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Potatoes, especially colored, are perceived as a valuable source of bioactive compounds, and they are also an important raw material for starch production. There is virtually no information about starch from colored potatoes grown in Central Europe. Therefore, starches from light and colored potato varieties are isolated, and their particle size distributions, molecular masses, phosphorus content, gelatinization properties, water binding capacity, and solubility are analyzed. It is found that the mean and minimum granule size is similar for all investigated varieties, but colored varieties have larger granules. Moreover, starches isolated from colored potatoes are characterized by a higher phosphorus content than those isolated from light ones. It is shown that the solubility and water‐binding capacity of starch from colored potatoes is greater than that of light flesh, especially at higher temperatures. Starches from light flesh potatoes are characterized by significantly higher gelatinization enthalpy values than those from colored potatoes. [ABSTRACT FROM AUTHOR]

The aim of this paper was the study of the rheological instability (thixotropy and/or antithixotropy) of normal potato starch (NPS) pastes depending on their concentration (2–5%) and degree of pasting. Flow curves with hysteresis loops, apparent viscosity at constant shear rate and in-shear structural recovery tests were carried out. Granule size profiles, the pasting characteristic of corresponding starch suspensions and the transmittance of the pastes, the molecular weights and polydispersity of granular starch and its pastes prepared at 80, 95 and 121 °C were also studied. The degree of pasting was dependent on the temperature and the concentration and influenced strongly the rheological behavior of the pastes. All pastes belonged to the non-Newtonian liquids thinned by shear and were rheologically unstable to the various extent. Thixotropic properties were connected to the size and the number of the starch granules in the pastes as well as depended on the measuring method used. In the 2 and 3% samples pasted at 80 °C the swelling of the granules prevailed their destruction (thixotropy was observed). In the other samples the destruction predominated the swelling (antithixotropy observed). [ABSTRACT FROM AUTHOR]