. 2019 May 6;56(6):2836–2844. doi: 10.1007/s13197-019-03700-1

Table 3.

Relative contents of volatile compounds of freeze-dried Asian pear powder (FDAPP) and hot air-dried Asian pear powder (HDAPP)

No.	Retention time (min)	Volatile compounds	Relative contents (peak area %)
No.	Retention time (min)	Volatile compounds	FDAPP	HDAPP
Alcohols
1	6.26	Ethanol	18.30 ± 0.56^a,*	8.37 ± 0.37^b
2	25.113	4-Hexen-1-ol	3.47 ± 0.15	ND
3	27.649	1-Hexanol	9.01 ± 0.27^a	2.78 ± 0.40^b
4	29.418	3-Hexen-1-ol	2.09 ± 0.07	ND
5	30.794	2-Hexen-1-ol	1.00 ± 0.06^a	0.25 ± 0.03^b
6	40.283	1-Octanol	0.35 ± 0.02^a	0.10 ± 0.01^b
Aldehydes
7	11.446	Hexanal	18.01 ± 1.45^a	5.19 ± 0.31^b
8	18.674	2-Hexenal	9.61 ± 0.03^a	3.34 ± 0.35^b
9	23.285	Octanal	3.90 ± 0.08^a	4.01 ± 0.13^a
10	25.249	2-Heptenal	0.42 ± 0.08^a	0.21 ± 0.02^b
11	29.89	Nonanal	14.01 ± 1.08^a	10.03 ± 1.82^b
12	31.894	2-Octenal	1.00 ± 0.17^a	1.03 ± 0.14^b
13	33.062	Methional	0.42 ± 0.01^b	0.81 ± 0.13^a
14	33.563	Furfural	1.68 ± 0.10^b	30.02 ± 1.42^a
15	36.419	Decanal	1.20 ± 0.09^b	4.19 ± 0.26^a
16	37.029	Benzaldehyde	1.02 ± 0.09^b	1.75 ± 0.12^a
Carboxylic acids and ketones
17	57.175	Propanoic acid	0.27 ± 0.06^a	0.09 ± 0.04^b
18	72.181	Nonanoic acid	0.59 ± 0.03^b	2.39 ± 0.49^a
19	66.133	2,5-Dimethyl-4-hydroxy-3(2H)-furanone	ND	0.28 ± 0.01
Esters
20	16.936	Hexanal, 3-methyl-	0.35 ± 0.03^a	0.19 ± 0.01^b
21	19.785	Furan, 2-pentyl-	1.22 ± 0.11^a	0.23 ± 0.02^b
22	36.113	Ethanone, 1-(2-furanyl)-	ND	0.56 ± 0.05
23	22.44	Acetic acid, hexyl ester	ND	0.24 ± 0.03
24	26.263	5-Hepten-2-one, 6-methyl-	1.72 ± 0.01^a	0.15 ± 0.01^b
25	31.582	2(3H)-Furanone, 5-methyl-	ND	0.41 ± 0.07
26	32.723	Octanoic acid, ethyl ester	ND	0.36 ± 0.04
27	40.157	2-Furancarboxaldehyde, 5-methyl-	ND	1.88 ± 0.18
28	45.742	Benzoic acid, ethyl ester	ND	0.16 ± 0.01
29	74.864	4H-Pyran-4-one, 2,3-dihydro-3,5-dihydroxy-6-methyl-	0.52 ± 0.05^b	17.88 ± 1.53^a
30	75.209	Hexadecanoic acid, ethyl ester	ND	0.76 ± 0.13

*Values are expressed as mean ± standard deviation (SD) of triplicate analysis

^a,bMeans followed by different letters on the same row are significantly different (p < 0.05); ND not detected