Studies on the composition,quality and processing of triticale Part 3. Rheological and baking properties

Studies on rheological and baking properties of 14 promising strains of triticale and two check wheat varieties from India are reported. The farinograms obtained from triticale flours, in general, revealed poor dough development time and lower stability than those from wheat flours. The mean water absorption capacity of triticale flours was 54.3 percent compared to 64.4 percent of wheat flour. The triticale flour produced poor loaf volumes with mean value of 399 cm³ compared to 475 cm³ of wheat flour. Cookie baking tests showed that triticale flours were eminently suited for this purpose because of their soft flour and weaker gluten. Triticale whole meal required much less water for preparation of dough for chapatis and produced red coloured chapatis which tended to stale faster.     

Effect of waxy flour blends on dough rheology and bread quality

Although much research has been conducted on wheat flour dough rheology, the principal focus has been the role of the protein fraction. Starch is the main component of flour and plays a key role in dough dynamic properties, particularly during heating. This study assesses the effect of two different waxy flours, a durum and a bread wheat, and their blends with commercial bakers' flour on dough rheology during heating with a concurrent investigation into baking performance. Both waxy flour blends produced similar effects on dough rheological behaviour despite differences in protein content, acting to delay gelatinisation and reduce storage modulus. The main effects in bread were to increase loaf expansion during baking and reduce loaf firmness. It is postulated these effects are largely water mediated, with the higher swelling ability of the waxy starch granules reducing overall water availability and driving complete gelatinisation to higher temperatures.     

A Comparative Study of the Inter-Relationships Between Mixograph Parameters and Bread- Making Qualities of Wheat Flours and Glutens

The mixing characteristics and bread-making qualities of flours, reconstituted flours and glutens from a diverse range of wheat cultivars obtained from Canada, France and the UK, were investigated. Simple correlations were calcu-lated among Mixograph parameters, loaf volume, Glu - 1 quality scores, protein content, SDS-sedimentation volume and baking absorption. The results indicate that the mixing properties of flours from cultivars in the medium–strong range are significantly influenced by their protein contents. On the other hand, the mixing properties of ‘extra strong’ or weak flours are relatively less affected by their protein contents, and it appears that the protein quality primarily controls their behaviour during mixing. Gluten samples, other than weak glutens from cvs Riband and Corin, required a longer time to mix to peak dough resistance (PDR) than their corresponding flour or reconstituted flour samples. However, the differences in mixing time were more pronounced between ‘extra strong’ glutens and their corresponding flours or reconstituted flours. The Mixograph parameter PDR showed highly significant ( P< 0·001) correlations with loaf volume for flour, reconstituted flour and gluten samples. In each case, variation in PDR explained more than 65% of the variation in loaf volume, reaching about 83% for glutens. PDR was also significantly correlated with Glu - 1 quality scores. However, the mixing times for flours, reconstituted flours and glutens demonstrated no simple correlations with loaf volume. On the basis of the results, it appears that the 2 g Mixograph PDR value for flour or gluten may be used to assess flour or gluten bread-making quality. It may be used as a viable alternative to the baking test for the evaluation of the baking potential of flour or gluten, as well as an alternative to currently used ‘gel protein’-based pro-cedures for differentiating between ‘strong’ and ‘extra strong’ wheats.     

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.     

Use of durum residue flour,a lower value product of durum milling,by incorporation into wheat flour dough without deterioration in baking quality

BACKGROUND: During the milling of durum wheat to semolina, about 10–15% of total products produced is residue flour, a lower value product than the semolina. This study investigated the potential for using the durum residue flour as an additive in bread‐making to improve its potential commercial value. RESULTS: Incorporation of residue durum flour from 102 breeding lines into a low protein flour and standard bakers' flour at 20% incorporation improved the bake loaf volume with minimal change in Mixograph dough mixing time and peak resistance in many of the lines tested. Loaf yellow b was always increased even with only a 10% incorporation. Baking flours can tolerate 20% incorporation with no deleterious affects on loaf volume and bake score. CONCLUSION: The results show a potential for using the lower value durum residue flour for baking bread of acceptable quality with a slightly higher yellow colour. This would improve the profitability for the miller and provide alternative ingredients to the baker for preparing specialty breads. Copyright © 2008 Crown in the Right of the State of New South Wales and Society of Chemical Industry     

