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- Study of the aerodynamic sealing of a cold store – Experimental and numerical approachesPublication . Goncalves, J.C.; Costa, J.J.; Figueiredo, A.R.; Lopes, A.M.G.An experimental study was conducted in a laboratory scale model in order to characterize the airflow generated by an air curtain device (ACD) on the aerodynamic sealing of refrigerated spaces. The laboratory scale model consists of two similar adjacent rooms connected by a door over which the ACD device was installed. The tracer gas technique was used to calculate the sealing effect achieved with the air curtain at different jet velocities. A three-dimensional numerical model was also developed to simulate the heat and mass transfer phenomena, as well as the aerodynamic sealing performance of an ACD. The numerical study was carried out using a commercial CFD code (ANSYS-CFX®) and the turbulence effects were approached by two different turbulence models (k–ε and k–ω SST). The experimental and numerical results show a good agreement for validation purposes. No significant differences were found in the results obtained with the two turbulence models, although the k–ω SST model seems to be more appropriate for the simulations. The existence of an optimum discharge air jet velocity was confirmed. The results also indicate that the air curtain is more efficient in reducing the mass transfer than the energy flow rate across the doorway.
- Flores comestíveis como fonte de compostos bioativos com atividade antioxidantePublication . Guiné, Raquel P. F.; Ferrão, Ana Cristina; Correia, Paula; Goncalves, J. C.; Gonçalves, Fernando JorgeExistem muitas espécies vegetais utilizadas na gastronomia, entre as quais as flores comestíveis (FC). Para que uma flor seja considerada comestível ela deve ser não tóxica, inócua e ter propriedades nutricionais. Historicamente, as FC têm sido usadas para fins culinários há séculos em várias partes do mundo, como Ásia, Grécia antiga, Roma e também na França medieval. Adicionalmente, constituem uma boa fonte de compostos bioativos, nomeadamente fitoquímicos, associados a várias propriedades farmacológicas, destacando a proteção contra doenças cardiovasculares e os efeitos ansiolíticos, anticancerígenos, antidiabéticos, anti-inflamatórios, antioxidantes, diuréticos, imunomoduladores e antimicrobianos. Recentemente, as FC têm despertado crescente interesse, devido às suas propriedades estéticas e organoléticas, bem como potenciais benefícios para a saúde, relacionados com a ocorrência de alguns compostos bioativos. Nesta medida, o objetivo do presente trabalho foi avaliar os teores de compostos fenólicos totais, antocianinas e flavonoides, bem como a atividade antioxidante num conjunto de FC. Para a análise foram obtidos extratos de onze espécies de FC que foram utilizados para a quantificação da composição fenólica e atividade antioxidante usando métodos espectrofotométricos. Dos resultados obtidos foi possível verificar que as rosas e cravos de coloração vermelha ou rosa se destacaram como contendo maiores teores de compostos fenólicos totais (18 a 27 mg EGA/g), e ainda maiores aportes de antocianinas (3 a 5 mg EC/g). Verificou-se ainda que eram também essas as FC com maior atividade antioxidante (12 a 16 mg ET/g). De destacar por fim o cravo vermelho como contendo maior quantidade de flavonoides (cerca de 18 mg EC/g). Em conclusão, verifica-se que as FC, para além das suas potencialidades gastronómicas, podem constituir um veículo para a ingestão de compostos com efeitos benéficos para a saúde, nomeadamente no que respeita ao combate aos radicais lives responsáveis pelo envelhecimento celular.
