. 2017 Nov;95(11):5124–5136. doi: 10.2527/jas2017.1464

Table 8.

The effects of retail display day on the instrument color values (L*, a*, b*, hue angle, and saturation), discoloration ratio, and relative pigment proportions (% deoxymyoglobin and metmyoglobin) of overwrapped packaged longissimus lumborum steaks from cattle fed steam-flaked corn–based diets with ByPro¹ (tannic acid) fed at 0, 30, or 60 g/steer daily

	Retail display day
Variable	0	1	2	3	4	5	6	7	SEM²	P-value³
Instrument color
L*	41.47	43.06	41.14	38.71	39.60	39.68	45.72	35.64	2.99	0.18
a*	36.62^a	30.50^b	29.22^bc	28.90^c	25.20^d	22.89^e	19.63^f	20.80^f	2.73	<0.01
b*	30.20^a	24.28^b	24.43^b	24.86^b	21.98^c	20.80^d	18.62^e	20.77^d	2.22	<0.01
Hue angle⁴	39.36^de	38.43^e	39.99^d	40.78^cd	41.55^c	42.88^b	43.54^b	45.35^a	0.71	<0.01
Saturation⁵	47.50^a	39.00^b	38.12^b	38.13^b	33.49^c	30.98^d	26.42^e	29.58^d	3.38	<0.01
Pigment proportion⁶
Discoloration ratio	29.06^a	6.50^b	6.06^b	6.87^b	4.60^b	3.80^b	2.87^b	0.80^b	6.44	<0.01
Metmyoglobin	4.81^f	13.00^e	15.79^e	16.13^e	23.85^d	29.37^c	34.82^b	40.61^a	4.96	<0.01
Deoxymyoglobin	34.00^a	20.87^b	20.00^b	17.18^c	13.81^d	10.59^e	8.54^f	7.77^f	2.41	<0.01

^a–fLeast squares means in a row with different superscripts differ (P < 0.05).

Silvateam USA, Ontario, CA.

n = 10.

P-value for the effect of retail display day.

⁴

Hue angle = tan−1 b*/a*.

⁵

Saturation index = (a*2 + b*2)1/2.

⁶

Relative pigment proportions (%; metmyoglobin and deoxymyoglobin) were calculated using reflectance values obtained using a portable spectrophotometer (Hunter Miniscan XEPlus, model MSXP-4500C; Hunter Associates Laboratory, Inc., Reston, VA) and formulas outlined by the American Meat Science Association (2012).