Effects of wheat sourdough process on the quality of mixed oat-wheat bread

The aim of this work was to study the effects of sourdough fermentation of wheat flour with Lactobacillus plantarum, on the quality attributes of mixed oat-wheat bread (51 g whole grain oat flour and 49 g/100 g white wheat flour). Emphasis was laid both on β-glucan stability as well as bread structure and sensory quality. The variables of the sourdough process were: dough yield (DY), fermentation time, fermentation temperature, and amount of sourdough added to the bread dough. The sourdough process was shown to be a feasible method for mixed oat-wheat bread, and, when optimized, provided bread quality equal to straight dough baking. A small amount (10g/100 g dough) of slack sourdough fermented at high temperature for a long time resulted in the most optimal sourdough bread with the highest specific volume (3.5 cm³/g), the lowest firmness after 3 days storage (0.31 kg), and low sensory sourness with high intensity of the crumb flavour. Wheat sourdough parameters did not affect the content of oat β-glucan in the bread. Additionally, both straight dough and sourdough bread contained 1.4-1.6 g β-glucan/100 g fresh bread. The average molecular weight of β-glucan was 5.5 × 10⁵ in both types of bread, while that of oat flour was 10 × 10⁵. This indicates that a slight degradation of β-glucan occurred during proofing and baking, and it was not affected by variation in the acidity of the bread between pH 4.9-5.8.     

Bread fortified with dietary fibre extracted from culinary banana bract: its quality attributes and in vitro starch digestibility

The effect of fortification of dietary fibre (DF) on dough rheology, quality characteristics and in vitro starch digestibility of bread was studied. Bread was prepared incorporating DF (2–4 g per 100 g of flour mixture). Rheological study of dough showed an increase in dough stiffness and elasticity with higher incorporation of the DF. The results of chemical composition revealed that addition of DF increased total DF (19.65 g per 100 g) content of bread. However, incorporation of 2 g per 100 g DF of flour mixture with 66 g per 100 g moisture showed higher water retention and specific volume of 86.76% and 5.83 cm³ g⁻¹, respectively, which was close to control bread. Improved textural property with acceptable sensory attributes was observed for bread fortified with 2 g per 100 g DF of flour mixture and 66 g per 100 g moisture content. Incorporation of DF (2–4 g per 100 g of flour mixture) showed a decrease in rapidly digestible starch (RDS) and an increase in slowly digestible starch (SDS) content with lower predicted glycaemic index (pGI) than control bread.     

Effect of heat treatment of rye flour on rye‐wheat steamed bread quality

To study the effect of heat treatment on rye flour quality, rye flour was treated by steaming, high temperature and high pressure (HTHP) and extrusion and then the pasting properties of rye flour and rye‐wheat blend, the dough rheological and steamed bread (respectively, fermented by yeast and Chinese traditional starter – Laomian) making properties of rye‐wheat blend were investigated. All three kinds of heat treatment increased the viscosity of rye flour, with the peak viscosity value followed the order 1744 cP (by steaming) >823.5 cP (by HTHP) >669 cP (by extrusion) > 626.5 cP (untreated). Dough and gluten made from mRFh (HTHP‐treated rye flour and wheat flour blend) had higher storage modulus (G′) and loss modulus (G″), which contributed to better extensibility and deformation capability. Steamed bread fermented by Laomian (LSB) made by mRFh had larger specific volume (2.26 mL g^?1), lower hardness (3510.93 g) and higher sensory scores (82.63), comparable to the quality of control samples, indicating the feasibility of adding rye flour into wheat flour for healthy product development without compromising the taste and texture.     

藜麦粉对冷冻面团特性及其面包品质的影响

将藜麦和小麦粉按一定比例混合,用快速粘度分析法测定混合粉糊化特性,流变仪测定了冻藏过程中小麦-藜麦冷冻面团的流变学特性,核磁共振法测定面团中水分迁移,并测定其发酵体积变化,最后分析了冷冻面团组织状态与产品品质的关系。结果表明：藜麦粉对冷冻面团及面包的品质均有改善。藜麦粉降低了混合粉体系的糊化粘度和崩解值。冻藏后,冷冻面团的弹性模量和粘性模量增加,小麦粉冷冻面团损耗角正切值增加了4.73%,添加量为5%时冷冻面团损耗角正切值仅增加0.41%;小麦冷冻面团自由水上升了3.90%,藜麦添加后仅上升2.40%,可见藜麦粉能冷冻面团降低水分迁移程度;同时,添加藜麦粉能维持面团面筋网络结构的完整性,发酵体积由26.42 mL/h增大到29.17 mL/h。不同添加量的藜麦粉对面团及面包的品质改善程度不同,最适添加量为10%,烘烤后面包比容为3.08 mL/g,硬度为2803.48 g。本研究可为开发藜麦冷冻面团提供理论基础,在藜麦新产品开发方面具有重要的指导意义。     