Effect of flaxseed and wheat flour blends on dough rheology and bread quality

The rheological and baking properties of flaxseed/wheat composite flours were studied. Flaxseed flour was used to replace 50, 100, 150 and 200 g kg^?1 of wheat flour in bread. Farinographic studies showed that water absorption, dough development time and mixing tolerance index increased as the amount of flaxseed flour increased, while dough stability decreased at 100, 150 and 200 g kg^?1 of flaxseed flour substitution. The extensographic energy of dough also decreased at 150 and 200 g kg^?1 flaxseed levels. The addition of increasing amounts of flaxseed flour caused a decrease in extensibility. Doughs containing 100, 150 and 200 g kg^?1 flaxseed flour showed resistance to extension comparable to that of control dough. The specific volume of flaxseed flour breads was similar to that of control bread. Crust L, a, b values of breads with flaxseed flour were lower than those of control bread. Breads with flaxseed flour gave lower crumb L and b values and higher a values than control bread. The sensory properties showed that an acceptable bread could be produced using flaxseed flour up to a level of 200 g kg^?1. Copyright © 2007 Society of Chemical Industry     

Formulating a new high fiber rusk for production on commercial scale

Three formulas were prepared for production of high dietary fiber rusk on production scale. The preparation was based on partial replacement of wheat flour with different levels of wheat bran, barley and maize flours. Chemical composition, dough characteristics, baking performance and sensory evaluation of rusk were investigated. A remarkable improvement in minerals (calcium and phosphorus) and dietary fiber was achieved. Formulas 'A' and 'B' contained about 3 folds dietary fiber and formula 'C' contained about 4 folds compared with control rusk. The rheological properties of the dough were affected by the fiber incorporation in all suggested formulas. Baking performance showed that all rusk formulas were lower in loaf volume and higher in loaf weight than control sample. Physical measurements and sensory characteristics of rusk indicated generally that all formulas were acceptable, but formula B which contains 70 g wheat flour +10 g wheat bran +10 g maize flour +10 g barley flour seems to be generally superior in symmetry of shape, crust and crumb colour, crumb texture, break and shred, aroma and taste.     

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.     

Studies on baking of high alpha-amylase flours: effect of pH,salt and L-cysteine . HCI in the dough

The effect of varying concentrations of sodium chloride (0 to 2.5%), pH (5.8 to 4.2) and KBrO₃ (75 ppm) with and without addition of L-cysteine ± HCI (25 to 75 ppm) on the baking of flours with high content of alphaamylase (108 to 540 SKB/100 g) was compared with a normal flour. Decreasing the pH of dough to 4.2 and increasing the salt concentration to 2.5% reduced the loaf volume and gluten recoveries considerably. Decreased pH also reduced the mixing tolerance of dough, which was counteracted by increased salt content of normal and high alpha-amylase flours. A combination of low pH, salt and L-cysteine ± HCI and 75 ppm of KBrO₃ without sugar in the dough of higher alpha-amylase flour produced a satisfactory loaf by eliminating bulk fermentation.     

