Table 2.

Antioxidant activities detected by 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging and ferric ion reducing antioxidant power (FRAP) of coffee husk extracts.

Extraction conditions	DPPH (% inhibition)	FRAP (% inhibition)
Method (I): Water extraction of fermented coffee husk at 100°C	20.31bcd ± 1.63	21.46bcd ± 1.53
Method (II): Water extraction of fermented coffee husk at 60°C	17.17cd ± 0.86	16.56cd ± 2.56
Method (III): Water extraction of fresh coffee husk at 60°C	32.00a ± 5.27	35.73a ± 1.25
Method (IV): Ethanol-reflux extraction of fermented coffee husk at 60°C	25.35ab ± 0.61	25.79ab ± 2.61
Method (V): Maceration of fermented coffee husk in ethanol for 6 days	23.35bc ± 3.76	26.01bc ± 1.45
Ground coffee husk	15.34d ± 3.38	12.95d ± 1.22

It shows the mean ± SD (n ≥ 3). Different superscript letters, p ≤ 0.05; same letter (p > 0.05), obtained from ANOVA with the Tukey post hoc test.