Table 2. Chemical composition of the essential oils extracted from Citrus × natsudaidai peels during fruit ripening (only components with S/N > 50)

Classification	Compound name1)	Immaturity	Maturity	Overripe	KI2)
Monoterpene hydrocarbons	α-Pinene	0.57	0.46	0.52	926
	β-Pinene	0.17	0.21	0.21	970
	β-Myrcene	1.17	1.09	1.30	986
	α-Terpinene	0.17	0.10	0.08	1,024
	Cymene	0.15	0.21	0.36	1,033
	D-Limonene	86.44	90.34	90.45	1,041
	β-Ocimene	0.27	0.19	0.23	1,057
	γ-Terpinene	6.32	5.03	4.75	1,068
	Terpinolene	0.67	0.37	0.34	1,089
Oxygenated monoterpenes	Linalool oxide	0.26	0.11	0.12	1,078
	Linalool	0.32	0.17	0.11	1,099
	β-Terpineol	0.41	0.13	0.10	1,146
	Terpinen-4-ol	0.25	0.15	0.11	1,179
	α-Terpineol	2.16	0.77	0.61	1,194
Sesquiterpene hydrocarbons	β-Elemene	-	0.09	0.06	1,395
Oxygenated sesquiterpenes	(+)-Nootkatone	-	-	0.14	1,828
Organic compound	Octanal	0.15	0.04	-	1,003
Unknown compound		0.49	0.52	0.44

Compounds are listed in order of their elution from a VF-5MS column.
Retention index experimentally determined on VF-5MS column with reference to n-alkanes (C₈–C₂₀).
KI: Kovats retention index.