Table 6 Total phenolic content, total flavonoid content, and antioxidant activity of naked oat flours according to different particle sizes

Components		Control	Fractions of control
			Fraction A (>250 μm)	Fraction B (160-250 μm)	Fraction C (<160 μm)
			Total phenolic content1) (μg/g)		237.8±7.1b4)	281.3±14.7a	217.5±5.4c	187.5±1.8d
Total flavonoid content2)(μg/g)		90.9±6.9b	123.3±0.8a	54.6±2.2c	43.5±1.7d
DPPH radical assay (%)		57.3±0.4b	63.8±0.9a	54.3±1.0c	49.8±0.9d
ABTS radical cation assay (%)		53.4±0.8b	55.2±0.8a	49.3±0.7c	42.4±0.9d
Reducing power		0.23±0.00b	0.25±0.00a	0.21±0.00c	0.19±0.01d
Regression analysis3)	DPPH radical assay (%)	Y=0.150X1+21.694 (R2=0.99)		Y=0.158X2+43.947 (R2=0.94)
	ABTS radical cation assay (%)	Y=0.134X1+19.024 (R2 =0.87)		Y=0.141X2+39.058 (R2 =0.81)
	Reducing power	Y=0.006X1+0.076 (R2=0.97)		Y=0.007X2+0.168 (R2=0.98)

Total phenolic content expressed as μg gallic acid equivalent per g.
Total flavonoid content expressed as μg catechin equivalent per g.
X₁, X₂, Y, and R represent total phenolic content, total flavonoid content, each antioxidant activity, and correlation coefficient, respectively.
Values are mean±SD (n=3). Means with different superscript small letters in the same row are significantly different by Duncan's multiple test (p<0.05).