Percorrer por autor "Asensio-S.-Manzanera, M. Carmen"
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- Actividade antioxidante e composição em fenóis totais de dez novas variedades de feijão do ITACYLPublication . Afonso, Sílvia Marlene Esteves; Oliveira, Ivo; Ramalhosa, Elsa; Asensio-S.-Manzanera, M. Carmen; Asensio, Carmen; Bento, Albino; Pereira, J.A.O feijão (Phaseolus ltztlgaris L.) é uma leguminosa largamente consumida no mundo, estando-lhe associadas diferentes propriedades nutricionais. Nas últimas décadas o Instituto Tecnológico Agrário de Castela e Leão (ITACyL) tem-se dedicado ao desenvolvimento de novas variedades de feijão. Neste sentido, com o presente trabalho procedeu-se à avaliação do teor em fenóis totais, e da actividade antioxidante através do efeito bloqueador dos radicais livres de DPPH (2,2-difenil-1-picrilhidrazilo) em dez variedades de feijão desenvolvidas naquele organismo (Almonga, Cárdeno, Cardina, Casasola, Corcal, Curruquilla, Moradillo, Tafioga, Tremaya e Tropical). O teor em fenóis totais foi muito diferente entre variedades oscilando entre 4.19±0.18 (variedade Almonga) e 90.85±2.04 (variedade Tafioga) equivalentes de ácido cafeico/100 g de feijão, enquanto os valores de ECso variaram entre 0.17±0.06 (variedade Tafioga) e 20.58±3.93 (variedade Casasola) mg de extracto aquoso liofilizado de feijão/ ml. De maneira geral as amostras com maior teor em fenóis totais conduziram a menores valores de ECso estando os valores significativamente correlacionados (r2= 0.677; p =0.003).
- Actividade antioxidante e composição em fenóis totais de dez variedades de feijão do ITACYLPublication . Afonso, Sílvia Marlene Esteves; Oliveira, Ivo; Ramalhosa, Elsa; Asensio-S.-Manzanera, M. Carmen; Asensio, Carmen; Bento, Albino; Pereira, J.A.O feijão (Phaseolus ltztlgaris L.) é uma leguminosa largamente consumida no mundo, estando-lhe associadas diferentes propriedades nutricionais. Nas últimas décadas o Instituto Tecnológico Agrário de Castela e Leão (ITACyL) tem-se dedicado ao desenvolvimento de novas variedades de feijão. Neste sentido, com o presente trabalho procedeu-se à avaliação do teor em fenóis totais, e da actividade antioxidante através do efeito bloqueador dos radicais livres de DPPH (2,2-difenil-1-picrilhidrazilo) em dez variedades de feijão desenvolvidas naquele organismo (Almonga, Cárdeno, Cardina, Casasola, Corcal, Curruquilla, Moradillo, Tafioga, Tremaya e Tropical). O teor em fenóis totais foi muito diferente entre variedades oscilando entre 4.19±0.18 (variedade Almonga) e 90.85±2.04 (variedade Tafioga) equivalentes de ácido cafeico/100 g de feijão, enquanto os valores de ECso variaram entre 0.17±0.06 (variedade Tafioga) e 20.58±3.93 (variedade Casasola) mg de extracto aquoso liofilizado de feijão/ ml. De maneira geral as amostras com maior teor em fenóis totais conduziram a menores valores de ECso estando os valores significativamente correlacionados (r2= 0.677; p =0.003).