Evaluation of baking procedures for incorporation of barley roller milling fractions containing high levels of dietary fibre into bread

BACKGROUND: Roller milling of hull‐less barley generates fibre‐rich fractions (FRF) enriched in non‐starch polysaccharides from the endosperm cell walls (β‐glucans and arabinoxylans). This investigation was initiated to compare the suitability of different baking processes and to determine the optimal conditions for incorporation of barley FRF into pan bread. RESULTS: Addition of FRF from waxy and high‐amylose starch hull‐less barley genotypes was evaluated in pan bread prepared from Canada Western Red Spring (CWRS) and Canada Western Extra Strong (CWES) wheat flour. Three bread processes were used: Canadian short process (CSP), remix‐to‐peak, and sponge‐and‐dough. Addition of 20% FRF (equivalent to enrichment with 4.0 g of arabinoxylans and β‐glucans per 100 g of flour) disrupted dough properties and depressed loaf volume. CSP was not suitable for making FRF‐enriched bread because dough could not be properly developed. FRF‐enriched remix‐to‐peak bread was better, especially for the stronger CWES flour. The better bread quality compared to CSP was probably due to redistribution of water from non‐starch polysaccharides to gluten during fermentation prior to remixing and final proof. The sponge‐and‐dough process produced the best FRF‐enriched bread because of the positive effect of sponge fermentation on gluten development and hydration. FRF was added at the dough stage to fully developed dough. CONCLUSION: The method of bread production strongly influences bread quality. Pre‐hydration of FRF improved bread quality. CWRS and CWES flour produced comparable FRF‐enriched sponge‐and‐dough bread. Addition of xylanase to the sponge‐and‐dough formula improved the loaf volume, appearance, crumb structure and firmness of FRF‐enriched bread. Copyright © 2007 Society of Chemical Industry     

Exploitation of lettuce waste flour to increase bread functionality: effect on physical,nutritional, sensory properties and on consumer response

Phenol and fibre‐rich flour obtained by air‐drying and grinding of lettuce waste was partially substituted (26, 53, 170 and 575 g kg^?1) to wheat flour to produce functional bread. The addition of flour progressively decreased dough leavening capacity while increased bread moisture and firmness. Lettuce waste flour significantly increased the polyphenolic content (up to 3.4 g GAE kg^?1) of bread samples and enhanced their antioxidant activity by 200%. Bread containing 170 and 575 g kg^?1 of lettuce waste flour presented sensory properties and consumer acceptability comparable to those of commercial wholemeal bread with similar rye bran content. Bread containing at least 170 g kg^?1 of lettuce waste flour could be associated to nutritional claims related to its enhanced fibre content (>30 g kg^?1). Data obtained by conjoint analysis demonstrate the possibility of increasing consumer preference for lettuce waste flour bread by proper nutritional (fibre content) and sustainability (lettuce waste valorisation) claims.     

Factors affecting 3D printing and post-processing capacity of cookie dough

This study aimed to investigate the factors affecting the printability and post-processing capacity of cookie dough in extrusion-based three-dimensional (3D) printing by modifying the recipe without the addition of gums or stabilizers. Cookie dough formulations with different types of fat (butter and shortening), flour (wheat, rice, and tapioca), the amount of non-fat milk (32.5 or 65 g/100 g flour), and the sugar level (37.5 or 55 g/100 g flour) were investigated for their printability and post-processing capacity. Rheological properties, microstructure, and printability of printing inks were monitored while the moisture loss and dimensional stability after baking were analyzed in printed and baked structures, respectively. Results indicated that cookie dough formulations with reduced sugar content were more printable. The best sample to build a shape that could withstand the baking process was the recipe of 37.5 g sugar, 62.5 g shortening, 100 g tapioca flour, and 32.5 g milk, which yielded printed cookie samples with the ease of printing, better visual printing outcomes, and no structural deformation after baking.Industrial relevance3D food printing is an emerging technology with many potential applications in the food industry. It is important to understand the effects of key components of food materials on the printing, which enable a wider range of structures just using a single nozzle, and provide tailored nutrition and personalization in extrusion-based 3D printing. Understanding the effects of food processing on 3D printed food items is critical to broadening its applications. This study selected cookie dough as a model system to investigate the 3D food printing since it is mainly composed of fat, sugar, flour, and milk that are the most common ingredients in many food products. Establishing knowledge of the interactions between different food components and contribution of each individual ingredient may help develop a guideline for extrusion-based 3D food printing. In addition, the results acquired from this study can fill knowledge gaps regarding the role of cookie dough component in 3D printing and their effects on post-processing of 3D printed foods.     

