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

Table 1

Extraction yields and total phenolic content of the lyophilized samples of coffee husks by each extraction method.

Extraction conditions	Extraction yield (% w/w)	TPCs (mg·GAE/g)
Method (I): Water extraction of fermented coffee husk at 100°C	5.1	0.0005^b ± 0.0003
Method (II): Water extraction of fermented coffee husk at 60°C	2.5	0.0004^c ± 0.0002
Method (III): Water extraction of fresh coffee husk at 60°C	4.2	0.0005^b ± 0.0001
Method (IV): Ethanol-reflux extraction of fermented coffee husk at 60°C	1.1	0.0080^a ± 0.0001
Method (V): Maceration of fermented coffee husk in ethanol for 6 days	0.8	0.0080^a ± 0.0002
Ground fresh coffee husks	—	0.0004^c ± 0.0002

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