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Microbial Quality and Safety of X‐Ray Irradiated Fresh Catfish ( Ictalurus punctatus ) Fillets Stored under CO 2 Atmosphere
Author(s) -
Gawborisut S.,
Kim T.J.,
Sovann S.,
Silva J.L.
Publication year - 2012
Publication title -
journal of food science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.772
H-Index - 150
eISSN - 1750-3841
pISSN - 0022-1147
DOI - 10.1111/j.1750-3841.2012.02866.x
Subject(s) - food spoilage , food science , psychrotrophic bacteria , lactic acid , catfish , shelf life , bacteria , chemistry , aerobic bacteria , modified atmosphere , listeria monocytogenes , food preservation , anaerobic bacteria , food irradiation , irradiation , biology , fish <actinopterygii> , fishery , genetics , physics , nuclear physics
The effect of low‐dose X‐ray irradiation (0, 2, and 3 kGy) on pathogens, spoilage bacteria (psychrotrophic, anaerobic, and lactic acid bacteria), and physicochemical parameters of iced catfish fillets stored under carbon dioxide (CO 2 ) atmosphere were studied. Irradiation of 2 or 3 kGy eliminated all Listeria monocytogenes (4.8 log CFU/g) and Salmonella Typhimurium (4.7 log CFU/g) while CO 2 atmosphere alone showed less than 1 log reduction on Salmonella Typhimurium. There was no recovery of either pathogen for the experimental period. Regardless of dose, irradiation showed 2 log reduction on psychrotrophic, anaerobic, and lactic acid bacteria for 24 d. Further post‐irradiation reductions of spoilage bacteria were observed. Spoilage bacteria on catfish fillets treated with 2 kGy irradiation regained their growth after 16 d of storage. However, catfish fillets exposed to 3 kGy did not show growth of spoilage bacteria throughout the experimental period (24 d). Irradiation (2 or 3 kGy) increased pH and TBARS, and decreased Hunter “b” values but produced no effect on water holding capacity and texture. Shelf life of catfish fillets exposed to 2 or 3 kGy irradiation could be extended by more than 24 d at 2 to 4 °C, with the added safety of possibly eliminating pathogens.