Identification and Aroma Impact of Volatile Terpenes in Moutai Liquor

Figures & data

TABLE 1 The neutral/basic fraction of Moutai liquor was separated into nine fractions by normal-phase liquid chromatography

Fraction^a	Solvent^b	Volume^c	Aroma descriptors^d
F1	100% pentane	0–50 mL	slight popcorn, herbal
F2	pen:die^e (95:5)	0–40 mL	fruity, floral
F3	pen:die (95:5)	40–80 mL	floral
F4	pen:die (95:5)	80–120 mL	cooked vegetables, slight floral
F5	pen:die (90:10)	0–70 mL	herbal
F6	pen:die (80:20)	0–50 mL	grass, sweet cheese, nutty
F7	pen:die (70:30)	0–50 mL	sweet
F8	diethyl ether	0–50 mL	acidic
F9	100% methanol	0–50 mL	ND^f

^aFraction: the fraction was labelled as F and an arabic number;

^bSolvent: the neutral/basic fraction was eluted by different volume ratio redistilled solvent;

^cVolume: the volume of solvent;

^dAroma descriptors: the characteristic aroma was described by panelists with filter paper strip sniffing;

^epen:die, pentane:diethyl ether(v/v);

^fND: odorless.

FIGURE 1 The spider plot of the aroma in Moutai liquor analyzed by GC–O and GC–MS.

TABLE 2 Identification of terpenes in Moutai liquor by normal-phase liquid chromatography coupled with GC–MS on both DB-FFAP and DB–5 columns

Number	Terpenes	Osme val^a	Aroma des^b	Fra^c	RIFFAP^d	RIDB-5^e	Identification^f
1	d-limonene	5	lemon	F1	1173	1020	MS, RI, aroma
2	p-cymene	4	lemon	F1	1264	1008	MS, RI, aroma
3	α-longipinene			F1	1463	1364	MS, RI
4	trans-linalool oxide			F8	1472	ND^g	MS, RI
5	α-gurjunene	6	woody	F1	1512	1413	MS, RI, aroma
6	linalool	11	floral	F6	1555	1087	MS, RI, aroma
7	α-cedrene	5	woody	F1	1561	1389	MS, RI, aroma
8	longifolene^h			F1	1570	1393	MS, RIL
9	β-elemene			F1	1585	1377	MS, RI
10	α-bergamotene^h			F1	1588	1420	MS, RIL
11	calarene^h			F1	1592	1424	MS, RIL
12	terpinen-4-ol	7	herbal	F7	1594	1160	MS, RI, aroma
13	β-caryophyllene	8	woody	F1	1600	1407	MS, RI, aroma
14	pulegone	10	floral	F6	1600	ND	MS, RI, aroma
15	(+)-aromadendrene	3	woody	F1	1604	1432	MS, RI, aroma
16	isophorone	5	woody	F6	1609	1114	MS, RI, aroma
17	γ-elemene^h			F1	1617	1378	MS, RIL
18	β-guaiene			F1	1620	1477	MS, RI
19	α-humulene	5	woody	F1	1651	1440	MS, RI, aroma
20	alloaromadendrene	4	woody	F1	1657	1469	MS, RI, aroma
21	β-cedrene			F1	ND	1404	MS, RI
22	γ-muurolene^h	5	herbal	F1	1694	1469	MS, RIL,aroma
23	α-chamigrene^h			F1	1701	1521	MS, RIL
24	α-terpineol	10	floral	F7	1701	1177	MS, RI, aroma
25	(-)-borneol	3	camphor	F7	1704	1159	MS, RI, aroma
26	α-muurolene^h	4	herbal	F1	1709	1497	MS, RIL, aroma
27	α-selinene^h			F1	1712	1496	MS, RIL
28	valencene			F1	1719	1498	MS, RI
29	β-bisabolene^h			F1	1725	1512	MS, RIL
30	β-chamigrene			F1	1728	1461	MS, RI
31	piperitone^h			F7	1741	1352	MS, RIL
32	germacrene D^h			F3	1742	1471	MS, RIL
33	γ-cadinene^h			F1	1751	1501	MS, RIL
34	δ-cadinene	3	woody	F1	1757	1509	MS, RIL, aroma
35	β-citronellol	9	floral	F8	1767	1429	MS, RI, aroma
36	nerol	6	floral	F5	1769	ND	MS, RI, aroma
37	α-curcumene^h			F1	1789	1467	MS, RIL
38	β-damascenone	15	floral	F3	1820	1369	MS, RI, aroma
39	dihydro-β-ionone	13	floral	F3	1833	1379	MS, RI, aroma
40	calamenene			F1	1848	1525	MS, RI
41	E-geranylacetone	12	floral	F3	1866	1461	MS, RI, aroma
42	geraniol	8	floral	F8	1871	ND	MS, RI, aroma
43	α-calacorene^h			F1	1904	1552	MS, RIL, aroma
44	β-ionone	11	violet	F3	1971	1491	MS, RI, aroma
45	α-cedrene epoxide			F5	2000	1586	MS, RI
46	ledol^h	8	sweet	F7	2013	ND	MS, RIL, aroma
47	E-nerolidol	11	floral	F7	2020	1568	MS, RI, aroma
48	α-cedrol	8	herbal	F7	2117	1594	MS, RI, aroma
49	α-cadinol^h			F8	2209	1652	MS, RIL, aroma
50	α-bisabolol			F7	2212	1692	MS, RI
51	β-eudesmol	6	woody	F7	2238	1657	MS, RI, aroma
52	farnesol	5	herbal	F7	2361	1730	MS, RI, aroma
53	(E,E)-farnesylacetone			F5	2376	1922	MS, RI
54	geranylgeraniol			F5	2785	2045	MS, RI
55	squalene			F1	3034	2834	MS, RI

