Effect of Microwave Precooking and Freeze-Drying on the Quality of the Germinated Brown Rice

Table 4

Relative percentage content of important flavor compounds in brown rice.

Number	Compounds	Retention time	Smell characteristics	Relative percentage content/%
				UBR	TBR
	Aldehydes
A1	Pentanal	9.12	Fruity flavor	—	0.52
A2	Hexanal	10.23	Grassy flavor	0.62	0.16
A3	Heptanal	14.44	Fruity flavor	0.44	0.6
A4	Nonanal	17.846	Citrus flavor	0.16	0.32
A5	Decanal	20.36	Citrus flavor	0.35	0.48
	Alcohols
B1	Ethanol	6.78	Alcohol flavor	—	0.18
B2	1-Butanol	3.85		3.92	4.36
B3	2,3-Butanediol	11.06		2.65	6.32
B4	1-Hexanol,2-ethyl-	19.06	Fruity flavor	0.77	1.38
B5	1-Hexanol	13.26	Fruity flavor	0.47	0.69
B6	1-Hexanol,2-ethyl-	19.06	Fruity flavor	0.28	—
	Terpenes
C1	2,4-Dimethyl-1-heptene	12.49		0.4	0.69
C2	Alpha-Pinene	14.65	Pine terpene flavor	1.32	2.36
C3	D-limonene	19.34	Lemon flavor	—	0.27
	Esters
D1	Ethyl acetate	7.91	Fruity flavor	—	0.26
D2	Acetic acid, butyl ester	9.63	Fruity flavor	—	0.62
	Arenes
E1	Toluene	10.42		1.32	1.54
E2	p-Xylene	13.56		—	0.58
	Ketone
F1	2-Heptanone	35.32	Flower flavor	0.44	0.86
F2	Acetophenone	46.25	Fruity flavor	0.23	0.89

Note: (1) The result of relative percentage content is the ratio of material peak area to total peak area; (2) —: not detected.