Enrichment of Egyptian ‘Balady’ bread. Part 1. Baking studies,physical and sensory evaluation of enrichment with decorticated cracked broadbeans flour (Vicia faba L.)

Physical, rheological and baking properties of decorticated cracked broadbeans‐wheat composite flours were studied and the acceptability of the Egyptian ‘Balady’ bread was evaluated by sensory tests. Decorticated cracked broadbeans flour (DCBF) was used to replace 5%, 10%, 15% and 20% of the wheat flour (WF) in bread. Farinographic studies showed that water absorption, arrival time and dough development time increased as the amount of DCBF increased, while dough stability time increased at 5% and 10% of DCBF substitution and decreased at 15% and 20% substitution. Also, the extensographic energy of the dough decreased as DCBF substitution increased, while the ratio between resistence and extensibility increased. There was a decrease in peak viscosity with increased amounts of DCBF. A reduction of the diameter and weight of bread loaf was observed as the amount of DCBF increased. The sensory properties of ‘Balady’ bread showed that at the two levels of 5% and 10% DCBF‐substitution, the ‘Balady’ loaves did not show any significant differences (P > 0.05). It is concluded that the replacement of bread flour (WF) with up to 10% decorticated cracked broadbeans flour produced acceptable Egyptian ‘Balady’ bread.     

Utilization of sprout‐damaged wheat as raw material for sour dough pre‐ferments with mixed cultures of lactic and propionic acid bacteria

The utilization of sprout‐damaged wheat flour in pre‐fermentation for sour dough bread‐baking increased lactic acid formation and titratable acidity several fold in comparison to the use of baker's wheat flour, and also resulted in a lactic acid to acetic acid molar ratio acceptable for sour dough bread. Further, enzymic treatment of the sprout‐damaged wheat flour with malted grain flour appared to be necessary for a properly balanced acid formation although the α‐amylase activity of sprout‐damaged wheat flour was quite high. The accumulation of lactic acid in the pre‐ferment decreased in the presence of yeast, and thus the molar ratio of lactic to acetic acid could be adjusted suitable for sour bread‐baking even with homofermentative lactic acid bacteria. Finally, when using mixed culture pre‐ferments of Lactobacillus brevis and Propionibacterium jensenii, at least 0.1% of propionic acid (based on flour weight), sufficient to prevent mold growth in the final bread, was obtained.     

Experiments on dough rheology to improve screening of bread wheat cultivars

The bread‐making potential of flour may be roughly estimated by dough rheology, especially its tolerance to over‐mixing as determined with the farinograph. The objective of this study was to identify the relative effects of experimental conditions likely to affect dough mixing stability: mixer speed, temperature, salt, yeast and bread additives such as ascorbic acid and preservatives. The addition of 1–2% salt or ascorbic acid (50 mg kg^?1 flour) improved dough mixing stability and counteracted the negative effect of bread preservatives. Mixing salted dough at slow speed (63 rpm) and 25 °C might be a more realistic bread‐making procedure for performing dough rheology assays with equipment such as the farinograph, compared to official methods (only flour and water, no salt; 30 °C). Amongst five bread wheat cultivars, differences existed in dough strengthening response to both salt and ascorbic acid, a property that may find application in wheat breeding and screening.     

A comparison of the ability of several small and large deformation rheological measurements of wheat dough to predict baking behaviour

The rheological characteristics of twenty wheat flour samples obtained from four organic flour blends and a non-organic control were compared in relation to their ability to predict subsequent loaf volume in the baked bread. The flour samples considered had protein contents that varied between 11–14 g/100 g. Four different rheological methods were employed. Oscillatory stress rheometry on the protein gel extracted from the wheat flour, oscillatory stress rheometry and creep measurement on undeveloped dough samples and biaxial extensional measurements on simple flour–water doughs. None of the fundamental rheological parameters correlated with loaf volume. There was a correlation between the storage modulus of the gel protein and storage modulus for the undeveloped dough (r = 0.85). There was a weak negative correlation between protein content and biaxial extensional viscosity (r = −0.62). Stepwise multiple regression related loaf volume to dough stability time (measured on the Farinograph) and tan (phase angle) for the undeveloped dough samples (overall model r² = 0.54). The results indicate that the four rheological tests considered could not be used as predictors of subsequent loaf volume when the bread is baked.     

