Effect of α-amylases on dough properties during Turkish hearth bread production

Manufacture of gluten-free products requires the use of preselected raw materials. The number of such ingredients is limited; therefore, the portfolio of gluten-free bread is less variable and attractive in terms of their appearance, taste and nutritional value in comparison with traditional bread. The aim of the study was to apply debittered acorn flour as a natural nutritional enrichment of gluten-free bakery products and to check its effects on rheological properties of the dough and quality and staling of the bread. The analysis of rheological properties of gluten-free dough supplemented with acorn flour exhibited significant increase in the moduli G′ and G″ and a decrease in phase shift tangent, which denotes firming of dough structure. Introduction of limited amounts of acorn flour caused an increase in bread volume and improved crumb characteristics. In consequence of a diminished starch retrogradation, the respective loaves exhibited slower staling. Bread supplemented with acorn flour exhibited improved sensory acceptance. The obtained results signify that the application of debittered acorn flour in gluten-free baking could be useful for nutritional reasons, as it enriches bread with protein, minerals and dietary fiber, but also because of its technological effects, including structure strengthening, and sensory improvement.

ABSTRACTThe role of lipid‐binding proteins from wheat seed (puroindolines) on the breadmaking properties of wheat flour was investigated by determining the relationship between breadmaking quality and puroindoline content in samples of 32 wheat cultivars. An inverse relationship was mainly explained by the link between hardness and puroindoline contents. This link is in agreement with previous results which have shown a close structural identity between basic friabilins and puroindolines. Next, the effect of puroindolines in breadmaking was investigated by performing reconstitution experiments with two puroindoline‐free hard cultivars of opposite quality (Florence Aurore and Ecrin) as indicated in the screened wheat sample. Addition of 0.1% puroindolines to these flours drastically modified both the rheological properties of doughs and the structure of the bread crumb. Puroindolines are essential to the foaming properties of dough liquor, and a close relationship was found between the fine grain crumb provided by reconstituted flours with puroindolines and the fine structure of corresponding dough liquor foams. The effect of puroindolines on bread volume was mainly related to the rheological properties of wheat doughs.

Purpose. To investigate the patterns of changing the rheological properties of the dough and laboratory baking, depending on the amount of flour from different varieties of lupine added to wheat flour. Methods. The baking quality was analyzed using an alveograph and farinograph. Results. Based on the evaluation of alveograph, farinograph and laboratory bread baking, the patterns of changing the rheological properties of the dough when adding lupine flour to wheat flour were determined. The share of lupine variety’s influenced on flour strength, elasticity and stretchability of the dough, elasticity index ranged from 1 to 4%, with flour concentration – 82–98%. On the basis of the obtained data of the regression equation for the dependencies between the alveographer parameters and the amount of lupine flour added to wheat one were determined. A linear relationship was established between the physical characteristics of dough and the concentration of lupine flour. The proportion of the lupine variety impact on the time of dough formation, rate of dough fluidizing, valorimetric estimation of the flour mixture was 4–18%, the concentration of lupine flour was 57–76%. The bread loaf volume was for 86% determined by the concentration of lupine flour and for 6% by lupine variety. Based on the regression equations between the physical properties of the dough and the concentration of lupine flour, an exponential, linear, and polynomial dependence were found. The linear dependence was revealed between the bread loaf volume and the concentration of lupine flour in a lupine-wheat mixture. Conclusions. The rheological properties of the dough, as well as the bread loaf volume, were most influenced by the concentration of lupine flour in lupine-wheat flour mixture (57–98%). The share of influence on these indicators of lupine varieties used in the study did not exceed 18%. The revealed regression equations between the concentration of lupine flour and the physical characteristics of the dough allow predic­ting their changes depending on the amount of lupine flour added to wheat flour.

