Browsing by Author "Petropoulos, Spyridon Α."
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- Agri-food surplus, waste and loss as sustainable biobased ingredients: a reviewPublication . Rodrigues, Joana P.B.; Liberal, Ângela; Petropoulos, Spyridon Α.; Ferreira, Isabel C.F.R.; Oliveira, Beatriz; Fernandes, Ângela; Barros, LillianEnsuring a sustainable supply of food for the world’s fast growing population is a major challenge in today’s economy, as modern lifestyle and increasing consumer concern with maintaining a balanced and nutritious diet is an important challenge for the agricultural sector worldwide. This market niche for healthier products, especially fruits and vegetables, has increased their production, consequently resulting in increased amounts of agri-food surplus, waste, and loss (SWL) generated during crop production, transportation, storage, and processing. Although many of these materials are not utilized, negatively affecting the environmental, economic, and social segments, they are a rich source of valuable compounds that could be used for different purposes, thus preventing the losses of natural resources and boosting a circular economy. This review aimed to give insights on the efficient management of agri-food SWL, considering conventional and emerging recovery and reuse techniques. Particularly, we explored and summarized the chemical composition of three worldwide cultivated and consumed vegetables (carrots, broccoli and lettuce) and evaluate the potential of their residues as a sustainable alternative for extracting value-added ingredients for the development of new biodynamic products
- Alternative sources of n-3 fatty acids from plant originPublication . Petropoulos, Spyridon Α.; Vaz, Josiana A.; Fernandes, Ângela; Karkanis, Anestis; Barros, Lillian; Ferreira, Isabel C.F.R.N-3 fatty acids are considered essential for human health, since they are associated with beneficial effects against many diseases of modern world. The most common dietary sources of n-3 fatty acids are fishes such as salmon and sardines among others, which are also incriminated with high heavy metals content. Flax or linseed is the most widely known plant source of n-3 fatty acids and is the main ingredient of food supplements. The aim of the present study was to evaluate seeds and seed oils of purslane as alternative sources of n-3 fatty acids. For this purpose, purslane seeds, oils from seeds extracted with three methods (screw press methods with or without a cooler), and seed presscakes were evaluated in terms of fatty acids composition and cytotoxicity. For comparison purposes, three commercial linseed oils, one cucurbit oil and one luffa oil were also analyzed in terms of fatty acids composition and cytotoxicity against various human tumor cell lines. The results of the study showed that linseed oils were abundant in α-linolenic acid (65.62%-71-90%), followed by linoleic and oleic acids (12.87%-17.98% and 6.43%-7.09%, respectively), while n6/n3 and PUFA/SFA ratios were lower than 4.0 and higher than 0.45, respectively. In contrast, cucurbit and luffa oils have very low amount of α-linolenic acid, since they contained mostly linoleic, oleic, palmitic and stearic acid, which resulted in very high values of n6/n3 ratios. The main detected fatty acids in purslane seed oils were α-linolenic and linoleic in amounts that depended on the extraction method. Seeds and seed presscakes also contained high amounts of α-linolenic acid and linoleic acids; however, extraction method affected fatty acids composition and values of n6/n3 and PUFA/SFA ratios. Finally, luffa oil showed the highest cytotoxicity against HeLa and NCI-H460 tumor cell lines, followed by cucurbit and one of the tested linseed oils. In conclusion, purslane seeds and seed oils could be considered as alternative n-3 fatty acids, while they have a balanced fatty acids composition and show moderate cytotoxicity against specific tumor cell lines.
