Laboratory of Separation and Reaction Engineering - Laboratory of Catalysis and Materials

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Edible flowers of Helichrysum italicum: Composition, nutritive value, and bioactivities

Publication . Primitivo, Maria João; Neves, Marta; Pires, Cristiana L.; Cruz, Pedro F.; Brito, Catarina; Rodrigues, Ana C.; Carvalho, Carla C. C. R. de; Mortimer, Megan M.; Moreno, Maria João; Brito, Rui M. M.; Taylor, Edward J.; Millson, Stefan H.; Reboredo, Fernando; Campos, Maria; Vaz, Daniela C.; Ribeiro, Vânia

Helichrysum italicum (H. italicum) is a halophyte shrub with bright yellow flowers with a strong curry-like aroma. The essential oils of H. italicum have been used in the production of cosmetics and pharmaceuticals, due to their antiallergic and anti-inflammatory properties. In the agri-food sector, H. italicum flowers can be used for seasoning and flavoring food, and as natural food preservatives. Here, we report on the composition, bioactive compounds, and nutritive value of H. italicum flowers. Flowers were mainly composed of carbohydrates (>80 % dry weight), followed by minerals (6.31 ± 0.95 % dw), protein (5.44 ± 0.35 % dw), and lipids (3.59 % ± 0.53 % dw). High percentages of Fe, Zn, Ca, and K were found in the flower material, along with a high content in antioxidants, polyphenols, and carotenoids, as corroborated by the nuclear magnetic resonance (NMR) data. Flowers were mainly composed of saturated fatty acids (SFAs) (54.50 ± 0.95 % of total FA), followed by polyunsaturated fatty acids (PUFAs) (37.73 ± 1.25 % of total FA) and monounsaturated fatty acids (MUFAs) (7.77 ± 0.34 %), as detected by gas chromatography mass spectrometry (GC–MS). The omega-6 PUFA linoleic acid (22.55 ± 0.76 % of total FA) was the most abundant fatty acid found. Flower extracts showed antimicrobial activity against Saccharomyces cerevisiae and Komagataella phaffii, as well as against Gram-negative (Klebsiella pneumoniae) and Gram-positive (Staphylococcus aureus) bacteria. H. italicum flower material was nontoxic to human intestinal Caco-2 model cells at concentrations up to 1.0 % w/v.

2022Journal article

Restricted access

Wastewater as a nutrient source for hydroponic production of lettuce: Summer and winter growth

Publication . Santos, Ounísia; Vaz, Daniela; Sebastião, Fernando; Sousa, Helena; Vieira, Judite

Solutions combining soilless cropping systems with wastewater reuse can offer benefits in the agriculture sector, reducing pressure on water resources, promoting sustainable production, and reclaiming wastewater. However, assessing the sanitary risks associated with wastewater reuse is of utmost importance. This study aimed to investigate the hydroponic growth of lettuce (Lactuca sativa var. crispa L.) in wastewater from an urban treatment plant with different levels of treatment and evaluate potential sanitary risks. Crop growth took place in a greenhouse, during summer and winter periods, using wastewater after primary (PTW) or secondary (STW) treatment, and a nutrient solution (NS), as control. Physical and chemical water quality parameters, morphological crop growth parameters, and environmental conditions inside the greenhouse were monitored. Toxicity analyses were carried out through cell viability assays with the Caco-2 cell line and total coliforms and Escherichia coli (E. coli) were determined. Wastewater-grown plants achieved acceptable growth, even though presenting lower fresh weight than NS-plants. STW-plants’ growth was limited essentially by nutrient deficiency, and PTW-plants were affected by nutrient deficiency, pH values, solid load, and N-NO2 concentration. Higher temperatures in summer led to faster crop growth, and lower temperatures in winter allowed better nutrient uptake by the crop. Wastewater-grown plants did not evidence toxicity in leaf extracts up to 1 % w/v. Coliform enumeration data indicated an accumulation in plant roots, with high removal from the wastewater. E. coli was not detected on plants’ leaves and total coliforms were within acceptable limits. Furthermore, the results point to an improvement in the wastewater quality, with minimum removal values of 75.2 % BOD5, 83.1 % COD, 43.4 % P, 44.9 % N, and 90.4 % K. The results demonstrated the viability of wastewater reuse for hydroponic production allowing a better understanding of its processes and contributing to mitigating water scarcity for food production, and the impacts of treated wastewater discharge in freshwater courses, particularly those associated with nutrient delivery to aquatic systems.

