Variations in Physicochemical Properties of Chinese Fenjiu During Storage and High-Gravity Technology of Liquor Aging

Figures & data

Figure 1 Schematic diagram of multistage-spraying rotating packed bed (1: rotating packed bed; 2: shell; 3: liquid distributor; 4: spraying area; 5: liquid inlet; 6: motor; 7: gas outlet; 8: gas inlets; 9: liquid outlet; 10: trap; 11: liquid heater; 12: liquid flow controller; 13: gas heater; 14: gas flow controller; 15: gas thermometer; 16: gas valve; 17: pump; 18: liquid thermometer; 19: pressure gauge; 20: liquid valve; 21: liquid storage tank; 22: liquid pipeline; 23: gas pipeline; 24: condensation system).

Figure 2 Total ion chromatogram of Fenjiu (1: acetaldehyde; 2: isobutylaldehyde; 3: ethyl formate; 4: ethyl acetate+acetal; 5: ethanol; 6: 2-butanol; 7: n-propanol; 8: 1,1-diethoxy isopentane; 9: isobutanol; 10: isoamyl acetate; 11: ethyl valerate; 12: butanol; 13: isoamyl alcohol; 14: ethyl caproate; 15: n-pentanol; 16: 3-methyl-3-buten-1-ol; 17: unknown; 18: 1,1,3-triethoxy-propane; 19: ethyl heptanoate; 20: 3-hydroxy butanone; 21: anisole; 22: ethyl lactate; 23: hexanol; 24: ethyl caprylate; 25: 2-hydroxy-3-methyl-butayric acid ethyl ester; 26: 1,2-propanediol; 27: heptanol; 28: acetic acid; 29: furfural; 30: benzaldehyde; 31: propionic acid; 32: 2,3-butanediol(levo); 33: isobutyric acid; 34: 2,3-butanediol(meso); 35: ethyl caprate; 36: butyric acid; 37: γ-butyrolactone; 38: isovaleric acid; 39: diethyl succinate; 40: 2,2-diethoxy-phenylethane; 41: unknown; 42: naphthalene; 43: n-pentanoic acid; 44: ethyl phenylacetate; 45: 1-nitro-4-vinylbenzene; 46: phenyl ethyl acetate; 47: ethyl laurate; 48: hexanoic acid; 49: unknown; 50: 1-methylnaphthalene; 51: benzoic acid; 52: diisobutyl succinate; 53: β-phenylethyl alcohol; 54: 1,5-dimethyl naphthalene; 55: enanthic acid; 56: 1,2- dimethyl naphthalene; 57: ethyl myristate; 58: 4-pentyl-γ- butyrolactone; 59: 2-methyl-diphenyl; 60: diisobutyl adipate; 61: ethyl pentadecanoate; 62: 4,4'-dimethoxy-diphenylmethane; 63: ethyl palmitate; 64: ethyl 11-hexadecenoate; 65: ethyl 9-hexadecenoate; 66: propanetriol; 67: ethyl stearate; 68: ethyl oleate; 69: ethyl linoleate; 70: diisobutyl phthalate; 71: octadeca-9,12,15-trienoate; 72: unknown; 73: dibutyl phthalate).

Table 1  Aroma components of Fenjiu under different ages as detected by HS/GC/MS

R.T./min	New brewed liquor	2-Year aged liquor	10-Year aged liquor
1.547	2-methyl piperazine	ND	ND
1.611	Acetaldehyde	Acetaldehyde	Acetaldehyde
1.948	Ethyl formate	Ethyl formate	Ethyl formate
2.002	Isobutyl aldehyde	Isobutyl aldehyde	Isobutyl aldehyde
2.287	Ethyl acetate	Ethyl acetate	Ethyl acetate
2.626	Isovaleric aldehyde	Isovaleric aldehyde	Isovaleric aldehyde
2.679	DL-3-amino-n-butyric acid	ND	ND
2.882	Ethanol	Ethanol	Ethanol
3.049	Ethyl propionate	Ethyl propionate	Ethyl propionate
3.271	1,1-Diethoxy isobutane	1,1-Diethoxy isobutane	1,1-Diethoxy isobutane
3.842	Isobutyl acetate	Isobutyl acetate	Isobutyl acetate
5.069	1,1-Diethoxy isopentane	1,1-Diethoxy isopentane	1,1-Diethoxy isopentane
5.355	n-Propanol	n-Propanol	n-Propanol
6.296	Isobutyl alcohol	Isobutyl alcohol	Isobutyl alcohol
6.423	Isoamyl acetate	Isoamyl acetate	Isoamyl acetate
9.511	5-Methylthiazole	ND	ND
10.220	2-methyl-1-butanol	2-methyl-1-butanol	2-methyl-1-butanol
10.452	Isoamyl alcohol	Isoamyl alcohol	Isoamyl alcohol
15.231	Ethyl lactate	Ethyl lactate	Ethyl lactate
18.909	Acetic acid	Acetic acid	Acetic acid
22.192	Dihexyl sulfite	ND	ND
24.191	γ- butyrolactone	γ-butyrolactone	γ-butyrolactone
25.852	2-Methyl azetidine	ND	ND
26.812	Ethyl octanoate	Ethyl octanoate	Ethyl octanoate
28.729	Methoxy-benzaldoxime	ND	ND
30.473	Ethyl pelargonate	Ethyl pelargonate	Ethyl pelargonate
34.319	Ethyl caprate	Ethyl caprate	Ethyl caprate
41.455	Ethyl undecanoate	Ethyl undecanoate	Ethyl undecanoate
ND: not detected. These compounds were identified by the mass spectra data.

