Browsing by Author "Donard, Olivier"
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- Análise multielementar e quimiometria na autenticidade de alimentos: Pera RochaPublication . Coelho, Inês; Matos, Ana; Teixeira, Rita; Nascimento, Ana; Bordado, João; Donard, Olivier; Castanheira, IsabelA combinação da análise multielementar com a técnicas de quimiometria utilizadas permitiu agrupar as amostras de acordo com a sua região de origem, contribuindo para a sua autenticidade assim como para um maior conhecimento da sua composição nutricional.
- Characterization of inorganic contaminants present in rice varieties consumed in PortugalPublication . Coelho, Inês; Gueifão, Sandra; Vacchina, Veronique; Donard, Olivier; Castanheira, IsabelRecent data shows that Portugal has a rice consume of 15.8 kg/capita/year, the largest in Europe. The Sado estuary, located in the West Coast of Portugal, is a major area for rice production in Portugal. Although this area is partially classified as a natural reserve, it is also threatened by many sources of anthropogenic pressure and runoff from agriculture grounds, originating a moderately contaminated estuary in some hot-spot areas. The present work aims at evaluating the level of inorganic contaminants present in different rice varieties including whole grain, white rice, husk and bran. A total of 33 samples were obtained from Sado region and from distribution stores. Contents in manganese, copper, zinc, vanadium, chromium, cobalt, nickel, arsenic, selenium, strontium, cadmium and lead, were evaluated using an ICP-MS. Samples with the highest content of arsenic, were analyzed for arsenic speciation by coupling an HPLC to the ICP-MS. Samples were analyzed in compliance with the internal quality criteria established by the laboratory. In most samples levels of lead, cadmium, cobalt, and vanadium were below or near to the LOQ. Arsenic content varies between 98 and 250 µg/kg. Speciation data, showed that the species present were mainly arsenite (AsIII), representing about 80% of total arsenic, and dimethylarsinic acid (DMA). After comparing this data with other analytical results used in risk assessment studies we can infer that inorganic contaminants in samples are not a matter of concern. This study also shows the need of powerful analytical techniques with very low detection limits to measure inorganic contaminants in foods.
- Combining multielement analysis and chemometrics to trace the geographical origin of Rocha pearPublication . Coelho, Inês; Matos, Ana Sofia; Teixeira, Rita; Nascimento, Ana; Bordado, João; Donard, Olivier; Castanheira, IsabelThis work aims at characterizing the mineral profile of a Portuguese variety of pear, Rocha pear, and study the relationship between the nutritional profile and geographical origin. Multielement analysis of twenty-four elements (Al, As, B, Be, Ca, Cd, Co, Cr, Cu, Fe, K, Li, Mg, Mn, Mo, Na, Ni, P, Pb, Se, Sn, Sr, Tl, Zn) was performed using an ICP-MS and ICP-OES, on 50 samples originating from two regions, one with Protected Designation of Origin (PDO), known as “Pera Rocha do Oeste”, and the other without (nPDO). Correlation analysis was performed to check for potential relationships between elements. Results from PDO and nPDO regions were compared using chemometric tools, namely Principal Component Analysis, Hierarquical Cluster Analysis and Linear Discriminant Analysis (LDA). The predictive model, built and validated, classified samples according to their regional origin with 100% accuracy. The present study shows that multielement analysis combined with the appropriate statistical tools can be a valuable contribution from the identification of the geographical provenance of Rocha Pears. It provides important nutritional information regarding the mineral composition of Rocha pears, not available until know, promoting the linkage between the nutritional profile and geographical origin, filling the gap of absent values in FCDBs.
