Wheat Flour Enriched with Calcium and Inulin: A Study of Hydration and Rheological Properties of Dough

The aim of this work was to study the effect of calcium (Ca) carbonate-inulin (In) systems on hydration and rheological properties of wheat flour dough. Wheat flour, Ca carbonate from 108 to 252 (mg Ca/100?g flour) content, and enriched In oligofructose at levels of 1% to 13% (flour basis), were used. Hydration dough properties were researched analyzing water absorption (W _abs), moisture content (M _cont), water activity (a _w), and relaxation time (??). W _abs and a _w decreased with increasing In levels independently of Ca content. Dough development time increased with the amount of Ca. In the presence of In, samples with the lowest content of Ca were those showing the highest development time values. Inulin was the main component that controled W _abs in dough. In the presence of CaCO₃, although water seemed to be in a free state according to the high a _w value measured (>0.975), the low value of relaxation time obtained suggests less molecular mobility. Rheological properties of dough were studied by texture, relaxation, and viscoelasticity assays. Dough hardness and consistency significantly increased with Ca and mainly with In content. At high In content, dough texture was enhanced by CaCO₃ due to the fact that this salt could behave as dough strengthener. Adhesiveness of dough was not modified by CaCO₃ at low In levels. However, Ca affected adhesiveness at intermediate In levels. Adhesiveness was significantly increased by In presence. Calcium and In both diminished dough cohesiveness. The In presence increased dough elasticity, independently of Ca content. A second-order polynomial model and response surface methodology were used for studying hydration dependence and rheological parameters (R ²?>?0.771) on Ca and In. Dough M _cont varied with In² and mainly inversely proportional to In. An inverse dependence of ?? on In was detected. Dynamic and relaxation elastic moduli (G?? and E ₃) showed a linear dependence on In.     

Effects of Waxy Wheat Flour and Water on Frozen Dough and Bread Properties

ABSTRACT:  The quality of bread made from frozen dough is diminished by changes that occur during freezing. New cultivars of waxy wheat flour (WWF), containing less than 2% amylose, offer unique properties for the production of baked products. In this study, dough properties and bread quality were investigated at various levels of WWF (0% to 45% flour weight) and water (55% to 65%). Dough stickiness increased with higher levels of WWF and water. During frozen storage, dough with greater WWF and lower water had less change in stickiness. Maximum resistance to extension (MRE) decreased with higher WWF and water. Dough with greater WWF and less water had less change in extensibility after frozen storage. Dough with greater WWF and water was more extensible. Nuclear magnetic resonance (NMR) studies showed that frozen dough with higher WWF content had lower transverse relaxation ( T ₂) time of 9 to 11ms. After frozen storage, dough with higher WWF still showed lower T ₂. Dough with 15% WWF had higher yeast activity. Bread made from 15% and 30% WWF had higher volume in bread made from unfrozen and frozen dough. Bread firmness decreased with higher amounts of WWF and water. This research demonstrated that specific combinations of WWF and water produced a better quality of frozen dough and bread.     

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.     

Impact of wheat bran addition on the temperature‐induced state transitions in dough during bread‐baking process

Wheat bran‐mediated effects on temperature‐induced state transitions of proofed bread dough were studied as function of its level of replacement (5%–15%) to wheat flour. Proofed dough was subjected to rheological tests at small deformations. During heating of proofed dough from 30 °C to 95 °C, the value of elastic modulus (G′) attained its maximum at a temperature () that represented peak gelatinisation temperature (T_P). Dough with 15% bran depicted significant increase in T_P over other formulations. Bran addition increased glass transition temperature (T_g) of dough and suppressed drop in elastic modulus (G′) at T > T_g. The above events resulted in decreased loaf‐specific volume and increased crumb hardness. The former was caused by retarded bubble expansion during initial stages of baking, explained by reduced uniaxial and biaxial extensibilities of dough. Mean bubble size depicted an inverse relationship with the hardness of breadcrumb.     