^aOsme val: the aroma intensity values were the average values of 12 analyses (four panelists, three times);

^bAroma des: aroma descriptor was sniffed by each panelist;

^cFraction: terpenes were identified in major fraction;

^dRI_FFAP: retention indices were calculated on DB–FFAP column;

^eRI_DB-5: retention indices were calculated on DB–5 column;

RIL: retention indices were the literature;

^fIdentification: terpenes identified by MS (mass spectra), authentic standards, RI (retention index) and aroma descriptors;

^gND: not determined;

^hTentatively identified.

FIGURE 2 The peak areas of terpenes classes in Moutai liquor as a function of distinct SPME extraction efficiency: Peak areas of terpenes classes were extracted by different fiber types (2-a); peak areas of terpenes classes for the different analytes according to the extraction patterns (2-b); sample ethanol content (2-c); sampling extraction temperature (2-d); extraction time (2-e); desorption temperature (2-f).

TABLE 3 Calibration of standard curve datas of quantification method, R², LOD, LOQ, linearity range, and recovery rate of terpenes in Moutai liquor

Terpenes	IS^a	Slo^b (×10)	Int^c (×10^4)	R^2	n^d	Quant^e (m/z)	LOD^f (µg/L)	LOQ^g (µg/L)	Linearity range (µg/L)	Recovery rate (%)
Theaspirane	L-m	0.19	0.01	0.9999	6	138	0.0030	0.0101	0.73–23.42	99.74
linalool	L-m	3.98	3.00	0.9990	6	93	0.0412	0.1374	3.63–116.01	96.08
β-caryophyllene	L-ma	4.05	–2.00	0.9977	8	133	0.0408	0.1359	2.75–352.26	105.42
cis-thujopsene	L-ma	0.29	1.81	0.9985	8	119	0.0137	0.0457	1.89–242.03	94.89
α-gurjunene	L-ma	0.51	1.96	0.9962	6	204	0.0243	0.0811	2.13–68.18	108.41
alloaromadendrene	L-ma	0.77	2.41	0.9994	7	91	0.0377	0.1256	1.72–110.11	107.35
(+)-aromadendrene	L-ma	0.35	1.84	0.9969	6	133	0.0517	0.1723	2.39–76.48	100.98
β-cedrene	L-ma	0.92	4.08	0.9991	6	161	0.0123	0.0411	1.07–34.29	115.94
α-cedrene	L-ma	0.60	–2.00	0.9972	8	119	0.0029	0.0095	0.93–118.97	106.79
d-limonene	L-ma	5.25	15	0.9965	10	93	0.3429	1.1429	0.69–352.77	86.75
isophorone	L-m	6.49	4.10	0.9954	7	81	0.0429	0.1431	3.92–251.01	90.79
terpinen-4-ol	L-m	4.18	–32.00	0.9991	6	111	0.1104	0.3680	1.85–59.29	89.47
citral	L-m	2.88	–17.00	0.9982	5	69	0.0577	0.1923	1.67–26.75	93.45
β-citronellol	L-m	1.14	1.90	0.9994	7	69	0.0623	0.2075	1.17–74.62	97.90
nerol	L-m	3.11	17.00	0.9940	6	69	0.2783	0.9278	3.38–108.08	94.02
β-damascenone	L-m	0.64	1.20	0.9991	8	121	0.0120	0.0402	1.01–128.90	95.84
geraniol	L-m	4.08	13.90	0.9976	8	69	0.0241	0.0804	2.39–305.28	94.17
E-geranylacetone	L-m	0.39	0.80	0.9975	7	69	0.0220	0.0734	1.94–124.28	106.8
β-ionone	L-m	0.31	2.00	0.9980	8	177	0.0016	0.0054	0.11–14.08	101.87
E-nerolidol	L-m	0.50	–5.00	0.9944	8	69	0.0063	0.0209	2.28–291.67	91.48
α-ionone	L-m	0.41	–1.00	0.9981	7	121	0.0076	0.0253	2.04–193.30	102.47
α-cedrol	L-m	0.54	33.00	0.9994	6	150	0.0055	0.0185	3.59–114.89	99.82
farnesol	L-m	0.84	19.00	0.9997	9	69	0.0148	0.0493	4.10–1049.79	82.03
β-eudesmol	L-m	2.50	–1.00	0.9964	8	59	0.4045	1.3483	2.04–261.12	118.07
globulol	L-m	2.01	8.43	0.9971	7	95	0.0991	0.3302	2.71–173.44	93.46
α-terpineol	L-m	3.49	6.76	0.9991	6	95	0.1038	0.3460	3.37–107.81	95.47

^aIS: internal standard, L-m: L-menthol, L-ma: L-menthyl acetate;

^bSlo: slope;

^cInt: intercept;

^dNumber of points in the calibration curve;

^eQuant: quantitative of m/z;

^fLOD: limit of detection;

^gLOQ: limit of quantification.

TABLE 4 Concentrations of terpenes in Moutai liquor and other aroma-type Chinese liquors (µg/L; n = 3)

