Study on the Effects of Processes on Aroma Compounds in Rizhao Green Tea Based on the Gas Chromatography-Ion Mobility Spectrometry

Table 1

Relative content, aroma sensory threshold, and ROAV of volatile substances in tea samples.

Type	Serial number	Name of compound	Relative content^1/%				Aroma sensory threshold^2 (mg/kg)	ROAV
			TL^3	FL	RL	GT
Alcohols (15)	1	2-Butanol					5.1	0.0004
	2	Pentan-1-ol-M					5	0.0018
	3	Pentan-1-ol-D					5	0.0016
	4	n-Hexanol-M					0.7	0.0061
	5	n-Hexanol-D					0.7	0.0025
	6	3-Methyl-1-pentanol					\	\
	7	Heptan-2-ol					0.1	0.0147
	8	(E)-2-Hexen-1-ol-M					\	\
	9	(E)-2-Hexen-1-ol-D					\	\
	10	(Z)-3-Hexen-1-ol					0.2	0.0473
	11	Oct-1-en-3-ol					0.007	0.2
	12	Linalool					0.0038	6.5
	13	2-Furanmethanol					1	0.0105
	14	Linalool oxide-M					\	\
	15	Linalool oxide-D					\	\
Aldehydes (20)	1	Butanal					0.06	0.0800
	2	Pentanal					0.008	7.7
	3	Hexanal-M					0.005	5.6
	4	Hexanal-D					0.005	12
	5	Heptanal-M					0.01	2.4
	6	Heptanal-D					0.01	1.5
	7	Octanal-M					0.0001	100
	8	Octanal-D					0.0001	16
	9	Nonanal					0.015	1.1
	10	2-Methylbutanal					0.001	54
	11	3-Methylbutanal					0.002	13
	12	(E)-2-Pentenal					2.7	0.0042
	13	(E)-Hept-2-enal-M					\	\
	14	(E)-Hept-2-enal-D					\	\
	15	Benzaldehyde-M					0.3	0.0191
	16	Benzaldehyde-D					0.3	0.0071
	17	Benzene acetaldehyde-M					0.009	0.6
	18	Benzene acetaldehyde-D					0.009	0.1
	19	3-Methylthiopropanal-M					0.00004	27
	20	3-Methylthiopropanal-D					0.00004	40
Ketones (13)	1	Acetone					100	0.0013
	2	2-butanone					3	0.0287
	3	3-Hydroxybutan-2-one					0.75	0.0087
	4	2-Pentanone					0.3	0.4
	5	3-Pentanone					\	\
	6	Methyl isobutyl ketone					\	\
	7	2-Hexanone-M					0.09	0.2
	8	2-Hexanone-D					0.09	0.3
	9	2-Heptanone-M					0.2	0.0647
	10	2-Heptanone-D					0.2	0.0193
	11	Methyl-5-hepten-2-one					0.1	0.2
	12	Cyclohexanone-M					\	\
	13	Cyclohexanone-D					\	\
Esters (10)	1	Ethyl formate					6.6	0.0016
	2	Methyl acetate					\	\
	3	Ethyl acetate					0.1	0.0507
	4	Methyl 2-methylbutanoate					0.0002	6.7
	5	Butyl acetate					0.2	0.0093
	6	Methyl hexanoate-M					\	\
	7	Methyl hexanoate-D					\	\
	8	Isoamyl acetate					0.005	0.2
	9	(E)-2-Hexenyl acetate					\	\
	10	Methyl salicylate					0.06	0.0578
Terpenes (2)	1	Alpha-Phellandrene					\	\
	2	(E)-Ocimene					\	\
Oxygen compounds(2)	1	2-Pentyl furan					0.0048	0.7
	2	2-Butoxyethanol					2.6	0.0004

¹ Relative content of compounds in samples are represented as error of mean (). ² “\” represents the threshold values of compounds that were not measured in water. All aroma sensory thresholds were obtained from Van Gemert, L. J. (2011). Compilations of Flavour Threshold Values in Water and Other Media (2nd ed). Tang, E., et al., trans. Beijing, Science Press, 2015.³ The letters represent the significant difference () between different process of Rizhao green tea.