Optimization of hydrocolloid addition to improve wheat bread dough functionality: a response surface methodology study

Effects of high ester pectin+α-amylase+sucrose (GNFZ), a high ester pectin+sucrose (BIG), xanthan gum (XANTHAN) and hydroxypropylmethylcellulose (HPMC) on wheat dough performance have been studied. Effects of hydrocolloids added singly and in association at different levels, on the investigated rheological, mechanical and thermal parameters have been evaluated by response-surface methodology. Optimum hydrocolloid formulations for white wheat bread are recommended.Positive linear and negative quadratic significant effects of GNFZ were observed on both the gluten index (GI) and the energy of dissociation of the amylose–lipid complex (ΔH_x). Optimized dosage of 1.36 g GNFZ/100 g flour, d.b. (maximum of the respective response surface plot) led to maximized values for both GI and ΔH_x, described as good indicators and predictors of the quality of fresh and stored formulated breads to be obtained. The strengthening effect of high ester pectin was reinforced by the negative quadratic effect of GNFZ on gluten extensibility, the positive effect of GNFZ/HPMC on the resistance to extension of gluten, and the negative synergistic effect of the pair BIG/HPMC on dough extensibility. XANTHAN when added singly induced desirable increase in dough resistance to extension, and the incorporation of the pair XANTHAN/GNFZ into dough formula is recommended because of the reduction of the induced degree of softening during mixing (farinograph) of GNFZ formulated doughs. A dosage of 0.109 g XANTHAN/100 g flour annulate the softening effect of GNFZ when added at an optimized dose of 1. 36 g GNFZ/100 g flour. Caution should be applied when added XANTHAN in presence of BIG because of the decrease in the extent of amylose–lipid complexation. Addition of HPMC at a level <1/>1 moderate/enhance, respectively, the effect of GNFZ on the resistance to extension of the gluten, and the water binding capability of BIG, and in this respect the incorporation of the cellulose derivative is encouraged at a dose dependent on the required effect.     

Antistaling Additives, Flour Type and Sourdough Process Effects on Functionality of Wheat Doughs

Antistaling additives—distilled monoglycerides (MGL), diacetyl tartaric ester of monodiglycerides (DATEM), sodium stearoyl lactylate (SSL), carboxymethylcellulose (CMC), hydroxypropylmethylcellulose (HPMC) and fungal α-amylase—were studied for effects on rheological and fer- mentative properties of white/whole wheat bread doughs, made following straight/sour dough processes. A fractionated factorial design (L³²) was used to evaluate single additive effects and interactions. Single addition of DATEM, followed by SSL, α-amylase and hydrocolloids improved oven rise and final volume. In presence of DATEM, synergistic (MGL) and antagonistic (SSL) effects of additional emulsifiers were found on gassing power. SSL was the only effective conditioner for enhancement of mixing properties. Dough plasticity was negatively affected by MGL addition and by CMC/HPMC in white/whole flours respectively. Some combinations resulted in detrimental dough handling properties.     

双乙酰酒石酸单双甘油酯对全麦面团特性及全麦馒头品质影响

为了改善全麦中麸皮带来的不利影响,本文尝试向全麦粉中添加双乙酰酒石酸单双甘油酯(DATEM,0~1.0%)改变全麦面团特性同时改善全麦食品品质。利用混合实验仪(Mixolab)、质构仪、动态流变仪、扫描电镜、激光共聚焦等研究了DATEM对全麦面团的混合特性、流变特性、拉伸特性和微观结构及其对全麦馒头比容、质构特性的影响。结果发现,DATEM使得全麦面团形成时间、稳定时间与回生值均升高,峰值粘度降低。DATEM添加增加了面团拉伸强度,弹性模量(G")和黏性模量(G"),但降低了面团延伸性。全麦面团微观结构显示,添加DATEM后面团内部断裂减少,结构均匀连续,面筋结构得到明显改善。DATEM使得全麦馒头硬度显著降低(p<0.05),由1546.70 g(对照)降低到680.56 g(DATEM 1.0%),当添加量为0.4%时,全麦馒头的比容比对照增加了1.2倍。     

Influence of additives on dough rheology and quality of <Emphasis Type="Italic">Thepla</Emphasis>: an Indian unleavened flatbread