Emulsifiers: Effects on Quality of Fibre-Enriched Wheat Bread

Resistant starch (RS) is a nutritional ingredient commonly used in bread products as dietary fibre (DF). This ingredient presents similar physiological functions than those imparted by DF, promoting beneficial effects such as the reduction of cholesterol and/or glucose levels on blood. Quality improvement of bread containing RS, with an optimized combination of emulsifiers, will be useful in the development of new and healthy bakery products. The objective of this research was to analyse the effects of different emulsifiers on several quality parameters of dough and bread prepared with wheat flour partially substituted with resistant starch as a dietary fibre. A blend of wheat flour/maize-resistant starch (MRS; 87.5:12.5) with sodium chloride, ascorbic acid, α-amylase, compressed yeast and water was utilized. Emulsifiers were incorporated to formulations in different levels according to a simplex centroid design. The viscoelastic, textural and extensional properties of dough were analysed. Bread quality was evaluated throughout the gelatinization and retrogradation of starch, specific volume of loaves, and texture and firmness of bread crumb. The incorporation of 12.5% (w/w) of MRS to wheat flour caused an increase of 5% in water absorption. Stability decreases markedly (from 9.9 to 2.2 min) and the mixing tolerance index increased (from 79 to 35 UF). The sodium stearoyl lactylate (SSL)–diacetyl tartaric acid esters of monoglycerides (DATEM) mixture increased hardness and resistance to extension on dough, whilst dough containing Polysorbate 80 (PS80) was softer; nevertheless, both types of dough retained less CO₂. An optimized concentration of the three emulsifiers (0.24% SSL, 0.18% PS80, 0.08% DATEM, w/w) was obtained by surface response methodology. The bread prepared with this combination of emulsifiers presented a considerable specific volume with a very soft crumb.     

质构仪在面团和面包品质评定中的应用研究(英文)

以八种品牌面粉为试验材料,采用英国 CNS-FARNELL 公司制造的质构仪测试了面团的硬度、弹性、粘力、粘着性、断裂力、断裂能量、断裂回复形变程度、回复能量、回复形变程度等九种指标,并通过相关分析研究了这些指标与面包品质(面包体积和弹性变化率)以及与小麦面粉的品质性状的相互关系。研究结果表明:面团的硬度、粘力与面包的体积呈正相关,相关系数分别为 0.546、0.568,弹性与面包的体积呈负相关,相关系数为-0.606;粘力与24h后室温下弹性变化率呈显著的正相关,相关系数为0.707。面团的质构特性与面粉的品质指标的相关性也非常明显。     

Wheat dough rheology and bread quality effected by Lactobacillus brevis preferment,dry sourdough and lactic acid addition

The influence of chemical and biological acidification on dough rheological properties and bread quality has been investigated. Two different flour types were used. Dough was chemically acidified with lactic acid. Two types of biologically acidified dough were prepared: dough with dry sourdough and with a Lactobacillus brevis preferment. Wheat dough rheological properties were investigated using the Farinograph, Extensograph and Amylograph. The baking response was also determined using standard baking tests. Addition of acidifiers resulted in firmer doughs with less stability, decreased extensibility and decreased gelatinisation maximum. The biological acidifiers increased the bread specific volume. Lactic acid addition had no influence on bread specific volume. In general, biological and chemical acidification decreased bread hardness. The addition of dry sourdough significantly decreased the lightness and increased the yellowness and redness of the bread crumb. The crust chroma, hue angle and brownness index were significantly changed by addition of acidifiers.     

Effect of Temperature on the Solubility of CO2 in Bread Dough

Dough expansion during fermentation is caused by CO₂ production by yeast, and its transfer from liquid state in the dough liquor to gaseous phase in the gas cells. The liquid-gas equilibrium is controlled by the solubility of CO₂ in the dough and by the Henry coefficient. The solubility of CO₂ in bread dough was measured for different temperatures with a specific device based on the evolution of the pressure during fermentation at constant volume. The measurements range from 15 to 40°C. Data obtained was extrapolated to 0 and 50°C. Values were found between 1.6 × 10^?5 and 5 × 10^?6 g CO₂ kPa^?1 g^?1 LPD, at 0 and 50°C, respectively (LPD: Liquid Phase of Dough).     

