Flour constituent interactions and their influence on dough rheology and quality of semi-sweet biscuits: A mixture design approach with reconstituted blends of gluten, water-solubles and starch fractions

The aim of this study was to identify the biochemical parameters that alter the soft wheat flour functionality for biscuit-making quality. A 9-point simplex centroid was used to investigate the effect of varying the ratios of gluten, water-solubles and starch-fractions isolated from three different flour grades (patent, middle-cut and clear flours) which exhibited a wide range of compositional and functionality characteristics on the dough rheological behaviour and the semi-sweet biscuit quality parameters. The amounts of soluble and insoluble proteins and pentosans as well as the endogenous lipids in each flour fraction were quantified. Dough consistency, elongational viscosity, hardness, half-relaxation time, relaxation rate constant, cohesiveness and springiness as well as biscuit density, firmness, tearing force and spatial frequency for the different flour fraction combinations were also assessed. Regression models have been developed to predict the responses of the rheological attributes of the dough as well as the biscuit quality characteristics to the compositional changes of the flour blends; in addition to the main linear terms (concentration of starch, gluten and water-solubles isolated from the different flour grades), significant interaction terms were identified which cannot be neglected in any prediction scheme for the dough and biscuit properties. Contour plots were drawn in an effort to better understand the overall property responses of the dough and biscuits. Significant relationships among certain dough rheological parameters and biscuit characteristics were found, implying a functional role for the total, soluble and insoluble proteins, pentosans and lipids in biscuit making.     

Improvement of dietary fiber content and antioxidant properties in soft dough biscuits with the incorporation of mango peel powder

Consumption of natural bioactive compounds such as polyphenols, carotenoids and dietary fiber offers health benefits including protection against cardiovascular diseases, cancer and other degenerative diseases. Mango peel is a major by-product obtained during processing of mango products such as mango pulp and amchur. Currently, mango peel is discarded which contributes to environmental pollution. In the present study, mango peel was incorporated into biscuits and improvement in the nutraceutical properties of the biscuits was studied. The studies indicated that mango peel contained 51.2% of total dietary fiber, 96 mg GAE/g of polyphenols and 3092 μg/g of carotenoids. Farinograph characteristics of the wheat flour incorporated with mango peel powder (MPP) showed an increase in water absorption from 60 to 68%. Soft dough biscuits were prepared using different levels (5.0, 7.5, 10.0, 15.0 and 20.0%) of MPP and objective, sensory and nutritional properties of the biscuits were evaluated. The total dietary fiber content increased from 6.5 to 20.7% with a high proportion of soluble dietary fiber with incorporation of 20% MPP. The content of polyphenols increased from 0.54 to 4.50 mg/g and carotenoid content increased from 17 to 247 μg/g of biscuit with 20% incorporation of MPP. The biscuits incorporated with mango peel exhibited improved antioxidant properties. Acceptable biscuits with mango flavor were obtained by incorporating 10% MPP. Thus, the results indicated that wheat flour incorporated with MPP yielded dietary fiber enriched biscuits with improved antioxidant properties.     

Predicting hot-press wheat tortilla quality using flour,dough and gluten properties

A cost-effective, faster and efficient way of screening wheat samples suitable for tortilla production is needed. This research aimed to develop prediction models for tortilla quality (diameter, specific volume, color and texture parameters) using grain, flour and dough properties of 16 wheat flours. Another set of 18 samples was used to validate the models. The prediction models were developed using stepwise multiple regression. Dough rheological tests had higher correlations with tortilla quality than grain and flour chemical tests. Mixograph mixing time and dough resistance to extension (from extensibility test using a texture analyzer) were correlated best with tortilla quality, particularly tortilla diameter (r = −0.87 and −0.86 respectively, P < 0.01). Insoluble polymeric proteins (IPP) and gluten index were significantly correlated with tortilla diameter (r = −0.70 and −0.67 respectively, P < 0.01) and specific volume (r = −0.73, P < 0.01). Tortilla diameter was the quality parameter best explained (R² = 0.86) by the prediction models using mixing time and dough resistance to extension. Rheological parameters such as rupture distance and maximum force were also successfully predicted. These prediction models, developed from linear equations, will be an easy and fast tool for breeders to advance or eliminate wheat lines specifically bred for tortilla production.     

