Resumo Este trabalho descreve a análise de tecidos comestíveis de frango como coração, fígado e moela, crus e cozidos com temperos em diferentes panelas (panela de ferro, panela de alumínio e panela de alumínio batido) comumente utilizadas no Brasil. A digestão ácida assistida por radiação micro-ondas, com utilização de ácido nítrico diluído, foi empregada para decomposição das amostras. Os teores dos elementos metálicos Al, Ca, Cu, Fe, Mn e Ni foram determinados por Espectrometria de Emissão Óptica com Plasma Induzido por Micro-ondas. A comparação dos teores de Fe obtidos também por Espectrometria de Absorção Atômica em Chama mostrou uma boa exatidão do método. Os limites de quantificação para os analitos avaliados ficaram abaixo de 0,011 mg kg-1, mostrando detectabilidade adequada. As cocções das amostras nas diferentes panelas utilizadas promoveram um aumento dos teores de cinzas e proteínas e uma diminuição dos teores de umidade. A Análise de Componentes Principais e os diagramas de caixa mostraram que as variáveis Ca e Fe apresentaram as maiores variações entre as amostras, seguidas pelas variáveis Al e umidade. As variáveis Al, Cu, Mn, Ni, cinzas e proteínas apresentaram comportamento semelhante após a cocção nos três tipos de panela empregados. A amostra de fígado cozida tanto na panela de ferro quanto na panela de alumínio batido apresentou teores similares de Fe, enquanto as amostras de coração e moela apresentaram teores similares de Ca após cocção nas mesmas panelas.

Abstract This work describes the analysis of different chicken tissues (gizzard, heart, and liver) both raw and cooked with seasonings in different types of cooking pots (iron pot, , aluminum pot and hammered aluminum pot) commonly used in Brazil. The samples were decomposed using microwave-assisted digestion with diluted nitric acid; and the contents of Al, Ca, Cu, Fe, Mn and Ni were determined using Microwave Induced Plasma Optical Emission Spectrometry (MIP OES). The Fe content was also determined by Flame Atomic Absorption Spectrometry, and the comparison showed good accuracy of the method. The limits of quantification were below 0.011 mg kg-1, showing adequate detectability. Cooking in the different pots increased the ash and protein contents as well as decreased the moisture content. Box-plot and Principal Components Analysis showed that Ca and Fe contents present the largest variations in the samples, followed by Al and moisture. The variables Al, Cu, Mn, Ni, ash, and protein presented similar behavior after cooking in all different pots. In addition, liver cooked in both iron and hammered aluminum pots presented similar Fe contents, while gizzard and heart showed similar Ca contents.

Abstract Nutritionally, cheese and other dairy products have been highlighted especially as a calcium source. Access to minerals is dependent on variables related to diet, lifestyle, and also the health status. This study aimed to evaluate the bioaccessibility and calcium partition in Minas Padrão cheese over its ripening period for experimentally obtained samples. The cheese of the study has been manufactured using two different technologies (A and B). Also to evaluate the evolution of pH over cheese ripening and the influence of calcium partitions in its bioaccessibility along the cheese ripening period. The mean values found for total calcium content were (549 mg⋅100 g-1 – A and 644 mg⋅100 g-1 – B). For calcium in the aqueous phase on average 460 mg⋅100 g-1 – A and 404 mg⋅100 g-1 – B. These and other changes found are possibly due to physicochemical and biochemical changes, especially with respect to pH variations. Calcium bioaccessibility decreased in the beginning and then incresed in the end of the ripening period. The results obtained in this work hopefully may allow further studies and the development of products in which calcium bioaccessibility might be indicated on the product`s label accordingly to its ripening time.

Abstract A 32 factorial design was employed to develop an in vitro digestion method for estimation of Fe bioaccessible fractions in cooked chicken meat. The effects of sample size and the in vitro bioaccessible fractions of this essential element were evaluated. A sample preparation method employing a microwave assisted digestion with dilute nitric acid was used prior to total Fe determination. For the bioacessibility studies, the optimized procedure employed 7.5 g of sample and 6% w/v of an acid pepsin solution. This procedure was applied to two kinds of chicken meat samples: breast and liver. Flame Atomic Absorption Spectrometry was used to determine total and bioaccessible (chyme or soluble portion) levels of iron in the samples. With respect to total Fe content, the bioaccessible fractions of Fe found in these samples were around 23% and 56 %, for breast and chicken liver, respectively. The chicken liver sample showed the highest total (400 ± 10 mg kg-1) and bioaccessible Fe contents (223 ± 18 mg kg-1) and stands out as a good source of this micronutrient.