REMOVAL OF SALMONELLA-TYPHIMURIUM ATTACHED TO CHICKEN SKIN BY RINSING WITH TRISODIUM PHOSPHATE SOLUTION - SCANNING ELECTRON-MICROSCOPIC EXAMINATION

The effect of trisodium phosphate (TSP) on Salmonella typhimurium attached to chicken skin was investigated by using scanning electron microscopy (SEM). Chicken drumsticks were inoculated with Salmonella typhimurium (2 x 10(8) CFU/mL) for 30 min. Both inoculated and non-inoculated drumsticks were rinsed with 10% TSP solution at 10 or 50C for 15 s, and skin pieces were cut and fixed for SEM examination. For inoculated skins, a significant difference was noticed between TSP-rinsed and control skins (water-rinsed) at both temperatures. While control skins were covered with salmonellae (4 x 10(5) similar to 1 x 10(6) CFU/cm(2)) and miscellaneous debris, TSP-rinsed skins, either at 10 or 50C, showed clean skin surfaces (<8 x 10(3) CFU/cm(2)). For non-inoculated skins, it was difficult to see the difference in the number of attached bacteria due to their low numbers, however, water-rinsed skins still showed the debris on the surface. Above observations suggest that one of the major mechanisms of rsp on salmonellae reduction is detachment of contaminants from the skin surface.