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.

2024Journal article

Open access

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.

2021Journal article

Open access