Alteration of scalding fluids and drips from other processing STEPS BY time in poultry slaughterhouse and their effects on microbiological quality of carcasses

Scalding is carried out at static water using either clean (A; replaced with clean water) ordirty (B; with no change during the entire shift) water in small or medium-size broiler slaughterhouses. The objective of this study was to investigate the effect of the condition of scalding water on microbiological and chemical parameters of the scalding waters by time, on the microbiological quality of the chilled carcassees, and the relationship between these parameters. For this purpose, on each of the days when clean or dirty water was used for scalding, samples were collected in every 30 minfor 180 min from each of 3 scalding tanks (Tank 1, Tank 2, Tank 3), from drips collected after defeathering and inner-outer bird washing steps, and from chilled carcasses. All samples were analyzed for the numbers of E. coli biotype I, coliform, total mesophilic aerobic bacterial count, Salmonella spp., and psychrotrophic bacterial count. Also scalding tank samples were analyzed for the level of organic matter, total dry matter, pH and protein levels. There was no significant difference in total mesophilic aerobic bacterial count by time in either A and B groups in after defeathering, inner-outer washing and chilled carcasses samples. However, the total mesophilic aerobic bacterial counts of the same sampling points in the A and B groups were compared by time, significant differences (p<0.05) were detected. There was no significant difference in psychrotrophic bacterial count between groups or sampling intervals (p>0.05). Salmonella spp. prevalences in groups A and B %63 and %75 respectively. Numbers of E. coli and coliform bacteria did not show a significant difference by time in group B. Numbers of E. coli and coliform bacteria the only significant difference found between A and B groups were at 0 min while no differences were detected at there maining sampling intervals. There was no significant difference chemical parameters in group B, appreciable increases in organic matters and dry substance levels in group A (p<0.05). In addition, a moderate positive correlation was found between the organic substance level in the scalding tanks and the numbers of coliform bacteria of the carcasses. As a result, effect of scalding with clean water on microbiological quality of the broiler carcasses disappeared within the first 30 min, and no meaningful difference was found during the remaining time period. Regardless of the condition of the scalding water, defeathering step played the most important role in contamination of the carcasses. In addition, correlation between the level of organic substance in the scalding water and coliform bacteria may indicate that this parameter can have a potential to be used as critical limit in plants using clean water-scalding.