Studying the effects of whole-wheat flour on the rheological properties and the quality attributes of whole-wheat saltine cracker using SRC,alveograph, rheometer,and NMR technique

Quality attributes of soft wheat products are affected by physicochemical characteristics and rheological properties of wheat flour. Whole-wheat flour has a significant impact on baking qualities (stack height, stack weight, specific volume, and breaking strength) of whole-wheat saltine crackers due to its high water absorption capacity. SRC profiles, alveograph and rheometer parameters were determined to observe the effect of whole-wheat flour on whole-wheat cracker flour blends. NMR technique was utilized to demonstrate the water migration and competition in whole-wheat dough components. Results of SRC testing revealed that the water absorption of whole-wheat flour blends increased with the addition level of whole-wheat flour. The rheological properties (G′, G″, P, L, W values) were influenced significantly by the presence of whole-wheat flour. Results of NMR indicated that water migrated from gluten network into arabinoxylans matrix in whole-wheat dough system, resulting in inferior saltine cracker-baking qualities of whole-wheat flour, i.e., small breaking strength, stack height and specific volume. The stack height, specific volume, and breaking strength of end products showed significant correlations with the arabinoxylans, dough extensibility, and gluten index of whole-wheat flour.     

Incorporation of germinated mung bean flour with rice flour to enhance physical,nutritional and sensory quality of gluten-free cookies

Quality of the cookies substituted with germinated mung bean flour (GMF) to rice flour (RF) to produce gluten-free cookies were investigated in this study. The GMF was used to formulate with the RF to obtain the composite flours with different total protein contents of 6, 9, 12, 15, 18 and 21 (%, d.b). The increase in the substituted amounts of GMF contributed to the lower baking loss, diameter and spread ratio, but the higher thickness and hardness of the cookies as compared to the RF-based cookie. The cookies with more GMF substitution expressed lower lightness (L*) values, but higher redness (a*) and yellowness (b*) values than the others. The cookies substituted with 60% of the GMF (60-GMFC) exhibited similar baking loss, thickness, diameter, spread ratio and lightness values to the wheat flour (WF)-based cookies. The total amounts of essential amino acids and the sum of histidine, lysine and methionine of the composite flour-based cookies were 3.90% and 1.64%, significantly higher than those of the RF-based cookie (1.93% and 0.66%, respectively) or the WF-based cookie (1.70% and 0.58%, respectively). As a result, healthy gluten-free cookies could be prepared using the RF with the substitution of the germinated mung bean flour.     

Dough characteristics of Irish wheat varieties II. Aeration profile and baking quality

The aeration profile of doughs made from Irish wheat varieties was examined during fermentation. The fermentation process was evaluated with a Chopin rheofermentometer and also by monitoring the dynamic dough density. Minimum dough density which indicates maximum dough expansion was correlated with maximum dough height reached in the rheofermentometer (r = −0.8). Baked loaves from the samples were evaluated for their overall quality. The poor baking potential of one variety (Trappe) as well as the low expansion capacity of another (Raffles) was discriminated from the results obtained from both tests. Loaf volume was correlated with the maximum dough height measured with the rheofermentometer and with the minimum dough density. The overall baking quality of the flours was evaluated by using 3D scatter plots which combined loaf volume with number of cells/mm² and intrinsic hardness. Using this technique, the varieties were divided into clusters depending on their baking quality. Principal Components Analysis was carried out incorporating all the measured dough and bread properties. The loading plot indicated that rheological parameters are those most likely to predict loaf volume whereas other crumb characteristics such as cell size and crumb hardness were difficult to relate to measured dough properties.     

Arabinoxylan content and characterisation throughout the bread‐baking process

End‐use quality of wheat (Triticum aestivum L.) is influenced in a variety of ways by nonstarch polysaccharides, especially arabinoxylan (AX). The objective of this study was to track total and water‐extractable AX (TAX and WEAX, respectively) throughout the bread‐baking process, using wholemeal and refined flour. The TAX and WEAX content and the ratio of arabinose: xylose were assessed in flour, mixed dough, proofed dough and the bread loaf, which was separated into crumb, upper crust and bottom crust. Changes in TAX during the baking process differed between the refined flour and wholemeal samples, suggesting a change in the TAX availability which we ascribe to molecular interactions and heat treatment. WEAX content dramatically decreased during baking, suggesting that oxidative cross‐linkages rendered it unextractable. Higher levels of WEAX and lower levels of arabinose substitution were correlated with higher loaf volumes for refined flour among the hard wheat varieties. Having a better understanding of the importance of both WEAX content and arabinose substitution allows for directed breeding efforts towards improved hard wheat varieties for optimum bread baking.     