Effect of waxy flour blends on dough rheology and bread quality

Although much research has been conducted on wheat flour dough rheology, the principal focus has been the role of the protein fraction. Starch is the main component of flour and plays a key role in dough dynamic properties, particularly during heating. This study assesses the effect of two different waxy flours, a durum and a bread wheat, and their blends with commercial bakers' flour on dough rheology during heating with a concurrent investigation into baking performance. Both waxy flour blends produced similar effects on dough rheological behaviour despite differences in protein content, acting to delay gelatinisation and reduce storage modulus. The main effects in bread were to increase loaf expansion during baking and reduce loaf firmness. It is postulated these effects are largely water mediated, with the higher swelling ability of the waxy starch granules reducing overall water availability and driving complete gelatinisation to higher temperatures.     

Arabinoxylan content and characterisation throughout the bread‐baking process

End‐use quality of wheat (Triticum aestivum L.) is influenced in a variety of ways by nonstarch polysaccharides, especially arabinoxylan (AX). The objective of this study was to track total and water‐extractable AX (TAX and WEAX, respectively) throughout the bread‐baking process, using wholemeal and refined flour. The TAX and WEAX content and the ratio of arabinose: xylose were assessed in flour, mixed dough, proofed dough and the bread loaf, which was separated into crumb, upper crust and bottom crust. Changes in TAX during the baking process differed between the refined flour and wholemeal samples, suggesting a change in the TAX availability which we ascribe to molecular interactions and heat treatment. WEAX content dramatically decreased during baking, suggesting that oxidative cross‐linkages rendered it unextractable. Higher levels of WEAX and lower levels of arabinose substitution were correlated with higher loaf volumes for refined flour among the hard wheat varieties. Having a better understanding of the importance of both WEAX content and arabinose substitution allows for directed breeding efforts towards improved hard wheat varieties for optimum bread baking.     

Effect of flaxseed flour addition on physicochemical and sensory properties of functional bread

The importance of polyunsaturated fatty acids (PUFA) in health and nutrition is well recognised. Flaxseed (Linum usitatissimum) has recently gained a lot of attention as functional food because of its unique nutrient profile. In the present work efforts were made to develop omega-3 enriched functional bread using raw and roasted ground flaxseed flour. Initially optimisation of each bread ingredient viz., salt, sugar, and shortening, GMS, yeast and water was carried out on the basis of sensory overall acceptability score. The standardised bread was incorporated with raw and roasted ground flaxseed (5, 10, and 15 g/100 g) flour. The effect of flaxseed incorporation on bread dough rheology parameters viz., dough stickiness and water absorption was studied. Increase in water absorption and dough stickiness was observed with increased flaxseed level. Further breads were evaluated for sensory parameters, colour and texture. The crumb softness increased with increase in flaxseed level. Bread was optimised at 10(g/100 g) flaxseed level based on sensory evaluation.     

Effect of hydroxypropyl methylcellulose,whey protein concentrate and soy protein isolate enrichment on characteristics of gluten‐free rice dough and bread

Due to a lack of gluten, rice dough needed some additives to improve its properties. This study aimed to investigate effect of hydroxypropyl methylcellulose (HPMC), whey protein concentrate (WPC) and soy protein isolate (SPI) on rice dough and bread. HPMC increased water absorption of the rice dough (P ≤ 0.05). Adding SPI (2–4 g per 100 g flour) together with HPMC tended to increase stability time and reduce tolerance index. During fermentation, HPMC increased maximum dough height, while SPI increased final dough height (P ≤ 0.05). All addition improved tan δ (G″/G′) to be comparable to the wheat dough, but it could not improve gas production and retention. Therefore, specific volume, springiness, cohesiveness and chewiness of rice bread were lower than those of wheat bread (P ≤ 0.05). Percentage of small pores in rice bread was reduced to be comparable to wheat bread, by adding WPC. All addition could improve porosity of the rice bread.     