- Antioxidant activity of twenty wild Spanish Thymus mastichina L. populations and its relation with their chemical compositionPublication . Delgado, Teresa; Marinero, Pilar; Asensio-S.-Manzanera, M. Carmen; Asensio, Carmen; Herrero, Baudilio; Pereira, J.A.; Ramalhosa, ElsaThe antioxidant activity and chemical composition of essential oils and methanolic extracts of twenty Spanish Thymus mastichina L. populations were studied. Both essential oils and methanolic extracts possessed antioxidant properties. However, the total phenol contents of the methanolic extracts varied between 2.90 and 9.15mg GAE/g extract and the EC 25 values of DPPH free radical scavenging activity between 0.90 and 3.45mg/mL for the methanolic extracts and 78-241mg/mL for essential oils, these showing low antioxidant potential. Actually, in essential oils the main compound determined was the 1,8-cineole (56.8-69.6%), whereas thymol, γ-terpinene, terpinolene and geraniol (species with considerable DPPH scavenging activity) were observed in low amounts. Concerning methanolic extracts, rosmarinic acid was the most abundant polyphenol (1.70-9.85mg/g), followed by methoxysalicylic acid, apigenin, kaempferol and luteolin.
- By-product of Lavandula latifolia essential oil distillation as source of antioxidantsPublication . Méndez-Tovar, Inés; Herrero, Baudilio; Pérez-Magariño, Silvia; Pereira, J.A.; Asensio-S.-Manzanera, M. CarmenThe objective of this work was to evaluate the antioxidant properties of Lavandula latifolia waste obtained after essential oil distillation. Samples of 12 wild populations of the Lavandula genus collected between 2009 and 2010 were hydrodistilled and their by-products were analyzed using the FolineCiocalteu, free radical scavenging activity (2,2-diphenyl-1- picrylhydrazyl), and the ferric reducing antioxidant power (FRAP) methods. Rosmarinic acid, apigenin, and luteolin contents were analyzed by high-performance liquid chromatographyediode array detection. The mean of total phenolic content ranged from 1.89 ± 0.09 mg gallic acid equivalents/g dry weight to 3.54 ± 0.22 mg gallic acid equivalents/ g dry weight. The average value of the half maximal effective concentration (EC50) for scavenging activity ranged from 5.09 ± 0.17 mg/mL to 14.30 ± 1.90 mg/mL and the variability of the EC50 in FRAP ranged from 3.72 ± 0.12 mg/mL to 18.55 ± 0.77 mg/mL. Annual variation was found among this samples and the environmental conditions of 2009 were found to be more favorable. The plants collected from Sedano showed the highest antioxidant power. Our results show that rosmarinic acid and apigenin in L. latifolia contributed to the antioxidant properties of the waste. In conclusion, the by-product of the distillation industry could be valorizing as a source of natural antioxidants.
- Effect of olive trees density on the quality and composition of olive oil from cv. ArbequinaPublication . Rodrigues, Nuno; Casal, Susana; Peres, António M.; Baptista, Paula; Bento, Albino; Martín, Hugo; Asensio-S.-Manzanera, M. Carmen; Pereira, J.A.The number of plants per hectare is a key factor for olive tree productivity. Nevertheless, information about the effect of tree density on olive oil quality and composition is scarce. Thus, the effect of planting densities of cv. Arbequina trees on olive oil quality and composition was studied along the first four years of production. Two types of planting tree arrangements were evaluated, namely olive trees planted at different distances within a row (2.0 m; 1.5 m; 1.25 m; and 1.0 m, fixing the space between rows equal to 4.0 m) or at different distances between rows (4.0 m; 3.5 m; and 3.0 m, fixing the space within the same row at 1.5 m), which led to planting densities from 1250 to 2500 trees ha−1. The results indicated that the quality parameters, composition, antioxidant activity and oxidative stability were significantly affected by the densities of plants and the crop year (Pvalue < 0.0001, for one-way ANOVA). An increase of plants in the row and between rows showed a tendency for a slight increase of free acidity, and a reduction of the peroxide value and of the extinction specific coefficients. Fatty acid composition was also affected, with a tendency for the decrease of C16:0, C18:0, SFA and PUFA, and an increase of C18:1, C18:2 and MUFA. The antioxidant activity and the oxidative stability also showed a reduction trend. For all parameters evaluated, the crop year had a marked influence. The year of production had significant statistical effects on the evaluated parameters, which could be related to agro-climatic factors.
