DFIS - Artigo de Conferência em Revista Científica não Indexada
URI permanente para esta coleção:
Navegar
Entradas recentes
Item Acesso Aberto Study of essential oil of Rosmarinus officinalis L. in different maturation stages by mass spectrometry (GC-MS)2016 - Almeida, José Manuel Marques Martins de; Silva, Filipe Monteiro; Ribeiro, Miguel; Silva, Ana Catarina; González-Aguilar, Gerardo; Saraiva, Cristina Maria TeixeiraItem Acesso Aberto Spectroscopic methodologies for fresh food authentication2016 - Almeida, José Manuel Marques Martins de; Moreira, Maria João; Saraiva, Cristina Maria TeixeiraThe increasing occurrence of fraud in foodstuffs points to the need to the identification of species as a part of authentication. Particularly, meat and fish can be targets of adulteration, such as the substitution or removal of ingredients, addition of proteins from various origins and the addition of food additives, contributing to increased financial profits [1]. Researchers have applied various analytical techniques for the detection of fraud in foodstuffs. The protein, DNA and PCR based techniques have become increasingly important. However, these methods are laborious, expensive, destructive and require sophisticated laboratory procedures. Moreover, they are not suitable for real-time applications. Nondestructive technologies for authentication and traceability of foodstuffs, including nuclear magnetic resonance (NMR) imaging, fluorescence (FS), near infrared (NIR), mid infrared (MIR) and Raman (RS) spectroscopy coupled with Fourier transform (FT) and multispectral (MS) and hyperspectral (HIS) imaging, are emerging technologies [2]. Combined with multivariate statistical methods, NIR, MIR, RAMAN are well established techniques that were largely applied in the authentication of foodstuffs. These technologies are simple, non-invasive, low cost, allow real time analysis, require small samples and no further sample preparation is necessary. The MS, HIS and spatial multispectral analysis convenient for food inspection. They are able to analyzed larger number of samples simultaneously. However, the high initial costs and difficulties in data acquisition have limited the use of this real-time technology. In this work a revision of the state of the art on spectroscopic methods for food authentication will be presented as well as the experimental results obtained in the study of adulteration of fallow deer (Dama dama) with goat (Capra aegagrus hircus).Item Acesso Aberto Shelf-life of fresh salmon (Salmo Salar) with lemon juice stored at normal and abusive temperatures2016 - Saraiva, Cristina Maria Teixeira; Vasconcelos, Helena; Almeida, José Manuel Marques Martins deItem Acesso Aberto Shelf-life of salmon stored under modified atmospheres2014 - Vasconcelos, Helena; Saraiva, Cristina Maria Teixeira; Almeida, José Manuel Marques Martins deItem Acesso Aberto Effect of storage temperature abusive and type of packaging in sanitary safety of fresh salmon2013 - Vasconcelos, Helena; Almeida, José Manuel Marques Martins de; Saraiva, Cristina Maria TeixeiraItem Acesso Aberto Discrimination and characterization of maturation stages of extra virgin olive oils using FTIR in tandem with chemometrics2013 - Gouvinhas, Irene Pereira; Almeida, José Manuel Marques Martins de; Barros, Ana Isabel Ramos Novo Amorim deItem Acesso Aberto Study of optical fiber sensor tip based on surface plasmon resonance2013 - Almeida, José Manuel Marques Martins de; Coelho, Luís; André, Paulo; Santos, José Luís; Viegas, Diana; R. A. S. FerreiraOptical fiber sensors based on surface plasmon resonance (SPR) has been widely studied for the last 20 years using several configurations mostly with multimode optical fibers combining large cores and plastic claddings. Sensors based on this physical phenomenon present very high sensitivity to the refractive index variations. SPR can be defined as a charge-density oscillation that in certain conditions exist at the interface of two media excited by the evanescent wave of the propagated light. The proposal is a SPR sensor in a single mode fiber end chemically etched by emersion in a 48% hydrofluoric acid solution with a Titanium mirror. The result is a tip on a single mode fiber with the cladding removed and a mirror perpendicular to the light path at the end, allowing operation in reflection mode. Although only 9 m in diameter the sensor has high robustness. A set of thin films were then deposited around the cylindrical fibers. The etched region was coated with 2nm of Ti to improve the adhesion of a 20nm thick gold film followed by a 100nm thick layer of a dielectric material. Thin metal and dielectric films were produced by electron beam evaporation. The equipment is fitted with a homemade rotary system to produce homogeneous films around the cylindrical fibers. It was found that a velocity of around 5rpm improves the film homogeneity. Simulations were performed in order to determine the optimal thicknesses of the thin films to create a resonance dip in the 1550nm wavelength.Item Acesso Aberto Caracterização da fração fenólica de resíduos de lagares de azeite extraída com acetato de etilo, por métodos químicos, cromatográficos e espectroscópicos2014 - Cardoso, Ricardo Micael de Oliveira; Matos, Patrícia Raquel da Silva; Marinho, Carla Maria Alves Quintelas do Amaral; Almeida, José Manuel Marques Martins deItem Acesso Aberto Padrão deteriorativo de mini-hamburgueres de carne de Gamo (Dama dama) armazenados