Relationship between consumer ranking of lamb colour and objective measures of colour

Given the lack of data that relates consumer acceptance of lamb colour to instrument measures a study was undertaken to establish the acceptability thresholds for fresh and displayed meat. Consumers (n = 541) were asked to score 20 samples of lamb loin (m.longissimus thoracis et lumborum; LL) on an ordinal scale of 1 (very acceptable) to 5 (very unacceptable). A sample was considered acceptable by a consumer if it scored three or less. Ten samples were used for testing consumer response to fresh colour and 10 to test consumer response to colour during display of up to 4 days. The colour of fresh meat was measured using a Minolta chromameter with a closed cone and a Hunter Lab Miniscan was used for measuring meat on display. For fresh meat when the a∗ (redness) and L∗ (lightness) values are equal to or exceed 9.5 and 34, respectively, on average consumers will consider the meat colour acceptable. However a∗ and L∗ values must be much higher (14.5 and 44, respectively) to have 95% confidence that a randomly selected consumer will consider a sample acceptable. For aged meat, when the wavelength ratio (630/580 nm) and the a∗ values are equal to or greater than 3.3 and 14.8, respectively, on average consumers will consider the meat acceptable. These thresholds need to be increased to 6.8 for ratio (630/580 nm) and 21.7 for a∗ to be 95% confident that a randomly selected consumer will consider a sample acceptable.