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- Effect of freeze drying, hot air drying, and hot air drying preceded by freezing on phytochemical composition, antioxidant activity, and technological properties of mango peelsPublication . Marçal, Sara; Vilas-Boas, Ana A.; Campos, Débora A.; Pintado, ManuelaThis study evaluated the impact of freeze drying (FD), hot air-drying (65 ºC; 48 h) (HAD), and HAD preceded by freezing (-20 ºC; 30 days) (FZ+HAD) on mango peels’ composition, antioxidant activity, and technological properties. Overall, drying had no marked effect on macronutrients and fiber composition. FD (-9%), HAD (-55%), and FZ+HAD (-72%) reduced vitamin C. FD preserved all free phenolics, while HAD (-20 – -42%) and FZ+HAD (-17 – -71%) decreased most of them. HAD, FZ+HAD, and FD reduced 2, 6, and 9 of the 10 bound phenolics identified. FZ+HAD performed worst in preserving b-carotene, lutein, and violaxanthin. All drying methods impaired bound phenolics’ antioxidant activity. FZ+HAD was the darker powder. FD showed the best and worst oil and water absorption capacities. This study evaluated the impact of drying on mango peels’ bound phenolics and compared HAD with FZ+HAD for the first time. FZ+HAD was inadequate regarding antioxidants preservation.
- Traditional vs microwave-assisted hydrodistillation of Rosmarinus officinalis L. essential oil: a response surface optimization approachPublication . Pedrosa, Mariana C.; Amaral, Joana S.; Heleno, Sandrina; Pintado, Manuela; Barros, Lilian; Carocho, MárioEssential oils (EOs) from rosemary (Rosmarinus officinalis L.) were optimized as natural preservatives using hydrodistillation (HD) and microwave-assisted hydrodistillation (MAHD) with response surface methodology and multi-response desirability analysis.For HD, a Box–Behnken design assessed soaking time, particle size, solid/liquid ratio, and extraction time. MAHD optimization used a two-stage approach: fractional factorial screening followed by a central composite design focusing on solid/liquid ratio and extraction time. Responses included EO yield and volatile compound content (VCI).Both quadratic (HD) and two-factor interaction (MAHD) models showed strong fit (R² up to 0.95) with no significant lack of fit. HD produced higher yields and VCI at longer extraction times, while MAHD achieved faster extraction with slightly lower yields but improved consistency in oxygenated monoterpenes. GC–MS confirmed a chemotype dominated by 1,8-cineole, camphor, borneol, α-terpineol, and α-pinene.
- Comparative evaluation of machine learning and deep learning strategies for Port wine authentication and age prediction by FT-IR Spectroscopy and chemometric ModellingPublication . Ferreira, V. S. Fernandes; Ferreira, A. C. SilvaPort wine authentication and age validation have significant reputational and economic implications. However, their analytical assessment remains a major challenge, as it is still based mainly on sensory analysis and complementary metadata from chemical profiling, ranging from molecular markers to, more recently, radiocarbon-IMS (C¹⁴) measurements. Nevertheless, no standard practice is currently prescribed by regulatory authorities. This study presents a spectroscopic modelling framework for Port wine age prediction, supported by a systematic chemometric evaluation of sixteen machine learning (ML) and deep learning (DL) approaches applied to mid-infrared Fourier Transform Infrared (FT-IR) spectral data. Tabular data still lacks a one-fits-all model regarding DL architectures. A dataset of 7,281 FT-IR spectra covering four Port wine categories - “Colheita”, “Tawny”, Late Bottled Vintage (LBV), and “Vintage”- was preprocessed using Standard Normal Variate (SNV) transformation and mean centering applied exclusively from training partitions to prevent information leakage; Venetian Blind cross-validation was implemented to account for sequential autocorrelation inherent in spectroscopic datasets. Sixteen modelling strategies were benchmarked, spanning classical chemometrics (PLS, LDA, SVM, regularized regression, Random Forest, Gradient Boosting) and deep learning architectures (1D CNNs, Multi-scale CNNs with Inception-style parallel branches, residual MLP, and Deep Ensembles). CNNs with Inception-style parallel branches, residual MLP combined with Deep Ensembles were selected due to its ability of offering some interpretability, breaking the “Black-box” concept regarding DL models. For wine type classification, Support Vector Machine with an RBF kernel achieved the highest accuracy (95.88%, ROC-AUC 0.9945), with Random Forest providing comparable performance (93.54%, ROC-AUC 0.9936) alongside explicit featureimportance maps identifying discriminative spectral regions. For age regression, a Deep Ensemble of five residual MLP models attained R² = 0.9803 (MAE = 1.25 years), substantially outperforming the best traditional chemometric method, Gradient Boosting (R² = 0.8401, MAE = 2.94 years). A novel Hybrid Two-Stage Random Forest pipeline - combining wine-type classification with type-specific age regressors - achieved R² = 0.9630 (MAE = 1.28 years) without GPU requirements. A leverage- based individual confidence interval method provided well-calibrated prediction uncertainty with 97.7% empirical coverage. Chemical interpretability was confirmed by convergence of feature importance patterns across methods with established wine ageing biochemistry, validating that models capture genuine chemical variation. The structure of the data strongly influences the choice of modelling architecture: while deep learning has demonstrated outstanding performance for image and natural language tasks, spectroscopic tabular data still lacks universally accepted one-size-fits- all architecture, leaving the optimal model design context-dependent on dataset size, interpretability requirements, and available computational resources.
