Diana Santos

Ms. Diana Santos

Linking Landscape, Environment, Agriculture and Food (LEAF), Instituto Superior de Agronomia (ISA), Universidade de Lisboa, Lisbon, Portugal
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Research Focus & Metrics

Academic Career Length

13Years (2014-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 January 2019
Verified
Book Chapter
Closed access
DSDiana Santos
Diana Santos
JSJorge Manuel Alexandre Saraiva
Jorge Manuel Alexandre Saraiva
AVAntónio A. Vicente
António A. Vicente
MMMargarida Moldão-Martins
Margarida Moldão-Martins

1 June 2021 in Foods
Verified
Journal Article
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Sofia C. LourençoSofia C. Lourenço
Sofia C. Lourenço
Débora CamposDébora Campos
Débora Campos
Ricardo Gómez GarcíaRicardo Gómez García
Ricardo Gómez García
Manuela PintadoManuela Pintado
Manuela Pintado
MOMaria Conceição Monteiro André Oliveira
Maria Conceição Monteiro André Oliveira
Vitor D. AlvesVitor D. Alves
Vitor D. Alves
Pineapple peel still contains an important amount of phenolic compounds and vitamins with valuable antioxidant activity. In this way, the aim of this study was the recovery of the bioactive compounds from pineapple peel using environmentally friendly and low-cost techniques, envisaging their application in food products. From the solid-liquid extraction conditions tested, the one delivering an extract with higher total phenolic content and antioxidant capacity was a single extraction step with a solvent-pineapple peel ratio of 1:1 (w/w) for 25 min at ambient temperature, using ethanol-water (80–20%) as a solvent. The resulting extract revealed a total phenolic content value of 11.10 ± 0.01 mg gallic acid equivalent (GAE)/g dry extract, antioxidant activity of 91.79 ± 1.98 µmol Trolox/g dry extract by the DPPH method, and 174.50 ± 9.98 µmol Trolox/g dry extract by the FRAP method. The antioxidant rich extract was subjected to stabilization by the spray drying process at 150 °C of inlet air temperature using maltodextrin (5% w/w) as an encapsulating agent. The results showed that the antioxidant capacity of the encapsulated compounds was maintained after encapsulation. The loaded microparticles obtained, which consist of a bioactive powder, present a great potential to be incorporated in food products or to produce bioactive packaging systems.

27 May 2021 in Molecules
Verified
Journal Article
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DSDiana Santos
Diana Santos
CMCátia Falcão Martins
Cátia Falcão Martins
RARenata Amaral
Renata Amaral
LBLuisa Brito
Luisa Brito
JSJorge Manuel Alexandre Saraiva
Jorge Manuel Alexandre Saraiva
MMMargarida Moldão-Martins
Margarida Moldão-Martins
Pineapple is consumed on a large scale around the world due to its appreciated sensorial characteristics. The industry of minimally processed pineapple produces enormous quantities of by-products (30–50%) which are generally undervalued. The end-of-life of pineapple by-products (PBP) can be replaced by reuse and renewal flows in an integrated process to promote economic growth by reducing consumption of natural resources and diminishing food waste. In our study, pineapple shell (PS) and pineapple core (PC), vacuum-packed separately, were subjected to moderate hydrostatic pressure (225 MPa, 8.5 min) (MHP) as abiotic stress to increase bromelain activity and antioxidant capacity. Pressurized and raw PBP were lyophilized to produce a stable powder. The dehydrated samples were characterized by the following methodologies: chemical and physical characterization, total phenolic compounds (TPC), antioxidant capacity, bromelain activity, microbiology, and mycotoxins. Results demonstrated that PBP are naturally rich in carbohydrates (66–88%), insoluble (16–28%) and soluble (2–4%) fiber, and minerals (4–5%). MHP was demonstrated to be beneficial in improving TPC (2–4%), antioxidant activity (2–6%), and bromelain activity (6–32%) without affecting the nutritional value. Furthermore, microbial and mycotoxical analysis demonstrated that powdered PC is a safe by-product. PS application is possible but requires previous decontamination to reduce the microbiological load.

