Factors affecting the use of chlorine in the spin‐chilling of eviscerated poultry

Abstract

Conditions have been determined under which chlorination can be used to eliminate both faecal and spoilage bacteria from the water used for chilling eviscerated poultry carcasses, thus avoiding any hazard from cross‐contamination. All combinations of three rates of water usage (2.5, 5 or 8 1 per carcass) and three concentrations of total residual chlorine (10 to 15, 25 to 30 or 45 to 50 ppm), obtained by the addition of sodium hypochlorite, were compared. It was found that the majority of bacteria present were destroyed by the use of 45 to 50 ppm of total chlorine in conjunction with 5 1 of water per carcass. When the rate of water usage was increased to 8 1 per carcass it was found that 25 to 30 ppm of residual chlorine in the chill‐water gave comparable results. The effect of water usage on the concentrations of free residual chlorine present in the chill‐water during processing is discussed. When chlorine gas was added continuously at a fixed concentration to the input water the concentration of total residual chlorine decreased in each chiller. This method of chlorination was found to be less effective in destroying bacteria than the hypochlorite method which could be used to vary the amount of added chlorine in order to maintain the required total residual concentration during processing.