- Knowledge about consumption of milk: Study involving consumers from two European Countries – France and PortugalPublication . Bréjon, Marius; Tavares, Francisca; Florença, Sofia De Guiné E; C. Goncalves, J.; Barroca, Maria João; Guiné, RaquelMilk assumes a pivotal role in human nutrition from early stages of life, although when going into adulthood the consumption habits can vary according to different perceptions from the consumer or even due to the presence of some intolerances. In this context, this research focuses on the consumption knowledge about the composition and nutritional value of milk and its effect on human health. The objective was to investigate how informed are the French and Portuguese participants and detect similarities or differences according to the country. For this purpose, a questionnaire survey was set up to recruit participants from two countries: France and Portugal. The total number of participants was 543, of which 333 were French and 210 were Portuguese. For treatment of data basic statistics and tests were used to compare the results between the two countries, using the software SPSS. The results showed significant differences between the two countries in what concerns the participant’s knowledge about milk composition and nutritive value and also the effects of milk on human health. From the 13 items used to assess knowledge about composition and nutritive value of milk, significant differences were found between countries for six of them. Regarding the ten items used to evaluate the effects of milk on human health, significant differences were found for seven of them. As so, the knowledge about the effects on human health are more differentiated between the participants from France and Portugal, than the knowledge about the milk composition. Factor analysis showed six groups of questions, with good internal reliability (values of alpha varying from 0.707 to 0.825). It is concluded that participants from different countries, exposed to different environments (societal, political, or educational) can have different perceptions about milk and its effects on health.
- Food safety in portuguese Companies in Covid-19 Pandemic ContextPublication . C. Goncalves, J.; Guiné, Raquel P. F.; Correia, Paula; Tomasevic, I.; Djekic, I.
- Consumer Knowledge about Dietary Relevance of Fruits and Vegetables: A Study Involving Participants from Portugal and FrancePublication . Le Turc, Nolwenn; Silva, Ana Jaquelina; Florença, Sofia De Guiné E; Raposo, António; C. Goncalves, J.; Lima, Maria João; Teixeira de Lemos, Edite; Guiné, RaquelFruits and vegetables are recommended as low-calorie foods that contribute to the proper intake of necessary micronutrients, macronutrients, and bioactive compounds with health benefits. However, the recommendations for the dietary intake of these foods fail to be attained in most European countries. For this reason, promoting more knowledge about the health effects of fruits and vegetables is essential to decrease the incidence of chronic diseases. This study was conducted to investigate the knowledge of the health benefits of fruits and vegetables among the population of Portugal and France. The present work involved a questionnaire survey of 639 participants (257 from Portugal and 382 from France). The results revealed that most participants were young females (68.9%) with good education (76%) and an average weight range. They consumed a varied diet (57%) but had body dissatisfaction (63.2%). The respondents had good knowledge about the health effects of fruits and vegetables. However, the French population knew more about the theme than the Portuguese. Portuguese individuals were more likely to have incomplete information. Gender and education significantly influenced knowledge levels, with females and highly educated individuals demonstrating greater understanding. Dissatisfaction with body weight drives individuals to seek nutrition information. This investigation enhances our comprehension of the factors that affect knowledge of vegetable and fruit consumption among young adults in Portugal and France. Moreover, it highlights the importance of implementing focused educational programs to enhance nutrition literacy, particularly for less-aware demographic groups. Going forward, a more in-depth analysis of these factors could assist in creating more efficient strategies to encourage healthier dietary habits and improve nutrition literacy among these communities.
- Angular variation of fire rate of spreadPublication . André, Jorge C. S.; Goncalves, J. C.; Vaz, Gilberto C.; Viegas, Domingos X.Laboratory fire tests were performed in still air, for variable inclinations (10°, 15°) and fuel bed dimensions (1.28 × 2.50–3.0 × 4.6 m2), with homogeneous fuel beds of pine needles and pine wood excelsior. The fire ignition was made at a point, along a closed line with no fuel inside and along a straight edge of the fuel bed. The tests were recorded with an infrared camera and various techniques were developed to implement direct and indirect empirical methods of construction of the ‘orientation function’ of the fire in the given fuel bed and ambient conditions, showing how the rate of spread of a steady straight fire front depends on its orientation on the terrain. The direct method uses a set of straight fire fronts with various orientations whereas the indirect method uses essentially a point ignited fire front. Contrary to what is assumed in BehavePlus model, the orientation function is observed to depend significantly on the properties of the fuel bed. In all tests with closed fire fronts, the full steadiness required by the indirect method was not achieved (namely, at the head of the front), although, for slope angle of 10°, the corresponding errors induced on the orientation function were small.
