Sílvia Cruz Barros

Background: Rice is susceptible to contamination by mycotoxins and ergot alkaloids, posing significant risks to food safety. Despite growing evidence of their co-occurrence, few methods allow simultaneous determination of regulated, emerging mycotoxins and ergot alkaloids in rice. Objective: A screening method based on the of Quick, Easy, Cheap, Effective, Rugged and Safe (QuEChERS) method coupled with ultra-high performance liquid chromatography combined with time-of-flight mass spectrometry (UHPLC–TOF-MS) was develop and validated for the simultaneous determination of 11 mycotoxins and 12 ergot alkaloids in rice. Methods: Chromatographic parameters, including column selection, gradient program, flow rate, and injection volume, were optimized to ensure adequate separation and sensitivity. Two extraction approaches, solid–liquid extraction (SLE) and QuEChERS, were systematically compared, and key parameters such as extraction solvent, extraction time, and salt composition were optimized to maximize recoveries across chemically diverse analytes. The validated method was applied to 41 commercially available rice samples from the Portuguese market. Results: The validated method showed recoveries between 71% and 119%, repeatability (RSDr ≤20%), inter-day precision (RSDR ≤25%), and LOQs compliant with European Union (EU) performance criteria. Aflatoxin G2 and sterigmatocystin were the most frequently detected mycotoxins, with three samples exceeding the legal limit for total aflatoxins (4 µg/kg). Mycophenolic acid was also detected in two samples. Conclusion: The developed method demonstrated adequate sensitivity, selectivity, and precision for multi-mycotoxin surveillance, highlighting the relevance of monitoring emerging mycotoxins in rice. Highlights: QuEChERS combined with UHPLC–TOF-MS enables simultaneous screening of 23 analytes, including ergot alkaloids and regulated and emerging myxotoxins. The method was validated according to Regulation (EU) 2023/2782. Aflatoxin G2 and sterigmatocystin were detected in Portuguese market rice. Mycophenolic acid was detected as an emerging contaminant.

Fumonisins and deoxynivalenol (DON) are toxic secondary metabolites, produced by Fusarium species frequently contaminating maize, representing a critical challenge to food safety and human health. Conventional analytical methods, such as HPLC and ELISA, are accurate but time-consuming and require complex sample preparation. In contrast, near-infrared spectroscopy (NIR) has emerged as a rapid, non-destructive, and cost-effective alternative for mycotoxin screening. This study investigates the potential of NIR spectroscopy combined with chemometric techniques to detect and quantify fumonisins (primarily FB1 and FB2) and DON in maize. A total of 60 maize samples were analyzed with mean concentrations of 534 µg/kg for FB1, 208 µg/kg for FB2, and 130 µg/kg for DON. The highest cumulative contamination of FB1 + FB2 reached 3420 µg/kg. While 30% of the samples showed no detectable fumonisin contamination, DON was absent in 17% of the samples. The best performing predictive models were developed using second-derivative pre-processing of the NIR spectra. The NIR calibration model yielded coefficients of determination (R²) of 0.91 for FB1, 0.88 for FB2, and 0.92 for DON, with corresponding root mean square errors (RMSE) of 683, 282, and 115 µg/kg, respectively. These results demonstrate that NIR spectroscopy, particularly when integrated with multivariate analysis, is a promising tool for distinguishing contaminated from uncontaminated maize and estimating mycotoxin levels with reasonable accuracy. These findings support the application of NIR as a practical tool for routine screening and quality control in the maize supply chain.

This review provides a comprehensive overview of strategies to mitigate pesticide residues in food, examining both household and industrial processing techniques alongside the emerging role of Artificial Intelligence (AI). Simple household methods, such as washing, peeling, and thermal processing (e.g., boiling, frying), are effective. For instance, washing with running water achieves a reduction of up to 77% in residue for some vegetables. Additionally, processes like jam-making or frying can significantly reduce specific residues. Industrially, advanced methods such as ozonated water washing, ultrasonification, and cold plasma are employed for high efficiency while preserving food quality. Critically, AI is emerging as a powerful, indirect tool through predictive modelling, AI-assisted sorting/screening, and consumer guidance, enhancing precision agriculture and regulatory analytics. The review paper concludes that a combination of these diverse methods is essential for minimizing pesticide exposure and ensuring a safer food supply.