- Análise do perfil nutricional de partes comestíveis da Portulaca oleracea L. produzida pela técnica de rotação de culturasPublication . Paschoalinotto, B.H.; Prieto Lage, Miguel A.; Polyzos, Nikolaos; Compocholi, Maria; Petropoulos, Spyridon Α.; Ferreira, Isabel C.F.R.; Dias, Maria Inês; Barros, LillianPortu/aca o/eracea L. (beldroega) é uma planta silvestre comestível com reconhecidas propriedades medicinais. As suas folhas e caules são popularmente consumidos preparadas como sumos, mas também em cru ou cozidas em saladas. Recentemente a beldroega foi descrita como alimento funcional, devido ao seu alto valor nutricional, o que fez despertar um grande interesse na sua produção em cultivo controlado, especialmente quando se considera a sua grande adaptabilidade como espécie a várias condições adversaslul. Considerando a importância de explorar novas fontes sustentáveis de nutrientes e compostos bioativos alinhado com a manutenção da qualidade do solo, a aplicação da técnica agrícola de rotação de culturas tem vários benefícios agronómicos, que estão já bem documentadosl3l. Com vista a obter beldroegas com maior valor nutricional e terapêutico, foi aplicada este tipo de técnica na sua produção em três pontos experimentais com rotação com uma cultura de feijão. O conteúdo em proteína bruta, lípidos totais, fibras dietéticas totais, cinzas e hidratos de carbono (por diferença) das folhas e caules foram avaliados por métodos AOAC. A energia foi calculada de acordo com a equação: energia (kcal por 100 g) = 9 x (g gordura) + 4 x (g proteína + g hidratos de carbono) + 2 x (g fibras dietéticas totais). Nos lípidos totais e proteína bruta foram observadas diferenças nutricionais significativas entre as parcelas experimentais, bem como nas folhas e caules da beldroega, sendo que as folhas revelaram as maiores quantidades. O teor de cinzas não variou entre folhas e caules da mesma parcela experimental, mas foi novamente nas folhas que se observou um maior conteúdo em fibras dietéticas totais e maior valor energético. A produção de beldroega em solo continua a ser bastante promissora, no entanto, a produção com rotação com uma cultura de feijão revelou maiores teores de fibra brutal4l. Com os resultados preliminares obtidos, o uso de técnicas de rotação de culturas permite a obtenção de beldroegas com alto valor nutricional, para além de aumentar a sua disponibilidade na indústria e, por conseguinte, para o consumidor final.
- Anthocyanin-rich extracts from purple and red potatoes as natural colourants: Bioactive properties, application in a soft drink formulation and sensory analysisPublication . Sampaio, Shirley L.; Lonchamp, Julien; Dias, Maria Inês; Liddle, Catriona; Petropoulos, Spyridon Α.; Glamočlija, Jasmina; Alexopoulos, Alexios; Santos-Buelga, Celestino; Ferreira, Isabel C.F.R.; Barros, LillianAqueous extracts from seven coloured potato varieties (three red-fleshed, three-purple fleshed, and one marble-fleshed) were studied for their anthocyanin content, in vitro biological activities, colouring properties and their potential application in the food industry. Acylated glycosides or pelargonidin and petunidin aglycones were identified as the main anthocyanin forms in the red and purple varieties, respectively. The total anthocyanin content among varieties ranged from 478.3 to 886.2 mg/100 g extract. All the extracts presented in vitro antioxidant, antibacterial and antifungal activities, whereas no toxic effects were detected. Finally, two selected extracts were tested as colourants in a soft drink formulation and presented suitable sensory profiles as well as high colour stability during a 30-day shelf-life when compared with the commercial colourant E163. Therefore, the tested extracts could be used as natural food colourants and considered for substituting the existing synthetic colouring agents.
- Antimicrobial and antioxidant properties of various Greek garlic genotypesPublication . Petropoulos, Spyridon Α.; Fernandes, Ângela; Barros, Lillian; Ćirić, Ana; Soković, Marina; Ferreira, Isabel C.F.R.Recent studies show a significant variation in antioxidant and antimicrobial properties between the various garlic genotypes mostly due to differences in chemical composition and bioactive compounds content. The aim of the present study was to evaluate antioxidant properties and antimicrobial activity of garlics collected from the main cultivation areas of Greece, as well as to correlate this activity with their total phenolics content. Genotype G5 showed the highest total phenolics content, which was significantly correlated with the lowest EC 50 values for all the tested antioxidant activity assays. Antimicrobial activity was significant, especially against the bacteria Proteus mirabilis and Antibiotic resistant Escherichia coli. In conclusion, significant variation was observed between the studied garlic genotypes, indicating the importance of both growing conditions and genotype on bioactive properties of dry garlic bulbs. This variation could be further exploited in breeding programs in order to select elite genotypes with increased bioactive properties.