3 October 2019 in Applied Sciences
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Journal Article
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DSDiana Santos
Diana Santos
MCMaria Joana Neiva Correia
Maria Joana Neiva Correia
MMMaria Mateus
Maria Mateus
JSJorge Manuel Alexandre Saraiva
Jorge Manuel Alexandre Saraiva
AVAntónio Vicente
António Vicente
MMMargarida Moldão-Martins
Margarida Moldão-Martins
Fourier transform infrared (FT-IR) spectroscopy is a physicochemical technique based on the vibrations of a molecule energized by infrared radiation at a specific wavelength range. Abiotic stresses can induce the production of secondary metabolites, increasing bioactivity. The objectives of the study were to evaluate the impact of heat treatments on the bioactivity of pineapple by-products, and whether FT-IR analysis allows understanding of the changes imparted by abiotic stress. The by-products were treated at 30, 40, and 50 °C for 15 min, followed by storage at 5 ± 1 °C for 8 and 24 h. Lyophilized samples were characterized for total phenolic content and antioxidant capacity and analyzed by FT-IR. Thermal treatments at 50 °C reduced the content of phenolic compounds (21–24%) and antioxidant capacity (20–55%). Longer storage time (24 h) was advantageous for the shell samples, although this effect was not demonstrated for the core samples. The principal components analysis (PCA) model developed with the spectra of the pineapple shell samples showed that the samples were grouped according to their total phenolic compounds content. These results allow the conclusion to be drawn that FT-IR spectroscopy is a promising alternative to the conventional chemical analytical methodologies for phenolic and antioxidant contents if there are significant differences among samples.

13 July 2022 in Bioengineering
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Journal Article
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LCLuiz Carlos Correa-Filho
Luiz Carlos Correa-Filho
DSDiana Santos
Diana Santos
LBLuisa Brito
Luisa Brito
MMMargarida Moldão-Martins
Margarida Moldão-Martins
Vitor D. AlvesVitor D. Alves
Vitor D. Alves
Tomato pomace is rich in carotenoids (mainly lycopene), which are related to important bioactive properties. In general, carotenoids are known to react easily under environmental conditions, which may create a barrier in producing stable functional components for food. This work intended to evaluate the storage stability and in vitro release of lycopene from encapsulated tomato pomace extract, and its bioaccessibility when encapsulates were incorporated in yogurt. Microencapsulation assays were carried out with tomato pomace extract as the core material and arabic gum or inulin (10 and 20 wt%) as wall materials by spray drying (160 and 200 °C). The storage stability results indicate that lycopene degradation was highly influenced by the presence of oxygen and light, even when encapsulated. In vitro release studies revealed that 63% of encapsulated lycopene was released from the arabic gum particles in simulated gastric fluid, whereas for the inulin particles, the release was only around 13%. The feed composition with 20% inulin showed the best protective ability and the one that enabled releasing the bioactives preferentially in the intestine. The bioaccessibility of the microencapsulated lycopene added to yogurt increased during simulated gastrointestinal digestion as compared to the microencapsulated lycopene alone. We anticipate a high potential for the inulin microparticles containing lycopene to be used in functional food formulations.

26 February 2015 in Food Science & Nutrition
Verified
Journal Article
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SMSilvia Moreira
Silvia Moreira
Pedro A. R. FernandesPedro A. R. Fernandes
Pedro A. R. Fernandes
RDRicardo Valente Duarte
Ricardo Valente Duarte
DSDiana Santos
Diana Santos
Liliana FidalgoLiliana Fidalgo
Liliana Fidalgo
JSJorge Manuel Alexandre Saraiva
Jorge Manuel Alexandre Saraiva
Hyperbaric storage (HS), storage under pressure at 25°C and 30°C, of a ready‐to‐eat (RTE) soup was studied and compared with refrigeration. Soup was stored at different time (4 and 8 h), temperature (4°C, 25°C, and 30°C), and pressure (0.1, 100, and 150 MPa) conditions, to compare microbial loads and physicochemical parameters. HS resulted in similar (microbial growth inhibition) to better (microbial inactivation) results compared to refrigeration, leading to equal and lower microbial loads, respectively, at the end of storage. Lower/higher pressure (100 vs. 150 MPa) and shorter/longer storage times (4 vs. 8 h) resulted in more pronounced microbial growth inhibition/microbial inactivation. Aerobic mesophiles showed less susceptibility to HS, compared to Enterobacteriaceae and yeast and molds. HS maintained generally the physicochemical parameters at values similar to refrigeration. Thus, HS with no need for temperature control throughout storage and so basically energetically costless, is a potential alternative to refrigeration.