Abstract:
The study examined the nutrients and phytochemicals composition of some lesser - known vegetables in Nigeria (Mucuna pruriens and Phyllantus nuriri) and their effects on iron and beta carotene status of rats. Leaf extract was collected from each vegetable. The leaves were separately plucked, sorted and extraneous materials were removed. Then they were washed with deionized water and were pulverized to get the concentrates. Standard methods were used to determine the proximate, some minerals, and vitamins composition as well as phytochemical constituents of the extracts. Animal study was carried out to ascertain the bioavailabihty of these nutrients. Twenty male adult rats were used for the study. They were divided into four groups according to their body weights. The animals were housed individually in metabolic cages. The rats were fed standard rat chow. The extracts were made to provide 0.11 mg/day iron to the rats. The study lasted for twenty eight days. The rat study showed that feeding rats with rat chow supplemented with Mucuna pruriens and Phyllantus nuriri extract improved the hemoglobin levels. Mucuna pruriens contained 11.47% carbohydrates, 3.20% protein, 1.25% ash and 3.82% crude fibre, while Phyllantus nuriri contained 15.47% carbohydrate, 3.87% protein, 3.02% ash and 3.20% crude fibre. The vegetables had significant quantities of calcium (23.45mg and 34.71mg), iron (7.45mg and 11.27mg), Vitamin C (26.16mg and 20.13mg/100mg), vitamin E (3.06mg and 3.62mg) and 3 - carotene (3.62 and 3.65mg) per l00g sample. Anti - nutrients and toxicant levels of the vegetables were low. Mucuna pruriens had 0.004mg phytate and 0.62mg oxalate while Phyllantus nuriri had 1.28mg phytate and 1.31 mg oxalate. Phytochemicals were present in these vegetables. Mucuna pruriens contained 0.003% alkaloids, 0.54% tannins, 7.01% saponins, 3.16% flavonoids, 12.47% cyanogenic glycosides and 1.06% phenols. Phyllantus nuriri had 1.68% alkaloids, 0.68% tannins, 3.95% saponins, 6.22% flavonoids, 1.17% cyanogenic glycosides and 0.21% phenols. The hemoglobin level for Phyllantus nuriri group was 23.73%, while the Mucuna pruriens group was 16.57%. The serum iron, red blood cell count and beta - carotene levels of rats were significantly improved. The recommendations are that the consumption of these vegetables could be useful in addressing some micronutrients and diet - related non – communicable diseases because of their rich and micronutrient and phytochemical constituents. Nutrition educators should use the information from this study to counsel families on the consumption of these lesser - known vegetables. Students should also be assisted to carryout the same study on humans to see the nutritional effect. Organoleptic evaluation of these vegetables should be carried out to evaluate acceptability.
