Effect of wheat bran and enzyme addition on dough functional performance and phytic acid levels in bread

Effects of bran concentration, bran particle size distribution, and enzyme addition – fungal phytase, fungal alpha-amylase – on the mixing and fermentative behaviour of wheat dough and on the amount of phytic acid remaining in bread have been investigated using a factorial design of samples 2⁴. Bran concentration and bran particle size significantly affected all Farinograph parameters, whereas enzyme effects were particularly observed on both the water absorption of the flour and the parameters characterizing the overmixing. Water absorption was maximized in doughs with higher fine bran addition and/or in doughs with no enzymes, and was minimized in blends containing coarse added bran and alpha-amylase and/or alpha-amylase and phytase. alpha-Amylase addition had a significant positive effect on dough development and gassing power parameters during proofing. At low bran addition, phytate hydrolysis takes place to a greater extent than at high bran addition levels. Combination of bran with amylolytic and phytate-degrading enzymes could be advisable for overcoming the detrimental effect of bran on the mineral availability (phytase) or on the technological performance of doughs (alpha-amylase).     

Whole wheat bread: Effect of bran fractions on dough and end-product quality

Consumption of whole-wheat based products is encouraged due to their important nutritional elements that benefit human health. However, the use of whole-wheat flour is limited because of the poor processing and end-product quality. Bran was postulated as the major problem in whole wheat breadmaking. In this study, four major bran components including lipids, extractable phenolics (EP), hydrolysable phenolics (HP), and fiber were evaluated for their specific functionality in flour, dough and bread baking. The experiment was done by reconstitution approach using the 2⁴ factorial experimental layout. Fiber was identified as a main component to have highly significant (P < 0.05) and negative influence on most breadmaking characteristics. Although HP had positive effect on farinograph stability, it was identified as another main factor that negatively impacted the oven spring and bread loaf volume. Bran oil and EP seemed to be detrimental to most breadmaking characteristics. Overall, statistical analysis indicates that influence of the four bran components are highly complex. The bran components demonstrate multi-way interactions in regards to their influence on dough and bread-making characteristics. Particularly, Fiber appeared to have a high degree of interaction with other bran components and notably influenced the functionality of those components in whole wheat bread-making.     

Effect of wheat germ flour addition on wheat flour,dough and Chinese steamed bread properties

Wheat germ flour (WGF) has been developed as a functional food ingredient with high nutritional value. In this study, WGF was applied in steamed bread-making in order to improve the quality of Chinese steamed bread (CSB). Partial substitution of wheat flour with WGF at levels of 3%, 6%, 9% and 12% (w/w) was carried out to investigate physicochemical properties of blends and their steaming performance. Falling number (FN) values of composite flours ranged from 199 to 223 s. Viscosity analysis results showed that wheat flour mixed with WGF had higher pasting temperature and lower viscosities. Dough rheological properties were also investigated using farinograph and extensograph. The addition of WGF diluted the gluten protein in dough and formed weak and inextensible dough, which can be studied by scanning electron microscope (SEM) analysis. CSB made with WGF had significantly lower volume, specific volume and higher spread ratio. The sensory acceptability and physicochemical quality of CSB were improved with the application of a low level of WGF (3% and 6%). However, results showed that a high level of WGF over 9% is not recommended because of unsatisfactory taste. As a whole, addition of appropriate level of WGF in wheat flour could improve the quality of CSB.     

Effect of the addition of extruded wheat flours on dough rheology and bread quality

Extruded wheat flours, due to their increased water absorption capacity, constitute an opportunity to increase bread output in bakery production. However extrusion may modify dough and bread characteristics. The aim of this study was to investigate the effect of the substitution of 5% of the wheat flour by extruded wheat flour (produced with different time-temperature extrusion treatments) on dough mixing, handling and fermentation behaviour and bread volume, shape, texture and colour. The RVA curves indicate that extrusion intensity increases with increasing temperature or water content. Water absorption capacity rises with increasing treatment intensity, but dough stability tends to decrease. Adding extruded flours decreases dough extensibility but increases tenacity and gas production. Differences in dough structure were observed on photomicrography, though there were no clear differences in bread quality. These results indicate that it is possible to obtain adequate dough and bread characteristics using dough with 5% extruded wheat flour.     