Significance of healthy viscous dietary fibres on the performance of gluten‐free rice‐based formulated breads

The impact of associated viscous dietary fibres (hydroxypropylmethylcellulose semi‐firm – SFE‐ and weak – NE‐gel forming, and barley ß‐glucan, BBG) incorporated at different amounts (1.6–7.5%, flour basis) into gluten‐free rice‐based dough formulations on the breadmaking performance and staling behaviour of hydrated (70–110%, flour basis) fibre‐flour composite blends has been investigated. Single BBG addition fails to mimic gluten visco‐elasticity properly, but simultaneous incorporation of either SFE or NE contributes to bread improvement in terms of bigger volume and smoother crumb. 3.3 g of BBG (70% purity) and 104 mL of water addition to 100 g rice flour provided sensorially accepted breads (7.6/10) with a theoretical ß‐glucan content of 1.24 g per 100 g GF bread that would allow a daily ß‐glucan intake of 3 g provided a bread consumption of 240 g day^?1. Complementary tests should be carried out to know the amount and molecular weight of ß‐glucan in the final bread before assuring the nutritional benefit of this addition.     

Rheological and baking properties of cowpea and wheat flour blends

Effect of blending 50 to 250 g kg⁻¹ cowpea flour in wheat flour on rheological, baking and sensory characteristics of bread, chapati, cookies and muffins was studied. Farinograph water absorption, dough development time, mixing tolerance index and dough stability increased significantly with increased amount of cowpea flour. Incorporation of cowpea flour lowered gelatinisation time and peak viscosity. Loaf volume and overall acceptability scores of bread were reduced significantly beyond 150 g kg⁻¹ incorporation of cowpea flour. There were significant changes in specific volume and overall acceptability scores of muffins, registering an initial improvement up to 50 g kg⁻¹ and a significant decline thereafter. © 1999 Society of Chemical Industry     

Effect of flaxseed and wheat flour blends on dough rheology and bread quality

The rheological and baking properties of flaxseed/wheat composite flours were studied. Flaxseed flour was used to replace 50, 100, 150 and 200 g kg^?1 of wheat flour in bread. Farinographic studies showed that water absorption, dough development time and mixing tolerance index increased as the amount of flaxseed flour increased, while dough stability decreased at 100, 150 and 200 g kg^?1 of flaxseed flour substitution. The extensographic energy of dough also decreased at 150 and 200 g kg^?1 flaxseed levels. The addition of increasing amounts of flaxseed flour caused a decrease in extensibility. Doughs containing 100, 150 and 200 g kg^?1 flaxseed flour showed resistance to extension comparable to that of control dough. The specific volume of flaxseed flour breads was similar to that of control bread. Crust L, a, b values of breads with flaxseed flour were lower than those of control bread. Breads with flaxseed flour gave lower crumb L and b values and higher a values than control bread. The sensory properties showed that an acceptable bread could be produced using flaxseed flour up to a level of 200 g kg^?1. Copyright © 2007 Society of Chemical Industry     

Utilization of germinated ancient wheat (Emmer and Einkorn) flours to improve functional and nutritional properties of bread

Germinated and untreated ancient (Einkorn and Emmer) and modern (Esperia) wheat flours (0, 5, 10, 15 and 20%) were used in bread dough to improve functional and nutritional properties of bread according to (3 × 2 × 5) x 2 factorial design. Utilization of wheat varieties in the germinated form increased the ash, total dietary fiber (TDF), total yellow pigment (TYP), total phenolic content (TPC), antioxidant activities, Ca, Fe and Mg content of bread, and also the most increments in those values (except TYP) were observed in Emmer flour usage. Germinated wheat flour decreased the mean phytic acid contents of bread samples from 313.32 mg/100 g to 291.81 mg/100 g compared to untreated wheat flour. The use of ancient wheat flour (einkorn and emmer) gave lower bread volume compared to modern bread wheat flour. The use of germinated wheat flour decreased the crust and crumb L* values of the breads but increased the a* and b* values. As a result, increasing ratios of germinated ancient wheat flour increased the functional component and nutritional value of the bread, and at the same time, its usage at low ratio contributed positively to the technological quality of the bread.     

Impact of wheat bran addition on the temperature‐induced state transitions in dough during bread‐baking process

Wheat bran‐mediated effects on temperature‐induced state transitions of proofed bread dough were studied as function of its level of replacement (5%–15%) to wheat flour. Proofed dough was subjected to rheological tests at small deformations. During heating of proofed dough from 30 °C to 95 °C, the value of elastic modulus (G′) attained its maximum at a temperature () that represented peak gelatinisation temperature (T_P). Dough with 15% bran depicted significant increase in T_P over other formulations. Bran addition increased glass transition temperature (T_g) of dough and suppressed drop in elastic modulus (G′) at T > T_g. The above events resulted in decreased loaf‐specific volume and increased crumb hardness. The former was caused by retarded bubble expansion during initial stages of baking, explained by reduced uniaxial and biaxial extensibilities of dough. Mean bubble size depicted an inverse relationship with the hardness of breadcrumb.