Table 3. Total phenol and flavonoid contents of onion juice (OJ), black onion juice (BJ), onion vinegar (OV), and black onion vinegar (BV)

	Contents
	Not fermented		Fermented
	OJ1)	BJ	OV	BV
Total polyphenol (mg GAE/g)	98.79±2.49a,2)	99.09±3.77a	91.39±2.32b	90.31±3.1b
Total flavonoids (mg QE/g)	0.14±0.01NS,3)	0.15±0.01	0.13±0.01	0.15±0.00

OJ, onion juice; BJ, black onion juice; OV, onion vinegar; BV, black onion vinegar.
Values are mean±SD (n=3). ^a-bMeans with the different letters are significantly different (p<0.05) by Duncan’s multiple range test.
NS, non-significance.