Formulation optimisation of vegetable flour–loaded functional bread. Part II: effect of the flour hydration on the bread quality

In this work, the hydration process of durum wheat–based functional bread loaded with yellow pepper flour was optimised. In particular, the investigated vegetable flour and durum wheat semolina were mixed after they were separately hydrated. Three different amounts of water added to the yellow pepper flour were studied for assessing the effect of vegetable flour hydration level on the dough development and overall quality of bread. The bread formulation investigated in a previous work, based on 25% of yellow pepper and 2% of guar seed as structuring agent where the vegetable flour was directly added to the hydrated durum wheat semolina dough, was chosen as control sample. Results highlighted that dough samples with yellow pepper flour hydrated at highest water content showed a rheological behaviour similar to the durum wheat dough. Moreover, creep analysis showed that the sample added with no‐hydrated yellow pepper flour recorded the greatest resistance to deformation. Same results were obtained for the dough tensile and bread compression tests. The use of the hydrated yellow pepper flour also improved all sensorial attributes.     

Hearth bread baking quality of durum wheat varying in protein composition and physical dough properties

Thirty durum wheat genotypes from ten countries of origin were grown in field plots for two consecutive years. Three of the genotypes were γ‐gliadin 42 types and the remainder were γ‐gliadin 45 types. Among the γ‐gliadin 45 types, six high‐molecular‐weight glutenin subunit (HMW‐GS) patterns were identified: 6 + 8, 7 + 8, 7 + 16, 14 + 15, 20 and 2*, 20. All the γ‐gliadin 42 genotypes contained low amounts of unextractable polymeric protein (UPP) and exhibited low gluten index values and weak gluten properties. The γ‐gliadin 45 genotypes exhibited a wide range of UPP, gluten index and dough strength. HMW‐GS 20 genotypes were generally weak, whereas HMW‐GS 6 + 8 and 7 + 8 genotypes were generally strong. When baked by a lean formulation, long‐fermentation straight‐dough hearth bread process, the durum wheat genotypes exhibited a wide range of baking quality. Loaf volume and bread attributes were strongly correlated with UPP and gluten index. Some of the genotypes exhibited bread attributes and loaf volume equal or slightly superior to those of a high‐quality bread wheat flour. However, even the strongest durum wheat genotypes exhibited inferior fermentation tolerance to the bread wheat flour, as seen by a requirement for lower baking absorption during dough handling and more fragile dough properties when entering the oven. Among the HMW‐GS groups, HMW‐GS 7 + 8 and 6 + 8 exhibited the best and HMW‐GS 20 the poorest baking quality. Farinograph, alveograph and small‐scale extensigraph properties demonstrated that a combination of dough elasticity and extensibility was needed for superior durum wheat baking performance. Copyright © 2007 Society of Chemical Industry     

Spaghetti cooking quality of waxy and non‐waxy durum wheats and blends

Quality attributes of waxy durum wheat (Triticum turgidum L), milled semolina and cooked spaghetti were examined and compared with those of two non‐waxy durum cultivars. With the exception of kernel hardness, wheat quality characteristics were similar for both waxy and non‐waxy durum. Compared with average values obtained for durum wheat grown in North Dakota (USA) during the crop year 2000, the values obtained for the wheat used in this study were equal or better for most parameters evaluated. Semolina extraction for all samples was lower than the 2000 average of 62.6%. The waxy lines had higher ash, lower speck count, similar protein quantity, lower wet gluten and stronger mixograph curves than the non‐waxy cultivars. Waxy durum semolina had higher lipid content, starch damage, stirring number and flour swelling values. Spaghetti made from waxy durum semolina had shorter cooking time, similar cooking loss and cooked weight and lower firmness values, which would be unacceptable by most standards. Spaghetti made from blends containing 20–80% waxy durum semolina were evaluated. Cooking time and firmness decreased and cooking loss increased as the amount of waxy semolina increased. Acceptable spaghetti was obtained using 20–40% waxy semolina blends, depending on the quality of the non‐waxy blending material. Copyright © 2004 Society of Chemical Industry     

Dough properties and baking characteristics of white bread,as affected by addition of raw,germinated and toasted pea flour

Thermal and non-thermal processing may alter the structure and improve the techno-functional properties of pulses and pulse flours, increasing their range of applications in protein-enhanced foods. The effects of germination and toasting of yellow peas (Pisum sativum) on flour and dough characteristics were investigated. Wheat flour was substituted with raw, germinated and toasted pea flour (30%). The resulting bread-baking properties were assessed. Toasting increased dough water absorption and improved dough stability compared with germinated and raw pea flour (p < 0.05). This resulted in bread loaves with comparable specific volume and loaf density to that of a wheat flour control. Significant correlations between dough rheological properties and loaf characteristics were observed. Addition of pea flours increased the protein content of the breads from 8.4% in the control white bread, to 10.1–10.8% (p < 0.001). Toasting demonstrated the potential to improve the techno-functional properties of pea flour. Results highlight the potential application of pea flour in bread-making to increase the protein content.     

