Table 4. Antioxidant activities of ginger powder according to the number of steam-drying treatments

Antioxidant activities	Number of steam-drying treatments				F-value
	0	3	6	9
Total polyphenol contents (mg GAE/g)	56.19±3.131)a2)	66.88±6.17b	79.75±3.53c	80.48±2.12c	24.807***3)
Total flavonoid contents (mg QE/g)	126.33±11.68a	213.41±11.82b	231.99±1.91b	271.71±56.07c	100.598***
DPPH radical scavenging activities (Inhibition, %)	73.25±0.33a	76.21±0.41b	76.88±0.46b	84.50±0.77c	255.155***
ABTS radical scavenging activities (Inhibition, %)	93.66±0.82a	94.84±0.43b	95.27±0.64c	95.72±0.30d	694.289***
FRAP (mM FeSO4/g)	2,824.22±79.93a	3,320.00±107.33b	3,543.56±121.96c	3,840.00±89.27d	54.067***

All values are mean±SD (n=10).
Different superscripts (^a-d) in the same row indicate significant differences by Duncan’s multiple range test (p<0.05).
^***p<0.001.