Binary Solvent Extraction System and Extraction Time Effects on Phenolic Antioxidants from Kenaf Seeds (Hibiscus cannabinus L.) Extracted by a Pulsed Ultrasonic-Assisted Extraction

Table 1

2,2-Diphenyl-1-picrylhydrazyl (DPPH) radical scavenging capacity, 2,2^'-azino-bis(3 ethylbenzothiazoline-6-sulphonic acid) (ABTS) radical scavenging assay, total phenolic content (TPC), total flavonoid content (TFC), ferric reducing antioxidant power (FRAP), and 𝛽-carotene bleaching (BCB) assays of kenaf seed extract extracted by different ethanol concentrations and extraction times.

Extraction parameter		DPPH; (%)	ABTS; (%)	TPC; (mg GAE/100 g)	TFC; (mg CE/100 g)	FRAP; (mg TEAC/100 g)	BCB; (%)
Ethanol concentration	Time; (min)
60%	5	28.71±0.55^i	12.86±0.34^e	1579.94±56.23^cd	592.40±4.89^h	1011.91±34.46^i	28.93±0.68^c
	10	35.04±0.62^g	23.54±0.33^d	1757.65±27.80^b	666.67±4.46^g	1137.43±37.35^h	31.07±2.94^abc
	15	42.82±0.33^e	47.02±0.99^c	1913.08±2.14^a	849.74±4.46^f	1299.97±21.27^g	33.56±0.70^a
80%	5	52.89±0.70^c	45.33±1.49^c	1407.21±13.25^f	1670.98±10.69^e	3554.55±86.52^c	28.87±0.58^c
	10	60.35±0.35^b	55.44±1.45^b	1506.92±7.38^e	2394.65±4.35^d	4421.95±39.46^b	34.22±0.54^a
	15	66.68±0.38^a	69.78±0.66^a	1538.59±13.25^d	2705.53±4.90^c	5661.09±29.91^a	33.46±1.10^ab
100%	5	32.07±0.87^h	8.72±0.32^g	1233.31±9.51^h	4082.04±3.31^a	3247.18±21.27^d	31.96±0.40^b
	10	39.68±0.76^f	11.46±0.39^f	1594.31±8.32^c	2836.79±5.90^b	1570.33±16.09^e	18.35±0.76^d
	15	46.94±0.57^d	12.62±0.20^e	1278.77±16.63^g	2393.78±4.46^d	1402.96±28.49^f	15.86±0.51^e

Value are presented in means ± standard deviation (𝑛=4); mean values at the same column with different superscripts are significantly different (𝑃<0.05).
GAE: gallic acid equivalents.
CE: catechin equivalents.
TEAC: Trolox equivalent.