Dorsa W J, Cutter C N, Siragusa G R
United States Department of Agriculture, Agricultural Research Service, Roman L. Hruska U.S. Meat Animal Research Center, Clay Center, Nebraska 68933-0166, USA.
J Food Prot. 1998 Sep;61(9):1109-18. doi: 10.4315/0362-028x-61.9.1109.
The long-term effectiveness of several beef-carcass surface-tissue (BCT) wash interventions on the microbiology of ground beef produced from this tissue was determined. BCT was inoculated with bovine feces containing one of two different levels (ca. 4 or 6 log CFU/ml) of Escherichia coli O157:H7, Listeria innocua, Salmonella typhimurium, and Clostridium sporogenes. The BCT was then subjected to one of several treatment washes: 2% (vol/vol) DL-lactic acid (LA), 2% (vol/vol) acetic acid (AA), 12% (wt/vol) trisodium phosphate (TSP), hot water (HW; 74 +/- 2 degrees C at the tissue surface), or water (WW; 32 +/- 2 degrees C at the tissue surface). A control group was left untreated. After treatments, BCT was held at 4 degrees C for 24 h and then ground. The ground beef was packaged and incubated at 4 degrees C for 21 days or 12 degrees C for 3 days. AA-treated samples held at 12 degrees C for 3 days yielded significantly lower aerobic plate counts than the control and also yielded the lowest levels of pseudomonads when compared to other sample groups. After being held at 4 degrees C for 21 days or 12 degrees C for 3 days, samples treated with antimicrobial compounds had lower or no detectable (< 1 CFU/g) levels of E. coli O157:H7, L. innocua, S. typhimurium, and C. sporogenes than beef treated with a WW or the control. Ground beef produced from tissue treated with HW yielded lower populations of these bacteria when compared to WW or untreated control beef, but the populations were generally higher than those observed in any of the antimicrobial chemical-treated samples. These trends continued throughout all storage conditions over time. Results from this study indicate that the use of carcass interventions, especially antimicrobial compounds, presently available to the slaughter industry will lower bacterial counts in ground beef.
测定了几种牛胴体表面组织（BCT）清洗干预措施对由此组织生产的碎牛肉微生物学的长期效果。将含有两种不同水平（约4或6 log CFU/ml）的大肠杆菌O157:H7、无害李斯特菌、鼠伤寒沙门氏菌和产芽孢梭菌之一的牛粪接种到BCT上。然后对BCT进行几种处理清洗之一：2%（体积/体积）DL-乳酸（LA）、2%（体积/体积）乙酸（AA）、12%（重量/体积）磷酸三钠（TSP）、热水（HW；组织表面温度为74±2℃）或水（WW；组织表面温度为32±2℃）。设立一个对照组不进行处理。处理后，将BCT在4℃下保存24小时，然后进行研磨。将碎牛肉包装好，在4℃下培养21天或在12℃下培养3天。在12℃下培养3天的经AA处理的样品，其好氧平板计数显著低于对照组，与其他样品组相比，其假单胞菌水平也最低。在4℃下保存21天或在12℃下保存3天后，与用WW处理或对照组处理的牛肉相比，用抗菌化合物处理的样品中大肠杆菌O157:H7、无害李斯特菌、鼠伤寒沙门氏菌和产芽孢梭菌的水平更低或检测不到（<1 CFU/g）。与用WW处理或未处理的对照牛肉相比，用HW处理的组织生产的碎牛肉中这些细菌的数量较少，但总体上高于在任何抗菌化学处理样品中观察到的数量。随着时间的推移，这些趋势在所有储存条件下都持续存在。本研究结果表明，屠宰行业目前可用的胴体干预措施，尤其是抗菌化合物，将降低碎牛肉中的细菌数量。
