Percorrer por autor "Martins, Davide Coelho"
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- Determination of global heat transfer coefficient in olive paste malaxation and its impact on olive oil quality outcomePublication . Martins, Davide Coelho; Souza, Thiago Pereira Pio de; Peres, António M.; Rodrigues, NunoEffective control of malaxation conditions is crucial for extra virgin olive oil (EVOO) quality. This study evaluated the combined effects of malaxation temperature (25, 32, 40ºC), duration (30, 45, 60 min), and olive paste mass (350 g, 700 g) on EVOOs’ physicochemical and sensory parameters. Global heat transfer coefficients (U) were calculated under steady-state conditions ranging from 2 to 63 Wm−2ºC−1 and correlated with the oil’s quality parameters. Principal component analysis confirmed that processing variables studied strongly influenced EVOO profiles. Higher U values improved sensory attributes at shorter malaxing durations but detrimental under prolonged heating. Antioxidant activity increased either with lower paste mass and 45 min of malaxation, or with higher paste mass and 30 min of malaxation, at temperatures of 25–32°C. Results highlight the complex interaction of processing conditions and suggest that U may be a useful integrating metric of malaxing conditions and, to some extent, EVOO profiles.
- Determination of global heat transfer coefficient in olive paste malaxation and its impact on olive oil quality outcomePublication . Martins, Davide Coelho; Thiago Pereira Pio de; Peres, António M.; Rodrigues, NunoEffective control of malaxation conditions is crucial for extra virgin olive oil (EVOO) quality. This study evaluated the combined effects of malaxation temperature (25, 32, 40ºC), duration (30, 45, 60 min), and olive paste mass (350 g, 700 g) on EVOOs’ physicochemical and sensory parameters. Global heat transfer coefficients (U) were calculated under steady-state conditions ranging from 2 to 63 Wm−2ºC−1 and correlated with the oil’s quality parameters. Principal component analysis confirmed that processing variables studied strongly influenced EVOO profiles. Higher U values improved sensory attributes at shorter malaxing durations but detrimental under prolonged heating. Antioxidant activity increased either with lower paste mass and 45 min of malaxation, or with higher paste mass and 30 min of malaxation, at temperatures of 25–32°C. Results highlight the complex interaction of processing conditions and suggest that U may be a useful integrating metric of malaxing conditions and, to some extent, EVOO profiles.
- Differential regulation of antioxidant machinery on grass pea partial resistance against powdery mildew and rust pathogensPublication . Martins, Davide Coelho; Mendes, Francisco A.; Araújo, Susana de Sousa; Rubiales, Diego; Patto, Maria Carlota VazPowdery mildew (Erysiphe pisi, E. trifolii) and rust (Uromyces pisi) are important diseases affecting grass pea (Lathyrus sativus). This study investigates grass pea’s histological, enzymatic, and metabolic responses to these pathogens using accessions with contrasting resistance. Partially resistant (PR) accessions exhibited smaller fungal colonies from 48 h after inoculation (HAI) onwards. Enhanced superoxide dismutase (SOD) activity was observed as early as 12 HAI in PR accessions against both powdery mildews, associated with increased ascorbate peroxidase (APX) and catalase (CAT) activity in E. trifolii and E. pisi infections, respectively. Moreover, phenolic compounds and flavonoids accumulated in E. trifolii-infected PR accessions (6–48 HAI). For rust, APX activity rose at 48 HAI in PR accessions. These findings suggest that partial resistance (PR) in grass pea is characterized by restricted pathogen invasion and a dynamic regulation of reactive oxygen species (ROS) scavenging enzymes, with responses varying across pathosystems. This highlights the importance of pathogen-specific selection strategies to minimize the risk of resistance breakdown and promote durable disease resistance in breeding programs.