Table 1.

Volatile and odor-active compounds of the conventional passion fruit in the 1/3, 2/3 and 3/3 yellow skin color stages of ripeness

Peak	RI1	RI2	Compound3	Aroma description	GC–FID4			GC–O5
					1/3	2/3	3/3	1/3	2/3	3/3
1	922	<800	ethyl propanoatea,b,c	Not detected by OSME	0.92	1.73	3.32	–	–	–
2	932	<800	propyl acetatea,b,c	Skin, passion fruit	nd–0.20	0.26	6.40	4.62	6.65	7.15
4	939	<800	methyl butanoatea,b,c	Passion fruit/fruity	12.47	8.31	2.34	3.40	3.47	2.11
6	974	<800	2-methylpropyl acetatea,b,c	Passion fruit	9.69	16.12	11.41	–	0.93	0.93
9	1019	803	ethyl butanoatea,b,c	Sweet/strawberry	435.71	621.08	1047.15	8.77	8.85	8.49
10	1027	<800	2-methyl-3-buten-2-olb,c	Not detected by OSME	11.24	18.23	18.01	–	–	–
12	1066	815	butyl acetatea,b,c	Green, sweet	5.98	11.60	15.44	–	2.77	4.72
14	1073	<800	hexanala,b,c	Not detected by OSME	51.93	19.60	13.70	–	–	–
15	1096	<800	diethyl carbonateb,c	Plastic	nd–0.32	0.72	0.79	3.37	5.23	6.60
17	1125	886	o-xyleneb,c	Plastic	tr–0.15	nd–0.72	0.94	–	–	–
18	1131	<800	methyl 2-methylbutanoateb,c	Not detected by OSME	1.19	4.31	3.40	–	–	–
19	1155	<800	1-butanola,b,c	Sweet/fruity	1.20	2.72	6.02	2.32	2.08	3.26
20	1172	993	beta-myrcenea,b,c	Citric/fruity	13.99	38.03	28.49	–	–	1.57
22	1175	934	methyl hexanoatea,b,c	Strawberry, earthy	0.84	1.52	5.87	–	0.91	1.55
23	1184	1029	D-limonenea,b,c	Not detected by OSME	22.60	41.87	22.56	–	–	–
24	1210	972	butyl butanoatea,b,c	Sweet	1.55	2.02	4.33	–	–	1.15
25	1228	1001	ethyl hexanoatea,b,c	Syrup, guarana	54.38	70.88	160.33	6.42	6.13	6.61
26	1244	1052	cis-beta-ocimeneb,c	Not detected by OSME	8.75	15.31	17.18	–	–	–
28	1268	1019	hexyl acetatea,b,c	Floral	15.03	38.10	62.22	–	–	0.94
29	1274	1006	octanala,b,c	Sweet, acid	1.09	2.09	2.05	–	1.54	1.61
30	1275	990	ethyl cis-3-hexenoateb,c	Fruity/floral	nd–0.45	nd–tr	tr–0.35	2.00	2.06	1.52
32	1300	1009	trans-3-hexenyl acetateb,c	Fruity, citrus	0.51	1.42	2.17	–	–	1.24
33	1309	991	cis-3-hexenyl acetateb,c	Fruity, green	15.37	34.02	42.77	2.33	2.53	3.04
34	1328	1021	ethyl trans-2-hexenoateb,c	Floral	1.18	1.55	1.32	–	–	–
36	1355	870	1-hexanola,b,c	Passion fruit, skin	13.41	25.66	52.21	–	–	2.58
37	1362	1039	trans-3-hexen-1-olb,c	Not detected by OSME	1.18	1.84	3.40	–	–	–
38	1382	855	cis-3-hexen-1-ola,b,c	Passion fruit, grass	4.77	9.39	11.95	2.31	4.26	4.35
39	1402	1193	butyl hexanoatea,b,c	Unripe fruit	0.51	2.38	4.25	–	–	1.72
40	1406	1193	hexyl butanoatea,b,c	Not detected by OSME	5.38	18.12	43.99	–	–	–
42	1449	1198	ethyl octanoatea,b,c	Earthy	0.23	0.34	1.25	3.88	3.43	3.26
43	1452	1185	cis-3-hexenyl butanoateb,c	Not detected by OSME	2.25	5.84	10.94	–	–	–
46	1495	1385	alpha-copaeneb,c	Green, fruity	tr–0.18	tr–0.45	0.97	1.52	1.12	0.98
47	1515	971	benzaldehydeb,c	Lavander	0.77	1.29	1.38	–	1.14	0.87
A	1537	–	ni	Citric	nd	nd	nd	1.96	2.09	1.32
B	1570	–	ni	Citric, lavander	nd	nd	nd	–	–	1.59
48	1575	1100	beta-linaloola,b,c	Sweet, citrus	0.73	2.27	2.36	1.63	2.02	2.42
51	1598	1387	hexyl hexanoatea,b,c	Synthetic, rubber	1.95	7.22	18.11	1.11	1.12	1.11
52	1646	1381	cis-3-hexenyl hexanoateb,c	Green, citric	0.70	2.31	4.55	–	1.44	1.40
53	1689	1487	germacrene Db,c	Passion fruit	0.36	0.23	0.28	0.94	1.75	1.85
C	1705	–	ni	Passion fruit	nd	nd	nd	1.17	1.12	0.50
54	1715	1195	alpha-terpineola,b,c	Passion fruit/leafy	nd -0.92	0.72	2.59	1.44	2.87	4.48
56	1753	–	ni	Green, passion fruit	nd–0.30	nd	nd	–	1.80	2.54
57	1771	–	ni	Green, leafy	nd	nd–0.52	nd	–	0.98	2.11
D	1785	–	ni	Green, sweet	nd	nd	nd	–	1.09	1.57
E	1813	–	ni	Passion fruit	nd	nd	nd	1.73	1.51	1.31
58	1840	–	ni	Sweet, molasses	nd	nd–0.34	nd	4.27	3.83	3.57
F	1913		ni	Rubber, passion fruit	nd	nd	nd	–	0.87	1.92
59	1941	–	ni	Sweet	0.65	1.11	0.90	–	–	–
G	1960	–	ni	Fruity, peach	nd	nd	nd	2.44	2.15	2.31
60	1962	–	ni	Passion fruit, sweet	nd	0.33	nd	–	–	0.10
61	1963	1487	dodecanolb,c	Sweet	0.93	1.31	1.07	1.36	1.33	0.78
63	2072	–	ni	Candy floss	nd–0.21	0.30	0.54	2.33	4.88	4.49
64	2166	–	ni	Candy floss/caramel	nd	nd	tr	–	–	2.22
65	2188	–	methyl hexadecanoateb,c	Metalic/solvent	nd–0.22	nd–0.25	0.38	–	–	–
66	2217	–	ni	Solvent	nd	nd	tr	4.72	1.89	3.74

¹RI = retention index of peak in the DB-Wax column

²RI = retention index of peak in the DB-5 column; - not calculated

³Compounds have identical number in the chromatogram and aromagram. Letters were attributed to the odor active compounds not correlated to the volatile compounds detected by GC-FID

⁴GC-FID: relative area of peak (n = 3) in the GC-FID, multiplied by 100, nd compound not detected, ni compound not identified, tr trace, relative area of peak < 0.1

⁵GC-O: maximum odoriferous intensity, ≥ 4.0: between moderate and strong, 3.0 to 3.9: moderate, 0.1 to 2.9: weak, – none (not detected by OSME)

^acompound identified by pure standards

^bcompound identified by mass spectrometry

^ccompound identified by calculating the retention index