Control of fecal contamination and Escherichia coli O157:H7 on beef during slaughter and fermentation processes.

摘要

The effect of a pre-evisceration, skin-on carcass sanitation method for reducing bacterial contamination during slaughter of cattle was studied. The results indicated that reducing counts of aerobic bacteria on the hi to 3.6 log10 cfu/cm2 using chemical and thermal sanitation did not significantly reduce the bacterial Contamination beef carcass surfaces.;E. coli Biotype I and Enterococcus spp. on beef carcasses survived in similar profiles during storage Comparison of Petrifilm and most probable numbers (MPN) methods for enumeration of E. coli Biotype indicated that Petrifilm method was less sensitive for quantifying low levels of fecal contamination than the MPN method.;Spraying of inoculated beef carcasses with 2% lactic acid was more destructive on survival of E. coli Biotype I than on E. coli O157:H7 during storage. Tempering was ineffective for reducing the numbers of bacteria. Survival profiles of the pathogen and the indicator organism on the control carcasses were similar.;Pre-spraying inoculated beef carcasses with 5% Tween 20 solution prior to spraying with 2% lactic acid alone or in combination with 0.5% sodium benzoate was shown to improve the antimicrobial effect of the acid against E. coli O157:H7 during storage. Addition of 0.1% or 0.25% Tween 20 to buffered peptone water prior to stomaching significantly improved the recovery of the pathogen from excision samples taken from chilled beef carcasses.;Effects of manufacturing processes for Turkish fermented soudjouk [fermentation (with or without starter culture), post-fermentation cooking, and storage temperature] on the survival of E. coli O157:H7 were investigated. Results revealed that fermentation with a starter culture to pH 4.55 and a subsequent heating to 54°C internal product temperature yielded greater than 7 Log10 cfu/g reduction of the pathogen, whereas limited effect was observed from natural fermentation (pH 5.5) and the same cooking regime. The pathogen survived significantly better in soudjouk sticks stored at 4°C than at 21°C.