首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 46 毫秒
1.
The increasing interest in functional and healthy food products has promoted the use of germinated soybean flour in the manufacture of foods for human consumption. Considering the beneficial effects of soy and its germination, farinograph and extensograph were used to study the effect of adding defatted flour of germinated (32 °C, 72 h) or non-germinated soybean—at different dry protein ratios (0, 0.5, 1.0, 1.5%)—to wheat flour on: water absorption (WA), maximum consistency time (MCT), dough stability (S), maximum resistance to extension (R max), and dough extensibility (L). Baking tests (straight-dough procedure) were also performed to evaluate the effect of this addition on bread characteristics: loaf volume, texture (firmness, compression force, resilience), color (L*, a*, b*), crumb–grain structure (cell density, mean cell area, shape factor), and consumer acceptance (sensory analysis). Addition of both kinds of soybean flours increased the values of farinographic parameters (WA, MCT, S), although they did not have significant effects (p > 0.05) on extensographic properties (R max, L). Loaf volume and crumb color were improved as soy flour addition was increased, whereas crust color was not affected (p > 0.05). Texture analysis showed that the addition of soy flour produced breads similar or better than the control, whereas the addition of GSF produced a coarser crumb grain. No detectable differences were found among samples during the sensorial analysis. Germinated soybean flour was better to improve dough breadmaking properties.  相似文献   

2.
Resistant starch can be used to reduce the availability of carbohydrates in baked products. In this study, the effect of type 4 resistant wheat starch (RS4) on wheat flour dough and breads was evaluated. Wheat flour was substituted by RS4 at 10%, 20% and 30% w/w (RS10, RS20 and RS30, respectively). Rheological and thermal behaviours of dough were evaluated. Besides, bread quality, starch digestibility and bread staling were analysed. All substituted dough exhibited viscoelastic behaviour but lower elastic and viscous moduli. Regarding to bread quality, specific volume and crumb texture were negatively affected in samples with RS4. However, all samples were technologically acceptable. During storage, crumb hardening was observed in breads without and with RS4 but amylopectin retrogradation was not particularly affected. The in vitro digestibility of bread with RS showed a lower release of reducing sugars and a lower estimated glycaemic index, suggesting a healthier profile for these breads.  相似文献   

3.
BACKGROUND: The effects of different phenolic acids on the rheological properties and gluten proteins of hard wheat flour dough and bread were investigated. Caffeic, ferulic, syringic and gallic acids were each blended with hard wheat flour at a concentration of 4.44 µmol L?1 g?1 flour. RESULTS: Mixing time and tolerance were reduced with the addition of phenolic acids. The phenolic acids reduced the maximum resistance to extension (Rmax) and increased the extensibility of dough, with effects in the following order: gallic < syringic < ferulic < caffeic acid. The effect on Rmax was more pronounced in overmixed dough. Loaf volume was most significantly decreased with the addition of caffeic acid. Extraction of sodium dodecyl sulfate‐soluble high‐molecular‐weight proteins was increased in both mixed and fermented doughs by the addition of ferulic and caffeic acids. The order of influence of the phenolic acids on the rheological properties and protein structure of dough and bread was consistent with that of their antioxidant activity. CONCLUSION: The addition of caffeic and ferulic acids reduced Rmax and increased the extensibility of hard wheat flour dough by modifying the high‐molecular‐weight gluten, which resulted in decreased bread volume. Copyright © 2011 Society of Chemical Industry  相似文献   

4.
This investigation is aimed at developing a new cereal-based product, with increased nutritional quality, by using Bifidobacterium pseudocatenulatum ATCC 27919 as starter in whole wheat sourdough fermentation and evaluating its performance. Four different sourdough levels (5%, 10%, 15%, and 20% on flour basis) in bread dough formulation were analysed. The effects of the use of bifidobacteria in sourdough bread were comparatively evaluated with controls (yeast and/or chemically acidified sourdough with antibiotics). The sourdough and dough fermentative parameters analysed were pH, total titratable acidity, d/l-lactic and acetic acids. Bread performance was evaluated by specific volume, slice shape, crumb structure and firmness, crust and crumb colour, pH, total titratable acidity, and d/l-lactic and acetic acids, phytate, and lower myo-inositol phosphate contents. The sourdough breads showed similar technological quality to the control sample, with the exception of specific bread volume (decreased from 2.46 to 2.22 mL/g) and crumb firmness (increased from 2.61 to 3.18 N). Sourdough inoculated with bifidobacteria significantly increased the levels of organic acids in fermented dough and bread. The Bifidobacterium strain contributed to the fermentation process, increasing phytate hydrolysis during fermentation owing to the activation of endogenous cereal phytase and its own phytase, resulting in bread with significantly lower phytate levels (from 7.62 to 1.45 μmol/g of bread in dry matter). The inclusion of sourdough inoculated with bifidobacteria made possible the formulation of whole wheat bread with positive changes in starch thermal properties and a delay and decrease in amylopectin retrogradation.  相似文献   

