BRUNA SAPORITO TEIXEIRA
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Artigo IPEN-doc 29816 Effects of electron beam irradiation on ozone-modified potato starch film2023 - TEIXEIRA, BRUNA S.; MASTRO, NELIDA L. delFunctional starch-based films are promising materials being developed at different laboratories. Native and modified starches are two materials being employed for this purpose. Chemical modification of starch generally involves esterification, etherification, or oxidation of the units that make up the starch polymers. Ozone constitutes an advanced oxidation technology for starch modification. In this work, properties of two kinds of materials - ozone-modified potato starch and irradiated ozone-modified potato starch-based films - were evaluated. Potato starch films were submitted to electron beam irradiation with doses up to 40 kGy. Films were produced by the casting technique using native and ozonated potato starch, glycerol as the plasticizer, and water as the solvent, and characterized in term of solubility and absorption of water, determination of oxygen gas transmission rate and Fourier Transform infrared Spectroscopy (FTIR) analysis. Ozone-modified potato starch presented strong alterations on pasting properties, with drastic reduction of viscosity values, water solubility and oxygen permeability. The data reported in this work contribute to the understanding of the ozone-modification process on starch and suggests further possibilities of industrial applications of ozonation on biomaterials.Artigo IPEN-doc 24329 Comparison of gamma radiation effects on natural corn and potato starches and modified cassava starch2018 - TEIXEIRA, BRUNA S.; GARCIA, RAFAEL H.L.; TAKINAMI, PATRICIA Y.I.; DEL MASTRO, NELIDA L.The objective of this work was to evaluate the effect of irradiation treatment on physicochemical properties of three natural polymers, i.e. native potato and corn starches and a typical Brazilian product, cassava starch modified through fermentation-sour cassava- and also to prepare composite hydrocolloid films based on them. Starches were irradiated in a Co-60 irradiation chamber in doses up to 15 kGy, dose rate about 1 kGy/h. Differences were found in granule size distribution upon irradiation, mainly for corn and cassava starch but radiation did not cause significant changes in granule morphology. The viscosity of the potato, corn and cassava starches hydrogels decreased as a function of absorbed dose. Comparing non-irradiated and irradiated starches, changes in the Fourier transform infrared (FTIR) spectra in the 2000-1500 cm(-1) region for potato and corn starches were observed but not for the cassava starch. Maximum rupture force of the starch-based films was affected differently for each starch type; color analysis showed that doses of 15 kGy promoted a slight rise in the parameter b* (yellow color) while the parameter L* (lightness) was not significantly affected; X-ray diffraction patterns remained almost unchanged by irradiation.