Changes in durum wheat kernel and pasta proteins induced by toasting and drying processes

Durum wheat kernels were subjected to a toasting process and the proteins characterised by size exclusion-high performance liquid chromatography (SE-HPLC) and sodium dodecyl sulphate–polyacrylamide gel electrophoresis. With this physical process, albumins and globulins, as well as glutenins and gliadins, polymerised as seen by a shift of the SE-HPLC profile to lower elution times. The polymerisation seemed to happen mainly through disulphide bonds, even though the participation of ω-gliadins to the aggregation suggested the involvement of other kinds of interactions. It led to the revelation of a new peak originated by thermal aggregation of small polymeric proteins. The changes in the chromatographic profile were accompanied by increasing amounts of total unextractable polymeric proteins. The replacement of semolina with toasted durum wheat flour (5%, 10%, 15%, 20% and 30%) for the production of pasta in the shape of spaghetti significantly (p < 0.001) affected the molecular size distribution of the polymeric proteins, even though the replacement of semolina with 5% and 10% of toasted durum wheat flour (TDWF) did not significantly (p > 0.05) change the unextractable polymeric proteins (UPP) when compared with spaghetti made with 100% durum semolina. On the other hand, the replacements of semolina with 15–30% TDWF showed significant (p < 0.001) increase in UPP when compared with 100% durum semolina spaghetti.     

A survey of water‐extractable arabinopolymers in bread and durum wheat and the effect of water‐extractable arabinoxylan on durum dough rheology and spaghetti cooking quality

BACKGROUND: Information on the variation in water‐extractable arabinopolymers (WEAP) in durum wheat and their impact on pasta quality is limited. A survey of the content of WEAP in selected bread wheat varieties and durum wheat was conducted and the influence of water‐extractable arabinoxylans (WEAX) on dough and spaghetti quality was examined by fortifying low‐WEAP durum semolina with purified WEAX. RESULTS: Bread wheat typically possessed higher levels of WEAP than durum wheat, but the latter had a greater range. Purified WEAX was extracted from bread wheat cultivar Sunlin which possessed a high level of WEAP. The extract was used to fortify semolina (0.125–2% w/w) derived from durum wheat variety Tamaroi (low WEAP). Fortification caused a near linear increase in farinograph water absorption of approximately 12% over the range of addition, leading to dough weakening. Reduced cooked pasta stickiness was observed at all levels of WEAX addition. CONCLUSION: Increased WEAX content may be a means to improve pasta quality by reducing pasta stickiness. Durum wheat showed a wide range of WEAP contents, and this may well be exploited by developing cultivars with elevated WEAP levels. © 2008 Crown in the Right of the State of New South Wales and Society of Chemical Industry.     

Effect of Rice, Corn and Soy Flour Addition on Characteristics of Bread Produced from Different Wheat Cultivars

Preparation and consumption of bread enriched with flours that contain appreciable amounts of protein, lysine, dietary fiber, and minerals will provide a healthy alternative to consumers and also a lowering of bread making cost in countries where wheat is not a major domestic crop. Addition of rice, corn, and soy flour to bread and durum wheat flours at 10, 20, 30, 40, 50% levels was carried out to examine the effects on the baking (specific volume, color, firmness) and sensory characteristics of bread. Dough rheological properties were also studied using Brabender Farinograph and Extensograph. Results of the present study suggest that incorporation of rice, corn, and soy in bread wheat flour up to a level of 10% (flour basis) and in durum wheat flour up to 20% produces bread without any negative effect in quality attributes such as color, hardness, and flavor and reasonable acceptance offering promising nutritious and healthy alternative to consumers. Increasing levels of substitution (30 and 50%) resulted in decreasing dough strength, extensibility, and loaf volume, due to the replacement of gluten by the added protein. Overall acceptability scores of these breads were found to be very low. The durum flour can be substituted with nongluten flours up to 10% more than the bread wheat flour because of its stronger gluten matrix and better dough rheological characteristics.     

