Crumb Softness Research Articles

Microwave‐assisted treatment for the improvement of rice flour properties and rice flour bread quality

SummaryModification of rice flour by microwave and its effect on bread making performance was evaluated. Rice flour having two different water content (20% and 30%) were exposed to different level of microwave power (600 W, 700 W and 800 W) with 8 min treatment time to assess its influence on amylose content, thermal properties, morphological structure, functional and crystalline structural that affect bread quality. Microwave‐treated rice flour at 600 W showed notable increment in amylose content of 1.03 folds (for both 20% and 30% water content) as compared to untreated rice flour. The microwave treatment destroyed the amorphous region of the rice flour starch, whereas starch crystal structure was slightly increased after treatment. Rice flour maintained its thermal stability even after exposure to high radiation of microwave. The treated rice flour exhibited starch granules with more voids on its surface, indicating the exudation of amylose at higher temperature. The major effect of microwave treatment was observed on the bread for rice flour treated at 800 W with higher specific volume, increase in gas cells pores, softer crumb, low hardness and delayed staling as compared to untreated rice flour. The microwave‐assisted treatment shows a significant potential in improving the rice flour quality led to increase the quality of bread.

Spatial distribution of antioxidant activity in baguette and its modulation of proinflammatory cytokines in RAW264.7 macrophages

Baguette is a globally acclaimed bakery staple, composed by a crispy crust and soft crumb, both containing Maillard reaction products (MRPs) with potential bioactivities. However, MRPs’ impacts on the nutritional and health attributes of baguette, particularly in terms of cellular and biological functions, are yet to be clearly elucidated. This study chemically characterizes the crust and crumb of baguettes and investigates the influence of the Maillard reaction on baguette’s nutritional profile, especially in the antioxidant and anti-inflammatory effects. The findings indicate an increase in browning intensity and advanced glycation end products (AGEs) from the baguette’s interior to its exterior, alongside a significant rise in the antioxidant capacity of the crust, suggesting the Maillard reaction’s role in boosting antioxidative properties. Both the crust and crumb demonstrated strong cytocompatibility with immune cells, capable of reducing cellular oxidative stress and regulating intracellular free radical levels. The crust effectively countered peroxyl radical-induced cell membrane hyperpolarization by 91% and completely neutralized the suppression of oxygen respiration in mitochondria, displaying higher efficacy than the crumb. In contrast, crumb extracts were more potent in inhibiting lipopolysaccharide-induced expression of proinflammatory cytokines, such as interleukins-1β (IL-1β) and IL-6, in macrophages. It could provide the fundamental data and cell-based approach for investigating the biological impacts of bread on immune responses, contributing to the refinement and supplementation of nutritional recommendations.

Impact of Sprouted Chickpea Grits and Flour on Dough Rheology and Bread Features.

This study investigated the effects of incorporating sprouted chickpeas, at a 25% enrichment level, into bread production as either grits (90% of particles ≥500 µm) or flour (90% of particles ≤250 µm). The focus was to investigate the role of particle size on dough and bread. In addition to the functional, mixing and pasting properties of ingredients, gluten aggregation, mixing, extensional, leavening, and pasting properties of the blends were assessed during bread-making, as well as bread volume and texture. Chickpea particle size influenced water absorption capacity (1.8 for grits vs. 0.75 g/g for flour) and viscosity (245 for grits vs. 88 BU for flour), with flour showing a greater decrease in both properties. With regard to dough properties, dough development time (16.6 vs. 5.3 min), stability (14.6 vs. 4.6 min), and resistance to extension (319 vs. 235 BU) was higher, whereas extensibility was lower (105 vs. 152 mm) with grits, compared to flour. During bread-making, grits resulted in a higher specific volume (2.5 vs. 2.1 mL/g) and softer crumb (6.2 vs. 17.4 N) at all the considered storage times. In conclusion, sprouted chickpea grits can be effectively used as a new ingredient in bread-making favouring the consumption of chickpea, without compromising product quality.

