Dough Mixing Research Articles

Rheological Characteristics of Gluten after Modified by DATEM, Ascorbic Acid, Urea and DTT Using Creep-Recovery Test

The effects of diacetyl tartaric acid ester of monoglycerides (DATEM), ascorbic acid (AA), urea, and dithiothreitol (DTT) on viscoelastic properties of commercial hard red winter wheat gluten were investigated. A constant shear stress of 40 Pa was applied to gluten during creep-recovery test. Experimental creep-recovery compliance responses were fitted into a Burgers model with four elements accounting for characteristics of pure elastic (spring), viscoelastic (spring-dashpots elements), and viscous flow (dashpot). DATEM decreased the elasticity and viscoelasticity, but increased viscosity of gluten. The addition of AA, urea, and DTT, resulted in opposite rheological properties when compared with DATEM. Relationship among physical properties was also studied with principal component analysis (PCA) including gluten viscoelasticity, dough mixing and baking properties. Regressed coefficients from Burgers model accounted for higher percent of explained variance and were independent from flour content, baking and dough mixing properties.

Coexpression of the High Molecular Weight Glutenin Subunit 1Ax1 and Puroindoline Improves Dough Mixing Properties in Durum Wheat (Triticum turgidum L. ssp. durum)

Wheat end-use quality mainly derives from two interrelated characteristics: the compositions of gluten proteins and grain hardness. The composition of gluten proteins determines dough rheological properties and thus confers the unique viscoelastic property on dough. One group of gluten proteins, high molecular weight glutenin subunits (HMW-GS), plays an important role in dough functional properties. On the other hand, grain hardness, which influences the milling process of flour, is controlled by Puroindoline a (Pina) and Puroindoline b (Pinb) genes. However, little is known about the combined effects of HMW-GS and PINs on dough functional properties. In this study, we crossed a Pina-expressing transgenic line with a 1Ax1-expressing line of durum wheat and screened out lines coexpressing 1Ax1 and Pina or lines expressing either 1Ax1 or Pina. Dough mixing analysis of these lines demonstrated that expression of 1Ax1 improved both dough strength and over-mixing tolerance, while expression of PINA detrimentally affected the dough resistance to extension. In lines coexpressing 1Ax1 and Pina, faster hydration of flour during mixing was observed possibly due to the lower water absorption and damaged starch caused by PINA expression. In addition, expression of 1Ax1 appeared to compensate the detrimental effect of PINA on dough resistance to extension. Consequently, coexpression of 1Ax1 and PINA in durum wheat had combined effects on dough mixing behaviors with a better dough strength and resistance to extension than those from lines expressing either 1Ax1 or Pina. The results in our study suggest that simultaneous modulation of dough strength and grain hardness in durum wheat could significantly improve its breadmaking quality and may not even impair its pastamaking potential. Therefore, coexpression of 1Ax1 and PINA in durum wheat has useful implications for breeding durum wheat with dual functionality (for pasta and bread) and may improve the economic values of durum wheat.

Standardisasi Waktu Kerja Pada Unit Pengolahan Kakao, Koperasi Rimbun, Pidie Jaya

Standardization of Working Time at Cocoa Processing Unit, Rimbun Cooperative, Pidie JayaABSTRACT. Rimbun Cooperative is a business unit operating a chocolate factory producing several chocolate products such as cocoa fat, cocoa powder, 3 in 1 instant drinks (sachets), and chocolate bars. This research aims to measure standard times of operators in all working stations of the chocolate factory. These standards comprised the standards in roasting, peeling, pasting, pressing, powdering, powder sieving, powder mixing, dough mixing, refining, and chonching working stations. The data were directly collected using Time Study method with Stop Watch. The samples were randomly selected with five (5) repetitions; and the standard times were measured using Westinghouse Method to quantify performance and allowance factors. The result shows that standard times of operators in each working station are as follows: roasting (36 minutes), peeling (193 minutes), pasting (276 minutes), pressing (78 minutes), powdering (17 minutes), powder sieving (14 minutes), powder mixing (36 minutes), dough mixing (17 minutes), refining (30 minutes), and chonching (30 minutes). In peeling, pasting, powdering, powder sieving working stations, standard times of operators cannot be separated with working times of machines because the operators are required to run the machines (sequence). In general, standard times of operators, after calculation, are larger than direct records because during the working times, operators would not or could not use allowance factors for personal uses, such as for going to bathroom, drinking, and socializing with their colleagues as means to reduce stress or boredom.

