Effect of low-dose irradiation (radurization) on the shelf life of beefburgers stored at 3oC

The bacteriological, chemical (FFA and peroxide value) and organoleptic quality of stored (3°C) radurized beefburgers were investigated. Treatment with gamma radiation at doses of 0.103 and 0.154 Mrad (1.03 and 1.54 kGy) resulted in an immediate reduction in total bacterial numbers of 82 and 92%, respectively. No ‘pseudomonadlike’ organism survived irradiation. Beefburger surface colour was influenced more than internal colour by irradiation; the larger dose (154 krad, 1.54 kGy) having the more pronounced effect. At the end of 15 days storage (3°C) ‘spoilage’ odours were not detected in the 1.54 kGy treated burgers but were detected in those irradiated at 103 krad (1.03 kGy). However ‘irradiation’ odours were detectable at both levels of treatment when burgers were exposed to the air. Irradiation had a larger effect on peroxide formation than on free fatty acid formation.