Fatty acid composition of traditional fermented and unfermented Turkish corn bread with the emphasis on<Emphasis Type="Italic"> trans</Emphasis> fatty acids

Dietary fat continues to be a major research priority because of its association with heart disease, cancer and other chronic diseases. On the other hand emerging data suggest that trans fatty acids may raise blood levels of low density lipoprotein cholesterol to much the same extent as saturated fatty acids. In this research cis and trans fatty acid composition of unfermented and fermented corn bread as well as flour used in the recipe, and dough samples were determined. Unfermented bread samples were made of corn flour, and fermented breads were made of corn flour-wheat flour mix (1/1) by the traditional straight dough method. Samples, including flour, dough and bread, were analysed by capillary gas-liquid chromatography for their fatty acid compositions. According to the results obtained, unfermented and fermented bread dough have the same fatty acid composition as the flour used in the recipe. Dough fermentation did not effect the fatty acid composition of corn bread. However, fatty acid composition changed slightly in the baked bread. The levels of palmitic, stearic and oleic acid increased, and those of linoleic, linolenic, arachidic and eicosenoic acids decreased, compared to flour and dough. Trans linolenic acid was also detected in both unfermented and fermented corn bread at a level of 0.1%. Slight changes in the fatty acid composition and formation of trans linolenic acid were a result of baking temperature.     

EXTENSIONAL FLOW STUDIES ON WHEAT FLOUR DOUGHS WITH DIFFERENT PROTEIN CONTENT1

Uniaxial compression technique was used to relate the rheological behavior of dough to wheat quality for bread. Dough of nine flours of the cultivar Rayon, grown in three different regions of Sonora, Mexico, and with a protein content from 10% to 12.8%, were studied using the lubricated squeezing‐flow test connected to a texturometer. Wheat flour quality determinations were protein, moisture and ash content, dry gluten, falling number, and sedimentation volume. Traditional dough rheological evaluations were made with the farinograph and alveograph. The baking test was also done. The extensional viscosity was measured at three crosshead speeds (0.2, 0.5, and 1.0 mm/min). Extensional viscosity, measured at the lowest speed, significantly (P < 0.05) and negatively correlated with protein content (r = ‐0.63) and bread volume (r = ‐0.72). The rheological behavior of wheat doughs during lubricated uniaxial compression showed dependence on the strain rate as demonstrated by the patterns of the extensional viscosity curves.     

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.     

The influence of 1B/1R chromosome translocation on gluten protein composition and technological properties of bread wheat

The Austrian bread wheat Amadeus without and with 1BL/1RS translocation and three further translocation genotypes with known HMW subunit compositions were grown under the same environmental conditions. Their flours were characterised by the determination of crude protein content and, partly, by the determination of glutathione and cysteine. Furthermore, the qualitative and quantitative composition of gluten protein types was analysed by a combined extraction and reversed phase HPLC procedure. Dough development time, maximum resistance and extensibility of dough and gluten, and bread volume were determined by means of microscale methods. Protein, glutathione and cysteine contents of flours were only slightly influenced by translocation. The HPLC patterns of gliadins and glutenin subunits showed that translocation caused characteristic changes concerning ω‐gliadins, γ‐gliadins and LMW subunits of glutenin. The amount of ω 1,2‐gliadins was significantly increased and that of LMW subunits decreased. The effect of translocation on the rheological properties of dough and gluten was characterised by a strongly reduced dough development time, reduced maximum resistance and increased extensibility. Bread volume was decreased by about 10%. The amount of glutenin subunits was correlated with dough development time, resistance of dough and gluten, and bread volume to a higher extent (r = 0.79–0.91) than the amount of gliadins (r = 0.52–0.80). Correlation coefficients for LMW subunits were higher (r = 0.82–0.88) than those for HMW subunits (r = 0.35–0.61) when all five wheats were included. Instead, when only translocation lines were considered, HMW subunits (r = 0.89–0.98) were more important than LMW subunits (r = 0.64–0.86). Altogether, the results demonstrate that translocation causes important quantitative as well as qualitative changes in gluten protein composition which can be efficiently determined by reversed phase HPLC. © 2000 Society of Chemical Industry     

