Percorrer por autor "Polyzos, Nikolaos"
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- 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.
- 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.
- Bioactive properties and phenolic compound profiles of turnip-rooted, plain-leafed and curly-leafed parsley cultivarsPublication . Liberal, Ângela; Fernandes, Ângela; Polyzos, Nikolaos; Petropoulos, Spyridon Α.; Dias, Maria Inês; Pinela, José; Petrović, Jovana; Soković, Marina; Ferreira, Isabel C.F.R.; Barros, LillianPetroselinum crispum Mill., Fuss., is a culinary vegetable used as an aromatic herb that garnishes and flavours a great variety of dishes. In the present study, the chemical profiles and bioactivities of leaf samples from 25 cultivars (three types: plain- and curly-leafed and turnip-rooted) from this species were assessed. Seven phenolic compounds were identified in all the varieties, including apigenin and kaempherol derivates. Apigenin-O-pentoside-O-hexoside was the major compound in all the tested parsley types (20, 22 and 13 mg/g of extract, respectively) and responsible for its excellent antioxidant activity, also investigated in this study. Antimicrobial activities were also explored, and the results revealed a good bioactivity against specific tested pathogens, such as bacteria and fungi. In conclusion, the leaves of all the types of P. crispum are a good source of natural bioactive compounds that confer health benefits, and thus, they should be part of a balanced and diversified diet.
- Biochemical Composition of Pumpkin Seeds and Seed By-ProductsPublication . Polyzos, Nikolaos; Fernandes, Ângela; Calhelha, Ricardo C.; Petrović, Jovana; Soković, Marina; Ferreira, Isabel C.F.R.; Barros, Lillian; Petropoulos, Spyridon Α.The goal of the current work was to assess the nutritional profile and phytochemical properties of cucurbit (Cucurbita maxima L.) seeds, seed oils and oil extraction by-products (e.g., seed-cakes). Our results suggest a high nutritional value for both cucurbit seeds and cucurbit cake, while γ-tocopherol was the richest compound, with traces of α, β and δ-tocopherol compounds also detected. Regarding the free sugars composition, there were recorded significant statistical differences between seeds and cucurbit seed-cake, although sucrose content was the highest for both matrices (1.97 and 2.9 g/100 g dw, respectively) followed by trehalose (0.26 and 0.25 g/100 g dw, respectively), fructose (0.20 and 0.34 g/100 g dw, respectively) and glucose (0.21 and 0.19 g/100 g dw, respectively). In terms of organic acids, oxalic was the only compound detected in seed cake (0.006 g/100 g dw), while in seeds only traces of oxalic and malic acid were detected. In relation to fatty acid composition, linolenic acid was the most abundant compound in both seeds and seed-cake (43.9% and 41.5%, respectively), while oleic acid (37.0% and 36.3%, respectively), palmitic acid (12.2% and 14.0%, respectively) and stearic acid (4.83% and 5.46%, respectively) were detected in lesser amounts. Moreover, polyunsaturated fatty acids (PUFA) were the major fatty acids class (44.5% and 42.3% in seeds and seed cake, respectively) compared to monounsaturated fatty acids (MUFA; 37.4% and 36.7% in seeds and seed cake, respectively) and saturated fatty acids (SFA; 18.1% and 21.0% in seeds and seed cake, respectively) which were detected in lower amounts. Furthermore, the tested extracts did not present any cytotoxic or hepatoxic activity at the maximum tested concentration (GI50 > 400 μg/mL), while seed oils presented satisfactory antimicrobial properties with inhibitory activity against the studied bacterial strains and fungi. Our findings provide valuable knowledge regarding the exploitation of pumpkin seeds and seed by-products as valuable natural sources of nutrients and phytochemicals in the food industry sector within the context of a circular economy.
