Studies of different sampling methods for the determination of bacterial counts from frozen broilers

Evaluation of alternative sampling methods for Salmonella critical control point determination at broiler processing

Several sampling methods have been developed for the detection of Salmonella on broiler carcasses during commercial processing. The present study evaluated three sampling methodologies for sensitivity of Salmonella detection on processed broiler carcasses. Furthermore, the effect of crop removal or chill tank exposure on the frequency of Salmonella recovery was also examined. In two experiments, swab, skin, and carcass rinse samples were compared for sensitivity of Salmonella detection. The results indicated that culture of swabs was less effective (P < 0.05) for Salmonella detection than either skin or carcass rinse samples. No significant (P > 0.05) differences were observed in Salmonella recovery from culture of skin or carcass rinse. In two subsequent experiments, skin and carcass rinse samples were found to be equally sensitive in their ability to detect Salmonella. Additionally, the stages of processing between feather and crop removal were observed to cause significant (P < 0.05) increases in Salmonella recovery within an individual flock. Similar increases (P < 0.05) in Salmonella recovery were also observed following crop removal and immediately following immersion chilling in two separate flocks. These results suggest that culture of skin samples obtained from the thoracic inlet region may be a viable alternative to the traditional whole carcass rinse method for sensitivity of Salmonella detection. Furthermore, these experiments provided some evidence that the majority of Salmonella cross-contamination of carcasses prior to immersion chilling occurred following evisceration, with the chill tank potentially providing a major site for cross-contamination between Salmonella-negative and-positive flocks.

The microbiology of raw, eviscerated chickens: a ten year comparison

In 1979 a survey of selected chicken eviscerating plants was conducted to determine the levels of coliforms, Escherichia coli, and Salmonellae sp. on eviscerated chickens under current manufacturing practices. A comparison was made of the data from this survey and one conducted in 1969. The 1979 survey found that the chickens did not have a statistically significant reduced incidence of salmonella compared to chickens analyzed in 1969. Also, much of the bacterial contamination on a carcass at the end of the evisceration line was transient and was readily removed by the final spray washer. The addition of chlorine to chiller water did not appear to have an unusually beneficial effect on the microbiological quality of the chickens. In 1969, in the nine plants studied, the incidence of salmonella on chickens at the exit of the chillers was 20.5%. In 1979, in the nine plants studied, the incidence of salmonella on chickens at the exit of the chillers was 11.6%. In 1979 there was about a 45% reduction in the incidence of salmonella in eviscerated chickens in the nine plants studied compared to the incidence of salmonella in eviscerated chickens in 1969.