Effect of flour type and dough rheological properties on cookie spread measured dynamically during baking

In order to monitor changes that occurred in cookie diameter during baking, a method of calculating cookie diameter was developed using Image Tools software. Cookie images were taken at 30-s intervals during baking using a digital camera. Six biscuit flour types were used in the trial. After the first minutes of baking, a rapid period of expansion started which was significantly different for flour types and finally, after approximately 6th min to the end of baking, cookies showed a slight shrinkage in diameter. A high and significant correlation was found between cookie spread rate and cookie final diameter (r = +0.73, P < 0.001). The technique of lubricated uniaxial compression showed all doughs made from different biscuit flour indicated pseudo-plastic rheological behaviour. However, the measured extensional properties did not correlate with the cookie final diameter.     

Rheological properties and baking performance of rye dough as affected by transglutaminase

Since protein aggregation and formation of a continuous protein matrix in rye dough is very limited, an enzyme-induced protein aggregation method to improve the baking properties was investigated. The effects of microbial transglutaminase (TG) on the properties of rye dough were studied by rheological tests, confocal laser scanning microscopy (CSLM), standard-scale baking tests and crumb texture profile analysis. Addition of TG in the range of 0-4000 Ukg⁻¹ rye flour modified the rheological properties of rye flour dough, resulting in a progressive increase of the complex shear modulus (|G∗|) and in a decrease of the loss factor (tan δ) due to protein cross-linking or aggregation. CLSM image analysis illustrated a TG-induced increase of the size of rye protein complexes. Standard baking tests showed positive effects on loaf volume and crumb texture of rye bread with TG applied up to 500 Ukg⁻¹ rye flour. Higher levels of TG (500 U ≤ TG ≤ 4000 U) had detrimental effects on loaf volume. Increasing TG concentration resulted in an increase of crumb springiness and hardness. In conclusion, the results of this work demonstrated that TG can be used to improve the bread making performance of rye dough by creating a continuous protein network.     

Dough rheology and bread quality of wheat-chickpea flour blends

In this study, partial substitution of wheat flour with chickpea flour at the levels of 10, 20 and 30% was carried out to study their rheological and baking performance. Chickpea flour addition increased the water absorption and dough development time (p < 0.05), while, the extensibility of dough and the resistance to deformation were reduced. Regarding dough stability, it appears that 10% chickpea exhibited higher stability and resistance to mechanical mixing values than the control, while it decreased as the substitute level increases from 20% to 30%. The dough surface of the wheat dough and the blend with 10% was classified as “normal”, however the blend with 20% and 30% produced “sticky” dough surface. The presence of chickpea flour in dough affected bread quality in terms of volume, internal structure and texture. The color of crust and crumb got progressively darker as the level of chickpea flour substitution increased. While the substitution of wheat flour with 10% chickpea flour gave loaves as similar as control.     

Assessment of antioxidant activity and rheological properties of wheat and buckwheat milling fractions

This study examined the antioxidant properties of the ethanolic extracts of wheat milling fractions (wheat flour type 500 and type 850, and bran) and their polyphenol and tocopherol content, and rheological characteristics of wheat dough supplemented with buckwheat flours (light and wholegrain). The results obtained in this study were correlated with our previously published data on wheat flour type 400, wholegrain wheat flour and buckwheat flours.Buckwheat flours exhibited significantly higher (P < 0.05) antiradical activity on hydroxyl (OH), superoxide anion (O₂⁻) and (1,1-diphenyl-2-picrylhydrazyl) DPPH radicals, antioxidant activity and reducing power than all investigated wheat milling fractions when their corresponding IC₅₀ values were compared.The rheological parameters of wheat dough supplemented with light and wholegrain buckwheat flour (0-50%) were obtained by using Mixolab. Results indicated changes in protein and starch properties of dough.The obtained results indicate the benefit of using buckwheat flours in wheat-based food products, i.e. their contribution in functional and tailor-made-food production.     

Modification of the rheological behavior of amaranth (Amaranthus hypochondriacus) dough

