Percorrer por autor "Rocha, Pedrina"
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- Can the region of production affect the quality and composition of olive oil? Comparative study on two olive cultivarsPublication . Rocha, Pedrina; Lamas, Sandra; Casal, Susana; Martins, Luísa L.; Rodrigues, NunoPortugal is a notable olive oil-producing country, gaining prominence in the last decade. This study examined how geographic origin influences olive oil quality by analyzing samples from three key regions (Alentejo, Beira Interior, and Trás-os-Montes) and two major cultivars: Cobrançosa and Galega. All oils met the extra-virgin classification criteria, with free acidity consistently below 0.30%, and peroxide values ranging from 2.3 to 6.7 mEq O₂/kg. Alentejo oils were sensorially more intense, showing higher bitterness and pungency (up to 6.1 and 6.8, respectively). Significant chemical differences were also observed: Trás-os-Montes oils presented the highest monounsaturated fatty acid content (up to 76% MUFA), whereas Alentejo showed the greatest concentrations of hydroxytyrosol-based compounds (up to 450 mg/kg) and strong antioxidant activity (DPPH inhibition up to 80%). Beira Interior oils exhibited the highest α-tocopherol levels (up to 428 mg/kg). Heatmaps and principal component analysis (PCA) revealed clear chemical differences based on origin, demonstrating that environmental factors significantly influence composition, oxidative stability, and antioxidant potential. These results highlight the role of terroir in shaping both the sensory and chemical properties of Portuguese olive oils.
- Controlo de qualidade alimentar de estabelecimentos da ilha de São Vicente durante a pandemia Covid-19Publication . Rocha, Pedrina; Rodrigues, Nuno; Ferro-Lebres, VeraOs serviços de alimentação em São Vicente estão em constante crescimento, assim, a segurança sanitária alimentar deve ser uma prioridade para estes estabelecimentos, especialmente durante a pandemia de Covid-19. O presente estudo teve como objetivo avaliar os resultados das inspeções higio-sanitárias realizadas na ilha de São Vicente em Cabo Verde. Os obtidos mostraram que os estabelecimentos alimentares da ilha de São Vicente não estavam familiarizados com as Normas Sanitárias de Prevenção e Transmissão SARS-COV 2. Estas ações de fiscalização podem ter tido um papel importante na sensibilização para melhorar prática de segurança alimentar de forma a minimizar o surto de Covid-19 na ilha.
- Influence of geographical origin on the sensory and volatile profiles of Portuguese monovarietal olive oilsPublication . Rocha, Pedrina; Ruano, Daniela; Ferreiro, Nuno; Martins, Luísa L.; Rodrigues, NunoThe sensory and volatile profiles of monovarietal olive oils from the Portuguese cultivars Cobrançosa and Galega, produced in three geographical regions (Alentejo, Beira Interior, and Trás-os-Montes), were investigated to evaluate the effects of cultivar and geographical origin. All samples were classified as extra virgin olive oil. Sensory analysis revealed significant differences (p < 0.05) between cultivars and among regions. Cobrançosa olive oils exhibited an intense green sensory profile, characterized by high green fruitiness, and tomato, apple, and herbaceous notes, particularly in oils from Trás-os-Montes and Alentejo. In contrast, Galega olive oils showed a more balanced and moderated sensory profile, with lower intensities of bitterness and pungency and variability among regions. Volatile characterization by HS–SPME–GC–MS led to the identification of 26 compounds in Cobrançosa and 29 in Galega olive oils, grouped into seven chemical families. Olive oils from Beira Interior and Trás-os-Montes showed higher concentrations of lipoxygenase-derived C5 and C6 compounds, such as (E)-2-hexenal, associated with green and fruity sensory sensations, whereas Alentejo oils exhibited lower volatile diversity but higher relative abundance of certain sesquiterpenes. Pearson correlation analysis revealed a strong association between sensory descriptors and key volatile compounds, highlighting region specific sensory-chemical patterns. Linear discriminant analysis (LDA) based on sensory and volatile data achieved excellent classification performance, with accuracies up to 100% for both cultivars. Overall, the results demonstrate an interaction between cultivar and geographical origin, supporting the use of sensory and volatile profiling as tools for the differentiation and authentication of Portuguese monovarietal olive oils.