Microwave-treated rice flour halves the need of hydroxypropyl methylcellulose in the formulation of gluten-free bread

Hydrocolloids such as hydroxypropyl methylcellulose (HPMC) are commonly used in gluten-free (GF) products to mimic the viscoelastic properties of gluten. However, GF products must meet current consumer expectations by not only being tasty and nutritious, but also adhering to ‘clean label’ principles, which involve minimizing ingredients and additives and favoring natural over chemical components. Modifying GF flours via hydrothermal treatments offers an alternative approach to reduce the use of additives in GF products. This work applied response surface methodology to study the potential reduction in HPMC dose in the formulation of GF-breads by the addition of microwave-treated rice flour (MWF) (treatment conditions: 8 min, 9 W/g, 30% moisture), without impairing their appearance, volume, and texture. The optimization study also included Water level and HPMC dose, and evaluated the dough's rheological properties at constant hydration. GF breads were made by varying the amount of native flour substituted with MWF, water level, and HPMC dose. Replacing 50% or 80% of native rice flour by MWF allowed to reduce the usual HPMC dose by more than half. This resulted in higher loaf volume and a softer crumb than their counterparts made with untreated flour and baked with the usual dose of additive (2%). Doses of HPMC as low as 0.7% with 80% MWF still resulted in breads with good texture and acceptable volume. Therefore, the structuring effect of MWF and its good performance in GF baking have been concluded, allowing to reduce the dose of additives required in formulating GF bread.

Functionality of pre‐cooked whole‐grain corn, rice and sorghum flours for gluten‐free bread

SummaryExtruded whole grain flours of corn, sorghum, and parboiled brown rice (PBR) and their blends were used to produce gluten‐free (GF) multigrain bread. To determine the functionality of the flours, paste viscosity, farinography and oscillatory rheometry were evaluated as rheological methods, and for the bread, the texture profile, baking loss and specific volume of the breads were determined. The paste properties evidenced changes in the starch structure of the extruded samples, but these were not severe due to the absence of cold viscosity (CV) and formation of peak viscosity (PV), which evidenced the swelling capacity of the starch granules. The functionality of the samples was demonstrated by the increase in water absorption and farinographic consistency (PM), as well as by the development of dough viscoelasticity with continuous elastic (G′) and viscous (G′′) moduli when measured by oscillatory rheometry. The GF breads produced showed specific volume increases from 53.8 to 91.7% compared to the control, as well as high crumb hardness. However, the cereal blends did not generate significant increases in specific volume between samples (P < 0.05), but those made with higher proportions of extruded sorghum flour and its blend with corn had better crumb softness and lower baking loss (P < 0.05). On the other hand, the regression models for most of the dough rheological and bread textural variables were significant and presented good coefficients of determination (R2 Adj = 0.60–0.99) with linear and quadratic fits, thus allowing prediction of the behaviours of these variables for future applications.

Sorghum (Sorghum bicolor L. Moench) Gluten-Free Bread: The Effect of Milling Conditions on the Technological Properties and In Vitro Bioaccessibility of Polyphenols and Minerals.

The absence of gluten proteins in sorghum allows for the production of baked goods that are suitable for celiacs. Previous studies have shown that the milling process affects the performance of sorghum flour in baked products, especially those that are gluten-free (GF). This study aimed to explore the effects of mill type (impact and roller) on flour properties and GF bread quality by assessing the technological quality, antioxidant activity, and mineral content of the bread. All particle populations of flour obtained via both millings presented a bimodal distribution, and the volume mean diameter (D 4,3) ranged from 431.6 µm to 561.6 µm. The partially refined milled flour obtained via polishing and impact milling produced bread with a soft crumb, fewer but larger alveoli in the crumb, and a structure that did not collapse during baking, showing the best performance in bread quality. In the in vitro bread digestibility assay, the total polyphenol content and antioxidant activity decreased during the digestion steps. High mineral (Cu, Fe, Mn, and Zn) contents were also found in a portion of the bread (120 g) made with whole sorghum flour; however, their potential bioavailability was reduced in the presence of a higher amount of bran.

Potential application of bioemulsifier RAG-1 as an anti-staling agent in flat bread quality.

