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In this study, the antioxidant properties of chestnut (flowers, leaves, skins and fruits) extracts were evaluated through several biochemical assays: DPPH (2,2-diphenyl-1-picrylhydrazyl) radical-scavenging activity, reducing power, inhibition of b-carotene bleaching, inhibition of oxidative hemolysis in erythrocytes, induced by 2,2 0 -azobis(2-amidinopropane)dihydrochloride (AAPH), and inhibition of lipid peroxidation in pig brain tissue through the formation of thiobarbituric acid-reactive substances (TBARS). These assays have been extensively studied as models for the peroxidative damage in biomembranes. The EC 50 values were calculated for all the methods in order to evaluate the antioxidant efficiency of each chestnut extract. The phenol and flavonoid contents were also obtained. Chestnut skins revealed the best antioxidant properties, presenting much lower EC 50 values, particularly for lipid peroxidation inhibition in the TBARS assay. Furthermore, the highest antioxidant contents (polyphenols and flavonoids) were found for these extracts.

Coleostephus myconis (L.) Rchb.f. (Asteraceae) is a species with ruderal growth and persistence in abandoned soils, being characterized for its plentiful yellow flowering between March and August. Despite its botanical relevance, C. myconis had never been studied neither for its antioxidant activity, nor individual phenolic compounds. Herein, the antioxidant activity of different botanical parts: stems and leaves (green parts), floral buds, flowers in anthesis and senescent flowers, was studied in selected extracts

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a b s t r a c tThe antioxidant properties of different almond cultivars (cv.), either regional (Casanova, Duro Italiano, Molar, Orelha de Mula and Pegarinhos cv.) or commercial (Ferraduel, Ferranhês, Ferrastar and Guara cv.) were evaluated through several chemical and biochemical assays: DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging activity, reducing power, inhibition of b-carotene bleaching, inhibition of oxidative hemolysis in erythrocytes, induced by 2,2 0 -azobis(2-amidinopropane)dihydrochloride (AAPH), and inhibition of thiobarbituric acid reactive substances (TBARS) formation in brain cells, all used as models for the lipid peroxidation damage in biomembranes. The EC 50 values were calculated for all the methods in order to evaluate the antioxidant efficiency of each almond cultivar. Bioactive compounds such as phenols and flavonoids were also obtained and correlated to antioxidant activity. The results obtained were quite heterogeneous, revealing significant differences among the cultivars assayed. Duro Italiano cv. revealed better antioxidant properties, presenting lower EC 50 values in all assays, and the highest antioxidants contents. The protective effect of this cultivar on erythrocyte biomembrane hemolysis was maintained during 4 h.

a b s t r a c tOxidative stress has a relevant part in the etiology of several diseases and metabolic disorders, being reasonable to expect that antioxidant compounds might have beneficial effects in health maintenance or disease prevention. Antioxidant compounds might be isolated and characterized from different plant constituents, such as roots, stems, bark, leaves, flowers, fruits and seeds, using proper extraction methods. The Asteraceae family has a worldwide distribution, with special relevance in the Mediterranean, Eastern Europe and Asia Minor, being acknowledged about 25 000 species integrated in approximately 1000 genera. In addition to the anti-inflammatory, analgesic and antipyretic potential of some of these species, their high antioxidant power, as proven in research works with extracts (of roots, stems, bark, leaves, flowers, fruits and seeds) should be highlighted. Herein, the Asteraceae species with highest potential as sources of natural antioxidants with potential uses in medicine and in pharmaceutical, cosmetic and food industries were identified. The species were selected based on their botanical representativeness, being identified the 9 most relevant species: Achillea millefolium L., Acmella oleraceae Murr., Artemisia absinthium L., Bidens pilosa L., Carthamus tinctorius L., Inula crithmoides L., Matricaria recutita L., Otanthus maritimus L. and Parthenium hysterophorus L.. With the obtained information, it could be concluded that the bioactivity of the selected Asteraceae species lacks a complete characterization, constituting a research scope with great potential to be exploited in the development of dietary supplements, bioactive food ingredients or pharmaceutical based products with application in food industry, dermocosmetics or medicine.

Four Portuguese chestnut cultivars from the "Castanha da Terra Fria" protected designation of origin were selected: Aveleira, Boa Ventura, Judia and Longal. The nutritional parameters (moisture, fat, protein, carbohydrates, ash and energy) as well as fibers (neutral detergent fiber, acid detergent fiber, acid detergent lignin and cellulose) were characterized. Moisture was the major component followed by carbohydrates, protein and fat, resulting in an energetic value lower than 195 kcal/100 g of fresh fruit. In order to find significant differences among cultivars, the lipidic fraction was studied in detail. Fatty acids (FA) were determined by gas-liquid chromatography with flame ionization detection, revealing a clear prevalence of C18:1 and C18:2, two FA very well-known due to their beneficial effects on human health, e.g., in the prevention of cardiovascular diseases. A triacylglycerols (TAG) profile was obtained by reversed-phase high-performance liquid chromatography with evaporative light-scattering detection. TAG analysis is very important because it furnishes highly specific information due to genetic control of the stereospecific distribution of FA on the glycerol molecule. OLL, PLL, OOL and POL were the major compounds. As far as we know this is the first complete characterization of TAG in chestnut. The obtained data were screened through an analysis of variance (to evaluate the accuracy of the method as well as the uniformity of results for each cultivar) and a discriminant analysis (DA), which gave good results, once that, in some cases, the four cultivars were clustered in four individual groups, obtained through the definition of two DA dimensions.