History, mechanism of action, and toxicity: a review of commonly used dough rheology improvers.

Dough rheology improvers, which often are oxidative reagents in nature, have long been used in bread-making industry to enhance protein crosslinking and subsequently improve the dough rheological properties and bread qualities. Numerous studies were conducted to explore the effects of these oxidative agents on dough quality improving, however, the underlying mechanism of their action during dough development has not been fully understood. Due to the public health concerns, multiple oxidative reagents were banned in some countries across the world, while others are still permitted in accordance with regulations. Therefore, a comprehensive understanding of their application, significance, and safety in bread manufacturing is necessary. This review aims to provide a detailed information about the evolutionary history of several commonly used oxidants acting as dough rheology improvers, their mechanisms of action, as well as their potential toxicity.

Impact of pomegranate fruit powder on dough, textural and functional properties of fresh noodle.

BACKGROUND: Polyphenols are important functional food ingredients due to good performance in the prevention of chronic diseases and elongation of shelf-life. Numerous studies have shown that the addition of polyphenols of natural origin to wheat flour tends to have a contradictory effect on the physicochemical properties of the dough in the presence of different doses of polyphenols, also known as biphasic regulation. In the meantime, a promising and economic flour enhancer of natural origin is needed because of the short stability time of the dough. In this study, the impact of pomegranate fruit powder (PFP) on mixing and rheological properties of the dough and texture as well as nutritional characteristics of cooking noodles was studied. RESULTS: The mixing and tensile properties as well as viscoelasticity of the dough were improved with the addition of 4%, 8% or 12% PFP; correspondingly, a more compact and ordered microstructure was observed in the dough. The addition of PFP maintained the best cooking time and water absorption of noodles. Moreover, the hardness, tensile strength and resilience of noodles were improved with the addition of 4% or 8% PFP. Furthermore, the antioxidant capacities of noodles with the addition of PFP were increased via quantification of iron ion reduction, DPPH and ABTS scavenging capacity. The noodles added with PFP showed a dose-dependent inhibitory effect on glucose release. CONCLUSION: PFP improved the textural properties and nutrition value of noodles. The addition of PFP to the wheat four dough and noodles was suggested to be below 12%. © 2023 Society of Chemical Industry.

Effect of yeast on functional and rheological characteristics of whole wheat flour and its effect on quality of chapati.

Chapati is unleavened flat bread originated from Indian sub-continent and is considered as staple product in everyday meals. Its quality attributes are dependent on number of factors including the wheat used, ingredients added and processing parameters. The study was aimed to observe the effect of yeast addition on functional, rheological, and sensory characteristics on whole wheat flour and chapati at varying percentage (0.25-1.0). All the experiments conducted were compared with a control flour/chapati without yeast addition. The results showed that all the attributes were favourably affected with yeast addition when compared with control samples. It was noticed that the peak viscosity, setback, breakdown and final viscosity decreased with yeast addition and the paste obtained had higher gel strength. Alveogragh results also depict the increase in tensile strength and decrease in extensibility of dough on yeast incorporation. Textural and sensory studies revealed that yeast concentration upto 0.75% w/w in whole wheat flour resulted in chapati with good overall acceptability.

Carnauba wax utilization in salt encapsulation: application in bread.

The present work aims to develop encapsulated NaCl in carnauba wax for bread application, to reduce the salt utilization and assess its impacts on the rheological dough parameters and saltiness perception. Encapsulated salt was obtained blending salt crystals and molten Carnauba wax. Four different bread formulations were produced: 2.0% non-encapsulated salt; 2.0% Encapsulated Salt; 1.5% Encapsulated Salt; 1.0% Encapsulated Salt. Farinograph and alveograph analyses were performed to assess the dough rheology parameters and sensory analysis was conducted to evaluate saltiness. Encapsulation was effective to control Na+ ions release. They vary from 17 to 32 ppm the dissolution of sodium ions in the non-encapsulated and encapsulated samples, respectively. The alveograph and farinograph analyses showed that the 1.5E bread formulation was the closest to the control sample in rheological properties. Finally, a sensory analysis showed no difference in the saltiness perception between control and 1.5% encapsulated salt (4.65 and 4.69 respectively), indicating that carnauba wax encapsulated salt effectively reduced until 35% of salt the bread without changing the saltiness.