- Chemical composition and bioactive properties of pumpkin seeds and seed cakesPublication . Polyzos, Nikolaos; Fernandes, Ângela; Chaski, Christina; Petropoulos, Spyridon Α.; Ferreira, Isabel C.F.R.; Barros, LillianPumpkin, (Cucurbita pepo L.) is one of the most important vegetables of the Cucurbitaceae family which is widely used for its edible fleshy fruit, especially fruit pulp. However, other fruit parts such as seeds are a good source of phytochemical and usually consumed in raw or processed form. ln the present work, the chemical composition and bioactive properties of pumpkin seeds and seed cakes were evaluated. Plants from local landrace ''Nychaki" were cultivated at the experimental farm of the University of Thessaly during the summer-autumn growing period of2020 and fruit were collected at marketable maturity. Seeds were removed from 15 randomly selected after cutting each :fruit at the equatorial axis. Then seeds were air-dried at room temperature and pressed with a cold-press to obtain the seed oils and seed cakes, while whole air-dried seeds were ground to fine powder. The ground seeds were rich in fat and proteins (42.7 g/100 g dw and 37.7 g/100 g dw, respectively) while carbohydrates and ash content were 16.1 g/100 dw and 3.5 g/100 g dw. On the other hand, seed cakes contained a high amount ofprotein (58.6 g/100 g dw) and carbohydrates (28.4 g/1 00 g dw ). Ground seeds and seed cakes contained ali the four vitamin E isoforms (a-, p-, y- and S-tocopherols) with y-tocopherol being the most abundant isomer in both samples (6.59 mg/100 g dw and 1.07 mg/100 g dw, respectively). The main detected free sugar in ground seeds and seed cakes were sucrose, followed by trehalose, fructose and glucose, while seed cakes contained a higher amount of sucrose and total free sugars than ground seeds. Regarding the organic acids content, oxalic acid content was the only detected compound in seed cakes, whereas no organic acids were detected in ground seeds. The main detected fatty acids were linoleic acid (43.9% and 41.5% in ground seeds and seed cakes, respectively) and oleie acid (37.0% and 36.3% in ground seeds and seed cakes, respectively), followed by stearic acid (4.83% and 5.46% in ground seeds and seed cakes, respectively). Polyunsaturated and unsaturated fatty acids were the main fatty acids class and accounted for 81.9% and 79.0% oftotal fatty acids in ground seeds and seed cakes, respectively. Finally, both materiais showed no toxic effects against non-tumor PLP2 cell lines indicating that they are safe for human consumption. ln, conclusion, the presented results highlighted the nutritional value of the tested materiais which could be considered a rich source of protein. Moreover, the high content in polyunsaturated fatty acids and tocopherols could be further valorized for pharmaceutical and nutraceutical purposes and increase the added value of pumpkin crop.
- Chemical profile and bioactive properties of green- and red-colored Basil cultivars as affected by nitrogen fertilizationPublication . Cruz, Luís Royer Oliveira; Fernandes, Ângela; Gioia, Francesco di; Petropoulos, Spyridon Α.; Polyzos, Nikolaos; Dias, Maria Inês; Pinela, José; Ferreira, Isabel C.F.R.; Barros, LillianBasil ( Ocimum basilicum L.) is an aromatic herb of the Lamiaceae family which has a high commercial value for having multiple purposes such as medicinal, nutrition, ornamental, cosmetics, religious and insecticida! or insect repellent purposes. It is a species with high genetic variability and numerous cultivars that do not differ significantly in morphological terms but present differences from the chemical composition point of view. ln the present work, the chemical composition and bioactive properties of green and red-coloured cultivars were evaluated in relation to nitrogen fertilizer application rate. Three red-coloured (Dark Opal, Basilico Rosso and Red Basil) and one green-coloured landrace (Mitikas) of basil were grown under four nitrogen regimes, namely Control (no fertilizer added), 200 ppm, 400 ppm and 600 ppm of nitrogen (N). Fresh yield varied depending on N input following a quadratic function in all four genotypes, and green basil performed better compared to the red cultivars. A significant interaction of genotype x N input was recorded for most of the chemical parameters measured. Tocopherols contents of leaves were consistently higher in plants that received 200 ppm ofN and lower in those receiving 600 ppm ofN, especially in Dark Opal and Red Basil cultivars. Polyunsaturated fatty acids (PUF A) were the major category of fatty acids and Red basil had the lowest ratio of omega-6/omega 3 (0.29) and thus the best fatty acid profile. Polyphenols content was the highest in Red Basil and Dark Opal (25 mglg of extract on average) and the lowest in Mitikas and decreased with increasing N input. Similarly, antioxidant activity was the highest in Dark Opal and Red basil fertigated with 200 ppm ofN. ln conclusion, basil chemical and bioactive profile was significantly influenced by both genotype and N input. Red-coloured basil although less productive had the best chemical profile, and moderate leveis ofN input may provide the best compromise between yield, nutritional value and bioactivity for the species.