Substituting Normal and Waxy-Type Whole Wheat Flour on Dough and Baking Properties

Normal (cv. Keumkang, KK) and waxy-type (cv. Shinmichal, SMC) whole wheat flour was substituted at 20 and 40% for white wheat flour (WF) during bread dough formulation. The flour blends were subjected to dough and baking property measurement in terms of particle size distribution, dough mixing, bread loaf volume and crumb firmness. The particle size of white wheat flour was the finest, with increasing coarseness as the level of whole wheat flour increased. Substitution of whole wheat flour decreased pasting viscosity, showing all RVA parameters were the lowest in SMC40 composite flour. Water absorption was slightly higher with 40% whole wheat flour regardless of whether the wheat was normal or waxy. An increased mixing time was observed when higher levels of KK flour were substituted, but the opposite reaction occurred when SMC flour was substituted at the same levels. Bread loaf volume was lower in breads containing a whole wheat flour substitution compared to bread containing only white wheat flour. No significant difference in bread loaf volume was observed between normal and waxy whole flour, but the bread crumb firmness was significantly lower in breads containing waxy flour. The results of these studies indicate that up to 40% whole wheat flour substitution could be considered a practical option with respect to functional qualities. Also, replacing waxy whole flour has a positive effect on bread formulation over normal whole wheat flour in terms of improving softness and glutinous texture.

Wheat Proteins—The Foundation of Breadmaking

In different breadmaking processes the methods for mixing and processing dough vary and, in principle, so should the qualities of the proteins present in the flour. It has long been known that flour (gluten) content and quality underpin bread quality, but we are still learning about the microscopic processes that ultimately control bread quality. The relationship between flour characteristics and bread volume has understandably been a key area of study, but perhaps we should be paying more attention to the interactions between dough and the processing methods used to turn dough into bread. Examples provided in the column demonstrate that flour protein has many different roles to play in delivering the bread quality that bakers and consumers seek. Because flour protein is vital to breadmaking, we must understand how to use it wisely.

Rheology of Gluten-Free Doughs from Blends of Chestnut and Rice Flours

Gluten-free flours blends using chestnut flour (CF) and rice flour (RF) were assayed in order to determine mixing and rheological properties of doughs at 30 °C as well as the thermal behaviour employing heating–cooling temperature steps. CF with different mean particle size (commercial, CCF: 169 μm and low particle size, CF1: 77 μm samples) was employed and blended with RF (46 μm) at several ratios (%) (CCF/RF: 90/10, 80/20, 70/30, 60/40, 50/50; CF1/RF: 25/75, 15/85, 5/95). Doughs from CCF, CF1 and RF flours were employed as reference systems. The rheological characterization of doughs conducted on the rheometer was performed by shear, oscillatory and creep-recovery assays. Rheological properties were significantly modified by flour ratio and by CF particle size. Creep-recovery curves showed that CCF/RF (70/30) and CF1/RF (25/75) improved the doughs elasticity by 41.1 % and 87.5 % compared with CCF and CF1, respectively. Cross, power and Burgers models were used to describe the flow curves, mechanical spectra and creep-recovery behaviour, respectively, of doughs. A mixing rule successfully reproduced the experimental data and fitting parameters of applied models as function of each flour fraction in the blends, except for oscillatory data.

Effect of Aspergillus niger xylanase on dough characteristics and bread quality attributes.

The present study was conducted to investigate the impact of various treatments of xylanase produced by Aspergillus niger applied in bread making processes like during tempering of wheat kernels and dough mixing on the dough quality characteristics i.e. dryness, stiffness, elasticity, extensibility, coherency and bread quality parameters i.e. volume, specific volume, density, moisture retention and sensory attributes. Different doses (200, 400, 600, 800 and 1,000IU) of purified enzyme were applied to 1kg of wheat grains during tempering and 1kg of flour (straight grade flour) during mixing of dough in parallel. The samples of wheat kernels were agitated at different intervals for uniformity in tempering. After milling and dough making of both types of flour (having enzyme treatment during tempering and flour mixing) showed improved dough characteristics but the improvement was more prominent in the samples receiving enzyme treatment during tempering. Moreover, xylanase decreased dryness and stiffness of the dough whereas, resulted in increased elasticity, extensibility and coherency and increase in volume & decrease in bread density. Xylanase treatments also resulted in higher moisture retention and improvement of sensory attributes of bread. From the results, it is concluded that dough characteristics and bread quality improved significantly in response to enzyme treatments during tempering as compared to application during mixing.