5.
Abstract

The effect of dough mixing time and temperature on the extensographic characteristics of yeast sweet dough was studied. Changes on bread structural characteristics were also evaluated. Mixing time was varied from 15 to 35 min. Temperature was worked out on four ranges: 16–19, 19–22, 22–25, and 25–29°C. Results showed that extensibility did not change at short mixing times (15 min). As temperature and mixing time increased, extensibility also increased, varying from 9.6 to 29 cm. Resistance to extension was a function of both temperature and mixing time, reaching a maximum value of 650 extensographic units (EU) and a minimum of 180 EU. As temperature increased, greater resistance to the extension values were observed at shorter mixing times. Bread apparent density was also affected by mixing time, whereas temperature did not affect. Firmness also increased with mixing time and temperature. Extensographic and bread characteristics showed an abrupt change depending on process conditions, indicating a limit of energy input to provoke this behavior. Although rheological results could be fitted to a mathematical model, there was not a single equation that fits all data.  相似文献   

6.
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  相似文献   

7.
This study investigates the exploitation of buckwheat sourdough for the production of wheat bread. The fermentation induced extensive hydrolysis of buckwheat main storage proteins, but did not influence the total protein, starch and polyphenols content of buckwheat. Buckwheat sourdough was incorporated at 10 and 20?% (w/w) in wheat dough, and control doughs were produced with the addition of a chemically acidified (CA) buckwheat batter. The addition of buckwheat sourdough greatly affected the rheological properties of the dough, by inducing a strengthening of the gluten network and decrease in elasticity. The acidification of wheat dough also stimulated the baker’s yeast activity during proofing, resulting in higher release of CO2 in shorter times (volume of CO2 released (ml), control dough, 1,671.5; dough with 10?% sourdough, 2,600; dough with 10?% chemically acidified dough, 2,715.5). The properties of wheat bread were enhanced by the addition of 10?% buckwheat sourdough, which led to higher specific volume (control, 3.41?ml/g; bread with 10?% sourdough, 4.03?ml/g) and softer crumb (crumb hardness, control, 5.28?N; bread with 10?% sourdough, 3.93?N). On the other hand, the higher acidification level did not influence the bread volume, but slightly hardened the crumb (crumb hardness, bread with 20?% sourdough, 7.41?N; bread with 20?% chemically acidified dough, 6.48?N). The fermentation positively influenced the nutritional properties of buckwheat flour and wheat bread, in terms of polyphenols (control bread, 8.84?mg GAE/100?g; bread with 10 and 20?% sourdough, 17.83 and 18.20?mg GAE/100?g, respectively) and phytic acid contents. Incorporation of buckwheat sourdough also led to an extension in the shelf life of wheat bread, which became more evident for the higher addition level. Overall, the results of this study suggest that buckwheat sourdough represents a suitable tool for enhancing the overall quality and nutritional properties of wheat bread.  相似文献   

8.
A maltotetraose‐producing enzyme (G4‐amylase) was utilized to improve the baking performance of whole‐grain wheat flour. Whole‐grain bread dough prepared with G4‐amylase showed reduced water absorption and increased development time, while the dough stability was not affected. Also, the G4‐amylase‐treated samples exhibited lower Mixolab torque values than the control upon heating and cooling. Rheological measurements showed the decreased ratio of Rmax/E and increased tan δ, clearly demonstrating that the viscous characteristics of whole‐grain bread dough became dominant with increasing levels of G4‐amylase. The use of G4‐amylase produced whole‐grain wheat breads with a variety of maltooligosaccharides, primarily maltotetraose that positively contributed to the bread volume (1.2‐fold higher than the control). Moreover, G4‐amylase delayed the crumb firming of whole‐grain wheat bread during a 7‐d storage period, showing that it can function as an antiretrogradation agent to enhance the quality attributes of whole‐grain wheat bread.  相似文献   

