Departamento de Alimentação e Nutrição
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- 6th International Conference on Food Contaminants: Challenges on Emerging Contaminants and Planetary Health: Book of AbstractsPublication . Vasco, Elsa; Alvito, PaulaThe 6th International Conference on Food Contaminants (ICFC2025), focused on Challenges in Emerging Contaminants and Planetary Health, was held in person from 25–26 September 2025 at the auditorium of the Museu de Eletricidade, Casa da Luz, in Funchal, Madeira, Portugal. The conference addressed the growing challenge posed by emerging contaminants (ECs) in food and the environment, emphasising how their spread through the food chain threatens food safety and public health. Discussions explored policies to reduce exposure to food contaminants, examined the health impacts of chemical and biological contaminants—including occurrence, exposure assessment, and biomonitoring—highlighted advances in analytical methods for detecting emerging contaminants, and considered the full spectrum of their toxicity. These interconnected themes framed a comprehensive dialogue on safeguarding both human health and the wider ecosystem. This multidisciplinary meeting provided a dynamic forum for established experts and early-career researchers to exchange the latest knowledge on food contaminants and their implications for human and planetary health. The scientific programme featured one keynote lecture, five invited lectures, 14 oral presentations, 43 poster presentations, and two round-table discussions. A Best Poster Award was also presented.
- Challenges of the Application of In Vitro Digestion for Nanomaterials Safety AssessmentPublication . Vital, Nádia; Gramacho, Ana Catarina; Silva, Mafalda; Cardoso, Maria; Alvito, Paula; Kranendonk, Michel; Silva, Maria Joao; Louro, HenriquetaConsidering the increase in the production and use of nanomaterials (NM) in food/feed and food contact materials, novel strategies for efficient and sustainable hazard characterization, especially in the early stages of NM development, have been proposed. Some of these strategies encompass the utilization of in vitro simulated digestion prior to cytotoxic and genotoxic assessment. This entails exposing NM to fluids that replicate the three successive phases of digestion: oral, gastric, and intestinal. Subsequently, the resulting digestion products are added to models of intestinal cells to conduct toxicological assays, analyzing multiple endpoints. Nonetheless, exposure of intestinal cells to the digested products may induce cytotoxicity effects, thereby posing a challenge to this strategy. The aim of this work was to describe the challenges encountered with the in vitro digestion INFOGEST 2.0 protocol when using the digestion product in toxicological studies of NM, and the adjustments implemented to enable its use in subsequent in vitro biological assays with intestinal cell models. The adaptation of the digestion fluids, in particular the reduction of the final bile concentration, resulted in a reduced toxic impact of digestion products.
- Ciguatera toxins, a potential health risk emerging in Europe: overview of progress and challengesPublication . Alvito, Paula; Gago-Martínez, Ana; AlvitoCiguatera Poisoning (CP) is considered an emerging risk of concern in several places worldwide. The risk of CP in Europe is currently being investigated, and important advantages have been achieved under two EuroCigua projects, which allowed the characterization of Caribbean Ciguatoxins as the main responsible for the contamination in the European Coastal areas investigated. Important challenges and limitations, particularly the ones related to the lack of reference materials and of relevant samples that enable to associate the contaminated fish consumption with human intoxication, are the most critical aspects hindering the progress from both analytical and toxicological perspectives. This review aims to provide an update on the most recent advances in CP in Europe on the source of the toxins involved in contamination, their toxicology and pharmacology, and their detection and characterization in order to contribute to envisioning the toxic mechanism of CP in humans.
- Genomic Analysis of Antibiotic Resistance and Virulence Profiles in Escherichia coli Linked to Sternal Bursitis in Chickens: A One Health PerspectivePublication . Ribeiro, Jessica; Silva, Vanessa; Freitas, Catarina; Pinto, Pedro; Vieira-Pinto, Madalena; Batista, Rita; Nunes, Alexandra; Gomes, João Paulo; Pereira, José Eduardo; Igrejas, Gilberto; Barros, Lillian; Heleno, Sandrina A.; Reis, Filipa S.; Poeta, PatríciaAbstract: Sternal bursitis is an underexplored lesion in poultry, often overlooked in microbiological diagnostics. In this study, we characterized 36 Escherichia coli isolates recovered from sternal bursitis in broiler chickens, combining phenotypic antimicrobial susceptibility testing, PCRbased screening, and whole genome sequencing (WGS). The genetic analysis revealed a diverse population spanning 15 sequence types, including ST155, ST201, and ST58. Resistance to tetracycline and ciprofloxacin was common, and several isolates carried genes encoding β-lactamases, including blaTEM-1B. Chromosomal mutations associated with quinolone and fosfomycin resistance (e.g., gyrA p.S83L, glpT_E448K) were also identified. WGS revealed a high number of virulence-associated genes per isolate (58–96), notably those linked to adhesion (fim, ecp clusters), secretion systems (T6SS), and iron acquisition (ent, fep, fes), suggesting strong pathogenic potential. Many isolates harbored virulence markers typical of ExPEC/APEC, such as iss, ompT, and traT, even in the absence of multidrug resistance. Our findings suggest that E. coli from sternal bursitis may act as reservoirs of resistance and virulence traits relevant to animal and public health. This highlights the need for including such lesions in genomic surveillance programs and reinforces the importance of integrated One Health approaches.
