Table 2. Effect of extraction time on total phenolic content (in dry matter) of palm kernel cake and its antioxidant activity index at a liquid-to-solid ratio of 30:1.

t(extraction)/min	w(total phenolics as GAE)/(mg/g)	Antioxidant activity index
10	(2.78±0.14)a	1.29±0.06
20	(5.19±0.02)b	1.24±0.02
40	(6.08±0.16)c	0.86±0.16

Data are presented as mean value±standard deviation of three independent replicates (p<0.01, 95%). Values with different letter in superscript are significantly different (p<0.05 and p<0.01). GAE=gallic acid equivalent