Table 1.
No | Compounds | Retention Time (s) | Mass 3 | References | Odour Strength 4 | Odour Description 4 | |
---|---|---|---|---|---|---|---|
1D 1 | 2D 2 | ||||||
1 | Pentanal C1 | 435 | 2.11 | 58 | [20,21,22,23,24,25] | High, 1% | Bready; fruity; nutty; berry |
2 | Acetic acid | 455 | 4.41 | 60 | [21,22,26] | High, 10% | Pungent; sour; vinegar |
3 | 2-Methylfuran C2 | 495 | 2.59 | 53 | [22] | Medium, 1% | Ethereal; acetone; chocolate |
4 | Pyridine C3 | 505 | 2.60 | 79 | [21,23,25,27] | Very high, 0.01% | Sour; putrid; fishy; amine |
5 | 1-Pentanol C4 | 520 | 2.47 | 42 | [12,21,23,25] | High, 10% | Pungent; fermented; bread; yeasty; fusel; winey |
6 | Toluene C5 | 525 | 2.14 | 91 | [21,22,23] | Sweet | |
7 | 2-Hexanone | 540 | 2.16 | 43 | [23,28] | High, 1% | Fruity; fungal; meaty; buttery |
8 | Hexanal C6 | 550 | 2.17 | 56 | [12,20,21,22,23,24,25,26,27,29,30,31] | High, 1% | Fresh; green; fatty; grass; leafy; fruity; sweaty |
9 | Furfural C7 | 585 | 3.38 | 95 | [23,25,26,27,32,33] | Medium, 1% | Sweet; woody; almond; fragrant baked; bread |
10 | 2-Methylpyridine | 590 | 2.45 | 93 | [23,27] | Astringent; hazelnut | |
11 | 1,3-Octadiene * | 600 | 1.99 | 54 | |||
12 | 1-Hexanol C8 | 645 | 2.45 | 56 | [12,23,29] | Medium, 10% | Pungent; ethereal; fusel; oil; fruity; alcoholic; sweet with a green top note |
13 | 1,3-Dimethylbenzene | 655 | 2.14 | 91 | [12,23,29] | Fried; medicine; nut; plastic; rancid | |
14 | 2-Heptanone C9 | 665 | 2.18 | 58 | [20,21,22,23,26,27,29] | High, 10% | Cheesy; fruity; spicy; sweet; herbal; coconut; woody |
15 | 2-Butylfuran C10 | 680 | 2.09 | 81 | [21,23,29,30] | Medium | Mild; fruity; wine; sweet; spicy |
16 | Heptanal C11 | 680 | 2.17 | 70 | [20,21,22,23,24,25,26,27,29] | High, 1% | Fresh; fatty; green; herbal |
17 | Styrene | 680 | 2.30 | 104 | [21,26,27] | ||
18 | 1,2-Dimethylbenzene C12 | 685 | 2.18 | 91 | [12,21] | Geranium | |
19 | 2-Acetyl-1-pyrroline C13 | 700 | 2.45 | 43 | [12,20,21,23,24,25,30,31,34] | Medium, 1% | Popcorn; toasted; grain; malty |
20 | 2-Methyl-5-isopropenylfuran C14 | 730 | 2.18 | 122 | [22] | Medium | Sweet; spearmint; herbal |
21 | (Z)-2-heptenal C15 | 750 | 2.32 | 41 | [20,22,23,29] | High, 1% | Pungent; green; vegetable; fresh; fatty |
22 | Benzaldehyde C16 | 750 | 2.98 | 105 | [20,21,23,25,26,27,29,30] | High, 10% | Bitter; almond; burnt sugar; cherry; malt; roasted pepper |
23 | 1-Ethyl-4-methylbenzene | 775 | 2.14 | 105 | [21,23] | ||
24 | 1-Heptanol C17 | 775 | 2.39 | 70 | [12,22,27,30] | Medium, 10% | Musty; leafy; herbal; green; sweet; woody |
25 | Benzonitrile | 775 | 3.27 | 103 | [29] | ||
26 | 1-Octen-3-ol C19 | 785 | 2.43 | 57 | [20,22,23,24,25,27,30,31] | High, 10% | Earthy; green; oily; vegetative; fungal |
27 | 6-Methyl-5-hepten-2-one C18 | 785 | 2.26 | 43 | [20,21,23,24,25] | Medium, 10% | Citrus; green; musty; lemongrass |
28 | Phenol C20 | 790 | 2.99 | 66 | [12,23,26,29] | High, 0.01% | Phenolic |
29 | 2-Octanone C21 | 795 | 2.18 | 58 | [22,23,25] | Med, 10% | Earthy; weedy; natural; woody |