Bread undergoes physicochemical processes known as 'staling', which limits shelf life and quality. Despite the fact that several chemical emulsifiers have been employed to combat this issue, they may offer risks to human health. In this investigation, the effects of bioemulsan, a natural bioemulsifier (BE), on bread quality and staleness were examined. The yield of emulsan generated by Acinetobacter calcoaceticus RAG-1 was 1.49g/L. The presence of clear zones around colonies, high emulsification value of 100%, and remaining surface tension below 40 mN/m after heating (at 250°C for 15-20min) verified emulsan thermal stability. BE-supplemented bread had a greater moisture percentage than the control, resulting in reduced crumb hardening and improved bread quality during storage as measured by moisture content. The first day after adding 0.5% emulsan, the hardness rose from 90.45 N (for the control) to 150.45 N. Texture analysis showed that although the hardness increased during storage, adding emulsan allowed obtaining bread with clearly softer crumb after 2 and 3days of baking, especially at 0.5% level (from 215.6 N for the control to 150.5 N for 0.5% BE-enriched bread after 2days, and from 425.7 to 210.25 N after 3days). Based on the sensory evaluation results, emulsan did not lead to any unpleasant changes on bread organoleptic parameters. Therefore, using bioemulsifier RAG-1 as a green emulsifier and anti-staling agent found to be more promising.

Physical modification caused by acoustic cavitation improves rice flour bread-making performance

Acoustic cavitation has been shown to cause physical damage and partial starch depolymerization in ultrasound-treated flours. However, the promising effects of this modification on bread-making performance of gluten-free flour are still unexplored. Based on this hypothesis, sonicated rice flour (2–20 min) was used to replace 30% native flour in the control formulation of gluten-free bread. Breadmaking performance was characterized by doughs' pasting, thermal, and rheological properties, and physical quality of breads. Ultrasonication time presented a direct correlation with particle fragmentation. Doughs’ rheology presented reduced tan(δ)₁ values (up to −11%) and improved recovery after the application of stress (up to +14%), denoting an enhanced elastic behavior with respect to the control dough. Rheo-fermentative tests demonstrated that ultrasonication accelerated the generation of CO2 and its retention within the dough structure, as consequence of eased accessibility of yeast to simpler sugars after starch depolymerization. The small-size particles (∼10 μm) in ultrasonicated flours seem to have enhanced their Pickering emulsifying ability and led to breads with higher specific volumes (up to 24%), softer crumbs, and delayed hardening during storage. Ultrasonication, a low-cost technology, has been shown to significantly improve the fermentative and viscoelastic behavior of rice flour dough and its breadmaking performance.

Influence of Particle Size and Xylanase Pretreatment of Proso Millet Bran on Physical, Sensory and Nutritive Features of Gluten-Free Bread.

Millet bran is a by-product rich in dietary fibre, micronutrients and bioactive compounds which are often deficient in a gluten-free diet. Previously, cryogenic grinding has been shown to improve the functionality of bran to some extent, although it offered limited benefits for bread making. This study aims to investigate the effects of adding proso millet bran depending on its particle size and xylanase pretreatment on the physicochemical, sensory and nutritional properties of gluten-free pan bread. Coarse bran (d50=223 μm) was ground to medium size (d50=157 μm) using an ultracentrifugal mill or to superfine particles (d50=8 μm) using a cryomill. Millet bran presoaked in water (for 16 h at 55 °C) with or without the addition of fungal xylanase (10 U/g) replaced 10% of the rice flour in the control bread. Bread specific volume, crumb texture, colour and viscosity were measured instrumentally. Along with proximate composition, the content of soluble and insoluble fibre, total phenolic compounds (TPC) and phenolic acids as well as total and bioaccessible minerals of bread were assessed. Sensory analysis of the bread samples included a descriptive, hedonic and ranking test. Dietary fibre content (7.3-8.6 g/100 g) and TPC (42-57 mg/100 g) on dry mass basis of the bread loaves depended on bran particle size and xylanase pretreatment. The effect of xylanase pretreatment was most evident in the loaves with medium bran size in terms of higher content of fibre soluble in ethanol (45%) and free ferulic acid content (5%), improved bread volume (6%), crumb softness (16%) and elasticity (7%), but lower chewiness (15%) and viscosity (20-32%). Bread bitterness and dark colour were increased after adding medium-sized bran but its bitter aftertaste, crust crookedness, crumb hardness and graininess were reduced with xylanase pretreatment. Although bran addition impaired protein digestibility, it enriched the bread with iron (341%), magnesium (74%), copper (56%) and zinc (7.5%). Xylanase pretreatment of the bran resulted in the improved bioaccessibility of zinc and copper of the enriched bread compared to the control and bread without xylanase. Application of xylanase to medium sized bran obtained by ultracentrifugal grinding was more successful than its application to superfine bran obtained by the multistage cryogrinding as it resulted in more soluble fibre in gluten-free bread. Moreover, xylanase was proven beneficial in maintaining desirable bread sensory properties and mineral bioaccessibility.