Effect of Fenugreek fiber on Rheological and chapati making quality of whole wheat flour.

Increase in awareness of consumers and demand has led to the development of various fibre rich food products from different fiber source. In the present work novel roller milled fenugreek fiber rich fraction (FFRF) rich in galactomannans was used for the development of high fiber chapati. Farinograph water absorption and dough stability increased with increase in the addition of FFRF in blends. The creep measurement results showed reduction in the maximum creep compliance and viscoelastic compliance while the zero shear viscosity showed the increasing trend with the increase in the addition of FFRF. The pliability of chapatis significantly decreased on addition of FFRF. The sensory evaluation concluded that the chapati with 10% FFRF is acceptable. The shear force value of chapatis prepared from the control and WWF-FFRF blends were decreased as the storage time increased showing brittleness in the chapatis. The micrographs of an outer layer of chapati (crust) showed partially gelatinized starch. The crumb micrographs of the WWF-FFRF blends chapatis showed large and small starch granules coated with galactomannans gums, and this coating increased with increased addition of FFRF. The composition of 10% fenugreek fiber chapati contained higher amount of minerals, insoluble and soluble dietary fiber compared to that of control sample. The in vitro starch digestibility of formulated chapati showed significant decrease in the values.

PDI-Regulated Disulfide Bond Formation in Protein Folding and Biomolecular Assembly.

Disulfide bonds play a pivotal role in maintaining the natural structures of proteins to ensure their performance of normal biological functions. Moreover, biological molecular assembly, such as the gluten network, is also largely dependent on the intermolecular crosslinking via disulfide bonds. In eukaryotes, the formation and rearrangement of most intra- and intermolecular disulfide bonds in the endoplasmic reticulum (ER) are mediated by protein disulfide isomerases (PDIs), which consist of multiple thioredoxin-like domains. These domains assist correct folding of proteins, as well as effectively prevent the aggregation of misfolded ones. Protein misfolding often leads to the formation of pathological protein aggregations that cause many diseases. On the other hand, glutenin aggregation and subsequent crosslinking are required for the formation of a rheologically dominating gluten network. Herein, the mechanism of PDI-regulated disulfide bond formation is important for understanding not only protein folding and associated diseases, but also the formation of functional biomolecular assembly. This review systematically illustrated the process of human protein disulfide isomerase (hPDI) mediated disulfide bond formation and complemented this with the current mechanism of wheat protein disulfide isomerase (wPDI) catalyzed formation of gluten networks.

From seed to bread: variation in quality in a set of old durum wheat cultivars.

BACKGROUND: Old durum wheat varieties are being appreciated again because of their interesting genetic diversity and low fertilizer needs. RESULTS: The agronomic and bread-making performances of 14 old Italian durum wheat varieties grown under two low nitrogen (N) inputs (46 and 86 kg ha-1 ) were determined and the relationships among grain, semolina, dough and bread quality parameters were established. The old varieties yielded similarly to the check modern variety Svevo under both N levels. Increasing N fertilization from 46 to 86 kg ha-1 did not increase grain yield or the mg of N in the grain, although grain protein percentage increased as a result of a decrease in grain weight and an increase in gliadin content. Despite the resulting decrease in the gluten index, dough and bread quality improved at the higher N rate, highlighting the influential role of protein percentage and gliadin in bread quality. The genotypic variation in grain protein percentage among old varieties was more strongly associated with glutenin than with gliadin content. Variation in the gluten index was high (4-54); indeed, it was the most variable semolina parameter, and proved to contribute the most to variation in bread quality. This variation was independent of the glutenin alleles (HMW 20, 20*, 7, 13+16, 6+8) and was linked to the quality of the grain in terms of grain weight and the associated mg of N per grain. Remarkably, two old varieties, namely Calabria and Cappelli, were able to produce both a good yield and high-quality bread. CONCLUSION: Old Italian durum wheats continue to boast significant biodiversity and are worth exploring in low-input production systems. © 2019 Society of Chemical Industry.

