CIMO - Resumos em Proceedings Não Indexados à WoS/Scopus
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Browsing CIMO - Resumos em Proceedings Não Indexados à WoS/Scopus by Author "Achour, Lotfi"
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- Arbutus unedo L. and Ocinum basilicum L. as sources of natural ingredients for bread functionalizationPublication . Sallawi, Takwa; Caleja, Cristina; Achour, Lotfi; Barros, Lillian; Ferreira, Isabel C.F.R.The overwhelming growth of the world population is causing direct consequences on food demands, which has forced the food industry to apply synthetic additives in order to meet the needs of the consumer and ensuring the global quality of the food products including aspect, texture and flavor. However, due to the publication of some studies describing adverse effects associated with these synthetic additives, the natural ones have been gaining increasing interest. Arbutus unedo L. (strawberry tree) fruits and Ocimum basilicum L. (basil) leaves, are important sources of bioactive natural molecules, especially phenolic compounds, including flavan-3- ols and phenolic acids, respectively . The aim of this work was to demonstrate the antioxidant potential (free radical scavenging effect, reducing power and inhibition of lipid peroxidation) and the absence of toxicity (porcine liver primary cells) of ethanol extracts, obtained from the previously mentioned plants by using optimal conditions. Subsequently, the extracts were incorporated as natural ingredients in loaf bread samples, with two objectives: to functionalize loaf bread, introducing bioactive properties; and as natural ingredients with preservation capacity. Five groups of loaf bread samples were prepared: i) control (without natural or synthetic additives); ii) loaf bread incorporated with strawberry tree extract; iii) loaf bread incorporated with basil extract; iv) loaf bread incorporated with ascorbic acid- E300 (natural additive); and v) loaf bread incorporated with potassium sorbate- E202 (synthetic additive). Both extracts (strawberry tree fruits and basil leaves) presented antioxidant activity (EC50 values lower the 595 and 351 μg/mL, respectively), without toxicity up to the maximal tested dose, and the main compounds present were (+)-catechin and rosmarinic acid, respectively. The introduction of both natural and synthetic additives in loaf bread when compared to the control sample, did not cause significant changes, neither in pH values, nor in color or any of the evaluated nutritional parameters. The obtained results demonstrate that these extracts could be used in the development of new loaf bread replacing the synthetic preservatives, without interfering with the physical and nutritional characteristics.
- Arbutus unedo L. e Ocimum basilicum L. como conservantes naturais de pãoPublication . Sallawi, Takwa; Caleja, Cristina; Barreira, João C.M.; Soković, Marina; Achour, Lotfi; Barros, Lillian; Ferreira, Isabel C.F.R.Atualmente, existe uma preocupação da indústria alimentar na substituição de aditivos sintéticos por ingredientes naturais. Os extratos naturais obtidos a partir de plantas surgem como possíveis alternativas aos conservantes sintéticos, nomeadamente dos antioxidantes. Neste trabalho, pretendeu-se comprovar a eficácia de extratos ricos em catequina, obtido a partir de frutos de Arbutus unedo L. (medronho) e em ácido rosmarínico obtido a partir de folhas de Ocimum basilicum L. (manjericão), como conservantes naturais de pão, comparando a sua eficácia com aditivos sintéticos normalmente aplicados a produtos de panificação. Após a avaliação das propriedades antioxidantes (valores EC50 do efeito bloqueador de radicais de DPPH = 595 e 351 μg/ mL, para medronho e manjericão, respetivamente) e antimicrobianas (contra 8 bactérias e 8 fungos) e confirmação da ausência de citoxicidade (numa cultura primária de células de fígado), os extratos ricos em (+)-catequina e ácido rosmarínico foram incorporados no pão. O seu efeito foi comparado com o ácido ascórbico (E300), o sorbato de potássio (E202) e com uma amostra controlo (pão sem aditivos) imediatamente após a incorporação e após 3 e 7 dias de armazenamento, à temperatura ambiente e protegidos da luz. Os pães aditivados com os extratos naturais, especialmente de manjericão, apresentaram maior capacidade antioxidante do que os pães com ácido ascórbico e sorbato de potássio, tendo todos mantido as suas propriedades nutricionais. Em geral, os resultados obtidos demonstraram que os extratos podem ser utilizados no desenvolvimento de pão, substituindo os conservantes sintéticos, sem interferir nas características físicas e nutricionais dos produtos finais.