Functional bread: Effect of inulin-type products addition on dough rheology and bread quality

The concerns for a healthy diet in terms of the consumption of baked products as fibre-enriched ones have been highlighted by increased consumers demand, food legislation and targeting manufacturers offer to healthy food. The objective of this study was to assess the effect of some inulin-type products added in bread-making aimed at producing functional bakery goods. In this purpose some physico-chemical characteristics and technological properties of the Romanian wheat flour half-white with addition of 5%, 10%, 15% and 20% inulin commercial products (% basis flour) were evaluated. Rheological behaviour was investigated using mixolab Chopin and baking tests for fibre-enriched products were performed. Changes of the rheological behaviour were noticed, in terms of a general decreasing trend of dough machinability due to enzymatic reactions probably influenced by changing the ratio of the main compounds and their interactions. Overall the bread loaves characteristics mainly affected by inulin addition were the volume and crust colour.Results indicated that inulin potential as fibre enrichment in wheat bread is limited, 15% Fibruline DS being a maximum percent to be used in bread-making of half-white flour, a dosage above being critically for dough rheological behaviour and the quality of high-fibre bread.     

Effect of the addition of bran fractions on bread properties

High fibre breads were produced adding durum wheat bran fractions of different composition and particle size. Fresh products were characterized for texture, crumb grain, volume, colour, water status (water activity, moisture content, frozen water content, ¹H molecular mobility).     

Effect of wheat dietary fibres on bread dough development and rheological properties

Several fractions of wheat fibres were isolated from starchy endosperm, aleurone layer and bran, and characterized for their hydration properties and arabinoxylans (AX) content. The influence of their addition, up to 10%, to standard flour was studied through mixing tests, and rheological tests at small and large deformations. The effect of insoluble AX on dough development was accounted for by their capacity to retain water, whatever their origin and percentage of addition. The addition of insoluble AX increased the viscoelastic plateau modulus. The addition of soluble and insoluble AX to the dough did not modify the overall dough flow behaviour in shear, characterized by a Newtonian plateau at low shear rates followed by shear-thinning behaviour at larger shear rates. This behaviour could be fitted by the Cross model. The addition of water soluble AX modified the Newtonian viscosity value. Conversely, the addition of insoluble ones increased dough consistency, probably through a filler-like effect in the dough matrix.     

Effect of barley flour addition on the physico-chemical properties of dough and structure of bread

The effects of different percentages of barley flour (i.e. 0–25%) in wheat flours on the physico-chemical properties and structure of dough and bread were investigated. As the percentage of barley flour in mixed flour was increased, its protein and gluten contents decreased whereas the ash content and enzyme activity increased. The rheological characteristics of the four dough mixes were studied using Farinograph, Extensograph and Alveograph. The water absorption (p < 0.01) and stability (p < 0.05) decreased significantly as the percentage of barley flour increased, while no changes were observed in the extensibility and maximum heights. Significant differences were observed in the structural and physical properties as well as in the image analysis of breads. With the increase in the percentage of barley flour, the crumb apparent density decreased (p < 0.1) whereas the porosity (i.e., fraction to total volume) increased (p < 0.1). Overall, the shape and pore structure at 10% barley flour (W90B10) were similar to the pure wheat flour bread, while addition at 15 and 25% of barley flour (W85B15 and W75B25) showed more non-uniform and larger pores.     

Effect of Oxygreen wheat ozonation process on bread dough quality and protein solubility

Oxygreen^® ozonation process for wheat grain is efficient to modify its technological properties. Experiments have been realized to evaluate the influence of operational conditions (humidification rate, ozone pressure and ozone concentration in the inlet flow). Dough alveographic data and protein solubility have been pursued.     

Effect of barley and oat flour types and sourdoughs on dough rheology and bread quality of composite wheat bread

The potential of sourdough to improve bread quality of barley and oat enriched wheat breads may depend on the characteristics of the added flour (cereal type, variety, extraction rate). We compared the effect of different barley flours and oat bran (substitution level 40%), unfermented and as sourdoughs (20% of total flour), on composite wheat dough and bread characteristics by combining empirical rheological analyses (DoughLab, SMS/Kieffer Dough and Gluten Extensibility Rig) with small-scale baking of hearth loaves. Whole grain barley flour sourdough increased resistance to extension (Rmax) of the dough and improved the form ratio of hearth loaves compared to unfermented whole grain barley flour. However, sourdough showed little effect on the breads prepared with sifted barley flour or oat bran. The breads made with oat bran showed highest bread volume, lowest crumb firmness and highest β-glucan calcofluor weight average molecular weight (MW). The heat treatment of oat bran inactivated endogenous enzymes resulting in less β-glucan degradation. High MW β-glucans will increase the viscosity of the doughs water phase, which in turn may stabilise gas cells and may therefore be the reason for the higher bread volume of the oat bran breads observed in our study.     