Influence of heat treatment for some wheat milling fractions on fino bread quality.

The influence of incorporating dry-heated wheat bran, at 5, 10, 15, and 20 g/100 g levels with dry-heated wheat germ at 3 g/100 g level, on fino dough rheology and bread quality was studied in comparison with fino bread containing unheated fractions, and white wheat bread. Dry heat treatment showed insignificant effects on the chemical composition and the dietary fibers of wheat bran and wheat germ, but was effective in reducing lipase activity by half in wheat bran, and by 100% in wheat germ. Dough containing dry heated fractions lowered the water absorption, extended the development time, strengthened the protein network, and increased the stability time, starch gelatinization, hot-gel stability, and starch retrogradation. Fino bread had larger loaf volume, darker crumb color, and lesser firm, gummy, and chewy texture. Sensory acceptability of fino bread loaves containing heated fractions indicated significant (P ≤ 0.05) improvement in taste, flavor and overall acceptability scores. Fino bread provided 9.0 to 21.5% of the dietary fiber intake (DFI) for the adults, showed significant loss of phytic acid (30-34%), had higher significant total phenolic contents (109.2-198.2 mg GAE/100 g), and antioxidant activity (40.17-47.46%). Levels of 10 and 15 g heated bran with 3 g heated germ/100 g showed acceptable results among all studied characteristics. Dry heat treatment could be applied on wheat bran and wheat germ to mitigate their negative influences on dough rheological behavior, and to deliver functional fino bread to consumers, with more dietary fiber, high-quality nutrients and antioxidant activity.

Effects of beta-glucan and resistant starch on wheat dough and prebiotic bread properties.

White wheat flour is a poor source of dietary fiber. Therefore a demand exists for enrichment of bread with non-digestible prebiotic ingredients that exert health-promoting effects. In this study, the effects of beta-glucan (BG) and resistant starch (RS) on the dough properties and bread-making characteristics were investigated. The water absorption of doughs increased with increasing BG and RS levels. Also, development time and farinograph quality number of BG-enriched doughs remained similar to that of the control while the doughs stability decreased, and all of these values decreased when the RS was added. BG was more effective in increasing the dough softening than RS. The resistance to deformation, energy, maximum resistance and ratio number values; increased with the addition of RS or BG, but their extensibility was decreased in comparison to the control. Formulation containing BG/RS combination showed the best farinograph (development time, stability) and extensograph (resistance and extensibility) parameters. The application of BG and RS had similar effect on specific volume, and moisture content while it caused a decrease in firmness after 5 days of storage.

Effect of extrusion on thermal, textural and rheological properties of legume based snack.

Attempts have been made to improve dough handling properties and quality of legume based snack by incorporating extruded black gram (EBG) flour as partial substitute for raw black gram (RBG) flour. In present work overall quality improvement was achieved by analyzing (a) thermal properties of RBG and EBG flour (b) rheological properties (shear stress, shear rate, storage modulus, loss modulus, deflection angle and complex viscosity) of legume based snack dough and (c) post frying characteristics (colour and texture) of legume based snack. Three different legume based snack samples with different flour formulations (RBG flour, RBG flour incorporated with 25% EBG flour and RBG flour incorporated with 50% EBG flour) were prepared, characterized and compared with standard market sample. Dough exhibited shear thinning behaviour and G' and G″ showed rising behaviour with angular frequency whereas, complex viscosity showed decreasing behaviour. Herschel-Bulkley model was best fitted. Significant changes were observed in values of onset, peak and endset gelatinization temperatures on extraction of black gram flour which improved dough handling properties during papad processing and enhanced organoleptic profile of end product.

The rheology of batch and continuously prepared gluten-free bread dough in oscillatory and capillary shear flow.

