110 research outputs found

    Application of the FTIR technique as a non‐invasive tool to discriminate Portuguese olive oils with protected designation of origin

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    Three Portuguese olive oils with PDO (‘Azeite do Alentejo Interior’, ‘Azeites da Beira Interior’ and ‘Azeite de Trás-os-Montes’) were studied considering their physicochemical quality, antioxidant capacity, oxidative stability, total phenols content, gustatory sensory sensations and Fourier transform infrared (FTIR) spectra. All oils fulfilled the legal thresholds of EVOOs and the PDO's specifications. Olive oils from ‘Azeite da Beira Interior’ and ‘Azeite de Trás-os-Montes’ showed greater total phenols contents and antioxidant capacities, while ‘Azeites da Beira Interior′ presented higher oxidative stabilities. Linear discriminant models were developed using FTIR spectra (transmittance and the 1st and 2nd derivatives), allowing the correct identification of the oils’ PDO (100 % sensitivity and specificity, repeated K-fold-CV). This study also revealed that multiple linear regression models, based on FTIR transmittance data, could predict the sweet, bitter, and pungent intensities of the PDO oils (R2≥0.979±0.016; RMSE≤0.26±0.05, repeated K-fold-CV). This demonstrates the potential of using FTIR as a non-destructive technique for authenticating oils with PDO.The authors are grateful to the Foundation for Science and Technology (FCT, Portugal) for financial support by national funds FCT/MCTES (PIDDAC) to CIMO (UIDB/00690/2020 and UIDP/00690/2020) and to the Associate Laboratory SusTEC (LA/ P/0007/2020). The authors are also grateful to the “Project OLIVE4ALL – Olive Heritage for Sustainable Development: Raising Community Awareness of Living Heritage” (ref. JPICH/ 0001/2020), financed by FCT (Portugal). Nuno Rodrigues thanks the FCT – Foundation for Science and Technology, P.I., for the National funding through the institutional program contract for scientific employment. Sandra Lamas also acknowledges the Ph.D. research grant (2022.10070.BD) provided by FCT.info:eu-repo/semantics/publishedVersio

    Widespread hybridization between Invasive bleak (Alburnus alburnus) and Iberian chub (Squalius spp.): A neglected conservation threat

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    Hybridization between native and nonnative fish species is a major conservation issue, especially in ecosystems with high levels of endemism, such as Iberian streams. To date, hybridization with the invasive bleak Alburnus alburnus has been reported for the Iberian chub Squalius alburnoides and S. pyrenaicus and in scattered locations only. However, the bleak is spreading in the region, potentially increasing the risks of hybridization with other Squalius species. To gather a more comprehensive picture on the current geography of hybridization, we compiled records on hybrids between bleak and chub in Portugal and conducted genetical assessments of hybrids between bleak and S. carolitertii. We found that hybridization with bleak is widespread throughout Portuguese river basins and involves at least S. alburnoides, S. pyrenaicus and S. carolitertii. Hybridization with bleak may not only cause waste of reproductive effort and damage the genetic integrity of these endemic species but also promote shifts in the reproductive dynamics of the S. alburnoides hybrid complex, which includes individuals with various ploidy levels and combinations of parental genomes, reproducing sexually and asexually. We recommend that future studies characterize the fitness of bleak hybrids and their ecological and genetic interactions with native fish, in order to design effective conservation measures

    Reproduction of the blue jack mackerel, Trachurus picturatus, in western Portugal: microscopic gonad analysis reveals indeterminate fecundity and skipped spawning patterns

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    Blue jack mackerel, Trachurus picturatus, is the fifth most landed fish species in mainland Portugal, but information on its reproductive biology is scarce. From September 2018 to August 2019, 626 specimens were collected from commercial vessels to clarify the reproductive strategy of the T. picturatus population off the west coast of Portugal. The proportion and length range of males and females were similar. Only three of the specimens collected were categorized as immature, indicating that the fish caught in the fishery are primarily mature. The spawning season lasted from late January until the end of March, with gonadosomatic indices being similar for males and females. Fecundity was indeterminate, and estimated batch fecundity ranged between 6,798 (at 25.4 cm TL) and 302,358 oocytes (at 33.8 cm TL). The low number of females showing direct evidence of imminent or recent spawning suggests a low number of spawning events. In addition, 12.7% of females were considered non-reproductive due to ovary abnormalities including parasitic infection by Kudoa species, atretic structures and skipped spawning events. This study highlights the importance of accounting for skipped spawning events and ovary abnormalities in the management of species fisheries.info:eu-repo/semantics/publishedVersio

    Generation of vortices and observation of Quantum Turbulence in an oscillating Bose-Einstein Condensate

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    We report on the experimental observation of vortex formation and production of tangled vortex distribution in an atomic BEC of Rb-87 atoms submitted to an external oscillatory perturbation. The oscillatory perturbations start by exciting quadrupolar and scissors modes of the condensate. Then regular vortices are observed finally evolving to a vortex tangle configuration. The vortex tangle is a signature of the presence of a turbulent regime in the cloud. We also show that this turbulent cloud has suppression of the aspect ratio inversion typically observed in quantum degenerate bosonic gases during free expansion.Comment: to appear in JLTP - QFS 200

    Integrative analysis based on HPLC-DAD-MS/MS and NMR of Bertholletia excelsa Bark Biomass Residues: Determination of ellagic acid derivatives

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    Bertholletia excelsa Bonpl. (Lecythidaceae) is a South American tree worldwide known for providing the Brazil nuts. In the Amazon Region, B. excelsa is found in monocultures, integrating agroforestries and providing raw materials for food and timber industries. Through the application of an integrative analysis based on high-performance liquid chromatography coupled with diode array detector and tandem mass spectrometry (HPLC-DAD-MS/MS) and nuclear magnetic resonance (NMR) techniques, the present study showed that B. excelsa bark biomass residues contain large quantities of ellagic acid (EA) and its derivatives. Qualitatively, five compounds were characterized for the first time in this species. Quantitations were carried out to determine the total amount of these compounds in outer and inner bark tissues. A total of 4.96 and 44.09 g of EA derivatives per kg of dry residues was determined for the outer and inner barks, respectively. Among the EA derivatives, eschweilenol C, ellagic acid and valoneic acid dilactone were the main compounds. These results pointed B. excelsa barks as a valuable biomass residue with potential to be source of health-promoting compounds. Therefore, a potential raw material as source of valuable bioactive phenolic compounds is described herein. © 2019 Sociedade Brasileira de Química
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