Determination of Volatile Compounds in Foxtail Millet Sake Using Headspace Solid-Phase Microextraction and Gas Chromatography-Mass Spectrometry
Table 2
Concentrations and OAVs of volatile compounds in foxtail millet sake ().
RI
Compounds
Concentration (μg/L)
Percent (%)
RSD (%)
Threshold (μg/L)
OAV
Odor description
Identification
Esters
788
Ethyl acetate
5010.88 ± 869.10
19.80 ± 2.94
14.84
7500
0.67
Fruity, sweet
MS, IR, Std
1001
Hexanoic acid ethyl ester
261.53 ± 71.60
1.04 ± 0.31
29.37
5
52.31
Fruity, sweet
MS, IR, Std
1125
Octanoic acid methyl ester
1370.94 ± 347.33
5.45 ± 1.49
27.39
200
6.85
Pineapple, pear
MS, IR, Std
1170
Benzoic acid ethyl ester
15.85 ± 1.63
0.06 ± 0.01
10.61
ND
MS, IR, Std
1179
Butanedioic acid diethyl ester
4250.87 ± 633.23
16.84 ± 2.53
15.01
100000
0.04
Floral
MS, IR, Std
1271
Pentanedioic acid diethyl ester
20.52 ± 1.48
0.08 ± 0.00
2.82
ND
MS, IR, Std
1355
Benzenepropanoic acid ethyl ester
20.17 ± 1.22
0.08 ± 0.00
0.85
40
0.50
Fruity, floral
MS, IR
1397
Decanoic acid ethyl ester
22.40 ± 3.47
0.09 ± 0.01
16.44
200
0.11
Fruity, fatty
MS, IR, Std
1936
Hexadecanoic acid ethyl ester
19.86 ± 2.28
0.08 ± 0.01
13.23
ND
MS, IR
Subtotal
10993.01 ± 631.34
43.52 ± 1.38
3.17
Alcohols
784
2,3-Butanediol
751.76 ± 152.05
3.00 ± 0.71
23.60
120000
0.01
Butter, creamy
MS, IR, Std
1092
2-Nonanol
62.06 ± 1.45
0.25 ± 0.02
6.60
58
1.07
Fatty
MS, IR, Std
1040
2-Ethyl-1-hexanol
71.14 ± 1.21
0.28 ± 0.02
5.66
270000
0.00
Mild, oily
MS, IR, Std
1120
Phenylethyl alcohol
7272.82 ± 1236.76
28.71 ± 3.80
13.23
14000
0.52
Flowery, pollen
MS, IR, Std
1224
2-Decanol
24.35 ± 7.20
0.10 ± 0.03
31.94
40
0.61
Fatty
MS, IR, Std
1231
1-Phenoxypropan-2-ol
138.36 ± 12.71
0.55 ± 0.02
3.94
ND
MS, IR
Subtotal
8320.49 ± 1087.30
32.88 ± 3.09
9.41
Acids
1013
Hexanoic acid
69.53 ± 13.92
0.28 ± 0.06
20.62
3000
0.02
Cheese, rancid
MS, IR, Std
1240
Nonanoic acid
23.07 ± 2.31
0.09 ± 0.01
7.37
3000
0.01
Rancid, fatty
MS, IR, Std
1160
Benzenecarboxylic acid
42.18 ± 5.04
0.17 ± 0.01
7.35
85000
0.00
Strawberry, cherry
MS, IR
1373
Decanoic acid
24.75 ± 1.62
0.10 ± 0.00
1.70
15000
0.00
Fatty, unpleasant
MS, IR, Std
Subtotal
159.53 ± 15.97
0.63 ± 0.05
8.48
Aldehydes
968
Benzaldehyde
83.06 ± 6.29
0.33 ± 0.04
11.02
350
0.24
Sweet, fruity
MS, IR, Std
1046
Benzeneacetaldehyde
11.35 ± 1.39
0.05 ± 0.01
14.40
4
2.84
Sweet, floral
MS, IR
1206
Decanal
8.27 ± 2.40
0.03 ± 0.01
26.05
1.5
5.51
Green, citrus
MS, IR, Std
1409
Dodecanal
24.72 ± 1.59
0.10 ± 0.01
8.86
2
12.36
Fatty, woody
MS, IR, Std
Subtotal
127.40 ± 6.92
0.51 ± 0.04
8.43
Hydrocarbons
1200
Dodecane
235.88 ± 46.28
0.93 ± 0.16
17.25
ND
MS, IR, Std
1300
Tridecane
199.00 ± 30.11
0.79 ± 0.09
11.60
ND
MS, IR, Std
1400
Tetradecane
94.59 ± 5.67
0.37 ± 0.02
6.33
ND
MS, IR, Std
1500
Pentadecane
129.28 ± 14.56
0.51 ± 0.08
15.96
ND
MS, IR, Std
1600
Hexadecane
2185.21 ± 123.32
8.65 ± 0.11
1.30
ND
MS, IR, Std
1700
Heptadecane
50.50 ± 8.13
0.20 ± 0.03
15.40
ND
MS, IR, Std
1706
2,6,10,14-Tetramethylpentadecane
67.60 ± 10.10
0.27 ± 0.04
14.18
ND
MS, IR
1800
Octadecane
22.58 ± 3.26
0.09 ± 0.01
16.61
ND
MS, IR, Std
2000
Eicosane
11.34 ± 0.70
0.05 ± 0.00
10.26
ND
MS, IR, Std
Subtotal
2995.98 ± 188.67
11.86 ± 0.35
2.96
ND
Benzene derivatives
888
Styrene
556.99 ± 108.56
2.21 ± 0.43
19.67
80
6.96
Floral, sweet
MS, IR, Std
1006
1,2,3-Trimethylbenzene
47.61 ± 9.59
0.19 ± 0.03
18.09
ND
MS, IR, Std
1291
2-Methylnaphthalene
128.23 ± 14.04
0.51 ± 0.06
11.41
20
6.41
Phenolic
MS, IR
1302
1-Methylnaphthalene
68.22 ± 4.93
0.27 ± 0.03
12.07
20
3.41
Phenolic
MS, IR, Std
1391
1-Ethylnaphthalene
9.83 ± 0.69
0.04 ± 0.00
2.56
ND
MS, IR
1442
2,3-Dimethylnaphthalene
20.47 ± 2.42
0.08 ± 0.01
8.85
ND
MS, IR
1559
1,6,7-Trimethylnaphthalene
85.71 ± 7.61
0.34 ± 0.03
8.34
ND
MS, IR
Subtotal
917.06 ± 139.82
3.63 ± 0.56
15.36
ND
MS, IR
Others
910
Butyrolactone
36.34 ± 0.71
0.15 ± 0.04
30.04
20000
0.00
Buttery
MS, IR, Std
1218
Benzothiazole
87.83 ± 10.45
0.35 ± 0.05
13.89
80
1.10
Gasoline, rubber
MS, IR, Std
Subtotal
124.17 ± 18.84
0.49 ± 0.09
18.13
Total
23637.64 ± 1597.74
93.52 ± 1.43
1.53
RI: retention indices on a DB-5 column. RSD: relative standard deviation. OAV: odor active value = concentration/odor threshold. ND: no odor description. a: odor thresholds and description reported by [22]. b: odor thresholds and description reported by [23].
