Impact of process conditions on the structure of pre-fermented frozen dough

The volume change of partially fermented dough exposed to refrigeration has been investigated. Lean dough pieces (70 g) were exposed to pre-fermentation at 30 °C during selected time to reach expansion ratios of 2, 3 and 4. The pre-fermented dough were exposed to cooling at 4 °C for 2 h. Dough pieces were then frozen, thawed and baked. The evolution of the volume of the dough during the different stages of the time-temperature history has been measured. Image analysis (cell distribution), of both pre-fermented dough in frozen state and baked bread obtained with these dough, were carried out and used to assess the impact of the degree of pre-fermentation on the stability of the dough and of the baked bread. Results showed that increasing the degree of pre-fermentation results in a reduction in the final dough and bread volume. Freezing applied to pre-fermented dough resulted in a baked bread with larger and less numerous gas cells. However, it was observed that applying a chilling step (4 °C for 120 min) before freezing the pre-fermented dough minimized the loss in bread volume (−40.5% vs. −27.5% in comparison to reference bread - direct baking).     

Effects of flour from different barley varieties on barley sour dough bread

Twenty flours from 16 different barley varieties cultivated in 1990 and 1992, and a Swedish reference flour, were fermented by Lactobacillus plantarum A1 to sour doughs. Barley breads (40% barley/60% wheat flour) from each flour type were baked with and without an admixture of barley sour dough in order to investigate how the sour dough admixture would affect the baking properties. A trained panel carried out sensory evaluation by conventional profiling on breads made from three of the barley varieties and the Swedish reference flour, made with and without sour dough admixture.

The barley varieties influenced both the sour dough properties and the properties of the barley bread. The pH of bread with sour dough ranged from 4.6 to 4.8 as compared to 5.4 to 5.6 in bread without sour dough. The acidity of the breads with sour dough ranged from 4.1 to 5.0 ml NaOH/ 10 g bread crumb as compared to 2.4 to 3.6 in breads without sour dough. In 14 of the twenty bread types an addition of sour dough lowered the bread volume. Breads with a sour dough admixture scored higher for total taste and acidulous taste than breads without sour dough. The β-glucan content of the flours had no significant influence on the sour dough or the sensory characteristics of the bread, except for the breadcrumb colour.     

Influences of lactic acid bacteria on technological, nutritional, and sensory properties of barley sour dough bread

Barley bread was baked with and without admixture of barley sour doughs, individually fermented with seven starter cultures containing lactic acid bacteria (including two with β-glucanase activity).

The aim of the study was to investigate how starter cultures influenced the baking-technological, nutritional and sensory properties of barley bread. Could degradation of β-glucans caused by sour dough admixture result in bread that was more easy to chew?

The starter culture influenced the volume yield, the total titratable acidity (S °) and the sensory properties. The amounts of lactate and acetate ranged from 0.20 to 0.26 and 0.03 to 0.08 g/100 g sour dough bread, respectively. The total titratable acidity in the sour dough breads varied between 4.1 and 5.4 ml 0.1 N NaOH/10 g bread. There were negative correlations between barley taste and total titratable acidity (S °). The acidulous taste of the sour dough breads seemed to mask the barley taste. The phytate of the barley sour dough breads was reduced below 0.5 μ mol/g, which does not inhibit mineral absorption, irrespective of starter culture. There was no significant difference in the total content of β-glucans between bread made with and without admixture of sour dough, irrespective of starter culture, rejecting the hypothesis that barley bread made with sour dough would be more easy to chew.     

Glucose oxidase effect on dough rheology and bread quality: A study from macroscopic to molecular level

Enzymes are used in baking to improve dough handling properties and the quality of baked products. Glucose oxidase (GO) is an enzyme with oxidizing effect due to the hydrogen peroxide released from its catalytic reaction. In this study, the macroscopic effect of increasing glucose oxidase concentrations on wheat dough rheology, fresh bread characteristics and its shelf life during storage was determined. A reinforcement or strengthening of wheat dough and an improvement of bread quality can be obtained with the addition of GO, although inverse effects were obtained when excessive enzyme levels were added. The analysis of the gluten proteins at molecular level by high performance capillary electrophoresis and at supramolecular level by cryo-scanning electron microscopy revealed that the GO treatment modified gluten proteins (gliadins and glutenins) through the formation of disulfide and non-disulfide crosslinks. The high molecular weight glutenin subunits showed to be the most susceptible glutenin fraction to the oxidation action of GO. Excessive addition of GO produced an excessive crosslinking in the gluten network, responsible of the negative effect on the breadmaking properties.     

