EFFECTS OF IONIZING-RADIATION AND ANAEROBIC REFRIGERATED STORAGE ON INDIGENOUS MICROFLORA, SALMONELLA, AND CLOSTRIDIUM-BOTULINUM TYPE-A ANDTYPE-B IN VACUUM-CANNED, MECHANICALLY DEBONED CHICKEN MEAT

Vacuum-canned, commercial, mechanically deboned chicken meat was chall enged with either Clostridium botulinum spores (20 strains of types A and B, proteolytic; final spore concentration of ca. 400/g of meat) or Salmonella enteritidis (ca. 10(4) CFU/g of meat) followed by irradiat ion to 0, 1.5, and 3.0 kGy and storage at 5 degrees C for 0, 2, and 4 weeks. None of the samples stored at 5 degrees C developed botulinal t oxin; however, when these samples were temperature abused at 28 degree s C they became toxic within 18 h and had obvious signs of spoilage, i .e., swelling of the can and a putrid odor. During 4 weeks of refriger ated storage the log(10) of the population of S. enteritidis in nonirr adiated samples decreased from 3.86 to 2.58. S. enteritidis CFU were d etectable in samples irradiated to 1.5 kGy at 0 weeks but not in sampl es irradiated to 3.0 kGy. Log levels of aerobic and facultative mesoph iles increased during 4 weeks of refrigerated storage from 6.54 to 8.2 5, 4.03 to 8.14, and 2.84 to 5.23 in samples irradiated to 0, 1.5, and 3.0 kGy, respectively. Based on taxonomic analyses of 245 isolates, t he bacterial populations depended upon radiation dose and storage time . The change was predominantly from gram-negative rods in nonirradiate d samples to gram-positive streptococci in samples irradiated to 3.0 k Gy and stored for 4 weeks. Spoilage organisms survived even the 3.0 kG y treatment.