Table 5. Volatile components (mg/L) in the vacuum-distilled soju (abv. 25%) prepared with non steamed rice and various enzyme products

Compounds	White koji	Modified nuruk	Chung-moo PE³⁾	Nurukzyme R400	Sanferm yield	Diazyme X4
Alcohol
1-Propanol (P)	17.45±0.13^b1)2)	7.14±0.12^d	6.47±0.54^d	61.59±0.54^a	16.49±0.18^b	11.35±3.18^c
Isobutanol (B)	138.83±0.81^b	57.17±0.81^f	100.17±0.43^c	72.05±0.26^e	166.09±0.59^a	87.49±6.06^d
1-Butanol	0.43±0.01^bcd	0.89±0.04^b	ND⁴⁾	111.38±0.58^a	0.24±0.01^c	0.64±0.14^bcd
Isoamyl alcohol (A)	485.94±2.71^b	224.10±3.34^d	325.76±1.74^c	198.92±0.61^d	569.00±2.69^a	317.39±41.89^c
Furfuryl alcohol	15.55±0.13^d	39.08±0.85^b	0.74±0.03^e	46.87±0.20^a	0.46±0.08^e	23.58±0.92^c
Phenethyl alcohol	51.60±0.31^a	19.47±0.33^d	26.83±0.18^c	13.91±0.04^e	37.76±0.35^b	20.16±4.35^d
Subtotal	709.85±4.11^b	347.84±5.49^e	459.97±2.41^d	504.73±2.22^c	790.05±3.90^a	460.62±56.53^d
P+B+A	642.22±1.77^b	288.41±4.03^e	432.41±1.63^c	270.97±3.30^d	751.58±2.28^a	416.23±39.01^c
A/P	27.85±0.36^c	31.39±1.00^bc	50.35±4.56^a	3.23±0.09^d	34.51±0.21^b	27.96±4.56^c
A/B	3.50±0.04^ab	3.92±0.01^a	3.25±0.01^bc	2.76±0.03^c	3.43±0.03^ab	3.63±0.73^ab
B/P	7.96±0.01^b	8.01±0.25^b	15.48±1.38^a	1.17±0.01	10.07±0.15^b	7.71±2.96^b
Fatty acid
Butyric acid	6.74±0.04^d	21.77±0.67^b	3.03±0.05^e	61.66±0.25^a	2.45±0.13^e	11.11±0.98^c
Valeric acid	ND	2.22±0.02^a	1.58±0.01^c	1.63±0.01^bc	1.66±0.01^b	1.66±0.07^b
Isovaleric acid	1.73±0.01^e	1.62±0.01^f	16.2±0.01^a	2.02±0.01^c	1.85±0.01^d	2.09±0.03^b
Hexanoic acid	1.32±0.00^b	1.44±0.02^a	ND	ND	1.33±0.02^b	ND
Heptanoic acid	ND	ND	ND	ND	ND	ND
Octanoic acid	1.04±0.01^d	0.97±0.01^d	2.63±0.02^bc	2.26±0.02^c	4.77±0.00^a	2.82±0.57^b
Nonanoic acid	ND	2.90±0.03^a	ND	0.68±0.00^b	ND	ND
Subtotal	10.84±0.06^d	30.92±0.76^b	9.20±0.10^e	68.26±0.28^a	12.06±0.16^d	17.68±1.65^c
Ester
Ethyl acetate	123.61±1.55^b	352.09±4.43^a	75.10±2.45^c	61.01±1.56^d	78.74±0.10^c	57.53±10.74^d
Ethyl butyrate	14.46±0.11^b	6.44±0.10^d	6.27±0.02^d	48.96±0.43^a	14.26±0.14^b	10.08±2.32^c
Isoamyl acetate	8.18±0.05^a	1.93±0.01^cd	2.03±0.02^c	1.28±0.00^e	2.68±0.02^b	1.83±0.23^d
Ethyl succinate	ND	ND	ND	ND	ND	ND
Ethyl hexanoate	0.91±0.01^a	0.91±0.01^a	0.71±0.01^b	0.62±0.02^c	0.72±0.05^b	0.70±0.05^b
Ethyl heptanoate	ND	ND	ND	ND	0.46±0.00^b	0.47±0.01^a
Ethyl lactate	3.30±0.03^d	45.81±0.63^a	2.94±0.06^d	13.37±0.05^b	2.02±0.02^e	11.16±0.31^c
Ethyl octanoate	2.95±0.01^d	2.62±0.03^d	4.55±0.07^b	3.74±0.04^c	8.06±0.07^a	4.55±0.51^b
Ethyl nonanoate	ND	1.68±0.01^a	ND	0.84±0.01^b	ND	0.83±0.01^b
Subtotal	153.40±1.76^b	411.47±5.21^a	91.62±2.64^e	128.98±2.09^c	106.94±0.40^d	87.14±14.18^e
Sulfur
Dimethyl sulfide	0.66±0.01^c	0.61±0.01^c	1.15±0.01^a	1.01±0.02^bc	1.13±0.03^ab	1.01±0.13^abc
Dimethyl disulfide	ND	ND	ND	1.19±0.00	ND	ND
Dimethyl trisulfide	ND	ND	ND	1.01±0.04^b	1.31±0.02^a	1.02±0.01^b
Subtotal	0.66±0.01^e	0.61±0.01^e	1.15±0.01^d	3.21±0.06^a	2.44±0.05^b	2.03±0.13^c
Aldehyde
Furfural	1.43±0.01^b	1.52±0.01^ab	1.56±0.11^ab	1.71±0.11^a	1.70±0.01^a	1.72±0.21^a

All values are mean±SD (n=3).
^a-fMeans with different superscripts in the same row are significantly different at p<0.05 by Duncan’s multiple range test.
Chung-moo PE means Chung-moo purified enzyme.
ND, not detected.
The vacuum-distilled soju (abv. 25%) was prepared by adding water to the distillates, as listed in Table 4.