Formulation optimisation of vegetable flour‐loaded functional bread Part I: screening of vegetable flours and structuring agents

The aim of this work was to optimise durum wheat‐based functional bread loaded with vegetable flours. In particular, the screening of vegetable flours and structuring agents was performed. The per cent sensorial attributes change with respect to the durum wheat bread was calculated. Taste and appearance were the parameters that have most influenced the overall quality of the final product. In the Step 1, yellow pepper flour was chosen because of its taste highly pleasant. In fact, the per cent sensorial attributes change for this sample was about 6%. In the Step 2, different structuring agents were tested to improve the organoleptic properties of the investigated functional bread enriched with 25% of yellow pepper flour. The highest amount of vegetable flour added to the bread results in a low loaf volume, stickiness and compact crumb. A slight improvement compared with the bread sample without structuring agents was observed with 2% of guar seed flour from the appearance and crumb firmness point of view. Therefore, a further optimisation of the functional bread investigated in this work is necessary.     

Physicochemical and sensory properties of soy bread made with germinated,steamed, and roasted soy flour

For the development of healthful gluten-free soy bread acceptable to consumers, we evaluated the effects of various processing procedures for soy flour on bread quality, in terms of beany flavour and texture. We pretreated soy flour by both non-heating (raw:NS and germinated:GS) and heating (steamed:SS and roasted:RS) methods. In addition, to improve the loaf volume, we added 1% hydroxypropyl-methylcellulose (HPMC) to RS flour. Lipoxygenase activity was retained in the non-heat-treated flours (279 U/g for NS and 255 U/g for GS), but was significantly reduced in the heat-treated flours (106 U/g for SS and 69 U/g for RS). Moreover, heat-treated flour had higher isoflavone and ferric reducing antioxidant power than had non-heat-treated flour. However, RS flour had the lowest moisture content and lowest L^∗ value. The GS bread had the highest specific loaf volume (3.53 cm³/g), followed by NS (2.96 cm³/g), RS (2.25 cm³/g), and SS (1.81 cm³/g) bread. GS bread had the lowest hardness (1.53 N), followed by NS (1.65 N), RS (2.00 N), and SS (3.75 N) bread. The addition of 1% HPMC to RS increased the loaf volume (2.44 cm³/g), but decreased the bread’s hardness (1.80 N). As to the sensory properties, the bread with heat-treated flour was perceived to have a less beany odour and taste than was the bread with non-heat-treated flour. However, the latter had a better appearance than the former. These results indicated that soy flour pretreatment could enhance the loaf volume and reduce the beany flavour of whole soy bread.     

Effect of green plantain flour addition to gluten‐free bread on functional bread properties and resistant starch content

Green plantain flour (GPF) was used as a functional ingredient to produce gluten‐free (GF) bread based on a flour blend of rice flour and GF wheat starch (50:50) to improve their functional properties and to increase their resistant starch (RS) content. In pretrials, an addition of up to 30% GPF provided acceptable bread quality with maximum RS content. Based on these trials, two 2³ factorial screening experimental designs were applied, where water content, baking temperature and baking time of GF bread containing 30% GPF addition were optimised. The best baking conditions to achieve satisfying GF bread quality – higher loaf volume, softer crumb firmness and regular porosity structure at the highest RS content could be defined to a maximum addition of water at 160%, baking temperature of 180 °C and baking time of 90 min. The incorporation of GPF showed good potential to improve the quality of GF bread.     

The effect of enzymic modification on the foaming, water absorption and baking quality of defatted soya flour

Defatted soya flour slurries were treated for 0,5,10,15 and 30 min with papain at 50°C and tested for whipability, water absorption and baking quality at replacement levels in wheat flour of 10,20 and 30% (w/w). When whipped, all modified suspensions showed volume increases exceeding 250% with lower stability ratings than the unmodified samples. The 30 min enzyme treated product exhibited excellent water absorption. Use in bread resulted in a depression of loaf volume, development of a granular texture, off-colour and flavour. As was expected, all favourable characteristics decreased upon increasing the percentage of soya product in the dough formulation. Loaf volumes of breads containing 10% modified soya flour (MSF) ranged from 444 to 527 cc; with 20% MSF between 374 and 428 cc, and with 30% MSF between 383 and 409 cc. Loaf volume of all wheat flour bread was 861cc. Hunter colour difference meter readings indicated samples at all replacement levels, regardless of the enzyme modification time, exhibited higher levels of visual lightness than all wheat flour bread. All experimental breads exhibited a higher level of yellow tones and lower level of green tones compared to the all wheat flour bread.     

