ASSESSMENT OF THE HYGIENIC PERFORMANCES OF HAMBURGER PATTY PRODUCTIONPROCESSES

The hygienic conditions of the hamburger patties collected from three patty manufacturing plants and six retail outlets were examined. At ea ch manufacturing plant a sample from newly formed, chilled patties and one from frozen patties were collected from each of 25 batches of pat ties selected at random. At three, two or one retail outlet, respectiv ely, 25 samples from frozen, chilled or both frozen and chilled pattie s were collected at random. Each sample consisted of 30 g of meat obta ined from five or six patties. Total aerobic, coliform and Escherichia coli counts per gram were enumerated for each sample. The mean log (( x) over bar) and standard deviation (s) were calculated for the log(10 ) values for each set of 25 counts, on the assumption that the distrib ution of counts approximated the log normal. A value for the log(10) o f the arithmetic mean (log A) was calculated for each set from the val ues of (x) over bar and s. A chi(2) statistic was calculated for each set as a test of the assumption of the log normal distribution. The ch i(2) statistic was calculable for 32 of the 39 sets. Four of the sets gave chi(2) values indicative of gross deviation from log normality. O n inspection of those sets, distributions obviously differing from the log normal were apparent in two. Log A values for total, coliform and E. coli counts for chilled patties from manufacturing plants ranged f rom 4.4 to 5.1, 1.7 to 2.3 and 0.9 to 1.5, respectively. Log A values for frozen patties from manufacturing plants were between <0.1 and 0.5 log(10) units less than the equivalent values for chilled patties. Lo g A values for total, coliform and E. coli counts for frozen patties o n retail sale ranged from 3.8 to 8.5, <0.5 to 3.6 and <0 to 1.9, respe ctively. The equivalent ranges for chilled parries on retail sale were 4.8 to 8.5, 1.8 to 3.7 and 1.4 to 2.7, respectively. The findings ind icate that the general hygienic condition of hamburgers patties could be improved by their being manufactured from only manufacturing beef o f superior hygienic quality, and by the better management of chilled p atties at retail outlets. (C) 1997 Elsevier Science B.V.