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1.
Texture properties of wheat doughs were determined with a texturometer by using texture profile analysis (TPA) as well as Chen and Hoseney methodologies. The time elapsed between two compressions and strain were optimized so that meaningful values were obtained for TPA. Single effects and interactions between flour type, the breadmaking process and anti-staling additives (i.?e. monoglycerides, diacetyl tartaric ester of monoglycerides, sodium stearoyl lactylate, carboxymethylcellulose and hydroxypropylmethylcellulose) on dough texture properties (i.?e. springiness, resilience, hardness, cohesiveness, adhesiveness, chewiness, gumminess and stickiness) were estimated. The breadmaking process and addition of hydrocolloids had the most important effects and interactions on TPA. Hydrocolloids and α-amylase increased dough stickiness. Dough cohesiveness was a good predictive parameter of bread quality. Water content, acidity values and gluten quality were the main factors determining the texture properties of dough.  相似文献   

2.
The aim of the study was to check if maltodextrins of various dextrose equivalents (DE) could be used to improve stability and quality of gluten-free bakery products, and effectively reduce starch retrogradation. The maltodextrins, which were used for partial replacement of starch in the recipe for gluten-free dough, were characterised by DE 3.6, 15.3, 18.0 and 21.8. Basing on the obtained results it was concluded, that the addition of applied maltodextrins significantly influences starch gelatinisation, by increasing pasting temperature and reducing viscosity of the obtained pastes. Rheological properties of the obtained dough are also modified by maltodextrins, which weaken its structure and increase deformation sensitivity. The addition of maltodextrins with low DE (3.6) diminishes loaf volume and causes deterioration of bread quality. Maltodextrins with higher DE, especially 18.0 and 21.8, positively influence bread volume and have a beneficial influence on crumb hardening during storage. Maltodextrin with the highest DE is also an effective factor reducing recrystallisation enthalpy of amylopectin.  相似文献   

3.
 In this research, the effects of lactic acid bacteria starter and hop additives, similar to yeast, on the quality of the resulting dough and bread, especially the development of staling, were investigated. In the experiments, a mixed culture containing Lactobacillus plantarum and L. fermentum was inoculated at the levels of 2% and 4% depending on the flour quantity. Hop additives were used at the levels of 0.025% and 0.05%. The effects of type-1, type-3 and type-5 flours were investigated with respect to their chemical composition, physical properties and bread experiment at three different periods, i. e. December 1993, March and June 1994. According to the results obtained, the best values for all three types of flours were found to occur in the second period, i. e. March 1994, whereas the lowest values were observed at the end of the third term. Almost all additives had an effect on dough and bread properties, pH and acidity development and, moreover, on the development of staling. The combined application of 0.05% hop and lactic acid bacteria starters at the levels of 2% and 4% was the most effective at delaying staling. Received: 10 December 1996  相似文献   

4.
Slaughter blood haem was encapsulated in lecithin : cholesterol Liposomes. Wheat flour was fortified with this mixture at two levels (60 and 100 mg/100 g flour) using the haem liposomes as iron source. The effect of haem fortification on gluten and fat content of flours was determined, as were the effects of fortification on dough visco‐elastic characteristics (water absorption, development time, dough stability and breakdown time). The baking properties of the breads were also investigated. The addition of haem liposomes increased the fat content of flours, and had a positive effect on the stability and rheological characteristics of the dough. Loaf volume and crumb uniformity was improved. These results indicate a potential nutritional use for haem liposomes..  相似文献   

5.
 In this research, the effects of lactic acid bacteria starter and hop additives, similar to yeast, on the quality of the resulting dough and bread, especially the development of staling, were investigated. In the experiments, a mixed culture containing Lactobacillus plantarum and L. fermentum was inoculated at the levels of 2% and 4% depending on the flour quantity. Hop additives were used at the levels of 0.025% and 0.05%. The effects of type-1, type-3 and type-5 flours were investigated with respect to their chemical composition, physical properties and bread experiment at three different periods, i. e. December 1993, March and June 1994. According to the results obtained, the best values for all three types of flours were found to occur in the second period, i. e. March 1994, whereas the lowest values were observed at the end of the third term. Almost all additives had an effect on dough and bread properties, pH and acidity development and, moreover, on the development of staling. The combined application of 0.05% hop and lactic acid bacteria starters at the levels of 2% and 4% was the most effective at delaying staling. Received: 10 December 1996  相似文献   