Effect of flour blending on functional, baking and organoleptic characteristics of bread

Soybean (full‐fat and defatted) and barley flours were incorporated into wheat flour at 5, 10, 15 and 20% substitution levels. The gluten content, sedimentation value and water absorption capacity of the flour blends and the mixing time of the dough decreased with increase in the level of soybean and barley flour separately and in combinations. Protein and glutelin contents increased significantly on blending of soyflour (full‐fat and defatted) to bread wheat flour. The breads prepared from the blends also varied in their loaf weight, loaf volume and sensory characteristics. The bread volume decreased with increasing amount of non‐wheat flour substitution. The crumb colour changed from creamish white to dull brown and a gradual hardening of crumb texture was observed as the addition of soybean (full‐fat and defatted) and barley flours increased. At the higher levels, the acceptability declined because of the compact texture of the crumb and the strong flavour of the product. The addition of 10% of soyflour (full‐fat and defatted) or 15% of barley flour, full‐fat soy + barley or defatted soy + barley flour to bread flour produced acceptable bread.     

BREAD MAKING OF DURUM WHEAT WITH CHICKPEA SOURDOUGH OR COMPRESSED BAKER'S YEAST

Two ways of improving durum wheat bread-making quality were evaluated.
First, durum wheat (cultivar "Papadakis") was blended with bread wheat flour of good (A-flour) or medium (B-flour) quality (70% durum and 30% bread wheat flour). Durum wheat flour displayed the γ-gliadin 45 electrophoretic band and acceptable bread-making quality. Breads from flour blends had better volume, particularly the durum and A-flour blend. The addition of ascorbic and citric acid and malt flour improved dough rheological properties and thus bread volume, as well as staling rate and sensory characteristics. These were more pronounced in the blend of durum with B-flour.
Second, durum wheat flour alone was used to prepare chickpea sourdough-leavened bread, as flavor is important for consumer acceptance. With the addition only of salt, the chickpea sourdough-leavened durum wheat bread displayed acceptable loaf volume, distinguished flavor and longer shelf life compared with bread prepared with compressed baker's yeast.

PRACTICAL APPLICATIONS

One of the practical applications of this study is the possibility of using a common durum wheat cultivar instead of local varieties as is the case with traditional breads. Results of this work may be useful for promoting greater acceptance of durum wheat breads as well as expansion of the use of a traditional Mediterranean chickpea sourdough-leavened durum wheat bread with distinguished flavor and taste.
This work may serve as a guide for determining the quality of flours suitable for production of "home made" or "village" bread (which has high market value as specialty bread) by blending durum and bread wheat flours. Best results are obtained with good-quality bread wheat flour, regardless of the good quality of durum wheat cultivar used, together with the use of the dough improvers implemented in this work.     

Effect of the lentil flour and hydrocolloids on baking characteristics of wholemeal durum wheat bread

In this study, the characterisation of functional bread based on wholemeal durum wheat flour enriched with lentil flour was investigated to find a good balance between the nutritional and organoleptic properties of the final product. In particular, the effect of different percentage of lentil flour (10%, 20% and 25%) and the type and amount of structuring agents (carboxymethyl cellulose, guar seed flour, pectin and tapioca starch) were studied by assessing the sensorial, textural and nutritional properties of the functional bread. Results showed that the increase in the lentil flour at 20% and 25% negatively affected the dough texture and the sensorial quality of the bread. The screening of different hydrocolloids on the bread sample enriched with 25% of legume flour highlighted that the guar seed flour at concentration of 2% allowed obtaining the best results in terms of sensory properties. The nutritional analysis of the optimised functional bread showed an increase in proteins and dietary fibre (total, soluble and insoluble), suggesting its high functional value and the possibility to propose it on a market that is constantly changing and attentive to health benefit of foods.     

The effects of extruded black rice flour on rheological and structural properties of wheat-based dough and bread quality

Addition of raw black rice flour leads to deficient processability on bread making quality. One of the effective methods to modify the functional properties of black rice flour (BRF) composite dough is to extrude black rice flour (EBRF) before incorporation. This study investigated and compared the effect of BRF and EBRF addition level of 10%–50% on the rheology, microstructure of dough and bread quality. The rheological properties of composite dough were recorded by Mixolab, stress relaxation and tensile test. The substitution of EBRF presented higher water absorption but lower development time, protein weakening, starch gelatinization, starch gel stability and starch retrogradation than wheat flour dough. Both the BRF and EBRF dough presented solid-like behaviour, while the EBRF dough showed more viscous, higher resistance and extensibility than BRF dough. The dough microstructure of dough was observed by SEM, and a more compact structure of EBRF dough could be seen than BRF dough. The incorporation of EBRF in bread quality presented higher specific volume, lower bake loss and firmness than BRF bread. These findings indicated the potential utilisation value of extruded black rice flour in bread making.     

