Associate Laboratory for Sustainability and Tecnology in Mountain Regions

Funder

Organizational Unit

Publications

Nutraceuticals and dietary supplements: balancing out the pros and cons

Publication . Fernandes, Filipa Alexandra; Carocho, Márcio; Prieto Lage, Miguel A.; Barros, Lillian; Ferreira, Isabel C.F.R.; Heleno, Sandrina A.

While the market is full of different dietary supplements, in most countries, legislation is clear and strict towards these products, with severe limitations on their health claims. Overall, the claims cannot go beyond the consumption of a said supplement will contribute to a healthy diet. Thus, the supplement industry has been reacting and changing their approach to consumers. One change is the considerable growth of the nutraceutical market, which provides naturally produced products, with low processing and close to no claims on the label. The marketing of this industry shifts from claiming several benefits on the label (dietary supplements) to relying on the knowledge of consumers towards the benefits of minimally processed foods filled with natural products (nutraceuticals). This review focuses on the difference between these two products, their consumption patterns, forms of presentation, explaining what makes them different, their changes through time, and their most notable ingredients, basically balancing out their pros and cons.

2024Journal article

Restricted access

An Over-Actuated Hexacopter Tilt-Rotor UAV Prototype for Agriculture of Precision: Modeling and Control

Publication . Pimentel, Gabriel Oliveira; Santos, Murillo F. dos; Lima, José; Mercorelli, Paolo; Fernandes, Fernanda Mara

This paper focuses on the modeling, control, and simulation of an over-actuated hexacopter tilt-rotor (HTR). This configuration implies that two of the six actuators are independently tilted using servomotors, which provide high maneuverability and reliability. This approach is predicted to maintain zero pitch throughout the trajectory and is expected to improve the aircraft’s steering accuracy. This arrangement is particularly beneficial for precision agriculture (PA) applications where accurate monitoring and management of crops are critical. The enhanced maneuverability allows for precise navigation in complex vineyard environments, enabling the unmanned aerial vehicle (UAV) to perform tasks such as aerial imaging and crop health monitoring. The employed control architecture consists of cascaded proportional (P)-proportional, integral and derivative (PID) controllers using the successive loop closure (SLC) method on the five controlled degrees of freedom (DoFs). Simulated results using Gazebo demonstrate that the HTR achieves stability and maneuverability throughout the flight path, significantly improving precision agriculture practices. Furthermore, a comparison of the HTR with a traditional hexacopter validates the proposed approach.

2025Journal article

Open access

Perceptions and expectations of African higher education students about bioeconomy

Publication . Ribeiro, Maria Isabel; Fernandes, Ana Isabel Ribeiro; Fernandes, António Pedro; Fernandes, António

Bioeconomy offers new approaches to dealing with environmental challenges, such as replacing fossil fuels with sustainable and renewable resources and fuels. So, knowing how African higher education students perceive Bioeconomy is important. To achieve this objective, an exploratory and quantitative study based on a convenience sample of 407 students was conducted. The data was collected using an adapted questionnaire and analyzed using descriptive statistics. The majority of students came from rural areas (88.0%), were female (56.’%), and were between 18 and 22 years old (52.3%). Students favor replacing fossil resources with renewable ones so that the transition to a sustainable Bioeconomy can be achieved (89.2%). The three main measures to be implemented if students were responsible for preparing a transformation plan for the Bioeconomy, are: (1) improvement of knowledge and information about Bioeconomy; (2) improving the participation of the population and companies in the transformation process; (3) developing of recycling and reuse of materials. Furthermore, the majority of students consider that the transition to the Bioeconomy could reduce the amount of plastic waste in the environment and oceans (67.1%), the loss of natural environments (55.4%), the emission of carbon (54.1%), species extinction (52.6%) and particle pollution (52.3%). Regarding students' perceptions about the beneficial contributions that Bioeconomy can provide, in economic, social, and environmental terms, students believe that Bioeconomy is capable of promoting major improvements, namely, creating new jobs (78.1%), achieving a more sustainable international development model (68.1%), improving access to new areas of research and education (64.6%), improving economic performance and regional and international competitiveness (63.6%), reducing dependence energy (58.7%) and ensuring the security and stability of the energy network (56.5%). This study also shows that students do not consider themselves adequately informed about pertinent topics related to the Bioeconomy since only around 27% reported being quite familiar with the sustainable development objectives defined by the United Nations. Furthermore, topics such as genetic engineering in agriculture, the cultivation of energy crops, and the digitalization of agriculture are only familiar to just over 10% of respondents. When asked which sources of information about the Bioeconomy they trust most, environmental and farmer organizations stand out positively, and national and local governments negatively. Regarding pro-environmental actions carried out by students in the last 12 months, the majority highlights the conscious purchases of regional food products (63.4%), neglecting other types of equally important actions, namely, the change in mobility behavior, the abandonment of packaged products, the use of renewable energy, the purchase of green products, among others. Finally, concerning interests and values, students believe that it is possible, by managing resources well, to avoid environmental catastrophes even though they realize that the environment is very fragile and that any human interference can result in devastation. Perhaps for this reason, the majority are not defenders of the free market and economic growth at the expense of the environment. There are gaps in understanding the advantages, visions, and topics associated with the Bioeconomy.

