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Atmospheric CO2 Enrichment and Therapeutic Compounds of Ginger Root
Ghasemzadeh, A. and Jaafar, H.Z.E. 2011. Effect of CO2 enrichment on synthesis of some primary and secondary metabolites in ginger (Zingiber officinale Roscoe). International Journal of Molecular Sciences 12: 1101-1114.

The authors write that ginger (Zingiber officinale Roscoe) "is an important horticultural crop in tropical Southeast Asia," noting that it is the Asian continent's "most widely used herb" and that it "contains several interesting bioactive constituents and possesses health promoting properties (Rozanida et al., 2005)." However, they lament the fact that "no information is available on the effect of CO2 concentration on the polyphenolic content and scavenging capacity against active oxygen species of Malaysian young ginger varieties."

What was done
In an effort designed to address this lack of pertinent data, the two Malaysian scientists grew two varieties of ginger (Halia Bentong and Halia Bara) from rhizomes placed in polyethylene bags filled with a 1:1 mixture of burnt rice husk and coco peat for a period of 16 weeks in controlled-environment chambers maintained at two different atmospheric CO2 concentrations (400 and 800 ppm), during and after which time they measured a number of important plant properties.

What was learned
In response to the increase in the air's CO2 content, Ghasemzadeh and Jaafar found that the rate of photosynthesis was increased by 65% in Halia Bentong and by 46% in Halia Bara, which led to total biomass increases of 48% in Halia Bentong and 76% in Halia Bara. In addition, they report that total flavonoids in the new rhizomes of Halia Bentong and Halia Bara rose by 82% and 118%, respectively, while total phenolics in the same two varieties rose by 154% and 183%, respectively.

What it means
In the words of the two researchers, "this study has shown that ginger has good free radical scavenging ability and therefore can be used as a radical inhibitor or scavenger, acting possibly as a primary antioxidant." And they add that increasing the CO2 content of the atmosphere "can enhance the antioxidant activity of ginger extract, especially in its rhizomes," which can be of great value in that it thereby "increases the concentrations of several therapeutic compounds."

Rozanida, A.R., Nurul Izza, N., Mohd Helme, M.H. and Zanariah, H. 2005. Xanwhite TM -- A Cosmeceutical Product from Species in the Family Zingiberaceae. Forest Research Institute, Selangor Malaysia, pp. 31-36.

Reviewed 11 May 2011