Microbiological aspects of polyphosphate injection in the processing and chill storage of poultry.

During commercial processing of broiler chickens, injection of polyphosphate (Puron 604 or 6040) resulted in microorganisms being added to the deep breast muscle. The level of contamination was related to the microbiological condition of the injection solution. Injection of polyphosphate had no effect on the shelf-life of fresh chilled carcasses held at 1 degree of 10 degrees C but changes were observed in the growth rate of microorganisms in the deep muscle and in the composition of the muscle microflora following storage. Cross-contamination of carcasses and the transfer of organisms from the skin to the deep muscle during injection was demonstrated with a marker strain of Clostridium perfringens. However, both processes were influenced by the number of marker organisms applied initially to the skin. The above findings are discussed in relation to the possible behaviour of any food poisoning bacteria present.