Table 2  Aroma compound contents of Fenjiu under different ages and the liquor treated by HGRPB (mg/L)

Composition	0 ^a	0.5 ^a	2 ^a	5 ^a	10 ^a	16 ^a	20 ^a	25 ^a	30 ^a	Treated ^b
Acetaldehyde	192.2 ± 3.43	155.5 ± 2.57	178.2 ± 1.25	175.6 ± 5.56	161.0 ± 0.50	153.9 ± 3.12	129.4 ± 2.81	102.7 ± 3.79	84.0 ± 0.51	162.1 ± 2.36
Isobutyl aldehyde	5.19 ± 0.52	4.98 ± 0.41	6.39 ± 0.34	1.94 ± 0.01	2.54 ± 0.10	3.11 ± 0.12	2.69 ± 0.07	2.18 ± 0.18	1.03 ± 0.09	5.06 ± 0.31
Ethyl formate	8.93 ± 0.07	8.79 ± 0.11	7.42 ± 0.14	7.17 ± 0.01	3.28 ± 0.25	2.46 ± 0.04	1.95 ± 0.02	1.55 ± 0.06	1.38 ± 0.06	7.46 ± 0.08
Ethyl acetate+Acetal	2627.9 ± 1.83	2498.6 ± 39.1	2284.8 ± 69.9	3502.5 ± 1.12	1674.4 ± 2.23	2570.7 ± 71.2	1277.5 ± 67.0	1267.7 ± 29.3	993.5 ± 45.3	2445.3 ± 17.9
Methanol ^c	161.5 ± 3.23	149.2 ± 1.83	142.7 ± 0.77	145.8 ± 1.77	132.5 ± 3.72	126.1 ± 1.57	109.4 ± 1.82	120.4 ± 5.05	93.4 ± 0.71	147. 2 ± 2.74
Isovaleric aldehyde ^c	9.48 ± 0.35	9.18 ± 0.09	10.0 ± 0.01	9.81 ± 0.63	10.9 ± 0.37	7.62 ± 0.048	6.51 ± 1.33	7.04 ± 1.62	4.06 ± 0.23	8.11 ± 0.39
2-Butanol	1.46 ± 0.03	1.24 ± 0.07	1.12 ± 0.08	1.20 ± 0.16	1.87 ± 0.14	1.09 ± 0.01	1.52 ± 0.13	1.85 ± 0.19	1.16 ± 0.09	1.06 ± 0.04
n-Propanol	133.9 ± 3.62	143.2 ± 2.07	124.4 ± 2.51	122.7 ± 2.90	166.1 ± 3.49	162.0 ± 3.32	147.3 ± 3.82	156.4 ± 3.60	177.3 ± 1.77	137.6 ± 2.58
1,1-Diethoxy isopentane	6.57 ± 0.36	6.66 ± 0.06	7.84 ± 0.28	7.31 ± 0.06	4.98 ± 0.18	9.72 ± 0.20	13.3 ± 0.13	18.7 ± 0.35	14.4 ± 0.07	6. 83 ± 0.97
Isobutanol	104.9 ± 1.85	152.0 ± 0.70	150.7 ± 1.99	172.7 ± 3.21	178.0 ± 4.06	175.2 ± 3.92	142.4 ± 2.94	205.6 ± 4.27	220.0 ± 1.87	143.7 ± 1.63
Isoamyl acetate	9.98 ± 0.42	4.97 ± 0.06	6.31 ± 0.36	7.55 ± 0.19	6.16 ± 0.06	4.93 ± 0.52	1.90 ± 0.04	1.49 ± 0.13	1.85 ± 0.04	8. 13 ± 0.31
Butanol	5.57 ± 0.28	4.59 ± 0.13	5.56 ± 0.37	5.83 ± 0.03	4.67 ± 0.43	4.33 ± 0.22	4.27 ± 0.25	6.29 ± 0.35	5.42 ± 0.11	5.42 ± 0.17
Isoamyl alcohol	416.7 ± 17.6	394.4 ± 13.8	391.5 ± 14.9	457.6 ± 20.5	532.8 ± 32.1	522.9 ± 27.0	418.6 ± 17.1	628.3 ± 36.7	586.1 ± 13.8	396.4 ± 12.9
Ethyl caproate	8.05 ± 0.12	5.06 ± 0.33	6.56 ± 0.19	8.99 ± 0.28	4.64 ± 0.26	4.82 ± 0.33	3.61 ± 0.07	4.34 ± 0.17	3.12 ± 0.28	6.17 ± 0.07
n-Pentanol	1.68 ± 0.12	1.84 ± 0.03	1.48 ± 0.11	2.19 ± 0.19	1.72 ± 0.26	1.56 ± 0.12	2.07 ± 0.05	2.01 ± 0.02	2.14 ± 0.13	1.48 ± 0.15