- Seasonal hotspots and offshore accumulation of phycotoxins in a subtropical semi-enclosed bay: insights from Qinzhou Bay, Beibu GulfPublication . Geng, Hui-Xia; Lin, Zhuo-Ru; Tang, Wen-Jiao; Cunha, Sara A.; Kang, Zhen-Jun; Han, Xiao-Tian; Wang, Jin-Xiu; Yu, Ren-ChengPhycotoxins produced by harmful algae pose increasing risks to coastal ecosystems and aquaculture activities, yet their dynamics in subtropical semi-enclosed bays remain poorly understood. In this study, the spatiotemporal distribution, composition, and potential sources of phytoplankton-associated phycotoxins in Qinzhou Bay (South China Sea) were investigated based on monthly surveys from November 2021 to November 2022. Both paralytic shellfish toxins (PSTs) and lipophilic marine toxins (LMTs) were widely detected, with GTX analogues, pectenotoxin-2 (PTX2), and homo-yessotoxin (hYTX) as dominant components. Toxin occurrence showed pronounced seasonality, with higher prevalence in May and June. Spatially, elevated toxin levels were consistently observed in open waters outside the bay, suggesting that hydrodynamic conditions favor the accumulation of toxigenic phytoplankton. Combined morphological and molecular analyses identified Alexandrium spp. and Gymnodinium sp. as key PST producers, whereas Dinophysis and Protoceratium reticulatum, Gonyaulax spinifera, and Lingulodinium polyedra were identified as potential sources of LMTs. The decoupling between toxin occurrence and cell abundance highlights the importance of improving sampling strategies and identification methods for toxigenic dinoflagellates. These results reveal distinct seasonal windows and offshore hotspots of phycotoxin occurrence and provide a critical baseline for future monitoring and risk management in aquaculture-dominated coastal systems.
- Rsm-mediated post-translational control of the pseudomonas putida Type VI1 secretion systemPublication . Civantos, Cristina; Paredes, Carmen; Murillo-Torres, Marina; Botelho, João; Sánchez-Romero, María Antonia; Allsopp, Luke P.; Bernal, PatriciaThe Type VI secretion system (T6SS) is a bacterial nanoweapon that injects toxic effectors into prokaryotic and eukaryotic cells. It is widely found among gram-negative bacteria and provides a significant fitness advantage in interbacterial competition. Pseudomonas putida KT2440 possesses three T6SS clusters (K1-, K2- and K3-T6SS) that combat phytopathogens. This makes this strain a potent biocontrol agent that protects plants from pathogens and can be further enhanced by a better understanding of its T6SS regulation. Although the core components of T6SS are conserved, the elements controlling its regulation differ among bacterial species. T6SS activity is regulated by various factors acting at different levels, from transcription to post-translational modification, to ensure precise control of its activity. Here, we demonstrate the critical importance that the three Rsm proteins, RsmIEA, have in controlling the K1-T6SS structural components and related orphan elements at the post-transcriptional level in Pseudomonas putida. We identified multiple Rsm-binding sites responsible for directly repressing the translation of T6SS proteins (Hcp1 and Hcp5) and their associated effectors (Tke2 and Tke7). Derepression of K1-T6SS mRNA in the rsmIEA mutant led to enhanced translation and expression of the K1-T6SS components and effectors, and critically increased the number of cells in the population with assembled T6SS. This results in a greater capacity to secrete toxins and kill prey cells via the T6SS-dependent mechanism. Finally, we demonstrate the K1-T6SS ability to kill environmental pathogens, including Salmonella enterica and Erwinia amylovora.
