This is a retrospective study describing data on the microbiological conditions of food and water obtained from analysis reports issued by the Central Laboratory of the Federal District (LACEN-DF), and information on foodborne disease outbreaks investigated by the Office of Water and Food Borne Diseases of the Federal District (NATHA), Brazil, between 2000 and 2010. A total of 4576 analysis reports were evaluated, from which 92.9% of monitoring samples and 7.1% of samples suspected to be involved in outbreaks. Of the total number of samples, 630 did not comply with Brazilian legislation (rejected). Ready-to-eat food, milk/dairy products, water, spices/seasonings, and ice cream/sorbets had the highest rejection rates among the monitoring samples (18.9–11%), with the first two groups having the highest rates among the outbreak samples (23.5 and 21.7%). Minas cheese showed to be the food with the highest rejection rate among the samples analyzed by the LACEN-DF. About 9% of the food samples were rejected due to thermotolerant coliforms and/or coagulase-positive staphylococci, and 10.5% of the water samples were rejected due to Pseudomona aeruginosa. Ready-to-eat food were the main foods involved in the foodborne disease outbreaks investigated by NATHA (51.3% of the 117 outbreaks with the food identified) and Bacillus cereus the most identified etiologic agent (41.2% of the 80 outbreaks with the agent identified). This study indicated that microbiological surveillance programs should focus on ready-to-eat food to prevent the occurrence of foodborne disease outbreaks in the region.

This work studied the effect of composition of powders and water content on mixture quality (MQ) of three binary powder mixtures with good (salt/paprika or salt/sugar) or poor mixing (salt/oregano) behaviour. The mixing behaviour was assessed using coefficient of variation. Results showed that mixture composition did not influence the MQ of sugar/salt and paprika/salt within 20–80% salt content range but it did influence the MQ of oregano/salt with a progressive dis-improvement in MQ with higher oregano content and also for low concentrations of 1% salt. Water content did have an effect on mixing behaviour. When paprika with high water activity (aw) was mixed with salt, the time required to reach good MQ was longer because of the increased cohesiveness and when oregano with high aw was mixed with salt it displayed improved MQ because salt particles were able to stick onto the larger oregano particles and reduced segregation.

The antimicrobial effect of water extracts of sumac (Rhus coriaria L.) at concentrations of 0.1%, 0.5%, 1.0%, 2.5% and 5.0% (w/v), non-neutralized and after neutralization to pH 7.2 +/- 0.1, was studied on the growth of 12 bacterial strains (six Gram positive strains and six Gram negative strains), mostly food borne including pathogens. It was found to be effective against all the test organisms with Gram positive strains being more sensitive than Gram negative strains. Significant differences (P<0.01) were found among the bacteria and between the non-neutralized and neutralized extracts with non-neutralized being more effective against all the bacteria. The minimal inhibitory concentration (MIC) of the extract for each bacterial strain was studied by a gradient plate method. Among the Gram positive organisms, Bacillus species (Bacillus cereus, Bacillus megaterium, Bacillus subtilis, and Bacillus thuringiensis) were found to be the most sensitive showing MICs of 0.25-0.32% (after 24 h incubation) followed by Staphylococcus aureus (0.49%), while Listeria monocytogenes was found to be the least sensitive demonstrating a MIC of 0.67%. Of the Gram negative organisms, Salmonella enteritidis was found to be the most resistant with a MIC of 0.67% followed by Escherichia coli Type I, E. coli O157:H7, Proteus vulgaris and Hafnia alvei having MICs of 0.63%, 0.60%, 0.55% and 0.45%, respectively; whereas Citrobacter freundii was found to be the least resistant surviving up to 0.42%. Some loss of antimicrobial activity was, however, observed after incubation for 3 days. Bacteriostatic/bactericidal effects of sumac, as studied by enumerating survival by the viable count technique after 1 h direct contact of each microorganism with various concentrations of sumac extract, revealed a 4-5 log cycle reduction in Bacillus spp. and 2-3 log cycle reduction in other bacteria tested with 1.0% sumac extract.