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Publicações

Publicações por Filipe Monteiro Silva

2016

Antimicrobial effect of essential oils of Laurus nobilis L. and Rosmarinus officinallis L. on shelf-life of minced "Maronesa" beef stored under different packaging conditions

Autores
Vilela, J; Martins, D; Monteiro Silva, F; Gonzalez Aguilar, G; de Almeida, JMMM; Saraiva, C;

Publicação
FOOD PACKAGING AND SHELF LIFE

Abstract
The aim of this study was to evaluate the effect of essential oils (EOs) of plants naturally occurring in northern Portugal on the spoilage of fresh Maronesa beef burgers stored at 2 and 8 degrees C under different packaging conditions. EOs were obtained from dried leaves of laurel (Laurus Nobilis L.) and rosemary (Rosmarinus officinallis L.) by hydro-distillation using a Clevenger-type apparatus. Analysis of volatile composition of essential oils of rosemary and laurel was achieved by Gas Chromatography-Mass Spectrometry (GC-MS) and Gas Chromatography-Thermal Conductivity Detection (GC-TCD) resulting in the detection of 95.8% and 89.4% of its compounds, respectively. Fresh beef (semitendinosus and semimembranosus) of DOP-Maronesa breed (males; n = 4) were obtained from local market and transported to the laboratory. Samples were stored at 2 and 8 degrees C in two different conditions: aerobiosis (A) and vacuum (V) and analyzed at 0,1, 2, 3, 5, 7,10,14, 21 and 28 days for Lactic acid bacteria (LAB), Enterobacteriaceae, Pseudomonas spp., Fungi, Total mesophilic (TM) and psychrotrophic (TP), color (L*a*b*) and pH. Laurel was the most effective EO keeping pH from increasing. Coordinates L* and a* were higher on samples containing laurel EO for both A and V packaging. Laurel also showed better effect in reducing microbiologic counts in samples packed in A at both 2 and 8 degrees C and packed in V at 8 degrees C. Rosemary was effective in reducing microbial counts on all V samples stored at 2 degrees C. This study allows to conclude that Laurel EO has significant effect in shelf-life, maintaining fresh beef color.

2014

Effects of the dietary incorporation of olive leaves on growth performance, digestibility, blood parameters and meat quality of growing pigs

Autores
Paiva Martins, F; Ribeirinha, T; Silva, A; Goncalves, R; Pinheiro, V; Mourao, JL; Outor Monteiro, D;

Publicação
JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE

Abstract
BACKGROUND: In a preliminary study the oxidative stability and tocopherol content of pork meat were shown to be improved by olive leaf (OL) feed supplementation at 50 and 100 g kg(-1). However, growth performance was affected negatively. Therefore the objective of the present study was to assess the influence of OL supplementation at a lower level on feed digestibility, growth performance and meat quality. RESULTS: Pigs were fed a basal diet (control), a basal diet with 25 g OL kg(-1) (OL2.5) or a basal diet with 50 g OL kg(-1) (OL5). The incorporation of OL significantly decreased growth rates (P = 0.010) and backfat thickness (P = 0.035) and increased feed/gain ratio (P = 0.032) in the OL5 group. Feed/gain ratio increased more for females (P = 0.001). The incorporation of OL decreased the crude fat (P = 0.006) and protein (P = 0.037) digestibility of both OL diets. Nevertheless, OL was effective in increasing the tocopherol content of meat (P = 0.009). However, meat from pigs fed the OL diets showed similar conjugated diene content, pH and colour parameters to that from pigs fed the control diet, even after 6 days of storage at 4 degrees C. CONCLUSION: The data indicate that olive leaves may be included in pig diets at 25 g kg(-1) in order to improve the tocopherol content of meat without excessively compromising growth performance. (C) 2014 Society of Chemical Industry

2013

Protective Activity of Hydroxytyrosol Metabolites on Erythrocyte Oxidative-Induced Hemolysis

Autores
Paiva Martins, F; Silva, A; Almeida, V; Carvalheira, M; Serra, C; Rodrigues Borges, JE; Fernandes, J; Belo, L; Santos Silva, A;

Publicação
JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY

Abstract
The capacity of important hydroxytyrosol metabolites (homovanillyl alcohol, hydroxytyrosol acetate, homovanillyl alcohol acetate, hydroxytyrosol 3' and 4'-O-glucuronides, and homovanillyl alcohol 4'-O-glucuronide) to protect red blood cells (RBCs) from oxidative injury induced by the radical initiator 2,2'-azo-bis(2-amidinopropane) dihydrochloride (AAPH) or by the natural radical initiator H2O2 was evaluated. In the presence of AAPH, all compounds showed to protect RBCs from hemolysis in a dose-dependent manner, exccept for the homovanillyl alcohol glucuronide, with the order of activity being at 20 mu M hydroxytyrosol > hydroxytyrosol glucuronides = hydroxytyrosol acetate = homovanillyl alcohol = homovanillyl acetate > homovanillyl alcohol glucuronide. At 10 mu M, hydroxytyrosol, hydroxytyrosol acetate, and hydroxytyrosol glucuronides still protected hemoglobine from oxidation and from morphological RBC changes. In the presence of H2O2, hydroxytyrosol showed to significantly protect RBCs from oxidative hemolysis in a dose-dependent manner, but the hydroxytyrosol glucuronides showed only a limited protection that was independent of the concentration used.

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

2016

Involvement of endothelium in the vasorelaxant effects of 3,4-DHPEA-EA and 3,4-DHPEA-EDA, two major functional bioactives in olive oil

Autores
Segade, M; Bermejo, R; Silva, A; Paiva Martins, F; Gil Longo, J; Campos Toimil, M;

Publicação
JOURNAL OF FUNCTIONAL FOODS

Abstract
The olive oil polyphenols 3,4-DHPEA-EA and 3,4-DHPEA-EDA displayed an endothelium dependent vasorelaxant effect in rat aorta, starting at similar to 1 mu M and abolished by N-G-nitro-L-arginine (L-NA) or N-acetylcysteine, and an endothelium-independent vasorelaxant effect, starting at similar to 10 mu M. Hydroxytyrosol only presented an endothelium-independent effect at 100 mu M. DHPEA-EA and 3,4-DHPEA-EDA, but not hydroxytyrosol, also increased NO generation within endothelial cells. At higher concentrations, the three compounds reduced argininevasopressin-induced increase of cytosolic Ca2+ concentration ([Ca2+](c)) in vascular myocytes. By UV-visible spectroscopy, we found that these polyphenols undergo autoxidative processes in organ-bath conditions. Thus, 3,4-DHPEA-EA and 3,4-DHPEA-EDA have an endothelium-dependent vasorelaxant effect caused by an enhanced NO production, probably through a redox mechanism within endothelial cells and an endothelium-independent vasorelaxant effect mediated by a reduction of agonist-induced [Ca2+](c) increase in vascular myocytes. Bearing in mind the plasmatic concentrations of these polyphenols following dietary intake of olive oil, these effects could modulate vascular tone in vivo.

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.

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