Effect of heat-moisture treated maize starch on the properties of dough and bread

Twenty percent of wheat flour was substituted with heat-moisture treated maize starch (HMT-M) or native maize starch (N-M), and the dough properties and the bread qualities were studied. Bread was baked with optimum (farinogram water absorption (63.0–66.4%)), 70% and 75% of water at the presence or absence of shortening. Elasticity of the dough with HMT-M decreased as compared with that of N-M and the control (without any maize starches) as measured by farinograph. Differential scanning calorimetry (DSC) and viscograph results showed that HMT-M hardly swelled and gelatinized in the dough. Specific volume of bread and softness of crumb baked with optimum water absorption decreased by the substitution of HMT-M. Bread quality containing HMT-M was improved at 70% water absorption as compared with optimum water absorption. By the addition of shortening, the specific volume of bread baked with HMT-M increased and the grain structure became finer. However, the firmness of crumb baked with HMT-M at the presence or absence of shortening was the same. As a result, HMT-M is still needed to study further for its application in breadmaking.     

美国乳清制品和乳糖在烘焙食品中的应用

<正> 乳清蛋白是面包配方中重要的功能组分,能促进面包的褐变、改善面包的结构和风味,改善焙烤质量并能延缓面包老化。乳清配料的蛋白质、矿物质以及乳糖含量可以根据客户的要求调整,以满足不同的需求。这一点相当重要,因为乳清的组成和变性程度会影响乳清配料的功能性。以下几点可以作为选择乳清配料的应用指南:1.为了增加面包的体积,应选用乳糖含量低、蛋白质含量     

Frozen Dough and Partially Baked Bread: An Update

The bakery market is growing due to the development of new technologies related in freezing. In this contribution, the state of the art on frozen dough and bread is reviewed, giving special emphasis to the contributions of the last two decades. This article is especially focussed on being a useful guide of the research performed in the application of freezing at different steps of the breadmaking process, giving an overview of the direction in which the bakery market is moving. The raw material requirements, processing conditions and baked bread quality from frozen dough and partially baked bread are reviewed.     

Frozen Dough and Partially Baked Bread: An Update

The bakery market is growing due to the development of new technologies related in freezing. In this contribution, the state of the art on frozen dough and bread is reviewed, giving special emphasis to the contributions of the last two decades. This article is especially focussed on being a useful guide of the research performed in the application of freezing at different steps of the breadmaking process, giving an overview of the direction in which the bakery market is moving. The raw material requirements, processing conditions and baked bread quality from frozen dough and partially baked bread are reviewed.     

小麦胚芽在面包中应用的研究

本文初步探讨了小麦胚芽在二次发酵法制作面包中的应用,研究了不同小麦胚芽预处理条件、添加量和主面团加水量、面包改良剂使用量对面包体积比及面包质量评分的影响。结果表明:就面包体积而言,面包中添加麦胚片优于添加麦胚粉;烘烤、焙炒、脱脂处理的小麦胚芽均可应用于面包中,但添加烘烤麦胚的面包品质最佳,其次是脱脂麦胚,焙炒处理的麦胚面包质量较差,最佳小麦胚芽添加量、主面团加水量和面包改良剂使用量分别是6%、20%和0.6%。     

Impact of Green Tea Extract and Fungal Alpha-Amylase on Dough Proofing and Steaming

Green tea extract (GTE) was fortified into steamed bread as a functional ingredient to enhance its nutritional values. However, GTE might inhibit α-amylase activity and interact with gluten proteins, causing adverse effects on dough development and final loaf volume. This research investigated the effects of GTE and fungal alpha-amylase (FAA) on rheofermentometer characteristics, dough inflation parameters, and the specific volume of both dough and steamed bread. Rheofermentograph showed that the fortification of GTE did not affect the gassing power of yeast while it slightly inhibited the activity of FAA. Fortification of GTE at the level of 1.0 % decreased the dough inflation parameters and the specific volume of steamed bread. On the other hand, fortification of 60 ppm FAA enhanced the dough inflation parameters and increased the specific volume of steamed bread. Addition of 60 ppm FAA was able to fully compensate for the reduction of specific volume caused by the addition of 1.0 % GTE. Fortification of 0.50 % GTE produced steamed bread whose specific volume was not significantly different from that without GTE.     