6.
ABSTRACT:  The objective of this study was to determine the effects of hydrocolloids in dough (xanthan 0.02%, 0.06%, and 0.1%; κ-carrageenan and carboxymethylcellulose 0.2%, 0.6%, and 1.0%) and duration of frozen storage on the quality of finished bakery product. Doughs were prepared with different concentrations of gums, stored at −18 °C and analyzed after 0, 7, 14, and 30 d for fermentation activity of yeast and rising time of dough. At the end of each frozen storage interval, bread was prepared and characterized for specific volume, crumb firmness, and crumb structure. The addition of the gums had significant effects on dough performance and quality of the final product. Gums at all tested concentrations reduced fermentation activity of yeast and prolonged the rising time of dough, which was similar to the effects of frozen storage. However, specific volume of bread for the control sample significantly decreased on the 30th d of frozen storage. Addition of hydrocolloids resulted in higher specific volume of loaves compared to the specific volume of control sample loaves. With the increase of the duration of frozen storage the specific volume of bread decreases in all analyzed samples. This decrease is less in the samples with hydrocolloids compared to the decrease in the control sample. The addition of 0.1% xanthan accomplished the same or higher values for specific fermentation activity, specific volume, and penetrometric's number compared to the values accomplished by the addition of 1% carboxymethylcellulose and κ-carrageenan, respectively.  相似文献   

7.
Inulin preparations with different degree of polymerization (HSI with a DP < 10, GR − DP ? 10 and HPX − DP > 23) were used for the production of gluten-free bread. It was found that an addition of investigated compounds resulted in an increase of loaf volume and reduction of crumb hardness. However, internal structure of the obtained loaves was less uniform and more open than in control bread. Generally, inulin preparations with lower degree of polymerization had stronger effect on all analyzed parameters than that with higher DP. A decrease in staling was observed (measured as the rate of crumb hardening), which was caused by the presence of inulin. The highest content of retrograded amylopectin was found for crumb with HSI, and the lowest for samples with HPX.  相似文献   

8.
 Dairy ingredients are used in breadmaking for their nutritional benefits and functional properties. The effects of the traditionally-used whole and skimmed milk powder, sodium caseinate, casein hydrolysate and three whey protein concentrates on dough rheology and bread quality were studied. Whole and skimmed milk powders improved sensory characteristics. Sodium caseinate and hydrolysed casein displayed beneficial functional properties in breadmaking including low proof time, high volume and low firmness. Both ingredients increased dough height measured with the rheofermentometer. Bread with 2% or 4% sodium caseinate added was rated highly in sensory evaluation. Incorporation of whey protein concentrates generally increased proof time, decreased loaf volume and decreased dough height measured with the rheofermentometer. Received: 6 April 1999 / Revised version: 13 July 1999  相似文献   

9.
The objective of the study was to investigate the impact of germinated brown rice flour (GBRF) on the mechanism of high gluten wheat flour (HGWF) network formation and dough properties. Therefore, dough properties, microstructures, stability mechanism and bread quality were evaluated. Results showed that HGWF+10%GBRF exhibited a higher dough stability time (DST), pasting temperature, storage modulus (G′) and loss modulus (G′′), as well as a lower compliance value. The microstructure of dough showed that GBRF interfered with the self-organization of gluten protein molecules and affected the formation of gluten network structure. The disulfide bonds and β-sheet structure were proved to play an important role in facilitating the formation of a stable three-dimensional network structure, which revealed the regulatory mechanism of GBRF in maintaining the dough stability and strength. Furthermore, the dough mixing properties and texture parameters (i.e., hardness and fracturability) of breads were significantly correlated. Overall, GBRF can be used as a potential ingredient for whole grain products and its realistic role in bread-making has been demonstrated.  相似文献   

10.
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.  相似文献   

11.
12.
 The textural properties of wheat doughs made with different commercial amylases, xylanases/pentosanases, lipases and glucose-oxidase, singly and in mixed combinations, were investigated. Parameters from the texture profile analysis (TPA) and measurement of stickiness (Chen and Hoseney test) were determined after mixing the dough and after it had rested for 3.5 h. Resting of doughs led to softer and less cohesive doughs, with higher adhesive properties. Enzymes acted quickly and induced significant changes in the textural properties of doughs immediately after mixing. The influence of enzymes continued during resting. Xylanases/pentosanases substantially reduced dough consistency and increased stickiness, while addition of glucose-oxidase and specific lipases overcame these effects. Strong correlations could be established between different TPA parameters and stickiness and bread quality characteristics (i.e. volume, density and texture). Bread quality could be described by a single or multiple linear combination of textural variables. Received: 21 May 1997 / Revised version: 10 July 1997  相似文献   