Phenolic compounds in apples provide significant health benefits, including antioxidant, and anti-inflammatory properties. The phenolic profile and content in apples are influenced by genetics, environmental factors, and agricultural practices. Photoselective nets, which are designed to filter specific wavelengths of light, might impact fruit quality and phenolic content. This study aimed to assess the effects of photoselective nets on the antioxidant capacity and phenolic composition of three different apple cultivars grown under the same edaphoclimatic conditions. Five nets were selected. Fruits grown under the nets were compared with unprotected fruits. Antioxidant capacity was evaluated, and phenolic profiles were established by Ultra-High Performance Liquid Chromatography coupled with Time of Flight–Mass Spectrometry (UHPLC-ToF-MS). The results demonstrate a significant impact of the nets on the phenolic composition and antioxidant activities of apples. Different net colors had distinct effects on the accumulation of phenolic compounds, with some nets increasing flavonoid production and others reducing the levels of important phenolic acids. The gray and IRIDIUM^® Red nets enhanced the production of quercetin and its derivatives, while chlorogenic acid showed a general decline under net-covered conditions, indicating a possible dependence on direct sunlight. The responses were also cultivar-dependent, with Gala redlum apples showing the largest reductions in phenolic compounds when protected by nets. Antioxidant assays also confirmed that the nets influenced the antioxidant potential of apples in a cultivar-dependent manner. These findings suggest that the retention of bioactive compounds in fruits might be strategically managed by selecting appropriate net materials for specific cultivars.

Citrus medica L. is a traditional citrus fruit that is rich in bioactive compounds and has the potential to be used as a natural source of food additives. This study aims to evaluate the antioxidant capacity and characterize the phenolic compounds present in the peels (including flavedo and albedo), pulp, and seeds of citron. The results showed that, compared to the other parts, the pulp had a substantially higher Antioxidant Activity Coefficient (AAC) of 168.2. The albedo and the seeds had significantly lower AAC values, while the green and yellow flavedo showed noteworthy results. O-coumaric acid was the predominant phenolic acid in all of the citron fractions; it was found in the highest concentration in albedo (37.54 µg/g FW). Flavanones and flavanols were the primary flavonoids in the pulp, peel, and seeds, with total flavonoid concentration ranging from ~9 µg/g FW in seeds to 508 µg/g FW in the pulp. This research offers significant insights into the antioxidant properties of this ancient fruit, emphasizing its potential applications as a natural source of antioxidants to be used in different applications.

Maize (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 Golegã 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 Golegã 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 Golegã, while deoxynivalenol was found in 87% and 80% of the varieties from Coruche and Golegã, 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 Golegã 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.

Consumers are increasingly seeking natural alternatives to chemical compounds, including the use of dried aromatic plants as seasonings instead of salt. However, the presence of pyrrolizidine alkaloids (PAs) in food supplements and dried plants has become a concern because of their link to liver diseases and their classification as carcinogenic by the International Agency for Research on Cancer (IARC). Despite European Union (EU) Regulation (EU) 2023/915, non-compliance issues persist, as indicated by alerts on the Rapid Alert System for Food and Feed (RASFF) portal. Analyzing PAs poses a challenge because of their diverse chemical structures and low concentrations in these products, necessitating highly sensitive analytical methods. Despite these challenges, ongoing advancements in analytical techniques coupled with effective sampling and extraction strategies offer the potential to enhance safety measures. These developments aim to minimize consumer exposure to PAs and safeguard their health while addressing the growing demand for natural alternatives in the marketplace.

Ergot alkaloids are secondary metabolites resulting from fungi of the genus Claviceps that have proven to be highly toxic. These mycotoxins commonly infect cereal crops such as wheat, rye, barley, and oats. Due to the increase worldwide consumption of cereal and cereal-based products, the presence of ergot alkaloids in food presents a concern for human safety. For this reason, it is essential to develop several analytical methods that allow the detection of these toxic compounds. This review compiles and discusses the most relevant studies and methods used in the detection and quantification of ergot alkaloids. Moreover, the decontamination techniques are also addressed, with special attention to sorting, cleaning, frying, baking, peeling, and ammonization methods, as they are the only ones already applied to ergot alkaloids.