A study on relationships between durum wheat semolina properties,technological mixing parameters and the properties of dough after mixing

Partial least square regression analysis was used to study the correlation between X variables (semolina quality, hydration level and mixing time) and Y variables, which were, in a first model, dough consistency during mixing, and, in a second model, dough properties after mixing (strength, elasticity, density) and leavening (maximum volume). The first model showed a predictive residual sum of squares (PRESS) of 2.98 and a predictive R² (Q²) of 0.92, and highlighted the key role of hydration and mixing time on dough consistency. The second model had the best PRESS (8.25) and Q² (0.94) values for dough volume and indicated that the volume increased with increasing mixing time until the dough consistency decreased of 20–30%. Dough volume was primarily affected by hydration. The model indicated that maximum volume after leavening, corresponding to optimum mixing time, was obtained with a soft and elastic dough, with a low‐density value.     

Identification and effect of ethyl galactoside on the properties and baking quality of dough

One of the reaction products of lactose and lactase in the presence of ethanol was isolated and identified as ethyl galactoside (EG) using gas-liquid chromatography, fast atom bombardment–mass spectrometry and ¹H and ¹³C Nuclear Magnetic Resonance Spectroscopies. Dough and bread qualities were studied by adding three different levels of EG (0.033, 0.067 and 0.134 mmol per kg of wheat flour) to the bread ingredients. Addition of 0.067 mmol EG per kg of wheat flour indicated significantly large loaf volume of the bread, and retarded the firmness of bread during storage when compared to the control. The small level of EG significantly improved the bread qualities as compared with lactose or a combination of lactose and lactase. And also, the wheat flour dough containing EG (0.067 mmol) significantly reduced the modulus of elasticity and viscosity coefficient. The addition of EG (0.067 mmol) to the bread ingredients slightly tended to lower the gelatinisation temperature of starch. The scanning electron microscopic observations indicated that the gluten portion of dough containing EG was developed well, and this caused the large loaf volume and good appearance from cross view of bread.     

Effect of Alkali Dipping on Dough and Final Product Quality

ABSTRACT: The effects of alkali dipping on starch, protein, and color changes in hard pretzel products have never been researched. Experiments were conducted to mimic reactions occurring on the pretzel dough surface. Dough was dipped in water or 1% sodium hydroxide solution at different temperatures between 50°C and 80°C. Protein and starch profile after dipping were analyzed. Color development on pretzel surface following the extraction of pigments from flour was investigated. Whole dough and pretzel samples were also made at pilot plant and the properties were analyzed. Only starch granules on the dough surface were gelatinized following dipping. Amylose-lipid complex dissociated at a lower temperature with alkali treatment but were not dissociated, even at high-temperature dipping in water. Treating the dough at 80°C in alkali solution resulted in the hydrolysis of proteins into smaller peptides that could be not precipitated by trichloroacetic acid (TCA). Dough surface color was different following pigment extraction from flour but not significantly different following baking. The results suggest that the color that developed on pretzel surface was not due to pigments present in the flour but was contributed by the reaction within or between the starch and protein hydrolysis derivatives during baking.     

Correlating dough elastic recovery during sheeting with flour analyses and rheological properties

The dough rheological behaviors of three flours having different chemical and physical properties were measured, as were changes in thickness and snapback (thickness of the machined dough sheet relative to the roll gap), immediately following sheeting. Dough snapback was determined to be a function of processing parameters, reduction ratio, and dough rest time, as well as different flour properties. The predication equation for dough snapback is based on multiple flour properties and sheeting conditions. Higher protein flours normally have stronger dough properties and larger snapback, compared with low protein flours, but also depend on the protein quality. The snapback will increase either with increased protein content, reduction ratio, or reduced rest time. Dough snapback using flour made by blending two flours 50/50 had intermediate values between the two original flours. Among the variables, Mixograph work, reduction ratio, and dough rest time were the main factors affecting the elastic characteristics of the doughs. Minimum snapback occurred with the weakest flour experiencing the longest rest time and the smallest reduction ratio. A linear 7‐factor equation was found to predict the snapback of several flours, by combining reduction ratio, dough rest time, Mixograph work, peak height, and mixing time, Alveograph P/L, and protein content. Only three factor combinations of Mixograph work, reduction ratio, and rest time were needed to develop a second order equation for predicting snapback. Copyright © 2008 Society of Chemical Industry     

