Luiza Pieta

Chemical and sensory evaluation of dark chocolate with addition of quinoa (Chenopodium quinoa Willd.)

Quinoa (Chenopodium quinoa Willd) is a good source of vitamin E containing high quality protein. A dark chocolate with the addition of 12, 16 or 20% quinoa was developed. The protein concentration of the products increased as the percentage of quinoa increased. The product containing 20% quinoa showed only 9% increase in vitamin E, while the quantity of polyphenols decreased from 23.5 to 18 μmol pirocatechin/g. The amount of essential amino acids was improved in samples containing quinoa. Cysteine, tyrosine and methionine increased by 104, 72, 70%, respectively in chocolate containing 20% quinoa. The amino acid pattern was as per WHO standards, which was adequate to human needs. The chocolate with quinoa was approved by 92% of the sensory panel. All the samples showed an index of acceptance above 70%. Quinoa could be used at the levels evaluated in this study adding its potential health benefit to the dark chocolate.

Occurrence of Salmonella spp. and generic Escherichia coli on beef carcasses sampled at a brazilian slaughterhouse

A total of 120 beef carcasses were analyzed during processing at a slaughterhouse in southern Brazil. The carcasses were sampled by swab at three different steps of the slaughter line and then they were tested for Salmonella and E. coli. The Salmonella isolates were also examined for antimicrobial susceptibility. Salmonella prevalence distribution was modeled and the probability of contamination was simulated using @Risk program and 10,000 interactions. Results demonstrated that 4 beef carcasses (3.3%) were positive for Salmonella only in the first point. The six isolates of Salmonella were classified: S. Newport (n = 3), S. Saintpaul (n = 2) and S. Anatum (n = 1). No Salmonella strains exhibited resistance to any of the antimicrobials tested. As expected, the most contaminated point with E. coli was the first point (hide), presenting counts from 0.31 to 5.07 log cfu/100 cm2. Much smaller E. coli counts were observed in the other points. Results indicated low levels of Salmonella and E. coli on the beef carcasses analyzed and also low probability of contamination of the carcasses by Salmonella, suggesting adequate microbiological quality.

Comparative transcriptomic analysis of Listeria monocytogenes reveals upregulation of stress genes and downregulation of virulence genes in response to essential oil extracted from Baccharis psiadioides

Listeria monocytogenes is a pathogenic microorganism in humans and is frequently transmitted by food. Methods to control the presence of Listeria in foods are necessary. In the present study, transcriptomics of L. monocytogenes grown in the presence of essential oil extracted from Baccharis psiadioides were studied by RNA sequencing and reverse transcription quantitative polymerase chain reaction (RT-qPCR) experiments. The results obtained indicate that essential oil of B. psiadioides has potential bacteriostatic activity at the concentration tested, affecting Listeria cells functioning and development. Responses of the microorganism included upregulation of stress genes and downregulation of virulence genes, such as actA, hly and prfA, indicating a decrease in virulence and in the capacity of the microorganism to cause infection. Thus, the results presented here allow us to conclude that B. psiadioides essential oil may be an alternative means of controlling microorganisms proliferating in foods.

Complete Genome Sequence of Enterococcus faecalis Strain P8-1 Isolated from Wild Magellanic Penguin (Spheniscus magellanicus) Feces on the South Coast of Brazil.

ABSTRACT Enterococcus faecalis strains have a ubiquitous nature that allows them to survive in different niches. Studies involving enterococci isolated from marine animals are scarce. Therefore, in this study, we report the complete genome sequence of E. faecalis strain P8-1 isolated from feces of a Magellanic penguin on the south coast of Brazil.

Complete Genome Sequences of Two Listeria monocytogenes Serovars, 1/2a and 4b, Isolated from Dairy Products in Brazil

ABSTRACT Listeria monocytogenes is the foodborne pathogen responsible for a bacterial infection called listeriosis. Here, we present the whole-genome sequences of two L. monocytogenes serovars, 1/2a and 4b, which are considered the most prevalent in food processing plants and listeriosis outbreaks, respectively.

Draft Genome Sequence of Enterococcus faecalis Strain F165 Isolated from a Urinary Tract Infection

ABSTRACT We report here a draft genome sequence of Enterococcus faecalis strain F165 isolated from a urine specimen in South Brazil. The genome size was 3,049,734 bp, with a G+C content of 37.38%, and genes related to antimicrobial resistance and adherence were found in the strain. These findings are consistent with pathogenesis of E. faecalis species.

Draft Genome Sequence of Brazilian Escherichia coli Uropathogenic Strain E2

ABSTRACT Escherichia coli is a common pathogen recovered from cystitis infections. In this report, we announce the draft genome sequence of strain E2 isolated from the urine specimen from a female patient in South Brazil. The genome assembly has 5,081,209 bp, a G+C content of 50.57%, and virulence factors associated with both enteroaggregative and uropathogenic E. coli strains.