Distribution of lipid compounds in sediments from Conceição Lagoon, Santa Catarina Island, Brazil

Lipid compounds from five sediment-water interface samples and a sediment core with 75 cm depth were used to assess sources of organic matter in Conceição Lagoon, located on Santa Catarina Island. The results which were based on the molar C:N:P ratios, relative abundance of sterols (dominated by the C27 sterols), n-alkanols (0.2-1.2 µg g-1), n-alkanes (0.4-5.0 µg g-1) and the Carbon Preference Index (CPI), indicated that the organic matter is predominantly of terrestrial origin (C/N > 10 and CPI > 2). Total phosphorus (TP, average 5.20 µmol g-1) and organic carbon (TOC, average 2.90 mmol g-1) contents were well correlated with the silt and clay fractions at all locations. In the sediment core, chronologically dated with the radionuclide 210Pb, the depth interval from 55 to 75 cm was dominated by the sand fraction (> 50%). However, parameters such as TOC, TP and n-alkane contents increased considerably at this depth suggesting a change in organic matter input sources

Chemical characterization and antioxidant proprieties of Myrciaria jaboticaba bioresidues

Jabuticaba (Myrciaria jaboticaba (Vall.) O. Berg) is a Brazilian berry very appreciated for in natura consumption. However, its epicarp is not normally consumed, and in manufacture of products from jabuticaba fruit, it is responsible for the generation of large amounts of residues [1,2]. The exploration of by-products is becoming important for the obtainment of valuable bioactive compounds for food and pharmaceutical industries [2]. In this context, the present work aimed in the characterization of the main bioactive compounds present in jabuticaba epicarps and its potential antioxidant.Foundation for Science and Technology (FCT, Portugal) for financial support by national funds FCT/MCTES to CIMO (UIDB/00690/2020); national funding by FCT, P.I., through the institutional scientific employment program-contract for M.I. Dias, L. Barros, and C. Pereira contract; and B. Albuquerque (SFRH/BD/136370/2018) PhD grant; ERDF through the Regional Operational Program North 2020, within the scope of Project NORTE-01-0145-FEDER-023289: DeCodE and project Mobilizador Norte-01-0247-FEDER-024479: ValorNatural®; FEDER-Interreg España-Portugal programme for financial support through the project 0377_Iberphenol_6_E.info:eu-repo/semantics/publishedVersio

Influence of air-drying temperature on the quality and bioactive characteristics of dried galega kale (Brassica Oleracea L. Var. Acephala

Drying processes are often applied to preserve and increase the shelf life of vegetables. These products contain an extensive collection of phytochemicals known to provide health benefits. However, these compounds generally undergo significant degradation during drying because of their sensitivity to heat, light, oxygen, as well as to leaching phenomena. Thus, increased attention has been given to the concerns regarding the quality degradation of vegetables during drying. Galega kale was selected, since this leafy vegetable, often included as soups ingredient, presents high amounts of vitamins and micronutrients. The objective of this work was to evaluate the drying characteristics and the effect of drying temperature on quality characteristics of Galega kale, without any pretreatment. Drying times of 330, 162, 78 and 51 min provided minimal moisture contents, using temperatures of 35, 50, 70 and 85 ⁰C, respectively. Increasing air-drying temperatures originated significant changes in color and nutritional parameters. The L* and a* values diminished, and b* increased, originating increasing values of chroma, total colour difference and browning index, as well as decreasing values of hue angle. A pronounced effect on the retention of total phenolic compounds was observed. Regarding antioxidant capacity and vitamin C, losses of 51.7±7.5- 69.6±3.7 and 4.8±9.7-55.5±7.4% were obtained, respectively. Chlorophyll a content decreased with increasing drying temperatures, with losses between 8.9±6.7 and 35±5.6%, while degradation of chlorophyll b was negligible. In conclusion, the air-drying of Galega kale without any pretreatment resulted in considerable deterioration of its quality characteristics and nutritional value

Mathematical modelling of convective drying of Galega kale

info:eu-repo/semantics/publishedVersio

Fast decellularization process using supercritical carbon dioxide for trabecular bone

