Extraction, Characterization and Bioactivity of Coffee Anthocyanins.

Characterization of anthocyanins, polyphenols and the biological properties of coffee skin/pulp,
which is a residue obtained during the coffee processing were investigated. The anthocyanins were extracted
with 0.01 M HCl, purified by Sephadex LH-20 column chromatography and were analyzed by high-performance
liquid chromatography coupled with photodiode array detection, electrospray ionization - mass spectrometry.
The anthocyanins from coffee pulp yielded 25 mg of monomeric anthocyanins / 100 g of fresh pulp on a dry
weight basis. The purified anthocyanin was identified as cyanindin-3-rutinoside and cyanidin-3- glucoside with
mass profile of m/z=594.66. The red color of coffee peels is due to the presence of cyanidin 3-rutinoside
confirmed by 1H-NMR and 13C-NMR. The coffee pulp had 22 mg GAE gG1 of polyphenols and free radical
scavenging-linked antioxidant activity was observed. Coffee anthocyanins have shown multiple biological
effects. The coffee anthocyanins resulted in effective "-glucosidase inhibitory activity with an IC value of 50
0.22 mg/mL and "-amylase inhibitory activity with IC values of 0.43 mg/mL. The coffee pulp, a source of 50
anthocyanins can find an opportunity as colorants and bioactive ingredients for formulated foods. This is the
first report on coffee anthocyanins with their biological activity.