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Electron spin resonance (ESR) was used in order to study interaction of starch polysaccharides (amylose and amylopectin), their mixture and gelatinized potato starch with water molecules and lipids upon cooling. Different spin probes were used, on the one hand spin-labelled stearic acid (5-DSA), which limited lipids, and on the other hand the water soluble probe 4-hydroxy-2,2,6,6-tetramethylpiperidine-1- oxyl (Tempol), which was sensitive to changes in dynamic water phase associated with the temperature- induced polysaccharide gel formation. It was shown that interaction between gelatinized starches and lipids related to mainly on presence of amylose macromolecules in the system. On the other hand, interaction between amylopectin macromolecules and lipids takes place also.
The main structural element of biological membranes is a liquid-crystalline lipid bilayer. Other constituents, i.e. proteins, sterols and peptides, either intercalate into or loosely attach to the bilayer. We applied a molecular dynamics simulation method to study membrane systems at various levels of compositional complexity. The studies were started from simple lipid bilayers containing a single type phosphatidylcholine (PC) and water molecules (PC bilayers). As a next step, cholesterol (Chol) molecules were introduced to the PC bilayers (PC-Chol bilayers). These studies provided detailed information about the structure and dynamics of the membrane/water interface and the hydrocarbon chain region in bilayers built of various types of PCs and Chol. This enabled studies of membrane systems of higher complexity. They included the investigation of an integral membrane protein in its natural environment of a PC bilayer, and the antibacterial activity of magainin-2. The latter study required the construction of a model bacterial membrane which consisted of two types of phospholipids and counter ions. Whenever published experimental data were available, the results of the simulations were compared with them.
Saturated aqueous solutions of D-glucose, D-fructose and sucrose were blended with solid granules of corn, waxy corn and tapioca starches. Systems deficient in water were obtained, properties of which were studied by dynamic rheological measurements. The properties of systems obtained at different proportions of saturated sugar solutions to starch were characterized. It was concluded that desired rheological properties (fluidity of blends) can be achieved by adjusting relevant quantity of plasticizers (different sugars and water). Similarly, by adjusting the quality and quantity of plasticizers, the phenomenon of "magic trick" (viscoelastic behaviour) can be achieved in the studied systems, however, that property is manifested in a very narrow range of starch-to-saturated sugar solution ratio. For all systems under study, the quantity of saturated solutions of relevant sugars, needed to achieve plasticity of each systems, was depicted. It was also concluded that in order to achieve plasticity with tapioca starch granules, for each 2 g of this starch 1.83 and 1.99 g of saturated solution of D-glucose and sucrose, respectively, are needed. In order to achieve plasticity with granules of waxy corn starch - 2.63 and 2.35 g, respectively, and with granules of corn starch - 3.09 and 2.5 g of saturated solutions of D-glucose and sucrose, respectively, are needed. The systems containing saturated solutions of D-fructose have different relationships. In order to achieve plasticity of blends containing corn, waxy corn and tapioca starch, for each 2 g of starch 2.14; 2.13 and 2.33 g, respectively, of saturated fructose solution is needed.
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