- Combinação de diferentes regimes de fertilização e irrigação para a produção de cardo dourado (Scolymus hispanicus L.) de alto valor nutricional e mineralPublication . Paschoalinotto, B.H.; Prieto Lage, Miguel A.; Polyzos, Nikolaos; Compocholi, Maria; Petropoulos, Spyridon Α.; Barros, Lillian; Dias, Maria InêsScolymus hispanicus L. (cardo dourado) é uma planta silvestre comestível que foi popularmente inserida no passado na Dieta Mediterrânica e que caiu em desuso em prol de outras espécies mais apreciadas pelo consumidor [1]. Considerando a atual preocupação por uma alimentação mais funcional e, consequentemente, mais saudável dos consumidores, a par da perda de biodiversidade pela colheita irracional de espécies silvestres de alto valor acrescentado, é de extrema importância desenvolver uma produção racional, padronizada e sustentável destas plantas com um perfil nutricional e mineral que se coadunem com as exigências dos consumidores. A otimização dos regimes de fertilização e o uso racional da água têm sido dos fatores mais estudados pela academia e implementados pelos agricultores para aumentar o rendimento das suas culturas [2,3]. O objetivo do presente estudo foi avaliar o efeito da fertilização com soluções nutritivas contendo diferentes proporções de azoto, fósforo e potássio (N:K:P) bem como o efeito do regime de irrigação no perfil nutricional e mineral das folhas de S. hispanicus. Os conteúdos de proteína bruta (Pr), gordura (G), cinzas (C) e fibras dietéticas (FD) totais foram avaliados através de métodos AOAC e hidratos de carbono (HC) por diferença. O conteúdo de minerais avaliado por feito por AAS. A energia foi calculada de acordo com a equação: 4 x (g Pr + g HC) + 2 x (g FD) + 9 x (g G). Os controlos usados foram produzidos sem fertilização (SHFC) e com irrigação feita com água da chuva (SHIC). Os regimes de irrigação tiveram um maior impacto positivo no conteúdo de Pr, C e FD totais quando do que os regimes de fertilização via solução nutritiva, revelando maiores teores desses macronutrientes funcionais e consequentemente, menores teores de HC. O conteúdo de G não foi afetado. A fertilização com 300:200:100 ppm (N:P:K) revelou o maior conteúdo energético bem como de HC. O perfil mineral obtido em todos os tratamentos aplicados foi bastante distinto, o que era expectável. Com a produção em hidroponia acoplada à irrigação foram obtidos maiores teores de ferro, cálcio e potássio; no entanto o controlo em hidroponia apresentou maiores teores de sódio. A maior concentração de manganês foi obtida nas amostras com irrigação de 100:100:100 ppm (N:P:K). Os impactos dos diferentes regimes de fertilização e irrigação na qualidade nutricional e conteúdo mineral são evidentes; sendo necessários para o desenvolvimento de sistemas agrícolas sustentáveis
- Combined effect of biostimulants and mineral fertilizers on crop performance and fruit quality of watermelon plantsPublication . Fernandes, Ângela; Polyzos, Nikolaos; Mandim, Filipa; Pereira, Carla; Petrović, Jovana; Soković, Marina; Petropoulos, Spyridon Α.The aim of the present study was to evaluate the possible effects of two different biostimulant formulations at different application regimes and combined or not with mineral fertilizers (e.g., W1–W8, including the control treatment (no formulations added)) on the yield parameters and fruit quality of watermelon plants. The highest yield was recorded for the W5 treatment due to the formation of more fruit. The highest content of fat, proteins and ash was recorded for treatment W1, whereas carbohydrates were the most abundant in the control treatment, resulting also in the highest energetic value. The main detected sugars in all the tested samples were sucrose and fructose, which were the highest for the W4 and W5 treatments (sucrose) and W4 treatment (fructose). Malic and citric acid were the most abundant compounds, especially in the W4 treatment. In terms of tocopherols, only -tocopherol was detected, with the highest amounts being recorded for the W4 treatment. Regarding bioactive properties, the lowest IC50 values for OxHLIA were recorded for the W2, W3 and W8 formulations. Moreover, all the extracts exhibited significant anti-inflammatory activity comparable to the positive control, while a variable efficacy of the tested extracts against the studied bacteria and fungi was recorded. In conclusion, our results indicate that simple agronomic practices such as biostimulant application may improve crop performance and improve the proximal composition and the overall quality of watermelon fruit within the context of sustainable crop production.
