Table 1.

Lean quality estimates of the ventral surface boneless pork loins from pigs selected for lean growth or meat quality traits and categorized based on proposed USDA grade standards of pork carcasses

Item	Production focus		SEM	USDA quality gradea			SEM	P-values
	Lean	Quality		Standard	Select	Choice		Production focus	USDA quality grade	Focus × quality grade
Loins, n	78	73		38	13	92
Loin weight, kg	5.40	5.03	1.07	5.40b	5.19ab	5.07a	1.08	< 0.01	0.01	0.44
Ventral pH	5.69	5.72	0.05	5.72ab	5.65a	5.75b	0.06	0.20	0.02	0.95
Lightnessb, L*	43.80	45.23	0.51	44.20b	46.14c	43.21a	0.80	0.01	<0.01	0.41
Rednessb, a*	7.36	7.83	0.20	7.16a	7.83b	7.79b	0.32	0.05	0.01	0.62
Yellownessb, b*	0.46	0.87	0.20	0.41	0.95	0.64	0.29	0.04	0.15	0.15
Colorc	3.08	3.16	0.15	3.27b	2.49a	3.60c	0.20	0.55	<0.0001	0.69
Extractable lipid, %	2.12	2.51	0.23	1.61a	2.77b	2.56b	0.30	0.04	<0.0001	0.78
Marblingc	1.95	2.03	0.07	1.28a	2.27b	2.42b	0.11	0.39	<0.0001	0.73
Firmnessc	2.62	2.76	0.28	2.46a	2.66ab	2.95b	0.32	0.34	<0.01	0.63

^aUSDA quality grades are based on the newly proposed grade standards for pork carcasses where: Choice = NPPC color score of 3 and a NPPC marbling score ≥ 2, Select = NPPC color score of 2 and a NPPC marbling score ≥ 2, Standard either has a NPPC color and a NPPC marbling score ≥ 2, Select = NPPC color score of 2 and a NPPC marbling score ≥ 2, Standard either has a NPPC color score < 2 or a NPPC marbling score < 2.

^bL* = measure of lightness (greater value indicates a lighter color), a* = measure of redness (greater value indicates a redder color), and b* = measure of yellowness (greater value indicates a more yellow color).

^cNPPC color (1 = pale pink to 6 = dark purplish red), NPPC marbling (1 = 1% intramuscular lipid to 10 = ≥10% intramuscular lipid), and NPPC firmness (1 = very soft to 5 = very firm) were based on NPPC (1991, 1999) standards.