2024-08Journal article

Open access

Development and characterization of films for food application incorporating porphyran extracted from Porphyra dioica

Publication . Teles, Marco; Adão, Pedro; Afonso, Clélia; Bernardino, Raul; Guedes, Mafalda; Baptista, Ricardo; Bernardino, Susana

Non-biodegradable plastic is one of the biggest environmental problems of our lifetime and, considering the present societal needs, it will get worse. Consequently, there is an urgent need to develop sustainable and renewable alternatives to plastic, such as plastic-like materials obtained from biodegradable polymers, namely sulfated polysaccharides, considered one of the most viable alternatives. There is also a need to obtain these materials in an environmentally and economically sustainable way. The hereby developed process of obtaining film-forming solutions from semi-refined porphyran (PorphSR) uses a green solvent (hot water) with a high extraction yield of semi-refined porphyran (26.66 +- 0.27%) in a reproducible way and with low levels of contaminants. The obtained semi-refined porphyran showed good antioxidant potential in all tests performed: HPSA (D0.066 +- 0.002), DPPH (2.23 +- 0.78%), FRAP (0.420 +- 0.014 eq. ascorbic acid ug mg-1 of extract) and ABTS (20.46 0.90%). After being cast into films, the most notable antioxidant properties were those of the semi-refined porphyran in the DPPH, FRAP and ABTS assays and of the pectin, (PorphSR_PcT and PorphSR_PcT_Gly) in the HPSA assay. Morphologically, the films showed relatively homogeneous and low roughness surfaces. It is concluded that the described method to obtain semi-refined porphyran is feasible and reproducible, and that the developed films, mainly PorfP2_PcT_Gly, proved to be a potential candidate for non-biodegradable plastic substitutes.

2022Journal article

Open access

Development and characterization of flms for food application incorporating Porphyran extracted from Porphyra dioica

Publication . Teles, Marco; Adão, Pedro; Afonso, Clélia; Bernardino, Raul; Guedes, Mafalda; Baptista, Ricardo; Bernardino, Susana

Non-biodegradable plastic is one of the biggest environmental problems of our lifetime and, considering the present societal needs, it will get worse. Consequently, there is an urgent need to develop sustainable and renewable alternatives to plastic, such as plastic-like materials obtained from biodegradable polymers, namely sulfated polysaccharides, considered one of the most viable alternatives. There is also a need to obtain these materials in an environmentally and economically sustainable way. The hereby developed process of obtaining film-forming solutions from semi-refined porphyran (PorphSR) uses a green solvent (hot water) with a high extraction yield of semi-refined porphyran (26.66 +- 0.27%) in a reproducible way and with low levels of contaminants. The obtained semi-refined porphyran showed good antioxidant potential in all tests performed: HPSA (D0.066 +- 0.002), DPPH (2.23 +- 0.78%), FRAP (0.420 +- 0.014 eq. ascorbic acid ug mg-1 of extract) and ABTS (20.46 +- 0.90%). After being cast into films, the most notable antioxidant properties were those of the semi-refined porphyran in the DPPH, FRAP and ABTS assays and of the pectin, (PorphSR_PcT and PorphSR_PcT_Gly) in the HPSA assay. Morphologically, the films showed relatively homogeneous and low roughness surfaces. It is concluded that the described method to obtain semi-refined porphyran is feasible and reproducible, and that the developed films, mainly PorfP2_PcT_Gly, proved to be a potential candidate for non-biodegradable plastic substitutes.

2021Journal article

Open access

Nutritive Value and Bioactivities of a Halophyte Edible Plant: Crithmum maritimum L. (Sea Fennel)

Publication . Correia, Iris; Antunes, Madalena; Tecelão, Carla; Neves, Marta; Pires, Cristiana L.; Cruz, Pedro F.; Peralta, Claúdia C.; Pereira, Cidália D.; Reboredo, Fernando; Moreno, Maria João; Brito, Rui M. M.; Ribeiro, Vânia S.; Vaz, Daniela C.; Campos, Maria; Rodrigues, Maria Jorge

Crithmum maritimum L. (sea fennel), an edible xerophyte of coastal habitats, is considered an emerging cash crop for biosaline agriculture due to its salt-tolerance ability and potential applications in the agri-food sector. Here, the nutritional value and bioactive properties of sea fennel are described. Sea fennel leaves, flowers, and schizocarps are composed of carbohydrates (>65%) followed by ash, proteins, and lipids. Sea fennel’s salty, succulent leaves are a source of omega-6 and omega-3 polyunsaturated fatty acids, especially linoleic acid. Extracts obtained from flowers and fruits/schizocarps are rich in antioxidants and polyphenols and show antimicrobial activity against Staphylococcus aureus, Staphylococcus epidermis, Candida albicans, and Candida parapsilosis. Plant material is particularly rich in sodium (Na) but also in other nutritionally relevant minerals, such as calcium (Ca), chlorine (Cl), potassium (K), phosphorus (P), and sulfur (S), beyond presenting a potential prebiotic effect on Lactobacillus bulgaricus and being nontoxic to human intestinal epithelial Caco-2 model cells, up to 1.0% (w/v). Hence, the rational use of sea fennel can bring nutrients, aroma, and flavor to culinary dishes while balancing microbiomes and contributing to expanding the shelf life of food products.

2024Journal article

Open access