<p>Flaxseed (<em>Linum usitatissimum</em>) is an oilseed that is high in omega-3 fatty acid, dietary fiber and lignan. These components are responsible for the health promoting effects of flaxseed. Incorporating flaxseed into foodstuffs such as bread is an approach to increase dietary flaxseed. However, the need for a rapid screen method is needed since a complete baking process may take several hours. Correlating Farinograph parameters with bread characteristics may result in a rapid test that would allow for researchers to identify the proper levels of flaxseed addition to bread without a lengthy baking procedure. Therefore, the effect of 0, 6, 10, and 15% (wt/wt) flaxseed flour (FF) on Farinograph rheological properties of bread flour dough and on bread characteristics were investigated. Results showed that FF significantly (p< 0.05) increased dough water absorption, peak time, and mixing tolerance index, but decreased dough stability. Oven spring was significantly lower for all flaxseed treatments compared to the control. However, the loaf volume of bread made with 6 and 10% FF did not differ significantly (p < 0.05) from the control. The FF concentrations tested did not affect the specific volume of the bread even though the water absorption values were higher for doughs with FF. The breads containing flaxseed had darker crust color and a more yellow crumb color compared to control bread, but the crumb structure was not negatively impacted. Results indicated that Farinograph parameters of bread flour dough could be used as a method for screening FF addition to bread.</p>

The influence of the addition of four legume flours, chickpea, broad bean, common bean and red lentil (in amounts of 5%, 10% and 15% to a wheat-rye composite flour (50:50:0-control flour), in ratios of 50:45:5; 50:40:10; 50:35:15) was studied by analyzing the rheological properties of dough in order to further exploit the functionality of legume flours in bakery products. The rheological properties of dough were monitored using a Mixolab 2. A Rheofermentometer F4 was used to check the dough fermentation, and a Volscan was used for evaluating the baking trials. The addition of different legume flours in the mixtures resulted in different viscoelastic properties of the dough. The results showed a weakening of the protein network depending on the amount of legume flour added and on the specific legume flour. On the contrary, all samples with a higher proportion of legume flour showed an increased resistance to starch retrogradation. All flours had the ability to produce a sufficient volume of fermenting gases, with the exception of flours with a higher addition of broad bean flour, and the baking test confirmed a lower bread volume for bread with this addition. The results of the sensory evaluation indicated that legume flour additions resulted in breads with an acceptable sensory quality, in the case of additions of 5% at the same level as the bread controls, or even better. The aromas and flavors of the added non-cereal ingredients improved the sensory profile of wheat-rye bread. Breads with additions of chickpea, common bean and broad bean had a considerable proportion of darker colors in comparison to the control bread and bread with red lentil.

Plant-based dietary fibers play a fundamental role in improving human health. The objective of this study is to determine the effect of incorporating black plum powders (pulp and peel) on the thermal and rheological properties of wheat dough. The test dough cake samples were prepared with 0% (control), 3%, 5% and 7% replacement of wheat flour with black plum pulp and peel powders. Thermal and rheological properties of these doughs were determined using Differential Scanning Calorimetry (DSC) and rheometer, respectively. Thermal analysis showed a decrease and an increase in the peak temperature (Tp) (65.90 ± 0.01 - 65.22 ± 0.03℃) and gelatinization enthalpy (ΔH) (5.54 ± 0.33 – 6.71 ± 0.45 SI) of the wheat flour-black plum pulp or peel powder mixture, respectively. However, the gelatinization temperature range (TF –Ti) of the wheat flour starch did not significantly (P>0.05) vary. The doughs exhibited shear thinning (pseudo-plastic) behavior and a typical solid-elastic behavior. Both powders (pulp and peel) did not have significant effects (P>0.05) on the rheological properties (flow and viscoelasticity) of the dough. Black plum pulp (FVPu) and peel (FVPe) powders can be partially incorporated into wheat flour in the preparation of cakes without significant modifications to the properties of wheat dough.

The objective of this study was to evaluate the effect of single fermentation with Lactobacillus plantarum 1 (JC5) and Lactobacillus plantarum JCM1149 (C20), from one to 4 days, on the physicochemical and rheological properties of fermented quinoa doughs to make soft bread. A full factorial design using an ANOVA and Tukey test (p < .05) was used to evaluate the effects of two factors: bacterial strain (two levels) and fermentation time (four levels). The structure of the starch granules from fermented and unfermented quinoa, and wheat, using scanning electron microscopy were observed. Fermentation yielded doughs with higher soluble protein content and better textural properties than the unfermented quinoa dough after 2 days of fermentation by each strain, obtaining breads with a homogeneous porous crumb, good sensory quality, and high nutritional value. These results showed that it is possible to develop gluten-free breads with 100% of fermented quinoa. Practical application The results of this research will help both the bread making and cereal industries to design production processes taking into account fermentation technologies, aiming at improving rheological and nutritional properties of gluten-free breads. Furthermore, the culture media used in this study is a potential alternative to decrease costs linked to the amount of MRS (deMan-Rogosa-Sharpe) broth which are usually required to perform biotechnological processes. Finally, this research analyzes likely relationships among rheological properties of doughs and breads in order to anticipate textural quality of these baked goods.

