Not Available

Funder

Organizational Unit

Publications

Biofortification of Swiss chard micro- and baby greens with selenium and iodine

Publication . Pereira, Alexis; Dias, Maria Inês; Pinela, José

Agrifood systems are currently facing security due to their capacity to address the challenges posed by population growth, climate change, and depletion of natural resources.

2023Conference poster

Open access

Chemical and bioactive features of amaranthus caudatus l. flowers and optimized ultrasound-assisted extraction of betalains

Publication . Roriz, Custódio Lobo; Xavier, Virginie; Heleno, Sandrina A.; Pinela, José; Dias, Maria Inês; Calhelha, Ricardo C.; Morales, Patricia; Ferreira, Isabel C.F.R.; Barros, Lillian

The vibrant colours of many plants are due to secondary metabolites, such as nitrogen-containing compounds, where betacyanins are included. These compounds can be found in plants such as Amaranthus caudatus L. that, due to their high nutritional benefits, have been overproduced, which leads to the accumulation of large amounts of bio-residues. Among these bio-residues, the flowers which have a very intense pink colour and present no economic value or subsequent destination can be exploited as sources of natural colouring agents (betacyanins). This work aimed at characterising the flower’s extract in terms of bioactive molecules such as tocopherols, organic acids, but essentially in terms of betacyanins, in order to obtain a natural colouring agent. For the extraction, ultrasound-assisted extraction (UAE) ideal conditions were obtained using the Response Surface Methodology (RSM), allowing the attainment of an enriched extract of betacyanins in high yields and purity. The obtained extracts were analysed for their bioactive potential, namely antioxidant, antimicrobial and cytotoxic properties. From the obtained results, three isoforms of tocopherols were detected, β-tocopherol (0.884 ± 0.003 mg/100 g dry weight (dw)) being the most abundant one. Regarding the organic acids, oxalic (2.48 ± 0.05 mg/100 g dw), shikimic (0.170 ± 0.003 mg/100 g dw) and traces of fumaric acid were found. Four betacyanins were identified and quantified, namely: amaranthine (171 ± 1 mg/g extract), isoamaranthine (38 ± 1 mg/g extract), betanin (1.6 ± 0.1 mg/g), and isobetanin (1.3 ± 0.1 mg/g extract). The obtained extract also presented antioxidant activity with inhibition concentration (IC50 values) of 29.0 ± 0.4 µg/mL and 114 ± 4 µg/mL for âˆ†t of 60 min and 120 min, respectively in the oxidative haemolysis inhibition assay (OxHLIA) assay. The obtained extract also presented an interesting antibacterial activity with minimum inhibitory concentrations ranging from 5 to 20 mg/mL against pathogenic bacteria and revealed no toxicity for normal cells.

2021Journal article

Open access

Melhoria do valor nutricional de microvegetais de acelga através de biofortificação com selénio em agricultura vertical

Publication . Pereira, Alexis; Dias, Maria Inês; Oliveira, Beatriz; Pinela, José

Os sistemas agroalimentares atuais enfrentam grandes desafios associados ao crescimento populacional, às alterações climáticas e ao esgotamento de recursos naturais. Além disso, a deficiência de micronutrientes essenciais, como o selénio, afeta milhões de pessoas em todo o mundo e está associada a sérios problemas de saúde. As alterações climáticas podem agravar esta carência ao reduzir os níveis de selénio nos solos agrícolas e, consequentemente, nos alimentos. Portanto, combater a insegurança alimentar e a malnutrição é uma prioridade na Agenda 2030 da ONU para o Desenvolvimento Sustentável. Objetivos: Este estudo teve como objetivo produzir e biofortificar microvegetais de acelga com selénio em ambiente controlado e avaliar a sua qualidade nutricional. Metodologia: Os microvegetais de acelga foram cultivados sob condições controladas de temperatura, humidade e fotoperíodo. O selénio foi suplementado através da solução nutritiva como selenito e selenato de sódio em concentrações de 10 a 40 µM. A colheita foi realizada 14 dias após a germinação. Os microvegetais foram analisados quanto à sua composição em elementos minerais (incluindo selénio), ácidos orgânicos, açúcares livres, compostos fenólicos e betalaínas, usando técnicas espectroscópicas e cromatográficas. Resultados: As análises em curso permitirão avaliar o perfil de nutrientes (minerais, ácido ascórbico e açúcares) e constituintes bioativos (compostos fenólicos e betalaínas) nos microvegetais de acelga. Além disso, permitirão identificar a forma inorgânica e a concentração de selénio mais adequadas para a biofortificação dos microvegetais. Discussão: Espera-se que este estudo contribua para o desenvolvimento de métodos de produção alimentar sustentáveis e inteligentes em termos climáticos, capazes de melhorar a qualidade nutricional dos microvegetais de acelga, através do aumento dos teores de selénio e possivelmente de outros micronutrientes. Estes alimentos poderão ajudar a mitigar a deficiência de selénio, particularmente em populações vulneráveis.