13.
Emulsifiers are widely used in bakeries as dough strengtheners and crumb softeners, but there is a great diversity of compounds with emulsifier action. The objective of this study was to analyze the influence of emulsifiers with different functionalities on the rheological characteristics of wheat dough, as well as their effect in the final bread parameters, including behavior during aging. All the emulsifiers tested increased dough stability, although the extent of this effect was concentration-dependent. The presence of emulsifier retarded dough proofing; in consequence, longer proofing times would be required when emulsifiers are used. In fact, the positive effects of emulsifiers on bread volume were only observed with long proofing times, and that also became evident when crumb hardness was analyzed. Sodium stearoyl lactylate, sucrose ester, lecithin and enriched lecithin were the emulsifiers with the greatst crumb softening effects at extended proofing times. However, when the objective is a hardening delay during storage, the emulsifiers of choice are monoglyceride and lecithin enriched in lysophospholipids. This study reveals the importance of the proofing period to the functionality of the emulsifiers when used for breadmaking performance.  相似文献   

14.
The staling of bread has previously been studied by differential scanning calorimetry and by simple rheological measurements. In this collaborative study, two spectroscopic techniques (Fourier transform mid infrared spectroscopy and near infrared reflectance spectroscopy) have been used in addition to differential scanning calorimetry to follow the progress of bread staling. Using each technique, changes in measured properties were apparent which, when fitted by first order exponential equations, gave calculated rate constants of similar magnitude. It is postulated that each technique gives independent information about the crystallisation process in the amylopectin fraction of the bread crumb.  相似文献   

15.
为了提高低血糖生成指数(Glycemic Index,GI)杂粮复合烤制馒头的品质,以青稞粉、藜麦粉和荞麦粉为主要原料,采用单因素和正交实验对杂粮复合烤制馒头的配方和工艺进行了优化.结果表明,杂粮复合烤制馒头的最优配方及工艺条件为:青稞粉添加量5%,藜麦粉添加量5%,荞麦粉添加量20%;改良剂加量0.6%,酵母添加量1...  相似文献   

16.
Composite wheat–cassava and wheat–maize flours were produced in ratio 100:0. 60:40, 50:50, 40:60 and 0:100 respectively. Thermo‐physical properties of bread dough were determined. For wheat –cassava composite bread dough, moisture content ranged between 44.02 ± 2.04 to 51.31 ± 2.99% dry basis (db), density (1035.2 ± 20.4 to 975.6 ± 12.6 kg m?3), specific heat capacity (2.51 ± 0.61 to 3.01 ± 0.42 kJ kg?1 K) and thermal conductivity (0.362 ± 0.13 to 0.473 ± 0.12 W mK?1). While wheat–maize mixture gave 44.14 ± 1.94 to 45.09 ± 1.26%(db) of moisture content, 981.4 ± 16.3–960.4 ± 22.5 kg m?3 density, 1.77 ± 0.17–2.61 ± 0.63 kJ kg?1 K specific heat capacity and 0.36 ± 0.07–0.39 ± 0.02 W mK?1 thermal conductivity. Effects of substitutions was significant on moisture content and thermal conductivity of dough while non significant influence was recorded on density and specific heat capacity at P < 0.05.  相似文献   

