Table 1.

Radical scavenging activities, total phenolic and flavonoid contents of RCB extract

	DRSA	HRSA	SRSA	TP (mgCE/g)	Flavonoids (mgQE/g)
RCB	28.24 ± 2.05a	13.38 ± 1.47a	32.43 ± 2.40b	125.30 ± 17.56	35.45 ± 3.65
BHT	42.73 ± 0.50b	13.76 ± 2.01a	26.48 ± 1.95a	-	-
Ascorbic acid	75.42 ± 3.33c	18.14 ± 1.73b	24.27 ± 2.17a	-	-

DRSA, DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging activity; HRSA, hydroxyl radial scavenging activity; SRSA, superoxide anion radical scavenging activity; TPC, total phenolic acid. Total phenolic acid is expressed as milligrams of catechin equivalents (CE)/g of extract, and total flavonoid content is expressed as milligrams of quercetin equivalents (QE)/g of extract. Butylated hydroxytoluene (BHT) and ascorbic acid at the concentration of 100 μg/mL were used as positive control. Each value represents mean ± SD (n = 4). ^a-cMeans with different superscript letters in the same column were significantly different by Duncan’s multiple range test (p < 0.05)