2024Conference object

Open access

Green Extraction Strategy Using Bio-Based Aqueous Biphasic Systems for Polyphenol Valorization from Grape By-Product

Publication . Dimitrijević, Aleksandra; Marić, Slađana; Jocić, Ana; Tekić, Danijela; Mušović, Jasmina; Amaral, Joana S.

Polyphenols are natural compounds with enhanced antioxidant properties. They are present in relatively high concentrations in fruit/vegetable by-products. Therefore, there is a need for the development of efficient and cost-effective methods for the separation and purification of these valuable compounds. Traditional extraction with organic solvents needs to be switched to novel methods that are more efficient, with reduced extraction times and low consumption of organic solvents. Aiming at developing sustainable processes for the separation and purification of phenolic compounds, we used three model compounds, namely resveratrol, quercetin, and gallic acid, to investigate ionic liquid-based aqueous biphasic systems (IL-ABSs) formed by cholinium-based IL in combination with polypropylene glycol with a molecular mass of 400 g/mol (PPG400). The ABS composition in the two-phase region was selected according to a previously determined phase diagram. Extraction studies indicated the preferential partition of resveratrol and quercetin toward the hydrophobic PPG-rich phase that is mainly dominated by its hydrophobic nature and the strong salting-out effect of ILs. On the other hand, due to its considerably hydrophilic nature, gallic acid preferentially migrates toward the IL phase. The achieved results from grape stem extract demonstrated high extraction efficiencies of cholinium dihydrogen phosphate (~99% for resveratrol for the PPG phase and 78% for gallic acid for the IL phase), with considerable selectivity, demonstrating promising outcomes for potential applications.

2024Journal article

Open access

Desenvolvimento e caracterização físico-química, microbiológica e sensorial de muesli de castanha

Publication . Luiz, Adalgilza Boa Morte Nascimento; Ramalhosa, Elsa; Pereira, Ermelinda

O muesli, conhecido por ser um alimento saudável e nutritivo, consiste em uma mistura de cereais, grãos (geralmente aveia em flocos), nozes, sementes e frutas secadas, como uvas passas e tâmaras. O presente trabalho teve como objetivo principal desenvolver um muesli inovador que incorporasse castanha (Castanea sativa Mill.). Para se atingir este objetivo, começou-se por caracterizar três amostras de muesli comerciais para melhor conhecer os componentes geralmente presentes neste produto, bem como as suas proporções. Em seguida, avaliou-se a secagem de castanhas inteiras (1º ensaio) e partidas (2º ensaio), modelando-se o processo, visando definir o método de secagem a utilizar posteriormente para se obter a castanha a incluir no muesli. Após se ter verificado que o método de secagem mais adequado consistiu em desidratar os frutos já partidos durante 40 minutos, prepararam-se diferentes formulações segundo um desenho experimental de misturas, onde foram testadas várias proporções de aveia, castanha e figo, para encontrar a combinação ideal. Os parâmetros avaliados incluíram a cor, atividade da água, teor de humidade e análise sensorial. Após as análises feitas e tratamento dos dados, a proporção indicada pelo otimizador de resposta, considerando que a formulação final deveria ter uma atividade de água entre 0,4 e 0,6, uma intensidade do aroma a castanha entre 4 e 10 e uma intensidade do sabor a castanha entre 3 e 10, foi de 84,5% aveia, 10,0% castanha e 5,5% figo (Formulação A). De seguida, caracterizou-se esta formulação em termos de cor, atividade da água, teores de humidade, cinzas, gordura, proteína, metais (K, Ca, Mg, Fe, Mn, Zn), perfil de ácidos gordos, análise microbiológica e análise sensorial, bem como mais duas, designadamente: B - 84,5% aveia e 15,5% figo e C - 84,5% aveia e 15,5% castanha. Os resultados mostraram que os valores de atividade de água variaram entre 0,61 e 0,65, a proteína entre12,0 e 12,4%, p.f., e a gordura entre 5,8 e 8,1%, p.f., não existindo diferenças significativas entre formulações. Os ácidos gordos maioritários nas três formulações foram o ácido linoleico (C18:2n6c) e o ácido oleico (C18:1n9c). Relativamente à análise sensorial, os três mueslis apresentaram valores médios de aparência geral elevados (entre 7,9 e 8,2) e uma boa apreciação geral (entre 7,3 e 8,1), indicando boa aceitação. Contudo, a Formulação B (só com figo e aveia) foi a preferida por 44% dos provadores, seguindo-se a Formulação A (aveia, figo e castanha) (33%). Em termos microbiológicos, apenas a formulação A apresentou qualidade microbiológica satisfatória, sugerindo que na elaboração de formulações futuras deva existir um maior controlo das matérias-primas, e o cumprimento de boas práticas de higiene e de fabrico. Em conclusão, a presente dissertação demonstrou que a incorporação da castanha no muesli pode resultar em um produto inovador e saudável, mas também promover a valorização da identidade cultural e das tradições alimentares locais, oferecendo uma alternativa nutritiva e saborosa para os consumidores.

2024Master thesis

Open access