Strategic Project - LA 6 - 2011-2012

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Publications

Triacylglycerols profiling as a chemical tool to identify mushrooms submitted to gamma or electron beam irradiation

Publication . Fernandes, Ângela; Barreira, João C.M.; Antonio, Amilcar L.; Martins, Anabela; Ferreira, Isabel C.F.R.; Oliveira, Beatriz

In order to define irradiation treatment as a routine conservation methodology, it is imperative to develop chemometric indicators with the ability to distinguish irradiated from unirradiated foodstuffs. Electron spin resonance, photostimulated luminescence and thermoluminescence methods were employed to monitor radiation-induced markers, as well as different chemical compounds produced from the lipidic fraction of different foodstuffs. Apart from these methods, the specificity of triacylglycerol profiles has previously been detected in mushroom species, as has the effect of irradiation treatment in the triacylglycerol profiles of chestnut. Accordingly, the feasibility of using this as a chemometric indicator of irradiated mushrooms was evaluated. In line with the obtained results in literature, the effects of each type of irradiation were significantly different, as can be concluded from the correlations among discriminant functions and variables within each statistical test. Triacylglycerol profiling proved to be a useful tool to detect irradiated mushrooms, independently of the species or irradiation source, especially for doses above 1 kGy.

2014Journal article

Open access

Wild and commercial samples of Achillea millefolium L.: proximate composition and individual compounds obtained by chromatography

Publication . Dias, Maria Inês; Barros, Lillian; Carvalho, Ana Maria; Alves, Rita C.; Oliveira, Beatriz; Ferreira, Isabel C.F.R.

Medicinal plants have been used since ancient times and emerge nowadays as alternative to synthetic products, due to their richness in bioactive compounds. In a society that requires new and safer products, due to the growing concern with health and nutrition, medicinal plants are now being used not only in traditional medicine but also in a number of food and pharmaceutical products [1]. Achillea millefolium L., belongs to Asteraceae family and it is commonly known as yarrow, very common in mountain meadows, pathways, crop fields and homegardens. Widespread across Europe, it’s infusion, decoction and alcoholic extract are widely used as an herbal remedy to treat digestive problems, diabetes, hepato-biliary diseases and amenorrhea, showing also antitumor, antimicrobial, anti-inflammatory and antioxidant properties [2,3]. In the present work, commercial and wild samples of A. millefoilum were characterized regarding the proximate composition and individual compounds namely, free sugars, organic acids, fatty acids and tocopherols, determined by chromatographic techniques coupled to different detectors (HPLC-RI, HPLC-DAD, GC-FID e HPLC-fluorescence, respectively). Carbohydrates, followed by proteins, were the major macronutrients in both samples. Commercial yarrow gave higher content of fat (and saturated fatty acids, mainly palmitic acid C16:0), proteins, ash, energetic value and total sugars (including fructose, glucose, sucrose and trehalose). Wild sample revealed higher levels of carbohydrates; it also showed raffinose (not detected in the commercial sample), polysaturated fatty acids (mainly linoleic acid, C18:2n-6) and organic acids (including malic, oxalic and quinic acids). Regarding tocopherols, both samples showed similar profile, although the wild sample gave higher levels of total tocopherols; γ-Tocopherol was the most abundant isoform; δ-Tocopherol was not found in the samples. Data obtained are clear evidence that traditional medicinal plants can be used not only in household products but also in pharmaceutical and food industry as a source of new and safer bioactive compounds.

2014Conference object

Open access

Efeitos do processamento em parâmetros nutricionais e químicos do cogumelo silvestre Macrolepiota procera

Publication . Fernandes, Ângela; Antonio, Amilcar L.; Barreira, João C.M.; Martins, Anabela; Oliveira, Beatriz; Ferreira, Isabel C.F.R.

