the growing conditions was found statistically significant on wheat quality.

Characterizing whole‐wheat flours produced using a commercial stone mill, laboratory mills, and household single‐stream flour mills

Background and objectivesOne hard wheat and one semi‐hard wheat were milled on commercial, laboratory, and household‐scale flour mills with rotating elements ranging from 0.1 to 1.0 m in diameter and speeds ranging from 65 to 40,000 rpm. The aim of the study was to assess and compare the quality of the flour from each of mills.FindingsPasting viscosities, Farinograph development time and stability, and loaf volumes (LVOL) were all markedly influenced by whole‐wheat flour particle size, which differed markedly between mills. LVOLs were acceptable using the flours produced by all the mills. Best flour quality came from the three mills that produced the finest whole‐wheat flour. Of these, the superior flour came from the 1.0‐m‐diameter Osttiroler stone mill. This mill produced whole‐wheat flours with more optimal levels of starch damage and higher water absorption than did the smaller mills. There was no evidence of degradation of gluten functionality even at a flour temperature of 51°C.ConclusionsThe mill used affected almost all flour quality traits. However, the characteristics of the wheat applied to the mill were the dominant influence on flour functionality. Starch damage may better indicate milling severity than the heat generated during the milling process.Significance and noveltyThis is the only study, that we know of, on the comparative performance of household‐scale flour mills. The study also presents an alternative way of visualizing particle size distributions of flours.

Cluster Analysis of Historical and Modern Hard Red Spring Wheat Cultivars Based on Parentage and HPLC Analysis of Gluten‐Forming Proteins

Thirty hard red spring (HRS) wheat cultivars released between 1910 and 2013 were analyzed to determine how they cluster in terms of parentage and HPLC analysis of gliadins and unreduced proteins. Markers for reduced height genes were assessed to determine associations between semidwarfism and protein composition, as well as quality characteristics. In terms of parentage, the clusters formed were grouped according to release year and semidwarfism. Farinograph development time and stability showed significant (P ≤ 0.05) differences between clusters, indicating improvement of mixing characteristics over time. Flour ash content was significantly different (P ≤ 0.05) between clusters, indicating improved milling quality. The clusters based on the gliadin reverse‐phase HPLC peak binary data did not group cultivars according to release year and the semidwarf characteristic. However, cultivars were grouped according to year in the absorbance area based dendrogram. The clusters based on absorbance area of size‐exclusion HPLC showed significant (P ≤ 0.05) differences for release year, the semidwarf characteristic, and farinograph stability. Overall, the results indicate that the introduction of reduced height genes accompanied the improvements of dough mixing and breadmaking quality characteristics, without altering the composition of gliadin proteins over the last 100 years of HRS wheat breeding.

Development of an Aegilops longissima substitution line with improved bread-making quality

This study focuses on the effect of Aegilops longissima on wheat bread making quality. Chromosome 1Sl disomic addition line of Ae. longissima (DAL1Sl) had significantly higher dough strength, grain hardness, mixographic peak height, band width, and unextractable polymeric protein content compared with wheat. DAL1Sl also had additional glutenin and gliadin proteins contributed by Ae. longissima. The larger size of 1Sl coded HMW-GSs sequenced from DAL1Sl and their phylogenetic similarity to the D-genome-coded subunits were suspected to be one of the major reasons for the increased dough strength of DAL1Sl. To transfer the chromosome 1Sl genes responsible for the good bread-making quality to wheat, we generated a chromosome-specific disomic substitution line [DSL1Sl(1A)] by crossing DAL1Sl with nulli 1A tetra 1B genetic stock and further selection. Grain quality analysis revealed significantly lower grain hardness and significantly higher dough strength, farinograph development time, stability time, gluten index, bread loaf volume, and bread quality score in DSL1Sl(1A), compared with wheat. However, the increased bread loaf volume and quality were not proportional to the relatively higher increases in dough strength and gluten index, indicating importance of other traits influencing bread making quality. The presence of a minor hardness locus on chromosome 1A is speculated.