Reduced elasticity and high stickiness of gluten-free bread doughs are major issues regarding the industrial breadmaking process. In this work, we compared traditional batch mixing with a revised continuous extrusion process and extensively study the rheological properties of both doughs. Shear viscosities were measured offline with a capillary rheometer and inline at the extruder die over a large range of apparent shear rates. Data were corrected for entrance effects, wall slip and non-Newtonian flow behaviour. Good agreement between inline and offline measured viscosities were supplemented by amplitude and frequency sweep tests. The results highlight that this extrusion process fostered the production of gluten-free bread dough. We demonstrated that extrusion processing support the combined mixing, kneading, and moulding of gluten-free dough in one single unit. This fundamental study linked physical dough characterization with applied engineering and yielded the understanding and processing of corresponding products.

Genotype, environment, seeding rate, and top-dressed nitrogen effects on end-use quality of modern Nebraska winter wheat.

BACKGROUND: Fine-tuning production inputs such as seeding rate, nitrogen (N), and genotype may improve end-use quality of hard red winter wheat (Triticum aestivium L.) when growing conditions are unpredictable. Studies were conducted at the Agronomy Research Farm (ARF; Lincoln, NE, USA) and the High Plains Agricultural Laboratory (HPAL; Sidney, NE, USA) in 2014 and 2015 in Nebraska, USA, to determine the effects of genotype (6), environment (4), seeding rate (3), and flag leaf top-dressed N (0 and 34 kg N ha-1 ) on the end-use quality of winter wheat. RESULTS: End-use quality traits were influenced by environment, genotype, seeding rate, top-dressed N, and their interactions. Mixograph parameters had a strong correlation with grain volume weight and flour yield. Doubling the recommended seeding rate and N at the flag leaf stage increased grain protein content by 8.1% in 2014 and 1.5% in 2015 at ARF and 4.2% in 2014 and 8.4% in 2015 at HPAL. CONCLUSION: The key finding of this research is that increasing seeding rates up to double the current recommendations with N at the flag leaf stage improved most of the end-use quality traits. This will have a significant effect on the premium for protein a farmer could receive when marketing wheat. © 2017 Society of Chemical Industry.

Fractionation of unreduced gluten proteins on SEC and their relationship with cookie quality characteristics.

The size distribution assessment of unreduced wheat gluten proteins of commercial Indian wheat varieties was examined using Size-Exclusion Fast Protein Liquid Chromatography. Elution profiles were fractionated into five peaks, with the molecular weights of eluting peaks as 130-30, 55-20, 28-10 and <10 kDa (IV and V), respectively. Peak I (glutenins) and II (gliadins) exhibited contrary results with AWRC (r = 0.928** and r = -0.831**), R/E ratio (r = 0.745** and r = -0.869**), gluten index (r = 0.959** and r = -0.994**), gliadin/glutenin ratio (r = -0.952** and r = 0.948**), dough development time (r = 0.830** and r = -0.930**), dough stability (r = 0.901** and r = -0.979**) and dough weakening (r = -0.969** and r = 0.986**). Significant statistical correlation was also observed for peak I and II with cookie hardness (r = 0.948** and r = -0.924**) and cookie spread (r = -0.837** and r = -0.743**) respectively. Peak III, IV and V occupied a minor fraction of whole and did not exhibit a statistically significant correlation with any of the quality parameters.

Physicochemical characterization of white, yellow and purple maize flours and rheological characterization of their doughs.