3-Hydroxy butanone	14.5 ± 0.36	15.6 ± 0.05	16.5 ± 0.11	18.4 ± 0.26	24.7 ± 0.37	25.8 ± 0.49	29.9 ± 0.70	34.3 ± 1.66	35.6 ± 0.79	17.7 ± 0.35
Ethyl lactate	4250.6 ± 33.6	4115.2 ± 51.5	4173.1 ± 62.5	3063.1 ± 89.2	3610.0 ± 14.1	3357.5 ± 15.2	3103.9 ± 31.0	2681.9 ± 15.4	2470.0 ± 25.3	3999.3 ± 23.4
Ethyl caprylate	7.71 ± 0.59	6.89 ± 0.56	5.73 ± 0.31	7.39 ± 0.15	6.40 ± 0.37	5.96 ± 0.29	2.52 ± 0.26	3.91 ± 0.31	2.60 ± 0.09	7.15 ± 0.13
Acetic acid	993.4 ± 60.6	871.3 ± 18.6	966.2 ± 27.5	1371.1 ± 47.2	1233.9 ± 31.3	1348.1 ± 22.3	1313.7 ± 17.2	1443.2 ± 41.5	1484.9 ± 9.78	1604.5 ± 23.8
Furfural	6.05 ± 0.19	4.96 ± 0.38	4.74 ± 0.08	4.22 ± 0.09	2.71 ± 0.23	2.98 ± 0.06	2.35 ± 0.22	2.19 ± 0.01	3.16 ± 0.26	4.08 ± 0.21
Benzaldehyde	17.4 ± 0.69	22.2 ± 0.24	24.1 ± 1.85	24.9 ± 0.24	16.1 ± 1.09	13.4 ± 0.82	11.9 ± 0.04	15.7 ± 1.11	19.8 ± 0.83	15.0 ± 0.83
2,3-Butanediol(levo)	18.9 ± 0.61	29.9 ± 1.27	22.1 ± 0.72	22.7 ± 0.06	13.7 ± 0.04	15.1 ± 1.12	12.3 ± 0.58	8.34 ± 0.27	6.75 ± 0.59	19.6 ± 1.36
Ethyl caprate	5.30 ± 0.33	5.64 ± 0.15	6.13 ± 0.21	5.80 ± 0.30	5.41 ± 0.72	4.60 ± 0.32	3.59 ± 0.17	5.57 ± 0.19	5.90 ± 0.25	6.09 ± 0.42
Butyric acid	6.47 ± 0.12	6.41 ± 0.41	7.67 ± 0.16	7.68 ± 0.25	10.2 ± 0.39	11.6 ± 0.44	12.6 ± 0.51	15.8 ± 0.11	19.5 ± 0.10	6.95 ± 0.52
Diethyl succinate	10.6 ± 0.14	13.7 ± 0.15	14.4 ± 0.79	16.2 ± 0.22	7.86 ± 0.68	6.65 ± 0.18	7.64 ± 0.23	13.4 ± 0.64	11.9 ± 0.30	12.8 ± 1.37
Hexanoic acid	2.82 ± 0.15	2.37 ± 0.04	2.56 ± 0.14	2.78 ± 0.16	3.15 ± 0.11	3.43 ± 0.17	3.73 ± 0.14	4.36 ± 0.19	5.11 ± 0.16	2.44 ± 0.03
β-Phenylethyl alcohol	7.42 ± 0.31	6.92 ± 0.11	7.70 ± 0.24	7.94 ± 0.16	11.1 ± 0.55	11.6 ± 0.47	13.5 ± 0.40	12.6 ± 0.24	16.0 ± 0.54	8. 16 ± 0.72
Ethyl palmitate	2.74 ± 0.14	1.70 ± 0.09	1.06 ± 0.06	1.62 ± 0.17	1.68 ± 0.16	1.62 ± 0.09	0.72 ± 0.02	1.24 ± 0.11	1.52 ± 0.21	1.03 ± 0.09
Propanetriol	62.9 ± 2.91	38.6 ± 0.79	23.2 ± 1.61	49.2 ± 1.57	47.4 ± 0.61	44.4 ± 2.03	27.9 ± 2.76	36.2 ± 1.33	39.9 ± 0.99	46.8 ± 2.7
Ethyl oleate	26.2 ± 1.77	15.7 ± 1.60	13.7 ± 2.21	22.3 ± 1.57	22.7 ± 1.73	22.3 ± 1.55	13.4 ± 0.34	15.1 ± 0.14	15.5 ± 0.96	15.3 ± 2.41
Ethyl linoleate	34.5 ± 2.06	20.7 ± 1.07	23.7 ± 0.73	24.2 ± 0.05	27.2 ± 2.38	31.5 ± 1.39	14.4 ± 0.55	22.0 ± 1.68	20.9 ± 1.67	24.1 ± 2.10
^aTime of storage (years); ^bliquor treated by HGPRB; ^cidentified by coelution with standard volatile compounds.