Thepla is Indian unleavened flatbread made from whole-wheat flour with added spices and vegetables. In the present study, effect of addition of various emulsifiers such as sodium stearoyl-2-lactylate (SSL), di acetyl tartaric acid ester of monoglyceride (DATEM) and glycerol mono-stearate (GMS) were studied. Further hydrocolloids (guar gum, carrageenan) and modified polysaccharides [hydroxypropyl methylcellulose (HPMC) and carboxymethyl cellulose] were added at the concentration ranging from 0.25 to 1 % on the basis of whole wheat flour to prepared the doughs. These thepla doughs were analyzed for rheology and theplas were analyzed for tear force. Additives helped in improvement of dough and thepla quality. Guar gum increased dough stickiness and strength to the highest (31.12 and 1.76 g respectively). Also, guar gum decreased tear force value of thepla to 208.4 g. Tear force was found to be increasing with the duration of storage. Highest improvement in thepla dough and quality was obtained by the addition of guar gum at 0.75 % which retained the softest texture of thepla.     

Lipid binding in wheat-flour doughs: The effect of datem emulsifier

Binding of lipids and added fats increased as more work was applied to wheat-flour doughs mixed under nitrogen. Bound-lipid levels were lower in doughs mixed in air than in those mixed in nitrogen and increase in work input had little effect on the level of bound lipid in the former. The presence of DATEM emulsifier (diacetyl tartaric esters of mono- and diglycerides) had little effect on the air-mixed doughs, but brought about a considerable reduction in lipid binding in the doughs mixed under nitrogen. It is known that DATEM emulsifiers have profound effects on dough and bread properties and it is suggested that one effect of these emulsifiers is to maintain a pool of free lipid in the dough.     

Rheological properties of gluten-free bread formulations

In this study, the rheological properties of rice bread dough containing different gums with or without emulsifiers were determined. In addition, the quality of rice breads (volume, firmness and sensory analysis) was evaluated. Different gums (xanthan gum, guar gum, locust bean gum (LBG), hydroxyl propyl methyl cellulose (HPMC), pectin, xanthan–guar, and xanthan–LBG blend) and emulsifiers (Purawave^™ and DATEM) were used to find the best formulation for gluten-free breads. Rice dough and wheat dough containing no gum and emulsifier were used as control formulations. The rice dough containing different gums with or without emulsifiers at 25 °C showed shear-thinning behavior with a flow behavior index (n) ranging from 0.33–0.68 (except pectin containing samples) and consistency index (K) ranging from 2.75–61.7 Pa sⁿ. The highest elastic (G′) and loss (G″) module were obtained for rice dough samples containing xanthan gum, xanthan–guar and xanthan–LBG blend with DATEM. When Purawave^™ was used as an emulsifier, dough samples had relatively smaller consistency index and viscoelastic moduli values compared to DATEM. The viscoelastic parameters of rice dough were found to be related to bread firmness. Addition of DATEM improved bread quality in terms of specific volume and sensory values.     

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.     

Impact of microbial transglutaminase on the staling behaviour of enzyme-supplemented pan breads

The effects of microbial transglutaminase (TGM) when added singly and in combination with amylolytic (-amylase, NMYL) and non-amylolytic (xylanase) enzymes on the textural profile of fresh pan beads and pan breads stored for up to 20 days have been investigated in samples made with low and high extraction rate wheat flours following a sponge-dough process. White and whole-wheat enzyme-supplemented bread samples evidenced a similar sensory firming profile but a different quantitative instrumental staling pattern during storage. Two groups of samples with different staling behaviour can be defined according to the absence (faster staling kinetics) or the presence (slower kinetics) of NMYL in the bread formula, the separation being particularly clear for hardness, cohesiveness and resilience in white bread samples. TGM when added to NMYL-supplemented doughs induced synergistic beneficial effects on fresh bread quality and staling kinetics retardation. The binary combination led to breads with softer and less chewy fresh crumbs, increased initial crumb cohesiveness and resilience, and slower crumb staling kinetics and sensory deterioration during storage, particularly for samples made with white flour.     

Applicability of DATEM for Chinese steamed bread made from flours of different gluten qualities

BACKGROUD: The diacetyl tartaric acid ester of monoglycerides (DATEM) is an anionic oil‐in‐water emulsifier. The effects of DATEM on bread vary with the type of flour. However, there is insufficient information concerning the effects of DATEM on the qualities of Chinese steamed bread (CSB) even though it is also sold as a CSB improver. RESULTS: The effects of DATEM on CSB varied with flours. The overall qualities of CSB made from either weak or strong wheat flours were improved by the use of the additive, but the effects for medium strong flours were slight and uncertain. The effects of DATEM on individual parameters, such as specific volume, skin and inner structure, were similar to those on overall quality. The addition of DATEM increased the gluten strength and the dough stability of weak flour, whereas it weakened gluten strength and strengthened dough stability of strong flour. The addition of DATEM weakened the gluten strength and gave variable effects on dough stabilities for two medium strong flours. CONCLUSION: The effects of DATEM on CSB quality varied with flour type, by affecting flour characteristics, such as gluten strength, dough stability and lipid content. Copyright © 2008 Society of Chemical Industry     

