Abstract There are very few studies evaluating the exposure of the general population to food colours. This study aimed to estimate the Theoretical Maximum Daily Intake (TMDI) by the Brazilian population of four rather seldom-used synthetic food colours: Azorubine, Erythrosine, Indigotine, and Ponceau 4R. The study was conducted using data from the two most recent National Household Budget Surveys (carried out in 2008/2009 and 2017/2018). The study covered the country’s population, sorted into the following groups: gender, geographic region, and age (among people older than 10 years). The results show that the mean TMDI (mg/day) does not exceed the Acceptable Daily Intake (ADI) in any population group for any of the food colours. The highest values found were 12.5% of the ADI for Erythrosine in 2008/2009 and 4% in 2017/2018. A decrease in the mean TMDI was observed for all food colours comparing 2008/2009 and 2017/2018. Intake increases with decreasing age, adolescents being the group with the highest mean TMDI. When considering the prevalence of food consumption instead of the mean consumption, TMDI gets closer to the ADI, reaching 79% of the ADI of Erythrosine for adolescent females. The intake of these food colours proved to be within the recommended levels.

Bactérias produtoras de atividade antimicrobiana foram identificadas entre 86 isolados de ambientes aquáticos da Bacia Amazônica. Destes, 59 isolados (68.6%) apresentaram atividade antimicrobiana contra pelo menos uma bactéria indicadora. A atividade inibitória foi principalmente observada contra bactérias Gram-positivas, como Listeria monocytogenes e Bacillus cereus. As substâncias antimicrobianas produzidas por 19 linhagens que demonstraram maior atividade inibitória foram parcialmente caracterizadas, apresentando resistência térmica até 100°C e resistência parcial ao tratamento proteolítico. Algumas substâncias foram parcialmente inativadas somente quando tratadas com ácido tricloroacético ou com pronase E na concentração de 2 mg ml-1. A detecção da atividade antimicrobiana em géis de poliacrilamida mostrou que os compostos apresentaram peso molecular inferior à 14 kDa. Várias linhagens apresentaram atividade antibacteriana, que em alguns casos estaria relacionada com peptídios antimicrobianos. O potencial destes microrganismos para produzir substâncias antimicrobianas é grande e merece ser mais explorado.

Bacteria producing antimicrobial activity were identified among 86 isolates from aquatic environments of Brazilian Amazon Basin. Antimicrobial activity against at least one indicator strain was detected for 59 isolates (68.6%). Inhibitory activity was mostly against Gram-positive bacteria, such as Listeria monocytogenes and Bacillus cereus. The antimicrobial substances produced by 19 strains that showed higher inhibitory activity were partially characterized. These antimicrobial substances showed thermal resistance for up to 100°C and partial resistance to proteolytic treatment. Some antimicrobials were partially resistant to pronase E at 2 mg ml-1 or to treatment with trichloroacetic acid. Detection of antimicrobial activity on polyacrylamide gels revealed that the molecular weight of the compounds was lower than 14 kDa. Several strains showed antibacterial activity, which in some cases appear to be related to antimicrobial peptides. The potential of these microorganisms to produce useful antimicrobial compounds is great and must be better explored.