- Influence of spike lavender (Lavandula latifolia Med.) essential oil in the quality, stability and composition of soybean oil during microwave heatingPublication . Rodrigues, Nuno; Malheiro, Ricardo; Casal, Susana; Asensio-S.-Manzanera, M. Carmen; Bento, Albino; Pereira, J.A.Lipids oxidation is one of the main factors leading to quality losses in foods. Its prevention or delay could be obtained by the addition of antioxidants. In this sense the present work intend to monitor the protective effects of Lavandula latifolia essential oil during soybean oil microwave heating. To achieve the proposed goal quality parameters (free acidity, peroxide value, specific coefficients of extinction and ΔK), fatty acids profile, tocopherols and tocotrienols composition, antioxidant activity and oxidative stability were evaluated in soybean oil with and without spike lavender essential oils (EO) submitted to different microwave heating exposure times (1, 3, 5, 10 and 15 min; 1000 Watt) with a standard domestic microwave equipment. Microwave heating induced severe quality and composition losses, mainly above 3 min of microwave heating, regardless the sample tested. However, spike lavender EO addition counteracts the oxidation comparatively to control oils, by presenting enhanced values in quality parameters. A higher protection in unsaturated fatty acids loss was also observed as well as a higher antioxidant activity and oxidative stability. The microwave heating effects were clearly different in the samples with essential oils addition, allowing discrimination from plain soybean oils by a principal component analysis, being also capable to discriminate the different heating times tested within each sample.
- Olive oil characteristics of eleven cultivars produced in a high-density grove in Valladolid province (Spain)Publication . Rodrigues, Nuno; Casal, Susana; Pinho, Teresa; Cruz, Rebeca; Baptista, Paula; Martín, Hugo; Asensio-S.-Manzanera, M. Carmen; Peres, António M.; Pereira, J.A.The olive oil composition of eleven cultivars (cvs. Arbequina, Arbosana, Arroniz, Cornicabra, Frantoio, Hojiblanca, Manzanilla, Picual, Picudo, Redondilla and Royuela) cultivated in a high-density olive grove located in a non-traditional producing region (Valladolid, Spain) was studied during four consecutive crop seasons. The results showed that the 122 monovarietal olive oils studied could be classified as extra virgin oils, according to the quality parameters. Furthermore, the olive cultivar had a marked effect on the chemical composition and antioxidant activity. In general, olive oils from cvs. Picual and Cornicabra showed the highest total phenolic contents, oxidative stability, and tocopherols contents, whereas the worst results for oxidative stability were observed for cv. Redondilla olive oils, probably associated to the lowest contents of phenolics and tocopherols and the highest amounts of polyunsaturated fatty acids. Finally, it was found that, despite the different crop years evaluated, the quality-chemical profiles could be used to successfully discriminate the monovarietal oils under study (linear discriminant analysis sensitivities: 92 ± 5% for the repeated K-fold cross-validation), using the data of 15 non-redundant variables identified by the simulated annealing variable selection algorithm.
- Thymus masticina L. – Composição e bioactividade de exemplares com diferentes origens geográficasPublication . Delgado, Teresa; Pilar, Marinero; Asensio-S.-Manzanera, M. Carmen; Asensio, Carmen; Herrero, Baudilio; Pereira, J.A.; Ramalhosa, ElsaO tomilho (Thymus sp.) e geralmente usado como especiaria e/ou erva medicinal com diversas propriedades farmacológicas, tais como anti-espasmódicas, anti-sépticas, anti-tússicas, expectorantes, entre outras. Os óleos essenciais extraídos do tomilho tem também encontrado uso na dieta humana, uma vez que tem sido demonstrada actividade antimicrobiana face a microrganismos patogénicos, tais como Staphylococcus aureus, Helicobacter pylori e Candida albicans.