- Fruit and vegetable consumption: Study involving Portuguese and French consumersPublication . LE TURC, Nolwenn; Silva, Ana Isabel; Florença, Sofia De Guiné E; C. Goncalves, J.; Lemos, Edite Teixeira de; Lima, M. J. Reis; Guiné, RaquelThe regular consumption of vegetables and fruits has been indicated as part of a healthy diet. They are considered healthy foods because they are sources of vitamins, minerals, and fibre. Adequate intake of these foods can reduce the risk of certain chronic diseases, like cardiovascular disease, diabetes, obesity, and various types of cancer. The objective of the present study was to determine the consumption habits of vegetables and fruits in two different countries, Portugal and France. For this descriptive study, it was used a questionnaire survey, applied to individuals over 18 years old and carried out through the internet, being disseminated on social networks and by email. The sample was constituted by 640 participants (257 from Portugal and 383 from France). Statistical tools were used for the treatment of data, like the T-Test and chi-square test utilised to compare the results between Portuguese and French consumers. The results showed that the Portuguese eat out more often than the French. Portuguese and French like vegetables equally but the French eat more vegetables and fruit per week on average than the Portuguese. The French like soup as much as the Portuguese but the Portuguese eat soup more regularly than the French and prefer soup with cut pieces, unlike the French which prefer soup with grounded vegetables. The global consumption of vegetables and fruits is low in both countries and should be increased, most especially in Portugal, where the consumption is lower. In conclusion, despite some differences found across consumers according to country, the consumption of these foods is still below the recommendations of the World Health Organisation, and therefore, some more actions are necessary to incentivise a higher consumption of fruits and vegetables as part of a healthy lifestyle.
- Flour from drone broods: A viable alternative?Publication . Correia, Paula; Vouga, C; Coelho, Catarina; Costa, Cristina Amaro Da; Guiné, Raquel P. F.; Gonçalves, Fernando Jorge; C. Goncalves, J.
- Numerical study of the optimal nozzle width and jet orientation in a downward blowing air curtainPublication . C. Goncalves, J.; Costa, José Joaquim Da; Gameiro Lopes, Antonio; Figueiredo, A. RuiThis paper presents a numerical study of the performance of an air curtain device (ACD) installed on top of the access door of a refrigerated room, aiming to quantify the influence of some parameters (nozzle width, initial orientation and discharge velocity of the jet) towards the maximization of the sealing effect. For this purpose, a numerical model was developed to simulate the turbulent non-isothermal 3D airflow generated by the ACD jet, focusing on the period after the door is opened. The situation when the ACD is switched off is taken as the reference for the performance evaluation. The results allow identifying an optimum jet nozzle width corresponding to maximum sealing efficiency and lower jet airflow rate (lower energy consumption in the air curtain operation). For the present conditions (ACD installed outside the refrigerated room), the sealing efficiency is highest with the ACD oriented vertically and is practically unaffected if the jet discharge is directed towards the warmer space. On the contrary, a jet discharged towards the cooler space is very detrimental to the ACD sealing effect
- Analysis of the air infiltration through the doorway of a refrigerated room using different approachesPublication . Gonçalves, J. C.; Costa, J.J.; Lopes, A.M.G.This paper presents the study of the air movement through the doorway of a refrigerated room, using both numerical and experimental approaches. Firstly, a comparison is made between the experimentally observed infiltration rates and the predictions by seven empirical models. For different test conditions of the specific laboratory configuration under analysis (a refrigerated room at laboratory scale), the infiltration rate was measured using the tracer gas technique. A three-dimensional numerical model was developed to simulate the heat and mass transfer phenomena, using a commercial CFD code (ANSYS-CFX®). For the simulations, turbulence effects were taken into account using the k- SST turbulence model. CFD results showed a good agreement with experimental data, confirming that the numerical model is appropriate to evaluate this physical phenomenon. The experimental and numerical results showed that the neutral flow level is located above the doorway mid-height and that the maximum airflow velocity occurs near the doorposts. Results also evidenced that, although most of the empirical models tend to overestimate the infiltration rate, some of them present a quite good prediction ability. Measurements in a real scale refrigerated room confirmed the trend obtained in the laboratory installation.