- Genomic diversity of Enterobacteriaceae on food-processing surfaces: an overlooked non-clinical setting with public health implicationsPublication . Peixoto, Andreia; Nova, Lúcia; Mourão, Joana; Matos, Cátia; Santos, Susana; Rodrigues, João; Saraiva, Margarida; Correia, Cristina Belo; Batista, Rita; Peixe, Luísa; Novais, Carla; Antunes, PatríciaBacterial hazards on contaminated surfaces in food-processing environments pose significant food safety risks. Hygiene monitoring of surfaces in direct or indirect contact with food typically relies on a limited set of bacterial indicators, such as Enterobacteriaceae counts. However, their genomic diversity remains poorly characterised. The aim of this study was to provide a comprehensive genomic characterisation of Enterobacteriaceae recovered from food-contact surfaces after cleaning and disinfection with biocides in foodservice units. Diverse strains were identified, with some STs shared across samples and/or foodservices. - A diverse Enterobacteriaceae population persists on food-contact surfaces even after cleaning and disinfection with biocides, with evidence of cross-contamination. - These surfaces represent critical points of contact for strains that are genetically similar to those circulating in food, environment, and human clinical sources, including strains carrying clinically relevant AMR genes. - Further research is needed to understand the factors driving their persistence and dissemination in foodservice environments, aiming to enhance food safety risk management protocols and protect public health.
- Hygiene challenges in Foodservice Units: Biocide efficacy and bacterial diversity across surfacesPublication . Peixoto, Andreia; Santos, Susana; Rodrigues, João; Saraiva, Margarida; Correia, Cristina Belo; Batista, Rita; Novais, Carla; Antunes, PatríciaContaminated surfaces in food-processing environments represent a significant food safety risk, making the monitoring of hygiene on hands and food-contact surfaces a priority. This study aimed to assess the occurrence and diversity of hygiene indicator bacteria in Portuguese foodservice facilities and to evaluate their association with biocide use. A total of 1,128 hand and surface samples were collected from 107 facilities, with bacterial identification performed by MALDI-TOF-MS and information gathered on the type and concentration of biocides used. More than half of the samples showed unsatisfactory hygiene results, mainly due to high total viable counts and Enterobacteriaceae levels. Forty bacterial species were identified, with Enterobacter cloacae, Klebsiella pneumoniae and Klebsiella oxytoca being the most prevalent. Hygiene performance varied according to the type of biocide applied, with quaternary ammonium compound-based products showing greater effectiveness. Despite appropriate biocide concentrations, the persistence and diversity of bacteria highlight the need to further investigate microbial susceptibility and persistence in order to improve hygiene practices.
