Effect of Flour Quality, Ascorbic Acid, and DATEM on Dough Rheological Parameters and Hearth Loaves Characteristics

ABSTRACT: The effects of protein quality, protein content, ascorbic acid, diacetyl tartaric acid ester of monoglyc-erides (DATEM), and their interactions on dough rheology and hearth bread properties were studied by size-exclusion fast protein liquid chromatography, Kieffer Dough & Gluten Extensibility Rig, and small-scale baking of hearth loaves. The effect of protein content was either positive or negative on hearth loaf characteristics, form ratio, and area, depending on the amount of the largest glutenin polymers in the flour. Ascorbic acid brought out the potential in the wheat flour known as protein quality. Ascorbic acid and DATEM strengthened the doughs and improved hearth bread characteristics.     

Effects of Protein Size Distribution and Dough Rheology on Hearth Bread Characteristics Baked at Different Processes and Scales

ABSTRACT: The present study investigates the effect of flour and dough characteristics on the baking performance of hearth loaves, which are proved and baked without a tin. A number of experiments were performed at different scales. The most significant and consistent observation was a positive relationship between the protein quality and the form ratio of the loaves (height/width), in which the protein quality was evaluated by both large and small strain rheology, as well as by size distribution of the gluten proteins and other protein quality parameters. The volume of hearth loaves and the slice area are complex characteristics because they are combined functions of loaf height and loaf width; the loaf height was positively related to protein quality, whereas loaf width was negatively related. The total effect of this is not obvious. In general, the loaf volume is more strongly related to the loaf width than is the slice area. For the present material, differences in protein quality were not manifested as significant differences in loaf volume, whereas the slice area was positively correlated to the protein quality. The results obtained at different scales of the baking experiment agreed well with each other.     

Rheological properties of sheeted wheat flour dough measured with large deformations

Abstract

Large deformation rheological properties of a bread dough sheet were compared with baking quality of dough from the same sheet. Both rheological test and baking test could differentiate between dough made from a strong and a weak flour. Apparent viscosity at large deformation appeared to be the best predictor of the minimum sheeting requirement to obtain high loaf volume. This is similar to Mechanical Dough Development (MDD) mixing of dough where the mixing curve (apparent viscosity) is used to determine mixing requirement. Baking tests showed that loaf quality (volume and crumb texture) for bread made with sheeting was different from bread made with MDD mixing, particularly when dough was developed beyond the minimum sheeting requirement. These differences indicate that dough development (or over‐development) by sheeting may occur through a different mechanism than by MDD mixing.     

Dough and Hearth Bread Characteristics Influenced by Protein Composition, Protein Content, DATEM, and Their Interactions

ABSTRACT: The effects of protein composition, protein content, diacetyl tartaric acid ester of monoglycerides (DATEM), and their interaction on dough and bread characteristics were studied by small- and pilot-scale hearth bread baking, dough rheological testing using the Kieffer extensibility rig, and size distribution of proteins. Protein composition had the largest influence on dough and bread characteristics. There was interaction effect between protein quality and protein content on dough behavior. High percentage of sodium dodecyl sulfate-unextractable polymeric proteins in flours gave large area and good form ratio. Increased ratio between monomeric and polymeric proteins resulted in decreased form ratio. Addition of DATEM altered the rheological behavior of the dough and the bread-making performance. The effect was, however, small compared with the effect of the protein composition.     

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.     

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     

INFLUENCES OF THE PROPORTION OF SOLID FAT IN A SHORTENING ON LOAF VOLUME AND STALING OF BREAD

Fats and oils are an important component of bread. Fats and oils are added to improve the properties of a loaf of bread, such as increasing loaf volume and increasing the time before staling is initiated. The physical form of the added fat can affect the overall dough behavior. The effect of hydrogenated soybean oil concentration in an emulsion used for the baking of bread was studied. It was observed that increasing concentration of hydrogenated soybean oil (solid fat) while keeping total lipid content constant led to increased loaf volume and decreased loaf weight. Also, increasing solid fat content led to a reduction in the rate of staling.     

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.     

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     

Effects of cultivar and soil fertility on grain protein yield,grain protein content,flour yield and breadmaking quality of wheat

Grain protein content affects the flour yield and breadmaking characteristics of wheat (Triticum aestivum L). In this study, grain protein yield, grain protein content, flour yield and loaf volume were quantified for four wheat cultivars (Inia, Carina, Kariega and SST 86) grown under six different soil fertility regimes in a long-term fertilisation and irrigation experiment at the University of Pretoria. The experimental design was a randomised complete block replicated four times, with fertility as the main plots and cultivars as the subplot treatments. Grain protein yield, flour yield, loaf volume and mixograph dough peak mixing time varied among cultivars and soil fertility situations. Grain protein content differed among cultivars, but mixograph water absorption and dough characteristics did not differ. The highest grain protein yield was 873 kg ha⁻¹ for Carina and the lowest 527 kg ha⁻¹ for SST 86. Grain protein content averaged 131 g kg⁻¹ for Carina and 122 g kg⁻¹ for Kariega. Breadmaking performance showed that in a well-balanced soil fertility situation, Kariega produced 1025 cm³ of loaf volume while Inia averaged 950 cm³. Grain protein yield increased with increasing soil fertility, but grain protein content, flour yield, loaf volume, water absorption and mixograph peak mixing time varied with soil fertility. The interaction between cultivar and soil fertility was significant for grain protein yield, grain protein content, flour yield, loaf volume and water absorption but not dough peak mixing time. The results indicate cultivar differences in breadmaking quality characteristics and that soil fertility status affects grain protein yield, grain protein content, flour yield, loaf volume potential and water absorption but not mixograph peak mixing time and dough characteristics. © 1999 Society of Chemical Industry     

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.     

