ABSTRACT
BACKGROUND: Mercury, in particular its most toxic form methylmercury, poses a risk to public health. Dietary methylmercury exposure is mainly by fish, and it can vary with fish contamination and by dietary habits of the population. This study aimed to quantify total mercury levels in different fish from Brazil and to estimate Brazilian exposure to methylmercury by fish consumption. METHODS: Total mercury occurrence was investigated in 18 different fish species by atomic absorption spectrometry with thermal decomposition and gold amalgamation. Dietary exposure to methylmercury was estimated by a deterministic method for different groups considering consumption by sex, different Brazilian geographical regions and habitat (rural or urban). RESULTS: Carnivorous fish showed higher levels of mercury (0.01 to 0.93â¯mg/kg) compared to non-strictly carnivorous fish (<0.01 to 0.30â¯mg/kg). Farmed fishes showed significantly lower levels compared to wild fish. Mean Brazilian fish consumption achieves FAO/WHO health recommendation of about two portions of fish per week. However, there is a large difference between fish consumption at urban and rural homes and among Brazilian geographic regions. These differences in consumption impacted estimated methylmercury intake that was higher in the Northern (1.85⯵g/kg bw week) and in the Northeastern (0.72⯵g/kg bw week) regions and also by rural population (1.08⯵g/kg bw week). These values were compared with the toxicological reference dose for neurotoxicity of 1.6⯵g/kg bw week. CONCLUSION: Even though total levels of mercury in fish were lower than Brazilian and international legislations, in the Northern Brazilian region methylmercury intake overpassed the toxicological reference dose for neurotoxicity and in rural areas it achieved 68% of this reference dose.
Subject(s)
Metals, Heavy/analysis , Methylmercury Compounds/analysis , Animals , Brazil , Dietary Exposure , Environmental Monitoring , Fishes , Food Safety , Humans , Risk AssessmentABSTRACT
O leite é um alimento nutritivo e perecível, tornando imprescindível a utilização de Boas Práticas de Fabricação (BPF) para sua produção segura. O objetivo do trabalho foi propor melhorias das BPF à um pequeno laticínio da Mesorregião Centro Fluminense que processa leite cabra. A partir de visitas técnicas, foram coletadas amostras de alimentos para realização de análises físico-químicas e microbiológicas bem como foi feito um diagnóstico das condições de produção por meio de uma lista de verificação. Diante das inadequações encontradas que incluíram desvios na estrutura predial, organização do laticínio, higiene e controle de qualidade da matéria-prima, produto final e seu transporte até os pontos de venda, foi elaborado um plano de ação para melhoria das BPF baseado no grau de importância e custo. Foi elaborado ainda alguns Procedimentos Padrão de Higiene Operacional e revisão do Manual de BPF do estabelecimento. Esta ação contribuiu para conscientizar o laticínio sobre a importância de avaliação constante e melhoria das BPF dos produtos lácteos caprinos.
Subject(s)
Humans , Animals , Good Manufacturing Practices , Food Safety/methods , Milk/microbiology , Milk/chemistry , Cheese/analysis , Cheese/microbiology , Goats , ChecklistABSTRACT
Pork loin and leg were evaluated 24h after slaughter and during refrigerated (5°C) and frozen storage for microbial counts, pH, total volatile base nitrogen (TVB-N), thiobarbituric acid reactive substances (TBARS) and bioactive amines. Spermine was the prevalent amine in fresh pork loin and leg, followed by spermidine and agmatine. During refrigerated storage, pH, TVB-N, mesophilic and psychrotrophic counts increased and no changes (p<0.05) were observed on polyamines; however putrescine, cadaverine and histamine were produced and accumulated throughout storage. Principal Component Analysis (PCA) and Hierarchical Cluster Analysis (HCA) for all parameters indicated a shelf life of 8days for both cuts, which was also coherent with safety regarding histamine levels. During frozen storage, there was no change on amines and pH, TVB-N decreased, and TBARS increased. None biogenic amine was produced. PCA and HCA were not able to classify frozen pork based on the analyzed parameters; however, a shelf life of 90days was suggested for the frozen cuts based on lipid oxidation.
Subject(s)
Amines/analysis , Freezing , Red Meat/standards , Refrigeration , Animals , Food Microbiology , Food Storage/methods , Histamine/analysis , Hydrogen-Ion Concentration , Male , Red Meat/microbiology , Sus scrofa , Thiobarbituric Acid Reactive Substances/analysisABSTRACT
Aromatic bisamidines have been proved to be efficient compounds against Leishmania spp. and Pneumocystis carinii. Although the mode of action is still not known, these molecules are supposed to be DNA minor groove binders (MGBs). This paper describes a molecular modelling study for a set of MGBs in order to rank them through their complementarity to the Dickerson Drew Dodecamer (DDD) according to their interaction energies with B-DNA. A comparative molecular field analysis (CoMFA) has shown the importance of relatively bulky positively charged groups attached to the MGB aromatic rings, and small and negatively charged substituents into the middle chain. Models were obtained for DNA denaturation related to H-bonding processes of binding modes. Validation of the model demonstrated the robustness of CoMFA in terms of independent test set of similar MGBs. GRID results allotted bioisosteric substitution of z.sbnd;Oz.sbnd; by z.sbnd;NHz.sbnd; in furan ring of furamidine and related compounds as being capable to enhance the binding to DDD.
