Browsing by Author "Gominho, Jorge"
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- Chemical effects of a mild torrefaction on the wood of eight Eucalyptus speciesPublication . Araújo, Solange de Oliveira; Neiva, Duarte M.; Gominho, Jorge; Esteves, Bruno; Pereira, HelenaThe torrefaction is a thermal pre-treatment to improve biomass quality for biofuel applications. In this study, the effects of a mild torrefaction (T) on eight euca- lypt species ( Eucalyptus botryoides, E. globulus, E. grandis, E. maculata, E. propinqua, E. rudis, E. saligna and E. vimi- nalis ) have been compared. Namely, the mass loss (ML), the equilibrium moisture content (EMC), density and chemical composition were determined and FTIR spectra were recorded of the initial and torrefied woods (TWs). The average ML was 11% and the heat-treated woods had an overall 10% density decrement. All the TW had 50% lower EMC compared to untreated wood samples (W). Elemen- tal composition showed that carbon content increased from 48% to 53% and the oxygen/carbon ratio decreased from 0.80 to 0.65. The chemical changes induced by T included an increment of extractives, a 20% higher lignin content and a 16% lower holocellulose content in relation to W. The hemicelluloses modification is manifested by a decrease of xylose, galactose, and acetyl groups in TWs. The fourier transform infrared (FTIR) spectra of the different wood species were very similar, and reflected in a uniform manner the chemical changes upon T. Because of the similar reaction of the eucalypt species, they can also be used in form of mixed eucalypt feedstock as biofuel.
- Potential Applications of the Cytisus Shrub Species: Cytisus multiflorus, Cytisus scoparius, and Cytisus striatusPublication . Caramelo, Débora; Barroca, Celina; Guiné, Raquel; Gallardo, Eugenia; Anjos, Ofélia; Gominho, JorgeCytisus spp. is present throughout the Portuguese territory. Although most of these species are considered native in Portugal, at least one species has already been reported as invasive in other parts of the world. Different measures of control have been investigated, and the application of herbicides is the most commonly used. This review gathers information about the biochemical profile and analytical methods used for the evaluation of the potential bioactivities of three species of the genus Cytisus, better known as brooms, which were used in traditional medicine through the production of infusions and decoctions for the treatment of several health problems, mainly due to their high value of phenolic compounds. However, little research has been conducted on its biological activities as a potential antioxidant, anti-inflammatory, and antimicrobial agent. Furthermore, one species (Cytisus striatus) has not been subjected to extensive research in identifying chemical compounds and evaluating their potential bioactivities. This species (known as the Portuguese broom) has a great expression in one of the forest typologies with a considerable percentage in Portugal. This research work is essential to encourage a scientific and sustainable valorisation of Cytisus spp. (namely C. striatus), which will consequently contribute to forest cleaning and management to reduce the risk of wildfires.