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Sobre

Sobre

Colaboro no INESCTEC desde 2014, onde me encontro integrado no CAP | Centre for Applied Photonics. Como Químico de formação, tenho uma formação e experiência extensas em síntese, caracterização e (numa longa lista de) diversas técnicas laboratoriais, entre as quais as de determinação de propriedades fotofísicas. A minha experiência começou numa área mais focada na bioquímica com estudos relacionados com a saúde, com aplicações de suplementação animal para melhoria de propriedades e posteriormente com métodos de valorização de sub-produtos de indústria primária. No âmbito do 7th FP da UE (SNIFFER) ajudei no desenvolvimento de uma rede inteligente capaz de detectar ameaças tanto na cadeia alimentar como na prevenção de (bio)terrorismo. Foram desenvolvidos sensores bem como líquidos iónicos com diferentes propriedades, passíveis de serem usados como "pontes" a outros sensores ou estruturas sensitivas, ou de agirem como sensores eles próprios. No âmbito do CORAL, desenvolvi sensores para detecção de espécies químicas em meio aquoso (NO3-, NO2- e PO4-), com vista a criar condições para sustentabilidade social e económica na exploração marinha. Desenvolvi e ajudei a desenvolver o protótipo que resultou do projecto AGRINUPES que visava criar condições de sustentabilidade na exploração agrícola, nomeadamente através do uso sustentado de água e nutrientes; pelo desenvolvimento de tecnologia sensitiva capaz de determinar a sua concentração "in situ", desta forma assegurando uma fertilização adequada, promovendo economia ecológica e financeira. Actualmente encontro-me enquadrado no Smart Fertilizers, um projecto de Agricultura 4.0, que visa desenvolver espalhadores e cisternas inteligentes, com vista ao aumento da eficiência da operação de fertilização, para melhorias operacionais e competitivas.

Tópicos
de interesse
Detalhes

Detalhes

004
Publicações

2021

Antimicrobial Activity of Myrtus communis L. and Rosmarinus officinalis L. Essential Oils against Listeria monocytogenes in Cheese

Autores
Saraiva, C; Silva, AC; Garcia Diez, J; Cenci Goga, B; Grispoldi, L; Silva, AF; Almeida, JM;

Publicação
FOODS

Abstract
Listeria monocytogenes has been referred to as a concern microorganism in cheese making due to its ability to survive and grow in a wide range of environmental conditions, such as refrigeration temperatures, low pH and high salt concentration at the end of the production process. Since cheese may be a potential hazard for consumers, especially high-risk consumers (e.g., pregnant, young children, the elderly, people with medical conditions), efforts of the dairy industry have been aimed at investigating new conservation techniques based on natural additives to meet consumers' demands on less processed foods without compromising the food safety. Thus, the aim of this study was to evaluate the efficacy of Myrtus communis L. (myrtle) and Rosmarinus officinalis L. (rosemary) essential oils (EO) against Listeria monocytogenes ATCC 679 spiked in sheep cheese before ripening. After the cheesemaking process, the samples were stored at 8 degrees C for 2 h, 1 d, 3 d, 14 d and 28 d. The composition of EO was identified by gas chromatography-mass spectrometry (GC-MS) analysis. Constituents such as 1,8-cineole, limonene, methyl-eugenol, alpha-pinene, alpha-terpineol, alpha-terpinolene and beta-pinene were present in both EO, accounting for 44.61% and 39.76% from the total of chemical compounds identified for myrtle and rosemary EO, respectively. According to the chemical classification, both EO were mainly composed of monoterpenes. Minimum inhibitory concentration (MIC) against L. monocytogenes was obtained at 31.25 mu L/mL to myrtle EO and at 0.40 mu L/mL to rosemary EO. Then, cheeses were inoculated with L. monocytogenes (Ca. 6 log CFU/mL) and EO was added at MIC value. The addition of rosemary and myrtle EO displayed lower counts of L. monocytogenes (p < 0.01) (about 1-2 log CFU/g) during the ripening period compared to control samples. Ripening only influences (p < 0.001) the growth of L. monocytogenes in control samples. Since rosemary and myrtle EO do not exert any negative impact on the growth of native microflora (p > 0.05), their use as natural antimicrobial additives in cheese demonstrated a potential for dairy processors to assure safety against L. monocytogenes.

2020

Behavior of Listeria monocytogenes in beef Sous vide cooking with Salvia officinalis L. essential oil, during storage at different temperatures

Autores
Moura Alves, M; Gouveia, AR; de Almeida, JMMM; Monteiro Silva, F; Silva, JA; Saraiva, C;

