GC-O-MS Analysis of Aroma-Active Compounds of Chinese Almonds Obtained by Different Pretreatment Methods

Table 1

Identification and FD factors for volatile aroma compounds of almonds.

No.	Component	RI^a		Reference RI		Odor^b	FD factor^c			Identification
		HP-INNOWax	DB-5	HP-INNOWax	DB-5		SAFE	SPME	SDE
Aldehydes
1	Hexanal	1089	805	1081	805	Fresh, green	243	—	243	MS, RI, O, S
2	trans-2-Pentenal	1136	757	1134	N	Green	—	—	3	MS, RI, O, S
3	Heptaldehyde	1189	901	1186	901	Fatty, green	81	—	—	MS, RI, O, S
4	2-Hexenal	1222	854	1226	N	Fatty, green	—	—	3	MS, RI, O, S
5	1-Nonanal	1392	1104	1403	1101	Fatty, rose	2187	243	2187	MS, RI, O, S
6	2-Furaldehyde	1439	818	1439	833	Sweet, woody	243	9	9	MS, RI, O, S
7	(2E, 4E)-Hepta-2,4-dienal	1493	1011	1497	1017	Fatty, green	3	—	—	MS, RI, O, S
8	Benzaldehyde	1525	973	1530	961	Sweet, cherry	729	81	—	MS, RI, O, S
9	trans-2-Nonenal	1533	1162	N	1168	Fatty, green	—	—	729	MS, RI, O, S
10	5-Methylfurfural	1571	978	1558	957	Sweet,	27	9	9	MS, RI, O, S
11	Phenylacetaldehyde	1641	1045	1663	1044	Green, sweet, floral	729	243	2187	MS, RI, O, S
12	2,4-Decadienal	1826	1319	N	1309	Fatty	—	—	81	MS, RI, O, S
13	Pyrrole-2-carboxaldehyde	2022	1031	N	N	Musty, beef	1	1	—	MS, RI, O, S
14	(E)-Cinnamaldehyde	2041	1266	N	1266	Sweet, candy	—	3	1	MS, RI, O, S
15	Cinnamaldehyde	2045	1260	N	N	Sweet, honey	3	—	—	MS, RI, O, S
Alcohols
16	2-Methyl-3-buten-2-ol	1039	600	1048	N	Grass, greasy	—	—	3	MS, RI, O, S
17	1-Penten-3-ol	1154	671	N	716	Green	—	—	3	MS, RI, O, S
18	Pentanol	1246	760	1244	761	Greasy, sweet	243	—	—	MS, RI, O, S
19	1-Hexanol	1346	858	1340	869	Greasy, fruity	729	—	—	MS, RI, O, S
20	3-Hexen-1-ol	1378	845	1363	858	Green, leaf	9	—	—	MS ,RI, O
21	2-Ethylhexanol	1480	1028	1490	1028	Orange, floral	3	—	—	MS, RI, O, S
22	2,3-Butanediol	1531	800	1553	767	Fruity, creamy	3	—	—	MS, RI, O, S
23	Linalool	1538	1098	1551	1099	Floral	2187	243	2187	MS, RI, O, S
24	Alpha-Terpineol	1691	1192	1718	1195	Rosin, floral	9	1	9	MS, RI, O, S
25	2,2,6-Trimethyl-6-vinyltetrahydro-2h-pyran-3-ol	1732	1163	N	N	Floral, honey	729	81	81	MS, RI, O, S
26	Nerol	1789	1228	1757	1228	Sweet, neroli	—	—	3	MS, RI, O, S
27	Benzyl alcohol	1880	1045	1898	1032	Floral	243	27	8	MS, RI, O, S
28	2-Phenylethanol	1906	1117	1872	1117	Floral	81	27	27	MS, RI, O, S
29	3-Phenyl-1-propanol	2040	1232	N	1232	Sweet, balsam	3	—	—	MS, RI, O, S
30	2-Propen-1-ol, 3-phenyl-	2280	1312	N	1312	Sweet, balsam	27	—	—	MS, RI, O, S
Ketones
31	3-Hexanone	1063	783	N	784	Sweet, fruity	—	—	9	MS, RI, O, S
32	2-Butanone	1287	1362	908	N	Sweet, greasy	9	—	—	MS, RI, O, S
33	Acetophenone	1653	1078	1671	1065	Sweet, spicy	243	—	—	MS, RI, O, S
34	Damascone	1817	1362	1830	N	Sweet, fruity	—	—	81	MS, RI, O, S
Esters
35	Dihydrofuran-2(3H)-one	1633	917	N	908	Creamy, greasy	9	1	1	MS, RI, O, S
36	Gamma-Caprolactone	1704	1047	N	N	Grass, coconut	3	—	—	MS, RI, O, S
37	Benzyl acetate	1726	1170	1689	1165	Sweet, floral	—	9	—	MS, RI, O, S
38	Methyl salicylate	1775	1198	1751	1198	Sweet, beer	27	27	27	MS, RI, O, S
39	Gamma-nonanoic lactone	2032	1344	N	1344	Fruity, creamy	243	—	—	MS, RI, O, S
