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Abstract(s)
No presente trabalho determinaram-se os teores dos carotenoides, α-caroteno, β-caroteno, β-criptoxantina, licopeno, luteína e zeaxantina presentes em amostras, de produtos hortícolas e pratos compostos representativos da alimentação da população portuguesa, recolhidas no âmbito do projeto TDSEXPOSURE (Total Diet Stu dy Exposure – Estudo de dieta total para avaliação da exposição). Os resultados obtidos são um contributo para a avaliação da ingestão de carotenoides em Portugal.
As amostras foram sujeitas a um procedimento analítico validado que incluiu etapas de extração, assim como de saponificação, quando o teor de gordura e/ou a presença de ésteres de carotenoide o justificou.
A determinação dos analitos foi realizada através do método de cromatografia líquida de alta eficiência (HPLC) de fase reversa comdetetor DAD-UV/Vis e, a sua quantificação foi feita através de calibração externa e recorrendo também a um padrão interno.
O desempenho do método analítico foi avaliado com dois tipos de materiais de referência, o material de referência certificado (NIST 2383) e o material de referência interno preparado no laboratório. Os resultados obtidos para z-score permitiram concluir que os valores medidos são exatos.
O processo de homogeneização das amostras foi também avaliado estudando a homogeneidade da matriz alimentar tomate com pele e grainhas. A análise estatística dos resultados permitiu confirmar a homogeneidade das amostras.
Os carotenoides que se encontraram na maioria das amostras foram o β-caroteno (0,018-14 mg/100 g) e a luteína (0,0014-8,2 mg/100 g). Em 25% das amostras não foi detetado qualquer carotenoide.
O estudo sobre o efeito da sazonalidade no teor de carotenoides em produtos hortícolas recolhidos em duas estações do ano (outono e inverno) evidenciou alterações no teor de β -caroteno no feijão-verde, de luteína na couve-flor e de zeaxantina no pimento.
A determinação da atividade pró-vitamina A evidenciou um maior valor de equivalentes de retinol (RE) para a cenoura (2710 µg/100 g).
Abstract: In the present work, the carotenoids, α-carotene, β-carotene, β-cryptoxanthin, lycopene, lutein and zeaxanthin present in samples, in particular vegetables and composite dishes representative of the Portuguese population diet, were collected as part of theTDSEXPOSURE project (Total Diet Study Exposure). The results are a contribution to the evaluation of carotenoid intake in Portugal. The samples were subjected to a validated analytical procedure that included extraction steps, as well as saponification st eps, when the fat content and/or the presence of carotenoid esters justified it. The determination of the analytes was carried out using the reverse phase high performance liquid chromatography (HPLC) method with DAD-UV / Vis detector and quantification was done through external calibration and also using an internal standard. To evaluate the performance of the analytical method, two types of reference materials were analyzed, the certified reference material (NIST 2383) and the internal reference material prepared in the laboratory. The results obtained for z-score allowed to conclude that the measured values are exact. The homogenization process of the samples was evaluated by studying the homogeneity of the tomato food matrix with skin and seeds. Statistical analysis confirmed that the homogenization process was adequate. The carotenoids found in most of the analyzed samples were β-carotene (0.018-14 mg/100 g) and lutein (0.0014-8.2 mg/100 g). In 25% of the samples no carotenoid was detected. The effect of seasonality on the carotenoid content in vegetables collected in two seasons of the year (autumn and winter) showed changes in β-carotene content in green beans, lutein in cauliflower and zeaxanthin in the pepper. The activity evaluation as pro-vitamin A showed the highest value of retinol equivalent (RE) for carrot (2710 μg/100 g).
Abstract: In the present work, the carotenoids, α-carotene, β-carotene, β-cryptoxanthin, lycopene, lutein and zeaxanthin present in samples, in particular vegetables and composite dishes representative of the Portuguese population diet, were collected as part of theTDSEXPOSURE project (Total Diet Study Exposure). The results are a contribution to the evaluation of carotenoid intake in Portugal. The samples were subjected to a validated analytical procedure that included extraction steps, as well as saponification st eps, when the fat content and/or the presence of carotenoid esters justified it. The determination of the analytes was carried out using the reverse phase high performance liquid chromatography (HPLC) method with DAD-UV / Vis detector and quantification was done through external calibration and also using an internal standard. To evaluate the performance of the analytical method, two types of reference materials were analyzed, the certified reference material (NIST 2383) and the internal reference material prepared in the laboratory. The results obtained for z-score allowed to conclude that the measured values are exact. The homogenization process of the samples was evaluated by studying the homogeneity of the tomato food matrix with skin and seeds. Statistical analysis confirmed that the homogenization process was adequate. The carotenoids found in most of the analyzed samples were β-carotene (0.018-14 mg/100 g) and lutein (0.0014-8.2 mg/100 g). In 25% of the samples no carotenoid was detected. The effect of seasonality on the carotenoid content in vegetables collected in two seasons of the year (autumn and winter) showed changes in β-carotene content in green beans, lutein in cauliflower and zeaxanthin in the pepper. The activity evaluation as pro-vitamin A showed the highest value of retinol equivalent (RE) for carrot (2710 μg/100 g).
Description
Trabalho final de mestrado para obtenção do grau de mestre em Engenharia Química e Biológica
Keywords
Carotenoides Carotenoids Homogeneidade Homogeneity Sazonalidade Seasonality Produtos hortícolas Vegetables Pratos compostos Composite dishes Estudos de dieta total em Portugal Total study diet in Portugal HPLC
Citation
ALMEIDA, Ana Catarina Ruas de - Avaliação analítica do teor de carotenoides em produtos hortícolas e pratos compostos representativos do consumo da população portuguesa. Lisboa: Instituto Superior de Engenharia de Lisboa, 2017. Dissertação de mestrado.
Publisher
Instituto Superior de Engenharia de Lisboa