THE PRODUCTIVITY OF SOFT WHEAT AND SOME OF ITS TECHNOLOGICAL INDICATORS AND CORRELATIONS AMONG THEM AT DIFFERENT IRRIGATION RATES

Wheat is the most important strategic crops in Syria because it supports the national economy and provides a loaf of bread. The evaluation of wheat validity or its suitability for the bread production as well as the quality of the resulted bread, depends on its flour characterizations and character of formed dough as well as on quality of the resulted bread. Three water treatments were applied as follows: 500, 400, 300 ml on seven varieties and five promising lines of bread wheat selected at ICARDA. After the harvest and getting the productivity, the protein and Farinograph test were assessed. Response of varieties and lines differed, depending on the water treatments. Also in the same water treatment the productivity varied among them clearly, but not associated with any of the studied technological indicators. A correlation relation between the percentage of protein and the irrigation rate, as well as between the Farinograph development time (FDT) and Farinograph Mixing Tolerance (FMT), was observed. Quality of the dough varied according to studied plant material and also by applied water treatment. Plant material studied was divided into four groups: two groups of them characterized weak dough to medium strength which were suitable for the Arabic bread, and other two characterized by strong dough to very strong which, were more suitable for French bread.

Pan Bread and Chinese White Salted Noodle Qualities of Chinese Winter Wheat Cultivars and Their Relationship with Gluten Protein Fractions

ABSTRACTImprovement of food processing quality has become a major breeding objective in China. Nineteen Chinese leading winter wheat cultivars with improved quality and two Australian cultivars with high bread and noodle‐making qualities were sown in four locations for two years to investigate dough properties, pan bread, and Chinese white salted noodle (CWSN) qualities, and their association with the quantity of protein fractions. The results indicated that genotype, environment, and genotype‐by‐environment interaction significantly affected most of quality traits and amount of protein fractions. Genotype mainly determined the quantity of gluten protein fractions and pan bread quality parameters, while environment was the most important source of variation for the noodle quality parameters. Chinese cultivars were characterized by acceptable protein content (11.1–13.4%), medium to strong dough strength (maximum resistance 176.9–746.5 BU), medium to poor dough extensibility (166.5–216.4 mm), fair to very good pan bread qualities, and good to very good CWSN qualities. Gliadin contributed more in quantity to protein content (r = 0.80, P < 0.001), however, glutenin and its subgroups were more important to dough strength. The quantity of glutenin, HMW‐GS, and LMW‐GS were highly and significantly correlated with dough strength‐related traits such as farinograph development time, stability, extensigraph maximum resistance, and extension area (r = 0.70–0.91, 0.65–0.89, and 0.70–0.91, respectively; P < 0.001). The quantity of LMW‐GS could explain 82.8% of the total variation of dough maximum resistance. The quantity of gliadin and the ratio of HMW‐GS to LMW‐GS determined dough extensibility (r = 0.75 and r = –0.59, respectively; P < 0.001 and P < 0.01, respectively). Higher quantity of glutenin and lower ratio of gliadin to glutenin resulted in higher bread score with r = 0.70 (P < 0.001) and r = –0.74 (P < 0.001), respectively. However, protein content and its fractions have a moderate undesirable effect on CWSN parameters such as color, firmness, and taste. Therefore, both allelic variation and quantity of storage protein fractions should be considered in breeding cultivars with improved pan bread making quality.

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

ABSTRACTWheat 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.

Contribution of common wheat protein fractions to dough properties and quality of northern-style Chinese steamed bread

Thirty-three cultivars and advanced lines originated from China, Mexico, and Australia were sown in four environments in Chinese spring wheat regions to investigate the association between gluten protein fractions determined by reversed-phase high-performance liquid chromatography (RP-HPLC), and dough properties and northern-style Chinese steamed bread (CSB) quality. The genotypes were divided into two groups of 10 and 23 entries with and without the 1B/1R translocation, respectively. 1B/1R translocation lines had significantly high amounts of ω-gliadins, and low levels of glutenin and low molecular weight glutenin subunits (LMW-GS), but no significant difference in dough properties and CSB quality from non-translocation lines. The association between protein fractions and dough properties, and CSB quality largely depended upon the presence of 1B/1R translocation. Gliadin contributed more in quantity to flour protein content (FPC) than glutenin, while glutenin and its fractions contributed more to dough strength and CSB quality. Among non-translocation lines, moderate to high correlation coefficients between quantified glutenin and its fractions, and farinograph development time (DT, r = 0.85 –0.92) and stability (ST, r = 0.81 –0.93), extensograph maximum resistance ( R max, r = 0.90 –0.93), CSB stress relaxation (SR, r = 0.55 –0.61) and CSB score ( r = 0.56 –0.62), were observed. Gliadin:glutenin ratios showed significant and negative associations with dough properties and CSB quality. Correlation coefficients between gliadin:glutenin, gliadin:HMW-GS, gliadin:LMW-GS ratios, and CSB score were −0.79, −0.73, and −0.79 among non-translocation lines, respectively. HMW-GS and LMW-GS, x-type HMW-GS and y-type HMW-GS contributed similarly to dough properties and CSB quality for non-translocation lines. Weak correlations between protein fractions and dough properties, and CSB quality were observed among translocation lines. This information should be useful for improvement of dough properties and CSB quality.

