Table 1. Least square means of physicochemical and quality traits of m. longissimus lumborum and biceps femoris muscles as affected by aging and electrical stimulation

Traits	Muscle	Aging 2 d		Aging 14 d		SEM	F-value
		Control	ES	Control	ES		Aging	ES	Muscle
pH	LL	5.46	5.46	5.54	5.51	0.02	15.9**	0.7	0.7
	BF	5.48	5.49	5.52	5.52	0.01	9.1*	0.1
WBSF (kg)	LL	3.61	2.82	2.47	2.01	0.17	31.7***	12.9**	37.3***
	BF	4.64	3.60	3.63	3.23	0.23	8.5*	9.3*
Total collagen (g/100 g)	LL	0.26	0.24	0.31	0.23	0.02	0.66	2.4	96.8***
	BF	0.42	0.43	0.48	0.49	0.03	3.36	0.1
Soluble collagen (g/100 g)	LL	0.09	0.07	0.11	0.08	0.02	0.76	0.01	28.4***
	BF	0.18	0.13	0.16	0.22	0.03	1.44	3.1
Cooking loss (%)	LL	16.5	17.5	16.4	17.2	0.55	0.11	2.4	14.3**
	BF	20.0	19.2	17.9	18.2	0.87	3.17	0.1
CIE L*	LL	39.7	41.6	41.4	42.2	1.21	1.01	1.4	6.5*
	BF	38.9	38.3	40.2	40.4	0.86	3.92	0.1
CIE a*	LL	18.2	19.4	19.9	18.9	0.61	0.86	0.02	1.1
	BF	19.2	18.6	20.0	20.1	0.54	4.35*	0.2
CIE b*	LL	14.5	15.9	16.3	15.8	0.58	2.01	0.6	5.2*
	BF	14.3	13.7	15.5	15.2	0.55	6.02*	0.7
Intramuscular fat (%)	LL	26.3				2.12			32.6***
	BF	7.8				1.04
Moisture (%)	LL	59.0				1.21			44.5***
	BF	68.4				0.72
TBARS (mg MDA/kg)	LL	0.21	0.23	0.33	0.33	0.03	12.31**	0.2	0.5
	BF	0.23	0.24	0.31	0.27	0.02	5.86*	0.4

p<0.05
p<0.01
p<0.001.
ES, electrical stimulation; LL, m. longissimus lumborum; BF, m. biceps femoris; WBSF, Warner-Bratzler shear force; TBARS, thiobarbituric acid reactive substances.