Influence of green extraction techniques on green coffee: Nutraceutical compositions, antioxidant potential and in vitro bio-accessibility of phenolics.

Integrated approach of green technologies like enzymatic hydrolysis, steam, microwave and ultrasound assisted
methods for extraction of nutraceuticals from green coffee beans (GCB) were explored. The steam assisted
extraction (SA) increased the yield of phenolics (158.03 ± 1.06 mg CGAE/g) and flavonoids (271.49 ± 1.33 mg
QE/g) compared to other extractions. The combined effect of enzyme assisted extraction (EA) and SA, surged the
total polyphenols (201 ± 2.15 mg CGAE/g), flavonoids (328.6 ± 1.03 mg QE/g), phenolic profile, alkaloids (by
UPLC) and antioxidant capacity significantly (ABTS+: 46.14 ± 2.30 and FRAP: 52.04 ± 1.56 mg TE/g). The in
vitro bio-accessibility studies indicated chlorogenic acid (CGA) was highly bioavailable in gastric (85 ± 2%) as
well as intestinal phase (74 ± 3 %), followed by trans-cinnamic acid (83 % and 46%), quercetin (76 and 47%)
and p-coumaric acid (77 and 42%). The Principal component analysis depicted substantial correlation of steam
and ultrasound assisted extraction methods, bio-actives and antioxidant capacities. This is the first report on EA
and SA reflecting enriched nutraceuticals from GCB, antioxidants and bio-accessibility of phenolics in gastrointestinal
tract. Thus the bio-functionality of GCB as adjuvant or supplementation in health per se finds avenue in
food and pharmacological industries.