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Protein and gluten content, Zeleny Index, farinograph and alveograph properties are widely used to determine the protein quantity and the quality of flour. Mixolab can be used to measure dough characteristics such as protein quality, enzymatic activity and starch retrogradation in a single test. The objective of this study was to determine the variability of and the relationship among the farinograph and alveograph properties and mixolab parameters which characterise the protein complex. Tests were performed on 76 samples of wheat flour type 550 and type 750 produced in Poland. Wheat flour type 750 was characterised by significantly higher protein content, farinograph water absorption, dough development and stability time. Rheological properties of dough tested by mixolab differed with regard to the type of flour. Wheat flour type 750 was characterised by higher water absorption and time T1 and lower torque in points C2, C12min, C14min, C16min than wheat flour type 550. Higher correlation coefficients were obtained between farinograph parameters (stability and softening) and mixolab torque in points C8min, C10min, C12min, C14min than in point C2 which is a mixolab parameter commonly used to determine protein weakening. Mixolab values can be used to elaborate predictive models for estimating values of farinograph water absorption, dough stability, dough softening, alveograph baking strength (W) and P/L index.
Two flour types (unpolished flour and polished one) and flour textures (grits and fine) of five cereal grains made up of millet, rice, wheat, sorghum and maize were evaluated under laboratory conditions for their susceptibility and progeny development in Tribolium castaneum in hot dry and cool humid seasons. T. castaneum thrived better during the cool humid season than the hot dry season. Polished flour was less susceptible to infestation and supported lower population of the beetles than unpolished flour. Index of susceptibility was 19.65-20.76% in unpolished flour and 18.89-19.76% in polished flour. The number of progeny that developed were 102.6-135.1 and 98.2-121.4 in unpolished and polished flours, respectively. Similarly, grit flour was significantly less susceptible than fine flour in both seasons. Rice, wheat and sorghum flours were less susceptible and supported significantly lower populations of T. castaneum than millet and maize flours in both seasons. Polished wheat flour supported least progeny number than the flour types of the other cereal grains. Conversely, significantly higher number of progeny developed in polished flour of millet and maize and unpolished flour of wheat. Millet fine flour and maize fine or grit flours were significantly more susceptible to infestation than flours of the other cereal grains.
Materiałem badawczym było ziarno 11 odmian pszenicy ozimej: Begra, Panda, Olcha Almari, Gama, Wilga, Emika, Kobra, Roma, Jawa, Juma, ze zbioru w latach 1994-1996. Stwierdzono, że oceniane odmiany różniły się wartościami badanych cech. Małe różnice zaznaczyły się tylko w końcowej temperaturze i czasie kleikowania mąki. Mąka pszenna charakteryzowała się niską aktywnością a-amylazy, mierzonej liczbą opadania. Na ilość glutenu, liczbę sedymentacji i wartość wypiekową mąki korzystnie wpływała zawartość białka ogółem i aktywność α-amylazy. Stwierdzono, że ziarna skrobi badanych odmian pszenicy odznaczały się dużą trwałością w czasie ogrzewania w temperaturze 95°C, a po ochłodzeniu do 50°C kleiki skrobiowe trudno retrogradowały. Chleby wypieczone z mąki pszennej różniły się objętością, nadpiekiem i porowatością miękiszu.
Gari fortified with Bambara Groundnut Flour (BGF) was assessed for its proximate composition, functional properties, sensory evaluation and Rheological properties. Four samples; 100% gari (coded SLY), 90 % gari with 10 % BGF (coded ATS), 85 % gari with 15 % BGF (coded FEA), and 80 % gari with 20 % BGF (coded ROT) were examined for the parameters listed above. The proximate analysis showed that the protein content ranges between 0.98-4.68 %, fat content 1.10-2.60 %, ash content 1.82-2.90 %, crude fibre 2.30-2.42 %. This showed an increase on addition of BGF while the carbohydrate content ranges between 78.20-83.5 %, moisture 11.60-12.6% and acidity 0.40-0.60, all showed a decrease in value on adding BGF. Rheological value showed that the peak viscosity ranges between 106.17-177.17, trough viscosity 98.33-161.00, breakdown 7.83-16.71, final viscosity 150.50-251.67, set back 52.17-90.67 and pasting time between 6.87-6.93. All these varied inversely with the quantity of BGF added. Pasting temperature showed slight variation which was not dependent on the amount of BGF added. It ranges from 79.2-80.02 °C. Sensory evaluation showed that there were significant differences in the samples examined.