Intracellular concentration of exogenous glycerol inSaccharomyces cerevisiaeprovides for improved leavening of frozen sweet doughs

Addition of glycerol to baker's yeast coupled with an incubation period under conditions of refrigeration to allow equilibration of the polyol across the yeast membrane, resulted in improved frozen sweet (10% sugar) dough leavening and keeping, relative to doughs made with yeast containing no added glycerol. Glycerol-loaded yeast showed smaller proof time increases after initial freezing and thawing. Also, glycerol treatment led to slower deterioration of the frozen sweet doughs during storage at −21°C for up to 8 weeks (proof time increases were significantly lower in stored frozen doughs made with glycerol-added yeast). Benefits of glycerol loading of yeast for the purpose of production of frozen plain (unsugared) doughs were less significant. The glycerol treatment effects became more significant as the yeast was stored refrigerated prior to mixing and freezing of doughs, i.e. shelf-life of yeast for use in frozen dough manufacture was improved by addition of glycerol. The improvements were dependent on glycerol concentration.     

Influence of acidification on dough viscoelasticity of gluten-free rice starch-based dough matrices enriched with exogenous protein

The impact of acid incorporation (acetic + lactic, 0.5%) into rice starch-based doughs enriched with different proteins (egg albumin, calcium caseinate, pea protein and soy protein isolates) at different doses (0, 5 and 10%) has been investigated on dough viscoelastic and pasting profiles. Oscillatory (stress and frequency sweeps) and creep-recovery tests were used to characterize the fundamental viscoelastic behaviour of the doughs, and thermomechanical assays were performed to assess dough viscometric performance. Supplementation of gluten-free doughs with proteins from vegetal sources led to more structured dough matrices (higher viscoelastic moduli and steady viscosities, and lower tan δ, instantaneous and retarded elastic compliances) effect being magnified with protein dose. Acid addition decreased these effects. Incorporation of proteins from animal source resulted in different viscoelastic behaviours according to the protein type, dosage and acidification, especially for casein. Acidification conferred lower dough deformation and notably higher steady viscosity and viscoelastic moduli for 5 %-casein-added dough. Protein-acid interaction favoured higher viscosity profiles, particularly for doughs with proteins of vegetable origin and lower dosage. Dough acidification decreased the pasting temperatures and the amylose retrogradation. Acidification of protein-enriched rice-starch doughs allowed manipulation of its viscometric and rheological properties which is of relevant importance in gluten-free bread development.     

Lipid binding of formula bread doughs Relationships with dough and bread technological performance

 Lipid binding of straight/soured started bread doughs treated with sodium carboxymethylcellulose (CMC), hydroxypropylmethylcellulose (HPMC), fungal α-amylase and monoglycerides (MGL), diacetyl tartaric acid esters of mono-diglycerides (DATEM) and sodium stearoyl lactylate (SSL) was investigated and results correlated with dough and bread performance during breadmaking and storage. For doughs formulated with MGL or DATEM, free and bound lipids accounted, respectively, for 70% and 30% of the increase in non-starchy lipids, which preferentially bind to gluten (MGL) and to the outside part of the starch granules (DATEM). SSL mainly increased the pool of free lipids and preferentially bound to the inside part of the starch granules and loosely to the gluten. Hydrocolloids preferentially bound to the gluten (CMC) and to the outside part of the starch granules (HPMC) respectively; this was associated with a significant displacement of endogenous gluten-bounded lipids to the starchy fraction (CMC) and with a significant decrease in lipids bound to the outside part of the starch granules (HPMC). The addition of α-amylase promoted a release of endogenous, bound lipids, and the sourer starter induced the aggregation of the starch-lipid complexes, revealed by the respective decrease in the level of gluten bounded lipids (α-amylase) and increase in the level of starchy lipids. Desired trends in dough lipid parameters resulting in strengthened gluten, delayed starch gelatinization, softer bread and reduced/delayed bread staling corresponded to high values of both free and starchy lipids, achieved by the incorporation of SSL and/or CMC into doughs. Received: 22 January 1998     

Physical characterization of fiber-enriched bread doughs by dual mixing and temperature constraint using the Mixolab®