9.
Two kinds of endoxylanase (XYL), one is a solid-phase enzyme (S-XYL) and the other a liquid-phase enzyme (L-XYL), were used to test their effect on the properties of dough and the quality of Chinese steamed bread (CSB). The textural properties of wheat dough made with the two enzymes were investigated. Parameters from the texture profile analysis (TPA) were determined after mixing the dough at 0th, 5th, 10th, 15th and 20th min, respectively. Both enzymes decreased farinograph parameters. They also influenced mixograms including decreasing time to peak and peak height. It was apparent that the decrease in hardness of the dough by adding S-XYL and L-XYL, respectively was more than that of the control sample and the sample with added yeast. It was found that the longer the time of fermentation, the lower the hardness of the dough. The mixing time was reduced by adding L-XYL by about 27.5%. The fermentation time was decreased by adding S-XYL or L-XYL. The addition of S-XYL and L-XYL on CSB resulted in increased specific volume, spread ratio and decreased crumb softness. A decreasing trend in L* value, a slightly increasing tendency in a* value and a slightly decreasing trend in b* value exist in crumb colour.  相似文献   

10.
The study was carried out to investigate the effect of additives (lactic acid, fat and sodium chloride) and process variables (mixing duration and fermentation temperature) on dough development and gaseous release characteristics measured by Rheofermentometer F2 and bread volume. Hm (maximum dough height) was most significantly affected by mixing duration and sodium chloride whereas Hm′ was most significantly affected by fermentation temperature and fat levels. Increased levels of fat (%) showed improving effects on dough development and bread volume, however fat addition did not counteract the adverse affects of over mixing and addition of lactic acid and sodium chloride at higher levels. The models computed had R2 value ranged between 91.5–98.7%, indicating they are appropriate and can be a useful tool to predict the effect of addition of lactic acid. fat and sodium chloride and process variables mixing duration and fermentation temperature on dough development, gaseous release and bread volume.  相似文献   

11.
The performance of Lactobacillus sanfranciscensis TMW 1.392 and its levansucrase deletion mutant TMW 1.392 Δlev in wheat dough was compared. The effects of both strains on dough and bread characteristics were determined in order to find benchmarks for in situ production of exopolysaccharides (EPS). Growth and acidification were lower in doughs prepared with the Δlev mutant than in those employing the wild type. Extensogram resistance of the dough was reduced and extensibility increased with the addition of L. sanfranciscensis levan. Added EPS positively influenced water absorption, bread volume and firming of the crumb. In situ production of EPS was not sufficient to achieve the same positive effects of EPS, as they partially overlapped with effects resulting from enhanced acidification. Control doughs were made to separate effects of predough, EPS and different metabolism/acidification. High acetic acid levels decreased extensibility and volume. High lactic acid levels negatively influenced crumb hardness and firming kinetics. The use of knock out mutants proved helpful to judge overall performance of a strain, although the interpretation of specific effects must consider all changes in its metabolism.  相似文献   

12.
The influence of chemical and biological acidification on dough rheological properties and bread quality has been investigated. Two different flour types were used. Dough was chemically acidified with lactic acid. Two types of biologically acidified dough were prepared: dough with dry sourdough and with a Lactobacillus brevis preferment. Wheat dough rheological properties were investigated using the Farinograph, Extensograph and Amylograph. The baking response was also determined using standard baking tests. Addition of acidifiers resulted in firmer doughs with less stability, decreased extensibility and decreased gelatinisation maximum. The biological acidifiers increased the bread specific volume. Lactic acid addition had no influence on bread specific volume. In general, biological and chemical acidification decreased bread hardness. The addition of dry sourdough significantly decreased the lightness and increased the yellowness and redness of the bread crumb. The crust chroma, hue angle and brownness index were significantly changed by addition of acidifiers.  相似文献   

13.
High levels of soy flour added to wheat bread produce negative effects on gluten network formation, dough properties, and on bread final quality. The objective of this study was to assess the influence of three enzymes, transglutaminase (TG), glucose oxidase (GOX), and endoxylanase (XYL), on dough properties and final quality of high-protein breads. The addition of TG and GOX increased the mixing stability and maximum resistance of dough, decreased its extensibility, and produced stronger and more consistent dough samples. XYL incorporation produced opposite results. XYL addition and the lowest GOX dose increased bread volume significantly and decreased initial crumb firmness, while high doses of TG (0.3%) produced detrimental effects on bread volume and crumb firmness. In conclusion, XYL and GOX 0.001% addition improved the final quality of soy-fortified breads, but XYL was the best additive to improve dough properties, bread volume, and quality.  相似文献   

14.
Maize is used for bakery and for gluten‐free food for coeliac patients. Our objective was assessing diversity for dough rheology and breadmaking in maize with different origins, grain types and growth cycles. Endosperm type affected bread crumb colour having dent maize higher L* and a* and instant recovery speed. Population origin affected flotation index, onset pasting temperature, bread crumb colour, hardness and instant recovery speed. Finally, growth cycle affected flotation index, crumb colour L* and a* and cohesiveness. Water‐binding capacity, crumb colour and hardness were the most discriminative parameters for maize. The maize population Andaluz/Daxa was the less distant from wheat parameters, and Tremesino was the most different.  相似文献   