- Intestinal Permeability Studies using a more realistic barrier: performance of co-cultures of Caco-2/HT29-MTX cellsPublication . Figueira, Carolina; Gravato, Carlos; Alvito, PaulaThe intestinal barrier, essential for overall health, can have its permeability affected by certain food compounds and additives. Among various models, in vitro cellular monolayers are the most commonly used to study this process. Among these, Caco-2 cells—representing enterocytes—are commonly used, though they lack complexity to mimic some properties of the intestinal barrier. This limitation can be overwhelmed by co-culturing it with HT29-MTX cells, which allows the secretion of mucus and mimics goblet cell functioning. This study aimed to evaluate the intestinal permeability by assessing the paracellular and transcellular transport of lucifer yellow (LY) and propranolol (PR), two intestinal permeability markers, respectively, using a 9:1 co-culture of Caco-2/HT29-MTX cells. Cells were cultivated separately in complete medium. Functional monolayer formation was monitored over 28 days using transepithelial electrical resistance (TEER) measurements in triplicate plates, with values ranging from 450.6 to 1287.3 Ω·cm². Transport assays were conducted on day 21 by applying LY and PR to the apical compartment and measuring their passage to the basolateral side. Apparent permeability coefficients (Papp) and basal recovery values were estimated by fluorescence quantification. Statistical analyses were conducted to evaluate variability in TEER, Papp, and basal recovery results. The Shapiro-Wilk test was used to assess normality, and comparisons used one-way ANOVA followed by Tukey’s test or the Kruskal-Wallis test followed by Dunn’s test when requisites of ANOVA were not met. Significant differences in TEER values were observed between days 8–20 (p = 5.8e-11), 22–28 (p = 2.3e-09), and before vs. after transport on day 21 (p < 2.2e-16). For day 21 transport assays, a significant difference was found in LY basal recovery for two out of three plates (p = 0.03). As for the PR Papp values, there is a significant difference between duplicate plates (p = 0.005), as one plate was excluded due to a poor calibration curve fit. These findings will inform improvements to the protocol for assessing intestinal permeability using co-culture models. Thus, Caco-2/HT29-MTX co-culture appears to be a promising model for evaluating the impact of food components and additives on the intestinal barrier.
- Surface hygiene in food environments: challenges with biocide efficacy and bioindicatorsPublication . Peixoto, Andreia; Matos, Cátia; Santos, Susana; Rodrigues, João; Saraiva, Margarida; Belo Correia, Cristina; Batista, Rita; Peixe, Luísa; Novais, Carla; Antunes, PatríciaThe presence of bacterial hazards on contaminated surfaces in food-processing environments poses significant food safety risks. Monitoring and hygiene verification of surfaces in direct or indirect contact with food remains a top priority for food business operators. Sanitation uses antimicrobial compounds, biocides (disinfectants/antiseptics), whose effectiveness on surface microbiota depends on microorganisms’ susceptibility and factors such as concentration and contact time. The aim of this stydy was to assess the post-disinfection occurrence and diversity of hygiene indicator bacteria on kitchen surfaces of Portuguese foodservice facilities and correlate their presence with biocide usage. Despite recommended biocide use, poor hygiene of surfaces in direct or indirect contact with food was observed. The presence of diverse, potentially pathogenic and recurrent bacterial species suggests persistence, reintroduction, and/or cross-contamination. Identifying phenotypic and genetic markers of persistence, including biocide susceptibility, is crucial for developing real-time hygiene bioindicators and ensuring food safety.
- Towards safer edible insects: assessing contaminant bioaccumulation and depuration capacity in Tenebrio molitorPublication . Cardoso, Diogo N.; Alvito, Paula; de Boevre, Marthe; Silva, Ana Rita; Pinto, José; Rodrigues, Ana; Prodana, Marija; Silva, Patricia; Mostafaie, Amid; Loureiro, SusanaThe integration of insects into sustainable food and feed chains demands a robust evaluation of their capacity to accumulate and eliminate contaminants. Understanding these dynamics is fundamental to ensuring consumer safety and supporting the development of regulatory standards for insect-derived products. This study assessed the bioaccumulation and depuration kinetics of metal(loid)s (As, Cd, Pb) and mycotoxins (Aflatoxin B1, Ochratoxin A, Deoxynivalenol, and Zearalenone) in the yellow mealworm Tenebrio molitor, a species already authorized for human consumption in the EU. Larvae were reared on feed substrates artificially spiked at the maximum levels allowed for animal feed under EU legislation. The experimental design included 21 days of exposure followed by a 21-day elimination phase on uncontaminated substrate, to evaluate both uptake and depuration efficiency under realistic production conditions. Distinct toxicokinetic patterns were observed among metals. Arsenic displayed the highest accumulation potential, reaching internal concentrations of approximately 7 mg/kg dry weight (DW) at the end of exposure, with a progressive but incomplete decline during depuration. Cadmium accumulated steadily to ~2.5 mg/kg DW, exceeding the current feed limit, but was rapidly eliminated below regulatory thresholds within one day of clean feeding. Lead, in contrast, showed low assimilation and rapid clearance, remaining consistently below EU maximum levels. Mycotoxins and their metabolites were not detected above quantification limits in any treatment, confirming the species’ limited bioaccumulation potential for these compounds. Overall, the results highlight Tenebrio molitor’s high depuration capacity and resilience to transient contaminant exposure. These findings highlight the need to apply toxicokinetic principles in insect risk assessment to define effective depuration periods and ensure safe, circular production systems.