Inactivation of Escherichia coli O157:H7 by essential oil from Cinnamomum zeylanicum

Escherichia coli O157:H7 is a pathogen strain, which causes hemorrhagic colitis, hemolytic uremic syndrome and thrombotic thrombocytopenic purpura in humans. The control of bacterial cells in foods is an important factor to reduce foodborne diseases due to E. coli O157:H7. Assays to inactivate E. coli O157:H7 were carried out by using the cinnamon oil obtained by steam distillation for 6 hours. When E. coli O157:H7 cells were incubated at 37°C for 2 hours in the presence of 0.025 percent of the essential oil from cinnamon, a dramatic decrease was observed in the viable counts (from 10(7) to 3.10(4) CFU/mL-1). In the presence of 0.05 percent of the oil, most of cells were killed after 30 min, suggesting that the antimicrobial activity of essential oil is bactericidal against E. coli. The minimal inhibitory concentration of the essential oil from cinnamon was around 625 ppm against E. coli O157:H7 and E. coli ATCC 25921, around 1250 ppm against E. coli ATCC25922 and around 2500 ppm against E. coli ATCC11105.

Extending shelf life of fresh minced camel meat at ambient temperature by Lactobacillus dlbrueckii subsp. delbrueckii

Studies were conducted to stabilize minced meat by fermentation using mixed lactic acid bacteria cultures isolated from natural fermented foodstuffs and selected for their antimicrobial activity against some hazardous microorganisms. Fresh meat of camel purchased from the slaughterhouse of Rabat (Morocco) was minced separately with a meat mincer and supplied with 5 percent glucose, then inoculated with lactic acid bacteria. Microbiological analyses were carried out to determine standard plate count (SPC), staphylococci, coliforms, enterococci, and lactic acid bacteria. All analyses were determined after 1, 2, 3, 4 and 7 days during the storage. Results showed that a low pH of 4.0-4.2 can be achieved (within 3 days at 22ºC), with a drastic reduction in SPC, coliforms, enterococci and staphylococci. Results suggested that the use of lactic acid bacteria would help in preserving fresh camel meat for extended periods at 22ºC.