A triangle test (difference analysis) was performed to detect possible difference in the overall sensory quality of hard-boiled fresh egg yolk from diet 1, 2, and 5 and store-bought (SB) eggs (Sparboe white eggs from conventional production) from a local grocery store in Ames, IA, U.S.A. The eggs were put in boiling water and boiled for 10 min, removed and naturally cooled at ambient temperature for 1 h, and then stored in refrigerator (4 ˚C)for 1 d before the sensory test. Whole eggs were cut into halves and the halves were served to the panelists at ambient temperature. Limited by the number of triangles that one taster can evaluate at a time, 4 sets of triangles were designed: SB against diet 1, diet 1 against diet 2, diet 1 against diet 5, and diet 2 against diet 5. We hypothesized that there would not be any detectable difference among all treatments, so we included the eggs with the lowest and highest enrichment levels. Sixty-eight untrained tasters, including
31 females, 33 males, and 4 unidentified, were recruited with an average age of 25. Each taster was served with 3 randomly chosen triangles at a time, and was asked to evaluate the yolk and identify an odd sample out of the 3 in 1 triangle. The difference in each pair of treatments was examined by comparing the actual number of correct answers with the number necessary to establish 5%