Cíntia Silva Minafra e Rezende

Microbiological quality and other characteristics of refrigerated chicken meat in contact with cellulose acetate-based film incorporated with rosemary essential oil

Antimicrobial active packaging delays or inhibits microorganism growth in packed products, and it can be used in a variety of food systems. The objective of the present research was to develop packaging incorporated with natural antimicrobial agents (active film). The effects of the active film on the spoilage, pathogenic microorganism counts, pH and color of the refrigerated chicken breast cuts were analyzed. Cellulose acetate-based active films incorporating two concentrations (20% and 50%, v/w) of rosemary (Rosmarinus officinalis L.) essential oil were manufactured and placed in contact with the chicken breast cuts for six days. An analysis of variance and mean comparison tests (Tukeys test, p<0.05) were performed on the results. The films that contained 20% essential oil and were intercalated with chicken breast samples did not demonstrate significant effects on the control of psychrotrophic or total coliform microorganisms during the storage period; however, the films incorporated with 50% essential oil demonstrated efficacy toward the control of coliforms during the storage of the samples (6 days, 2 ± 2oC). The pH was related to the psychrotrophic microorganism count and was not influenced by the treatment. The color was not influenced by the time of storage or the treatment. The results demonstrate that active films incorporating 50% rosemary essential oil are effective at controlling certain microorganisms in chicken breast cuts.

Association of TLR4 polymorphisms with subclinical mastitis in Brazilian holsteins

The identification of dairy cows with greater or lower potential to develop mastits has been pursued for many years among different segments of the milk industry, including governmental organizations. Genomic studies have suggested that Single Nucleotide Polymorphisms (SNPs) within the pattern recognition receptors (PRR) could lead to different responses to pathogens, and consequently result in mastitis resistance or susceptibility. To investigate whether toll like receptor 4 (TLR4) gene is associated with subclinical mastitis in Holstein cows from a property in the state of Goiás, Brazil, TaqMan allelic discrimination and somatic cell count were performed. One hundred and fifty milk samples were analyzed for SCC and centesimal composition. Twenty percent of those samples with SCC above 200,000 (n=13) were screened for real-time PCR identification of microorganisms and blood samples were genotyped for TLR4 SNPs. There was a higher prevalence of Gram-positive bacteria in the analyzed samples (88.9%) and animals that had the combined genotypes AACCCC, GGTCGG and GACCGC presented the lowest somatic cell scores, and consequently those genotypes have the potential to be applied as molecular markers for assisted animal selection to improve milk quality.

PCR and ELISA (VIDAS ECO O157(®)) Escherichia coli O157:H7 identification in Minas Frescal cheese commercialized in Goiânia, GO.

Escherichia coli O157:H7 has been incriminated in food poisoning outbreaks and sporadic cases of hemorrhagic colitis and hemolytic uremic syndrome in many countries. Considering the high susceptibility of Minas Frescal cheese to contamination by E. coli O157:H7, the aim of this study was to determine the occurrence of this pathogen through PCR (Polymerase Chain Reaction) and ELISA (VIDAS ECO O157®, bioMérieux, Lyon, France) test. Thirty cheese samples manufactured by artisan farmhouse producers were collected from open-air markets in Goiânia and thirty from industries under Federal Inspection located in Goiás State which trade their products in supermarkets in Goiânia. E. coli O157:H7 was detected in 6.67% samples collected in open air markets using ELISA, and 23,33% with PCR. The pathogen was not detected in samples from industries under Federal Inspection.

Performance and intestinal health of broilers inoculated with nalidixic acid-resistant Salmonella Typhimurium and treated with organic acids

An experiment with 630 one-day-old chicks experimentally inoculated with Salmonella Typhimurium was performed to evaluate the effects of an organic acid blend (benzoic, fumaric and 2-hydroxi-4-methylltio-butanoic - HMTBa) on intestinal health and performance. The experimental challenge with Salmonella Typhimurium occurred in two different routes of administration: via crop on the first day after hatching, and via feed, offered from seven to 14 days of age. These groups were treated with organic acids in a 3 × 2 (agent versus acid) factorial arrangement. Chicks treated with organic acids had higher weight gain, mean live weight and better feed conversion at 14 days of age, and higher weight gain at 28 days of age. Chicks treated with organic acids inoculated via crop had higher duodenum villi height than animals of the control group. Jejunum villi were higher in chicks of the negative control group compared with birds supplemented with organic acids. Small intestine pH in chicks of the inoculated group was lower compared with control group throughout the trial period. HMTBa acid in the dosage of 0.4% improves intestinal health and performance when nalidixic acid resistant Salmonella Typhimurium is experimentally inoculated.

Sensory profile of warmed-over flavour in tenderloin from steers supplemented with alpha-tocopherol

The objective of the present study was to evaluate the occurrence of warmed-over flavour (WOF) in cooked tenderloin and the influence of alpha-tocopherol on its inhibition. A total of 24 animals were confined, 12 of which received 1200 mg/head/day of alpha-tocopherol acetate for 90 days. Longissimus dorsi muscle cuts (tenderloin) were obtained for sensory profile assessment by nine trained tasters. The tasters evaluated the taste of the meat based on four general and 18 specific attributes. The results of the evaluations were analysed with ANOVA, post-hoc tests of the means (Tukey tests), and principal component analysis (PCA). There was no significant difference in the WOF between the cuts of meat from the supplemented and non-supplemented animals. However, as the refrigeration period increased, there was a decrease in the intensity of the umami and sweet taste attributes and the flavour and aroma of the roast meat as well as an increase in the intensity of the oxidised vegetable oil flavour and the aromas of fish, hard-boiled egg, flaxseed oil, and oxidised vegetable oil. The samples that had been stored for one day were characterised by PCA as having sweet and umami tastes and the flavour and aroma of roast meat, whereas after three days, the samples were classified as having sour and bitter tastes, the flavour of chicken and nuts, and the aroma of fish. The typical sensory attributes desirable for roasted meat decreased in intensity during the three days of storage after cooking, whereas the intensity of unpleasant (oxidative) attributes for the consumer increased.

Identification of Salmonella sp. in Curraleiro Pé-Duro cattle raw milk

The microbiological quality of raw milk can be directly affected by animal health, hygiene procedures performed during milking and product storage condition. Faced with the need to characterize the microbiological aspects due to the milk production of cattle herd of CurraleiroPe-Duro breed, there were evaluated 226 samples of raw milk collected in the period of january 2013 to january 2014, for research of Salmonella sp.. The analytical tests were performed in Multi-User Laboratory of Microbiology Food Research Center at Veterinary Medicine School of the Federal University of Goias. According to the results in this study it was identified the presence of Salmonella sp., serovar Heidelberg and Schwarzengrund. Although this microorganism comprise the normal intestinal flora of humans and warm-blooded animals, be eliminated in feces and consequently promote environmental contamination and other animals, the identification of Salmonella in raw milk results the need for control in obtaining the milk process, storage and processing procedures of dairy products to ensure safety to consumers.