The Relationship Between Grain Hardness, Dough Mixing Parameters and Bread-Making Quality in Winter Wheat

The influence of grain hardness, determined by using molecular markers and physical methods (near-infrared (NIR) technique and particle size index—PSI) on dough characteristics, which in turn were determined with the use of a farinograph and reomixer, as well as bread-making properties were studied. The material covered 24 winter wheat genotypes differing in grain hardness. The field experiment was conducted at standard and increased levels of nitrogen fertilization. Results of molecular analyses were in agreement with those obtained by the use of physical methods for soft-grained lines. Some lines classified as hard (by physical methods) appeared to have the wild-type Pina and Pinb alleles, similar to soft lines. Differences in dough and bread-making properties between lines classified as hard and soft on the basis of molecular data appeared to be of less significance than the differences between lines classified as hard and soft on the basis of physical analyses of grain texture. Values of relative grain hardness at the increased nitrogen fertilization level were significantly higher. At both fertilization levels the NIR parameter determining grain hardness was significantly positively correlated with the wet gluten and sedimentation values, with most of the rheological parameters and bread yield. Values of this parameter correlated with quality characteristics in a higher degree than values of particle size index.

Optimization of Dough Mixing Time and Mixing Speed To Improve Dough Rheology and Quality of Barbari Bread Using Response Surface Methodology

Efforts to improve the quality of bakery products are increasing every day. Several techniques were developed for this purpose. In this study the possibility of betterment and optimization of quality properties of dough and Barbari bread with emphasis on process variables using rotatable response surface methodology were investigated. The independent process variables for baking process were dough mixing time at low speed (MTLS) (63 rpm) and high speed (MTHS) (180 rpm) from 2 to 8 min and dependent process variables were dough adhesiveness, dough cohesiveness, dough hardness, dough resilience, dough stickiness and specific volume of Barbari bread. Statistical results showed that all the process variables have a significant effect on all the responses. The linear terms of MTHS was the most effective factor on dough stickiness and dough resilience. Quadratic terms of MTHS and MTLS were the most effective factor on dough cohesiveness and dough hardness and specific volume of Barbari bread, respectively. Interaction terms of process variables have significant effect (p <0.05) on dough adhesiveness. Optimization showed that the best dough rheology and quality of Barbari bread were achieved when the MTHS and MTLS were 7.17 and 2 min, respectively. Keywords: Optimization, Response surface methodology, Quality, Processing variation, Barbari bread, Dough mixing

Potential of near Infrared Spectroscopy to Monitor Dough Mixing: From Crumbly Dough to Dilute Batter

Potential of near Infrared Spectroscopy to Monitor Dough Mixing: From Crumbly Dough to Dilute Batter

Modeling of Dough Mixing Profile Under Thermal and Nonthermal Constraint for Evaluation of Breadmaking Quality of Hard Spring Wheat Flour

ABSTRACTThis research was initiated to investigate associations between flour breadmaking traits and mixing and empirical dough rheological properties under thermal stress. Thirty hard spring wheat flour samples were analyzed by a Mixolab standard procedure. Mixolab profiles were divided into six different stages, and torque measurements of individual stages were modeled by nonlinear curve fitting using a compound of two solution searching procedures, multidimensional unconstrained nonlinear minimization and genetic algorithm. Mixing patterns followed exponential equations. Dough torque patterns under heat constraint, specifically dough thermal weakening and pasting profiles, were described by a sigmoid logistic equation as a function of time. Dough stability during heating appeared important for bread loaf volume increase from significant correlations between bread loaf volume and parameters generated from models of a dough thermal weakening stage. Multivariate continuum regression was employed to calibrate prediction models of baking traits using Mixolab parameters. Coefficients of determination estimated from prediction models and cross‐validation were greater than 0.98 for bake water absorption, mixing time, and bread loaf volume, indicating that the Mixolab parameters have a potential to enhance evaluation of flour breadmaking quality.

