Enzyme-assisted extraction of bioactive compounds from ginger (Zingiber officinale Roscoe)

Ginger (Zingiber officinale R.) is a popular spice used in various foods and beverages. 6-Gingerol is the major bioactive constituent responsible for the antiinflammatory, antitumour and antioxidant activities of ginger. The effect of application of α-amylase, viscozyme, cellulase, protease and pectinase enzymes to ginger on the oleoresin yield and 6-gingerol content has been investigated. Pre-treatment of ginger with α-amylase or viscozyme followed by extraction with acetone afforded higher yield of oleoresin (20%±0.5) and gingerol (12.2%±0.4) compared to control (15%±0.6 oleoresin, 6.4%±0.4 gingerol). Extraction of ginger pre-treated with enzymes followed by extraction with ethanol provided higher yield of gingerol (6.2-6.3%) than the control (5.5%) with comparable yields of the oleoresin (31-32%). Also, ethanol extract of cellulase pre-treated ginger had the maximum polyphenol content (37.5 mg/g). Apart from 6-gingerol, 6-paradol along with 6- and 8-methyl shogaols were the other important bio-active constituents in the oleoresin from cellulase-treated ginger.