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Research Project
Linking Landscape, Environment, Agriculture and Food
Funder
Authors
Publications
Enrichment of Sunflower Oil with Ultrasound-Assisted Extracted Bioactive Compounds from Crithmum maritimum L.
Publication . Sousa, Gabriela; Alves, Mariana I.; Neves, Marta; Tecelão, Carla; Ferreira-Dias, Suzana
Crithmum maritimum L., or sea fennel, is an edible halophyte plant, rich in phenolic compounds
with antioxidant and antimicrobial activities, that naturally grows in Mediterranean coasts.
This study aims to incorporate bioactive compounds extracted from lyophilized Crithmum maritimum
to sunflower oil assisted by ultrasounds (UAE), to improve its biological value and oxidative stability.
UAE conditions were optimized as a function of time (5–20 min) and lyophilized plant concentration
(5–20% m/v). The experiments were dictated by a central composite rotatable matrix. Oxidation
products were not influenced by UAE conditions. Acidity, chlorophyll, and carotenoid contents were
affected by both factors, while total phenols, flavonoids, and antioxidant activity (FRAP method)
only increased with plant concentration. Response surfaces were fitted to these experimental results.
Flavonoids were highly related with oil antioxidant activity. No sensory defects were detected in
supplemented oil (12.5% m/v plant/5 min UAE). The oxidative stability of this oil was evaluated
at 60 C/12 days. Chlorophylls, phenols, radical scavenging (DPPH), and antioxidant activities
decreased over time but were always higher than the values in non-supplemented oil (8.6 and 7-fold
with FRAP and DPPH, respectively). C. maritimum presented high amounts of bioactive compounds
with antioxidant activity, adequate for sunflower oil supplementation by UAE
Impact of grass pea sweet miso incorporation in vegan emulsions: rheological, nutritional and bioactive properties
Publication . Simões, Sara; Sanchez, Cecilio Carrera; Santos, Albano Joel; Figueira, Diogo; Prista, Catarina; Raymundo, Anabela
Grass pea (Lathyrus sativus L.) is a pulse with historical importance in Portugal, but that
was forgotten over time. Previous to this work, an innovative miso was developed to increase
grass pea usage and consumption, using fermentation as a tool to extol this ingredient. Our work’s
goal was to develop a new vegan emulsion with added value, using grass pea sweet miso as a
clean-label ingredient, aligned with the most recent consumer trends. For this, a multidisciplinary
approach with microbiological, rheological and chemical methods was followed. Grass pea sweet
miso characterization revealed a promising ingredient in comparison with soybean miso, namely for
its low fat and sodium chloride content and higher content in antioxidant potential. Furthermore,
in vitro antimicrobial activity assays showed potential as a preservation supporting agent. After
grass pea sweet miso characterization, five formulations with 5–15% (w/w) of miso were tested, with
a vegan emulsion similar to mayonnaise as standard. The most promising formulation, 7.5% (w/w)
miso, presented adequate rheological properties, texture profile and fairly good stability, presenting
a unimodal droplet size distribution and stable backscattering profile. The addition of 0.1% (w/w)
psyllium husk, a fiber with great water-intake capacity, solved the undesirable release of exudate from
the emulsion, as observed on the backscattering results. Furthermore, the final product presented a
significantly higher content of phenolic compounds and antioxidant activity in comparison with the
standard vegan emulsion.
Methicillin resistance of food-borne biofilm-forming staphylococci
Publication . Salamandane, Acácio; Correia, Jussara; Muetanene, Belo Afonso; Santos, Madalena dos; Malfeito-Ferreira, Manuel; Brito, Luisa
The aim of this study was to evaluate the biofilm-forming ability and the resistance of
planktonic cells and biofilm to methicillin (MIC and MBC, and log CFU/cm2 reduction, respectively).
Thirty-four isolates were used, including coagulase-positive Staphylococcus (CPS) and coagulasenegative
Staphylococcus (CNS), recovered from ready-to-eat (RTE) foods. Biofilm-forming ability was
based on enumeration of viable cells from biofilms formed on three types of surfaces, namely stainless
steel, polystyrene, and glass. Thirteen of the thirty-four isolates (38.2%) were methicillin-resistant
(MIC higher than 4 g/mL). Staphylococcus aureus (CPS) and Staphylococcus saprophyticus (CNS)
were the species that showed the highest percentage of resistance (50% and 71.4%, respectively).