Impact of different beer yeasts on wheat dough and bread quality parameters

In order to investigate the impact of different yeast strains from the species Saccharomyces cerevisiae on the dough and bread quality parameters, wheat flour was fermented using different beer yeasts. The results show that beer yeast strains could be included in the baking process since S. cerevisiae T-58 and S. cerevisiae s-23 provided adequate gas production and dough formation with superior structural properties like extensibility and stickiness to S. cerevisiae baker's yeast. The resulting breads show the highest specific volume with the highest slice area and the highest number of cells and the lowest hardness over time. The different yeasts had also an impact on the crust colour due to their abilities to ferment different sugars and on shelf life due to the production of a range of different metabolic by-products. According to this study it was possible to produce higher quality bread by using yeast coming from the brewing industry, instead of bread containing standard baker's yeast.     

Study of the mechanism of improvement due to waxy wheat flour addition on the quality of frozen dough bread

Waxy wheat flour (WWF) was substituted for 10% regular wheat flour (RWF) in frozen doughs and the physicochemical properties of starch and protein isolated from the frozen doughs stored for different time intervals (0, 1, 2, 4 and 8 weeks) were determined to establish the underlying reasons leading to the effects observed in WWF addition on frozen dough quality. Using Nuclear Magnetic Resonance (NMR), Differential Scanning Calorimeter (DSC) and X-ray Diffraction (XRD) among others, the gluten content, water molecular state, glutenin macropolymer content, damaged starch content, starch swelling power, gelatinization properties, starch crystallinity and bread specific volume were measured. Compared to RWF dough at the same frozen storage condition, 10% WWF addition decreased dry gluten and glutenin macropolymer contents and T₂₃ proton density of frozen dough, but increased the wet gluten content, T₂₁ and T₂₂ proton density. 10% WWF addition also decreased damaged starch content, but increased starch swelling power, gelatinization temperature and enthalpy, crystallinity of starch and bread specific volume of frozen dough. Results in the present study showed that the improvement observed due to WWF addition in frozen dough bread quality might be attributed to its inhibition of redistribution of water molecules bound to proteins, increase in damaged starch content and decrease in starch swelling power.     

Biochemical and sensory evaluation of wheat bran supplemented sorghum bread

Addition of wheat bran to sorghum flour (Dabar cultivar) at two extraction rates 72% and 80% resulted in lowering reducing sugars. The percent decreasewas 75.6% compared with the control at the end of fermentation period. There was a highly significant (p 0.05) increase in crude fiber content as a result of addition of wheat bran. The increase was from 0.8 to 5.2 and from 0.5 to 5.3% for the 80% S/WB and 72% S/WB blends, respectively. Sorghum bread containing wheat bran was lower in reducing sugars and showed a significant increase (p 0.05) in starch content. Sorghum bread containing wheat bran resulted in a lower in vitro protein and starch digestibilities.     

豆粕和米糠中植酸含量的测定方法研究

采用分光光度法测定豆粕和米糠中的植酸含量.通过正交试验确定了最佳的提取、分离工艺为提取温度45℃、提取时间3 h、D201大孔阴离子交换树脂、流速0.5 mL/min,测得米糠中植酸含量为70.39 mg/g,豆粕中植酸含量为21.42 mg/g.该方法操作简单、准确度较高,适用于农副产品中植酸含量的定量测定.     

Properties of bread made from frozen dough containing waxy wheat flour

The quality of bread made from frozen dough is diminished, and staling rate is increased by changes that occur during freezing and storage. New cultivars of waxy wheat flour (WWF), containing higher levels of amylopectin, may help improve the quality of baked products. Bread quality and staling were investigated for bread containing 0–45% WWF and 55–65% water after freezing and 90-day frozen storage. The specific volume was highest with 15% WWF substitution and 60% water in bread made from both unfrozen and frozen dough. With higher levels of WWF and lower water content, bread staling rates decreased. Bread with higher levels of WWF were darker and had greater color variation. ¹H NMR studies showed that bread with greater WWF and water had higher transverse relaxation (T₂) times (9–11 ms), but less change in T₂ during storage. This research demonstrated that specific combinations of WWF and water produced a better quality of bread after dough freezing.     