For people with celiac disease, a lifelong abdication of gluten including-products is necessary to live a life without celiac affected reactions. The production of high-quality bread from gluten free flour is not simple in comparison to gluten including flours such as those derived from wheat (Triticum spp.). The gas binding and crumb structure forming capacity are very low in gluten free batters. They can efficiently be analyzed through the rheological properties of the dough used. The use of acidification in amaranth (Amaranthus hypochondriacus) dough preparation is a possible means of changing the rheological behavior of amaranth in the desired direction. Methods include the use of lactic acid directly, or the fermentation via lactic acid bacteria. Adding up to 20 mL lactic acid/kg flour in amaranth dough preparation led, during oscillation tests, to an increase of the complex shear modulus up to 30% in the range of 0.1 up to 10 Hz. The use of sourdough fermentation decreased the complex shear modulus in the same test up to nearly 60%. In creep recovery tests, the elastic part of amaranth dough decreased from 65.4% without any treatment down to 63.9% by the addition of up to 20 mL lactic acid/kg flour. Sourdough fermentation by Lactobacillus plantarum was able to decrease it to 54%. The acidification showed a significant positive influence on the rheological parameters of amaranth dough only at the higher stress level. In contrast, sourdough fermentation was able to produce doughs with viscosity and elasticity similar to that found in pure wheat flours.     

Glucose and pyranose oxidase improve bread dough stability

When used in bread dough systems, glucose oxidase (GO) and pyranose oxidase (P₂O) generate H₂O₂ from O₂. We here studied their potential to improve dough and bread characteristics. Neither GO nor P₂O significantly affected the volume of straight dough bread produced with fermentation and proofing times of respectively 90 and 36 min at dosages up to 0.50 nkat/g flour. Supplementation with 1.00 nkat/g flour of GO or P₂O significantly decreased bread loaf volume. The resistance of dough (fermented for 20 min and proofed for 56 min) to an applied shock was substantially improved by inclusion of 0.08, 0.25, 0.50 or 1.00 nkat/g flour of GO or P₂O in the dough recipe. Thus, the proofed doughs showed significantly less collapse and the resultant breads had higher loaf volumes than did the reference breads. Yeast probably exerts an oxidizing effect on dough, which, depending on the exact breadmaking protocol used, might veil the positive oxidizing effect of the enzymes on dough properties during prolonged fermentation.     

Properties of Short-Dough Biscuits in Relation to Structure

The mechanical properties of short-dough biscuits of various composition were determined in three-point bending tests. The temperature during dough preparation and the dough water content affected the air volume fraction and the mechanical properties to an extent which depended on the fat content. These results suggest that the air volume fraction of the biscuits is likely to be related to the rheological properties of the doughs. The temperature at which measurements were made affected the mechanical properties of the biscuits, especially at higher fat contents. The diffusion of Sudan III into the biscuits also depended on the fat content. The mechanical properties were markedly influenced by water content; as a result of the plasticising effect of water, the matrix underwent a glass transition. The effect of sugar type on mechanical properties depended on the type of biscuit. It is concluded that low-fat biscuits are fat-dispersed systems and that high-fat biscuits are bicontinuous. Whether biscuits are in a glassy or rubbery state cannot be predicted from their water contents in relation to the state diagrams of either gluten or sucrose.     

GlutoPeak parameters of whole wheat flours for gluten quality evaluation in soft wheat breeding programs

In soft wheat breeding programs, the gluten strength of flours from specific genotypes is determined by various chemical and rheological tests. Based on such tests, the experimental wheat lines with very weak flour gluten are typically selected for the production of soft-dough biscuits, while the lines with medium gluten strength and extensibility are reserved for hard-dough biscuits. Often, the genotypes having high gluten strength are removed from such breeding programs. In the present study, the usability of the GlutoPeak tester on whole wheat flour samples was investigated for assessing the gluten strength of soft wheat breeding materials. In the study, 25 soft wheat genotypes, grown in seven locations for three years, were categorized by commonly used gluten-quality-related parameters. Based on the results of the study GlutoPeak whole wheat flour PMT values ranging from 30.0 to 50.0 s and AM values from 15.0 to 20.0 GPU were found to be suitable for soft-dough biscuit products, whereas the values between 40.0 and 60.0 s and 20.0 and 23.0 GPU were appropriate for hard-dough biscuit products. The genotypes exhibiting AM values > 24.0 GPU and PMT values > 60.0 s were judged to have too-strong gluten, and thus eliminated from the breeding program. The gluten aggregation energy (AGGEN), and the torque after the maximum torque (PM) values were only useful and applicable to flours for soft-dough products. The maximum torque (BEM) values were not effective in discriminating against the genotypes. The results of this study demonstrated that the GlutoPeak whole wheat PMT and AM parameters can be recommended as quick and accurate parameters especially for early generation screening with small-scale tests in soft wheat improvement programs.     