- Metabarcoding of mediterranean monk seal (Monachus monachus) scats from the isolated population of Madeira reveals a diverse piscivorous dietPublication . Vijayakumar, Subramaniam; McIvor, Ashlie; Themudo, Goncalo Espregueira; Pires, Rosa; Thomsen, Philip Francis; Dinis, Ana; Canning-Clode, João; Carneiro, João; Campos, Paula F.The Mediterranean monk seal (Monachus monachus) is one of the world’s most endangered marine mammals, and information on its feeding ecology is needed to support conservation planning. Here, high-throughput DNA metabarcoding of scat samples from Madeira was used to characterise the diet of this geographically isolated population. Fourteen samples were analysed using universal fish primers targeting the mitochondrial 12S rRNA gene, enabling detection of both bony and cartilaginous fishes. Across samples, 38 prey taxa were identified, including records not previously reported in monk seal diet studies, such as Fistularia petimba, as well as cartilaginous fish such as Bathytoshia centroura, Dasyatis pastinaca, and Torpedo marmorata. Frequency of occurrence indicated a diet dominated by demersal and reef-associated taxa, with frequent detection of Sparidae, alongside evidence of opportunistic prey use. Overall, these results provide a high-resolution dietary profile for monk seals in Madeira and demonstrate the utility of scat metabarcoding for monitoring trophic ecology in small, threatened populations. This approach offers a scalable framework for assessing dietary shifts over time and informing adaptive management in human-impacted coastal ecosystems.
- Fire-resistant bio-based polyurethane foams designed with two by-products derived from sugarcane fermentation processPublication . Capeto, Ana Paula; Amorim, Manuela; Sousa, Sérgio; Costa, Joana R.; Uribe, Braian; Guimarães, Ana Sofia; Pintado, Manuela; Oliveira, Ana L. S.There is a great interest in replacing conventional fossil-based polymers and composites with inorganic or organic waste-based materials and filler-type additives, to promote environmental sustainability and circularity. The main objective of this study was the design of water-blown polyurethane rigid foams integrating two by-products derived from the Amyris fermentation process of production of β-farnesene. The distillation residue (FDR) was used as main polyol component in the neat formulation of the foams (PF) that it was supplemented (PFA) with 4.5% of sugarcane bagasse ash (SCBA) added as a filler with fire-retardant properties. The impact of both by-products on the foam density and morphology, and in the thermal, mechanical, and flame-retardant properties was assessed. SCBA presence led to a reduction in apparent density, cells size, and glass transition, delaying the thermal decomposition. The differences observed in the thermal conductivity and flammability test parameters suggest a visible impact of the ash incorporation, thus meeting the fire protection standard UL 94, class HB. Highlighting the need for further optimization, this work presents a practical example of the integration of different wastes derived from the same fermentation process in the formulation of sustainable PUR foams with reduced flammability.
- Green chitosan: thiourea dioxide cleaning gel for manganese stains on granite and glass substratesPublication . Campos, Bruno; Marco, Alexandra; Cadeco, Guihermina; Freire-Lista, David M.; Silvestre-Albero, Joaquin; Algarra, Manuel; Vieira, Eduarda; Pintado, Manuela; Moreira, PatríciaThe cleaning or removal of manganese stains on Cultural Heritage has not been much tested or successful so far. The aim of this article was to assess a new green cleaning gel for Mn-rich black-blue stains on different substrates. The black-blue stains were characterized at optical and chemical level through RGB data, colorimetry, optical microscope, FTIR, XRF and XPS. Mn-stained granite found on historical churches at Vila Real (North of Portugal) and glass jars of Leclanché cells, belonging to the ISEP’s Museum (Portugal) collection, were the ideal case studies to test the efficiency of Chitosan:Thiourea Dioxide (TD) cleaning gel. TD proved to be the best candidate to reduce insoluble manganese oxides, over Hydroxylamine Hydrochloride and Hydroxymethanesulfinic Acid. Cleaning assays performed on stained granite samples collected at a historical quarry and in situ application on stained granite churches showed the complete removal of the stains. Similar results were obtained on stained glass jars. This article presents an innovative, feasible and green Chitosan gel embedded with TD and phosphoric acid, applied to the cleaning of Mn-stained granite and glass substrates.
