Contamination of stored grain  and derivatives by insect pests and fungi

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Efeito da sazonalidade no teor de selénio e outros micronutrientes na cavala da costa portuguesa

Publication . Rego, Andreia; Gueifão, Sandra; Ventura, Marta; Delgado, Inês; Nascimento, Ana Cláudia; Santiago, Susana; Motta, Carla; Coelho, Inês; Castanheira, Isabel

A cavala é uma das espécies de peixe mais abundantes em Portugal, sendo muito rica em diversas vitaminas e micronutrientes. Entre os micronutrientes existentes neste alimento destaca-se o selénio (Se), essencial para o ser humano, mas que se pode tornar tóxico quando ingerido acima da dose diária recomendada. Sendo parte integrante de um conjunto de proteínas com ação antioxidante (as selenoproteínas) um aporte adequado de Se conduz a um melhor desempenho do sistema imunitário, com repercussões positivas no tratamento e/ou prevenção do cancro ou no retardar do desenvolvimento de doenças degenerativas, como o Alzheimer. O organismo humano não sintetiza o selénio sendo a alimentação a fonte que mais contribui para o aporte diário deste elemento. Neste estudo, pretendeu- se estudar o teor de selénio, e de outros micronutrientes, em cavalas da costa portuguesa. Esta análise foi realizada mensalmente, entre março de 2019 e fevereiro de 2020, sendo o Se determinado por espectrometria de massa acoplada a plasma indutivo (ICP-MS), e os restantes micronutrientes (Zn, Fe, Mg, Cu, K, P) por espectrometria de emissão ótica por plasma acoplado indutivamente (ICP-OES). Concluiu-se que a ordem de concentração dos elementos estudados foi estabelecida como K> P> Na> Mg> Fe> Zn. Relativamente à concentração de Se, e por utilização do teste LSD, foram identificadas algumas diferenças significativas ao longo do ano, variando esta entre 451 e 606 μg/ml, excluindo o mês de maio que foi considerado um outlier. Contudo, este resultado poderá dever-se aos hábitos alimentares da cavala e época de desova, pelo que serão necessários mais anos de estudo, de modo, a se verificarem estas conclusões preliminares.

2021-05Journal article

Open access

The interaction between fungi and insects and its contribute to maize flour food safety

Publication . 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.

2021-09Conference object

Restricted access

The Interaction between Tribolium castaneum and Mycotoxigenic Aspergillus flavus in Maize Flour

Publication . Duarte, Sónia; Magro, Ana; Tomás, Joanna; Hilário, Carolina; Alvito, Paula; Ferreira, Ricardo; Carvalho, M.Otilia

Simple Summary: It is important to hold cereals in storage conditions that exclude insect pests such as the red flour beetle and fungi, especially mycotoxin-producing ones (as a few strains of Aspergillus flavus). This work aims to investigate the interaction between these two organisms when thriving in maize flour. It was observed 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. The insects in contact with the fungi were almost all dead at the end of the trials, suggesting a negative effect of the fungi growth on the insects. Both organisms interacted when in contact. This is the first study on this issue, although further investigation would benefit from clarification on the mechanisms leading to the nature of the detected interactions.

2021-08-14Journal article

Open access

Interaction between T. castaneum and mycotoxin-producing fungi present in milled grains

Publication . Duarte, Sónia; Hilário, Carolina; Tomás, Joana; Alvito, Paula; Boavida, Ricardo; Magro, Ana; Carvalho, Maria Otilia

This work aims to study the interaction between two organisms when they grow together in maize flour: Aspergillus flavus Link and Tribolium castaneum Herbst. Two strains of A. flavus were used, one atoxigenic and the other producing aflatoxins. Trials involved a control of only maize flour, maize flour with insects, maize flour with fungi and maize flour with these both organisms (A. flavus and T. castaneum). The development of all these organisms in maize flour was observed. The mycotoxigenic strain of A. flavus produced aflatoxin B1 and B2. However, this production was significantly higher when the fungi was interacting with insects, exceeding the limits allowed by EU in food. AFG1 and AFG2 were not found in any of the treatments. The fungi development seemed to exert a negative effect on the insects survival, as it caused their death, regardless of the putative chemical defenses that this insect has towards other compting organisms, the benzoquinones. It was observed that the adults of red flour beetle promote not only the dispersal and growth of the fungi, as well as seem to stimulate mycotoxin production.

2022-10-03Conference object

Restricted access

SafeGrains - Contamination of stored grain and derivatives by insect pests and fungi