The Effect of Acetic Acid and Air Injection on Appearance, Moisture Pick-Up, Microbiological Quality, and Salmonella Incidence on Processed Poultry Carcasses

Abstract

Broiler carcasses were subjected to a 10-min prechill treatment with and without air injection and glacial acetic acid at concentrations of .3 and .6%. Some of the carcasses were inoculated with approximately 800 cells of a nalidixic acid-resistant strain of Salmonella typhimurium 1 min prior to treatment. After treatment, the carcasses were monitored for their visual appearance, moisture pick-up, and microbiological quality. Appearance was subjectively monitored for color change and resulting skin texture. Microbiological quality was determined using the low volume whole carcass rinse, and moisture pick-up was determined by weight differences. The skin color of treated carcasses was light yellow and the feather follicles were protruded or puckered. Moisture pick-up was significantly reduced by the acid treatments. Total aerobes were not affected by any of the treatments, but Enterobacteriaceae (ENT) counts of treated carcasses were significantly lower than the counts for the water control carcasses. Log10 ENT counts ranged from 5.52 for the control to 4.48 for the air injection, and to a low of 2.93 for the air injection with .6% acetic acid. Salmonella incidence of inoculated carcasses was significantly reduced by the treatments. Using .6% acetic acid with air injection resulted in the greatest reduction in Salmonella incidence (8% positive).