30 | 2,4,6-Trimethylpyridine ** | 800 | 2.30 | 121 | |||
31 | 2-Pentylfuran C22 | 805 | 2.09 | 81 | [20,21,22,23,24,27,29,30] | High, 10% | Fruity, green, earthy beany with vegetable-like nuances |
32 | α-Myrcene C23 | 810 | 2.02 | 93 | [35] | Med, 5% | Peppery; terpene; spicy; balsam |
33 | Octanal C24 | 810 | 2.17 | 43 | [20,21,22,23,24,25,27,29,30,31] | High, 1% | Waxy; citrus; orange peel; fatty |
34 | 1,2,3-Trimethylbenzene | 815 | 2.18 | 105 | [22,23] | Pesticide | |
35 | α-Phellandrene | 835 | 2.03 | 93 | [29] | Med, 5% | Citrus; herbal; terpene; green; woody; peppery |
36 | 1,2,4-Trimethyl benzene | 850 | 2.22 | 105 | [23,30] | pesticide, plastic | |
37 | 1-Nitro-hexane | 850 | 2.49 | 43 | [30] | ||
38 | 3-Octen-2-one C25 | 850 | 2.30 | 55 | [21,22,23,27] | High, 1% | Earthy; spicy; herbal; sweet; mushroom |
39 | Benzene acetaldehyde C26 | 850 | 3.00 | 91 | [21,22,25,27] | High, 2% | Honey; floral; rose; sweet; cocoa |
40 | 1-Ethyl-2-methylbenzene | 860 | 2.26 | 105 | [22] | ||
41 | Isobutyl nonyl ester oxalic acid | 860 | 2.16 | 57 | [24] | ||
42 | Eucalyptol C27 | 865 | 2.06 | 43 | [20,27] | High, 10% | Eucalyptus; herbal; camphor |
43 | (E)-2-octenal C28 | 875 | 2.30 | 70 | [20,21,22,23,24,25,26,27,29,30] | High, 1% | Fresh; cucumber; fatty; green; herbal |
44 | Indene | 875 | 2.46 | 115 | [26] | ||
45 | (Z)-3,7-Dimethyl-1,3,6-octatriene C29 | 880 | 2.05 | 93 | [26] | Medium | Tropical; green; woody with vegetable nuances |
46 | 1-Phenyl-ethanone C30 | 885 | 2.93 | 105 | [25,27,29] | ||
47 | Dihydromyrcenol | 900 | 2.26 | 59 | |||
48 | 1-Octanol C31 | 900 | 2.33 | 56 | [20,21,22,23,25,27,30,31] | Medium 10% | Waxy; green; orange; rose; mushroom |
49 | Decane | 910 | 2.11 | 57 | [21,22,23,30] | Alkane; odour | |
50 | 3,5-Octadien-2-one C32 | 915 | 2.52 | 95 | [34] | High, 1% | Fruity; fatty; mushroom |
51 | Guaiacol C33 | 915 | 3.57 | 109 | [32,36] | High, 1% | Phenolic; smoke; spice; vanilla woody |
52 | 2-Nonanone C34 | 920 | 2.17 | 58 | [20,22,23] | Medium | Fresh; sweet; green; weedy earthy herbal |
53 | 6-Methyl-3,5-heptadiene-2-one C35 | 930 | 2.54 | 109 | [22,25] | Citrus; fruits | |
54 | 1-octen-3-yl acetate * | 940 | 2.08 | 43 | Medium | Fresh; green; herbal; lavender; fruity oily | |
55 | α-Terpinolene | 935 | 2.06 | 93 | [35] | Medium, 1% | Sweet; fresh; piney; citrus with a woody old lemon peel nuance |
56 | Nonanal C36 | 935 | 2.17 | 57 | [12,20,21,22,23,25,26,27,30] | High, 1% | Aldehydic; citrus; cucumber fattiness |
57 | Linalool C37 | 935 | 2.33 | 93 | [23,27] | Medium | Citrus; floral; sweet; woody; green; blueberry |
58 | Decane | 940 | 2.08 | 57 | [22,23,26,30] | ||
59 | Tridecane | 950 | 1.93 | 43 | [23,29,30] | ||
60 | Tetradecane | 955 | 1.92 | 57 | [12,21,22,23,29,30] | ||
61 | o-Cymene C38 | 970 | 2.15 | 119 | [29] | ||
62 | (E)-2-nonenal C39 | 995 | 2.30 | 55 | [20,21,23,24,25,27,30,31] | High, 1% | Fatty; green cucumber; citrus |
63 | 1,2,3,4-tetramethyl-benzene | 1005 | 2.24 | 119 | [21,23] | ||
