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- Acrylamide determination in Portuguese food matrices by UPLC-PDA and UPLC-MSPublication . André, Catarina; Delgado, Inês; Jesus, Susana; Castanheira, IsabelThe aim of this study was the determination of acrylamide in Portuguese food matrices thought the development and optimization of a chromatographic method with two different detectors. Acrylamide is classified by the International Agency for Research on Cancer (IARC) as a probable carcinogenic compound and the growing concern in human food is due to the fact that it was found in some foods when processed at high temperatures. Samples were bought randomly in local supermarkets and correspond to foods that suspect to contain high levels of this compound and contribute significantly to human consumption such as bolo do caco, fries, breakfast cereals, biscuits, coffee, coffee substitutes and pastel de nata. Sample preparation involved solid phase extraction. To quantify acrylamide were developed two chromatographic methods, UPLC-PDA and UPLC-MS/MS. The method who proved to be more suitable and quantify unequivocally acrylamide was UPLC-MS/MS. The chosen foodstuff for acrylamide determination presented a dissimilar range of values. Bolo do caco values depends on the cocking procedures. The lowest cooking temperature yield a lower acrylamide content (669 µg/Kg) while with the two samples cooked with the highest temperature the acrylamide content was must higher (1653 µg/Kg). In fries the content of acrylamide found was approximately 365 µg/Kg, while for breakfast cereals it varies between 238 and 187 µg/Kg depending on chocolate content. The content found was 58 µg/Kg for crackers and 203 µg/Kg for gingerbread. Coffee substitutes presented a value 5 times more than the coffee which was the lowest value determined with an acrylamide value of 25 µg/Kg. According to EFSA acrylamide values for pastry are between 75 and 1044 µg/Kg and the content of pastel de nata was 331 µg/Kg. The acrylamide content in all samples of Portuguese products analyzed were below the indicative values published by EFSA and are not considered to be main hazards of concern.
- Trace elements profile in nectars and fruit juices consumed in PortugalPublication . Coelho, Inês; Sardinha, Dina; Gueifão, Sandra; Castanheira, IsabelObjective: The main objectives of the present work were 1) to study the inorganic contaminants present in nectars and fruit juices consumed in Portugal and 2) to evaluate the reliability of pooled versus single samples to derive consistent estimates of exposure assessment to inorganic contaminants. Methodology: Twenty four samples of juices and nectars representative of the domestic market were acquired in May 2014 in the Lisbon region. Samples of representative brands were collected randomly in supermarkets of national implementation in accordance with consumer preference. Afterwards these were analyzed both as single units and as two pools, one of nectars and the other of juices, composed by 12 samples each. The work focused on the determination of Copper, Manganese, Cobalt, Selenium, Zinc, Arsenic, Cadmium, Chromium and Lead using ICP-MS. Element determination was preceded by high pressure closed vessel microwave digestion. Speciation studies for the determination of inorganic arsenic were carried out through HPLC-ICP-MS. Results: Cadmium was present in concentrations above the limit of quantification (LQ) only in one sample. Arsenic was found above the LQ (LQ=2 µg/L) in almost half the samples under study. The speciation study proved that most of this arsenic is present in the inorganic forms (As III and As V). However, there is no European legislation for arsenic in fruit juice. Inconsistent results were obtained for arsenic between pooled and single samples. Conclusions: In the nectars and fruit juices studied metals and metalloids of known toxicity were found in levels below legislated limits for water intended for human consumption. In light of the obtained results arsenic speciation is crucial to clarify the toxicity of arsenic present in foodstuffs. Also, the present work provided a clear example of how, due to a dilution factor, pooling might mask the presence of a contaminant and therefore underestimate exposure assessments.