Browsing by Author "Brites, Carla"
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- Assessment of gamma oryzanol variability, an attractive rice bran bioactive compoundPublication . Lageiro, Manuela; Castanho, Ana; Pereira, Cristiana; Calhelha, Ricardo C.; Ferreira, Isabel C.F.R.; Brites, CarlaGamma-oryzanol is a compound present on rice bran, which has been studied for its bioactive properties, including its cytotoxic activity. The gamma-oryzanol biosynthesis occurs on the lipidic membrane of the plant and can be influenced by edaphoclimatic grown conditions. Two Portuguese rice varieties (Ceres and Macarico) from 6 growing environments were analysed in order to explore the influence of the growing conditions on the gamma-oryzanol content, its constituents, and cytotoxic effect against 4 human tumour cell lines (NCI-H460, HeLa, HepG2, and MCF-7). The overall variability of gamma-oryzanol concentration was from 1.56 g/Kg to 3.19 g/Kg, Ceres reveals higher values than Macarico; those concentrations also varied with the growing environment. The environment was also determinant for the individual concentration of the 3 gamma-oryzanol compounds (cycloartenyl ferulate, 24-methylenecycloartanyl ferulate, and campesteryl ferulate). A cytotoxic effect was observed for all the tested tumour cell lines and also varied with the growing environment.
- Chemical composition and bioactive properties of rice bran from different varietiesPublication . Fernandes, Ângela; Barros, Lillian; Calhelha, Ricardo C.; Heleno, Sandrina A.; Castanho, Ana; Brites, Carla; Ferreira, Isabel C.F.R.Rice (Oryza sativa L.) is an important cerealcrop and a staple food for more than half of the world's populations
- Comparative Analysis of Maize Physico-Chemical Parameters and Mycotoxin Levels in Dual EnvironmentsPublication . Carbas, Bruna; Barros, Sílvia; Freitas, Andreia; Silva, Ana Sanches; Brites, Carla; Carbas, BrunaMaize (Zea mays L.) stands as a vital staple food globally, holding significant nutritional and economic value. However, its susceptibility to mycotoxin contamination under stressful environmental conditions poses a considerable concern. This study aimed to assess the quality and pasting characteristics of maize varieties across two distinct regions and examine the occurrence of mycotoxins influenced by climatic factors. Five maize varieties were cultivated in triplicate in the Goleg & atilde; and Coruche regions. The nutritional composition (protein, fat, fiber, ash, starch, and lutein), pasting properties, and mycotoxin levels were evaluated. A statistical analysis revealed notable differences in the nutritional profiles of the maize varieties between the two regions, particularly in the protein and lutein content. The peak viscosity ranged from 6430 to 8599 cP and from 4548 to 8178 cP in the maize varieties from the Coruche and Goleg & atilde; regions, respectively. Additionally, a significant correlation was observed between the climatic conditions and the grain nutritional quality components (p < 0.05). The M variety showed the highest ash content, protein content, final viscosity, and setback viscosity and the lowest peak viscosity. The Y variety revealed the lowest fat, fiber, and lutein content and the maximum peak viscosity. The incidence of mycotoxins was notably higher in the varieties from Coruche, which was potentially attributable to higher temperatures and lower precipitation levels leading to more frequent drought conditions. Fumonisin B1 was detected in 58% of the varieties from Coruche and 33% of the samples from Goleg & atilde;, while deoxynivalenol was found in 87% and 80% of the varieties from Coruche and Goleg & atilde;, respectively. The H variety, which was harvested in Coruche, exhibited the highest number of fumonisins and higher amounts of protein, lutein, and fat, while fumonisins were not detected in the Goleg & atilde; region, which was potentially influenced by the precipitation levels. The K variety revealed higher protein and lutein contents, a lower amount of fat, excellent pasting properties (a higher peak viscosity and holding strength and a lower peak time), and no fumonisins B1 or B2. This variety may be considered well adapted to higher temperatures and drier conditions, as verified in the Coruche region. In conclusion, our study underscored the profound impact of environmental factors on the quality and occurrence of mycotoxins in maize varieties.
- Exploiting the bioactive properties of γ-oryzanol from bran of different exotic rice varietiesPublication . Castanho, Ana; Lageiro, Manuela; Calhelha, Ricardo C.; Ferreira, Isabel C.F.R.; Soković, Marina; Cunha, Luís M.; Brites, CarlaThe rice industry is one of the most significant food industries since rice is a widely consumed cereal in the world. As a result of this substantial production, the rice industry has a significant amount of side streams, including bran, representing millions of tons of raw materials mainly designated to animal feed. Rice bran is a rich source of γ-oryzanol, a bioactive compound with substantial health benefits. In this perspective, different bran rice samples from distinct germplasm origins (Philippines, Italy and Portugal) were studied for their γ-oryzanol content by HPLC-PDA, cytotoxicity in four human tumour cell lines, hepatotoxicity in a normal cell line and for their antimicrobial effects on different bacterial and fungal strains. The Ballatinao sample presented the strongest activity against all the tumour cell lines, and was also the sample showing the highest amount of γ-oryzanol, suggesting its contribution to the exhibited cytotoxic properties. Regarding the antimicrobial activity, the tested samples were able to inhibit the majority of bacterial and fungal strains, with the Portuguese Ceres sample being the one presenting the highest bacterial inhibition and the Maluit and Dinorado samples, the highest fungal inhibition. Overall, the results show that rice bran extracts may be considered as potential candidates for antimicrobial agents when incorporated into food matrices.
