Otimização de métodos analíticos para determinação de elementos essenciais e não essenciais em farinha de mandioca, trigo e milho consumida na cidade de Aracaju/SE

• Ano de defesa: 2014
• Autor(a) principal: Correia, Felipo Obed
• Orientador(a): Araújo, Rennan Geovanny Oliveira
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Programa de Pós-Graduação: Pós-Graduação em Química
• Palavras-chave em Português: Química analítica; Análise espectral; Farinhas; Análise de alimentos; Composição de alimentos
• Palavras-chave em Inglês: Analytical chemistry; Food; Meal; Spectrum analysis
• Área do conhecimento CNPq: CNPQ::CIENCIAS EXATAS E DA TERRA::QUIMICA
• Link de acesso: https://ri.ufs.br/handle/riufs/6085

In this work analytical methods were optimized for the determination of inorganic constituents in cassava flours, corn flour and wheat flour using atomic spectrometry techniques. Factorial design techniques were applied to the optimization of the procedure of microwave assisted digestion of the samples and operating conditions of the inductively coupled plasma optical emission spectrometer (ICP OES). The operating conditions of the inductively coupled plasma mass spectrometer (ICP-MS) were optimized using univariate experimental designs. The proposed analytical methods showed acceptable sensitivity for the determinations, with limits of quantification (LOQ) for Al, Ba, Ca, Cd, Co, Cu, Fe, K, Mg, Mn, Ni, P, S, Sb, Sr and Zn, ranging from 0.02 to 23 Ýg g-1. The accuracy of the analytical methods were confirmed by analysis of certified reference materials of rice flour (NIST 1568a), wheat flour (NIST 1567a) and tea leaves (NCS DC 73351), with concordances between 81 ¡Ó 1 and 118 ¡Ó 12% (n = 3). Precision was expressed as the relative standard deviation (RSD) and all values are better than 14% (n = 3). The proposed methods were applied to determine the mineral composition of 38 samples of flour. The macroconstituents in the samples were Ca, K, P, Mg and S at concentrations ranging from 2.72 ¡Ó 1.09 (Ca) and 4253 ¡Ó 103 Ýg g-1 (K). For microconstituents and trace elements such as Ba, Cd, Co, Cu, Fe, Mn, Sr and Zn concentrations varied between 0.02 ¡Ó 0.01 (Sr) and 65.5 ¡Ó 9.7 Ýg g-1 (Fe). Exploratory analysis techniques were applied in order to characterize the cassava flours, corn flour and wheat flour. The formation of three distinct groups type of flour was observed according to the each elementary composition. As food, wheat flour showed the highest concentrations for Cu, Fe, Mn, P, S and Zn, and represent 35% of the recommended daily intake (IDR) established for Fe and Mn.