Effects of trypsin‐hydrolyzed wheat gluten peptide on wheat flour dough

BACKGROUND: Gluten peptide was prepared by trypsin hydrolysis and characterized by high‐performance liquid chromatographic analysis. The effects on non‐frozen and frozen doughs of trypsin‐hydrolyzed gluten peptide (THGP) and its combination with ascorbic acid or KBrO₃ were investigated. RESULTS: Molecular analysis of THGP showed a decrease in the high‐molecular‐weight and an increase in the low‐molecular‐weight sodium dodecyl sulfate‐soluble fractions, compared with those of control wheat gluten. The addition of 8% THGP decreased the mixing time and tolerance of the dough, both with and without ascorbic acid or KBrO₃. However, the maximum resistance and extensibility of the rested dough containing 8% THGP, with and without ascorbic acid or KBrO₃, were not significantly different from those of the control dough. The addition of 8% THGP significantly increased the loaf volume of bread baked from non‐frozen dough when combined with 60 ppm ascorbic acid or 30 ppm KBrO₃, but it had a significant effect both with and without ascorbic acid or KBrO₃ on frozen‐dough bread. A large difference in volume was observed between breads made with and without THGP at the oven‐spring, rather than at proofing. CONCLUSION: The addition of 8% THGP increased the loaf volume of bread made from freeze‐damaged dough and this effect increased when THGP was combined with 60 ppm ascorbic acid. Copyright © 2008 Society of Chemical Industry     

Frozen Sangak dough and bread properties: Impact of pre-fermentation and freezing rate

The impact of pre-fermentation time and freezing rate on Sangak frozen dough and bread quality were studied. The pre-fermented doughs for 0, 30, 60, 90, or 120 min were frozen under –20, –25, or –30°C in air blast freezer. After 24 h storage at –18°C, dough samples were baked after final fermentation. The yeast viability, gassing power, and dough development for fresh and frozen Sangak doughs were determined. Crust color, density, and shear stress of bread obtained from fresh and frozen Sangak dough were evaluated. The results showed that yeast survival initially increased and then decreased with increasing freezing rate. The maximum yeast survival was observed at short pre-fermentation (30 min). A direct relationship was observed between gassing power, dough development, and yeast viability. From bread quality point-of-view, short pre-fermentation and higher freezing rate led to a more desirable bread.     

中性木聚糖酶在面包制作中的应用

通过探讨不同浓度的中性木聚糖酶对面粉粉质、面包焙烤品质以及面包贮存过程中老化程度的影响 ,研究中性木聚糖酶作为焙烤添加剂的可行性。结果表明 ,中性木聚糖酶能显著地改善面粉的粉质 ,当添加量为 0 3mL/kg(面粉 )时 ,面团的形成时间可减少 5 0 %左右 ;能有效地改善面包焙烤品质 ,明显地增加面包的体积和比容 ,同时可以改善面包心的弹性和硬度 ,减小面包皮的硬度 ;酶添加范围为 0 0 5～ 0 48mL/kg(面粉 ) ,能增加面包的抗老化作用 ,贮藏 7d后 ,面包的硬度和弹性没有明显变化 ,延长了货架期     

Dough-leavening by Zymomonas mobilis and Its Application to Breadmaking

Among five strains of Zymomonas mobilis strain Z6C had the highest leavening ability in doughs containing either glucose or sucrose. Z6C most efficiently leavened the dough when it contained 5% sucrose, and this leavening ability was twice as much as that of commercial compressed yeast. At the same concentrations of NaCl, the leavening ability of Z6C was reduced more than that of baker's yeast. When comparing baked goods made with yeast, those made with Z6C had similar specific volumes, but Z6C baked goods had slight acidic flavor. Chromatographic analysis of head-space gas of yeast-leavened bread showed that two chemicals appearing in Z6C leavened bread were missing.     

Effects of Waxy Wheat Flour and Water on Frozen Dough and Bread Properties

ABSTRACT:  The quality of bread made from frozen dough is diminished by changes that occur during freezing. New cultivars of waxy wheat flour (WWF), containing less than 2% amylose, offer unique properties for the production of baked products. In this study, dough properties and bread quality were investigated at various levels of WWF (0% to 45% flour weight) and water (55% to 65%). Dough stickiness increased with higher levels of WWF and water. During frozen storage, dough with greater WWF and lower water had less change in stickiness. Maximum resistance to extension (MRE) decreased with higher WWF and water. Dough with greater WWF and less water had less change in extensibility after frozen storage. Dough with greater WWF and water was more extensible. Nuclear magnetic resonance (NMR) studies showed that frozen dough with higher WWF content had lower transverse relaxation ( T ₂) time of 9 to 11ms. After frozen storage, dough with higher WWF still showed lower T ₂. Dough with 15% WWF had higher yeast activity. Bread made from 15% and 30% WWF had higher volume in bread made from unfrozen and frozen dough. Bread firmness decreased with higher amounts of WWF and water. This research demonstrated that specific combinations of WWF and water produced a better quality of frozen dough and bread.     