Analysis of Deoxynivalenol and Deoxynivalenol-3-glucoside in wheat

Deoxynivalenol (DON) is a mycotoxin which can be produced in cereal grains infected by Fusarium Head Blight (FHB). Alteration of DON by the plant often involves conjugation of the respective mycotoxin to certain functional groups or molecules. Conjugation of DON with glucose results in Deoxynivalenol-3-β-d-glucopyranoside (D3G), which has been found to be the main DON metabolite in wheat. The objective of this research was to identify the fate of D3G and DON during wheat processing using LC–MS–MS and GC, respectively. There was an approximate reduction of 61.8% in the detected DON level of the flour compared to the whole wheat. DON levels detected during the fermentation stage were significantly higher (P < 0.05) than the mixed dough. D3G detected in the flour was 23.7% lower than detected in the whole wheat. There were no significant differences (P < 0.05) in the D3G detected in the dough samples. However, the baked bread had significantly (P < 0.05) less D3G detected than the dough. Experiments were conducted to determine the effect of enzyme hydrolysis on DON detection in whole wheat. There were significant differences (P < 0.05) between the wheat treated with α-amylase, cellulase, protease, and xylanase. DON detection levels were significantly (P < 0.05) higher after treatment with protease (16%) and xylanase (39%) compared to the wheat composite. These results suggest that DON may be bound or embedded to the cell wall matrix or protein component of the wheat kernel due to the rise in detection of DON after these enzyme treatments.

S6 Supermarket bakers asthma: a report of three successive rounds of surveillance

In 2006, we set up a surveillance programme with a large UK supermarket employing almost 4000 “scratch” bakers (who mix dough and bake bread from scratch using raw ingredients) in around 350 stores. We report here the analysis of the programme through to 2010. The company occupational health provider screened all bakery workers for respiratory symptoms every other year, using a initial questionnaire (Level 1), with positive responders completing a subsequent, more detailed telephone-administered questionnaire (Level 2). Those who reported work-related nasal or respiratory symptoms were asked to provide a serum sample for specific IgE to bakery antigens. Those with positive specific IgE to flour or α-amylase (>0.35 kU/l) were directly referred for a specialist opinion. Abstract S6 table 1 shows the results of three surveillance rounds in 2006, 2008 and 2010. The frequency of work-related symptoms, sensitisation and disease across the three rounds of surveillance were remarkably constant. Measured prevalence is low (0.3–2 in 1000 bakers) although this figure is likely to be an underestimate; a previous study in the same workforce has demonstrated a reluctance to report symptoms and incomplete response rates.1 This system of surveillance is efficient but has thus far not been effective in reducing the incidence of occupational allergy.

Down-Regulating γ-Gliadins in Bread Wheat Leads to Non-Specific Increases in Other Gluten Proteins and Has No Major Effect on Dough Gluten Strength

BackgroundGliadins are a major component of gluten proteins but their role in the mixing of dough is not well understood because their contribution to wheat flour functional properties are not as clear as for the glutenin fraction.Methodology/Principal FindingsTransgenic lines of bread wheat with γ-gliadins suppressed by RNAi are reported. The effects on the gluten protein composition and on technological properties of flour were analyzed by RP-HPLC, by sodium dodecyl sulfate sedimentation (SDSS) test and by Mixograph analysis. The silencing of γ-gliadins by RNAi in wheat lines results in an increase in content of all other gluten proteins. Despite the gluten proteins compensation, in silico analysis of amino acid content showed no difference in the γ-gliadins silenced lines. The SDSS test and Mixograph parameters were slightly affected by the suppression of γ-gliadins.Conclusions/SignificanceTherefore, it is concluded that γ-gliadins do not have an essential functional contribution to the bread-making quality of wheat dough, and their role can be replaced by other gluten proteins.

