Browsing by Author "Oliveira, Andreia P."
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- Characterization of Ficus carica L. cultivars by DNA and secondary metabolites analysis: Is genetic diversity reflected in the chemical composition?Publication . Oliveira, Andreia P.; Baptista, Paula; Andrade, Paula B.; Martins, Fátima; Pereira, J.A.; Silva, Branca M.; Valentão, PatríciaFicus carica L. is one of the first plants cultivated by humans, having a great economic impact in many countries, the fruit being an important constituent of the Mediterranean diet. Plants' metabolome may be influenced by their genetic diversity, environmental factors and their interaction. Thus, in this study we explored the chemical and morphological profiles and the DNA of five Portuguese F. carica cultivars, to try to establish a correlation between genetics and metabolome. Morphological and molecular markers of these cultivars were assessed for the first time. Besides the observed morphological differences, the rbcL chloroplastic DNA region allowed a better clustering of the cultivars and was more successful in the identification of the species; as so, it could be helpful for authenticity purposes. Phenolic compounds, sterols and triterpenes profiles were determined by HPLC/DAD, the last revealing to be less variable among cultivars, once only a significant difference in the betulol content of “Pingo de Mel” samples was observed. For almost all the accessions studied, no correlation between genetic diversity and composition was observed.
- Chemical assessment and in vitro antioxidant capacity of Ficus carica latexPublication . Oliveira, Andreia P.; Silva, Luís R.; Ferreres, Frederico; Pinho, P. Guedes de; Valentão, Patrícia; Silva, Branca M.; Pereira, J.A.; Andrade, Paula B.Ficus species possess latex-like material within their vasculatures, affording protection and selfhealing from physical attacks. In this work, metabolite profiling was performed on Ficus carica latex. Volatiles profile was determined by HS-SPME/GC-IT-MS, with 34 compounds being identified, distributed by distinct chemical classes: 5 aldehydes, 7 alcohols, 1 ketone, 9 monoterpenes, 9 sesquiterpenes and 3 other compounds. Sesquiterpenes constituted the most abundant class in latex (ca. 91% of total identified compounds). Organic acids composition was also characterized, by HPLC-UV, and oxalic, citric, malic, quinic, shikimic and fumaric acids were determined. Malic and shikimic acids were present in higher amounts (ca. 26%, each). The antioxidant potential of this material was checked by distinct in vitro chemical assays. A concentration-dependent activity was noticed against DPPH, nitric oxide and superoxide radicals. Additionally, acetylcholinesterase inhibitory capacity was evaluated, but a weak effect was found.
- Corantes naturais de origem vegetal aplicados no setor da pastelariaPublication . Reis, Filipa S.; Dias, Maria Inês; Heleno, Sandrina A.; Rodrigues, Paula; Barreira, João C.M.; Oliveira, Andreia P.; Barros, Lillian; Ferreira, Isabel C.F.R.Nos últimos anos o consumidor tem estado mais atento aos ingredientes que são adicionados aos produtos que ingere e tem vindo a optar por alimentos contendo aditivos naturais em alternativa aos artificiais [1,2]. Este trabalho apresenta os resultados obtidos na incorporação de corantes naturais obtidos de diferentes fontes vegetais num produto de pastelaria, ao longo de 6 meses. Os corantes foram obtidos a partir de beterraba, amora, cereja, curcumina e anato. Depois de incorporar os corantes no produto de pastelaria, estas amostras foram divididas em sets de forma a avaliar os seguintes parâmetros: cor, pH, valor nutricional e carga microbiana ao longo do tempo. Os valores obtidos foram comparados com amostras controlo (sem adição de corante) e amostras incorporadas com o corante artificial correspondente, utilizado normalmente pela empresa TecPan. As amostras foram armazenadas expostas e ao abrigo da luz, e os resultados foram comparados. O valor nutricional das amostras, assim como a carga microbiana permaneceram praticamente inalterados ao longo do tempo. Nos produtos incorporados com corantes vermelhos, a beterraba conferiu valores de pH mais elevados. Relativamente aos parâmetros de cor, os produtos sem adição de corantes apresentaram os valores de L* mais elevados, e os valores mais baixos de a*. Quanto ao parâmetro b*, os valores mais elevados foram registados nas amostras incorporadas com beterraba ou, no caso das amostras armazenadas no escuro, na amostra controlo. Quanto à adição de curcumina (amarelo), esta induziu valores de a* mais elevados e de b* mais baixos, comparativamente com o corante artificial correspondente. Aos 6 meses registam-se os valores de pH mínimos, sendo que os valores de L* e b* tendem a diminuir ligeiramente a partir do 4º e 5º mês, em todas as amostras. Nas amostras incorporadas com anato (gama dos laranjas), este induziu os valores de L* mais baixos e os mais elevados de b*. Ao fim dos 6 meses registam-se os valores de pH mais baixos em todas as amostras. No geral, o trabalho desenvolvido ao longo de 6 meses mostra-nos que o corante adicionado teve maior efeito nos parâmetros de pH e cor, revelando possíveis alternativas para o mercado dos corantes naturais.