How Do Xanthan and Hydroxypropyl Methylcellulose Individually Affect the Physicochemical Properties in a Model Gluten‐Free Dough?

To better understand the physicochemical changes imparted by hydrocolloids on gluten-free dough, 2 hydroxypropyl methylcelluloses (HPMCs) and xanthan gum were added at 2%, 3%, and 5% to rice cassava dough without the addition of alternative proteins. The formulated doughs were analyzed using thermoanalytic and rheological techniques to determine the role of water and subsequent flow behavior upon hydrocolloid addition. The baked loaves were then measured for specific loaf volume and tensile strength to determine bread quality. Thermogravimetric analysis (TGA) results revealed that hydrocolloid-added dough held water more tightly than the rice cassava control with an additional water distribution at 85 to 88 °C. Rheologically, the increase of elastic moduli in the low methoxy HPMC and xanthan-added dough became more pronounced with gum addition; however, both HPMC formulations had increased viscous moduli allowing the gas cells to expand without collapsing. In the bread, the final specific loaf volume increased with high methoxy HPMC (2% to 5%) and low methoxy HPMC (2%) but was depressed with increased addition of low methoxy HPMC (5%) and xanthan (3% and 5%). Crumb hardness was decreased in high methoxy HPMC loaves but was increased significantly in low methoxy HPMC (5%) and xanthan (5%) formulations. From the gums studied, it was concluded that high methoxy HPMC was the optimum hydrocolloid in the rice cassava gluten-free dough. PRACTICAL APPLICATION: Two types of hydrocolloids, xanthan gum and HPMC, were individually added to a gluten-free rice cassava formulation. Based on the thermoanalytic and rheological studies on dough, as well as the bread quality studies, high methoxy HPMC at 5% addition was determined to optimally improve the bread quality when only gum addition was considered. This study indicates the potential use of high methoxy HPMC as an additive in gluten-free bread formulations prior to considering alternative proteins.     

Influence of yeast and vegetable shortening on physical and textural parameters of frozen part baked French bread

The objective of this project was to study the influence of yeast and vegetable shortening on physical and textural parameters of frozen part baked French bread stored for 28 days and to produce a frozen part baked bread with physical and textural characteristics similar to those of the fresh one. Four formulations were used with different quantities of yeast and vegetable shortening. Dough was prepared by mixing all ingredients in a dough mixer at two speeds. After resting, the dough was divided into 60 g pieces, molded and proofed. The bread was partially baked for 7 min at 250°C, in a turbo oven. After cooling, it was frozen until the core temperature reached −18°C and stored at the same temperature up to 28 days. Once a week, samples were removed from the freezer to complete the baking process, without previous thawing. Mass, volume, water content, firmness, cohesiveness and springiness were measured 1 h after final baking. Resistance to extension and extensibility of dough were measured after mixing. Specific volume and chewiness were determined. Bread with higher yeast content presented a higher specific volume, whereas vegetable shortening reduced its crumb firmness and chewiness.     

Mixing properties of fibre-enriched wheat bread doughs: A response surface methodology study

Fibre-enriched baked goods have increasingly become a convenient carrier for dietary fibre. However, the detrimental effect of fibres on dough rheology and bread quality continuously encourages food technologists to look for new fibres. The effect of several fibres (Fibruline, Fibrex, Exafine and Swelite) from different sources (chicory roots, sugar beet and pea) on dough mixing properties when added singly or in combination has been investigated by applying a response surface methodology to a Draper-Lin small composite design of fibre-enriched wheat dough samples. Major effects were induced on water absorption by Fibrex that led to a significant increase of this parameter, accompanied by a softening effect on the dough, more noticeable when an excess of mixing was applied. Conversely, Exafine increased water absorption without affecting the consistency and stability of dough, which even improved when combined with Swelite. Fibruline showed little effect on dough mixing parameters, but showed synergistic effects with pea fibres. The overall result indicates that the use of an optimised combination of fibres in the formulation of fibre-enriched dough allow improving dough functionality during processing.