Table 5. Organic acid of whole onion by growth stage (unit: mg/100 g FW)

Growth stage		Oxalic acid	Malic acid	Citric acid	Acetic acid	Total organic acid2)
Whole onion	16 weeks	12.5±0.18a1)	509±0.74b	52.8±0.45c	ND	574±0.27a
	17 weeks	11.3±0.16b	517±0.45a	40.8±0.14g	ND	569±0.15b
	19 weeks	9.79±0.05c	415±0.71c	36.6±0.57h	ND	462±0.26c
	21 weeks	4.91±0.07g	257±0.21f	49.1±0.22e	ND	311±0.10f
	23 weeks	5.26±0.07f	259±0.28e	51.5±0.57d	ND	316±0.18e
	25 weeks	6.62±0.08e	196±0.13g	63.3±0.84b	ND	266±0.21h
Onion bulb		5.35±0.26f	126±0.13h	139±0.18a	ND	271±0.11g
Green onion		8.78±0.02d	293±0.41d	46.6±0.17f	28.1±1.00	377±0.33d

Values are expressed as mean±SD (n=3). Means with different superscripts within each column are significantly different (p<0.05) by Duncan’s multiple range test.
Tartaric acid and succinic acid were not detected (ND).