White, yellow and purple maize flours were obtained after dried kernels milling with two different sieves (200 and 500 µm). Hygroscopic characteristics, particle size distribution, colour and total starch and damaged starch (DS) of flours were determined. Maize flour doughs were obtained by mixing of flour and water in a laboratory kneader (Mixolab®) at constant dough consistency (1.10 ± 0.07 Nm). Dough properties like water absorption (WA), development and stability times were determined. Rheological characterization was carried out at 30 °C by means of oscillatory frequency sweep (1-100 rad s(-1)) at 0.1 % strain and creep (50 Pa, 60 s) - recovery (0 Pa, 180 s) tests using a controlled stress rheometer. No significant differences were observed among water desorption isotherms of maize varieties and Halsey model was satisfactorily employed. Under the same milling conditions, white maize flours showed higher average particles size than purple and yellow maize flours. A model to predict flours colour involving colour parameters of the particle size fractions is proposed. Flours obtained with smaller particle size showed higher DS content and WA. For tested doughs, the mechanical spectra showed that elastic component was dominant over the viscous one. Damping factor varied slightly with angular frequency. Moduli values depended on average particle size and WA of dough. Creep-recovery data were satisfactorily fit with Burgers model. Instantaneous creep compliance varied with the same trend than elastic modulus. Viscoelastic creep compliance increased linearly with WA of the tested doughs and, at constant average flour particle size, increased with increasing DS.

Influence of watermelon seed protein concentrates on dough handling, textural and sensory properties of cookies.

Fruit processing wastes contain numerous by products of potential use in food & allied industry. Watermelon seeds represent a major by-product of the processing waste and contain high amount of nutritional proteins. Protein rich cereal based products are in demand due to their health promoting benefits. With this aim, wheat flour was fortified with watermelon seed protein concentrates (2.5 %, 5 %, 7.5 % and 10 % levels) to prepare cookies with desirable physical, nutritional, and textural and sensory properties. Substitution levels of 5 % and 10 % significantly (p ≤ 0.05) increased the dough stability and mixing tolerance index, however pasting properties and dough extensibility decreased considerably above 5 % substitution levels. Cookie fracture force (kg) increased significantly (p ≤ 0.05) above 5 % fortification levels. Cookie spread factor (W/T) increased from 2.5 % to 7.5 % fortification levels, further increase showed negative impact. Sensory scores of the cookies showed that protein concentrate may be added up to 7.5 % fortification levels. This study revealed that watermelon protein concentrates can be fortified with protein concentrates upto 5-7.5 % levels in cookies to improve their protein quality.

Relationship of dough thermomechanical properties with oil uptake, cooking and textural properties of instant fried noodles.

Instant noodles were prepared from fifteen diverse wheat cultivars varying widely in their flour quality and dough rheology. Dough thermomechanical parameters obtained by Mixolab and flour analytical properties were correlated with the quality of instant noodles including oil uptake, cooking quality and textural attributes. The Mixolab parameters dough development time and dough stability showed significant positive correlation with cooking time, cooked weight, overall acceptability, hardness, springiness, cohesiveness and chewiness of noodles, while negatively correlated with oil uptake and cooking loss, therefore, exhibiting a marked positive effect on quality of instant noodles. Lower protein breakdown represented by C2 torque was also positively related with overall acceptability, hardness, springiness, cohesiveness and chewiness of noodles. Stickiness/adhesiveness of noodles was revealed to be mainly conferred by falling number values (R (2 )= 0.671) and damaged starch (R (2 )= 0.523) content of wheat flour samples. Flour samples with lesser values of protein content, sodium dodecyl sulphate sedimentation volume, thermal stability of proteins, dough stability and dough development time were found to be linked with poor noodle quality. Medium strong flours performed better in noodle making, while weaker flours demonstrated poor noodle quality. Dough rheology of good noodle making flours was characterized with higher dough development time, dough stability, C2, C3, C4 as well as C5 values. Noodles with higher overall acceptability showed a more continuous and uniform protein starch matrix in comparison to the poor counterparts.

Effect of fat types on the structural and textural properties of dough and semi-sweet biscuit.

Fat is an important ingredient in baking products and it plays many roles in providing desirable textural properties of baking products, particularly biscuit. In this study, the effect of fat types on dough rheological properties and quality of semi-sweet biscuit (rich tea type) were investigated using various techniques. Texture profile and extensibility analysis were used to study the dough rheology, while three-point bend test and scanning electron microscopy were used to analyse the textural characteristics of final product. TPA results showed that the type of fat significantly influenced dough textural properties. Biscuit produced with higher solid fat oil showed higher breaking force but this was not significantly different when evaluated by sensory panel. Scanning electron microscopy showed that biscuit produced with palm mid-fraction had an open internal microstructure and heterogeneous air cells as compared to other samples.