Publicação
LWT

Abstract
This study aims to evaluate the effect of Salvia officinalis L. (sage) essential oil (EO) on behavior of L. monocytogenes ATCC679 inoculated in beef processed by Sous-vide cook-chill (SVCC) and stored at 2 or 8 °C during 28 days. Minimum inhibitory concentration (MIC) of L. monocytogenes was obtained with 31.3 µL/mL of EO. D values were determined for samples with EO (21'39?) and without EO (21'17?). Beef samples were inoculated with L. monocytogenes at a concentration of 1 × 108 CFU/mL and vacuum-packed after EO addition at MIC value. Three heat treatments (F) were applied to reduce 1-log10 (F1), 2-log10 (F2) and 3-log10 (F3). EO composition was identified by gas-chromatography mass-spectrometry analysis. The main compounds identified were ß-pinene (11.70%), camphor (8.21%), ß-thujene (7.82%), 1.8-cineole (5.19%), a-humulene (6.07%) and endoborneol (4.87%).A reduction of approximately 1 log (CFU/g) of L. monocytogenes was observed in EO samples, compared to control samples at 2 °C. At 8 °C, despite exponential development from day 14, lower L. monocytogenes counts were observed in EO samples. Data showed that sage EO can help to control L. monocytogenes growth. However a possibility of using sage as a natural preservative, must be combined with other agents to control microbial growth more effectively. © 2020 Elsevier Ltd

2019

Optical Sensing of Nitrogen, Phosphorus and Potassium: A Spectrophotometrical Approach Toward Smart Nutrient Deployment

Autores
Monteiro Silva, F; Jorge, PAS; Martins, RC;

Publicação
Chemosensors

Abstract
The feasibility of a compact, modular sensing system able to quantify the presence of nitrogen, phosphorus and potassium (NPK) in nutrient-containing fertilizer water was investigated. Direct UV-Vis spectroscopy combined with optical fibers were employed to design modular compact sensing systems able to record absorption spectra of nutrient solutions resulting from local producer samples. N, P, and K spectral interference was studied by mixtures of commercial fertilizer solutions to simulate real conditions in hydroponic productions. This study demonstrates that the use of bands for the quantification of nitrogen with linear or logarithmic regression models does not produce analytical grade calibrations. Furthermore, multivariate regression models, i.e., Partial Least Squares (PLS), which consider specimens interference, perform poorly for low absorbance nutrients. The high interference present in the spectra has proven to be solved by an innovative self-learning artificial intelligence algorithm that is able to find interference modes among a spectral database to produce consistent predictions. By correctly modeling the existing interferences, analytical grade quantification of N, P, and K has proven feasible. The results of this work open the possibility of real-time NPK monitoring in Micro-Irrigation Systems.

2018

Quantification of Ethanol Concentration in Gasoline Using Cuprous Oxide Coated Long Period Fiber Gratings

Autores
Monteiro Silva, F; Santos, JL; Marques Martins de Almeida, JMMM; Coelho, L;

Publicação
IEEE Sensors Journal

Abstract

2017

The Antimicrobial Effect of Essential Oils Against Listeria monocytogenes in Sous vide Cook-Chill Beef During Storage

Autores
Gouveia, AR; Alves, M; de Almeida, JMMM; Monteiro Silva, F; Gonzalez Aguilar, G; Silva, JA; Saraiva, C;

Publicação
Journal of Food Processing and Preservation

Abstract
Sous vide cook-chill (SVCC) is characterized by vacuum-packaging raw or partially prepared foods before pasteurization, followed by rapid chilling and storage below 3C. The application of essential oils (EOs) to food products is a suitable strategy to control pathogens and to extend their shelf life by reducing microbial levels and oxidative processes. The aim of this study was to evaluate the efficacy of Rosmarinus officinalis L. (rosemary) and Thymus vulgaris L. (thyme) EOs against Listeria monocytogenes ATCC 679, inoculated in beef processed by SVCC stored at 2 and 8C for 1, 2, 3, 7, 14, 21 and 28 days. The composition of EOs was identified by gas chromatography-mass spectrometry analysis. The main compounds identified in rosemary EO were eucalyptol (13.05%), camphor (8.93%), verbenone (8.58%), endo-borneol (7.87%) and a-pinene (6.78%) and in thyme EO were linalool (18.18%), thymol (7.48%), limonene (6.49%), endo-borneol (5.86%) and terpinen-4-ol (5.66%). Using the minimum inhibitory concentration (MIC) method, L. monocytogenes was inhibited at 3.9 µL/mL to thyme EO and at 62.5 µL/mL to rosemary EO. Beef samples of M. longissimus thoracis et lumborum were packaged in bags, inoculated and one of each EO was added at MIC values. Bags were vacuum-sealed and samples were processed at 55C/65 min for 3 log10 CFU/g reduction. A reduction of the counts of L. monocytogenes was observed in all samples at 2C. At 8C counts of L. monocytogenes were almost similar in control samples and those with thyme EO with an increase of the microbial counts since day 7. Inversely, counts of L. monocytogenes in beef samples with rosemary EO stored at 2 and 8C decreased about 2 log10 CFU. These results support the possibility of using rosemary EO as natural preservative due to its antimicrobial effect against L. monocytogenes. Also, our results confirm that an adequate chilling storage is essential to guarantee the safety of SVCC product regarding L. monocytogenes to avoid foodborne outbreaks. Practical Applications: Results support the possibility of addition of EO of rosemary as a natural preservative to reduce L. monocytogenes counts. Also, an adequate chilling storage for maintaining this pathogen at acceptable levels is of paramount importance in view of preventing food borne diseases. © 2016 Wiley Periodicals, Inc.