Abstract
Olive (Olea europaea L.) represents one of the most important and ancient crops in the Mediterranean countries, being widely known due to the optimal organoleptic characteristics of its oil, besides the important health benefits assigned to this product in the last few years. Since olive oil composition, respecting specific trace elements, has a direct impact on the quality and safety of this product, eleven monovarietal and twelve commercial olive oils were analysed spectrometrically concerning their metal composition. Regarding quality parameters, the monovarietal olive oils display larger quantities of Mg, Fe, Mn, while the commercial samples are characterized by greater amounts of Na, Ca, Cu and Zn. In which respects to safety parameters, the commercial samples present higher values for Al and Pb, and lower quantities of Cd, respecting the monovarietal ones. The assessment of the values observed for the trace elements, resorting to multivariate statistical methods, allowed to clearly distinguish the type of olive oil production monovarietal or commercial blend. For this purpose, besides Cluster analysis, the data have been subjected to Principal Component Analysis undertaken for either all the evaluated parameters simultaneously, or the quality/safety parameters separately, both data sets allowing the discrimination of the samples.

Abstract
The conformational preferences and hydrogen-bonding motifs of several potential chemopreventive hydroxycinnamic derivatives were determined by inelastic neutron scattering spectroscopy. The aim is to understand their recognized beneficial activity and establish reliable structure-activity relationships for these types of dietary phytochemicals. A series of phenolic acids with different hydroxyl/methoxyl ring substitution patterns were studied: trans-cinnamic, p-coumaric, m-coumaric, trans-caffeic and ferulic acids. Their INS spectra were completely assigned by theoretical calculations performed at the Density Functional Theory level, for the isolated molecule, dimeric centrosymmetric species and the solid (using plane-wave expansion approaches). Access to the low energy vibrational region of the spectra enabled the identification of particular modes associated with intermolecular hydrogen-bonding interactions, which are the determinants of the main conformational preferences and antioxidant capacity of these systems.

Abstract
The interaction between gold sub-nanometer clusters composed of ten atoms (Au10) and tetrakis(4-sulfonatophenyl)porphyrin (TPPS) was investigated through various spectroscopic techniques. Under mild acidic conditions, the formation, in aqueous solutions, of nanohybrid assemblies of porphyrin J-aggregates and Au10 cluster nanoparticles was observed. This supramolecular system tends to spontaneously cover glass substrates with a co-deposit of gold nanoclusters and porphyrin nanoaggregates, which exhibit circular dichroism (CD) spectra reflecting the enantiomorphism of histidine used as capping and reducing agent. The morphology of nanohybrid assemblies onto a glass surface was revealed by atomic force microscopy (AFM), and showed the concomitant presence of gold nanoparticles with an average size of 130 nm and porphyrin J-aggregates with lengths spanning from 100 to 1000 nm. Surface-enhanced Raman scattering (SERS) was observed for the nanohybrid assemblies.

Abstract

Abstract
n-Alkanes and long-chain alcohols (LCOH) have been used as faecal markers to assess the feeding behaviour of both wild and domestic herbivore species. However, their chemical analysis is time-consuming and expensive, making it necessary to develop more expeditious methodologies to evaluate concentrations of these markers. This work aimed to evaluate the use of Fourier Transform Infrared Spectroscopy (FTIR) technology in the near infrared (NIR) and mid infrared (MIR) intervals, for the determination of n-alkane and LCOH concentrations of different plant species and faecal samples of domestic herbivores. Spectra of 33 feed samples, namely L. perenne, T. repens, U. gallii, short heathers (mixture of Erica spp. and Calluna vulgaris), improved pasture grasses (mixture of L. perenne and A. capillaris), heath grasses (mixture of P. longifolium and A. curtissii), improved pasture species (mixture of L. perenne, T. repens and A. capillaris) and herbaceous species (mixture of all herbaceous species found in the plot)) and 181 faecal samples (cattle and horses) were recorded. In order to develop calibrations for the prediction of n-alkanes and LCOH concentrations, partial least squares (PLS) regression was used. Regarding the models developed for plant species, the best results were observed for the calibrations using NIR. The best external validation coefficients of determination (R(2)v) obtained were 0.90 and 0.79 for LCOH and n-alkanes, respectively. For faecal samples, in the NIR interval, results indicate similar external validation predictions (R(2)v) for both animal species (0.64). On the contrary, in the MIR interval, differences between cattle (0.70) and horses (0.57) faecal samples in R(2)v were observed. Regarding the models created for both animal species faeces, LCOH (C-26-OH and C-30-OH concentrations ranging from 713.3 to 4451.9 mg/kg DM, respectively; R(2)v values ranging from 0.72 to 0.95) and n-alkanes (C31 and C33 concentrations ranging from 112.8 to 643.2 mg/kg DM, respectively; R(2)v values ranging from 0.19 to 0.90) present in higher concentrations tended to be those with better estimates. Results obtained suggest that the selection of the technique to be used may depend on the type of matrix, being the homogeneity of the matrices one of the most important factors for its success. In order to improve the accuracy and robustness of the models created for the estimation of the concentrations of these markers using these methodologies, the database (greater variability) used for the calibrations of these models must be increased.

Abstract
Kaolin-particle film has been considered a low-cost technology to mitigate the adverse effects of high light and temperature, and drought in several crops. However, the underlying excess energy absorption and dissipation mechanisms, and related components associated with kaolin photoprotective effects in grapevines are poorly explored. This study aims to understand the interactions between kaolin foliar treatment and photosynthetic pigments accumulation, carotenoids metabolism, xanthophyll cycle regulation, and its putative role on the non photochemical quenching (NPQ) processes in Touriga-Franca (TF) and Touriga-Nacional (TN) varieties. The experiments were conducted during the 2017 summer season in a commercial vineyard, and measurements were performed at pre-dawn and midday in each sampling date (EL35 - veraison; EL38 - full mature). Overall, TF variety showed higher accumulation of chlorophylls, xanthophylls, and de-epoxidation state (DPS) than TN. Kaolin treatment enhanced TN chlorophyll accumulation up to 114 % at EL35 (veraison) and 123 % at EL38 (full mature), highlighting its protective role on chlorophyll degradation, while no changes were found in TF, which might indicate a lower need for particle-film technology in this variety under the current environmental conditions. Individual carotenoids were mainly higher in the treated leaves of both varieties, as well as the xanthophyll cycle pigments zeaxanthin (Z(x)) and violaxanthin (V-x). Simultaneously, the DPS and NPQ values were lower in TN and TF treated leaves (1.92 - 2.36) compared to untreated vines (3.19 - 3.24), suggesting that there might be other components influencing NPQ levels beyond Z(x), with an indirect role in long-lasting NPQ processes. In addition, in the TF kaolin-treated leaves, violaxanthin de-epoxidase (VvVDE1) and zeaxanthin epoxidase (VvZEP1) gene expression were respectively 3-fold and 4-fold upregulated at stage EL35, while VvZEP1 gene expression decreased at stage EL38 in TN kaolin-treated leaves, indicating an optimised regulation of the xanthophyll cycle. These findings suggest that kaolin treatment promoted a fine-tuning of grapevine summer stress responses under sustained summer stress factors, by managing xanthophyll cycle dynamics, and pigments accumulation.