Papaya dietary fiber concentrates for providing functionality to muffin formulations.

Papaya leftovers are a good source of dietary fiber (DF) and antioxidants. They can be transformed in dietary fiber concentrates (DFCs) to be used as ingredients in food formulation, improving consumers' health status. Using the peel or the pulp of papaya, DFCs were produced. These DFCs were used in muffin production. Muffins produced with 7.7% DFCs and 47.6g water had the same specific volume (2.0cm3 g-1 ) but softer crumb than those obtained with a reference formulation without DF addition, showing average hardness of 15 N. In general, the addition of DFCs of pulp or peel slightly affected other textural profile parameters. Also, non-significant differences were observed for muffins containing pulp or peel DFCs, which showed average values of 10.9N for chewiness, 0.95 for springiness, 0.76 for cohesiveness and 0.42 for resilience. Regarding the crumb structure, muffins with pulp DFCs showed the lowest value for d3.2 (1.3 ± 0.3 mm). Meanwhile, the highest anti-radical and reducing capacity, 240 ± 2 and 1050 ± 6 mgeq Trolox g-1 muffin (dry basis), respectively, were observed in the muffins with peel DFC. Finally, the addition of DFCs allowed us to maintain lower hardness values than those of the reference formulation during the whole storage period studied (22 days). Muffins with peel DFCs tended to have a lower rate of crumb hardening (0.08 ± 0.02) d-1 . The addition of papaya DFCs to muffin formulations confers interesting properties for industry and consumers, providing functionality, extending the shelf life as well as transforming papaya leftovers in new functional ingredients, contributing to a circular economy. © 2022 Society of Chemical Industry.

Understanding the influence of in situ produced dextran on wheat dough baking performance: Maturograph, biaxial extension, and dynamic mechanical thermal analysis

Rheological tests performed under conditions relevant to those experienced during proof and oven rise are necessary for understanding the mechanisms of dextran addition on wheat dough baking performance. This study evaluated the effect of a high molecular weight ( Mw ) dextran, produced in situ by Weissella confusa A16 or externally added, on wheat dough rheological properties including, (i) proofing behavior using a maturograph; (ii) bi-axial extensional profile using a dough inflation system; and (iii) viscoelastic characters (proof) and thermo-mechanical properties (simulated baking) by dynamic mechanical thermal analysis (DMA). The externally-added dextran increased dough elasticity, tenacity, and viscoelastic characters, but reduced dough extensibility at bubble rupture. DMA tests of doughs under dynamic heating conditions showed a sharp increase of elastic and loss moduli until maximum between 75 and 95 °C, accompanied by a drastic decrease of Tan δ (dough stiffening). Dextran addition exhibited a weakening effect on the dough thermal properties i.e., decreased peak moduli during heating. On the other hand, the mild acidic conditions during sourdough fermentation favored the activity of in situ produced dextran, conferring significantly improved thermal-mechanical properties and dough extensibility. This may explain the superior ability of in situ produced dextran to improve bread volume and crumb softness compared to the external-added dextran. By analyzing rheological parameters, we showed that the maximum proofing moduli in DMA, fermentation stability, dough level, and elasticity in maturogram were predictors of good baking quality. Overall, our study provides the mechanistic underpinning and optimum of dextran as a natural improver of bread quality. • Rheological properties of doughs are strongly associated with baking performance. • Dextran increases dough elasticity and tenacity but reduces dough extensibility. • Dextran added externally exhibits a thermal weakening effect on wheat dough. • Dextran produced in situ is preferred in improving dough rheology and bread quality. • Favorable effects of in situ -produced dextran are mediated by mild acidification.