- Antimicrobial properties, cytotoxic effects, and fatty acids composition of vegetable oils from purslane, linseed, luffa, and pumpkin seedsPublication . Petropoulos, Spyridon Α.; Fernandes, Ângela; Calhelha, Ricardo C.; Rouphael, Youssef; Petrović, Jovana; Soković, Marina; Ferreira, Isabel C.F.R.; Barros, LillianIn the present study, the antimicrobial and cytotoxic activities, as well as the fatty acids composition in vegetable seed oils from linseed, purslane, luffa, and pumpkin were evaluated. For this purpose, two linseed oils and one luffa oil were commercially obtained, while purslane and pumpkin oils were obtained from own cultivated seeds. The results showed a variable fatty acids composition among the tested oils, with α-linolenic, linoleic, oleic, palmitic, and stearic acid being the most abundant compounds. In regards to particular oils, linseed oils were a rich source of α-linolenic acid, luffa and pumpkin oil were abundant in linoleic acid, while purslane oil presented a balanced composition with an almost similar amount of both fatty acids. Luffa oil was the most effective against two of the tested cancer cell lines, namely HeLa (cervical carcinoma) and NCI-H460 (non-small cell lung cancer), while it also showed moderate toxicity against non-tumor cells (PLP2 cell line). Regarding the antibacterial activity, linseed oil 3 and pumpkin oil showed the highest activity against most of the tested bacteria (especially against Enterobacter cloacae and Escherichia coli) with MIC and MBC values similar to the used positive controls (E211 and E224). All the tested oils showed significant antifungal activities, especially luffa and pumpkin oil, and for most of the tested fungi they were more effective than the positive controls, as for example in the case of Aspergillus versicolor, A. niger, and Penicillium verrucosum var. cyclopium. In conclusion, the results of our study showed promising antimicrobial and cytotoxic properties for the studied seed oils which could be partly attributed to their fatty acids composition, especially the long-chain ones with 12–18 carbons.
- Antioxidant activity and chemical composition of Cichorium spinosum L. in relation to nitrogen ratePublication . Petropoulos, Spyridon Α.; Fernandes, Ângela; Karkanis, Anestis; Ntatsi, Georgia; Barros, Lillian; Ferreira, Isabel C.F.R.In the present study, the effect of nitrogen (N) application rate on phenolic compounds content and antioxidant activity of Cichorium spinosum L. leaves was examined. Seeds were sown in seed trays containing peat and young seedlings were transplanted in 2-L plastic pots containing soil. Four nitrogen rates were applied, namely: a) control (no added N), b) 200 mg L-1 of total N, c) 400 mg L-1 of total N, and d) 600 mg L-1 of total N. Plants were harvested when rosettes reached marketable size. The results showed that the most abundant phenolic compounds of leaves extracts were chlorogenic acid, chicoric acid and kaempferol-3-O-glucuronide, while increasing nitrogen rates resulted in a significant decrease of the main phenolic compounds content. Similarly, the application of 600 mg L-1 of total nitrogen resulted in significant decrease of antioxidant potency of leaf extracts comparing to control, regardless of the performed assay, whereas for all the assays except for DPPH the application of 200 mg L-1 showed the best antioxidant properties. In conclusion, although the application of high nitrogen rates is tempting in order to achieve higher yields, rates higher than 200 mg L-1 are not recommended for C. spinosum cultivation, since a significant decrease of the bioactive compounds is observed that could compromise the quality of the final product.
