Biblioteca Digital do IPB

Publications Repository of the Polytechnic Institute of Bragança

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The Digital Library of IPB (Biblioteca Digital do IPB), promotes and provides open access to scientific literature produced by the IPB academic community, promoting integration, visibility and sharing of scientific information granting the preservation of intellectual memory of the Instituto Politécnico de Bragança.

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Recent Submissions

Optimization of heat and ultrasound-assisted extraction of Eucalyptus globulus leaves reveals strong antioxidant and antimicrobial properties

Publication . Lima, Laíres; Pereira, Ana I.; Vaz, Clara Bento; Amorim Sá Ferreira, Maria Olga; Dias, Maria Inês; Heleno, Sandrina A.; Calhelha, Ricardo C.; Barros, Lillian; Carocho, Márcio

The extraction of phenolic compounds from eucalyptus leaves was optimized using heat and ultrasound-assisted techniques, and the bioactive potential of the resulting extract was assessed. The independent variables, including time (t), solvent concentration (S), and temperature (T) or power (P), were incorporated into a fivelevel central composite design combined with Response Surface Methodology. Phenolic content was determined by HPLC-DAD-ESI/MS and used as response criteria. The developed models were successfully fitted to the experimental data to identify the optimal extraction conditions. Heat-assisted extraction proved to be the most efficient method for phenolic recovery, yielding 27 ± 2 mg/g extract under optimal conditions (120 min, 76.5 ◦C, and 25 % ethanol, v/v). The extracts exhibited a high concentration of phenolic glycoside derivatives, including gallotannin, quercetin, and isorhamnetin. These findings suggest that the extracts hold promise as natural additives in food technology, owing to their moderate antimicrobial activity and strong antioxidant properties.

2025Journal article

Unknown

Optimization, Learning Algorithms and Applications (OL2A 2024) Part II

Publication . Pereira, Ana I.; Fernandes, Florbela P.; Coelho, João Paulo; Paulo Teixeira, Joao; Lima, José; Pacheco, Maria F.; Lopes, Rui Pedro; Álvarez, Santiago T.; Santiago T.

This volume, CCIS 2280, contains the refereed proceedings of the 4th International Conference on Optimization, Learning Algorithms and Applications (OL2A 2024), a hybrid event held on July 24–26. OL2A provided a space for the research community on optimization and learning to get together and share the latest developments, trends and techniques as well as develop new paths and collaborations. OL2A had the participation of more than three hundred participants in an online and face-to-face environment throughout three days, discussing topics associated with areas such as optimization and learning and state-of-the- art applications related to multi-objective optimization, optimization for machine learning, robotics, health informatics, data analysis, optimization and learning under uncertainty, and the 4th industrial revolution. Three special sessions were organized on the topics Learning Algorithms in Engineering Education, Optimization in the SDG context, and Optimization in Control Systems Design. The event accepted 41 papers. All papers were carefully reviewed and selected from 105 submissions. All the reviews were carefully carried out by a scientific committee of 115 researchers from twenty-six countries.

2024Book

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Optimization, Learning Algorithms and Applications (OL2A 2024) Part I

Publication . Pereira, Ana I.; Fernandes, Florbela P.; Coelho, João Paulo; Paulo Teixeira, Joao; Lima, José; Pacheco, Maria F.; Lopes, Rui Pedro; Álvarez, Santiago T.; Álvarez

This volume, CCIS 2280, contains the refereed proceedings of the 4th International Conference on Optimization, Learning Algorithms and Applications (OL2A 2024), a hybrid event held on July 24–26. OL2A provided a space for the research community on optimization and learning to get together and share the latest developments, trends and techniques as well as develop new paths and collaborations. OL2A had the participation of more than three hundred participants in an online and face-to-face environment throughout three days, discussing topics associated with areas such as optimization and learning and state-ofthe- art applications related to multi-objective optimization, optimization for machine learning, robotics, health informatics, data analysis, optimization and learning under uncertainty, and the 4th industrial revolution. Three special sessions were organized on the topics Learning Algorithms in Engineering Education, Optimization in the SDG context, and Optimization in Control Systems Design. The event accepted 41 papers. All papers were carefully reviewed and selected from 105 submissions. All the reviews were carefully carried out by a scientific committee of 115 researchers from twenty-six countries.

2024Book

Unknown

Exploring acorn shells: Phenolic composition and bioactive potential for sustainable valorization

Publication . Mateus, Cristiano; Alonso-Esteban, José Ignacio; Finimundy, Tiane Cristine; Mandim Pires, Ana Filipa; de Oliveira, Izamara; Babo, Pedro; Canadas, Raphael; Ferreira, Isabel C.F.R.; Barros, Lillian

Pedunculate (Quercus robur L.), holm (Quercus rotundifolia Lam.), and cork (Quercus suber L.) oaks are abundant across the Portuguese landscape. This study aims to evaluate the phenolic composition and bioactivities of acorn shell samples and determine their potential as a functional compound source. In total, five acorn shell samples collected in different locations and from different species were analyzed: Q. rotundifolia (Q. rot-1 and Q. rot-2), Q. suber (Q. sub-1 and Q. sub-2) and Q. robur (Q. rob-1). A total of nine phenolic compounds were tentatively identified, namely gallic and ellagic acids and derivatives. Digalloyl hexoside was the compound detected in higher concentrations in all extracts (2.093 – 8.3 mg/g extract). Q. suber samples exhibited the lowest IC50 values for TBARS assay, lower than the positive control used (Trolox). Overall, the studied samples demonstrated the capacity to inhibit the proliferation of all tumor cell lines tested. Sample Q. sub-1 demonstrated the most promising antibacterial capacity. According to the results, the acorn shell extracts exhibited promising potential, and it may be interesting to conduct a deeper study on the samples of this species.

2025Journal article

Unknown

Machine learning classification of consumption habits of creatine supplements in GYM goers

Publication . Magalhães, Patrícia C.; Encarnação, Samuel; Schneider, Andre; Miguel Forte, Pedro; de Araújo Teixeria, José Eduardo; Monteiro, A. M.; Barbosa, Tiago M.; Pereira, Ana M.; ENCARNACAO, SAMUEL GONCALVES ALMEIDA

The aim is to identify usage patterns and the main factors that influence creatine supplementation, providing a basis for future educational interventions and recommendations for safe and effective use. The study was applied to gym goers in Bragança, where a QR code for a survey was released. 158 people participated, 65 non-consumers of creatine supplementation (37.34% men; 22.78% women) and 95 consumers (15.19% men; 24.68% women). Five machine learning algorithms were implemented to classify creatine consumption in gym goers: Logistic Regression, Gradient Boosting Classifier, Ada Boost Classifier, Xgboost Classifier. K-folds cross-validation was implemented to validate the machine learning performance. There was an increased proportion of females with considered themselves not sufficiently informed about the creatine effects/side effects (22.2%) in comparison to males (8.47%), p=0.03. The AdaBoost classifier exposed the best overall performance (86%) in classifying overuse of creatine in gym goers based on their Smoke habits (r = 0.33), grams of creatine used per day (r = 0.50) and lack information about the side effects of creatine intake (r = -0.33). The K-folds method validates the results with very good performance (86%). In conclusion, the five machine learning methods employed well characterized the overuse of creatine in gym goers based on smoke habits, grams of creatine per day, and lack information about the side effects of creatine intake.

2025Journal article

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