a 3ºC em aerobiose2014 - Nascimento, Patricia; Saraiva, Cristina Maria Teixeira; Moreira, Maria João; Silva, Ana Catarina; Almeida, José Manuel Marques Martins deItem Acesso Aberto Avaliação da fração fenólica extraída com metanol de resíduos de lagares de azeite por métodos químicos, cromatográficos e espectroscópicos2014 - Matos, Patrícia Raquel da Silva; Cardoso, Ricardo Micael de Oliveira; Almeida, José Manuel Marques Martins de; Marinho, Carla Maria Alves Quintelas do AmaralItem Acesso Aberto Estudo da adulteração de carnes frescas por espectroscopia de infravermelhos e análise quimiométrica2014 - Silva, Ana Catarina; Saraiva, Cristina Maria Teixeira; Moreira, Maria João; Nascimento, Patricia; Almeida, José Manuel Marques Martins deItem Acesso Aberto Aplicação da espectroscopia de infravermelhos na diferenciação da deterioração de carnes de caça2014 - Saraiva, Cristina Maria Teixeira; Moreira, Maria João; Silva, Ana Catarina; Nascimento, Patricia; Almeida, José Manuel Marques Martins deItem Acesso Aberto Efeito Antimicrobiano de Óleos Essenciais de Laurus Nobilis L. e Rosmarinus Officinallis L. no Tempo de Vida Útil de Hambúrgueres de carne “Maronesa” Armazenados Sob Diferentes Condições2015 - Vilela, Joana; Martins, Dirce; Pires, Patricia; Saraiva, Cristina Maria Teixeira; Almeida, José Manuel Marques Martins deItem Acesso Aberto Coated optical fibres for sensing at INESC TEC2015 - Almeida, José Manuel Marques Martins de; Coelho, Luis; Santos, José Luís; Viegas, DianaOptical fibre sensors are playing na important role in themodern society. Some of the greatest issues of a sensor are its sensitivity, resolution, accuracy and multiplexing capabilities. Optical fibre devices with the appropriating coating can fulfil some of these requirements. Surface plasmon resonance in fibres can provide sensitivities up to 5000 nm/RIU in a wide range of refractive índex while long period gratings can be produced and coated in a way to reach more than 8000 nm/RIU in a narrow refractive index band and for values higher than the cladding.Item Acesso Aberto Antimicrobial effect of essential oils of laurus nobilis l. and rosmarinus officinallis l. on shelf-life of minced “maronesa” beef stored under different packaging conditions2015 - Vilela, Joana; Martins, Dirce; Pires, Patricia; Almeida, José Manuel Marques Martins de; Saraiva, Cristina Maria TeixeiraEO’s can be used as food preservatives to improve food hygiene, reducing the microbiota development and enhancing shelf-life of beef. The aim of this study was to evaluate the effect of essential oils (EO) of plants and fruits naturally occurring in northern Portugal on the spoilage of fresh Maronesa beef burgers stored at 2 and 8°C, under different packaging conditions. To produce EOs, leaves of laurel (Laurus nobilis L.) and rosemary (Rosmarinus officinallis L.) were obtained from the botanical garden of UTAD. The dried leaves were submitted to hydrodistillation using a Clevenger-type apparatus. Fresh beef (semitendinosus and semimembranosus) of DOP-Maronesa breed (males; n=4) were obtained from local market and transported to lab. After cut and minced, 20 g samples were individually packed in duplicate in two different conditions: air (A) and vacuum (V) with and without one EO. Samples were stored at 2 and 8°C and analysed immediately at 0,1,2,3,5,7,10,14,21,28 days for microbiological, colour (L*a*b*), pH and sensory analysis. Sensory panellists evaluated each sample after 60 min at each storage end time for colour and spoiled odour. The microorganisms analysed were Lactic acid bacteria (LAB), Enterobacteriaceae, Pseudomonas spp., Fungi, total mesophilic (TM) and psicrothrophic (TP). The most effective EO keeping pH from increase was laurel’s. Concerning colour, L* coordinate was higher on samples containing Laurel’s EO for both A and V; a* was higher for all samples with laurel’s EO, corresponding also the highest scores of red colour in sensory analysis. Laurel’s EO is the one that shows better effect reducing LAB, Enterobacteriaceae, Pseudomonas spp., Fungi, TM and TP counts in samples packed in A (2, 8ºC) and V at 8ºC. Rosemary was effective reducing counts on all V 2ºC samples. This study allows to conclude that Laurel’s EO has significant effect maintaining fresh beef colour.Item Acesso Aberto Antibacterial activity of Myrtus communis L. essential oil on pathogenic and spoilage microbiota2015 - Martins, Dirce; Vilela, Joana; Alfredo Aires; Almeida, José Manuel Marques Martins de; Silva, Filipe Monteiro; González-Aguilar, Gerardo; Saraiva, Cristina Maria TeixeiraItem Acesso Aberto Study of deterioration of minced beef of portuguese maronesa breed stored under various atmospheres and temperatures2015 - Saraiva, Cristina Maria Teixeira; Vilela, Joana; Martins, Dirce; Pires, Patricia; Almeida, José Manuel Marques Martins deItem Acesso Aberto Study of deterioration of minced beef of portuguese maronesa breed stored under2016-04-01 - Saraiva, Cristina; Almeida, José Manuel Marques Martins deItem Acesso Aberto Advances in the detection of fraudulent frsh game meat using mid infrared spectroscopy2017 - Maria João Moreira; Cristina Saraiva; Almeida, José Manuel Marques Martins deItem Acesso Aberto Study of essential oil of Rosmarinus officinalis L. in different maturation stages by mass spectrometry (GC-MS)2016 - Almeida, José Manuel Marques Martins De; Silva, Filipe Monteiro; Ribeiro, Miguel; Silva, Ana Catarina; Saraiva, Cristina Maria Teixeira