The formation and properties of wheat flour doughs

Among the cereal flours, only wheat flour will form a viscoelastic dough when mixed with water. The viscoelasticity appears to be because the gluten proteins are water compatible and thus will swell and interact. The gluten protein's large molecular size and low charge density appear to allow them to interact by both hydrogen and hydrophobic bonds. Wheat flour doughs are also unique in their ability to retain gas. This property appears to result from a slow rate of gas diffusion in the dough. The third major unique property of wheat flour doughs is their ability to set in the oven during baking, and thereby to produce a rigid loaf of bread. Although not clearly understood, this appears to be a heat-induced crosslinking of the gluten proteins.     

Effect of fungal α-amylase on the dough properties and bread quality of wheat flour substituted with polished flours

Whole grains of a hard-type wheat cultivar ‘1CW’ (No. 1 Canada Western Red Spring) were polished from the outer layer to the inner layer by 10% of the total grain weight using a modified rice-polisher. The polished flours of three fractions; C-1, C-5, and C-8 corresponding to 100–90%, 60–50% and 30–0% layer of the 1CW grain, respectively were used in this study. Effects of fungal α-amylase on polished flour substitution for the common wheat flour CW of 1CW on rheological or physicochemical dough properties and bread qualities were studied. When the polished flours were substituted for CW without fungal α-amylase, the mixing tolerance index of dough in a farinograph and all parameters of viscoelastic properties significantly increased rather than those of CW alone. As a result, baking qualities of breads made from the substituted flours were significantly inferior. But, the polished flours increased the total gas generation significantly during fermentation, as compared with CW alone. The addition of fungal α-amylase to polished flour substituted CW distinctly developed gluten matrix in the SEM images and produced large amounts of the generated gas during fermentation. Therefore, the loaf volume and firmness of breads were improved by the combined additions of polished flours and fungal α-amylase. Especially, the C-8 of the innermost fraction was more susceptible to affection of fungal α-amylase among all polished flours, and resulted in improvement of gas cell distribution and softness of breadcrumbs without lowering the loaf volume as compared with CW bread.     

Prediction of wheat quality parameters using near-infrared spectroscopy and artificial neural networks

In wheat and flour processing, the quality control needs quick analytical tools for predicting physical, rheological, and chemical properties. In this study, near infrared reflectance (NIR) spectroscopy combined with artificial neural network (ANN) was used to predict the flour quality parameters that are protein content, moisture content, Zeleny sedimentation, water absorption, dough development time, dough stability time, degree of dough softening, tenacity (P), extensibility (L), P/G, strength, and baking test (loaf volume and loaf weight). A total of 79 flour samples of different wheat varieties grown in different regions of Turkey were chemically analyzed, and the results of both NIR spectrum (400–2,498 nm) and chemical analysis were used to train/test the network by applying various ANN architectures. Prediction of protein, P, P/G, moisture content, Zeleny sedimentation, and water absorption in particular gave a very good accuracy with coefficient of determination (R ²) of 0.952, 0.948, 0.933, 0.920, 0.917, and 0.832, respectively. The results indicate that NIR combined with the ANN can successfully be used to predict the quality parameters of wheat flour.     

Physico-chemical and sensory properties of chips produced using different lupin (Lupinus albus L.) flour formulations and cooking methods

Development of novel snack foods is an important area of research, and different ingredients are being tested to develop and process new formulations. In this study, lupin chips prepared using different formulations (hulled lupin, whole lupin, wheat and corn flours) were cooked using baking and frying, and changes in the sensory and colour parameters, acrylamide contents, fat absorption, peroxide number and p-anisidine values of the final products were studied. Lupin flour significantly changed p-anisidine value of chips. Addition of lupin flour and cooking methods affected the colour, fat absorption and peroxide values. Significant differences in chemical properties of chips made from whole and hulled lupin flours were also observed. Acrylamide was not detected in all the formulations studied. The lupin chips have increased brightness (L*), no acrylamides, reduced peroxide and p-anisidine values and acceptable sensory quality; hence, this ingredient is recommendable for use in snack foods.     

