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The differences and similarities of endosperm microstructure in different places of vitreous and mealy kernels of wheat of different origin and hardness were evaluated. Kernels of seven T. durum and five T. aestivum cultivars of different origin, protein content, and mechanical resistance were investigated. Five points on the kernel cross-section surface were selected for endosperm microstructure observation with scanning electron microscope JEOL 5200. Digital image analysis (DIA) was used for quantification of endosperm micro structure by transformation of the microscopic pictures and measuring the area and number of transformed image elements. Type of wheat (T. durum and T. aestivum), type of kernel (vitreous and mealy) and sampling place on the cross-section surface influenced the endosperm microstructure statistically significantly. Despite high standard deviations within the data set for single kernel (from 5 to 25%), differences in vitreous and mealy kernels of particular wheat cultivars were evidently clear. Despite differences between vitreous and mealy kernels, types of wheat were very well classified in discriminant analysis. It should be said, however, that the differences in microstructure of mealy and vitreous kernels within the cultivar are smaller than those in the microstructure of different wheat types i.e. T. durum and T. aestivum.
In the presented work the effects of 3-year own investigations relative to technological usability of potato tubers of parental cultivar and its genetically-modified clones were recapitulated. Potato tubers of cultivar Irga were transformed with viral genome sequences in order to improve their resistance to a necrotic strain of potato virus Y (PVYN) at the Institute of Biochemistry and Biophysics, Warsaw, and tubers of the transgenic clones were produced at the Plant Breeding and Acclimatisation Institute, Młochów, in 2000-2002. At the first stage, the variability of parameters characterizing raw material quality was determined. The characteristics of physical properties (size, shape, and mechanical resistance of tubers), microstructure, and content of main chemical constituents (starch, protein, ash, ascorbic acid, glycoalkaloids: α-solanine and α-chaconine) of 15 genetically-modified clones were investigated during three successive years. Tubers of these GM clones were next subjected to culinary processing (microwaving, cooking, and frying) and physico-chemical changes, which are decisive for texture formation and texture properties of end-use product, have been investigated and technological usability of GM potatoes was established. In this work, due to a considerable number of collected data, the final results were presented as means for modification group or, in two cases, as results relative to single clones representative for modification groups. Analysis of variability of physical and chemical parameters studied for the raw and heat-treated potato tubers enabled classifying Irga and its genetically-modified clones as similar, and did not allow distinguishing a clone of special usability for heat processing.
Apple pectin and α-amylase (Termamyl) were used as anti-staling agents of pan bread. Additions of pectin and a-amylase were 0.5, 1.0, 1.5, 2.0% and 0.3, 0.6, 1.0, 1.5 KNU, respectively. Breads were stored at room temperature for 6 days. Baking quality, alkaline water retention capacity, texture properties, porosity, and microstructure of bread crumb were studied. Loaf volume and specific loaf volume of bread were improved upon low level treatments of pectin and a-amylase. Addition of both pectin and α-amylase resulted in weakened crumb structure and porosity inreasing. It could be observed that the control bread had the lowest values of alkaline water retention capacity (AWRC), being 232, 190 and 175%, respectively, at 1, 3 and 6 day of storage. Addition of pectin and α -amylase always caused noticeable increase in the AWRC values. It was proved that during storage crumb hardness increased, but elasticity, cohesiveness, guminess, volume recovery coefficient, and porosity decreased for all examined breads. The values of texture parameters for the treated breads have never exceeded those for control bread, except 6-day-stored bread with 2.0% pectin. Microscopic analysis of crumb macro- and microstructure revealed remarkable differences in control and treated, fresh and stored breads and supported well obtained quality data. The results showed that apple pectin and α-amylase were effective in softening of bread crumb and reducing staling rate. It is found that apple pectin and α-amylase can be effectively used to improve baking quality and retarded staling of bread up to 1.5% and 0.6 KNU, respectively.
W niniejszej pracy przedstawiono wyniki badań cech geometrycznych, masy nasion, prędkości krytycznej unoszenia nasion w pionowym strumieniu powietrza oraz kąta tarcia zewnętrznego 32 odmian i rodów lędźwianu siewnego pochodzących z różnych krajów europejskich. Określono różnice w wartościach analizowanych wyróżników dla poszczególnych odmian/ rodów tych nasion, a także podjęto próbę uchwycenia zależności między nimi. Na podstawie przedstawionych wyników i ich statystycznej analizy stwierdzono, że między wartościami średnimi cech poszczególnych odmian/rodów nasion lędźwianu siewnego występują istotne różnice. Występowanie licznych grup jednorodnych świadczy o dużej zmienności losowej rejonizacji upraw, z których pochodziły próby.
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