Table 4.
Changes in organic acid of the grape vinegar fermentation by initial alcohol content and fermentation stage

Fermentation stage1)	Initial alcohol content (%)	Organic acid (mg%)
		Oxalic acid	Tartaric acid	Malic acid	Acetic acid	Citric acid
		W	6	15.9±0.82)b3)	132.1±1.6c	173.3±3.5d	ND4)	171.3±9.4NS
7	17.2±2.6b		133.4±2.0c	194.7±3.3c	ND	178.7±8.4
8	33.9±0.1a		146.2±8.3b	223.4±0.1b	ND	180.4±0.4
9	33.0±0.0a		158.6±0.6a	235.1±0.6a	ND	185.5±1.1
IAAF	6	24.3±0.0d	132.2±5.1d	167.2±5.5c	ND	152.1±1.7NS
	7	27.1±0.2c	121.1±0.6c	146.8±1.1b	ND	158.9±1.2
	8	31.8±0.1b	144.1±1.4b	203.2±0.4a	ND	163.2±8.6
	9	34.3±1.3a	159.6±6.0a	212.9±12.7a	ND	154.1±39.2
1st stage AAF	6	40.8±0.8d	149.2±13.8NS	147.2±9.5c	5,539.4±10.0c	114.7±4.0NS
	7	54.0±1.1c	155.6±10.3	129.7±6.5d	5,596.3±7.8b	120.5±10.2
	8	146.6±0.5	55.9±0.2b	166.7±2.2b	7,649.3±26.0a	111.0±15.5
	9	59.4±0.2a	154.5±16.5	182.5±0.4a	4,837.3±25.7d	123.8±8.8
2nd stage AAF	6	51.3±0.7c	228.0±9.4NS	317.4±6.9NS	10,351.4±15.8a	311.7±7.6NS
	7	67.6±1.7a	223.4±7.9	305.2±12.5	10,136.2±19.0b	287.9±28.3
	8	59.4±0.1b	227.0±1.2	308.1±1.5	10,085.6±5.0c	279.9±18.3
	9	-	-	-	-	-

W, grape wine; IAAF, initial acetic acid fermentation broth; 1st AAF, 1st stage acetic acid fermentation broth; 2nd AAF, 2nd stage acetic acid fermentation broth
Values are mean±SD (n=3).
Means with different superscripts (a-d) in the same column are significantly different (p<0.05) by Duncan’s multiple range test.
ND, not detected; NS, not significantly different.