40	Pentadecanoic acid, ethyl ester	2144	1880	N	1880	Honey, sweet	—	—	9	MS, RI, O, S
41	Methyl palmitate	2208	1921	N	1921	Greasy, waxy	27	3	3	MS, RI, O, S
42	Ethyl palmitate	2247	1975	2250	1975	Waxy	—	9	9	MS, RI, O, S
43	Dihydroactinidiolide	2355	1479	N	1486	Plum	81	81	27	MS, RI, O, S
44	Methyl oleate	2439	2106	N	2100	Fatty	—	—	3	MS, RI, O, S
45	Ethyl linoleate	2523	2164	N	2155	Fatty, fruity	—	—	27	MS, RI, O, S
46	Benzyl benzoate	2636	1750	2655	1775	Sweet, balsam	—	81	—	MS, RI, O, S
Terpenoids
47	Myrcene	1164	992	1169	992	Spicy, balsam	—	81	81	MS, RI, O, S
48	Styrene	1260	911	N	889	Sweet, balsam	243	—	9	MS, RI, O, S
49	Alpha-pinene	1489	1377	1022	940	Woody, honey	—	—	9	MS, RI, O, S
50	Beta-caryophyllene	1594	1162	1614	1420	Sweet, woody	—	—	27	MS, RI, O, S
51	Delta-cadinene	1754	1526	1764	1526	Musk, grass	—	9	9	MS, RI, O
Acids
52	Acetic acid	1446	1020	1427	625	Spicy, sour	9	1	—	MS, RI, O, S
53	Hexanoic acid	1833	1020	1831	1020	Sour, fatty	81	27	9	MS, RI, O, S
54	Heptanoic acid	1941	1076	N	1076	Sour	27	9	3	MS, RI, O, S
55	Octanoic acid	2049	1186	2039	1186	Fatty, waxy	27	27	—	MS, RI, O, S
56	Nonanoic acid	2153	1283	2192	1293	Waxy, cheese	27	9	2187	MS, RI, O, S
57	Benzoic acid	2438	1170	N	1170	Balsam	27	3	1	MS, RI, O, S
58	Myristicin	1681	1762	N	1516	Waxy, fatty	—	—	3	MS, RI, O, S
Other
59	2-Pentylfuran	1230	993	1231	993	Fruity, green	—	—	243	MS, RI, O, S
60	2,5-Dimethylpyrazine	1324	928	N	928	Cocoa, roasted	9	—	—	MS, RI, O, S
61	2,6-Dimethylpyrazine	1328	723	N	N	Cocoa, roasted	9	9	—	MS, RI, O, S
62	Pyrazine,2-ethyl-6-methyl-	1384	834	N	991	Potato	27	—	—	MS, RI, O, S
63	2,3,5-Trimethylpyrazine	1403	840	1411	1005	Nuts	9	81	—	MS, RI, O, S
64	Linalool oxide	1468	1080	N	N	Mud, floral	81	27	—	MS, RI, O
65	1-(Furan-2-yl)ethanone	1500	911	N	N	Sweet, balsam	—	—	1	MS, RI, O, S
66	Guaiacol	1856	1089	1884	1089	Balsam, vanilla	243	—	—	MS, RI, O, S
67	2-Methoxy-4-methylphenol	1953	1207	1982	1157	Clove	9	81	—	MS, RI, O, S
68	1-(1H-Pyrrol-2-yl)ethanone	1968	1072	N	1060	Musty, nuts	3	3	3	MS, RI, O, S
69	Phenol	1998	1005	N	1072	Plastic	1	1	—	MS, RI, O, S
70	Eugenol	2161	1348	2120	1356	Sweet, balsam	2187	243	729	MS, RI, O, S
71	4-Ethylphenol	2167	1178	N	1178	Beaver	—	—	81	MS, RI, O, S
72	4-Ethyl-2-methoxyphenol	2191	1309	N	1270	Woody, green	—	243	729	MS, RI, O, S
73	2,4-Di-tert-butylphenol	2298	1512	N	1502	Phenol	27	27	9	MS, RI, O, S
74	Indole	2444	1295	N	1292	Animal, floral	—	—	81	MS, RI, O, S
75	Vanillin	2568	1396	N	1394	Sweet, vanilla	729	—	9	MS, RI, O, S

^aRI is calculated according to formula (1). Reference RI is from this website (https://webbook.nist.gov/). N, not found. ^bOdor characteristics were detected at the olfactory probe port. ^cFlavour dilution factor. —, not detected; MS, characterization by MS spectroscopy; RI, identification of the compound by comparing the RI value with the real compound; O, characterization of its odor by comparing it with the real compound by GC-O; S, characterization of the detected profile of the compound by comparing it with the standard.