17.
Summary Changes in mono- and disaccharides and acetic and lactic acid production of six different straight doughs elaborated with combinations of pure strains of yeastsSaccharomyces cerevisiae andCandida boidinii and lactic acid bacteriaLactobacillus plantarum andStreptococcus sp have been investigated, as well as the baking quality of the resulting breads. The type and proportion of the fermentative microorganisms were found to influence the biochemical activity of the doughs. The sugar levels after mixing reached different proportions, depending on the type of sugar and the type of microorganisms used. After proofing, the glucose and fructose content of the doughs decreased to 0.01%–0.02% db and maltose decreased to 0.45%–0.11 % db. Acetic and lactic acids underwent variable changes during fermentation, depending on the type of dough. Lactic acid showed higher levels than acetic acid. Bread made from these doughs had different sensory characteristics, texture, edibility and overall acceptance, as well as different lactic and acetic acid contents, depending on the mixture of microorganisms inoculated.
Biochemische Merkmale und Leistungsfahigkeit der mit Mischungen reiner Mikroorganismen hergestellten Weizenbackteige
Zusammenfassung Die Forschungsaufgabe befaßte sich mit den Veranderungen der Mono- und Disaccharide, mit der Entstehung von Essig- und Milchsaure in sechs Teigen, die mit Kombinationen reiner HefekulturenSaccharomyces cerevisiae undCandida boidinii und MilchsäurebakterienLactobacillus plantarum undStreptococcus sp hergestellt waren und mit den sich daraus ergebenden Qualitätsmerkmalen der Brote. Die Art und Anteile der Mikroorganismen übten einen entscheidenden Einfluß auf die biochemische Aktivität der Teige aus. Nach dem Knetvorgang konnten unterschiedliche Gehalte gemäß der eingesetzten Saccharide und Mikroorganismen festgestellt werden. Der Glucose- und Fructoseanteil der fermentierten Teige verringerte sich auf 0,01–0,02% t. g., der Maltoseanteil auf 0,45-0,11% t.g. In den einzelnen Teigen veranderten sich wahrend der Garung die Essig-und Milchsauregehalte unterschiedlich. Bei der Milchsaure konnte eine grbBere Zunahme und somit höhere Endgehalte als bei der Essigsaure festgestellt werden. Die mit diesen Teigen hergestellten Brote erreichten verschiedene Textureigenschaften (Weichheit der Krume) und sensorische Merkmale, insbesondere Kaufahigkeit und Geschmack Bowie einen, entsprechend der Mikroorganismenmischung, höheren oder geringeren Milch- und Essigsäuregehalt.


Presented at the 8th International Cereal and Bread Congress, Lausanne, Switzerland, June 1988.

This paper is a part of a doctoral thesis  相似文献   

18.
The objective of this work was to study the effects of the combination of glucose oxidase (Gox), α‐amylase (AM) and xylanase (Xyl) on dough properties and bread quality, applying response surface analysis. Gox improved dough stickiness and bread crumb uniformity, but had a negative effect on specific volume. A positive synergist effect was observed combining Xyl and AM on specific volume and crumb firmness but this synergist effect was negative on crumb uniformity. Using the ‘desirability function’, two optimal formulations for the baking process were obtained. In the first optimisation, the combination of Gox 0.0026, Xyl 0.016 and AM 0.01 g per 100 g of flour will allow to obtain breads with high specific volume and low firmness. Second optimisation (Gox 0.0037, Xyl 0.0089 and AM 0.0105 g per 100 g of flour) will allow to obtain breads with 37% higher specific volume than control and, additionally, with low dough stickiness.  相似文献   

19.
The influence of fungal and bacterial -amylases on the texture and microstructure of dough and bread was investigated. Loaf specific volume, crumb porosity and texture properties were accepted as bread structure and texture characteristics. The microstructure analysis of dough and bread using light and scanning microscopy methods was performed.The changes in loaf specific volume, crumb porosity and texture properties showed different anti-staling activity of the enzymes used. The simultaneous action of enzyme addition and the fermentation process evoked significant changes in the microstructure of dough. The character of these changes depended on the kind of enzyme used. A substantial effect of both amylases on starch behaviour during bread baking and staling was also observed.  相似文献   

20.
 The possible relationships between biochemical characteristics [total starch, sugars, low-molecular-weight dextrins (LMWD), acetic and lactic acids, soluble solids and crumb-swelling power] and characteristics related to the quality of wheat bread (volume, texture and sensory quality scores) have been investigated. Variables influencing the possible interactions occurring were the type of flour (white and whole-wheat flours), the starter microorganism (Lactobacillus brevis, L. plantarum) and the type of process used to introduce the lactobacilli inoculum (sourdough, straight). The main factor explaining variability of data was related to sensory quality attributes and physical characteristics of the breads. The second factor was related to LMWD and the third to the acidity and lactic acid content of breads. The first factor permitted separation of the bread samples into two groups on the basis of flour extraction rate, whereas LMWD allowed differentiation between white breads made with sourdough or straight processes. Cluster analysis included the level of acidity and the lactic acid content as additional factors grouping control breads (without starter) together with breads made using a straight process. The best canonical correlation was established between the physical characteristics of breads and carbohydrates, soluble solids and crumb-swelling power. The first pair of canonical variables between two sets of experimental variables showed a squared correlation coefficient of 0.986. Received: 15 July 1996  相似文献   

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