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The investigated types of wheat flour were characterised by varied chemical composition. The sorption properties were assessed on the basis of monolayer capacity, sorption specific surface, total capacity of capillaries in the area of capillary condensation, the most prob-able capillary radius and radius of capillaries subject to filling in the first phase of condensation. The initial data were obtained by the static-desiccation method at 20ºC and 30ºC. The results revealed that the effect of temperature growth on sorption properties of flour is not explicit, although at higher ambient temperature a significant differentiation of sorption properties of individual types of flour is observed, most probably determined by their chemical composition. Sorptivity of wheat flour is correlated to the protein content. On the other hand, the capillary structure is not a feature differentiating individual types of flour.
Wyroby ciastkarskie stanowią popularną wśród konsumentów grupę produktów spożywczych. Na rynku istnieje gama produktów otrzymanych głównie z mąki pszennej i z dodatkiem płatków bądź otrąb zbożowych, natomiast nie spotyka się ciastek otrzymanych w całości z mąki amarantusowej, dyniowej, jęczmiennej czy żytniej. Celem pracy było porównanie cech sensorycznych, akceptowalności konsumenckiej i właściwości mechanicznych ciastek kruchych wypieczonych z handlowej mąki amarantusowej, jęczmiennej, dyniowej i żytniej, z ciastkami otrzymanymi z mąki pszennej. W ciastkach oznaczono twardość, wykonując test trójpunktowego łamania, przy użyciu analizatora tekstury TA.XT2plus. Przeprowadzono ocenę sensoryczną, badania akceptowalności konsumenckiej przy użyciu 9-stopniowej skali hedonicznej, a także profil smakowo-zapachowy przy użyciu skali graficznej. Zastąpienie mąki pszennej przez inne mąki wpłynęło na zmianę parametrów tekstury i walorów organoleptycznych ciastek. Zamiana mąki pszennej na amarantusową i dyniową spowodowała zmniejszenie twardości i wilgotności ciastek. Ciastka sporządzone z mąki jęczmiennej i żytniej charakteryzowały się zbliżoną twardością w dniu wypieku i podczas początkowego okresu przechowywania. Zasadnym jest wprowadzenie do produkcji ciastkarskiej mąki dyniowej, jęczmiennej czy żytniej jako substytutu mąki pszennej.
Buckwheat seeds are an important pseudocereal used as flour in baking industry. Also hulls, a waste material produced in the de-hulling process is of certain interest. Hemicelluloses were isolated from buckwheat hulls. They were characterised and shown to be of the glucuronoxylan type. Their effect upon rheological properties of gels of corn starch with varying amount of hemicelluloses (0.3%; 0.5%; 0.7% and 1.0%) is described. The rheological properties of the blends were investigated using the Brabender viscograph and Rheotest 2 viscograph. At the same pasting temperature, pastes containing an optimum of hemicelluloses (0.5-0.7%), exhibited the highest viscosity and stability against mechanical stress. At this optimum concentration, hemicelluloses increased substantially the apparent viscosity of the pastes at low and high shear rates and this trend was observed also with increase in temperature. Effect of the hemicellulose addition to corn starch on retrogradation of the pastes was studied in the refrigeration as well freeze-thaw processes. A minimum addition of hemicelluloses (0.3%) significantly affected the syneresis of starch.
The big starch grains of type A >10 µm in diameter are synthesised in cereal kernel until it reaches the early-waxy phase of maturity. In matured kernels 80% of total starch grains make up small grains of type B. It is known from earlier research that for creating the bread crumb structure big starch grains are needed because they swell and react with denatured gluten. To improve the above mentioned proportions 5 and 10% of wheat, rye and barley starches were added to the baking of wheat breads from flour type 550. The starches were separated from kernels harvested in early and late-waxy phases. All breads were baked by direct method according to the same recipe. The volume of baked breads was measured, the sensory evaluation done and the texture profile of bread crumb was performed by TA-XT2 analyser. During three day storage hardness, springiness, cohesivness, gum- miness, chewiness and resilience of bread crumb were estimated. Starch additives did not affect the organoleptic value and the largest volume displayed breads with 3% starch additive from kernels in early-waxy phase of maturity irrespective of cereal species. The origin and amount of added starch did not influence the texture parameters of bread with the exception of crumb hardness. All breads with starch additives were characterized by lower crumb hardness on the day baking and during three day storage in comparison with the standard bread. The most advantageous was an addition of 3 % of wheat and rye starches originating from kernels reaped in early-waxy phase of maturity. High resistance of such starch grains to swelling and pasting may have been responsible for that result (confirmed by DSC examination). Similar results can be obtained, for starch from mature kernels, only with the usage of certain inhibiting starch swelling substances in dough making. Usage of starches from wheat and rye kernels reaped in early-waxy phase of maturity eliminates addition of starch swelling inhibitors. The starch originating from grains of the early-waxy phase of maturity can be used as natural bread improver.
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