Comparative study of soluble soybean polysaccharides on bread staling under acidic conditions

Effect of soluble soybean polysaccharides (SSPS) and acidic condition on the bread staling of crumb and crust were evaluated in bread characteristics, water migration, starch retrogradation, and flavor. Bread characteristic analysis showed SSPS and acidic conditions significantly improved bread quality during storage, maintaining crumb softness. The staling rate of the synergistic group under SSPS and acidic condition decreased by 49.46% compared to the control group. This retardation was associated with water migration and starch retrogradation. SSPS and acidic conditions restricted the water migration from crumb to crust. A synergy between SSPS and acidification restrained the relative crystallinity and retrogradation enthalpy in bread crumbs and crust during storage. The scores plot and heat map analysis indicated SSPS and acidic condition was facilitated the flavors retention in the crumb and crust after stored 7-days. This study suggested SSPS and acidic conditions might be beneficial for extending bread shelf-life.

Effect of Freezing Wheat Dough Enriched with Calcium Salts with/without Inulin on Bread Quality.

Bread is a popular food that is widely consumed worldwide but has a short shelf life. Besides that, when incorporating prebiotics and calcium, aging mechanisms accelerate, further shortening the shelf-life. The objective of this work was to evaluate the effect of freezing storage on the rheological (loss tangent, tan δ) and thermal (glass transition temperature, Tg) properties of unfrozen dough, the fermentation times (tf), and the baking quality of wheat bread fortified with calcium and inulin. Formulations studied included wheat flour (control-C), flour with 1800 ppm Ca (calcium carbonate-CA, calcium citrate-CI or calcium lactate-LA), and flour with 2400 ppm Ca and 12% inulin (calcium carbonate-CA-In, calcium citrate-CI-In or calcium lactate-LA-In). Doughs were stored at −18 °C for 1, 7, 30 and 60 days. After storage, the rheological (oscillatory rheometry and texture profile analysis) and thermomechanical properties of the thawed doughs were measured. The quality parameters of breads determined consisted of specific volume (Vs), color, moisture, firmness, elasticity, and alveoli size characterization. Dough freezing neither changed viscoelasticity (tan δ) nor decreased hardness and adhesiveness up to the values observed for fresh wheat dough. The Tg of dough with calcium carbonate increased, while for samples with organic calcium salts, it (citrate and lactate) decreased. The tf of thawed dough significantly increased. The Vs of all breads did not change during the first 30 days but decreased after freezing the dough for 60 days (p < 0.05), probably due to the death of the yeasts. Crumb moisture decreased over time, and in all cases crumb C had the highest moisture content, suggesting a dehydration effect of the calcium salt. The firmness of CA, LA and C crumbs were similar and higher than that of CI (p < 0.05), suggesting a destabilizing effect of CI anion on gluten proteins. Inulin contributed to the depreciation of bread quality, mainly at 60 days of dough freezing storage. It can be concluded that during freezing storage, calcium improves the dynamic elasticity of the dough, although under extreme conditions it generates loaves of smaller volume. Principal component analysis (PCA) explained 66.5% of total variance. Principal component 1 (PC1) was associated with dough properties, and accounted for 44.8% of the total variance. In turn, PC2 was mainly related to baking quality parameters (fermentation time, browning index, firmness and springiness of crumbs), and explained 21.7% of the total variance. Fortification with calcium citrate should be recommended for dough freezing, as breads with softer crumbs were obtained under such conditions.

Recombinant Rice Quiescin Sulfhydryl Oxidase Strengthens the Gluten Structure through Thiol/Disulfide Exchange and Hydrogen Peroxide Oxidation.

