Trained sensory panel and consumer evaluation of the effects of gamma irradiation on palatability of vacuum-packaged frozen ground beef patties

The objectives for this experiment were to determine the effects of gamma i rradiation on 1) the palatability of vacuum-packaged frozen ground beef pat ties by trained sensory panel and 2) consumer evaluation of the taste of ha mburgers made with those patties. Boxes (4.5 kg) of frozen (-28 degrees C) ground beef patties (113.4 g/patty, 19% fat) from a commercial supplier wer e irradiated at a commercial gamma irradiation facility at one of three lev els (0, 3.0, or 4.5 kGy). All boxes were stored at 28 degrees C for 27 to 2 9 d after irradiation before evaluation by a trained descriptive attribute sensory panel and for 62 to 104 d after irradiation before consumer evaluat ion. The trained panel evaluated grilled patties for ground beef aroma inte nsity, off-aroma, and off-flavor on 4-point scales (4 = intense, none, and none; 1 = none, intense, and intense, respectively) and ground beef flavor intensity, tenderness, and juiciness on 8-point scales (8 = extremely inten se, tender, or juicy; 1 = extremely bland, tough, or dry). 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 irradiat ed patties. However, there were no differences (P > .05) in any sensory tra it between frozen ground beef patties treated with 3.0 or 4.5 kGy of gamma irradiation. There were no differences (P > .05) among treatments for tende rness (6.3, 6.6, and 6.7) or juiciness ratings (5.7, 5.9, and 5.9), respect ively, for 0, 3.0, and 4.5 kGy. The consumers evaluated taste of a hamburge r that included their choice of condiments on a 10-point scale (10 = excell ent; 1 = terrible). Hamburgers made with patties treated with 4.5 kGy were rated lower (P < .05) in taste than hamburgers made with either control pat ties or those treated with 3.0 kGy (6.5, 6.6, and 6.2, respectively, for 0, 3.0, and 4.5 kGy); however, all doses were rated at some level of "fair." These results imply that hamburgers made from ground beef patties irradiate d under the conditions of this experiment would encounter little, if any, c onsumer acceptance problems at the 3.0 kGy dose and only slightly greater p roblems at the 4.5 kGy dose.