Influence of Different Extraction Methods on the Changes in Bioactive Compound Composition and Antioxidant Properties of Solid-State Fermented Coffee Husk Extracts

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

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