Phytochemical Properties, Proximate and Mineral Composition of Curcuma longa Linn. and Zingiber officinale Rosc.: A Comparative Study

Aims: To investigate the phytochemical property, proximate and mineral composition of Curcuma longa and Zingiber officinale dried rhizomes.

Study Design: Activity directed phytochemical screening, proximate analysis and mineral composition investigation of C. longa and Z. officinale rhizomes using in vitro methods.

Place and Duration of Study: Medicinal Plants Section, Bioresources Development Centre, Ogbomoso, Nigeria between October and November, 2016.

Methodology: C. longa and Z. officinale rhizomes were separately washed dried (at room temperature) and pulverized. The powdered rhizomes were then used for phytochemical screening, proximate analysis and mineral composition investigation.

Results: Phytochemistry of the rhizomes of the two plants revealed the presence of eleven diverse classes of secondary metabolites of plants. C.longa rhizomes were rich in steroids, anthraquinones and terpenes metabolites when compared with those of Z. officinale. Values obtained for the proximate analysis of C. longa and Z. officinale were; moisture (76.02% and 75.84%), carbohydrate (16.37% and 16.23%), ash (3.04% and 3.28%), crude fibre (1.95% and 2.03%), proteins (1.83% and 1.91%), and fat (0.80% and 0.83%) respectively. There was also a significant increase (P<0.05) in the percentage moisture content of C. longa rhizome when compared with those of Z. officinale. Mineral composition analysis of the rhizomes of both plants gave the following values; iron (0.57% and 0.54%) > potassium (0.42% and 0.42%) > magnesium (0.05% and 0.04%) > phosphorus (0.03% and 0.03%) > calcium (0.02% and 0.02%) > sodium (0.01% and 0.01%) respectively.

Conclusion: The current study revealed that C. longa rhizomes have high moisture content and is rich in steroids, anthraquinones and terpenes phytochemicals than Z. officinale. Therefore, C. longa could be screened and investigated for novel pharmacologically active compounds to combat degenerative diseases for possible integration into the healthcare.