- Crop rotation and irrigation regime affects the nutritional and chemical profile of Cichorium spinosumPublication . Paschoalinotto, B.H.; Prieto Lage, Miguel A.; Compocholi, Maria; Polyzos, Nikolaos; Petropoulos, Spyridon Α.; Ferreira, Isabel C.F.R.; Dias, Maria Inês; Barros, LillianThe sustainable management of agricultural systems offers synergistic opportunities for the co-production of agricultural and natural capital outcomes.1 A properly sized agricultural system is essential for the sustainable and ecological maintenance of crop productivity. Irrigation management is an important adaptation strategy to improve crop resilience to global climate change while crop rotation brings benefits such as increased crop yields through high soil fertility and reduced fertilizer inputs.2 Cichorium spinosum L. (spiny chicory) is a wild edible plant that has received very recent attention as a potential alternative/complementary crop. It is a plant traditionally consumed in the so-called Mediterranean diet due to its high nutritional value and various beneficial health effects.3 The study aims to improve and integrate the cultivation of this species in farming systems of the Mediterranean region. Thus, a combination of full or deficit irrigation with or without crop rotation with maize was established in an attempt to establish the commercial cultivation of spiny chicory. Two control samples were cultivated: C0 (rain-feed with crop rotation with maize) and C00 (rain-feed without crop rotation). The nutritional profile was evaluated using AOAC methods. Energy was calculated according to the equation: energy (kcal per 100 g) = 4 x (g protein + g carbohydrate) + 2 x (g total dietary fiber) + 9 x (g fat). The profile of organic acids, minerals, fatty acids and sugars were performed using UFLC-PDA, atomic absorption spectrophotometry, GC-FID and HPLC-RI, respectively. Although the impacts that a sustainable farming system generates on the crop involved is a long-term assessment and after the system has been repeated for several growing periods, however some changes are already noticeable in the first growing period. In the nutritional profile, there were no differences between the six experimental treatments, with the exception of the total dietary fiber content which samples C0 (control) and CFIC (full irrigation with crop rotation with maize) showed the highest levels. The samples presented low values of total fat, being the sample C0 the one that presented the highest value (3.5 g/100g dry weight). Promising levels of crude protein were indicated by all samples, however once again the control sample had the highest content (C00). The CFIC and CFIN samples (full irrigation with and without crop rotation, respectively) showed the lowest values of carbohydrates. The sample CDIC (deficit irrigation with crop rotation with maize) showed the highest energy (276.3 kcal/100g dry weight) probably due to the low fiber content and consequently the high carbohydrate content. Five organic acids were identified in the spiny chicory samples, mostly quinic acid, except in the CFIN sample in which oxalic acid had the highest concentration. In terms of minerals, the samples with full irrigation showed higher concentrations of iron, manganese and copper and lower calcium, while the samples without crop rotation showed lower concentrations of potassium. The predominant fatty acids identified and quantified were linolenic, linoleic, and palmitic acids, the sum of which represented 82 to 86% in the studied samples, while the sample with deficit irrigation and without crop rotation (CDIN) presented the lowest percentage. Finally, the sugars identified in higher concentrations were sucrose, glucose, fructose, and trehalose, respectively, however, it is suggested that crop rotation with maize altered the profile of sugars by increasing their concentrations. Considering that these are preliminary results, it was possible to point out positive impacts of the tested agronomic practices on nutritional parameters of the species that could be commercially applied aiming to integrate wild edible species in sustainable and low inputs farming systems.
- Domestication of wild edible species: the response of Scolymus hispanicus plants to different fertigation regimesPublication . Paschoalinotto, B. H.; Polyzos, Nikolaos; Compocholi, Maria; Rouphael, Youssef; Alexopoulos, Alexios; Dias, Maria Inês; Barros, Lillian; Petropoulos, Spyridon Α.Scolymus hispanicus L. is a wild edible species with wide distribution in the Mediterranean area. Recent research has focused on the domestication of wild edible greens, which is essential for the preservation of agroecosystems and the increase in biodiversity, especially under the adversely changing climate conditions. In the present work, the aim was to evaluate the response of S. hispanicus plants to different fertilization regimes that varied in the amounts of nitrogen, phosphorus and potassium in regard to plant growth and chemical composition of leaves. For this purpose, plants were grown in pots within an unheated greenhouse. Seven experimental treatments were used, including six fertigation regimes (SH1-SH6) and the control treatment (SHC), where no fertilizers were added. Fresh yield was beneficially affected by the treatments that included a high content of P and K (e.g., SH3 and SH5), while lesser amounts of these macronutrients (e.g., SH1 and SH4) resulted in higher chlorophyll content (SPAD index) and leaf area. In terms of mineral profile, high amounts of P and K improved dietary fiber and carbohydrates content, whereas the untreated plants had the highest content of ash, fat and crude protein. Oxalic and quinic acid were the major organic acids detected, with fertigation regimes significantly reducing their content compared to the control treatment. α-tocopherol was the only isoform of vitamin E detected in all the samples, while glucose and fructose were the most abundant sugars, with their highest content detected in control and SH4 treatments, respectively. Scolymus hispanicus leaves were rich in macro and micro minerals, while their contents varied depending on the fertigation regime. Finally, α-linolenic, palmitic, and linoleic acid were the major fatty acids detected, while their contents were beneficially affected by low nutrient inputs (e.g., untreated plants and SH1 and SH2 treatments). In conclusion, the regulation of nutrient solution seems to be an effective practice to increase fresh yield in S. hispanicus without compromising the nutritional profile of the edible product, while low inputs of macronutrients such as P and K may improve the chemical composition of the species, especially in terms of n-fatty acids.
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