- Phenolic compounds and bioactivity ot husk trom different rice cultivarsPublication . Serrano, Carmo; Oliveira, Maria Conceição; Castanho, Ana; Ferreira, Isabel C.F.R.; Brites, CarlaThere is a growing interest in food industry to valorize by-products from food production waste, and husk represents near 20% of raw material for rice millers. This study aimed to characterize the rice husk phenolic compounds extracted from different varieties ("Maçarico", "Ronaldo", "Ceres"COTARROZ) that may contribute to valorize these by-products. The in vitro antioxidant properties of the phenolic extracts were also investigated. The phenolic composition of extracts under study was identified and fully characterized by HPLC-DAD-ESI -HRMS/MS. The in vitro antioxidant activity of the extracts was assayed by DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging method, and the ferric reducing antioxidant power (FRAP). The LC-DAD-MS profile of the three rice husk extracts presented as main compounds tricin derivatives, including tricin-glycosides and tricinlignans. Ceres husk presented the highest tricin compounds, while Maçarico husk showed lower amount of these compounds. The antioxidant capacity evaluated by DPPH and FRAP assays follow the same trend as the phenolic profiles. The results show that Ceres husk have potential to be valorized in order to provide flavonoids compounds that can increase paddy rice shelf life. Future works will be conducted in order to evaluate also their antibacterial and cytotoxic properties against tumor and non-tumor cells.
- Rapid screening of fumonisins in maize using near-infrared spectroscopy (NIRS) and machine learning algorithmsPublication . Sampaio, Pedro; Barros, Sílvia Cruz; Freitas, Andreia; Silva, Ana Sanches; Brites, Carla; Carbas, BrunaFumonisins occurrence in maize represents a significant global challenge, impacting economic stability and food safety. This study evaluates the potential of near-infrared (NIR) spectroscopy combined with chemometric al- gorithms to detect fumonisins in maize. For fumonisin B1 (FB1) and B2 (FB2) levels were developed predictive NIR models using partial least squares (PLS) and artificial neural networks (ANN). PLS models demonstrated strong correlation coefficient (R2) values of 0.90 (FB1), 0.98 (FB2), and 0.91 (FB1 + FB2) for calibration, with ratio of prediction to deviation (RPD) values ranging 2.8–3.6. Similarly, ANN models showed good predictive performance, particularly for FB1 + FB2, with R = 0.99, and the root means square error (RMSE) of 131 μg/kg for calibration; and R = 0.95, RMSE = 656 μg/kg for validation. These findings underscore the efficacy of NIR spectroscopy as a rapid, non-destructive tool for fumonisin screening in maize, with chemometric algorithms enhancing model accuracy, offering a valuable method for ensuring food safety.
- Spectral markers and machine learning: Revolutionizing Rice evaluation with near infrared spectroscopyPublication . Sampaio, Pedro Sousa; Carbas, Bruna; Soares, Andreia; Sousa, Inês; Brites, CarlaThe evaluation of rice varieties is a complex, time-consuming process requiring advanced equipment. This study aimed to discriminate 22 commercial rice varieties from six types by analyzing biochemical, physicochemical, and cooking properties. Near-infrared (NIR) spectroscopy, combined with machine learning, linked molecular properties with quality traits, offering a high-throughput solution. Partial Least Squares (PLS) models accurately predicted parameters such as whiteness (R2 = 0.94), width (R2 = 0.94), resilience (R2 = 0.96), and springiness (R2 = 0.98), highlighting key wavelength regions. Principal Component Analysis (PCA) revealed distinct clustering patterns, while Partial Least Squares Discriminant Analysis (PLS-DA) achieved a 17 % error rate in external predictions. Spectral markers at A6032/4457 cm-1, A7004/5241 cm- 1, and A7004/4749 cm-1 reflected biomolecular differences among varieties. This innovative approach enables precise quantification, classification, and differentiation of rice types, enhancing quality control, improving consumer satisfaction, and optimizing breeding selection processes efficiently.
- Valorising rice husk as sources of bioactive compoundsPublication . Fernandes, Ângela; Barros, Lillian; Calhelha, Ricardo C.; Heleno, Sandrina A.; Castanho, Ana; Brites, Carla; Ferreira, Isabel C.F.R.Rice husk, a by.product of the rice milling industry, is one of the agricultural waste materialsthat has received high attention.