Evaluation of the Mineral composition, Phytochemical and Proximate Constituents of three Culinary Spices in Nigeria: A Comparative Study

A comparative assessment of the quantitative mineral composition, phytochemical and proximate constituents of Xylopia aethiopica (fruits), Piper guineense (seeds) and Rhaphiostylis beninensis (roots) was done using standard protocols. Mineral analysis of the culinary spices revealed significant differences ( p <  0.05) in the Magnesium, Zinc, Iron, Selenium, Copper, Calcium, Manganese, Molybdenum, Potassium and Sodium contents of the spices. The respective concentrations of Iron and Selenium (16.03 ± 0.01, 0.25 ± 0.01 mg/L) in R. beninensis were the highest and lowest of all mineral elements evaluated in the three spices. Similarly, the carbohydrate and moisture contents (81.24 ± 0.25%, 0.71 ± 0.01%) of R. beninensis were the highest and lowest among all proximate parameters evaluated in the three spices. However, the Fibre contents of R . beninensis and P. guineense and the ash contents of P. guineense and X. aethiopica respectively, showed no significant differences ( p >  0.05). Moreover, flavonoid and oxalate concentrations (4.04 ± 0.09%, 0.25 ± 0.04%) in X. aethiopica were the highest and lowest of phytochemicals in the three spices respectively. Nevertheless, there were no significant differences ( p >  0.05) in the tannin content of P. guineense and X. aethiopica spices respectively. Similar trends were observed between the oxalate contents of R. beninensis and X. aethiopica , the phytate contents of R . beninensis and P. guineense and the saponin contents of the three spices respectively. These results indicate that the spices are notable sources of essential nutrients and phytochemicals. Therefore, they are possible candidates in the search for natural ingredients to formulate drugs and nutraceuticals by pharmaceutical industries.