Table 4. Free amino acid content for sample groups determined by PI and TBARS

Free amino acid (mg/100 g dry-cured loin)	HH	HL	LH	LL	SEM	p-value
Taurine	105.45	103.70	87.96	89.94	5.89	ns
Aspartic	62.63^a	42.11^c	51.20^b	42.73^c	3.28	^***
Threonine	130.14^a	99.53^c	102.69^b	95.00^c	4.84	^***
Serine	77.63^a	59.16^b	61.28^b	55.62^c	2.76	^***
Asparagine	87.54^a	67.37^b	69.55^b	62.26^c	2.95	^***
Glutamic	248.69^a	200.99^b	198.03^b	189.92^c	7.96	^***
Proline	71.22	63.36	60.74	69.51	5.49	ns
Glycine	118.05^a	94.95^b	94.42^b	86.23^c	4.20	^***
Alanin	214.74^a	164.56^c	173.92^bc	167.88^c	6.74	^***
Valine	132.67^a	105.96^c	114.05^b	109.50^c	4.98	^**
Methionine	72.91^a	61.71^b	59.43^c	54.71^d	1.93	^***
Isoleucine	104.36^a	85.84^bc	89.01^b	84.76^c	3.34	^***
Leucine	175.04^a	143.35^b	145.22^b	135.52^c	5.46	^***
Tyrosine	103.78^a	85.95^b	86.51^b	81.75^c	2.87	^***
Phenylalanine	87.37^a	75.42^b	73.90^b	68.82^c	2.23	^***
Ornithine	5.29^b	4.06^b	7.74^a	6.29^a	0.72	^**
Lysine	246.63^a	204.34^b	209.20^b	200.70^b	8.55	^***
Histidine	60.24^a	53.74^b	49.76^c	48.47^c	2.31	^**
Tryptophan	16.18^a	8.82^b	6.57^c	3.27^d	1.65	^***
Anserine	33.21	32.47	31.04	31.50	0.82	ns
Arginine	152.19^a	122.13^b	122.33^b	114.75^c	4.72	^***
Total	2,309.72^a	1,880.55^b	1,895.55^b	1,799.26^c	78.51	^***

Different small letters within different sample groups were significantly different (p<0.05).
p<0.05;
p<0.01;
p<0.001.
PI, proteolytic index; TBARS, 2-thiobarbituric acid reactive substances; HH, PI and TBARS of high levels; HL, PI of high level and TBARS of low level; LH, PI of low level and TBARS of high level; LL, PI and TBARS of low levels; ns, no significance.