Influence of water addition methods on water mobility characterization and rheological properties of wheat flour dough

Nowadays, demand for health-oriented products such as functional foods which hashigh fiber products is increasing. So, this work studied the effect of partial replacement of wheat flour(72% extraction) by different levels (5%,10%, 15% and 20%) of raw, soaked and germinatedfenugreek seed flour (Trigonella foenum graecum). The chemical and rheological characteristics forproduced dough blends, and on the sensory, physical and chemical characteristics for producedbiscuits were studied. Results indicated that incorporation of fenugreek seed flour (FSF) obviously (P≥0.05) increased in protein, fat, crude fiber, and ash with increasing FSF supplementing levels. Themineral contents of treated fenugreek seed flours almost was higher than the control samples.Germination process of fenugreek seed flour caused a decrease in the most of minerals compared withthe soaking process. The replacement of wheat flour with fenugreek seed flour caused a decrease (P≥0.05) in extensibility of the dough as measured by the extensograph and an increase (P≥ 0.05) inresistance to extension, proportional number and dough energy tests. Farinograph results showed thatall additions of fenugreek seed flour increased water absorption, dough development time and mixingtolerance index, while decreased dough stability and weakening values in the case of higher replacingwith fenugreek seed flour levels. The effects on dough development time, water absorption, andmixing tolerance indices were intensified with GF (germinated fenugreek seed flour) samples under5% or 10% levels. Generally, the addition of germinated fenugreek flour to wheat flour at ratio of 5 or10 levels had a less deleterious effect on the chemical and rheological properties of dough than that ofRF(raw fenugreek seed flour) and/or SF(soaked fenugreek seed flour). The sensory evaluation resultsof supplemented biscuit showed that a maximum of 10% FSF can be incorporated to made acceptablequality biscuits. While, biscuits containing 15 or 20% FSF were unacceptable to the panelists ascompared with the control biscuit. Results of chemical analyses indicated that incorporation of FSFinto biscuits formula obviously (p≥0.05) increased each of protein, fat, crude fiber, ash andindispensable amino acid (IAAs) contents with increasing FSF supplementing levels. The amino acidscomposition revealed that supplemented biscuits with FSF contained the most of IAAs and will covera highly percentages of reference protein pattern of FAO/WHO (1973). Lysine was the first limitingamino acid in control biscuit samples. Supplemented biscuits with germinated FSF had higher lysinecontents than other treatments. It could be concluded that, incorporation up to a 10% level ofgerminated FSF into wheat biscuit formula resulted in improving their chemical, sensory qualitycharacteristics and complementing the deficiency in lysine amino acid.

The aim of this study was to investigate the potential of the enzyme assisted bioprocessing with xylanase and sourdough fermentation on the rheological properties of dough, antioxidant properties and bread quality supplemented with oat bran. Mixing and starch pasting properties of the dough were studied with Mixolab device. The addition of 10, 20 and 30% oat bran to the wheat flour induced significantly increase (P < 0.05) of dough development time and dough weakening. Increasing the substitution level of wheat flour by oat bran resulted in decreased starch gelatinization temperature. Torque value related to starch gelling decreased from 2.470 to 2.224 N m, while cooking stability increased from 0.129 to 0.387 N m. Both enzymatic bioprocessing and sourdough addition allowed improving the bread specific volume and crumb hardness, especially because of the modification of the ratio between soluble and insoluble fibers. Moreover, enzymatic bioprocessing and sourdough fermentation increased the total phenolic contents of the bread. Practical Applications Using bioprocessing we can reduce the negative effect of bran addition on the dough rheology such as dough development time, dough stability and starch behavior during baking. Moreover, the bread quality in terms of specific volume and crumb hardness is also improving. The addition of different levels of oat bran in wheat flour can be used in order to improve the nutritional properties of bread, in order to enhance the health benefits of bread consumption.

