Chia trace elements detection by neutron activation analysis / Detecção de elementos traço de chia por análise de ativação neutrônica

Chia 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.  

Determinação da composição mineral de subprodutos agroindustriais utilizados na alimentação animal, pela técnica de ativação neutrônica

This study aimed to analyze some agroindustrial by-products used to feed animals in order to identify the presence of the main minerals. Samples of cotton seed meal, rice, canola, soybean and wheat; fish meal, feather meal, meat meal, feather plus viscera meal; rinds of cotton, rice, orange; citrus pulp and tomato residue were collected in different sites of production of the by-products. The method of analysis used was the neutron activation followed by gamma ray spectrometry. The levels of minerals found in all samples were compared with the levels commonly found in forages. The mineral concentration, even those of the toxic elements, as As, Cd and Hg, was at low level and did not exceed the maximum tolerable levels for domestic animals.O presente trabalho teve como objetivo analisar alguns subprodutos agroindustriais utilizados na alimentação animal e identificar os principais minerais presentes. Amostras de farelos de algodão, arroz, canola, soja e trigo; farinhas de peixe, carne e penas + vísceras; cascas de algodão, arroz, laranja; bagaços de tomate e de laranja foram coletadas em diferentes locais de produção. O método analítico empregado foi a análise por ativação com nêutrons seguida de espectrometria gama. Os níveis de minerais encontrados em todas as amostras, inclusive aqueles considerados tóxicos, tais como As, Cd e Hg, não excederam os limites máximos permitidos em dietas para animais domésticos. Os valores obtidos foram comparados com os comumente encontrados em forragens