Recombinant rice quiescin sulfhydryl oxidase (rQSOX) has the potential to improve the flour processing quality, but the mechanisms remain unclear. The effects of rQSOX on bread quality, dough rheology, and gluten structure and composition, with glucose oxidase as a positive control, were investigated. rQSOX addition could improve the dough processing quality, as proved by enhanced viscoelastic properties of dough as well as a softer crumb, higher specific volume, and lower moisture loss of bread. These beneficial effects were attributed to gluten protein polymerization and gluten network strengthening, evidenced by the improved concentration of SDS-insoluble gluten and formation of large gluten aggregates and the increased α-helix and β-turn conformation. Furthermore, decreased free sulfhydryl and increased dityrosine in gluten as well as improved H2O2 content in dough suggested that the rQSOX dough strengthening mechanism was mainly based on the formation of disulfide bonds and dityrosine cross-links in gluten by both thiol/disulfide direct exchange and hydrogen peroxide indirect oxidation pathways.

Dry Heating of Cowpea Flour below Biopolymer Melting Temperatures Improves the Physical Properties of Bread Made from Climate-Resilient Crops.

Improving the technological functionality of climate-resilient crops (CRCs) to promote their use in staple foods, such as bread, is relevant to addressing food and nutrition security in Africa. Dry heating of cowpea flour (CPF) was studied as a simple technology to modulate CPF physicochemical properties in relation to bread applications. For this purpose, the melting behavior of cowpea starch and proteins in CPF was first studied and modeled using Flory–Huggins theory for polymer melting. Next, dry-heating conditions were investigated based on the predicted biopolymer melting transitions in CPF to be well below starch and protein melting. The pasting properties (i.e., peak viscosity, final viscosity, breakdown and setback) of CPF could be selectively modulated depending on temperature-time combinations without altering the thermal behavior (i.e., melting enthalpies) of CPF. Water-binding capacity and soluble solids decreased with the increased severity of the temperature-time combinations. Dry-heated CPF added to CRC-based bread significantly improved crumb texture. In particular, dry heating at 100 °C for 2 h provided bread with the highest crumb softness, cohesiveness and resilience. The positive effects on the crumb texture could be largely related to enhanced starch integrity, as indicated by a reduction in breakdown viscosity after treatment. Overall, dry heating of CPF under defined conditions is a promising technology for promoting the use of CPF as a techno-functional and protein-rich ingredient in bread-type products.

In situ production of vitamin B12 and dextran in soya flour and rice bran: A tool to improve flavour and texture of B12-fortified bread

This study aimed to develop a fermentation process that allows the concomitant production of dextran (a texture-enhancing agent) and vitamin B12 (in situ fortification) for bread applications. Mixed fermentation of soya flour or rice bran using Propionibacterium freudenreichii DSM 20271 and Weissella confusa A16 with added sucrose resulted in substantial quantities of dextran (5.6–5.8% dry matter) and B12 (7.9–8.9 μg/100 g fresh weight), together with antifungal metabolites (e.g. acetic and propionic acids). In addition to an extended mould-free shelf life, the bread containing 50% (dough weight) fermented soya flour or rice bran not only contained adequate levels of B12 but also exhibited improved texture and sensory quality compared to the control, such as a higher loaf volume, a softer crumb, and a more cohesive and moister mouthfeel. The mixed fermentation reduced the beany or cooked-rice flavour but increased sour and cheesy flavours and aftertaste. Dextran produced during the fermentation process exhibited a masking effect on the beany and sour notes and aftertaste, consistently with reduced levels of green or grassy volatiles (e.g. hexanal, heptanal, (E,E)-2,4-decadienal, and 2-pentylfuran). Overall, the mixed fermentation method using P. freudenreichii DSM 20271 and W. confusa A16 showed potential for B12 fortification of bread products with high sensory quality.

Defining Amaranth, Buckwheat and Quinoa Flour Levels in Gluten-Free Bread: A Simultaneous Improvement on Physical Properties, Acceptability and Nutrient Composition through Mixture Design.

The study aimed to define the ideal proportions of pseudocereal flours (PF) in sensory-accepted gluten-free bread (GFB) formulations. The characteristics of GFB developed with PF (amaranth, buckwheat, and quinoa) were verified through a mixture design and response surface methodology. Three simplex-centroid designs were studied to analyze the effects of each PF and their interactions with potato starch (PS), and rice flour (RF) on GFB’s physical and sensory characteristics, each design producing three single, three binary and six ternary GFB formulations. Results showed that using PF alone resulted in unacceptable GFB. However, the interactions between PF and RF improved the loaf specific volume and the crumb softness and also enhanced appearance, color, odor, texture, flavor, and overall liking. Moreover, the composite formulations prepared with 50% PF and 50% RF (flour basis) presented physical properties and acceptability scores like those of white GFB, prepared with 100% RF or a 50% RF + 50% PS blend (flour basis). Maximum proportions of PF to obtain well-accepted GFB (scores ≥7 for all evaluated attributes on a 10-cm hybrid hedonic scale) were defined at 60% for amaranth flour (AF), 85% for buckwheat flour (BF), and 82% for quinoa flour (QF) in blends with RF.