Dietary fiber incorporation into bread dough systems greatly interferes with protein association and behavior during heating and cooling. The objective of this study was to understand the individual and combined effects of dietary fibers on dough behavior during mixing, overmixing, pasting and gelling using the Mixolab^® device. Impact of different commercial dietary fibers (inulin, sugar beet fiber, pea cell wall fiber and pea hull fiber) on wheat dough mixing, pasting and gelling profiles has been investigated. Mixolab^® plots indicate that the incorporation of sugar beet fiber into the dough matrix induces the disruption of the viscoelastic system yielding weaker doughs, and it greatly competes for water with starch affecting pasting and gelling. Conversely, inulin in the range tested seems to integrate into the dough increasing its stability. Additionally, the responses acquired with this device were compared with those obtained with other available methodologies, such as the Brabender Farinograph and the Rapid Visco Analyser, to explore its use as a suitable technique for studying fiber-enriched bread dough physical properties. A broad range of correlation between Mixolab^® and traditional devices were found.     

响应面法优化混合发酵制作冷冻面团馒头的复合食品添加剂配方

将酵母与酵子按4∶5的质量比混合,研究木聚糖酶、聚丙烯酸钠、双乙酰酒石酸单双甘油酯（diacetyltartaric acid ester of mono(di)glycerides,DATEM）、海藻糖4 种食品添加剂添加量对混合发酵剂制作冷冻面团馒头品质的影响。利用响应面分析法对4 种食品添加剂的配方进行优化。在单因素试验的基础上,进行Box-Behnken试验设计,得到了4 种添加剂对冷冻面团馒头感官总分影响的数学模型和最佳添加量。结果表明,4 种食品添加剂添加量对冷冻面团馒头品质影响顺序为：木聚糖酶＞聚丙烯酸钠＞DATEM＞海藻糖。冷冻面团馒头复合食品添加剂的最佳配方为：DATEM添加量0.15%、聚丙烯酸钠添加量0.05%、木聚糖酶添加量25.73 mg/kg、海藻糖添加量3.65%。在此条件下预期的酵子冷冻面团馒头的感官总分是84.646,实际得分为84±0.74。复合食品添加剂能够改善相同较高扫描频率条件下面团的流变学特性,增大其弹性模量（G’）和黏性模量（G”）。复合食品添加剂能够抑制冰晶的重结晶,减弱冰晶对混合发酵剂和面筋网络结构的破坏,从而提高了面团的加工品质和成品的质量。     

The Effect of Hybrid Carrageenan on the Thermo-rheological Properties of Gluten-Free Flour Doughs Using a Modified Kneading Protocol

Thermo-rheological behaviour of chestnut flour doughs supplemented with kappa/iota-hybrid carrageenan (HC) (up to 2.0%, flour basis (f.b.)) and sodium chloride (1.8%, f.b.) was determined at both target (C1) and final (C5) mixing peaks. For this purpose, small amplitude oscillatory shear (0.01 to 100 Hz), creep–recovery (loading of 50 Pa for 60 s, 30 °C), temperature sweeps (from 30 up to 180 °C) and heating/cooling cycles (between 30 and 60 °C) were conducted on a controlled stress rheometer. Previously, the thermal-mixing behaviour at proposed mixing temperature (50 °C) was conducted on Mixolab® apparatus. Results showed that the dough stability (from 2.2 to 5.8 min) in mixing stage and starch heat resistance to dough processing were significantly improved at proposed mixing temperature, even in the absence of HC. No statistical differences in rheological properties were observed for doughs evaluated in C1; however, those analysed in C5 were significantly modified in the presence of HC, mainly in terms of viscous behaviour (from 52.1 × 10⁶ to 39.1 × 10⁶ Pa s). Creep–recovery data sets, successfully fitted using Burgers model, revealed that the elasticity (J _r/J _max from 73.3 to 87.6%) of doughs analysed in C5 improved with HC addition. Thermal tests showed that the starch transitions were significantly promoted and stabilized with HC addition.     

Prediction of the rheological properties of wheat dough by starch-gluten model dough systems: effect of gluten fraction and starch variety

The present study sought to investigate the rheological properties of wheat starch-gluten (WS-G) and potato starch-gluten (PS-G) model doughs with different gluten fractions to elucidate the effectiveness of using model dough to predict wheat dough properties. The highest linear viscoelastic region, frequency dependence, maximum creep compliance and the lowest viscoelastic modulus and zero shear viscosity were observed in the wheat dough, followed by WS-G and PS-G model doughs. PS exerted a more significant damage effect on the gluten network while WS shared a tight integration with gluten protein, forming a more stable dough structure. The viscoelasticity of the model doughs shared a close association with the wheat dough under increased gluten fraction, while the frequency dependence of the model doughs showed no trend towards wheat dough. Therefore, starch-gluten model dough could not fully stimulate the functionality of wheat dough irrespective of its gluten fraction.     