64 | 2-Decen-1-ol C40 | 1010 | 2.14 | 82 | [24] | Medium | Waxy; fresh air; citrus |
65 | 2-Pentylthiophene | 1010 | 2.17 | 97 | High 0.1% | Fruity; fatty; cranberry | |
66 | Ethyl ester benzoic acid C41 | 1010 | 2.53 | 105 | [25] | Medium | Fruity; dry musty; sweet; wintergreen |
67 | 1-Nonanol | 1015 | 2.30 | 56 | [12,22,23,27,30] | Medium | Fresh; fatty; floral; rose; orange; dusty; wet; oily |
68 | Undecane | 1025 | 1.94 | 43 | [21,22,23,29] | Alkane odour | |
69 | (+)-Isomenthol * | 1030 | 2.38 | 71 | Medium, 10% | Mentholic; musty; woody | |
70 | 2-Decanone | 1035 | 2.17 | 58 | [23,27] | Medium | Orange; floral; fatty; peach |
71 | Ethyl ester octanoic acid C42 | 1040 | 2.09 | 88 | [21] | Medium | Fruity; wine; waxy; sweet; apricot banana; brandy; pear |
72 | Naphthalene | 1040 | 2.73 | 128 | [21,23,24,26,27,29,30,34] | Naphthalene | |
73 | Estragole * | 1045 | 2.44 | 148 | Medium | Sweet; sassafrass; anise spice; green herbal; fennel | |
74 | Decanal C43 | 1050 | 2.17 | 57 | [20,21,23,25,26,27,29,30,31] | High, 1% | Sweet, aldehydic, orange, waxy and citrus rind |
75 | 2,4-Nonadienal C44 | 1055 | 2.50 | 81 | [21,22,23,30,31] | High, 0.1% | Fatty; green cucumber |
76 | Dodecane C45 | 1065 | 1.94 | 43 | [21,22,23,30] | Alkane odour | |
77 | Benzothiazole C46 | 1075 | 3.36 | 69 | [21,23,24,34] | High, 0.1% | Sulphur-like; rubbery; vegetable; Cooked; nutty; coffee; meat |
78 | (Z)-2-decenal C47 | 1110 | 2.28 | 70 | [22,23,31] | High, 0.1% | Waxy; fatty; earthy; green; mushroom |
79 | Citral C48 | 1115 | 2.41 | 69 | [22,23] | Medium | Sharp lemon; sweet |
80 | Ethyl ester decanoic acid | 1115 | 2.22 | 88 | [21] | Medium | Sweet; waxy; fruity; apple; grape; oily; brandy |
81 | Nonanoic acid | 1115 | 3.90 | 73 | [23,25,26] | Medium, 10% | Waxy; dirty; cheese cultured; dairy |
82 | 1-Decanol | 1130 | 2.02 | 83 | [23,24] | Medium | Fatty; waxy; floral; orange sweet; clean watery |
83 | Trans-anethole * | 1140 | 2.57 | 148 | High, 10% | Sweet anise; liquorice | |
84 | 1H-indole C49 | 1145 | 1.54 | 117 | [21,22,24,30] | High, 1% | Pungent; floral; animalic; musty; character |
85 | 2-Butyl-1-octanol | 1160 | 1.95 | 57 | [22] | Solvents | |
86 | Undecanal C50 | 1160 | 2.14 | 82 | [21,23] | High, 1% | Waxy; soapy; floral; aldehydic; citrus; green; fatty |
87 | 2,4-Decadienal C51 | 1165 | 2.46 | 81 | [23,25,26,27,30,31] | High, 1% | Orange; sweet; fresh; citrus fatty; green |
88 | 2,6-Dimethyl-heptadecane | 1180 | 1.95 | 57 | [22] | ||
89 | Dihydro-5-pentyl-2(3H)-furanone | 1200 | 2.95 | 85 | [21,26] | Medium | Creamy; oily with fatty nuances |
90 | Decanoic acid | 1215 | 3.74 | 60 | [25,26] | Medium, 1% | Unpleasant rancid; sour; fatty; citrus |
91 | E-2-undecenal | 1215 | 2.27 | 70 | [23,26,30] | High, 1% | Fresh fruity; citrus; orange peel |
92 | Pentadecane | 1220 | 1.94 | 57 | [21,22,23] | ||
93 | Geranyl acetate | 1230 | 2.22 | 69 | [20,23,31] | Medium, 5% | Floral; rosy; waxy; herbal and green with a slight cooling nuance |
