Percorrer por autor "Sampaio, A."
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- Contamination by aflatoxins in different food matrices produced and consumed in Mozambique.Publication . Matusse, Cláudio ; Macuamule, Custódia; Bila, João; Sampaio, A.; Venâncio, Armando; Rodrigues, Pedro JoãoMycotoxins are toxic metabolites produced by various moulds that frequently contaminate food worldwide, being significant contributors to food losses in developing countries. In Mozambique, there is no comprehensive knowledge of the risk of mycotoxins in the country, nor structured actions to reduce the impacts of mycotoxins and promote health and food security in disadvantaged populations. This research aimed to analyse the level of contamination by aflatoxins in different food matrices produced and consumed in southern Mozambique. Ten samples were collected from each matrix (maize, rice, and peanut) in each of the 3 districts (Chongoene, Manjacaze and Chókwe) of Gaza province, and 10 peanut samples in each of the 3 districts (Massinga, Inhambane and Inharrime) of Inhambane province, in a total of 120 samples. Samples were collected between January and June 2023 from local markets and producers. Samples were analysed for total aflatoxins using the lateral flow strip, AgraStrip® ProWATEX® (Romer Labs) method. Results showed that, from all matrices, the highest levels of aflatoxins were found in maize, with averages ranging from 369.2 (in Manjacaze) to 1,972.6 ug/kg (in Chokwe). Average aflatoxin levels in rice ranged between 1.2 (Chongoene) and 63.08 ug/kg (Manjacaze). Peanuts from the province of Inhambane were more contaminated than those from Gaza, with averages ranging from 5.6 (Manjacaze, Gaza) to 95 ug/kg (Inhambane). Considering that the maximum admissible levels for total aflatoxins recommended by the Codex Alimentarius Commission for cereals and pulses is 15 ug/kg, the level of aflatoxin contamination in food produced and consumed in southern Mozambique is high and constitutes a public health risk for the population. Therefore, risk mitigation strategies are urgently needed.
- Leguminous cover crops improve the profitability and the sustainability of rainfed olive (Olea europaea L.) orchards: from soil biology to physiology of yield determinationPublication . Correia, Carlos M.; Brito, Cátia; Sampaio, A.; Dias, Alberto; Bacelar, Eunice; Gonçalves, Berta C.C.; Ferreira, Helena; Moutinho-Pereira, José; Rodrigues, M.A.The olive sector has a crucial economic, social, cultural and ecological relevance in the Mediterranean region, where tillage and herbicides application still are generalized practices. However, these techniques oppose to the recommendations of UE policy. Thus, other methods are needed to reduce adverse environmental impacts and to improve biodiversity, soil carbon sink and fertility, to save fossil fuels and to increase yield and the safety and nutritional value of food products. Meanwhile, since Mediterranean basin is particularly vulnerable to climate change, including lower precipitation in summer, olive tree will experiment some hard changes, mainly under rainfed conditions. Therefore, we propose an adequate management of cover crops to shift tillage and herbicides, in order to minimize runoff and evaporation water losses, conserve soil moisture storage and promote the infiltration of water in soil. The experiment was carried out during 4 years on a commercial orchard (cv. Cobrançosa) in Northeast Portugal. The treatments laid out were: (1) ordinary tillage techniques (OT) used by local growers (two tillage trips per year); (2) cover crop with self-reseeding annual legume species (AL); (3) natural vegetation fertilized (NVF) with 60 kg N hm2 (as in OT); (4) natural vegetation (NV) left unfertilized. The results revealed that AL treatment is the best option, reaching 37, 53 and 95% higher cumulative yield than NVF, OT and NV, respectively, in a closely association with greater physiological performance during the summer, mainly evidenced by lower oxidative damage and by favourable changes in water status and net photosynthetic rate, due to lower stomatal and mesophyll limitations. Moreover, the AL covered soil presented considerable microbial diversity and enzymatic activities, which may contribute to promote and conserve soil quality and health, as well the stability of ecosystems. Thus, leguminous cover crops improve the profitability and the sustainability of rainfed olive orchards.