RESUMEN
In this study the 13 polycyclic aromatic hydrocarbons (PAHs) identified as being genotoxic and carcinogenic by the Joint FAO/WHO Expert Committee on Food Additives (JECFA) were determined in different brands of soybean oils available on the Brazilian market, totalling 42 samples. A solid-phase extraction (SPE) method for sample clean-up with a C18 cartridge, followed by reversed-phase HPLC with fluorescence detection, was used for determination. The method showed good recoveries for most PAHs studied with values between 74% and 111%. Good intra- and inter-day precisions (0.5 < RSD < 11.9) and high correlation coefficients (r(2)> 0.999) were obtained. The presence of PAHs was detected in all 42 samples with mean summed PAH levels ranging from 10.4 to 112.0 µg kg(-1). The mean and maximum dietary exposures for total PAHs were estimated as 12.4 and 19.1 ng kg bw(-1) day(-1), respectively.
Asunto(s)
Dieta , Exposición a Riesgos Ambientales , Contaminación de Alimentos/análisis , Hidrocarburos Policíclicos Aromáticos/análisis , Aceite de Soja/química , Brasil , Cromatografía Líquida de Alta Presión , Límite de DetecciónRESUMEN
The effect of phosphine on Salmonella enterica serotype Enteritidis inoculated in culture medium and in black pepper grains (Piper nigrum), as well as on the reduction of the microbial load of the dried and moisturized product, was verified. The postfumigation effect was verified in inoculated samples with 0.92 and 0.97 water activity (a(w)) exposed to 6 g/m(3) phosphine for 72 h, dried to 0.67 a(w), and stored for 24, 48, and 72 h. No decreases were observed in Salmonella Enteritidis populations in culture medium when fumigant concentrations up to 6 g/m(3) were applied for 48 h at 35°C. However, the colonies showed reductions in size and atypical coloration as the phosphine concentration increased. No reduction in Salmonella counts occurred on the inoculated dried samples after fumigation. On the other hand, when phosphine at concentrations of 6 g/m(3) was applied on moisturized black pepper for 72 h, decreases in Salmonella counts of around 80% were observed. The counts of total aerobic mesophilic bacterium populations of the dried and moisturized black pepper were not affected by the fumigant treatment. The results of the postfumigation studies indicated that Salmonella Enteritidis was absent in the fumigated grains after drying and storage for 72 h, indicating a promising application for this technique. It was concluded that for Salmonella Enteritidis control, phosphine fumigation could be applied to black pepper grains before drying and the producers should rigidly follow good agricultural practices, mainly during the drying process, in order to avoid product recontamination. Additional work is needed to confirm the findings with more Salmonella serotypes and strains.
Asunto(s)
Medios de Cultivo/química , Conservación de Alimentos/métodos , Fumigación/métodos , Fosfinas/farmacología , Piper nigrum/microbiología , Salmonella enteritidis/efectos de los fármacos , Recuento de Colonia Microbiana , Viabilidad Microbiana , Salmonella enteritidis/crecimiento & desarrollo , Factores de Tiempo , Agua/metabolismoRESUMEN
Diflubenzuron (DFB) is used to control ectoparasitic infestation by inhibiting larvae development in the manure and feces of treated animals. It is also currently been used to control tick infestations. In this study, milk and tissues from cattle treated orally with DFB for a 77-120 day period with a commercial product containing the compound were analyzed for the presence of residues. DFB residues were determined by using extraction with acetonitrile, cleanup with C18 SPE and chromatographic analysis by HPLC with UV detection (254nm). DFB was not detected in any of the analysed samples (<0.006mg kg-1 for fat, <0.014mg kg-1 for muscle, <0.015mg kg-1 for kidney, <0.016mg kg-1 for liver and <0.0006mg kg-1 for milk). In this manner, the use of this compound, according to the manufacturer's suggested doses may result in cattle milk, liver, kidneys, fat and muscles being considered safe regarding the presence of DFB residues.
O diflubenzuron (DFB) é um inibidor de desenvolvimento de insetos que inibe a síntese de quitina com atividade ovicida e larvicida e está sendo utilizado na pecuária para o controle do carrapato. Leite e tecidos provenientes de bovinos tratados por um período de 77 a 120 dias com um produto comercial contendo DFB foram analisados quanto à presença de resíduos. Os resíduos de DFB foram determinados utilizando-se extração com acetonitrila, limpeza por SPE C18 e cromatografia líquida de alta eficiência com detecção por UV (254nm). DFB não foi detectado em nenhuma das amostras analisadas (<0.006mg kg-1 para gordura, <0,014mg kg-1 para músculo, <0,015mg kg-1 para rim, <0,016mg kg-1 para fígado e <0.0006mg kg-1 para leite). Dessa forma, a utilização do princípio ativo conforme recomendado pelo fabricante e em níveis suficientes para se obter o efeito larvicida desejado deve resultar em leite, fígado, rins, gordura e músculos que podem ser considerados seguros para o consumo em termos da presença DFB.
Asunto(s)
Animales , Bovinos , Diflubenzurón/administración & dosificación , Diflubenzurón/química , Diflubenzurón/síntesis química , Epidermis/anomalías , Epidermis , Insectos/citología , Insectos/químicaRESUMEN
The daily intakes of benzoates and sorbates from selected food categories were estimated in Brazil in 1999. The Budget method was used as a first screening procedure for the estimation of the safety aspects of the maximum permitted levels of benzoates and sorbates established by the Brazilian food legislation. This screening indicated that benzoates should be further investigated. In a second step, the daily intakes of these preservatives were assessed by combining measured levels of these additives with national food consumption data derived from a household economic survey and a packaged good market survey. Benzoate and sorbate levels in soft drinks, fruit juices, margarine, yoghurt and cheese were determined by HPLC with a photodiode array detector (detection at 228 nm for benzoic acid, 260 nm for sorbic acid). The estimated intakes of benzoates and sorbates for the average consumer were below the ADIs, ranging from 0.3 to 0.9 and 0.2 to 0.3 mg kg(-1) body weight, respectively. Soft drinks were identified as the main source of benzoates representing >80% of the estimated intake.