Instituto Politécnico de Viseu

Scientific Repository

Welcome to the Polytechnic Institute of Viseu Institutional Repository

The aim of this Repository is to give greater visibility to the scientific production of the academic community of the Polytechnic Institute of Viseu, by increasing the impact and use through Open Access, ensuring the storage and preservation of all research produced in its organic units and research centres.

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Email repositorio@sc.ipv.pt

Recent Submissions

Chemical Modification of Pachira aquatica Oil for Bio-Based Polyurethane Wood Adhesives

Publication . Silva, Emilly; Esteves, Bruno; Domingos, idalina; Almeida, Margarida Lopes de; Araújo, Bruno; Chaves, Izabella; Fassarella, Michelângelo; et al.

The development of biomass-based adhesives has attracted interest as an alternative to petroleum-derived synthetic and potentially toxic adhesives. Pachira aquatica oil is a renewable raw material that can be incorporated into an MDI-based polyurethane system. In this study, the chemical composition and reactivity of P. aquatica oil were characterized using GC–MS, FTIR, and hydroxyl index measurements. The oil showed a predominance of saturated fatty acids, particularly methyl hexadecanoate (64.80%), derived from palmitic acid, and exhibited a low initial hydroxyl value. To enhance reactivity, the oil was transesterified with glycerol under different conditions, producing polyols with substantially increased hydroxyl values (412–769 mg KOH g−1 ), as confirmed by the intensified O–H and C–O bands in the FTIR spectra. The polyurethane adhesives were formulated from the selected polyols (P3 and P4) and evaluated at different NCO/OH ratios and pressing temperatures, using ABES shear tests. The highest ABES shear strength recorded was approximately 3.6 MPa, obtained for isocyanate indices between 0.8 and 1.0 and temperatures around 115 ◦C. Although this value represents the best performance among the tested conditions, it remains below the industrial benchmarks typically associated with the EN 205 standard (≈10 MPa). It is important to note that the ABES and EN 205 methods are not directly comparable due to differences in testing protocols. Nevertheless, the results indicate that, under the evaluated conditions, the adhesives exhibit limited mechanical performance and require further optimization.

2025-12-10Research article

Open access

Characterization of Lignocellulosic Byproducts from the Portuguese Forest: Valorization and Sustainable Use

Publication . Macena, Morgana; Gonçalves Oliveira Valente da Cruz-Lopes, Luísa Paula; Grosche, Lucas; Santos-Vieira, Isabel; Esteves, Bruno; Pereira, Helena

The increasing emphasis on environmental sustainability has placed biomass as a versatile and renewable resource, while the management and disposal of forest byproducts remain a significant challenge. This study explores the valorization of forest biomass residues derived from Pinus pinaster, Pinus pinea, and the invasive species Acacia dealbata, with a focus on their potential application as bioadsorbents. A comprehensive physicochemical characterization was conducted for different biomass fractions (leaves, needles, and branches of varying diameters). Leaves and needles contained higher amounts of extractives (from 7.7% in acacia leaves to 18.8% in maritime pine needles) and ash (3.4 and 4.2% in acacia leaves and stone pine needles, respectively), whereas branches contained more holocellulose (from 59.6% in P. pinea small branches to 79.2% in P. pinaster large branches). ATR-FTIR and pHpzc analyses indicated compositional and surface charge differences, with higher pHpzc values in A. dealbata relative to Pinus. TG analysis showed that acacia large branches degraded at a lower temperature (320 °C) compared to Pinus species (440–450 °C). Overall, the findings highlight the suitability of these underutilized forest byproducts as bioadsorbents, contributing to the advancement of circular economy practices.

2025-10-14Research article

Open access

Knowledge about consumption of fruits and vegetables: comparison between Portuguese and French consumers

Publication . Florença, Sofia de Guiné e; Gonçalves, João Carlos; Teixeira-Lemos, Edite; Cunha Silva Reis Lima, Maria Joao; Costa, Cristina Amaro da; de Pinho Ferreira Guiné, Raquel

2025Periodical

Open access

Development of a Mediterranean Diet Recipe Index (MedRI)

Publication . Florença, Sofia de Guiné e; Filipa P. Costa; de Pinho Ferreira Guiné, Raquel; Cunha Silva Reis Lima, Maria Joao; Teixeira-Lemos, Edite; Costa, Cristina Amaro da

Background/Objectives: The Mediterranean Diet (MD) is globally recognized for its nutritional, environmental, and cultural value. Although several indices assess adherence to the MD and its food environments, none evaluate the alignment of individual recipes with MD principles. This study aimed to develop and validate the Mediterranean Diet Recipe Index (MedRI), a novel scoring tool designed to quantify the concordance of recipes with MD guidelines. Methods: The MedRI was conceptualized through a comprehensive literature review and expert panel assessment, integrating two main dimensions: consumption context and recipe composition. The index evaluates ingredient selection, preparation methods, and food group inclusion, with criteria adapted to specific recipe categories. Validation was conducted using a structured questionnaire administered to 244 adults living in Portugal. Statistical analyses included descriptive statistics, Spearman correlations, intra-class correlation coefficients (ICCs), Cohen’s kappa, Chi-square tests, Cramer’s V, and principal component analysis (PCA). Results: Validation results demonstrated strong internal consistency and construct validity, confirming the reliability and applicability of the MedRI in assessing recipe alignment with MD principles. Conclusions: The MedRI thus represents a reliable and innovative tool to assess and promote culinary practices consistent with the MD. It holds potential applications in nutrition education, public health policymaking, and gastronomic research, supporting the advancement of sustainable and health-promoting dietary models.

2025-12-11Journal article

Open access

LIFE CYCLE ASSESSMENT OF PIG PRODUCTION: A CASE STUDY

Publication . Ferreira, José; Leite dos Santos, Lenise Maria; Domingos Ferreira, Miguel; OLIVEIRA VERONICA; RODRIGUES CARLA; FERREIRA ANTONIO; Domingos, idalina; IRAJ

Pig farming plays a crucial socioeconomic role in the European Union (EU), with Germany, France, and Spain leading pork production. In Portugal, pig farming is vital for regional development and national economy. To ensure future sustainability, it is essential to identify the pig production activities that have the most significant environmental impacts. This study carried out a Life Cycle Assessment (cradle-to-gate) of pig production using a conventional system in central Portugal to identify the phases with the greatest environmental impact. LCA followed the ISO 14040/14044 standards, covering the production cycle, using 1 kg of live pig weight as a functional unit. The analyzed scenario encompasses everything from the production and growth of piglets to the pig fattening phase, including the formulation of specific feed for each stage of development, transport of inputs, use of diesel to generate electricity in the facilities, and management of pig manure. The results highlight feed production and piglet management as the most important steps. The study highlights the importance of sustainable practices in order to mitigate environmental issues such as human carcinogenic toxicity and the ecotoxicity of freshwater and marine water, emphasizing the need for improved strategies in pig farming.

2025Text

Open access