Orientador: Prof. Dr. Miguel Machinski Junior

 Data da Defesa: 18/12/2017



Wheat is one of the major important cereals produced and consumed in Brazil, as it is an ingredient for various types of food products such as bread, pasta and biscuits, among others. However, wheat is a cereal that could be infected by toxigenic fungi and contaminated with mycotoxins. Deoxynivalenol (DON), trichothecene of group B, is produced by fungi of the genus Fusarium spp, mainly by F. graminearum and F. culmorum and is the most prevalent mycotoxin in this crop. The pastas are widely consumed by the population, and as wheat flour is used as raw material, could have the presence of mycotoxin in this product also, even after the manufacturing process. Exposure to mycotoxins occurs through the ingestion of contaminated foods, were their presence is a difficult problem to avoid and because they are stable at processing temperatures. Therefore, there is a risk to the health of the population, evidencing the importance of monitoring and research of occurrence. Acute DON intoxication demonstrates the following toxic syndrome: nausea, vomiting, anorexia, inflammation of the gastrointestinal tract, gastroenteritis, inhibitor of protein synthesis and cell division. Chronic exposure to this mycotoxin has been linked to glomerulonephritis due to increased immunoglobulin A. The International Agency for Research on Cancer (IARC) has classified DON in group 3, non-carcinogenic to humans. Considering the importance of high consumption of wheat flour and its derivatives, the objectives of this study were to evaluate the occurrence of DON in wheat flour in Paraná state, Brazil; to investigate exposure rates of teenagers, adults and the elderly to this mycotoxin due to intake of wheat flour-based foods; and to investigate the occurrence and estimate the exposure of the population to the DON in samples of pasta marketed in the Paraná state at different seasons of the year. The samples were collected weekly by agents from state and municipal health surveillance agencies in municipalities distributed among the 22 “regional health departments” of Paraná state, Brazil, between January and October of 2016. DON determination was performed by solid phase extraction and identification and quantification by ultra-high proficiency liquid chromatography with diode-array detection. Of the 172 samples of wheat flour analyzed, 77.9% were contaminated with DON in concentrations ranging from 73.50 to 2794.63 μg kg-1 . Four samples exceeded the maximum tolerated level according to the National Health Surveillance Agency - ANVISA, and six the limit determined by the European Commission. Females of all groups were considered exposed to DON at higher levels when compared to males in regard of consumption of breads and pastas. The maximum probable daily intake for the teenagers were 1.28 and 1.20 μg kg-1 body-weight day-1 for the females and males, respectively, which demonstrates that this population is at an increased risk of exposure to DON due to consumption of wheat flour-based foods in Brazil. In the analysis of 82 pasta samples, 57 of them had the presence of mycotoxin with a mean contamination of 230.6 ± 164.32 (75.4 - 1146.0) μg kg-1 . Only one sample of pasta had DON concentrations above Brazilian and European legislation. Even though the winter season had the highest mean contamination, 174.9 μg Kg-1 , there was no significant difference between the DON concentrations found in the 4 seasons (summer, autumn, winter and spring). No probable daily intake of DON in pasta, was shown to be above the value established as safe and did not demonstrate health risk. The occurrence of DON in wheat flour samples marketed in the Paraná State, Brazil, was high and the risk assessment demonstrated that female teenagers 11 presented higher exposure to DON. Intake of DON, present in foods derived from wheat flour, in teenagers of both genders, which indicates this specific group of the assessed population is at an increased risk. The seasons of the year had no influence on the concentrations of DON in the analyzed pasta samples and the exposure by the consumption of this food did not present a risk to the health of the population. Wheat flour and derivatives are important foods frequently present in food, and the presence of mycotoxins is recurrent and difficult to control, constant monitoring is necessary in order to assess the health risks of the food exposed population wheat derivatives. Keywords: Deoxynivalenol; Exposure assessment; Fusarium graminearum; mycotoxins; wheat-based products.


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