Table 5. Volatile compounds in distilled liquid produced by the solid fermentation

Volatile compound (mg/L)	The number of fermentation times	Sorghum	Corn	Wheat	Barley	Millet
Ethyl acetate	1st	82,750.3±26,549.8a1)	42,353.2±9,912.2b	24,280.7±3,012.9b	21,168.7±4,634.8b	17,678.3±1,709.8b
	2nd	70,910.3±52,378.2	61,845.9±24,632	53,234.4±15,989.5	38,082.8±13,280.4	53,758.1±29,280.8
	3rd	23,902.1±11,120.7	16,002.5±6,101.9	15,118.9±4,129.7	19,348.5±5,705.7	13,734.4±9,851.4
Ethyl butyrate	1st	879±79.5a	665±117bc	675.3±11.9bc	591.3±13.9c	720.9±18.7b
	2nd	1,114.5±186.49bc	1,358.5±412.2ab	960.9±76.8ba	763±126.3c	1,669±105.37a
	3rd	1,976.2±868b	4,473.7±479.5a	2,471.1±768.6b	2,406.3±648.8b	1,772±556.2b
Ethyl caproate	1st	28.3±0.7b	22.1±0.3d	38.2±1.5a	26.1±0.9c	29.9±0.9b
	2nd	19.9±2.9a	19±2.4a	22±3.4a	20.5±3.7a	23.8±5a
	3rd	9.0±8.8	3.1±5.4	7.1±6.2	6.9±6	ND2)
Ethyl lactate	1st	124±27.3a	77.6±14.4bc	92±16.8b	56.1±1.3cd	47.3±3.7d
	2nd	202.4±34.4a	147.3±38.6ab	79.6±18.2c	101.2±34.7bc	204.3±24.7a
	3rd	176.5±62.5	164.3±17.2	117.9±40.7	135.4±25.2	132.3±19.5
Ethyl palmitate	1st	108.5±15.5bc	121.69±8.9ab	126.6±5.6ab	136.1±15.9a	94.6±9.5c
	2nd	126.3±12.3	139.3±4.8	127.3±18.3	122.1±9.535	131.4±42.9
	3rd	43.2±74.9	ND	ND	ND	ND
Acetic acid	1st	394.7±84.6a	197.4±58.3b	118.6±18.1bc	61.6±23.7c	52.2±12.4c
	2nd	1,379.9±1,118.34	579.5±216.6	525.3±227	402.9±116	1,573.5±1,309.4
	3rd	4,671.8±6,374.8	2,540.4±426.2	2,639.7±810	3,288.9±1,230.3	2,882.9±1,656.7
Propionic acid	1st	43.9±5.8a	ND	ND	ND	ND
	2nd	97±10.7b	61.6±29.7b	13.6±236c	ND	180.4±26.5a
	3rd	204.7±101.3b	387.4±102.6ab	525.6±101.8a	632.9±176.9a	549±158.8a
Butyric acid	1st	ND	ND	ND	ND	ND
	2nd	ND	ND	ND	ND	20.8±18.02
	3rd	24.5±21.7	29.1±26.5	79.4±99.3	36.6±4.3	51.6±16.4
Isovaleric acid	1st	37.6±0.6a	35.1±2.6b	38.3±1.4a	N/D	N/D
	2nd	67.9±26.2ab	55.8±32.2ab	32.8±1.3b	37.3±3.1b	89.5±25.5a
	3rd	60.7±19.5	98.6±72.5	98.3±59.7	88.5±8.5	134.1±80.4
Caproic acid	1st	ND	ND	ND	ND	ND
	2nd	45.5±39.4a	ND	ND	ND	ND
	3rd	69.6±2.2	69.83±2.1	69.77±1.3	68.7±0.8	46.2±40.1

Mean±SD (n=3) within each line followed by different letters is significantly different (p<0.05).
Not detected.