title: Maintenance of safety and quality of refrigerated ready-to-cook seasoned ground beef product (meatball) by combining gamma irradiation with modified atmosphere packaging.
abstract: Meatballs were prepared by mixing ground beef and spices and inoculated with E. coli O157:H7, L. monocytogenes, and S. enteritidis before packaged in modified atmosphere (3% O₂ + 50% CO₂ + 47% N₂) or aerobic conditions. The packaged samples were irradiated at 0.75, 1.5, and 3 kGy doses and stored at 4 °C for 21 d. Survival of the pathogens, total plate count, lipid oxidation, color change, and sensory quality were analyzed during storage. Irradiation at 3 kGy inactivated all the inoculated (approximately 10⁶ CFU/g) S. enteritidis and L. monocytogenes cells in the samples. The inoculated (approximately 10⁶ CFU/g) E. coli O157:H7 cells were totally inactivated by 1.5 kGy irradiation. D¹⁰-values for E. coli O157:H7, S. enteritidis, and L. monocytogenes were 0.24, 0.43, and 0.41 kGy in MAP and 0.22, 0.39, and 0.39 kGy in aerobic packages, respectively. Irradiation at 1.5 and 3 kGy resulted in 0.13 and 0.36 mg MDA/kg increase in 2-thiobarbituric acid-reactive substances (TBARS) reaching 1.02 and 1.49 MDA/kg, respectively, on day 1. Irradiation also caused significant loss of color and sensory quality in aerobic packages. However, MAP effectively inhibited the irradiation-induced quality degradations during 21-d storage. Thus, combining irradiation (3 kGy) and MAP (3% O₂ + 50% CO₂ + 47% N₂) controlled the safety risk due to the potential pathogens and maintained qualities of meatballs during 21-d refrigerated storage.
  
  
  CONCLUSIONS
  Combined use of gamma irradiation and modified atmosphere packaging (MAP) can maintain quality and safety of seasoned ground beef (meatball). Seasoned ground beef can be irradiated at 3 kGy and packaged in MAP with 3% O₂ + 50% CO₂ + 47% N₂ gas mixture in a high barrier packaging materials. These treatments can significantly decrease risk due to potential pathogens including E. coli O157:H7, L. monocytogenes, and S. enteritidis in the product. The MAP would reduce the undesirable effects of irradiation on quality, and extend the shelf life of the product for up to 21 d at 3 °C.
authors.affiliation: Food Engineering Dept., Istanbul Technical Univ., Maslak, Istanbul, Turkey. gunesg@itu.edu.tr
authors.forename: Gurbuz
authors.initials: G
authors.lastname: Gunes
authors.forename: Aylin
authors.initials: A
authors.lastname: Ozturk
authors.forename: Neriman
authors.initials: N
authors.lastname: Yilmaz
authors.forename: Beraat
authors.initials: B
authors.lastname: Ozcelik
mesh_terms: D000818:Animals; D002245:Carbon Dioxide / Q000009:adverse effects / Q000032:analysis / Q000378:metabolism; D002417:Cattle; D015169:Colony Count, Microbial; D019453:Escherichia coli O157 / Q000254:growth & development* / Q000302:isolation & purification / Q000378:metabolism / Q000528:radiation effects; D005514:Food Irradiation / Q000009:adverse effects; D018857:Food Packaging; D005517:Foodborne Diseases / Q000517:prevention & control; D005720:Gamma Rays / Q000009:adverse effects; D006801:Humans; D015227:Lipid Peroxidation / Q000528:radiation effects; D008089:Listeria monocytogenes / Q000254:growth & development* / Q000378:metabolism / Q000528:radiation effects; D008461:Meat Products / Q000032:analysis* / Q000382:microbiology*; D050296:Microbial Viability / Q000528:radiation effects; D010100:Oxygen / Q000009:adverse effects / Q000032:analysis / Q000378:metabolism; D010858:Pigmentation / Q000528:radiation effects; D012034:Refrigeration; D012477:Salmonella enteritidis / Q000254:growth & development* / Q000378:metabolism / Q000528:radiation effects; D012677:Sensation; D017365:Spices
chemical_list: D002245:Carbon Dioxide; D010100:Oxygen