Optimising process for making pasta from maize in admixture with durum wheat

Processing conditions for making pasta from blends of maize (Zea mays L) flour and durum wheat (Triticum durum Desf) semolina (ratio 66:33 w) were studied. The maize mill stream characteristics determined the quality of the maize pasta; flours with low lipid content and very fine granulometry produced pasta with good colour characteristics and high cooking quality (with especially good surface conditions). The use of white maize varieties was preferred; they produced pasta which, after heat treatment, had colour indices close to those of durum wheat pasta. Extrusion conditions affected the colour characteristics and cooking quality of the pasta. The cooking qualities of macaroni products were better than those of spaghetti. In all cases, heat treatment (90°C for 2 h) improved the cooking quality of the pasta: it reduced cooking losses but did not alter the surface condition and viscoelasticity index.     

板栗淀粉、蛋白质及全粉的特性及在面包中应用研究

基于淀粉和蛋白质对面包品质至关重要,分析板栗粉、板栗淀粉及板栗蛋白的特性,并探索对面包品质的影响。板栗粉中淀粉（52.87%）、蛋白质（6.58%）均低于高筋小麦粉。与小麦淀粉相比,板栗淀粉更易溶胀、糊化,但热稳定性较差。与小麦蛋白相比,板栗蛋白的α-螺旋含量(10.6%)较低,无规卷曲（34.4%）较高。这些特性正好反映了,随着板栗粉的添加量提高,板栗粉-小麦粉混合粉粉质品质和面包比容均呈下降趋势。当板栗粉添加量为10%时,面包体积最大、气孔细密、评分最佳。     

Qualities and antioxidant properties of bread as affected by the incorporation of yam flour in the formulation

Yams (the tubers of Dioscorea spp.) are widely consumed but are also regarded as a medicinal food in China. Traditional Chinese herbal medicines using yams are only available on a seasonal basis, as yams quickly deteriorate during winter storage. Yam (Dioscorea purpurea, a major variety of yams in Taiwan) was freeze‐dried and ground to obtain yam flour. Bread was made by replacing up to 25% of wheat flour with yam flour. Although the loaf volume decreased with the addition of yam flour, the results showed that up to 20% of yam flour could be included in bread formulation without altering the sensory acceptance of the blended bread. The incorporation of yam flour in bread markedly increased the antioxidant capacity of the bread as tested by both DPPH free radical scavenging and total antioxidation tests. Breads containing yam flour can broaden the utilization of yams and may be regarded as possible health‐promoting foods.     

The effect of emulsifiers,sugar, shortening and soya flour on the staling of barbari flat bread

A standard method has been developed to bake barbari flat-type bread. Instron was used to measure the hardness of the crumb of bread samples as a criterion of staling. Different combinations of emulsifiers, sugar, shortening and soya flour were added to the formula of barbari bread to find their effect on the retardation of hardness. Addition of soya flour increased the loaf weight but decreased its total organoleptic score. Added amounts of different additives tried in this experiment improved the hardness approximately to the same level. The best result was obtained by the addition of sodium stearoyl-2-lactylate and shortening.     

Effects of bread making methods,lupin variety and gluten powder on the quality of bread enriched with high percentage of lupin flour

Lupin is an economical source of protein, fibre and bioactive compounds, and to obtain these health and nutritional benefits lupin flour has been used in bread production. However, addition of more than 10% lupin flour markedly reduces bread quality mainly due to gluten dilution. The main aim of this research was to retain lupin bread quality enriched with higher percentages of lupin flour (20%) by addition of vital gluten powder (0%, 2%, 3.5% and 5%), investigating the effects of lupin variety (Lupinus albus and L. angustifolius) and two baking systems (rapid and sponge & dough). Impact on bread staling qualities was also determined through texture analysis of samples over a 72-h storage period. Compared to lupin bread with nil gluten addition, significant improvements in loaf volume and crumb texture were observed with addition of gluten powder especially at 5% which increased loaf volume by an average of 20% across lupin sources and baking methods, and crumb softness by 30–50%. Differences were observed between the lupin flour sources. L. angustifolius had a reduced weakening effect when blended with the base flour compared with L. albus. The Sponge & Dough process was found to be more suitable to the inclusion of lupin flour than the rapid process.