Competition for Oxygen Among Oxidative Systems During Bread Dough Mixing: Consequences of Addition of Glucose Oxidase and Lipoxygenase on Yeasted Dough Rheology

ABSTRACTThe effect on O2 uptake during the mixing of yeasted dough, either unsupplemented or supplemented with glucose oxidase (GOX), horsebean flour (HB), soybean flour (SB), or combinations thereof, was studied using an airtight mixer. Two wheat flours with a low (flour A) and a high (flour B) content of free polyunsaturated fatty acids were used. Addition of HB or SB provokes a similar increase of O2 uptake for both wheat flours, whereas addition of GOX causes a larger increase for flour A than for flour B. When the wheat flours were supplemented with HB or SB, addition of GOX caused a small but significant increase of O2 uptake for flour A. This increase was not observed for flour B. The mixing tolerance of dough A, determined with the Chopin Consistograph, is increased by GOX addition. However, this effect is less pronounced when flour A is supplemented with HB or SB. Similarly, the relaxation index of dough B is decreased by GOX addition, but the decrease is less distinct in the presence of HB or SB. These results can be explained by a competition among yeast, GOX, and lipoxygenases (present in wheat, HB, and SB flours) for the O2 uptake by dough, which likely decreases the amount of hydrogen peroxide produced by GOX during dough mixing. This competition for O2 consequently also modifies the rheological properties of dough.

Registration of ‘Vision 30’ Wheat

‘Vision 30’ (Reg. No. CV‐1062, PI 661153) hard red winter (HRW) wheat (Triticum aestivum L.) was developed and tested as VA06HRW‐49 and released by the Virginia Agricultural Experiment Station in March 2010. Vision 30 was derived from the cross 92PAN1#33/VA97W‐414. Vision 30 is high yielding, awned, and semidwarf (Rht2) and has midseason spike emergence and resistance to powdery mildew [caused by Blumeria graminis (DC) E.O. Speer]. In Virginia, the average grain yield (2007–2009) of Vision 30 (5301 kg ha−1) was similar to that of the soft red winter wheat check cultivar Renwood 3260 (5536 kg ha−1). Vision 30 was evaluated in the 2008 and 2009 USDA‐ARS Uniform Bread Wheat Nursery and produced mean yields (4992 and 4690 kg ha−1) that were similar (P ≤ 0.05) to those of the highest‐yielding HRW wheat entry. In comparison with the hard wheat cultivar ‘Lakin’, Vision 30 has acceptable end‐use quality on the basis of flour yield (69.9 versus 70.3 g 100 g−1), flour protein (10.7 versus 9.5 g 100 g−1), flour water absorption (59.8 versus 59.1 g 100 g−1), dough mixing tolerance (3.3 versus 2.3), pup‐loaf volume (812 versus 803 cm3), and crumb grain scores (3.3 versus 3.7).

Registration of ‘Vision 40’ Wheat

The potential exists to develop and market hard winter wheat (Triticum aestivum L.) in the eastern United States, where a majority of the mills, bakeries, and consumers reside. The primary objective of this study was to develop adapted and competitive hard winter wheat cultivars possessing high‐value traits that offer the potential for new and expanded markets and greater profitability to wheat producers in the eastern United States. ‘Vision 40’ (Reg. No. CV‐1063, PI 661154) hard red winter (HRW) wheat was derived from the cross 92PIN#109/92PAN1#33 and released by the Virginia Agricultural Experiment Station in March 2010. Vision 40 was developed with a modified bulk‐breeding method and was tested as VA06HRW‐66 in replicated yield trials in Virginia (2007–2009) and in the eastern region (2008– 2009). Vision 40 is a high‐yielding, winter hardy, awned, semidwarf (Rht2) having mid‐ to late‐season spike emergence and moderate resistance to diseases prevalent in the mid‐Atlantic area with the exception of Fusarium head blight [caused by Fusarium graminearum (Schwabe)]. Vision 40 was the fourth highest yielding HRW wheat entry when averaged over 2 yr of the Uniform Bread Wheat Nursery grown at 11 test sites in 10 states in 2008 and 12 test sites in 9 states in 2009. In comparison with the hard wheat cultivar ‘Lakin’ (PI 617032), Vision 40 has acceptable end‐use quality on the basis of flour yield (70.2 versus 70.3 g 100 g−1), flour protein (9.5 versus 9.5 g 100 g−1), flour water absorption (58.5 versus 59.1 g 100 g−1), dough mixing tolerance (1.7 versus 2.3), pup‐loaf volume (823 versus 803 cm3), and crumb grain scores (3.6 versus 3.7).