胡芦巴胶对混合粉制面包及生面团品质的影响

去皮高粱粉和粟米粉作面包用粉的替代物，以不同比例添加使用。胡芦巴胶部分替代面粉，替代率可达０．９％，研究了胡芦巴胶对流变特征及面包品质的影响。添加胶越多，生面团吸水量亦越高；添加胡芦巴胶后，生面团的稳定时间、断裂时间和机械耐力指数均有提高。按４∶１的面粉／高粱粉配方，添加０．６％胶可增大面包体积２１．８％，而０．９％的胶添加量能增大面包体积２１．３８％．     

Effect of Amino Acids and Peptides on Mixing and Frozen Dough Properties of Wheat Flour

Free amino acids, peptides, and vital wheat gluten were investigated to determine their effect on the mixing and frozen dough baking properties of wheat flour. Addition of 1% cysteine and aspartic acid decreased and glutamic acid, histidine, arginine, and lysine increased the mixing tolerance of flour. Cystine, methionine, tryptophan, and phenylalanine increased but isoleucine, histidine, glycine, arginine, glutamic acid, aspartic acid, and lysine decreased loaf volume of nonfrozen dough breads. However cystine, methionine, tryptophan, and phenylalanine did not increase loaf volume of bread prepared from frozen dough. Vital wheat gluten increased mixing tolerance and bread loaf volume only for the nonfrozen dough. However, wheat gluten hydrolysate, corn, and bonito peptides decreased mixing tolerance after optimum mixing time and were effective in increasing loaf volume for both frozen and nonfrozen dough. As the amount of corn and bonito peptide increased, specific loaf volumes also increased. Addition of 2.5% corn peptide was most effective in increasing loaf volume of frozen dough bread. Crust browning and crumb stickiness increased, whereas crumb softness decreased with addition of peptides. Addition of less than 1% peptide did not adversely affect the aftertaste and off‐flavor of bread. These results suggest that addition of peptides are effective for improving the baking quality of frozen dough, whereas amino acids and gluten have no effect.     

Functional and multiple end‐use characterisation of Canadian wheat using a reconstituted dough system

Three Canadian wheat cultivars representing the Canada Western Red Spring, Canada Western Extra Strong and Canada Prairie Spring classes, varying in protein content yet containing similar high‐molecular‐weight glutenin subunits, were evaluated for dough functionality and multiple end‐use properties. The effect of protein content on dough properties and end‐product quality was also studied. Gluten, starch and water‐soluble components were extracted from the flours and reconstituted to make up three samples for each variety to match the protein content of the three parent flours. Empirical and dynamic dough rheological properties, baking (bread and tortilla) performance and noodle‐making properties of the flours were determined using small‐scale techniques. Results indicated that protein content had a significant effect on rheological and end‐use quality of wheat flours. Increase in protein content (of the reconstituted dough) increased mixograph peak height (r = 0.761), peak width, maximum resistance to extension and end‐product quality characteristics such as loaf volume (r = 0.906), noodle firmness and cutting force and decreased storage and loss moduli. Reconstituted flours from the three varieties at the same protein content also showed significant differences in mixing time, mixograph peak height, maximum resistance to extension, composite fineness of pan bread, tortilla diameter, cooked noodle hardness, gumminess and dynamic viscosity of dough. This study indicates that a simple reconstituted dough system can provide an unambiguous assignment of the quantitative and qualitative effects of dough components on dough properties. It has the advantages that any aspect of flour composition can be manipulated and details of the relation between composition and functional behaviour can be obtained for any end‐product. Copyright © 2003 Crown in the right of Canada. Published by Society of Chemical Industry