Table 7. Antioxidant activities of cookies with different amounts of onion peel powder

Measurement	Group1)				F-value
	Control	OP2	OP4	OP6
Total polyphenol (mg GAE2)/g)	0.63±0.234)b5)	1.13±0.32aB	1.36±0.08aB	2.01±0.47a	9.79**6)
Total flavonoid (mg QE3)/g)	0.11±0.02d	0.43±0.03c	0.57±0.03b	0.68±0.08a	76.17***
DPPH radical scavenging activity (%)	25.62±2.98c	49.22±4.59b	61.85±2.07a	63.80±3.23a	82.59***
ABTS radical scavenging activity (%)	11.82±0.82d	51.11±2.97c	65.14±0.90b	70.08±1.24a	701.31***

Control, no onion peel powder added; OP2, 2% onion peel powder added; OP4, 4% onion peel powder added; OP6, 6% onion peel powder added.
GAE, gallic acid equivalent.
QE, quercetin equivalent.
Values represent the mean±SD (n=3).
Different superscripts in a same row indicate significantly different by Duncan’s multiple range test (p<0.05).
p<0.01, ^***p<0.001.