João C M Barreira

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The effect of storage at two temperatures (5±1 and 25±1 °C and 60-70±5% RH for both temperatures) on marketability and quality features of dry bulbs of local landrace "Vatikiotiko", "Sivan F1", "Red Cross F1" and "Creamgold" was examined. During storage measurements for fresh and dry weight of bulbs, tunic and flesh color, bulb firmness, nutritional value(More)
A high variety of plant species are often proposed as potential natural sources of specific bioactive components, with emphasis in phenolic compounds. However, the ability to produce a determined phytochemical might be variable, even among species with close phylogeny. Furthermore, the metabolic dynamics vary greatly according to phenologic factors. Herein,(More)
A comparative study between the antioxidant properties of peel (flavedo and albedo) and juice of some commercially grown citrus fruit (Rutaceae), grapefruit (Citrus paradisi), lemon (Citrus limon), lime (Citrusxaurantiifolia) and sweet orange (Citrus sinensis) was performed. Different in vitro assays were applied to the volatile and polar fractions of peels(More)
It was previously demonstrated that gamma irradiation was the processing technology with the highest capacity to maintain the chemical profile of fresh Macrolepiota procera wild mushroom, when compared to freeze-dried or oven-dried samples. Herein, it was aimed to evaluate gamma irradiation effects on processed samples. Chemical composition and antioxidant(More)
Herbal infusions and decoctions in water are some of the most commonly consumed beverages in the world. Although water is not a good solvent for many of the active components in herbs, liquid preparations are rich in several bioactive compounds. Most of them have powerful antioxidant activity and have been related to medicinal herbs' properties. Herein,(More)
Natural matrices are important sources of new antitumor and antimicrobial compounds. Species such as Laurus nobilis L. (laurel) might be used for this purpose, considering its medicinal properties. Herein, in vitro activity against human tumor cell lines, bacteria, and fungi was evaluated in enriched phenolic extracts. Specifically, methanol and aqueous(More)
Chestnut (Castanea sativa Miller) is an important food resource all over the world. In the present study, it is intended to evaluate if the application of gamma irradiation doses ≤ 3 kGy maintain chestnuts chemical and nutritional profiles unaffected. Furthermore, possible interactions among irradiation dose and storage time were accessed using linear(More)
Several dietary supplements claim medicinal benefits due to their composition in hydrophilic and lipophilic molecules, natural extracts or synthetic compounds with antioxidant properties. In the present work, the antioxidant activity of selected supplements taken in pills, capsules or infusions were studied either individually or combined. Linear(More)
Edible flowers are used in food preparations, being also recognized for their beneficial effects on human health. Nevertheless, these species are highly perishable, and irradiation treatment might be applied to ensure food quality and increase their shelf life. Viola tricolor L. is a typical edible flower, with multiple applications and biological(More)
Several herbal beverages claim medicinal benefits due to their antioxidant properties. However, operational factors such as the extracted herbal component, preparation method or concentration levels, might influence their biological activity. To assess this effect, the antioxidant activity of beverages prepared with Camellia sinensis, Aspalathus linearis or(More)