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Projeto de investigação
Chemistry Center - Vila Real
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Kaolin foliar spray induces positive modifications in volatile compounds and fruit quality of Touriga-Nacional red wine
Publication . Dinis, Lia Tânia; Pereira, Sandra; Fraga, Irene; Rocha, Sílvia M.; Costa, Carina; Martins, Cátia; Vilela, Alice; Arrobas, Margarida; Moutinho-Pereira, José
Solar radiation and temperature play crucial roles in grapevine metabolic processes and are known to have a positive impact on grape berry composition; however, excessive exposure to these factors can be detrimental. Kaolin-based particle film technology has emerged as a valuable solution for mitigating the effects of heat and water stresses in vineyards. This work aimed to evaluate the effects of kaolin application on the phenolic composition, chromatic characteristics, oenological parameters, volatile compounds and sensory profile of red wine. The study was carried out in one growing season in the commercial vineyard “Quinta dos Aciprestes” in the Douro Superior sub-region. Twelve rows in triplicate of the Touriga-Nacional variety underwent foliar kaolin treatment (applied at the pre-veraison stage, at the manufacturerrecommended and -tested dosage of 5 % (w/v)), and another twelve rows comprised the nontreated control group. Kaolin increased the phenolic compound and tartaric acid concentrations (2.4 % and 20.8 % respectively), total acidity (2.4 %), the deep reddish colour of the berries, total and coloured anthocyanin (2.8 %), and total and polymeric pigments (3.6 %); meanwhile, a decrease was observed in pH (-1.4 %) and alcoholic degree (-4.8 %). No significant differences were observed in any sensory parameters between the wine from the kaolin-treated and control vines, but the tasters found the aroma of the former to be fruitier and more complex, with an agreeable acidic taste and persistence. It was possible to group the volatile compounds into two distinct groups based on the results of the Pearson’s correlation matrix. This grouping corresponds to the sensory descriptors common to each of the respective volatiles. Overall, the results further support the potential efficacy of utilising kaolin to alleviate summer-related stress in grapevines.
The influence of Castanea sativa Mill. flower extract on hormonally and chemically induced prostate cancer in a rat model
Publication . Nascimento-Gonçalves, Elisabete; Seixas, Fernanda; Silva, Marcelo Aparecido de Souza; Fardilha, Margarida; Ferreira, Rita; Neuparth, Maria João; Faustino-Rocha, Ana; Colaço, B.; Venâncio, Carlos; Barros, Lillian; Ferreira, Isabel C.F.R.; Oliveira, Mónica M.F.; Peixoto, Francisco P.; Rosa, Eduardo; Oliveira, Paula A.
Prostate cancer (PCa) is one of the most common cancers in men, with a huge impact on their health. The use of Castanea sativa Mill. flowers (CFs) in beverages has been reported, through ancestral claims, as having health benefits. In vitro research has evidenced the properties of CFs, such as antitumor and antioxidant activities. This study aimed to evaluate the effects of CF extract in an animal model of PCa. Forty male Wistar Unilever rats were randomly assigned to four groups: control, induced, control + CF, and induced + CF groups. Animals from the induced groups were exposed to a multistep protocol for PCa induction. The CF extract, rich in trigalloyl-HHDP-glucoside and obtained via decoction, was administered to the CF groups in drinking water (3 mg per animal per day) for 49 weeks. Animals were sacrificed at 61 weeks of age. Regarding the effects of CFs on dorsolateral prostate tumorigenesis, no significant differences were observed between the induced and induced + CF groups. However, animals exposed to the CF extract showed fewer inflammation areas on the dorsolateral prostate lobe than those not exposed to CF. Moreover, the CF extract alleviated the hepatic oxidative stress associated with the multistep protocol, resulting in lower levels of lipid peroxidation. These results suggest that CF extract has antioxidant and anti-inflammatory properties. This journal is.
An experimental analysis on the thermal performance of rammed earth walls
Publication . Luso, Eduarda; Cabello, Isabel; Silva, Rui A.; Briga-Sá, Ana
Earth has been used as a building material since the beginning of civilizations and its utilization was widespread to most regions of the world, promoted by the high availability, easy access and low cost of the material. As result of the generalised use of raw earth as building material, many earthen building techniques were developed through time, where adobe masonry, rammed earth and wattle-and-daub are among the most important. Currently, it is estimated that one quarter of the world's population lives in buildings made of earth. However, during the last century, earthen materials fell into disuse in several developed countries with the popularization of concrete, steel and fire bricks. Nevertheless, earthen architecture has been receiving increasing attention in the last few decades, driven by its green building potential and by other features of earthen materials, which includes, among others, unique aesthetics and hygrothermal regulation capacity.
Several studies have been developed to characterize earthen solutions concerning physical and mechanical properties. However, regarding the thermal behaviour, it is known that the thermal conductivity of rammed earth is a parameter that depends on the characteristics of the soil (particle size distribution, mineralogy, etc.) and moisture content. Thus, given the soils variability, it becomes clear that further investigation should be addressed to characterize the thermal performance of rammed earth solutions, contributing to define more accurate thermal conductivity values for the design of rammed earth buildings. On this regard, this paper presents an experimental study that aims to characterize the thermal behaviour of rammed earth built with different soils and with different thicknesses. A continuous measurement allowed to obtain heat fluxes, inner surface temperatures and the thermal transmission coefficient of the tested rammed earth walls solutions. The results obtained so far confirmed that the type of soil and thickness significantly influences the thermal behaviour of the earthen material. It was also observed that the thermal transmission coefficient of a 50 cm thick wall is about 30% lower than the one verified for the wall with 35 cm, built with the same soil.
UV Radiation: Applications on Surfaces in the Food Industry
Publication . Maioto, Rita; Santos, Stefanie; Dias, Albino A.; Aires, Cristina; Inês, António; Sedrine, Nabiha Ben; Mendes, Paulo; Rodrigues, Paula; Sampaio, Ana
Ultraviolet radiation, particularly in the UVC sub-band 200–280 nm, is a non-thermal disinfection technology capable of inactivating a broad spectrum of microorganisms primarily through nucleic acid damage and protein oxidation. Its effectiveness depends on wavelength, irradiance, exposure time, environmental conditions, and microbial characteristics, such as species and repair capacity. In food processing environments, where equipment surfaces and packaging materials are critical control points for microbial contamination, UVC offers several advantages, including the absence of chemical residues, and compatibility with sustainable sanitization strategies. However, efficacy is strongly influenced by surface properties. Smooth, non-porous, reflective materials (stainless steel, glass), and photocatalytic metal coatings, enhance UVC performance, whereas rough, porous, or fibrous surfaces reduce penetration and create shadowing effects that limit microbial inactivation. This review synthesizes current evidence on UV-based decontamination in the food industry, highlighting both its potential and limitations. The findings emphasize that, although UVC radiation is effective in microbial control, its implementation must consider the complex interactions between surface properties, microorganisms and irradiation parameters, requiring optimization for each environment and application. Further research is therefore needed into: (i) wavelength-tuned systems, (ii) hybrid technologies (UV–plasma or UV-photocatalysis), (iii) material integrity and durability of materials under repeated exposure, and (iv) emerging alternative light sources.
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Entidade financiadora
Fundação para a Ciência e a Tecnologia
Programa de financiamento
6817 - DCRRNI ID
Número da atribuição
UIDP/00616/2020