Dynamics of γ-aminobutyric acid in wheat flour bread making

The dynamics of the health-improving non-protein amino acid γ-aminobutyric acid (GABA) during bread making were studied. Wheat flour contains trace levels of GABA (<15ppm) and ca. 160–175ppm of its precursor, glutamic acid (GA). During dough mixing, the levels of both GA and GABA largely increased. While wheat flour endogenous glutamic acid decarboxylase (GAD) performs some minor conversion of GA into GABA, yeast is the main contributor to GABA formation. Comparison of amino acid levels of dough samples, without or with yeast, indicated that yeast favours both GA and GABA formation already during mixing. Fermentation decreased both GA and GABA contents, due to amino acid consumption by the yeast, which used more GA than GABA. Proofing and baking resulted in large GABA losses, the latter probably in Maillard browning reactions during baking. Thermal loss of GA was less pronounced than that of GABA. Breads contained only trace levels of GABA and ca. 90–130ppm of its precursor. Exogenous supplementation of recombinantly produced GAD of Yersinia intermedia decreased GA levels in mixed and fermented dough and increased GABA levels. The highest GAD dosage used resulted in fermented doughs with ca. 300ppm of GABA, i.e. three times higher than the level present in the reference sample (no GAD added). After baking, a significant GABA level was left in the bread samples (ca. 115ppm) and GABA-enriched breads were obtained. Addition of sodium glutamate (100–380ppm) to a bread recipe containing no added GAD clearly indicated that its precursor was not the limiting factor for GABA conversion during bread making since the resulting breads contained no GABA, or only trace levels (ca. 20ppm).

Incorporation of high-molecular-weight glutenin subunits into doughs using 2 gram mixograph and extensigraphs

To study the contributions of high-molecular-weight glutenin subunits (HMW-GS) to the gluten macropolymer and dough properties, wheat HMW-GS (x- and y-types) are synthesized in a bacterial expression system. These subunits are then purified and used to supplement dough mixing and extensigraph experiments through dough partial reduction and reoxidation to allow these exogenously added HMW-GS to incorporate into gluten polymers. Detailed results are given for seven mixing and two extension parameters. HMW-GS synthesized in bacteria behaved similarly under these conditions to the same HMW-GS extracted from wheat flour. These experiments initially focused on the HMW-GS of the D-genome of hexaploid wheat encoded at the Glu-D1 locus; e.g. the Dx2, Dx5, Dy10, and Dy12 subunits. Experiments used five different flours and results are shown to be consistent when normalized to results from Dx5. The incorporation of Dx-type subunits into the gluten disulfide bonded network has greater effects on dough parameters than incorporation of Dy-type subunits. When Glu-D1 x- and y-type subunits are incorporated together, there are synergistic effects greater than those with either subunit type alone. This synergistic effect was greatest with approximately equal amounts of Dx- and Dy-type subunits – implying a 1:1 stoichiometric relationship.

Significance of lipid binding on the functional and nutritional profiles of single and multigrain matrices

Lipid fractions and starch- and protein-lipid binding of single and blended oat, rye, buckwheat and wheat flour, dough and bread matrices were investigated, and results correlated with the functional and nutritional properties of the grain matrices during mixing and baking. Non-starch lipid was the most prominent fraction in terms of absolute content and as a percentage of total lipids. Free lipids, starch lipids and bound lipids were, respectively, the major, intermediate and minor lipid fractions in flours, doughs and breads. Great differences in total lipid content due to sampling result in divergences amongst lipid fraction content and distribution, especially for starch and bound lipid fractions. Lipids bound to proteins during dough mixing are translocated and bound to starch during baking. In blended samples, the higher fibre content seems to provoke a reduction of the lipid–protein and lipid–starch linkages due to interactions between fibres and endogenous biopolymers. Starch lipid showed the most significant correlations with parameters related to dough and bread performance during breadmaking, especially over the mixing step. Valuable fresh bread functional characteristics, such as high specific volume and high sensory score for softness and overall acceptability, correspond to a starch lipid’s increase due to mixing. The higher the free and starch lipids decrease by reason of temperature treatment—baking—the larger the starch hydrolysis and the higher β-glucans and total dietary fibre contents.