94 | Hexadecane | 1365 | 1.94 | 57 | [21,22,23,30] | Alkane; root | |
95 | Biphenyl | 1240 | 2.72 | 154 | [30] | High, 0.1% | Pungent; rose; green; geranium |
96 | 1-ethyl-naphthalene | 1260 | 2.60 | 156 | [30] | fatty; earthy | |
97 | Dodecanal | 1260 | 2.16 | 57 | [26,31] | High, 10% | Soapy; waxy; aldehydic; citrus; green; floral |
98 | (E)-6,10-dimethyl-5,9-undecadien-2-one | 1300 | 2.26 | 43 | [21,25,30] | Medium | Fresh; rose; leaf; floral; green; magnolia; aldehydic |
99 | 1,3-dimethyl-naphthalene | 1305 | 2.71 | 141 | [30] | ||
100 | Trans-caryophyllene | 1305 | 2.08 | 93 | [21] | Medium | Spicy; woody and terpenic |
101 | α-Ionone | 1340 | 2.36 | 177 | [31] | Medium, 10% | Floral; woody; sweet; fruity; berry; tropical; beeswax |
102 | 2,4-Bis(1,1-dimethylethyl)-phenol | 1355 | 2.95 | 191 | [24] | Phenolic | |
103 | Methyl ester dodecanoic acid | 1365 | 2.123 | 74 | [21] | Medium | Waxy; soapy; creamy; coconut; mushroom |
104 | α-Copaene | 1370 | 2.11 | 105 | [35] | Medium | Woody; spicy; honey |
105 | Lilyall | 1370 | 2.46 | 189 | [30] | Medium | Floral; muguet; watery; green; powdery; cumin |
106 | 1S,cis-calamenene | 1385 | 2.19 | 159 | [21] | ||
107 | 2,3,6-Trimethyl-naphthalene | 1405 | 2.65 | 155 | [30] | Fruity; dry | |
108 | 2-Undecanone | 1515 | 2.18 | 58 | [20,21,22,23] | Waxy; fruity; creamy; fatty; floral | |
109 | Methyl ester decanoic acid | 1535 | 2.14 | 74 | [21] | Medium | Oily; wine; fruity; floral |
110 | 2,6-Diisopropylnaphthalene | 1555 | 2.42 | 197 | [21] | ||
111 | Tetradecanoic acid | 1560 | 3.22 | 60 | [25] | Low, 10% | Faint; waxy and fatty with a hint of pineapple and citrus peel |
112 | 2-Ethylhexyl salicylate | 1610 | 2.39 | 120 | [30] | Low | Mild; orchid; sweet; balsam |
113 | 6,10,14-Trimethyl-2-pentadecanone | 1630 | 2.16 | 58 | [22] | Low | Oily; herbal; jasmine; celery; woody |
114 | 2-Pentadecanone | 1670 | 2.25 | 58 | [30] | Medium, 10% | Fresh; jasmine; celery |
115 | Methyl ester hexadecanoic acid | 1690 | 2.22 | 74 | [21] | ||
116 | Hexadecanoic acid | 1715 | 3.67 | 60 | [21,23,30] | Low, 1% | Low heavy waxy with a creamy; candle waxy nuance |
117 | Hexadecanoic acid, ethyl ester | 1740 | 2.26 | 88 | [25] | Low | mild waxy; fruity; creamy milky balsam |
118 | 1-Hexadecanol | 1920 | 2.26 | 97 | [24] | Low | Waxy; floral |
119 | Heptacosane | 2215 | 2.45 | 71 | [22] |
* Reported for the first time in rice samples and the identification was confirmed by standard compounds. ** Internal standard. 1 1D refers to one-dimensional gas chromatography (GC) separation (in the first column). 2 2D refers to two-dimensional gas chromatography (GC×GC) separation (in the second column). 3 Unique mass spectra. The NIST Mass Spectral Database was used to identify volatile compounds from GC×GC coupled with time-of-flight mass spectrometry (TOFM) analyses. 4 www.thegoodscentscompany.com. Cn Odour-active compounds for principal component analysis PCA (n = running number of selected compounds). Key-marker compounds are presented in bold letters.