No.	Terpenes	Ave. ± SD
		Moutai	Sauce-1#	Sauce-2#	Light-1#	Strong-1#	Strong-2#	Strong-3#	Strong-4#	Mixed-1#	Mixed-2#	LBG
C1	d-limonene	7.04 ± 1.23^b	6.92 ± 1.71^b	3.30 ± 1.01^d	4.83 ± 0.30^c	ND^e	ND^e	ND^e	ND^e	ND^e	2.28 ± 0.14^d	9.03±0.23^a
C2	citral	24.97 ± 1.46^a	16.47 ± 1.57^c	21.14 ± 2.29^b	25.18 ± 1.58^a	ND^d	ND^d	ND^d	ND^d	ND^d	ND^d	19.36±1.17^b
C3	linalool	32.03 ± 2.03^a	26.51 ± 2.37^b	26.04 ± 1.87^b	14.14 ± 1.26^d	15.32 ± 2.52^d	12.41 ± 2.81^d	6.09 ± 0.19^e	22.56 ± 0.03^c	15.38 ± 1.71^d	15.26 ± 1.71^d	16.91±1.56^d
C4	nerol	6.81 ± 0.15^b	3.88 ± 0.31^d	8.61 ± 0.18^a	4.37 ± 0.27^c	4.75 ± 0.47^c	1.87 ± 0.06^f	ND^g	ND^g	3.07 ± 0.33^e	ND^g	ND^g
C5	terpinen-4-ol	<QL	<QL	ND	<QL	ND	ND	ND	ND	ND	ND	ND
C6	α-terpineol	26.19 ± 2.5^a	15.75 ± 1.77^e	12.74 ± 0.37^f	24.09 ± 1.54^ab	17.21 ± 1.12^de	19.47 ± 1.08^cd	12.18 ± 1.16^f	18.12 ± 1.24^d	23.57 ± 2.02^ab	22.08 ± 2.72^bc	14.97±1.46^ef
C7	β-citronellol	15.96 ± 1.47^a	7.11 ± 0.11^c	10.21 ± 2.06^b	4.15 ± 0.37^d	ND^e	ND^e	ND^e	ND^e	ND^e	ND^e	ND^e
C8	geraniol	7.77 ± 1.09^b	5.08 ± 0.20^d	9.56 ± 0.72^a	6.41 ± 0.16^c	ND^e	ND^e	ND^e	ND^e	ND^e	ND^e	ND^e
C9	α-cedrene	32.71 ± 2.15^a	15.81 ± 1.54^b	10.72 ± 1.48^c	8.24 ± 1.06^cd	9.03 ± 1.10^c	10.54 ± 0.71^c	6.60 ± 0.99^d	9.31 ± 1.24^c	9.12 ± 0.69^c	9.39 ± 1.94^c	10.87±1.61^c
C10	β-caryophyllene	21.68 ± 2.73^d	6.06 ± 1.08^h	28.59 ± 1.39^c	71.11 ± 3.38^b	9.82 ± 0.62^g	18.59 ± 1.44^de	7.93 ± 1.04^gh	9.43 ± 0.74^g	17.75 ± 0.88^e	13.41 ± 1.52^f	140.11±4.82^a
C11	α-cedrol	13.14 ± 1.13^a	6.15 ± 1.01^cd	10.42 ± 1.22^b	4.26 ± 0.30^ef	4.28 ± 0.41^ef	5.37 ± 0.50^de	3.95 ± 0.87^f	5.21 ± 0.38^de	4.67 ± 0.18^ef	6.96 ± 0.96^c	4.77±0.45^e
C12	calarene*	3.52 ± 0.06^b	3.43 ± 0.07^bc	1.33 ± 0.07^g	3.26 ± 0.30^cd	3.19 ± 0.08^de	3.92 ± 0.17^a	2.39 ± 0.09^f	3.53 ± 0.06^b	2.63 ± 0.11^f	2.99 ± 0.14^e	4.05±0.17^a