2024Conference poster

Open access

Nutritional and bioactive traits of Kweli® red raspberry cultivated in Portugal

Publication . Rodrigues, Matilde; Vara, Ana Luísa; Petrović, Jovana; Dias, Maria Inês; Nogueira, António José M.; Soković, Marina; Ferreira, Isabel C.F.R.; Pinela, José; Barros, Lillian

Red raspberry (Rubus idaeus L.) is an increasingly popular food in contemporary diets due to its freshness, organoleptic features, nutritional value, and health claims. From the nutritional point of view, red raspberry has been described as containing vitamins, minerals, soluble fiber, reducing sugars, citric acid, and phenolic compounds.1 Anthocyanins are of particular interest in this fruit, since these pigments provide the characteristic red-purple color, as well as bioactive properties.1,2 The demand for raspberries has risen sharply in Europe and North America and, among the existing cultivars, Kweli® is one of the most productive and suitable for growing in moderate and Mediterranean climates. High levels of ellagitannins, anthocyanins, and vitamin C have been described in this cultivar and its phytochemical content has been correlated with antioxidant properties.1,2 Still, little else is known about the nutritional composition of Kweli®. Therefore, this work was performed to characterize the nutritional and chemical composition of this red raspberry cultivar gown in northern Portugal and assess its in vitro antioxidant and antimicrobial activities. Fresh fruits at commercial maturity were harvested and immediately lyophilized. Its proximate composition was determined by official method of food analysis and the concentrations of free sugars, organic acids, tocopherols, and fatty acids were evaluated by different chromatographic techniques.3 Anthocyanins were identified in an hydroethanolic extract prepared by solid-liquid extraction, which was also used to evaluate bioactive properties.3 The antioxidant activity was evaluated via inhibition of β-carotene bleaching, formation of thiobarbituric acid reactive substances (TBARS), and oxidative hemolysis.3 The antimicrobial activity was tested against foodborne bacterial and fungal strains by microdilution methods.3 Moisture (approximately 83%) and carbohydrates (16.12%), of which fructose (2.42%) and glucose (2.13%), were major constituents of Kweli® red raspberry, followed by ash (0.66%) and protein (0.18%). The fat content was quite low and consisted mainly by unsaturated fatty acids (58%), with a prevalence of oleic acid. High levels of citric (2.7%) and ascorbic (17 mg/100 g) acids and tocopherols (1.92 mg/100 g) were also detected. The anthocyanins (4.51 mg/g extract) cyanidin-O-hexoside and mostly cyanidin-O-sophoroside were identified in the hydroethanolic extract, which was able to inhibit in some extent the formation of TBARS, oxidative hemolysis, and β-carotene bleaching. In turn, the extract was more effective than the food additive E224 against Bacillus cereus. Overall, these results highlighted the nutritional quality of Kweli® red raspberry and may be useful to complete food composition databases. Therefore, the inclusion of this berry in a daily diet can be helpful to obtain nutrients and antioxidants and bring health benefits.

2022Conference object

Open access

Natural food ingredients from quince peel: towards a "zero-waste" production system

Publication . Pereira, Alexis; Añibarro-Ortega, Mikel; Rodrigues, Matilde; Nogueira, António José M.; Pinela, José; Barros, Lillian

Quince is the yellow fruit of the deciduous tree Cydonia oblonga Mill. Its taste is sour and astringent when eaten raw, so it is usually processed into marmalade and many other food products, mostly sweets, through processes that discard the peel as a by-product. Therefore, this work was carried out to promote the upcycling of quince peel into valuable food ingredients following a "zero waste" approach. A response surface methodology (RSM)-coupled experimental design with 20 runs, combining five levels of time (1–120 min), temperature (25–95 °C) and ethanol concentration (0–100%), was implemented for maximizing the extraction of soluble solids and malic acid while simultaneously obtaining fiber concentrate extracts. The yields of soluble solids and fiber concentrate extracts were determined gravimetrically. Malic acid, which has been used as a food preservative, was analyzed by ultra-fast liquid chromatography with photodiode array detection.1 The dietary fiber content of the fiber concentrate extracts was determined by an enzymatic-gravimetric method (AOAC Official Method 985.29) and their color was measured with a portable colorimeter.2,3 The three independent variables affected significantly the extraction process and the predictive model equations were validated based on different statistical criteria, which allowed to determine the optimal extraction conditions. In general, the soluble solids yield was promoted by lower temperatures and ethanol concentrations, while malic acid was better extracted at higher temperatures for longer processing times. In turn, the fiber concentrate extracts remaining after extraction had opposite yields to the soluble solids. However, the highest yields of these fiber concentrates were not in agreement with their dietary fiber contents. The highest fiber values were recorded in the concentrate extracts obtained at high temperatures and medium-low ethanol concentrations. In fact, only these two independent variables significantly impacted its extraction, through linear, quadratic, and also interactive effects. Furthermore, the lighter fiber concentrate extracts were those with the highest yields. Overall, quince peel can be totally upcycled into natural food ingredients rich in malic acid and dietary fiber.

2022Conference object

Open access