Browsing by Author "Carvalho, M.O."
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- Assessment of multiple mycotoxins in maize flour samples from Portugal under SafeGrains projectPublication . Duarte, S.; Magro, A.; Oliveira, C.; Rosim, R.; Alvito, Paula; Carvalho, M.O.One of the most relevant problems in stored grains is the contamination by insects and mycotoxin-producing fungi. Tribolium castaneum is one of the most common insect pests of stored products. Its presence makes cereals more susceptible to the spread of the fungi Aspergillus flavus, which may produce mycotoxins. The aim of this work was to evaluate the mycotoxin profile of maize flour infested by T. castaneum adults, alone or in combination with mycotoxigenic A. flavus strain (MUM-UMinho). Maize collected directly from fields was stored at 4 ºC and then ground and sieved to obtain maize fl our. Multiple mycotoxin profile of maize flour was determined in three different assays: i) controls (n=8), ii) inoculated with T. castaneum adults (insect assay, n = 24), iii) inoculated with A. flavus conidia (fungus assay, n = 8) and iv) inoculated with both organisms (mixed assay, n = 24). Samples were analyzed by liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) according to Franco et al. (2019) for determination of aflatoxins (AFs) B1, B2, G1 and G2, deoxynivalenol (DON), zearalenone(ZEN) and fumonisins (FBs) B1 and B2. The limits of detection (LOD) and quantification (LOQ) of the analytical method were 6.1 and 18.0 μg/ kg for DON, respectively. For AFs, ZEN and FBs, LOD and LOQ varied between 0.2 – 0.9 and 0.6 – 2.5 μg/kg, respectively. DON, ZEA, FB1 and FB2 were detected in control assays at mean levels ranging from 33-50, 2-6, 112-144 and 49-75 μg/kg, respectively. AFs were not detected in controls. Insect, fungi and mixed assays presented the same mycotoxin profile (with contents in the same order of magnitude), except for AFB1, which was detected only in mixed assays. Although the levels of mycotoxins are below the legislated ones (Commission Regulation (EU) 2023/915), they point out to the presence of multiple mycotoxins in raw maize flour and to a potential impact between insects and mycotoxigenic strains in which concerns AFB1. Data presented here agree with previous assays from this team describing significantly higher concentration in the maize flour inoculated with both organisms (Duarte et al, 2021).
- SafeGrains - Contamination of stored grain and derivatives by insect pests and fungiPublication . Carvalho, M.O.; Mourato, M.; Louro, L.; Sousa, I.; Raymundo, A.; Alvito, P.; Magro, A.; Barros, G.; Ferreira, R.; Duarte, S.About contamination of stored grain and derivatives by insect pests and fungi.
- The interaction between fungi and insects and its contribute to maize flour food safetyPublication . Alvito, Paula; Duarte, Sónia; Magro, Ana; Tomás, Joanna; Hilário, Carolina; Ferreira, Ricardo; Carvalho, M.O.Globally, 140 million children under five years are stunted, and wasting still impacts the lives of over 47 million children, especially during the complementary feeding period. Improved formulations of complementary foods (CFs) with animal-source foods (ASFs) is an important strategy to improve infant and young child feeding. However, ASFs are expensive in many food-insecure settings where edible insects abound. Some insects as Tenebrionidae species are edibles and could, in future, be used as CFs. It is therefore important to characterize the effects of other organisms present in flours that could interact with insects, such as mycotoxigenic fungi, that produce mycotoxins. Insects may trigger fungi growth and mycotoxin production therefore it will be important to evaluate the possible influence of insects in maize flour on the production of mycotoxins (aflatoxins) as a contribution to a better understanding of this complex interaction and to the safety of future alternative CFs. Maize was collected directly from fields was stored at −4 ◦C and then ground and sieved to obtain maize flour. The maize flour was incubated under appropriate conditions of 30 ◦C ± 2 ◦C and 70% ± 5% RH for eight weeks on its own (control), inoculated with A. flavus conidia (fungus assay), inoculated with T. castaneum adults (insect assay) or inoculated with both organisms (mixed assay). Aflatoxins analysis were performed in all samples by liquid chromatography with fluorescence detection (HPLC-FD). Results showed that, when both organisms were together, the mycotoxins detected in maize flour were far higher than when the fungi were on their own, suggesting that the presence of insects may contribute positively to fungi development and mycotoxin production. This is the first study on this issue. Further investigation would benefit from clarification on the mechanisms leading to the nature of the detected interactions and to contribute to the safety of alternative foods, specially those that could be used, in future, for children consumption.