C13	γ-muurolene*	3.82 ± 0.01^e	6.09 ± 0.28^b	4.35 ± 0.16^d	3.88 ± 0.23^e	3.55 ± 0.20^ef	4.96 ± 0.07^c	3.34 ± 0.04^f	3.59 ± 0.49^ef	3.55 ± 0.03^e	5.84 ± 0.23^b	8.27±0.13^a
C14	α-selinene*	6.81 ± 0.12^a	ND^c	3.11 ± 0.14^b	3.04 ± 0.16^b	2.96 ± 0.55^b	3.05 ± 0.13^b	ND^c	2.94 ± 0.16^b	ND^c	ND^c	ND^c
C15	α-muurolene*	3.85 ± 0.57^def	4.27 ± 0.45^d	3.97 ± 0.44^de	3.57 ± 0.04^ef	4.29 ± 0.13^d	4.94 ± 0.55^c	2.59 ± 0.08^h	5.76 ± 0.23^b	3.32 ± 0.33^f	3.44 ± 0.24^ef	8.07±0.30^a
C16	eremophilene*	1.02 ± 0.01^a	0.95 ± 0.06^a	0.97 ± 0.04^a	0.93 ± 0.01^b	ND^d	ND^d	ND^d	ND^d	0.79 ± 0.02^c	ND^d	ND^d
C17	β-cedrene	4.03 ± 0.30^ab	4.27 ± 0.33^a	3.78 ± 0.51^b	ND^f	ND^f	3.91 ± 0.16^ab	2.57 ± 0.27^e	3.56 ± 0.38^bc	2.97 ± 0.06^de	3.32 ± 0.33^cd	ND^f
C18	γ-elemene*	10.33 ± 0.98^c	10.17 ± 1.82^c	9.03 ± 0.95^c	ND^g	12.04 ± 1.10^b	6.72 ± 0.61^d	2.49 ± 0.11^f	13.60 ± 0.14^a	4.17 ± 0.07^e	3.23 ± 0.10^ef	ND^g
C19	alloaromadendrene	3.86 ± 0.14^d	5.58 ± 0.13^b	4.53 ± 0.16^c	3.24 ± 0.20^e	3.33 ± 0.24^e	3.85 ± 0.07^d	2.55 ± 0.01^f	3.26 ± 0.17^e	2.77 ± 0.13^f	3.31 ± 0.21^e	6.66±0.08^a
C20	β-bisabolene*	3.91 ± 0.21^d	4.88 ± 0.07^b	4.42 ± 0.44^c	ND^g	3.70 ± 0.08^d	3.83 ± 0.20^d	2.49 ± 0.48^f	3.86 ± 0.28^d	2.82 ± 0.30^ef	3.19 ± 0.14^e	6.73±0.20^a
C21	α-chamigrene*	14.87 ± 1.73^b	13.66 ± 2.45^b	26.87 ± 1.03^a	3.71 ± 0.51^de	5.31 ± 0.42^cd	6.01 ± 0.45^c	2.35 ± 0.99^e	3.98 ± 0.10^de	4.14 ± 0.34^d	4.08 ± 0.18^de	7.16±0.08^c
C22	globulol	4.67 ± 0.37^b	18.25 ± 0.20^a	3.88 ± 0.16^c	ND^e	ND^e	ND^e	ND^e	ND^e	3.16 ± 0.04^d	4.41 ± 0.38^b	ND^e
C23	α-cadinol*	4.32 ± 0.33^bc	4.62 ± 0.13^b	3.97 ± 0.54^c	4.33 ± 0.17^b	3.74 ± 0.78^cd	3.86 ± 0.20^c	3.18 ± 0.48^d	3.80 ± 0.01^c	6.12 ± 0.24^a	4.30 ± 0.17^bc	6.12±0.06^a
C24	β-eudesmol	3.73 ± 0.38^a	<QL^d	<QL^d	<QL^d	ND^d	ND^d	<QL^d	ND^d	2.12 ± 0.17^c	<QL^d	2.70±0.28^b
C25	longifolene*	7.14 ± 0.20^b	4.07 ± 0.17^e	4.29 ± 0.73^de	6.75 ± 0.21^b	4.01 ± 0.76^e	4.76 ± 0.07^cd	3.26 ± 0.24^f	3.99 ± 0.20^e	4.76 ± 0.07^cd	5.10 ± 0.04^c	9.54±0.48^a