Wheat flour non-starch polysaccharides and their effect on dough rheological properties

Wheat (Triticum aestivum L.) flour is able to form dough with unique rheological properties that allow bread making. It is well known that wheat protein content affects dough rheological properties, but there is not enough evidence about the role of other minor flour constituents. One such minor constituent is non-starch flour polysaccharides, which are mainly pentosans formed by a xylopyranosyl linear chain branched with arabinofuranosyl residues. Their spatial distribution and branching pattern can affect their relationship with gluten forming proteins and thus influence their functional properties, the dough rheological properties, and thereby the flour baking quality. In this study the content and structural characteristics of non-starch polysaccharides were investigated, as well as their influence on some dough physicochemical parameters. Five different wheat flours samples milled from Uruguayan wheat varieties with diverse rheological and breadmaking properties were used in this study. Water soluble flour polysaccharides were extracted and the amount of pentosans was determined by the orcinol-HCl method. The pentoses composition was determined before and after acidic hydrolysis of the water soluble polysaccharide fractions by GC. No free pentoses were detected in any of the assayed flour samples, so the pentoses composition found in the hydrolyzed samples was attributed to the non-starch water soluble polysaccharides. Water unextractable non-starch polysaccharides were determined by difference between the total and the soluble non-starch polysaccharides flour content.An improved method for the quantification of water extractable and non-extractable non-starch polysaccharides, using baker's yeast, was developed. Using this method, total and soluble non-starch polysaccharides content could reliably be determined both in whole flour and in pentosans enriched fractions. Free monosaccharide content was in the range from 0.03% to 0.06% (w/w), while the arabinose/xylose (Ara/Xyl) ratios varied from 0.8 to 1.4 in soluble non-starch polysaccharides and from 0.7 to 0.9 in total non-starch polysaccharides. The different Ara/Xyl ratios found for water extractable and unextractable arabinoxylans clearly indicates different substitution degrees in the polymers. Analysis of the dough rheological parameters in relation to the water soluble and non-soluble non-starch polysaccharides and the Ara/Xyl ratios from different wheat varieties was performed. A clear relation between some of these parameters could be inferred, since a direct relationship between total unextractable (AXi) content and resistance of dough to extension (P), as well an inverse relationship between the same parameter and dough extensibility (L) were observed. These results suggest that the flour non-starch polysaccharide content, as well the Ara/Xyl ratios may be used as additional parameters to estimate some of the wheat flours dough properties.     

Old and modern durum wheat varieties from Italy and Spain differ in main spike components

Four field experiments comparing 24 durum wheat varieties grown at different periods during the 20th century in Italy and Spain were carried out to assess the changes caused by breeding activities on the number of grains per main spike and its determinants: number of spikelets per spike, number of grains per spikelet, fertile flowering and grain setting. Increases of 0.14 grains spike⁻¹ year⁻¹ (0.43% year⁻¹ in relative terms) and 0.08 grains spike⁻¹ year⁻¹ (0.22% year⁻¹) were observed in Italian and Spanish varieties, respectively. The overall change in the number of grains per spike in Italian germplasm (29.5%) was due to increases in both, the number of spikelets per spike (7.5%) and the number of grains per spikelet (20.3%), while in Spanish varieties the increase in the number of grains per spike (19.5%) was only attributed to the improvement of the number of grains per spikelet. The increase in the number of fertile florets per spike (about 12%) was similar in both countries, but while it explained more than 70% of the changes in the number of grains per spike in Spanish varieties, grain setting was responsible for most of the improvement in the number of grains per spike in the Italian germplasm. The percentage of florets setting grains was 68 and 64% in modern Italian and Spanish varieties, respectively. Most of the changes in the number of grains per spikelet were found in the upper part of the spike on Italian varieties, whilst they were more evenly distributed in the Spanish ones. The main achievement derived from the introduction of the Rht-B1 dwarfing gene was an increase in the number of grains per spikelet, but it did not have any effect on the number of spikelets on the main spike. The lack of genetic associations between grain setting and both the number of spikelets per spike and the number of fertile florets per spike suggests that future yield gains may be obtained through increases in the three components independently.     