- Determination of low molecular weight volatiles in Ficus carica using HS-SPME and GC/FIDPublication . Oliveira, Andreia P.; Silva, Luís R.; Andrade, Paula B.; Valentão, Patrícia; Silva, Branca M.; Pereira, J.A.; Pinho, P. Guedes deFicus carica L. is one of the earliest cultivated fruit trees, having an important consumption in Mediterranean countries. In this work, the volatile compound profiles of two characteristic Portuguese white varieties (‘‘Pingo de Mel” and ‘‘Branca Tradicional”) was determined by HS-SPME and GC/FID. Leaves, pulps and peels, submitted to freezing and lyophilisation treatments, were analysed. The two varieties presented a similar profile composed of eight volatile compounds: acetaldehyde, ethyl acetate, methanol, ethanol, hexanal, limonene, (E)-2-hexenal and octanal. The total volatile content was different among the vegetal materials, following the order leaves > peels > pulps. Methanol and ethanol are the major compounds in all samples. The developed procedure revealed to be rapid, sensitive, reproducible and accurate. The detection limit values were low, and the method precise. The recovery values for acetaldehyde, ethyl acetate, methanol and ethanol were generally high, suggesting that it will be most suitable for compounds with low molecular weight. Due to its rapidity and low cost, this technique can be useful in the quality control of fig fruit and leaves.
- Ficus carica L.: metabolic and biological screening.Publication . Oliveira, Andreia P.; Valentão, Patrícia; Pereira, J.A.; Silva, Branca M.; Tavares, Fernando; Andrade, Paula B.Ficus carica L. is one of the earliest cultivated fruit trees. In this work, metabolite profiling was performed on the leaves, pulps and peels of two Portuguese white varieties of F. carica (Pingo de Mel and Branca Tradicional). Phenolics and organic acids profiles were determined by HPLC/DAD and HPLC/UV, respectively. All samples presented a similar phenolic profile composed by 3-O- and 5-O-caffeoylquinic acids, ferulic acid, quercetin-3-O-glucoside, quercetin-3-O-rutinoside, psoralen and bergapten. 3-O-Caffeoylquinic acid and quercetin-3-O-glucoside are described for the first time in this species. Leaves’ organic acids profile presented oxalic, citric, malic, quinic, shikimic and fumaric acids, while in pulps and peels quinic acid was absent. The antioxidant potential of the different plant parts was checked. All materials exhibited activity against DPPH and nitric oxide radicals in a concentration-dependent way. However, only the leaves presented capacity to scavenge superoxide radical. Leaves were always the most effective part, which seems to be related with phenolics compounds. Additionally, acetylcholinesterase inhibitory capacity was evaluated, but no effect was observed. Antimicrobial potential was also assessed against several bacterial species, although no activity was noticed. This is the first study comparing the chemical composition and biological potential of F. carica pulps, peels and leaves.
- Free amino acids of Tronchuda Cabbage (Brassica oleracea L. Var. costata DC): influence of leaf position (internal or external) and collection timePublication . Oliveira, Andreia P.; Pereira, David M.; Andrade, Paula B.; Valentão, Patrícia; Sousa, Carla; Pereira, J.A.; Bento, Albino; Rodrigues, M.A.; Seabra, Rosa M.; Silva, Branca M.The free amino acid profile of 18 samples of tronchuda cabbage (Brassica oleracea L. var. costata DC) leaves, harvested at three different months, was determined by HPLC/UV−vis. The tronchuda cabbage leaves total free amino acid content varied from 3.3 to 14.4 g/kg fresh weight. Generally, arginine was the major compound, followed by proline, threonine, glutamine, cysteine, and glutamic acid. This study indicates that free amino acids are not similarly distributed: in external leaves, proline and arginine were the major free amino acids, while in internal ones, arginine was the main free amino acid, followed by threonine, glutamine, and cysteine. Significant differences were observed for valine, proline, arginine, leucine, cysteine, lysine, histidine, and tyrosine contents. The levels of some free amino acids were significantly affected by the collection period. In external leaves, this occurred with glutamic acid, serine, valine, leucine, cysteine, and ornithine contents, while in internal leaves, it occurred with aspartic acid, arginine, and total contents.