C26	α-gurjunene	6.50 ± 0.30^a	ND^d	ND^d	3.80 ± 0.72^b	ND^d	2.93 ± 0.52^c	ND^d	ND^d	ND^d	ND^d	6.60±0.03^a
C27	isoledene*	3.41 ± 0.44^b	1.49 ± 0.72^d	2.73 ± 0.38^c	2.71 ± 0.41^c	ND^e	ND^e	ND^e	ND^e	ND^e	ND^e	5.01±0.01^a
C28	(+)-aromadendrene	3.14 ± 0.23^b	3.21 ± 0.65^b	3.02 ± 0.64^b	3.30 ± 0.23^b	ND^c	2.97 ± 0.13^b	ND^c	3.01 ± 0.23^b	ND^c	3.06 ± 0.18^b	4.74±0.16^a
C29	cis-thujopsene	3.86 ± 0.75^cd	7.54 ± 0.01^a	4.16 ± 0.67^c	3.24 ± 0.49^de	3.30 ± 0.42^de	3.85 ± 0.17^cd	2.45 ± 0.18^f	3.22 ± 0.27^de	2.66 ± 0.14^ef	ND^g	6.66±0.71^b
C30	β-guaiene*	3.60 ± 0.33^b	6.89 ± 0.30^a	3.69 ± 0.78^b	3.38 ± 0.55^bc	3.34 ± 0.04^bc	3.37 ± 0.69^bc	ND^e	2.60 ± 0.40^d	2.75 ± 0.04^cd	3.19 ± 0.37^bcd	6.23±0.31^a
C31	δ-cadinene*	10.43 ± 0.30^b	3.23 ± 0.27^fg	3.50 ± 0.23^ef	4.34 ± 0.24^cd	4.05 ± 0.08^de	4.91 ± 0.07^c	2.64 ± 0.28^g	3.43 ± 0.41e^f	3.79 ± 0.04^def	3.16 ± 0.21^fg	13.53±1.21^a
C32	calamenene*	4.47 ± 0.98^e	6.58 ± 0.03^c	5.29 ± 0.62^de	4.51 ± 1.19^e	8.47 ± 0.16^b	9.12 ± 0.41^b	4.87 ± 0.57^e	6.02 ± 0.14^cd	6.06 ± 0.25^cd	4.75 ± 0.45^e	14.01±0.42^a
C33	α-calacorene^e	7.60 ± 0.17^d	6.99 ± 0.04^e	9.05 ± 0.47^c	8.53 ± 0.23^c	11.44 ± 0.25^b	11.27 ± 0.10^b	5.18 ± 0.20^f	7.96 ± 0.47^d	8.42 ± 0.14^c	6.94 ± 0.24^e	26.55±0.24^a
C34	ledol*	4.42 ± 0.21^d	4.50 ± 0.17^cd	5.18 ± 0.18^bc	5.64 ± 0.41^b	4.20 ± 0.52^d	5.75 ± 0.27^b	2.98 ± 0.24^e	4.45 ± 0.31^d	4.24 ± 0.59^d	3.92 ± 0.14^d	15.65±0.82^a
C35	γ-cadinene*	3.23 ± 0.10^bc	3.52 ± 1.02^bc	3.20 ± 0.64^bc	3.31 ± 0.06^bc	3.52 ± 0.45^bc	3.96 ± 0.23^b	2.41 ± 0.34^d	3.22 ± 0.69^bc	2.78 ± 0.03^d	3.16 ± 0.25^c	5.27±0.31^a
C36	α-bergamotene*	11.96 ± 0.06^b	17.52 ± 0.40^a	17.68 ± 1.2^a	3.90 ± 0.25^e	5.82 ± 0.30^d	5.21 ± 1.03^de	2.99 ± 0.24^e	4.38 ± 1.07^de	3.80 ± 1.02^e	3.98 ± 1.40^e	9.87±0.91^c