The Influence of Environment on Starch Content and Amylose to Amylopectin Ratio in Wheat

There is evidence that starch content plays an active role in determining dough rheological characteristics. The aim of this study was to determine the influence of environment on starch content and amylose: amylopectin ratio, and how this affects breadmaking quality. Ten hard red spring wheat cultivars were planted in three different environments in a randomized complete block design with three replications. Total starch content, amylose: amylopectin ratio, milling, rheological and baking characteristics were measured. Starch content was significantly influenced by the environment. It was significantly negatively correlated with loaf volume, wet gluten content and flour protein content across the three environments. Starch content and protein content were significantly negatively correlated, yet the value was relatively small (r = −0.4) and the relationship was therefore not directly inverse, and other factors influenced this relationship. Some cultivars interacted with specific environments, and they ranked high for starch content and loaf volume. Amylose: amylopectin ratio was very consistent for the three environments but was not significantly correlated with breadmaking quality characteristics across the environments, although there were significant correlations at individual environments. Cultivar choice and environment where cultivars are planted will therefore affect the starch content. High starch content will not necessarily lead to poor baking quality.     

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.     

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。     

Effect of Different Raisin Juice Preparations on Selected Properties of Gluten-Free Bread

Incorporation of sucrose and raisin juice (in concentrated or in dried form) at 3 and 5% of flour weight to commercial wheat starch (Codex Alimentarius) gluten-free flour was carried out to examine the effects on baking, textural, and sensory properties of bread. Breads made with gluten-free flour are usually characterized by poor color and baking characteristics, as well as short shelf life. The current study was conducted to help solve these problems by using raisin juice, a natural sweetener that contains no preservatives, has lower caloric content than sucrose, and includes a number of important vitamins and minerals that are very important for the coeliac disease patients. The study showed that 3% raisin juice in concentrated form contributes to a great improvement in loaf volume, color, and hardness characteristics of gluten-free bread during the first day after baking but a higher staling rate because of its high moisture content. Dried raisin juice gave bread higher loaf volume and better color compared to the control gluten-free bread and also increased its shelf life because of its moisture absorption properties. Sensory analysis revealed a preference for breads containing concentrated raisin juice because of its fruity flavor, whereas all the samples that contained 5% raisin juice had very dark color.     

Effect of Process Modifications in Two Cycles of Dough Mixing on Physical Properties of Wheat Bread Baked from Weak Flour

Common availability of dough improvers permits the production of bread of good quality, but only modifications of the process may be used for the production of natural products. Dough from weak flour, after application of certain treatments, displays poorer baking properties; therefore, in our study, it is proposed to apply slow-speed mixing in two cycles. In the literature, there is a lack of comparisons of results of baking with the straight dough method (one-cycle mixing) with modified methods including the application of two equal cycles of dough mixing and two “incomplete” cycles, the first of which lasts twice as long as the second one [partial two-cycle mixing (PTCM)]. This study involved the determination of the quality properties of bread (loaf volume, specific weight, crust thickness, crumb whiteness, crumb hardness index, and crumb heterogeneity index) under the effect of process modifications, analyzing the effect of dough mixing time and resting time between the mixing cycles. The study included also regression equations describing the physical properties of bread. Based on the tests performed, it was noted that in the case of flour characterized by poor baking quality, the process effectiveness can be enhanced through the application of two incomplete mixing cycles (PTCM), with dough resting time in the range of 10–20 min. This treatment resulted breads with significantly greater loaf volume, lower specific weight, lower whiteness index, and hardness compared to breads baked using the straight dough method. It is not recommended to use two equal duration cycles of dough mixing.     

EVALUATION OF A PROTEIN CONCENTRATE PRODUCED FROM GLANDLESS COTTONSEED FLOUR BY A WET-EXTRACTION PROCESS

Wet-extracted concentrate spray dried at two pH levels was evaluated for use in protein-fortified bread and as a component in meat loaf to reduce juice and fat cook-out during baking and to reduce meat requirement. Bread loaves containing air-classified glandless cone, 100% wheat flour and LCP glanded flour were significantly larger in volume than loaves from other blends, but there was no real difference among loaf volume of breads containing these three treatments. pH of spray drying had a marked effect on baking properties of the wet-process cone; pH 4.5 yielded a poor quality loaf while pH 6.8 loaf volume was equal to bread containing glandless cottonseed flours. Taste panel evaluations showed meat loaves containing 25% wet-extracted protein concentrate to be quite acceptable: milder or more bland than all-meat loaves and somewhat softer or smoother in texture.     

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 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.     

Breadmaking quality of ten greek breadheats. II. Relationships of protein,lipid and starch components to baking quality

Protein, lipid and starch components of ten Greek inter bread heats (four poor quality soft milling varieties, and to soft and four hard milling varieties of good quality) ere examined for possible relationships ith bread loaf volume and volumes in sedimentation tests for flour quality. High molecular eight glutenin subunit quality scores ere loer (4, 4, 6, 6) in the poor quality heats than in the good quality heats (6, 6, 6, 6, 8, 10) and ere only roughly correlated ith the other quality parameters. Gliadin electrophoregram patterns ere distinctive for most heats and might be useful for variety identification, but consistent occurrence of γ-gliadin 40, associated ith eakness, and γ-gliadin 43.5, associated ith strength, as not observed. The ratio non-polar/polar free lipids as highly correlated (P < 0.001) ith loaf volumes using both long fermentation and activated (chemical) dough development processes. Starch granule composition, selling and gelatinisation properties, hich ere very similar to those of other heat starches, did not relate to baking quality. A 15-kDa protein on the surface of starch granules associated ith endosperm softness as found in the soft heats.