Decellularization is a process that consists on the removal of immunogenic cellular material from a tissue, so that it can be safely implanted as a functional and bioactive scaffold. Most decellularization protocols rely on the use of harsh chemicals and very long washing processes, leading to severe changes in the ultrastructure and loss of mechanical integrity. To tackle these challenges, supercritical carbon dioxide (scCO2) is herein proposed as an alternative methodology for assisting decellularization of porcine trabecular bone tissue and is combined, for the first time, with Tri(n-butyl) phosphate (TnBP). Histological and DNA analysis revealed that both TnBP and scCO2 were able to extract the DNA content from the scaffolds, being this effect more pronounced in treatments that used TnBP as a co-solvent. The combined protocol led to a decrease in DNA content by at least 90%, demon- strating the potential of this methodology and opening new possibilities for future optimizations.info:eu-repo/semantics/publishedVersio

Structural Insights into Dissimilatory Sulfite Reductases: Structure of Desulforubidin from Desulfomicrobium Norvegicum

Dissimilatory sulfite reductases (dSiRs) are crucial enzymes in bacterial sulfur-based energy metabolism, which are likely to have been present in some of the earliest life forms on Earth. Several classes of dSiRs have been proposed on the basis of different biochemical and spectroscopic properties, but it is not clear whether this corresponds to actual physiological or structural differences. Here, we describe the first structure of a dSiR from the desulforubidin class isolated from Desulfomicrobium norvegicum. The desulforubidin (Drub) structure is assembled as α2β2γ2, in which two DsrC proteins are bound to the core [DsrA]2[DsrB]2 unit, as reported for the desulfoviridin (Dvir) structure from Desulfovibrio vulgaris. Unlike Dvir, four sirohemes and eight [4Fe–4S] clusters are present in Drub. However, the structure indicates that only two of the Drub coupled siroheme-[4Fe–4S] cofactors are catalytically active. Mass spectrometry studies of purified Drub and Dvir show that both proteins present different oligomeric complex forms that bind two, one, or no DsrC proteins, providing an explanation for conflicting spectroscopic and biochemical results in the literature, and further indicating that DsrC is not a subunit of dSiR, but rather a protein with which it interacts

Evaluation of drying and storage conditions on nutritional and sensory properties of dried galega kale (Brassica oleracea L. var. Acephala)

This work evaluated the effect of the air-drying temperature and vacuum packaging on quality and nutritional compounds of dehydrated galega kale, previously steam blanched, during 5 months of storage. When compared with the vacuum packaged kale, the packaging without vacuum yielded improved nutritional features, in general. This approach combined with a drying temperature of 40°C resulted in retention percentages of 62, 38, 92, and 48% for vitamin C, total phenolic content, total antioxidant capacity, and chlorophylls, respectively. The acceptance of the dried product by the consumer was assessed through a focus group. The participants classified the product as a practical and convenient alternative to cook healthier dishes. The appearance of dried galega kale was described as being fragile and being with nice smell, natural colour, and flavour similar to the fresh product. In conclusion, the herein presented product was addressed as an innovation with multiple possible applications in several recipes.info:eu-repo/semantics/publishedVersio

Photoreduction of CO2 with a Formate Dehydrogenase Driven by Photosystem II Using a Semi-artificial Z-Scheme Architecture.

Solar-driven coupling of water oxidation with CO2 reduction sustains life on our planet and is of high priority in contemporary energy research. Here, we report a photoelectrochemical tandem device that performs photocatalytic reduction of CO2 to formate. We employ a semi-artificial design, which wires a W-dependent formate dehydrogenase (FDH) cathode to a photoanode containing the photosynthetic water oxidation enzyme, Photosystem II, via a synthetic dye with complementary light absorption. From a biological perspective, the system achieves a metabolically inaccessible pathway of light-driven CO2 fixation to formate. From a synthetic point of view, it represents a proof-of-principle system utilizing precious-metal-free catalysts for selective CO2-to-formate conversion using water as an electron donor. This hybrid platform demonstrates the translatability and versatility of coupling abiotic and biotic components to create challenging models for solar fuel and chemical synthesis.ERC Consolidator Grant, EPSRC, Christian Doppler Research Association (Austrian Federal Ministry for Digital and Economic Affairs and the National Foundation for Research, Technology and Development), the OMV group, Deutsche Forschungsgemeinschaft, European Union's Horizon 2020 MSCA, Fundação para a Ciência e Tecnologia (Portugal), COMPETE2020/POCI and European Union’s Horizon 202