- Evaluation of the fungicide treatment with copper oxide and potassium phosphonate solutions for the sustainable management of P. pinaster trees infected with B. xylophilusPublication . López-Villamor, Adrián; Silva, Marta Nunes da; Vasconcelos, MartaFungicides induce changes in the plants promising to increase tolerance of Pinus pinaster against the pathogenic pinewood nematode (PWN). To test this hypothesis, P. pinaster plants were inoculated with the PWN, treated with copper oxide (CO) or potassium phosphonate (PP), and evaluated post-inoculation for: i) the extent of foliar symptoms; ii) nematode density inside stem tissues; iii) proxies for oxidative damage and antioxidant activity, iv) mineral concentration; and v) bacterial diversity. The mortality of infected plants reached 12.5% regardless of the treatment, but plants treated with fungicides, particularly with PP, had significantly lower PWN density (up to 0.61-fold). Plants treated with PP had substantially higher concentrations of anthocyanins at 14 dai than those treated with CO and non-Treated plants (by 1.47-fold), possibly contributing to the lower PWN colonization and degree of foliar symptoms observed. CO and PP led to increased lipid peroxidation at 28 dai (by 1.84- and 1.77-fold), and PP showed higher flavonoids concentration than CO (by 1.37- and 0.49-fold), corroborating its higher potential in increasing plant antioxidative response during infection. Fungicides also induced significant changes in micronutrient accumulation in plant tissues, resulting in a decrease in Zn and P concentrations in plants treated with either fungicide as compared to infected nontreated plants. Finally, CO treatment increased the diversity of the bacterial communities, while PP decreased microbial biodiversity. Altogether, results suggest that treatment with CO and PP increases tolerance against B. xylophilus by promoting the plant antioxidant system, changing the accumulation of essential minerals, and modulating plant-associated bacterial diversity.
- Skincare potential of a sustainable postbiotic extract produced through sugarcane straw fermentation by Saccharomyces cerevisiaePublication . Duarte, Marco; Carvalho, Maria João; Carvalho, Nelson Mota; Silva, João Azevedo; Mendes, Adélia; Ribeiro, Inês Pinto; Fernandes, João Carlos; Oliveira, Ana Lúcia; Oliveira, Carla; Pintado, Manuela; Amaro, Ana; Madureira, Ana RaquelPostbiotics, a new class of molecules derived from microorganism’s metabolism, are defined as a “preparation of inanimate microorganisms and/or their components that confers a health benefit on the host”. They can be produced by fermentation, using culture media with glucose as the carbon source, and lactic acid bacteria of the genus Lactobacillus, and/or yeast, mainly Saccharomyces cerevisiae as fermentative microorganisms. Postbiotics comprise different metabolites, and have important biological properties (antioxidant, anti-inflammatory, etc), which is why their use in cosmetics should be considered. During this work, the production of postbiotics was carried out by fermentation with sugarcane straw, as a source of carbon and other active compounds, and as a more sustainable and promising process to obtain more bioactive extracts at the end. For this, its saccharification process was carried out with cellulase at 55 ºC for 24 h. Fermentation was performed sequentially after saccharification at 30 ºC, for 72h, using S. cerevisiae. The cells-free extract was characterized regarding its composition, antioxidant activity, and skincare potential. Its use was safe at concentrations below ~ 20 mg.mL − 1 for keratinocytes and ~ 7.5 mg.mL − 1 for fibroblasts. It showed antioxidant activity, with ABTS IC50 of 1.88 mg.mL − 1 , and inhibited elastase and tyrosinase activities by 83.4% and 42.4%, respectively, at the maximum concentration tested (20 mg.mL − 1 ). In addition, it promoted the production of cytokeratin 14, and demonstrated anti-inflammatory activity at a concentration of 10 mg.mL − 1 . Finally, in the skin microbiota of human volunteers, the extract inhibited the Cutibacterium acnes bacterium and the Malassezia fungal genus. In short, postbiotics were successfully produced using straw as substrate, and as source of carbon and phenolic compounds. These postbiotics showed bioactive properties that potentiate their use in the development of cosmetic and skincare products, such as the treatment of acne or other skin diseases, due to their anti-inflammatory and inhibitory effect on the bacteria responsible for acne, as well as on potentially colonizing fungi.
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