C37	E-nerolidol	50.66 ± 3.72^a	11.05 ± 1.74^d	24.50 ± 0.07^b	4.35 ± 0.86^e	2.92 ± 0.04^ef	4.46 ± 1.11^e	1.43 ± 0.44^f	10.82 ± 0.68^d	10.19 ± 0.30^d	21.11 ± 1.10^c	20.97±0.20^c
C38	α-ionone	4.06 ± 0.35^ab	3.82 ± 0.58^b	4.32 ± 0.31^a	3.85 ± 0.03^ab	<QL^d	<QL^d	ND^d	ND^d	3.72 ± 0.47^b	4.06 ± 0.28^ab	3.31±0.27^c
C39	isolongifolol*	4.44 ± 0.08^cd	4.07 ± 0.37^de	4.29 ± 0.52^cd	6.75 ± 0.23^b	4.01 ± 0.23^de	4.76 ± 0.17^cd	3.26 ± 0.12^e	3.99 ± 0.33^de	4.76 ± 0.21^cd	5.10 ± 0.87^c	9.54±1.48^a
C40	isocaryophillene*	5.58 ± 0.82^bc	5.02 ± 0.90^cd	4.88 ± 0.43^cd	6.31 ± 0.41^b	3.61 ± 0.18^f	4.45 ± 0.27^de	3.33 ± 0.03^f	3.89 ± 0.44^ef	4.06 ± 0.04^ef	4.39 ± 0.20^de	13.07±0.08^a
C41	farnesol	33.67 ± 1.95^a	11.26 ± 1.56^e	20.00 ± 1.15^c	10.36 ± 0.27^ef	5.48 ± 1.23^hi	6.84 ± 0.10^gh	4.37 ± 1.24^i	7.45 ± 1.92^gh	8.32 ± 0.91^fg	15.61 ± 1.40^d	27.27±1.32^b
C42	theaspirane	<QL	<QL	<QL	0.82 ± 0.01	ND	ND	ND	ND	ND	ND	<QL
C43	isophorone	13.99 ± 1.43^a	5.73 ± 1.47^d	12.09 ± 1.06^b	8.33 ± 0.98^c	ND^e	6.17 ± 0.13^d	ND^e	ND^e	ND^e	ND^e	6.24±0.57^d
C44	E-geranylacetone	77.99 ± 2.93^a	20.47 ± 1.53^d	34.90 ± 2.47^b	7.97 ± 1.16^f	16.72 ± 1.00^e	13.70 ± 1.32^e	5.25 ± 0.55^f	21.15 ± 2.60^d	18.25 ± 0.64^de	20.85 ± 1.58^d	28.74±2.76^c
C45	β-ionone	1.73 ± 0.18^b	0.49 ± 0.13^ef	1.47 ± 0.16^c	1.27 ± 0.01^d	0.51 ± 0.14^ef	0.40 ± 0.01^fg	0.30 ± 0.01^g	0.64 ± 0.04^e	2.20 ± 0.03^a	1.54 ± 0.05^c	1.38±0.13^cd
C46	β-damascenone	11.83 ± 0.34^ab	4.59 ± 0.20^f	12.32 ± 0.81^a	9.92 ± 0.25^c	7.64 ± 0.54^d	6.64 ± 0.34^e	4.24 ± 0.55^f	8.05 ± 0.45^d	7.95 ± 0.01^d	7.78 ± 0.52^d	10.51±0.99^bc
monoterpenes		120.77	81.72	91.60	83.17	37.28	33.75	18.27	40.68	42.02	39.62	60.27
sesquiterpenes		304.44	204.95	239.72	194.60	129.41	158.16	81.60	140.27	140.41	155.40	405.54
C13-norisoprenoids		105.54	31.28	60.78	28.31	24.87	26.91	9.79	29.84	28.40	30.17	46.87
total concentrations		530.75	317.95	392.10	306.08	191.56	218.82	109.66	210.79	210.83	225.19	512.68