- Further insights into the latex metabolite profile of Ficus caricaPublication . Oliveira, Andreia P.; Silva, Luís R.; Andrade, Paula B.; Valentão, Patrícia; Silva, Branca M.; Gonçalves, Rui; Pereira, J.A.; Pinho, P. Guedes deLatex is a sticky emulsion that exudes upon damage from specialized canals from several plants. It contains several biologically active compounds, such as phytosterols, fatty acids, and amino acids. In plants, these compounds are involved in the interaction between plants, insects, and the environment. Despite its chemical, biological, and ecological importance, Ficus carica latex is still poorly studied. To improve the knowledge on the metabolite profile of this matrix, a targeted metabolite analysis was performed in a representative sample from F. carica latex. Seven phytosterols were determined by gas chromatography-ion trap mass spectrometry (GC-ITMS) and high-performance liquid chromatography coupled to diode array detection (HPLC-DAD), with β-sitosterol and lupeol being the compounds present in higher concentrations (ca. 54 and 14%, respectively). A total of 18 fatty acids were characterized by GC-ITMS, being essentially represented by saturated fatty acids (ca. 86.4% of total fatty acids). A total of 13 free amino acids were also identified by high-performance liquid chromatography coupled to ultraviolet-visible spectroscopy (HPLC/UV-vis), and cysteine and tyrosine were the major ones (ca. 38.7 and 31.4%, respectively). In humans, phytosterols and some polyunsaturated fatty acids, such as linoleic acid, are known for their anticarcinogenic properties. With regard to amino acids, some of them, such as glycine, are neurotransmitters. Our results reveal the presence of a wide diversity of compounds, from distinct classes, in F. carica latex, possessing various potential pharmacological activities; thus, its biological potential appears to be worth further exploring.
- Natural colouring agents obtained from different plant sources applied to the pastry sectorPublication . Reis, Filipa S.; Dias, Maria Inês; Antonio, Amilcar L.; Barreira, João C.M.; Oliveira, Andreia P.; Barros, Lillian; Ferreira, Isabel C.F.R.Given that some intolerance and allergic reactions have been associated with the consumption of artificial additives, in recent decades consumers have been choosing to ingest food containing natural alternatives [1,2]. The present work presents some preliminary results regarding the incorporation of natural colorants in products of the pastry industry. The juices of different natural matrices namely beet, blackberry and cherry were incorporated into a pastry product (at TecPan Lda.). The samples were divided into small sets, to evaluate the nutritional value, the microbial load and the parameters of color and pH over time. Here, we present the results of the first three months of storage of the pastry products. The values obtained were compared with control samples (without any natural/artificial colorant) and with products incorporated with an artificial colorant used by the company. Moreover, the products were stored, exposed and protected from light, in order to verify the stability of the additives, and the results were compared. The nutritional value of the samples remained practically unchanged over time, and no changes were observed regarding the microbial load of the samples. However, some variations were observed in the pH and color values. The products prepared with berry juices tended to present the highest pH values. Regarding the color parameter, products prepared without any coloring agent showed the highest L* values, whilst those prepared with the artificial colorant were less bright. In what regards a*, as expected, control products presented the lowest value. Concerning b*, the minimum values were registered in products prepared with the artificial colorant, and the maximum ones observed in control samples. Overall, the storage time did not induce any significant change in any case, and the results obtained from stored samples protected from light and exposed to light were very similar.
- Organic acids composition of Cydonia oblonga Miller leafPublication . Oliveira, Andreia P.; Pereira, J.A.; Andrade, Paula B.; Valentão, Patrícia; Seabra, Rosa M.; Silva, Branca M.Organic acid profiles of 36 Cydonia oblonga Miller leaf samples, from three different geographical origins of northern (Bragança and Carrazeda de Ansiães) and central Portugal (Covilhã), harvested in three collection months (June, August and October of 2006), were determined by HPLC/UV (214 nm). Quince leaves presented a common organic acid profile, composed of six constituents: oxalic, citric, malic, quinic, shikimic and fumaric acids. C. oblonga leaves total organic acid content varied from 1.6 to 25.8 g/kg dry matter (mean value of 10.5 g/kg dry matter). Quinic acid was the major compound (72.2%), followed by citric acid (13.6%). Significant differences were found in malic and quinic acids relative abundances and total organic acid contents according to collection time, which indicates a possible use of these compounds as maturity markers. Between June and August seems to be the best period to harvest quince leaves for preparation of decoctions or infusions, since organic acids total content is higher in this season.
- Phenolic composition of Cydonia oblonga Miller leaf.Publication . Silva, Branca M.; Oliveira, Andreia P.; Pereira, J.A.; Valentão, Patrícia; Seabra, Rosa M.; Andrade, Paula B.Phenolic profile of 36 Cydonia oblonga Miller leaf samples, from 3 different geographical origins of Portugal, harvested in 3 collection months, was determined by HPLC/DAD. Quince leaf presented a common profile composed by 9 constituents: 3-0-, 4-0- and 5-0-caffeoylquinic acids, 3,5-0-dicaffeoylquinic acid, quercetin-3-0 galactoside, quercetin-3-0-rutinoside, kaempferol-3-0-glycoside, kaempferol-3-0-g1ucoside and kaempferol-3-0-rutinoside. C. oblonga leaf total content varied from 4.9 to 16.5 g/kg of dry matter, indicating that this leaf can be used as a good and cheap source of bioactive constituents. 5-0-caffeoylquinic acid was the major phenolic compound (36.2%). Significantly differences were found in 3-0-caffeoylquinic and 3,5-0-dicaffeoylquinic acids contents, according to geographical provenience and harvesting month.