Submitted to: Journal of Animal Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: May 20, 1999
Publication Date: N/A
Interpretive Summary: The effectiveness of irradiation for eliminating pathogenic bacteria in food is well established. Because the Food and Drug Administration approved ionizing radiation for refrigerated and frozen uncooked meat, the meat industries now are considering whether they should utilize this technology to improve the safety of their products and, if so, how they should apply it. The objectives of this experiment were to determine 1) the effect of two levels of low dose irradiation on trained sensory panel evaluation of vacuum- packaged frozen ground beef patties using commercially produced product, and 2) to determine consumer perception of the taste of hamburgers made from those patties. Boxes of frozen quarter-pound ground beef patties from a commercial supplier were irradiated at a commercial irradiation facility. The trained sensory panel detected detrimental changes in flavor and odor in patties from both irradiation doses compared to the control. However, these changes caused minimal effects on consumer taste ratings at an irradiation dose (3.0 deg kGy) necessary to provide a 5 D kill (99.999%) of E. coli 0157:H7 in 19% fat, vacuum-packaged, frozen ground beef patties and only slightly greater effects on consumer taste ratings at an irradiation dose (4.5 kGy) necessary to provide a 5 D kill of Salmonella spp. These results imply that the detrimental changes in sensory traits of ground beef patties irradiated under the conditions of this experiment would cause few, if any, consumer acceptance problems at the 3.0 kGy dose and only slightly greater problems at the 4.5 kGy dose, when consumed as part of a hamburger.
Technical Abstract: The objectives of this experiment were to determine the effect of gamma irradiation on 1) the palatability of vacuum-packaged frozen ground beef patties by trained sensory panel and 2) consumer evaluation (n = 110) of the taste of hamburgers made with those patties. Boxes (4.5 kg) of frozen (-28 deg C) ground beef patties (113.4 g/patty, 19% fat) from a commercial supplier were irradiated at a commercial gamma irradiation facility at one of three levels (0, 3.0, or 4.5 kGy). The trained panel evaluated grilled patties and found that control patties had more intense (P < .05) ground beef aroma (3.1 vs 2.6), less off- aroma (3.3 vs 2.6), and more intense ground beef flavor (4.9 vs 4.3) than irradiated patties. However, there were no differences (P > .05) in any sensory trait between frozen ground beef patties treated with 3.0 or 4.5 kGy of gamma irradiation. The consumers evaluated taste of a hamburger that included their choice of condiments on a 10-point scale (10 = excellent; 1 = terrible). Hamburgers made with patties treated with 4.5 kGy were rated lower (P < .05) in taste than hamburgers made with either control or 3.0 kGy treated patties (6.5, 6.6, and 6.2, respectively for 0, 3.0, and 4.5 deg kGy), however, all doses were rated at some level of "fair." These results imply that the detrimental changes in sensory traits of hamburgers made from ground beef patties irradiated under the conditions of this experiment would cause few, if any, consumer acceptance problems at the 3.0 kGy dose and only slightly greater problems at the 4.5 kGy dose, when consumed as part of a hamburger.