15.
Partially baked frozen (PBF) process prolongs bread shelf life, but diminishes its volume and crumb texture. Therefore, we investigated the possibility of using sourdough for the quality improvement in PBF wholewheat bread. Sourdough was fermented with either Lactobacillus plantarum, Lb. brevis or Leuconostoc mesenteroides mixed with yeast Candida humilis and added at 7.5, 15, 22.5 or 30% on bread dough basis. The choice of sourdough starter significantly affected bread acidity characteristics, flavour, specific volume, shape and crumb firmness. The sourdough amount and acetic acid content of bread inversely correlated to flavour score, specific volume, shape and crumb softness. The overall quality of PBF wholewheat bread was most efficiently improved after adding Lb. plantarum sourdough at 15–22.5%, resulting in retarded firming rate (74–94%) and improved specific volume (25–28%) in comparison with PBF bread without sourdough. Such sourdough has lactic to acetic acid higher than previously recommended for traditional sourbreads.  相似文献   

16.
Three trials were carried out to determine the effect of wet gluten, acetic acid, fat, sodium chloride and mixing duration on dough development, gas release and bread characteristics using regression analysis. Maximum dough height was significantly affected by acetic acid, wet gluten, mixing duration and sodium chloride whereas maximum gas formation was significantly affected by acetic acid and sodium chloride levels. The addition of fat had significant effects on bread volume. Sodium chloride affected overall acceptability followed by wet gluten, mixing duration and fat levels. Bread volume and overall acceptability decreased with an increase in mixing duration. Increased levels of sodium chloride increased bread volume and overall acceptability and decreased CO2 production. Addition of fat at a level of more than 3% caused a decrease in acceptability. Bread volume and acceptability progressively increased with the increase in wet gluten levels.  相似文献   

17.
The use of composite flour for bread making is gradually gaining prominence worldwide due to some economic and nutritional reasons. However, studies on the application of functional ingredients purposely to improve composite bread quality are very few. This paper examines the functional role of xanthan gum (XG) on the properties of dough and bread from composite cassava-wheat flour. The viscoelastic properties of dough and gas retention characteristics of batter as well as the fresh and storage properties of bread from the composite flour (90% wheat plus 10% cassava) were studied. The crumb cell structure was also studied using digital image analysis technique. Inclusion of XG had significant effects on the dough tenacity and extensibility and sensory acceptability of fresh composite bread. The oven spring, specific volumes of bread loaf and crumb softness were higher at 1% XG content. Also, addition of XG made the composite bread samples had more open crumb structure and better sensory acceptability. However, moisture loss and crumb firming during bread storage were best reduced when 1% XG was added to bread formulation.  相似文献   

18.
Heating Conditions and Bread-Making Potential of Substandard Flour   总被引:1,自引:0,他引:1  
ABSTRACT Heating weak bread flours (commercial cookie flour; commercial stone‐milled bread flour; Fundulea, a weak bread cultivar) at 80°C for 15 min had a positive effect on bread volume (P < 0.05). This positive effect was best seen when ascorbic acid was removed from bread formulation. Crumb springiness and fineness of grain, but not crumb hardness, were significantly improved after flour heating; cohesiveness improved with heated cookie flour (P < 0.05). After heating, flour a‐amylase content was lower; dough‐mixing stability of cookie flour doubled to 7.1 min but dropped from 18.0 to 4.8 min with standard bread flour. Heating offers possibility to upgrade substandard flour for bread‐making applications, especially in oxidant‐free dough system.  相似文献   

19.
L. Flander  T. Suortti  K. Katina  K. Poutanen 《LWT》2011,44(3):656-664
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.  相似文献   

20.
This study was to evaluate the influence of hemp addition and extrusion conditions on properties of dough and bread. The extruded and non-extruded hemp/ rice flours with different hemp/rice ratio were mixed with wheat flour at 15% ratio. In those flour assays, extrusion greatly decreased the paste viscosities, while the addition of hemp inhibited the decrease of peak viscosity on the extrusion condition. The onset gelatinization temperature was extended due to the hemp addition. The test on dough properties showed that extrusion increased water absorption, arrival time, weakness, extensibility, and the volume after 105 min fermentation, and decreased the stability time and elasticity of dough, while hemp addition mainly increased the weakness and extensibility. For bread properties, extrusion decreased the specific volume, crust and crumb L value, and uniformed air cells, when the hemp addition increased the bread specific volume and decreased the hardness during storage time.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号