Effects of dough mixing and oxidising improvers on free reduced and free oxidised glutathione and protein-glutathione mixed disulphides of wheat flour

Changes in free reduced glutathione (GSH), free oxidised glutathione (GSSG) and protein-glutathione mixed disulphides (PSSG) during dough mixing were monitored. After a rapid decrease in the GSH content and an increase in the GSSG content, the contents of both GSH and GSSG decreased progressively, whereas the PSSG content increased, as a simple flour-water dough was mixed. Total glutathione (GSH plus GSSG plus PSSG) levels in simple flour-water doughs and doughs treated with ascorbic acid or potassium bromate remained essentially constant during dough mixing, indicating that the reactions in which glutathione is involved are simple oxidations of sulphydryl (SH) groups to disulphide (SS) bonds and SH/SS interchange reactions. Yeast contributed high levels of GSH and GSSG to doughs, but analysis of dough aqueous phases (liquors) and the similarity of the PSSG contents of simple and yeasted flour-water doughs suggested that the yeast GSH and GSSG were largely unavailable to react with flour proteins. The GSH content of ascorbic-acid-treated and yeasted dough decreased rapidly on wetting the flour, the magnitude of the decrease indicating that the ascorbate oxidation system oxidised the yeast intracellular GSH as well as the flour GSH. With further mixing, the GSH content of the ascorbate dough remained constant at low levels similar to those of the simple flour-water dough. The GSSG content of the ascorbate dough increased rapidly on wetting the flour, but declined as dough mixing continued. The PSSG content of the doughs increased markedly as dough mixing proceeded to the optimum and then stabilised. The increase in the PSSG content lagged behind the rapid oxidation of GSH to GSSG. Potassium bromate caused a pattern of changes similar to those observed for ascorbate, but the changes in GSH and PSSG contents were smaller in magnitude. The results indicate that the changes in the different glutathione pools and the effects of oxidising bread improvers are rather more complex than envisaged previously, particularly the effects on PSSG.     

Ultrasonic Investigation of the Effect of Vegetable Shortening and Mixing Time on the Mechanical Properties of Bread Dough

ABSTRACT:  Mixing is a critical stage in breadmaking since it controls gluten development and nucleation of gas bubbles in the dough. Bubbles affect the rheology of the dough and largely govern the quality of the final product. This study used ultrasound (at a frequency where it is sensitive to the presence of bubbles) to nondestructively examine dough properties as a function of mixing time in doughs prepared from strong red spring wheat flour with various amounts of shortening (0%, 2%, 4%, 8% flour weight basis). The doughs were mixed for various times at atmospheric pressure or under vacuum (to minimize bubble nucleation). Ultrasonic velocity and attenuation (nominally at 50 kHz) were measured in the dough, and dough density was measured independently from specific gravity determinations. Ultrasonic velocity decreased substantially as mixing time increased (and more bubbles were entrained) for all doughs mixed in air; for example, in doughs made without shortening, velocity decreased from 165 to 105 ms⁻¹, although superimposed on this overall decrease was a peak in velocity at optimum mixing time. Changes in attenuation coefficient due to the addition of shortening were evident in both air-mixed and vacuum-mixed doughs, suggesting that ultrasound was sensitive to changes in the properties of the dough matrix during dough development and to plasticization of the gluten polymers by the shortening. Due to its ability to probe the effect of mixing times and ingredients on dough properties, ultrasound has the potential to be deployed as an online quality control tool in the baking industry.     

Pectins as Breadmaking Additives: Effect on Dough Rheology and Bread Quality

The effect of two types of pectins with different degrees of esterification on dough and bread characteristics was analysed. A high methoxyl pectin (HMP) and a low methoxyl pectin (LMP) were assayed in dough without or with salt (2%) at levels ranging from 0.25% to 2.0%. Farinographic water absorption increased when pectins were incorporated in dough with salt, whereas this effect was not observed in dough without salt. Pectin addition diminished the stability of dough in all cases. Texture profile analysis showed that pectins softened the dough, particularly when salt was added. Cohesiveness was also higher in doughs with salt at the maximum level of hydrocolloid addition. In dough with salt, HMP decreased the elastic and viscous moduli, while the values for tan (δ) were increased with respect to control. SEM micrographs showed that dough with pectin has a filamentous structure. In the breadmaking process, dough with HMP showed a better performance, leading to higher specific volumes and softer crumbs both in fresh and stored bread.