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％．     

Dough properties and breadmaking qualities of whole waxy wheat flour and effects of additional enzymes

BACKGROUND: Waxy wheat, a new kind of genetically back‐crossed wheat, was applied to make whole bread in this study. Dough properties and bread quality of the whole waxy wheat flour, which was milled from 100% whole grains containing bran and germ, were determined. RESULTS: Whole waxy wheat had lower protein and lipid contents but higher dietary fiber content than whole regular wheat flour. Pasting temperature and viscosity of the whole waxy wheat flour were significantly lower than those of the whole regular wheat. However, the white wheat flour milled from wheat grains with 48% recovery had significantly higher peak viscosity than the whole waxy wheat. Bread made from the whole waxy wheat flour was significantly softer than that from the whole regular wheat flour during storage. However, bread made from whole waxy wheat had significantly lower specific volume than that from the white waxy flour because of the high amount of dietary fiber. Addition of cellulase increased paste viscosity, lowered dough mixing properties and reduced the firmness of the bread. The addition of pentosanase also increased paste viscosity, lowered dough mixing properties, improved loaf volume of bread but increased the firmness of breadcrumbs, while the addition of α‐amylase only increased final viscosity of flour and did not affect dough properties and bread qualities of whole waxy wheat flour. CONCLUSION: As a result, waxy wheat shows superior properties for making whole breads. Additional enzymes are also necessary to improve bread quality and nutritive values of whole waxy bread. Copyright © 2007 Society of Chemical Industry     

Production of iron-fortified bread employing some selected natural iron sources

Iron fortification of wheat breads is the optimal approach for reducing the high prevalence of iron deficiency in wheat-eating developing countries as in Egypt. The effectiveness of some natural iron-fortificants for potential use in Egyptian bread was tested. Defatted soybean flour, soybean flour, soybean hull flour, molasses and fenugreek flour at different levels besides FeSO₄ · 7H₂O as standard were separately incorporated in the wheat flour dough. Dough characteristics were studied using a Brabender Farinograph, where addition of such fortificants improves significantly (p < 0.05) the water absorption, development time, dough stability and dough weakening. Good breads with high nutritive value, excellent crust color, crumb grain and high overall acceptability were produced by adding either 10% defatted soybean flour, 5% soybean hull flour, 2% molasses or 4% fenugreek flour. Rat feeding trials have shown a good haematological response, i.e. higher haemoglobin (Hb) and haematocrit (Hct) values gained. Additional work is needed to identify other fortification options and to develop targeted fortification programes that will supply iron to all segments of a population in greatest need.     

Microbiological and technological characterization of sourdoughs destined for bread-making with barley flour

The aim of the present study was the microbiological and technological characterization of laboratory- made sourdoughs for use in barley-flour-based bread-making. A defined multi-strain starter culture consisting of selected lactic acid bacteria (LAB) and yeasts from wheat sourdoughs was inoculated into three flour–water mixtures, composed of: (i) 100% wheat flour (ii) 50% wheat flour and 50% hull-less barley flour (composite flour); (iii) 100% hull-less barley flour. After two months of continuous propagation, the chemical characteristics of the three sourdoughs were investigated by measuring: pH, total titratable acidity and concentrations of various microbial metabolites by HPLC (i.e. lactic, acetic, phenyllactic and butyric acids and diacetyl). The microbial traits were studied through viable counts, isolation and typing of LAB and yeasts and PCR-DGGE analyses. Only Saccharomyces cerevisiae and Lactobacillus plantarum were detectable in the sourdoughs together with other lactobacilli species which were different depending on the type of flour blend used. The molecular typing of the isolates highlighted that only a few strains among those initially inoculated prevailed. The volume increases of the three types of sourdough were also investigated and a correlation was seen between an increase in the barley flour content and a reduction in the dough volume.