Evaluation of CIMMYT conventional and synthetic spring wheat germplasm in rainfed sub-tropical environments. II. Grain yield components and physiological traits

CIMMYT hexaploid spring wheat (Triticum aestivum L.) germplasm has played a global role in assisting wheat improvement. This study evaluated four classes of CIMMYT germplasm (encompassing a total of 273 lines), along with 15 Australian cultivars (Oz lines) for grain yield, yield components and physiological traits in up to 27 environments in Australia's north-eastern region, where terminal drought frequently reduces grain yield and grain size.Broadly-adapted CIMMYT germplasm selected for grain yield had greater yield potential and improved performance under drought stress, being up to 5% greater yielding in High-yielding (mean yield 429 g m⁻²) and 4-10% greater yielding than adapted Oz lines in Low-yielding environments (mean yield 185 g m⁻²). Whilst maintaining statistically similar harvest index and spikes m⁻² compared to broadly-adapted Oz lines across all environments, sets of selected CIMMYT lines had greater canopy temperature depression (0.18-0.27 °C), dry weight stem⁻¹ (0.20-0.37 g), increased grains spike⁻¹ (0.8-3.4 grains), grain number m⁻² (ca. 20-800 grains), and maturity biomass (56-83 g m⁻²). Compared to selected Oz lines, broadly-adapted CIMMYT lines had a smaller reduction in Low compared to High-yielding environments for these traits, especially dry weight stem⁻¹, such that CIMMYT lines had ca. 25% and 10% greater dry weight stem⁻¹ than the Oz lines in Low- and High-yielding environment groups, respectively. Broadly-adapted CIMMYT germplasm also had slightly higher stem water soluble carbohydrate concentration at anthesis (ca. 6 mg g⁻¹), which contributed to their higher grain weight (ca. 0.5 mg grain⁻¹), and maintained an agronomically appropriate time to anthesis and plant height. Thus current CIMMYT germplasm should be useful donor sources of traits to enrich breeding programs targeting variable production environments where there is a high probability of water deficit during grain filling. However, as multiple traits were important, efficient introgression of these traits in breeding programs will be complex.     

Biscuit-making potential of millet/pigeon pea flour blends

Biscuits were produced from millet flour (MF) and pigeon pea flour (PPF) blends. The various ratios of MF to PPF used were 100:0, 75:25, 65:35, and 50:50. The biscuits were analyzed for their nutritional composition. They all contained high proportions of protein (7.5–15.2%), fat (17.1–18.1%) and digestible carbohydrate (60.2–66.5%). The moisture content was in the range 5.0 to 6.6%, ash 1.5–2.3% and crude fiber 0–0.1%. Sensory evaluation results indicated that all the biscuits had high sensory ratings for all the selected attributes evaluated. The recipe with the 65% MF/35% PPF blend resulted in the highest scores for flavor, texture and general acceptability. There was no significant difference (p> 0.05) between all the biscuits and the familiar Nasco short cake biscuit (reference) in flavor, color, texture and general acceptability.     

Comparison of structural features of reconstituted doughs affected by starches from different cereals and other botanical sources

Starch, as the main component of flour products, determines the physicochemical properties of dough. This work investigated the relationship of the physical properties of seven types of starches from various cereals with the structural features of reconstituted dough. Results of mixing and tensile properties analysis and scanning electron microscopy displayed that rice reconstituted flour exhibited maximum water absorption; pea reconstituted flour had higher dough stability; sweet potato dough had higher tensile resistance; highland barley dough had the greatest extensibility. Moisture distribution analysis revealed that various model dough showed remarkably different water distribution, which was distributed at T₂₁ (0.07–0.11 ms), T₂₂ (0.8–2.66 ms) and T₂₃ (10.0–20.82 ms). Correlation analysis indicated that large starch granules associated with good dough stability; amylose content of starch positively affected tensile resistance of dough; crystallinity of starch showed negative effects on water absorption; starch with higher crystallinity associated with greater dough stability.     

Genetical,Biochemical and Technological Parameters Associated with Biscuit Quality. II. Prediction Using Storage Proteins and Quality Characteristics in a Soft Wheat Population