Effects of Nitrogen and Sulfur Fertilization on Commercial‐Scale Wheat Quality and Mixing Requirements

ABSTRACTThe effect on physical dough properties of nitrogen and sulfur fertilizer applied during cultivation was observed in two trials using the bread wheat (Triticum aestivum) cultivar Otane. Wheat flours from both trials were evaluated for physical dough properties under laboratory conditions and also under industrial conditions in the second trial. The laboratory and industrial optimum mechanical dough development (MDD) work input (WI) significantly increased when nitrogen (N) fertilizer was applied without sulfur fertilizer (S) during crop cultivation. With combined N and S fertilization, laboratory and industrial WI remained close to levels for grain grown without fertilizer. Reductions in extensigraph resistance to extension (Rmax) and increases in extensigraph extensibility (Ext) due to S fertilization also were observed. None of the observed changes in WI, Rmax, or Ext due to S fertilization significantly affected end‐product quality as measured by loaf volume, crumb grain, and bake score. The nexus between WI and Rmax was weakened by combined N and S fertilization in the first trial, but remained strong in the second trial. Both WI and Rmax increased as N fertilizer and flour nitrogen increased, but at different rates. This observation indicated that by applying N fertilizer to improve dough strength, a disproportionate and disadvantageous increase in WI also resulted, which could be tempered by S fertilization. In this regard, an optimum N:S fertilizer ratio of 3:1 was indicated, although this ratio would be dependent on the balance of available N and S in the soil. Flour N:S ratios <12.5 kept WI to levels desirable in an industrial MDD bakery. Correlations between laboratory WI, mixograph development time (except in the SN1 trial), and farinograph development time were significant. The 125‐g MDD mixers appeared to be more responsive when measuring mixing requirements than the mixograph and farinograph to variations in quality due to environmental and agronomic influences and correlated better with industrial performance.

Link Between Mixing Requirements and Dough Strength

ABSTRACTIndustrial bakeries in Australia and New Zealand using the mechanical dough development (MDD) process have experienced undesirable increases in dough mixing requirements. This problem is an unwanted outcome of breeding programs that have endeavored to increase dough strength as a desirable characteristic. Research was undertaken to determine the nature of the link between dough strength and mixing requirements and its relevance to the MDD process across a wide range of wheat lines. Data from three similar trials of 20 wheat lines confirmed the existence of an apparently tight, positive correlation between mixing requirements and dough strength. Although a wide range in genotypes and environments was used, no significant outliers were found, despite the belief that the link between these quality attributes was breakable or at least flexible. This creates a dilemma, as it would be desirable to reduce work input (WI) for economic reasons but not at the expense of loaf quality, which could have a deleterious effect on product marketability. The resultant nexus between mixing requirements, as measured by MDD WI, and dough strength measured by extensigraph resistance to extension (Rmax), appeared to be influenced by the application of nitrogen fertilizer during cultivation, while the nexus between mixing requirements as measured by mixograph development time (MDT) and Rmax, was influenced by other factors associated with crop location. The nexus between farinograph development time (FDT) and Rmax was affected by both location and nitrogen fertilizer application. The rates of increase in WI, MDT, and FDT against Rmax appeared to differ between high molecular weight glutenin subunits (HMW‐GS) 5+10 or 2+12 (the Glu‐D1 alleles). The Glu‐A1 and Glu‐A3 loci also played a significant role, indicating that by manipulating them it may be possible to shift or manipulate the nexus between mixing requirements and dough strength. Alleles at these loci appeared to be additive in effect on WI, MDT, and FDT, as well as Rmax.

Biscuit-Making Quality Prediction Using Heritability Estimates and Correlations

The aim of this study was to predict biscuit-making quality by using correlations between and, heritabilities of, the most important soft wheat quality characteristics. A full diallele cross was made between six spring wheats. The parents and 30 F, hybrids were used as experimental material. Percentage vitre- ous kernels, breakflour yield, farinograph absorption, farinograph development time and alkaline water retention capacity were highly heritable and were also significantly correlated with sugar-snap biscuit diameter. Selection for these char- acteristics should lead to improvement of biscuit-making quality. In general, softer kernels and a weak dough with a low water absorption were desirable for good biscuit-making quality.