Tendo em conta a sua natureza perecível, os cogumelos têm que ser processados para aumentar o seu tempo de prateleira. No presente trabalho, foram avaliados os efeitos de diferentes tecnologias de processamento (congelamento, secagem e irradiação) na composição química de amostras silvestres de Macrolepiota procera, obtidas na região de Trás-os-Montes. O congelamento foi efetuado a -20º C, a secagem foi realizada a 30 º C em estufa e a irradiação foi feita num equipamento com quatro fontes de 6°Co a 0,5 ± O, 1 kGy de radiação gama, à razão de 2,3 ± O, I kGy h-1. Determinou-se o valor nutricional das amostras processadas e de amostras controlo (sem processamento) seguindo os procedimentos oficiais, tendo-se também obtido os perfis em ácidos gordos, tocoferóis, mono e oligossacáridos por técnicas cromatográficas. O processamento induziu algumas alterações nos parâmetros nutricionais: o teor cm água foi superior nas amostras congeladas c secas, os lípidos e o valor energético foram superiores nas amostras irradiadas, enquanto as amostras congeladas apresentaram maior teor de proteínas, as amostras secas maior quantidade de cinzas e as amostras não processadas maior teor de glúcidos. As amostras secas e irradiadas apresentaram maiores percentagens de ácidos gordos (AG) saturados, em especial Cl 6:0, enquanto os AG monoinsan1rados (cm especial C \8: I) foram mais abundantes nas amostras irradiadas e os AG polinsaturados atingiram valores máximos nas amostras congeladas, com destaque para C 18:2. Em relação ao perfil em tocoferóis, as diferenças mais assinaláveis foram as maiores quantidades de β-, Υ- e δtocoferol respetivamente nas amostras secas, irradiadas e não processadas. As amostras secas revelaram maior quantidade de açúcares livres, sendo o manitol predominante; por outro lado, as concentrações mais elevadas de trealose e melezitose foram detetadas em amostras irradiadas, enquanto a frutose foi mais elevada nas amostras congeladas. Os resultados obtidos após análise de componentes principais, considerando todas as alterações de forma global e integrada, indicam, a partir da análise da localização espacial dos objetos c variáveis, que a congelação e a secagem provocaram diferenças mais significativas nos parâmetros químicos avaliados, quando comparadas com o efeito da irradiação. Assim, esta tecnologia de processamento evidenciou maior capacidade para manter o perfil químico e nutricional das amostras não processadas (controlo). Desta forma, a radiação gama pode ser considerada como uma tecnologia de elevado potencial na conservação de cogumelos.

2013Conference object

Open access

Gamma and electron-beam irradiation as viable technologies for wild mushrooms conservation: effects on macro- and micro-elements

Publication . Fernandes, Ângela; Barreira, João C.M.; Antonio, Amilcar L.; Rafalski, Andrzej; Morales, Patricia; Férnandez-Ruiz, Virginia; Oliveira, Beatriz; Martins, Anabela; Ferreira, Isabel C.F.R.

The consumption of mushrooms is increasing all over the world as a result of their sensorial and nutritional qualities. Among their nutrients, mushrooms present high levels of macro- and micro-elements. The qualitative composition in these elements is, however, often unknown. Mushrooms are known also as being very perishable products. Gamma rays or electron-beam irradiation has been applied to improve their shelf life and decrease health hazards caused by microorganisms. In addition, the effects of irradiation on the physicochemical and nutritional parameters of wild mushrooms have been studied by our research group. Nevertheless, the effects on essential macro- and micro-elements of these natural matrices are still unknown. The effects of gamma and electron-beam irradiation on the macro- and micro-elements profiles were evaluated in Boletus edulis, Hydnum repandum and Macrolepiota procera. The same elements were detected in the three species with some quantitative differences. The profiles obtained allowed the definition of proper dietary intakes, thus preventing undesirable effects derived from consuming mushrooms in quantities that exceed threshold levels of these minerals. The applied irradiation doses did not show a systematic effect on the macro- and micro-elements profiles, except for the 10 kGy. Accordingly, irradiation treatment, using gamma rays or electron beam up to 6 kGy, is a suitable technique to disinfest and/or decontaminate wild mushrooms, independently of their species or physical state.

2016Journal article

Restricted access

Kale extract increases glutathione levels in V79 cells, but does not protect them against acute toxicity induced by hydrogen peroxide

Publication . Fernandes, Fátima; Sousa, Carla; Ferreres, Frederico; Valentão, Patrícia; Remião, Fernando; Pereira, J.A.; Andrade, Paula B.

This study aims to evaluate the antioxidant potential of extracts of Brassica oleracea L. var. acephala DC. (kale) and several materials of Pieris brassicae L., a common pest of Brassica cultures using a cellular model with hamster lung fibroblast (V79 cells) under quiescent conditions and subjected to H₂O₂ induced oxidative stress. Cytotoxicity was evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay and glutathione was determined by the 5,5'-dithiobis(2-nitrobenzoic acid) (DTNB)-oxidized glutathione (GSSG) reductase recycling assay. The phenolic composition of the extracts was also established by HPLC-DAD. They presented acylated and non acylated flavonoid glycosides, some of them sulfated, and hydroxycinnamic acyl gentiobiosides. All extracts were cytotoxic by themselves at high concentrations and failed to protect V79 cells against H₂O₂ acute toxicity. No relationship between phenolic composition and cytotoxicity of the extracts was found. Rather, a significant increase in glutathione was observed in cells exposed to kale extract, which contained the highest amount and variety of flavonoids. It can be concluded that although flavonoids-rich extracts have the ability to increase cellular antioxidant defenses, the use of extracts of kale and P. brassicae materials by pharmaceutical or food industries, may constitute an insult to health, especially to debilitated individuals, if high doses are consumed.

2012Journal article

Open access