The microbiology of polony

A survey of 25 polony samples of different brands available to the consumer in Bloemfontein showed that significant numbers of various micro-organisms were present. Aerobic micro-organisms, psychrophiles, micrococci, pseudomonads, Microbacterium thermosphactum, lactobacilli, yeasts and moulds were enumerated by the plate count technique. The mean aerobic plate count was 15,850/g and counts ranged between less than 100/g and greater than 1 million/g. Selective plate counts indicated that psychrophiles, pseudomonads and lactobacilli were the main groups present. During storage at 5 degrees C for 12 d, the mean pH of polony declined from 6,32 to 6,20 while the aerobic count increased 13 fold. Counts of all groups increased during storage at 5 degrees C especially M. thermosphactum, yeasts and moulds. No salmonellae were found and counts of Escherichia coli or Staphylococcus aureus were less than 3/g. Storage of 5 polony samples at 1.1 degrees +/- 1 degrees C until they spoilt after 8 wks resulted in the aerobic count increasing to greater than 10(8)/g. Lactobacilli and psychrophiles increased most rapidly while pH decreased from 6,20 to 5,57. Organisms isolated most frequently from spoilt polony were yeasts, micrococci, lactic acid bacteria and corynebacteria. It is concluded that standards for microbiological quality of polony are unnecessary.