No.: number of compounds; Ave: average concentration; SD: standard deviation, three replicates for each of the liquor; ND: not detected; <QL: below quantification limit;

*Terpenes were semi-quantified by using the slope and intercept of α-cedrene;

^{a,b,c,d,e,f,g,h,i}Different letters in the same row denote significant differences (p < 0.05), and same letter in the same row denote no significant differences (p > 0.05).

TABLE 5 OAVs^a of terpenes in Moutai liquor and other aroma-type Chinese liquors

Terpenes	OAVs
	Odor^b	Thr (µg/L)^c	Moutai	Sauce-1#	Sauce-2#	Light-1#	Strong-1#	Strong-2#	Strong-3#	Strong-4#	Mixed-1#	Mixed-2#	LBG
β-damascenone	floral	0.12^d	98	38	103	83	64	55	35	67	66	65	88
β-ionone	violet	1.3^e	1.3	<1	1.1	1.0	<1	<1	<1	<1	1.7	1.2	1.1
α-ionone	violet	1.8^e	2.3	2.1	2.4	2.1	<1	<1	<1	<1	2.1	2.3	1.8
citral	lemon	3^e	8.3	5.5	7.0	8.4	<1	<1	<1	<1	<1	<1	6.5
linalool	floral	13.1^e	2.4	2.0	2.0	1.1	<1	<1	<1	1.7	1.2	1.2	1.3
d-limonene	lemon	41^e	<1	<1	<1	<1	<1	<1	<1	<1	<1	<1	<1
β-citronellol	floral	300^e	<1	<1	<1	<1	<1	<1	<1	<1	<1	<1	<1
geraniol	floral	120^e	<1	<1	<1	<1	<1	<1	<1	<1	<1	<1	<1
E-geranylacetone	floral	267^e	<1	<1	<1	<1	<1	<1	<1	<1	<1	<1	<1
nerol	floral	130 ^e	<1	<1	<1	<1	<1	<1	<1	<1	<1	<1	<1
terpinen-4-ol	herbal	940^e	<1	<1	<1	<1	<1	<1	<1	<1	<1	<1	<1
α-terpineol	floral	680^e	<1	<1	<1	<1	<1	<1	<1	<1	<1	<1	<1
β-caryophyllene	woody	130^e	<1	<1	<1	1	<1	<1	<1	<1	<1	<1	1.0
E-nerolidol	floral	99^e	<1	<1	<1	<1	<1	<1	<1	<1	<1	<1	<1
theaspirane	woody	9.2^e	<1	<1	<1	<1	<1	<1	<1	<1	<1	<1	<1
cedrol	woody	7300^e	<1	<1	<1	<1	<1	<1	<1	<1	<1	<1	<1
α-cedrene	woody	6500^e	<1	<1	<1	<1	<1	<1	<1	<1	<1	<1	<1

^aOAVs: odor activity values;

^bOdor: aroma descriptors from the standards;

^cThr: odor threshold was selected from literature;

^dThresholds was determined in 46% volume hydroalcoholic solution (Gao et al., 2014);

^eThresholds was determined in 46% volume hydroalcoholic solution.

FIGURE 3 Heat map analysis of terpenes in different aroma type Chinese liquors.