- Chemical characterization of Opuntia sp. by-productsPublication . Chahdoura, Hassiba; Barreira, João C.M.; Barros, Lillian; Santos-Buelga, Celestino; Ferreira, Isabel C.F.R.; Achour, LotfiThe species from the Cactaceae family are important invaders in the Mediterranean. The seeds are usually discarded and proper utilisation of these waste products could lead to an important source of bioactive compounds. The seeds have been described to be rich in health-promoting polyunsaturated fatty acids and may potentially be included in animal and human diets [1]. Moreover, seeds could also be recovered for their high nutritional value, as sources of sugars, tocopherols, dietary fiber and polyphenols instead of being discarded, as it currently occurs. In this study, the composition in soluble sugars, fatty acids, organic acids, tocopherols and phenolic composition were determined in seeds of Opuntia macrorhiza (Engelm.) and Opuntia microdasys (Lehm.). The individual sugars profile was determined by HPLC-RI, fatty acids by GC-FID, organic acids by HPLC-DAD, tocopherols by HPLC-fluorescence and phenolic compounds by HPLC-DAD-ESI/MS. In both cases, the overall concentrations of soluble sugars in seeds were quite lower than those detected in other Opuntia sp. parts. Quinic (0.30 g/100 g dw) and oxalic (0.32 g/100 g dw) acids were the major organic acids detected in O. microdasys and O. macrorhiza, respectively. The fatty acid profiles detected in the seeds of both species were similar, with linoleic acid (C18:2n6) as the major fatty acid (71% in O. microdasys; 74% in O. macrorhiza). γ-Tocopherol was the most abundant tocopherol vitamer in both species (7.4 mg/100 g dw in O. microdasys; 5.8 mg/100 g dw in O. macrorhiza). Regarding the phenolic profile, eight compounds were identified: seven phenolic acid derivatives and one flavonoid, and O. macrorhiza seeds (1016 μg/g extract) revealed a higher concentration than O. microdasys (450 μg/g extract). Feruloyl di-hexoside was the most abundant phenolic acid in both species (225 μg/g extract in O. microdasys and 718 μg/g extract in O. macrorhiza). The seeds of Opuntia sp. presented several bioactive phytochemicals, which may allow considering this botanical part as highly interesting by-products.
- HPLC-DAD-ESI/MS phenolic characterization and biological activity of Equisetum giganteum L.Publication . Jabeur, Inès; Martins, Natália; Barros, Lillian; Calhelha, Ricardo C.; Vaz, Josiana A.; Achour, Lotfi; Santos-Buelga, Celestino; Ferreira, Isabel C.F.R.Naturally-occurring phytochemicals have received a pivotal attention in the last years, due to the increasing evidences of biological activities. Equisetum giganteum L., commonly known as “giant horsetail”, is a native plant from Central and South America, being largely used in dietary supplements as diuretic, hemostatic, antiinflammatory and anti-rheumatic agents [1,2]. The aim of the present study was to evaluate the antioxidant (scavenging effects on 2,2-diphenyl-1-picrylhydrazyl radicals- RSA, reducing power- RP, β-carotene bleaching inhibition- CBI and lipid peroxidation inhibition- LPI), anti-inflammatory (inhibition of NO production in lipopolysaccharidestimulated RAW 264.7 macrophages) and cytotoxic (in a panel of four human tumor cell lines: MCF-7- breast adenocarcinoma, NCI-H460- non-small cell lung cancer, HeLa- cervical carcinoma and HepG2- hepatocellular carcinoma; and in non-tumor porcine liver primary cells- PLP2) properties of E. giganteum, providing a phytochemical characterization of its extract (ethanol/water, 80:20, v/v), by using highperformance liquid chromatography coupled to diode array detection and electrospray ionisation mass spectrometry (HPLC-DAD–ESI/MS). E. giganteum presented fourteen phenolic compounds, two phenolic acids and twelve flavonol glycoside derivatives, mainly kaempferol derivatives, accounting to 81% of the total phenolic content, being kaempferol-O-glucoside-O-rutinoside, the most abundant molecule (7.6 mg/g extract). The extract exhibited antioxidant (EC50 values = 123, 136, 202 and 57.4 μg/mL for RSA, RP, CBI and LPI, respectively), anti-inflammatory (EC50 value = 239 μg/mL) and cytotoxic (GI50 values = 250, 258, 268 and 239 μg/mL for MCF-7, NCI-H460, HeLa and HepG2, respectively) properties, which were positively correlated with its concentration in phenolic compounds. Furthermore, up to 400 μg/mL, it did not revealed toxicity in non-tumor liver cells. Thus, this study highlights the potential of E. giganteum extracts as rich sources of phenolic compounds that can be used in the food, pharmaceutical and cosmetic fields.