The present research aims to study the genetic, biochemical and technological characteristics of the Portuguese soft wheat landrace «Barbela» population. Several new HMW-GS and ω-gliadins that characterise this population were identified. The potential of this local variety for biscuit production was evaluated using 150 derived pure lines cultivated over three consecutive years. The use of various indirect tests and storage protein analysis allowed us to select 98 lines to study biscuit value (sweet-biscuit). The sweet-biscuit parameters studied were the speed and energy of dough extrusion, cooking time, dough temperature, and biscuit mass before and after cooking, length, thickness, width, density and surface appearance of the biscuit. These parameters were related to the technological characteristics as evaluated by mixograph and alveograph analysis as well as grain hardness, starch damage levels, protein content, relative viscosity of the pentosans, storage protein alleles, Zeleny test, flour yield and thousand kernel weight of grains. As the «Barbela» lines were all of the soft type, our study demonstrated that grain hardness did not significantly influence the parameters of the biscuit test. Multiple regression analysis showed that protein content was the main variable accounting for the quality potential of the soft wheats selected for biscuit value. Protein content was negatively correlated with machinability (the ratio of extrusion speed/energy of dough extrusion), length and surface appearance of the biscuit. Moreover, the relative viscosity of the water-soluble pentosans was important for several biscuit parameters such as surface appearance and extrusion time. The variables of the mixograph generally correlated well with several biscuit parameters. Conversely, alveograph parameters did not show any significant correlation with the biscuit test. The variation observed in «Barbela» lines for extrusion energy, length, density and surface appearance in the biscuit test were significantly influenced by the Glu-1 locus. This study allowed us to define additional criteria for predicting sweet biscuit value in a soft wheat progeny.     

The influence of temperature extremes on some quality and starch characteristics in bread,biscuit and durum wheat

Environmental conditions during grain-fill can affect the duration of protein accumulation and starch deposition, and thus play an important role in grain yield and flour quality of wheat. Two bread-, one durum- and one biscuit wheat were exposed to extreme low (−5.5 °C for 3 h) and high (32 °C/15 °C day/night for three days) temperatures during grain filling under controlled conditions for two consecutive seasons. Flour protein content was increased significantly in one bread wheat, Kariega, under heat stress. Cold stress significantly reduced SDS sedimentation in both bread wheats. Kernel weight and diameter were significantly decreased at both stress treatments for the two bread wheats. Kernel characteristics of the biscuit wheat were thermo stable. Kernel hardness was reduced in the durum wheat for the heat treatment. Durum wheat had consistently low SDS sedimentation values and the bread wheat high values. Across the two seasons, the starch content in one bread wheat was significantly reduced by both high and low temperatures, as is reflected in the reduction of weight and diameter of these kernels. In the durum wheat, only heat caused a significant reduction in starch content, which is again reflected in the reduction of kernel weight and diameter.     

脱脂和重组对面团流变学特性的影响

选用3个筋力不同的小麦品种(系)为材料,采用脱脂面粉、重组面粉和原面粉相比较的方法,研究了小麦脂类对面粉主要基础品质指标、面团拉伸和粘度特性的影响。结果表明:(1)脱脂后面粉沉淀值、降落值下降,面粉白度提高;(2)脱脂后鲁麦14和01-35的面团最大拉伸阻力、拉伸面积和最大拉伸比变大,延伸度变小,但PH3259表现为相反的趋势;(3)与原面粉相比,脱脂后面团粘度变小,附着功减少,粘聚性下降;(4)重组面粉与原面粉面团流变学特性无明显差异。     

Genetical,Biochemical and Technological Parameters Associated with Biscuit Quality. I. Prediction Using Grain Hardness and Water Extractable Arabinoxylans

The aim of this work was to identify the main biochemical and technological parameters that could be efficient in wheat breeding programs for biscuit-making quality. A semi-sweet biscuit was chosen as the standard biscuit for this study. Evaluation of biscuit-making quality was carried out with a set of 39 French cultivars. Thirty-six biochemical and technological characteristics were determined on this plant material. Variables obtained from the biscuit test were closely associated with grain hardness (GHa) and (to a lesser extent) with the viscosity (Visc) of water extractable arabinoxylans in flour. High molecular weight glutenin subunits (HMW-GS) and total proteins were also found to be linked to biscuit quality but had less effect than grain hardness and viscosity. Multiple regression analyses revealed that starch damage was highly correlated with grain hardness and explained 60·1% of variations in consistence, 70·5% in thickness, 76·6% in density and 51·9% of the rupture force of the biscuits. The heritability of ten biscuit-test parameters and ten flour characteristics was evaluated using a set of 19 cultivars grown in three different locations. All the parameters analysed (except surface appearance) were significantly influenced by the genotype, whereas location did not significantly affect machinability, thickness or surface appearance. Starch damage, laser granulometry, grain hardness, density and thickness of the biscuit displayed the highest heritability coefficients, 0·95, 0·94, 0·92, 0·92 and 0·90, respectively. Our results provide reliable information for designing wheat breeding programs to improve biscuit quality. Results also indicate that the creation of wheat cultivars to improve the quality of semi-sweet biscuits can be achieved through breeding programmes.