THE HYGIENIC CONDITION OF MANUFACTURING BEEF DESTINED FOR THE MANUFACTURE OF HAMBURGER PATTIES

The hygienic condition of the manufacturing beef collected at six carc ass breaking plants for dispatch to hamburger patty manufacturing plan ts was examined. At each plant, 24 x 1 kg samples of meat were selecte d at random from the product being collected into bulk containers. Tot al aerobic, coliform and Escherichia cell counts per gram were enumera ted for each sample. The log mean ((X) over bar) and standard deviatio n (s.d.) were calculated for the log(10) values of each set of 24 coun ts, on the assumption that the distribution of counts approximated the log normal. A value for the log(10) of the arithmetic mean (log A) wa s calculated for each set from the values for X and s.d. Log A values for total, coliform and E. coil counts ranged from 3.5 to 4.9, 0.7 to 3.0 and 0.2 to 2.6 log(10) cfu g(-1), respectively. For each set of sa mples, there was a weak or no correlation between log,, values for tot al counts and those for coliforms or E. coil, but correlations between log(10) values for coliform and E. coli counts ranged from non (R(2)= 0.19) to close (R(2)=0.97). The results show that there are large diff erences between plants in the numbers of E. coli in the manufacturing beef which they produce. The differences in E. coli numbers are not re liably reflected by differences between total or coliform counts in pr oduct from different plants. In addition, the findings indicate that m anufacturing beef obtained from culled cow carcasses may generally be less heavily contaminated with E. coli than the trimmings obtained fro m the carcasses of feedlotted steers. Clearly, some current processes for the production of manufacturing beef destined for hamburger patty manufacture are poorly controlled with respect to minimizing the conta mination of product with E. coli and, presumably, other faecal bacteri a. The methods used in this study offer a means of objectively identif ying such hygienically inadequate processes. (C) 1996 Academic Press L imited