Properties of bread made from frozen dough containing waxy wheat flour

The quality of bread made from frozen dough is diminished, and staling rate is increased by changes that occur during freezing and storage. New cultivars of waxy wheat flour (WWF), containing higher levels of amylopectin, may help improve the quality of baked products. Bread quality and staling were investigated for bread containing 0–45% WWF and 55–65% water after freezing and 90-day frozen storage. The specific volume was highest with 15% WWF substitution and 60% water in bread made from both unfrozen and frozen dough. With higher levels of WWF and lower water content, bread staling rates decreased. Bread with higher levels of WWF were darker and had greater color variation. ¹H NMR studies showed that bread with greater WWF and water had higher transverse relaxation (T₂) times (9–11 ms), but less change in T₂ during storage. This research demonstrated that specific combinations of WWF and water produced a better quality of bread after dough freezing.     

Effect of inulin with different degree of polymerization on plain wheat dough rheology and the quality of steamed bread

The aim of this study was to evaluate the effect of different polymerization degree of inulin on plain wheat dough rheology and quality of steamed bread. It was found the water absorption of dough decreased with the increasing of short-chain (FS) and natural inulin (FI) and increased with the increasing of long-chain inulin (FXL) higher than 7.5%. Three kinds of inulin all increased the development time, stability and farinograph quality number and decreased softening degree of the dough. When proof time was less than 90min, the extensibility increased with the substitution of 5% of FS, 5% of FI and 2.5% of FXL. The resistance to extension, ratio number of resistance to extensibility and energy all increased with the increasing of FS and FI as well as the time. While the energy increased with FXL substation at 45min and dropped thereafter, regardless of the concentration. The addition of inulin all enhanced the brightness, specific volume and hardness of steamed bread and decreased the water content, vaporization enthalpy, springiness, recovery, and cohesiveness. During the storage, inulin reduced the change rates of relative hardness, recovery, and cohesiveness and increased the change rate of relative enthalpy, which restrained the staling rate of steamed bread.     

Effect of physicochemical and empirical rheological wheat flour properties on quality parameters of bread made from pre-fermented frozen dough

The objective of this study was to examine the influence of flour quality on the properties of bread made from pre-fermented frozen dough. The physicochemical parameters of 8 different wheat flours were determined, especially the protein quality was analysed in detail by a RP-HPLC procedure. A standardized baking experiment was performed with frozen storage periods from 1 to 168 days. Baked bread was characterised for specific loaf volume, crumb firmness and crumb elasticity. The results were compared to none frozen control breads. Duration of frozen storage significantly affected specific loaf volume and crumb firmness. The reduction of specific loaf volume was different among the used flours and its behaviour and intensity was highly influenced by flour properties. For control breads wet gluten, flourgraph E7 maximum resistance and RVA peak viscosity were positively correlated with specific loaf volume. However, after 1–28 days of frozen storage, wet gluten content was not significantly influencing specific loaf volume, while other parameters were still significantly correlated with the final bread properties. After 168 days of frozen storage all breads showed low volume and high crumb firmness, thus no significant correlations between flour properties and bread quality were found. Findings suggest that flours with strong gluten networks, which show high resistance to extension, are most suitable for frozen dough production. Furthermore, starch pasting characteristics were also affecting bread quality in pre-fermented frozen dough.     

Effect of particle size and addition level of wheat bran on quality of dry white Chinese noodles

Wheat bran is one of the major dietary fiber sources widely used in the food industry in order to produce fiber-rich foods. The effects of particle size and addition level of wheat bran on the quality of flour and of dry white Chinese noodles (DWCN) were investigated. Results suggested that increasing wheat bran concentration and particle size decreased midline peak value (MPV). However, the MTxW and MPT increased as particle size increased. Peak viscosity, trough, final viscosity, area of viscosity, breakdown, and setback of blends decreased significantly with increasing bran levels from 5% to 20%, but there were no significant differences in the impact of particle size on pasting properties. For the 5% and 10% addition levels, there was no distinct effect in breaking strength of the noodles when bran size was 0.21 mm and 0.53 mm. Hardness, gumminess and chewiness of cooked DWCN showed a downtrend with increasing addition levels and particle size, while adhesiveness showed uptrend. The total score of DWCN showed a downtrend with increasing of addition level and particle size. For the 5% bran level, the scores of cooked DWCN were more than 83 when wheat bran particle size was 0.21 mm and 0.53 mm. By using 5–10% fine bran or using 5% medium bran in wheat flour, it is possible to satisfactorily produce fiber-rich DWCN.