The Effects of Protein Content and Starch Damage on the Physical Dough Properties and Bread-making Quality of Canadian Durum Wheat

Samples of no. 1 and no. 2 Canada Western Amber Durum wheat from two consecutive Canadian Grain Commission harvest surveys were composited according to protein content. The resulting composites were milled to achieve three levels of starch damage. When the standard ICC Alveograph test at constant water addition was performed, the curves became higher and shorter as starch damage increased, owing to the increasing flour water absorption. When alveograph water addition was adjusted, the shape of the Alveograms was almost independent of starch damage. As protein content increased, Alveograph extensibility (length) increased. Starch damage was the predominant factor influencing Farinograph water absorption, development time and stability. Protein content exerted a moderate influence on Farinograph absorption. At low protein content, Farinograph development time and stability decreased as starch damage increased. Depending on protein content, starch damage and baking procedure, durum wheat loaf volume was 65 to 85% of that achieved for a high-quality Canadian bread wheat of comparable protein content. Remix-to-peak baking (long bulk fermentation) performance was influenced positively by protein content and was influenced negatively by starch damage. When baked by the Canadian short process (no bulk fermentation), the negative effects of starch damage on baking performance were not apparent. Bread-crumb properties of all Canadian short-process breads were much better than the corresponding remix-to-peak breads, approaching those of high-quality Canadian bread wheats. When potassium bromate was eliminated from the Canadian short process formula (which includes 37·5 ppm ascorbic acid), no negative effects on bread quality were apparent.

Temperature Variation During Grain Filling and Changes in Wheat-Grain Quality

There have been a few notable occasions when the Australian wheat segregation system (mainly based on specification of variety and protein content) has failed to produce grain which gives dough properties expected for the wheat grade. The reasons for this are likely to relate to growing and storage conditions; of these, variations in temperature during grain filling appear to be a major factor. Observations of crop statistics, field and glasshouse experiments indicate that as growth temperatures increase up to 30°C, there is a general increase in dough strength (as indicated by Extensograph maximum resistance, Rmax, and as Farinograph development time and stability). However, a decline in dough strength is observed following periods of heat stress (e.g. a few days with maxima of over 35°C). Increasing temperatures during grain filling have also been observed to produce grain with a higher protein content, but this observation is not as consistent nor as marked as the effects on dough strength. We have sought to identify genotypes that do not follow this general trend in response to heat stress, and thus could be used as parents to breed for heat tolerance and greater stability of dough quality. A glasshouse experiment involving 45 genotypes has indicated that there is some variation in the response to heat stress, with a few genotypes being promising sources of tolerance. A second important approach to minimising the effects of heat stress is to develop a model to predict grain-quality changes, thus enabling a marketing authority to be forewarned of significant variation from the quality attributes normally expected for a wheat grade, and assisting breeders to better interpret the results of quality testing of lines grown at various sites.

Effect of dextrans of differing molecular weights on the rheology of wheat flour doughs and the quality characteristics of pan and arabic breads

AbstractDextrans (α‐1‐6‐D‐glucans) with weight‐average molecular weights (Mw) ranging from 10 to 500 kDa were used at a rate of 20 g kg−1 (flour basis) in order to modify doughs made from flour of the Australian hard‐grained wheat cultivars Banks, Sunco and Hartog. Doughs containing dextran fractions with Mw below 100 kDa showed significant (P ± 0.01) reductions in Farinograph maximal consistency and significant increases in Farinograph development time. Additions of dextrans also resulted in significant increases in maximal resistance and significant reductions in extensibility when doughs were subjected to Extensograph testing. After addition of dextran fractions with Mw of 100 kDa or less, there were significant reductions in loaf volumes in pan bread of the cultivar Hartog manufactured by a rapid dough system and in pan bread of the cultivars Banks and Hartog made by a fermented dough system. Arabic bread supplemented with dextrans had poorer internal and keeping qualities, and reduced bread surface area, leading to significantly decreased quality scores. These observations are discussed in relation to possible interactions between neutral polysaccharides and other flour components.

The effect of flour properties on the quality of Arabic bread

Thirty-three samples of wheat flour of 80 % extraction were examined for a range of quality factors, and made into Arabic bread, which was then scored for various aspects of quality. Bread scores and results of dough tests were subjected to correlation and regression analysis. These showed that many factors combined to govern bread quality, and that for some individual factors there was a definite optimum. The Farinograph development time and Valorimeter value related well to bread quality, but different flour qualities governed each aspect of bread quality. Baking absorption and starch damage were also important quality parameters. The results show that Arabic bread of optimal quality was produced with flour from hard wheats with protein contents between 10 and 12 %.