- Phenolic profile obtained by HPLC-DAD-ESI/MS and in vitro bioactivities of Equisetum giganteum L. and Tilia platyphyllos Scop.Publication . Jabeur, Inès; Martins, Natália; Barros, Lillian; Calhelha, Ricardo C.; Vaz, Josiana A.; Achour, Lotfi; Santos-Buelga, Celestino; Ferreira, Isabel C.F.R.Medicinal plants are a source of a wide range of bioactive compounds, such as alkaloids, terpenes, steroids and phenolic compounds, which are responsible for multiple biological effects [1, 2]. In the present work, the phenolic composition and bioactive potential of the aqueous and hydroethanolic extracts of Equisetum giganteum L. and Tilia platyphyllos Scop. were evaluated. The phenolic compounds were determined using a Hewlett-Packard 1100 chromatograph, with a diode array detector coupled to a MS detector API 3200 Qtrap through an ESI source and a triple quadrupole-ion trap mass analyser, while the bioactive properties were evaluated in terms of antioxidant, anti-inflammatory, and cytotoxic activities. The hydroethanolic extracts revealed higher amounts of phenolic compounds than infusions, being the concentration of flavonoids (81% of the phenolic composition) remarkably higher than the phenolic acids content (19%), in both species and extracts. T. platyphyllos presented a higher phenolic content (50.4 ± 0.4 mg/g of hydroethanolic extract and 11.65 ± 0.05 mg/g of lyophilized infusion), than E. giganteum (21.7 ± 0.4 mg/g and 4.98 ± 0.03 mg/g, respectively). Moreover, kaempferol- O-glucoside-O-rutinoside was the most abundant flavonoid in E. giganteum extract, while protocatechuic acid and (−)-epicatechin were the most abundant phenolic acid and flavonoid, respectively, in T. platyphyllos extract. Regarding the bioactive assays, both extracts obtained from T. platyphyllos showed the highest potential and none of the extracts showed toxicity in non-tumor liver cells. These biological properties were highly correlated with its content and composition in phenolic compounds. Thus, it would be interesting to evaluate the in vivo efficacy of both plant extracts to unveil the involved modes of action and to establish effective therapeutic doses.
- Phytochemical characterization of Opuntia macrorhiza (Engelm.) and Opuntia microdasys (Lehm.) cladodesPublication . Chahdoura, Hassiba; Barreira, João C.M.; Barros, Lillian; Santos-Buelga, Celestino; Ferreira, Isabel C.F.R.; Achour, LotfiThe genus Opuntia belongs to the Cactaceae family. The cladodes, also known as “nopalitos”, have been widely used, in many countries, for their beneficial effects and phytochemical composition. It is used as a food, as a source of nutrients, and also in folk medicine [1]. In the present work, the cladodes of Opuntia macrorhiza (Engelm.) and Opuntia microdasys (Lehm.) were characterized in terms of free sugars, organic acids, fatty acids, tocopherols and phenolic compounds. The individual sugars’ profile was determined by HPLC-RI, organic acids by HPLC-DAD, fatty acids by GC-FID, and tocopherols by HPLCfluorescence. The phenolic compounds profile was determined by HPLC-DAD-MS/ESI. Despite the phylogenetic proximity and similar geographical origin the samples of O. microdasys and O. macrorhiza showed significant differences in the profiles of sugars, organic acids, fatty acids, tocopherols and phenolic compounds. While, O. microdasys presented higher sugars and tocopherols content, O. macrorhiza revealed higher concentration in organic acids, poly and monounsaturated fatty acids. The cladodes of O. microdasys (10 compounds: 6 phenolic acid derivatives and 4 favonols) revealed a higher amount of phenolic compounds in comparison with O. macrorhiza (7 compounds: 6 phenolic acid derivatives and 1 favonol); only four of the identified compounds were detected simultaneously in both species. Piscidic acid (3400±236 μg/g of extract) and eucomic acid (1688±26 μg/g of extract) were the main phenolic compounds in O. macrorhiza, while isorhamnetin-O-(rhamnosyl)-rutinoside was the most abundant in O. microdasys (2507±73 μg/g of extract). Hence, the elucidation of the most abundant compounds might constitute useful information to select the best species regarding specific applications of these natural extracts.