- Avaliação da influência da adubação via solução nutritiva no perfil nutricional de Scolymus hispanicus L.Publication . Paschoalinotto, B.H.; Prieto Lage, Miguel A.; Compocholi, Maria; Polyzos, Nikolaos; Petropoulos, Spyridon Α.; Ferreira, Isabel C.F.R.; Dias, Maria Inês; Barros, LillianIntrodução - Scolymus hispanicus L. (cardo dourado) é uma planta silvestre comestível da região do Mediterrâneo, tradicionalmente consumida pelos seus efeitos benéficos para a saúde, o que tem vindo a despertar grande interesse para a produção controlada1. Objetivos e metodologia - Avaliação do efeito da adubação, usando soluções nutritivas com diferentes rácios de azoto (N), fósforo (P) e potássio (K), no perfil nutricional (métodos AOAC) das folhas de S. Hispanicus, bem como no conteúdo de minerais (espectrofotometria de absorção atómica). Resultados - A amostra controlo (sem adubação) apresentou os maiores teores na maioria dos parâmetros estudados, com exceção do teor de fibras, hidratos de carbono e energia. As amostras adubadas com 300 mg/kg de azoto apresentaram os menores valores em relação aos teores de gordura, proteína bruta e fibra. A amostra adubada com 300:100:100 mg/kg de N:P:K apresentou a maior quantidade de sódio, cálcio e magnésio e o menor teor de potássio e zinco; enquanto que, a amostra controlo apresentou os maiores teores de potássio, ferro e zinco. Conclusão - Verificou-se que a concentração de N:P:K pode afetar diretamente o valor nutricional e o conteúdo mineral da planta em estudo, sendo que altas concentrações de azoto apresentaram um impacto negativo no conteúdo proteico, indicando a baixa resposta da planta para aumentar as taxas de adubação com azoto.
- Avaliação do potencial das folhas da Cynara carcunculus L. como ingrediente funcionalPublication . Mandim, Filipa; Petropoulos, Spyridon Α.; Pinela, José; Dias, Maria Inês; Santos-Buelga, Celestino; Barros, LillianCynara cardunculus L., usualmente denominada por cardo, é uma espécie herbácea nativa dos países da bacia do Mediterrâneo. Esta espécie exibe um diversificado número de aplicações industriais1. É utilizada na medicina tradicional devido às suas propriedades benéficas para a saúde. O cardo é também considerado um alimento funcional devido à sua rica composição em compostos com propriedades funcionais (como por exemplo, ácidos fenólicos, flavonoides, fibra, inulina)2,3. No presente estudo, a influencia do estado de maturação nas propriedades bioativas das folhas de cardo foi analisada.
- Biactive properties of Greek garlic genotypesPublication . Fernandes, Ângela; Petropoulos, Spyridon Α.; Barros, Lillian; Ćirić, Ana; Soković, Marina; Ferreira, Isabel C.F.R.Garlic (Allium sativum L.) is one of the most economically important species of the Allium genus throughout the world. One of the major beneficial effects of garlic is related with antioxidant properties which have been associated with many therapeutic effects, including cancer prevention, antithrombotic effects, cardiovascular protection and anti-aging effects. The aim of the present study was to determine the bioactive properties from various Greek garlics in order to determine the variability in their antimicrobial and antioxidant properties, as well as to compare them with commercial cultivars. The collected samples included: one local garlic cultivar from Evros “Nea Vissa” (samples G1 and G2); one sample of a local landrace and one sample of Chinese origin cultivated in Neapoli; (samples G3 and G4, respectively); one sample from Euboea Prefecture of Chinese origin (G5); one sample of local cultivar of “Platykampos”, one commercial sample of Chinese origin and one sample of commercial cultivar Gardos, all cultivated in Magnissia Perfecture (G6-G8, respectively), and three samples from Arcadia Prefecture of local cultivar of “Tripoli” (G9-11). The antioxidant activity was evaluated by DPPH radical-scavenging activity, reducing power, inhibition of beta-carotene bleaching and inhibition of lipid peroxidation. The antimicrobial activity was evaluated against four Gram positive bacteria, six Gram negative bacteria and two fungi, using the microdilution method, in order to obtain the minimal growth inhibititory concentrations and minimal bactericidal/funcicidal concentrations. Genotype G5 showed the lowest EC50 values for all the tested antioxidant activity assays. The antimicrobial activity was significant, especially against the bacteria P. mirabilis and antibiotic resistant E. coli. Significant variation was observed between the studied garlic genotypes, indicating the importance of both growing conditions and genotype on the bioactive properties of dry garlic. This variation could be further exploited in breeding programs in order to select elite genotypes with increased bioactive properties.