Rheological Properties of Dough During Mechanical Dough Development

The combination of Rhizopus chinensis lipase (RCL) and transglutaminase (TG) was previously reported to improve the quality of frozen dough bread. In this study, the effects of RCL, TG, and their combination on the modification of glutenin macropolymer (GMP) and rheological properties of dough during frozen storage were investigated. Frozen storage changed both GMP and rheology properties of dough. TG treatment significantly decreased the ratio of high‐molecular‐weight glutenin subunits to low‐molecular‐weight glutenin subunits and GMP content in fresh dough, and GMP particle size increased. The effect of RCL on GMP properties was not significant, but its combination with TG dramatically increased the proportion of the larger particles and weighted average volume (D4.3) in GMP. The treatment with the enzyme combination could have inhibited the depolymerization of GMP, which slowed down the decrease rate of some parameters such as GMP content, proportion of larger particles, D4.3, and release of free amino and thiol groups during frozen storage. The modification of GMP properties by enzyme treatment weakened the effect of the freezing process on rheological properties of dough, especially TG treatment and its combination with RCL. Correlation between GMP particle size and dough properties (dough tensile force and elastic modulus) after freezing and enzyme treatment were confirmed.

The glutenins and gliadins were added to the base flour at varying concentrations of 2, 4, 6, 8, and 10 g/100 g flour, respectively. The addition of glutenins remarkably improved the mixing characteristics of the flour, while gliadins resulted in decreased dough stability and increased softening of the dough. The pasting characteristics varied with the varying concentrations of gliadins and glutenins. The peak viscosity decreased upon the addition of gliadins and glutenin, with gliadins being more effective in reducing the values of peak, final, breakdown, and setback viscosities. The hardness of the dough improved upon the addition of glutenins, while the gliadins resulted in dough with greater adhesiveness and cohesiveness. The gluten recovery increased by 98.79% upon addition of 10 g/100 g flour gliadins while the gluten quality measured in terms of gluten index was increased by the addition of glutenins.

Due to the different approach to the Russian and European flour milling process in Russia, the amount of damaged starch (SC) at flour mills is rarely controlled. This issue needs a comprehensive study, since the indicator of damaged starch is of great importance: its assessment allows determining the intended purpose of flour (bread baking, confectionery and pasta production). Manage the flour-grinding process in terms of monitoring the operation of the mill rolls during grinding, namely, checking their parallelism and wear, optimizing the gap and pressure. Flour with a high content of damaged starch should not be used for the same purpose as flour with a low content of damaged starch. Also, the assessment of the damaged starch index allows improving the dough yield by selecting the optimal water absorption coefficient (water absorption), optimizing the volume, color and shelf life of the finished flour products. At the initial stage, the purpose of the study was to identify the relationship between the amount of damaged starch and flour quality indicators, as well as the rheological properties of dough from laboratory flour and industrial grinding, and to further clarify the level of damaged starch on a large number of samples of flour of different quality according to its intended purpose. The available literature data on this issue are contradictory. The amount of damaged starch in flour was determined on a damaged starch analyzer. The following were also determined: the quantity and quality of gluten, the falling number, dough stability, liquefaction, water absorption of 20 samples of wheat flour of laboratory and industrial grinding. The results of the study showed that the amount of damaged starch in industrial milled flour was higher, and amounted to 20-27 UCD (average 24 UCD) versus 15-21 (average 18 UCD) in laboratory milled flour. A correlation was found only in industrial milling flour between damaged starch and the falling number (0.632), liquefaction (0.781) and water absorption (0.690). In industrial flour, with an increase in the amount of damaged starch, there was an increase in water absorption and liquefaction of the dough, which is consistent with the literature data; there was no clear decrease in dough stability. In the flour of laboratory grinding, the dependences between the indicators are insignificant.

Objective: In this study, wheat dough rheological property changes caused by water-soluble dietary fiber were investigated. Methods: Capillary Rheometer and Extensional Rheometer were used to detect dough samples with water-soluble dietary fiber in different concentrations. Results: Water-soluble dietary fiber affects dough rheological properties both in strength and resistance. Conclusion: When water-soluble dietary fiber concentration increased, dough became softer but stability and stir tolerance decreased.