The influence of fermented buckwheat, quinoa and amaranth flour on gluten-free bread quality

In this study, buckwheat, quinoa and amaranth flours were fermented by two different methods (spontaneous fermentation and yeast fermentation) and fermented dough of pseudocereals (PFD) was used (0, 15, 30 and 45%) in gluten-free bread formulation. The effects of PFD and fermentation methods of pseudocereals on bread quality were investigated. The increase in the PFD ratio enhanced the amounts of ash, crude protein, total phenolic content (TPC) and antioxidant activity (AA) of breads samples. Among the pseudocereals, quinoa revealed the highest TPC and AA values in the bread samples. The high ratio of PFD (45%) increased the Ca, P, K, Fe, Mg and Zn content of gluten-free breads by 1.3–4.3 times. Although breads with fermented dough of amaranth received high scores in terms of symmetry, pore structure and appearance, they were less appreciated by consumers in terms of taste-odor. Fermentation of pseudocereals using bakers’ yeast yielded in softer crumb in the bread samples. Breads containing PFD produced by spontaneous fermentation scored less in sensory analyses. It was concluded that acceptable quality gluten-free bread can be produced with the use of up to 30% PFD.

Potential of a Techno-Functional Sourdough and Its Application in Sugar-Reduced Soft Buns

Functional lactic acid bacteria (LAB) as starter cultures used in sourdough fermentation have been researched for years. This study evaluated the LAB strains Leuconostoc citreum DCM65 (mannitol, exopolysaccharide producing, antifungal activity) and Lactiplantibacillus plantarum subsp. plantarum MA418 (amylolytic activity) and their potential as single or co-culture starters in sourdough fermented buns containing different levels of sugar (control 9% and reduced 0, 3, 6%). Cell counts, pH development, and organic acids were determined before and after sourdough fermentation (30 °C, 24 h) and physical properties (color, volume, pore structure, and texture) of buns produced thereof were determined after baking. Sourdoughs started with DCM65 and/or MA418 developed up to log 9.2 CFU/g presumptive LAB after 24 h, assertiveness of the added starter cultures species was confirmed by MALDI-TOF MS. Acetic acid and mannitol were only detected in sourdough fermented with DCM65 (single or co-culture) up to 2.5 mg/g and 9.8 mg/g, respectively. The starter cultures applied influenced physical properties of buns. Sourdough buns started with MA418 had higher volume and slice area, and softer crumb; in contrast, buns fermented with DCM65 had a finer pore structure. In summary, both starter cultures showed high potential in sourdough buns with reduced sugar content.

Effect of black rice flour with different particle sizes on frozen dough and steamed bread quality

SummaryThis article presents a novel idea for the preparation of frozen dough and steamed bread by which black rice flour (BRF) with different particle sizes (0.18–0.25 mm, 0.15–0.18 mm and 0.125–0.15 mm) was added into wheat flour (WF), considering the nutritional values of BRF. The characteristic of the composite flour (CF), frozen dough and steamed bread was studied. CF had higher contents of dietary fibres (2.01–2.16%) but lower content of protein (11.57–11.92%) compared with WF (1.6% and 12.60%, respectively). Correlation analysis showed that the addition of BRF could alleviate the damage to dough caused by freezing, which may be due to that water in CF dough was more stable. The content of freezable water in WF dough increased by 23.48%, while that in CF dough increased by 6.09–12.11% after frozen storage. With decreasing particle size, the hardness of CF dough decreased and the resistance to extension and gas retention coefficient increased, whereas the specific volume and the soft crumb texture of CF steamed bread increased. In short, small‐sized BRF is more suitable for use in the preparation of steamed bread.