Table 3  Metal ion contents (mg/L) and electrical conductivities (μs/cm) of Fenjiu under different ages (year)

Liquor age	0	0.5	2	5	10	16	20	25	30	Treated ^a
Electrical conductivity	10.72 ± 0.52	9.55 ± 0.34	11.23 ± 0.12	12.85 ± 0.29	27.20 ± 0.33	35.45 ± 0.82	42.17 ± 0.58	40.59 ± 0.09	43.95 ± 0.17	20.57 ± 0.11
Ca	0.566 ± 0.008	0.681 ± 0.006	0.874 ± 0.006	1.26 ± 0.047	1.59 ± 0.021	2.13 ± 0.035	2.49 ± 0.031	3.05 ± 0.081	4.31 ± 0.015	1.390 ± 0.12
Fe	0.162 ± 0.003	0.189 ± 0.004	0.263 ± 0.007	0.824 ± 0.003	1.12 ± 0.015	1.26 ± 0.021	1.33 ± 0.017	1.39 ± 0.030	1.63 ± 0.036	0.297 ± 0.004
Zn	0.0201 ± 0.0006	0.0372 ± 0.0003	0.0691 ± 0.0005	0.104 ± 0.002	0.183 ± 0.004	0.147 ± 0.004	0.259 ± 0.001	0.327 ± 0.005	0.375 ± 0.006	0.153 ± 0.003
^aLiquor treated by HGPRB.

Table 4  Metal ion contents (mg/L) and electrical conductivities (μs/cm) of liquors stored for one year in vessels made of different materials

Material of vessels	Al	Ca	Cu	Fe	Mg	Zn	Electrical conductivity
Stainless steel	0.287 ± 0.007	0.652 ± 0.014	0.0055 ± 0.0001	0.155 ± 0.003	0.506 ± 0.006	0.0198 ± 0.0004	10.87 ± 0.13
Black pottery	0.753 ± 0.014	1.090 ± 0.040	0.0056 ± 0.0001	0.0783 ± 0.0007	0.761 ± 0.006	0.0277 ± 0.0005	21.43 ± 0.04
Red pottery	1.040 ± 0.025	2.800 ± 0.058	0.0064 ± 0.0002	0.210 ± 0.009	2.160 ± 0.021	0.0393 ± 0.0005	21.72 ± 0.16

Table 5  Organoleptic investigation results of the liquors

Samples	Color (10)	Smell (25)	Taste (50)	Style (15)	Comment	Score
Liquor treated	10 ± 0.0	22.3 ± 0.95	45.1 ± 0.99	14.0 ± 0.67	Colorless transparent, harmonious, tasted clear and sweet	91.4 ± 1.89
New brewed liquor	10 ± 0.0	20.7 ± 0.32	40.6 ± 0.68	13.1 ± 0.74	Colorless transparent, smelly, tasted bitter and acerbity	84.4 ± 0.99
0.5-Year aged liquor	10 ± 0.0	21.5 ± 0.49	41.4 ± 1.06	13.3 ± 0.69	Colorless transparent, a little smelly, tasted a little acerbity	86.2 ± 1.03
2-Year aged liquor	10 ± 0.0	22.6 ± 0.58	44.3 ± 0.73	13.7 ± 1.52	Colorless transparent, harmonious, tasted sweet	90.6 ± 0.85
5-Year aged liquor	10 ± 0.0	23.5 ± 0.21	45.0 ± 0.19	14.4 ± 0.14	Colorless transparent, harmonious, tasted clear and sweet, aged-liquor smell slightly	92.9 ± 0.62