Gram-positive bacteria were more sensitive than Gram-negatives against our analyzed Essential Oils (EOs). Yeasts were more sensitive than bacteria against our analyzed EOs. Oregano and thyme EOs showed the highest antimicrobial activity.
Background. Plant-derived essential oils (EOs) have shown remarkable antimicrobial potential against spoilage and pathogenic microorganisms in meat and meat products. The aim of this study was to investigate the influence of oregano EO on the inhibition of Salmonella Enteritidis, Listeria monocytogenes and Staphylococcus aureus in an internal mixture of "Alheira" during storage. Material and methods. Different concentrations of oregano EO (4%, 1.5%, 0.5%, 0.195% and 0.0975%) were evaluated against the selected pathogens during 21 days of storage at 4°C. The pH and water activity values and lactic acid bacteria (LAB) counts were also evaluated. Finally, sensory assessment was performed. Results. The antibacterial effect varied according to the oregano EO concentration used, and target pathogen. Oregano EO at 4% demonstrated the highest antimicrobial activity against all the pathogens tested. The lowest concentrations used (0.195% and 0.0975%) resulted in ~2-3 log reduction, but only for L. monocytogenes after 21 days of storage. Counts of LAB were ~10 9 CFU/ml for all samples and no differences in the pH and a w values were detected between samples. However, at a concentration of 0.195%, Oregano EO had a negative impact on consumer acceptance of "Alheira". Conclusion. These results could be interesting for the meat industry, as a starting point for other studies that have now to concentrate on strategies to "mask" unpleasant sensorial alterations caused by EOs in "Alheira" and helping the industry to ensure the microbiological safety of its products.
The monitorization of carcass surfaces contamination along the slaughter lines enables the verification of the slaughter operations hygiene and the good manufacturing practices. Pork meat is a common source of human non-typhoidal salmonellosis, one of the most frequently reported foodborne illnesses worldwide. This study aimed to gather data on microbial loads in carcass surfaces in two slaughterhouses, before and after evisceration. Salmonella enterica search was made after evisceration, due to the frequent reference to pork as being a common carrier of this microorganism. The contamination of carcass surfaces was evaluated by delimitation of surface area with sterilized templates (100 cm2), and sampled by gauze swabs. Enumeration of total aerobic mesophilic microorganisms, Enterobacteriaceae, and Escherichia coli was performed. The detection of Salmonella was performed for carcass surfaces after evisceration, and from animal liver and floor drains (environmental). Significant differences (p < 0.05) were observed for mesophilic microorganisms, Enterobacteriaceae, and E. coli counts on the external surfaces, with higher counts after evisceration. The neck and abdominal area presented higher levels for mesophilic microorganisms, Enterobacteriaceae and E. coli, and a high prevalence of Salmonella. Salmonella was detected only in one of the studied slaughterhouses; 19 out of 259 analysed carcass samples were positive for Salmonella (7.3%). Salmonella was also detected in two livers and in two floor drains. A collection of 52 Salmonella isolates (44 from carcasses, 5 from livers, 3 from drains) was gathered. Three serovars of Salmonella were identified (Typhimurium 4,5:i- , Wernigerone and Derby), and 53.8% of isolates were multidrug-resistant. The results demonstrate the need for continuous improvement of slaughtering operations and good manufacturing practices, to ensure food safety of pork produced in Portugal.
No abstract
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.