Effects of Artemisia dracunculus powder on dough rheology and quality properties as a novel ingredient in bread formulation.

Tarragon has a great potential to be a healthy functional food ingredient thanks to its rich antioxidant, phenolic compounds, and nutrient content. The possibility of enriching bread with tarragon was investigated. For this aim, tarragon powder was used at the rates of 0, 2, 4 and 6% instead of wheat flour. In this study, the effects of substitution on the rheological properties of bread dough and color, total phenolic content, antioxidant activity, texture, sensory, and Fourier transform infrared (FT-IR) analysis of bread samples were performed. The composition of tarragon powder showed significant protein (23.16%), crude fiber (7.4%), antioxidant (48.22 ± 0.11%), and total phenolic content (511.66 ± 1.56 mg GAE/100 g). Bread samples with increased fiber and protein content were obtained by adding tarragon powder to the bread formulation. The major differences in the FT-IR absorbance spectra for the bread samples were not observed. Additionally, tarragon powder significantly increased the antioxidative properties of breads (p < 0.05). Adding up to 4% tarragon powder to the bread formulation increased the sensory scores of the breads.

Enhancing Gluten Network Formation and Bread-Making Performance of Wheat Flour Using Wheat Bran Aqueous Extract.

Wheat bran possesses diverse nutritional and functional properties. In this study, wheat bran aqueous extract (WBE) was produced and thoroughly characterized as a functional ingredient and improver for bakery application. The WBE contained 50.3% total carbohydrate, 24.5% protein, 13.0% ash, 6.7% soluble fiber, 2.9% insoluble fiber, and 0.5% ß-glucan. Notably, adding 7.5% WBE significantly increased the bread-specific volume to 4.84 cm3/g, compared with the control of 4.18 cm3/g. Adding WBE also resulted in a remarkable improvement in dough properties. The WBE-enriched dough showed increased peak, setback, breakdown, and final viscosities, along with higher storage and loss modulus. Scanning electron microscopy analysis further revealed that the WBE promoted the aggregation of protein and starch within the dough. The extractable gliadin to glutenin ratio increased with 5 and 7.5% WBE additions, compared with the control and 2.5% WBE addition. WBE did not significantly alter the starch gelatinization temperature or dough extension properties. These findings demonstrate that the inclusion of WBE in wheat flour is a promising approach for producing high-quality bread that is enriched with dietary fiber and protein.

Monitoring the Dough Properties, Quality Characteristics and Volatile Compounds of Whole Wheat Bread Made by Different Sourdough Types during Frozen Storage.

There is a need to increase the consumption of whole wheat bread (WWB) due to its health benefits by overcoming its poor technological quality and improving its sensory characteristics. In this study, sourdough bread-making and frozen dough technology were combined to provide fresh WWB at any time with better quality. Also, it was aimed to investigate the effects of three types of sourdough (type I, II, and IV) on the final quality of WWB during frozen storage (-30 °C, 14 and 28 days). The tan δ of WWB with type I sourdough was highest at the end of the frozen storage. Freezable water content was lower on day 0 for WWB with type II and IV sourdough than other bread types. No significant effect of frozen storage was observed in bread types in terms of an α helix structure, except for WWB with type I sourdough. A lower hardness increment was shown in WWB with baker's yeast and WWB with type II sourdough over 14 days of frozen storage when compared to other bread types. WWB with type I sourdough and WWB with type IV sourdough were differentiated from other bread samples in volatile compound (VC) analysis on frozen storage days 28 and 0, respectively. The frozen storage of WWB with baker's yeast and WWB with type II sourdough caused no notable changes in the VCs profile. These results suggest that a less detrimental effect of frozen storage was observed in WWB with type II sourdough, indicating a more favorable choice for producing WWB with sourdough.