Staphylococcus warneri was the only species susceptible to methicillin. In 20 of the 34 isolates, the
MBC value was twice the MIC value. The CPS (S. aureus) and the CNS (the other species) were
not significantly different (p > 0.05) on biofilm-forming ability on the three surfaces used. However,
when comparing the averages obtained for the biofilm-forming ability of the isolates, the
values obtained (log CFU/cm2) in polystyrene were significantly higher (p < 0.05) than those obtained
with the isolates on stainless steel. On the other hand, data from biofilm-forming ability of
the isolates on glass and stainless steel are positively and significantly correlated with each other
(r = 0.54; p = 0.02). It was not possible to determine the concentration of methicillin that promotes
biofilm removal since log reductions were less than 3 log CFU/cm2. The results of this study indicate
that foodborne CPS and CNS can form biofilms on different types of material. As these biofilms
are resistant to high concentrations of methicillin, their occurrence in food environments and their
spread to medical settings can result in staphylococcal food poisoning or, in the worst-case scenario,
septicemia, respectively. Good hygiene and good manufacturing practices (GHP and GMP) are
therefore mandatory to prevent contamination with Staphylococcus spp.
Halotolerant endophytes promote grapevine regrowth after salt-induced defoliation
Publication . Navarro-Torre, Salvadora; Ferrario, Sara; Caperta, Ana D.; Victorino, Gonçalo; Bailly, Marion; Sousa, Vicelina; Viegas, Wanda; Nogales, Amaia
Salinity is an important problem for agriculture in the Mediterranean area, and thus, it is essential to
develop mitigation strategies to reduce its impact. The main objective of this study was to test the
effectiveness of halotolerant plant growth-promoting bacteria (H-PGPB) in improving grapevine
salt stress tolerance. Grapevines grafted onto a salt-sensitive rootstock were inoculated with a
consortium of H-PGPB. The substrate of half of the plants of each treatment was salinized up to
2 dS m−1
. Plants grew for six days under these conditions, and afterward, NaCl was removed to
assess plant recovery through growth, physiology, and canopy temperature measurements.
Inoculation with H-PGPB had a positive effect on plant physiology, but after salt treatment,
grapevines stopped their photosynthetic metabolism, leading to severe defoliation. Remarkably,
after salt stress removal, inoculated plants re-sprouted faster, demonstrating that H-PGPB
inoculation could be a good practice to increase vineyard resilience to salt stress
3D printed gluten-free cereal snack with incorporation of Spirulina (Arthrospira platensis) and/or Chlorella vulgaris
Publication . Letras, P.; Oliveira, S.; Varela, J.; Nunes, M.C.; Raymundo, Anabela
3D food printing is a recent technology promising to break cultural barriers by introducing new food sources such
as microalgae, through innovative food shapes and textures, in a resource-scarce world whose sustainability is at
stake because of the current intensive production of meat and agriculture products. The present work intends to
create an innovative gluten-free cereal snack nutritionally improved by the incorporation of Chlorella vulgaris and
Arthrospira platensis (“Spirulina”) biomass using 3D printing technology. Doughs without (control) or with
microalgal biomass with different incorporation percentages (from 5 to 30 %) were tested and those showing the
most adequate rheology (low viscoelastic moduli and apparent viscosity) and texture (low firmness, adhesiveness
and high cohesiveness) properties for a correct printing process were selected and baked (control and 5 %
microalgae incorporation). Nutritional characterization of the control and 5 % snacks was performed, in terms of
total protein and lipid contents, ash, humidity, water activity, energy, and carbohydrates, as well as total phenolics,
pigments and antioxidant activity. Physical traits of snacks, including their colour and size, were also
analysed. Control snacks presented a lighter and yellow colour compared to snacks containing Chlorella and
Spirulina, which had higher green chromaticity (Control: a* - 0.953, b* 21.3; Chlorella 5 %: a* - 2.20, b* 11.8;
Spirulina 5 %: a* -1.05, b* 3.55). Nutritional characterization revealed that snacks containing Chlorella and
Spirulina had both higher protein and essential minerals content. Overall, 5 % Spirulina snacks presented the
best nutritional and sensory performance, with higher antioxidant activity, mineral and protein contents. These
Spirulina-snacks deserved a positive sensory appreciation from consumers
Organizational Units
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Contributors
Funders
Funding agency
Fundação para a Ciência e a Tecnologia
Funding programme
6817 - DCRRNI ID
Funding Award Number
UIDB/04129/2020