GABRIEL DE SOUZA CHIERENTIN
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Artigo IPEN-doc 27923 Impact of electron beam irradiation in potato starch films containing hibiscus aqueous extract2021 - TEIXEIRA, B.S.; CHIERENTIN, G.S.; DEL MASTRO, N.L.The development of starch films containing natural antioxidants is one alternative of active packaging. Starch is a well studied natural biopolymer that can be used for the development of biodegradable films because it presents a low cost, is easy to obtain and presents good ability to form films. Hibiscus sabdariffa, commonly known as roselle or red sorrel, is an annual her baceous sub shrub that contains many types of biocompounds, including organic and phenolic acids. The aim of the present work was to determine the influence of electron beam irradiation on potato starch film containing hibiscus extract. The aqueous hibiscu s solution was prepared by boiling for 3 min 1% w/ml dehydrated hibiscus flowers in 500 ml deionized water. The film forming solution was prepared by casting ( potato starch, 3% glycerol as plasticizer and the hibiscus solution) and irradiated in a 1.5 M eV electron beam accelerator Dynamitron II (Radiation Dynamics Inc.), with doses of 0, 20, 40 and 60 kGy. After drying some mechanical properties were measured. The tensile strength of the control films and the irradiated ones was established. There were n o significant differences among them. Hibiscus antioxidants were able to prevent the starch radiation degradation process caused by radiation induced free radicals.Artigo IPEN-doc 27865 Total phenolic compounds of irradiated chia seeds2021 - CHIERENTIN, G.S.; TEIXEIRA, B.S.; MASTRO, N.L.Chia seeds (Salvia hispanica L.) is a good source of oil, protein, dietary fiber, minerals and polyphenolic compounds. In order to study the influence of the processing methods on the content of phenolic compounds, the objective of this work was to evaluate the effect of gamma radiation, doses 0 (control), 5, 10 and 20 kGy, on the total phenolic compounds extracted from chia seeds. Seeds were first defatted and extracts produced with proper solvents. Total phenolic content was determined according to Folin-Ciocalteu’s method and the extraction solvents applied were ethanol 100%, ethanol 70%, ethanol 50%, methanol 100%, methanol 70% and methanol 50%. When using ethanol 100%, ethanol 70 %, ethanol 50%, methanol 100% and methanol 70%, the extraction yield was independent of the absorbed dose. With methanol 50%, the irradiation process affected positively the total phenolic yield from of chia seeds. In general, the absorbed dose as well as the nature of the solvent affected the extraction yield, although in a limited manner.Artigo IPEN-doc 27243 Chia trace elements detection by neutron activation analysis2020 - CHIERENTIN, GABRIEL de S.; ARMELIN, MARIA J.A.; MASTRO, NELIDA L. delChia seed is an ancient grain that is becoming popular in modern food regimen for their nutritional value and functional properties, although many tables of food composition do not provide complete information about it. Trace and ultra-trace elements are indispensable for human health as they are involved in biochemistry regulations, such as transport and oxygen activation, electron transport, catalytic center in oxide reduction processes, catalytic center in acid-base processes and structural function. For both diet assessment and prescription, reference values for trace elements as recommended daily intake, recommended dietary allowance and tolerable upper intake level were established. Instrumental neutron activation analysis (INAA) is a noble method to identify and quantify trace and ultra-trace elements that has high sensitivity for many elements, has little or no sample contamination, resulting in low blank values, has virtually no matrix effects and multi element capability. The aim of the present work was to identify and quantify by INAA mineral elements of chia seeds. The results showed higher content of Ca, K, Zn and Fe when compared with data from the literature obtained by other analytical methods. Besides that, using INAA was possible to detect elements that was not commonly verified with others measuring methods.