The total polyphenol content of purified conserve (both
arabica and robusta) obtained from extraction with isopropanol
plus water (60:40) was found to be 32.19 ± 0.63,
31.71 ± 0.25, respectively, as gallic acid equivalents. Here
again isopropanol with lesser water content viz., 70:30
and 80:20 resulted in lower yields of polyphenols. The antioxidant
activity appears to be directly correlated to the
CGA and polyphenol contents of green coffee extracts;
thus, the isopropanol:water (60:40) extract of coffee conserve
(both Arabica and robusta) showed higher activity
as compared to the other extracts (Fig. 1).