Table 4.

Volatile aroma compounds (μg/g) of cooked pork longissimus dorsi muscle as affected by quality grade

Items	Retention time (min)	QG1+	QG1	QG2	Identification method1)
Aldehyde
Propanal	1.701	ND	0.05±0.00	0.07±0.01	MS+STD
Butanal	2.140	ND	0.02±0.01	0.03±0.02	MS+STD
2-methyl-heptanal	3.279	0.05±0.00	0.04±0.01	0.04±0.02	MS+STD
Hexanal	6.075	1.49±0.17a	0.43±0.06b	0.47±0.07ab	MS+STD
Heptanal	9.244	0.12±0.02	0.12±0.03	0.14±0.06	MS+STD
E-2-heptenal	10.737	ND	0.02±0.00	0.02±0.01	MS+STD
Benzaldehyde	10.851	0.61±0.01a	0.43±0.03b	0.45±0.05b	MS+STD
Octanal	11.904	0.22±0.03	0.18±0.05	0.23±0.08	MS+STD
E-2-octenal	13.168	0.03±0.00	0.04±0.01	0.04±0.01	MS+STD
E,E,2,4-decadienal	13.869	ND	0.01±0.00	0.03±0.01	MS+STD
Nonanal	14.179	0.68±0.11	0.43±0.09	0.51±0.17	MS+STD
E-2-nonenal	15.513	ND	0.02±0.01	0.02±0.01	MS+STD
Decanal	16.207	0.03±0.00	0.03±0.01	0.07±0.03	MS+STD
E-2-decenal	17.253	ND	0.02±0.01	0.08±0.04	MS+STD
Undecanal	18.065	ND	0.02±0.00	0.08±0.05	MS
2-undecenal	19.051	0.02±0.01	0.04±0.01	0.07±0.03	MS
Tridecanal	21.429	0.03±0.01	0.03±0.01	0.07±0.03	MS
Pentadecanal	22.966	ND	0.05±0.01	0.03±0.00	MS
Tetradecanal	25.836	ND	0.33±0.05	0.23±0.09	MS
Total aldehydes		2.94±0.21a	1.70±0.23b	2.17±0.34ab
Alcohols
1-pentanol	5.008	0.03±0.00	0.02±0.00	0.02±0.01	MS+STD
1-heptanol	11.079	0.03±0.01	0.05±0.01	0.05±0.02	MS+STD
1-octen-3-ol	11.326	0.13±0.01a	0.06±0.01b	0.06±0.01b	MS+STD
Benzyl alcohol	12.604	0.03±0.01	0.06±0.00	0.08±0.02	MS
Total alcohols		0.21±0.02a	0.11±0.02b	0.13±0.04b
Pyrazines
Methylpyrazine	6.890	0.06±0.01	0.05±0.01	0.04±0.00	MS+STD
2,5-dimethyl pyrazine	9.505	0.18±0.03	0.20±0.01	0.12±0.03	MS+STD
2,3-dimethylpyrazine	9.648	0.03±0.01	0.04±0.00	0.04±0.00	MS+STD
Trimethyl pyrazine	11.821	0.13±0.02	0.13±0.01	0.07±0.02	MS
3-methyl-2,5-dimethyl pyrazine	13.540	0.07±0.01	0.06±0.00	0.06±0.00	MS
Total pyrazines		0.45±0.07	0.47±0.02	0.23±0.09
Sulfur-containing compounds
Carbon disulfide	1.864	ND	0.00±0.00	0.06±0.01	MS
3-thiophene-carboxaldehyde	11.645	0.05±0.01	0.04±0.00	0.05±0.01	MS
2-thiophene methanol	12.512	ND	0.06±0.00	0.06±0.01	MS
Dimethyl tetrasulfide	16.495	0.03±0.02	0.03±0.01	0.02±0.00	MS
3-thiophene acetic acid	17.139	0.02±0.01ab	0.01±0.00b	0.05±0.02a	MS+STD
3-phenyl thiophene	19.822	0.87±0.11	0.41±0.18	1.22±0.55	MS+STD
2-phenyl thiophene	19.988	0.55±0.07	0.43±0.14	0.73±0.31	MS+STD
Total sulfur-containing compounds	1.51±0.20	0.74±0.30	2.08±0.86
Hydrocarbons
Ethylbenzene	7.966	0.03±0.00	0.02±0.00	0.02±0.00	MS
1,3-dimethylbenzene	8.245	0.13±0.01a	0.05±0.02b	0.08±0.02ab	MS
2,5-octanedione	11.461	0.13±0.02a	0.03±0.01b	0.04±0.01b	MS
3-methyl-butanamide	12.037	0.02±0.00	0.01±0.00	0.02±0.00	MS
Dodecane	16.081	0.05±0.01	0.03±0.01	0.04±0.01	MS
Tridecane	17.917	0.04±0.02	0.02±0.01	0.06±0.01	MS
Tetradecane	19.636	0.04±0.01a	0.02±0.00b	0.04±0.01a	MS
Total hydrocarbons		0.40±0.03a	0.15±0.04b	0.26±0.05b
Ketones
Acetophenone	13.344	0.03±0.01	0.03±0.01	0.03±0.01	MS
2-decanone	15.916	0.05±0.00b	0.02±0.01b	0.07±0.02a	MS+STD
2-tridecanone	21.168	ND	0.02±0.01	0.02±0.01	MS
Total ketones		0.09±0.01	0.05 0.01	0.08±0.03
Furans
2-pentyl furan	11.569	0.05±0.01	0.12±0.09	0.09±0.05	MS+STD
2-n-octyl furan	17.797	ND	0.09±0.04	0.05±0.01	MS+STD
Total furans		0.05±0.01	0.13±0.06	0.13±0.05

QG1+, quality grade 1+; QG1, quality grade 1; QG2, quality grade 2; ND, not detected.

¹⁾Identification method: The compounds were identified by either mass spectra (MS) from library or authentic standards (STD).

^a,bMeans within a same row with different letters differ significantly at (p<0.05).