Comparative analysis of phytochemical and proximate composition of <i>Allium sativum</i> L. and <i>Zingiber officinale</i> Rosc.

Abstract

Allium sativum and Zingiber officinale are spices with great potentials as food additives and medicinal values. In this study, the phytochemical and proximate composition of the two spices were evaluated and compared. The results of phytochemical screening revealed the presence of saponins, tannins, terpenoids, flavonoids, glycosides and phenols in both the bulb of Allium sativum and rhizome of Zingiber officinale. The bulb of Allium sativum contained significantly higher amount of saponins, tannins and phenols when compared to the rhizome of Zingiber officinale. Zingiber officinale is rich in glycosides and flavonoids as compared to Allium sativum bulb. Terpenoids was the highest phytochemical detected in both spices while phenol recorded the least amount. The proximate composition of both spices showed moisture, protein, ash, fat fibre, and carbohydrate contents with values that ranged between 60.35 ± 0.23-76.48 ± 0.05%,7.52 ± 0.10-10.15 ± 0.02%, 1.51±0.05-1.54 ± 0.05%,1.02 ± 0.02-4.29 ± 0.06%, 2.13 ± 0.06-2.64 ±0.08%, 7.59 ± 0.23-24.82 ± 0.08% respectively. Protein and carbohydrate were significantly higher in Allium sativum bulb as compared to the rhizome Zingiber officinale. Significant differences were not recorded for all constituents analysed except for moisture. The energy content of Allium sativum bulb was higher than that observed for the Zingiber officinale rhizome. The present investigation therefore indicated that variations exist in both the phytochemical and proximate composition of the two spices, thus their use in food recipe should be encourage.

Keywords: Saponins, Tannins, Flavonoids, Allium sativum and Zingiber officinale