- Multielement fingerprinting, isotope ratios and chemometrics as tools to trace the geographical origin of winePublication . Coelho, Inês; Matos, Ana Sofia; Nascimento, Ana; Bordado, João; Donard, Olivier; Epova, Ekaterina; Barre, Julien; Berali, Sylvain; Castanheira, IsabelThe aim of the present work is to develop a chemical fingerprint using multielement analysis and isotope ratios, for tracing the geographical origin of Douro and Port wines. Both wines are produced within the Douro region, located in northeastern Portugal. Although the terroir is the same the fermentation of Port Wine is interrupted with the addition of “Aguardente Vínica” (alcohol distilled from wine) which alters the sweetness of the wine according to when it is added. Thirty samples of wine were supplied by the Instituto dos Vinhos do Douro e do Porto. Samples were digested using closed vessel microwave digestion. Multielement analyses were carried out, in triplicate, in compliance with NP EN ISO/IEC 17025. Inductively Coupled Plasma Mass Spectrometry (ICP-MS) was used for the determination of 25 elements (Li, Be, B, Al, Cr, Mn, Co, Ni, Cu, Zn, As, Se, Rb, Sr, Mo, Cd, Sn, Tl, Pb, Fe, Mg, Ca, Na, P and K). The digests were further purified for strontium isolation and determination of 87Sr/86Sr ratio by Mulitcollector ICP-MS. 18Oxygen was determined by Isotope Ratio Mass Spectrometry (IRMS). Results showed that all legislated elements (B, As, Pb, Zn, Cu and Cd) complied with maximum admissible values. Cd and Tl were removed from the statistical analysis since results were below the limit of quantification in all samples. Principal Component analysis (PCA) was applied to the remaining samples. This unsupervised method returned 5 principal components (PCs) that explained 82% of total variance. Twelve parameters (Li, B, Rb, K, 87Sr/86Sr, Cr, Ni, Cu, Pb, Fe, Sr, Mn) showed influence in the PCs and therefore were used for Hieraquical Cluster Analysis (HCA). Based on the results from HCA a predictive model using Linear Discriminant Analysis (LDA) was constructed. Samples were chosen either for building the LDA model or as cross validation data, according to the results obtained in the HCA. According to the obtained results it is possible to distinguish between Port and Douro wines based on elemental inorganic analysis and Sr isotope ratios. However, the choice of samples used for the construction of the predictive model is crucial for correct identification. Data was produced in compliance with quality requirements therefore being adequate to integrate Food Composition Databases.
- Recent developments and trends in the application of strontium and its isotopes in biological related fieldsPublication . Coelho, Inês; Castanheira, Isabel; Bordado, João Moura; Donard, Olivier; Silva, José Armando L.Strontium is a chemical element without biological functions in humans. In fact, only two biological roles are known, both as a biomineral constituent. However, strontium and calcium (a significant biometal) present chemical similarities; hence, the absorption of the former by living organisms is plausible. Based on the particular properties of isotopes of strontium several applications of this chemical element in biological sciences have been developed. These include its radioactive and non-radioactive isotopes in medical applications or resorting to its stable isotopes as analytical tools in isotope fingerprinting (87Sr/86Sr) to study dietary habits and migration patterns of ancient populations, food authentication and forensic sciences. This article, reviews papers published between 2012 and 2016, highlights the use of strontium isotope ratios for such biological related applications and compiles an analytical database, providing a valuable tool for future studies in the area.
- Tracing the geographical origin of food products with multielement fingerprinting and chemometrics: the case of Rocha pearPublication . Coelho, Inês; Matos, Ana S.; Teixeira, Rita; Nascimento, Ana; Bordado, João; Donard, Olivier; Castanheira, IsabelThe present work aims to develop a chemical fingerprint of Rocha pears produced within the PDO region based on multielement analysis.
- Tracing the geographical origin of PDO products with multielement fingerprinting and chemometrics: The case of Rocha pearPublication . Coelho, Inês; Matos, Ana; Teixieira, Rita; Nascimento, Ana; Bordado, João; Donard, Olivier; Castanheira, IsabelThis work aims at promoting the Protected Designation of Origin "Pera Rocha do Oeste" by providing a method to identify the geographical origin of this traditional Portuguese food commodity.