Health promoting compounds and in vitro antioxidant activity of raw and decoctions of Gnetum aficanum Welw.

Objective To investigate the effect of Gnetum africanum on its pharmacopotency as well as its nutritional properties. Methods The total chlorophyll, carotenoids, proximates, phytochemicals, minerals, vitamins as well as antioxidant assays were performed using standard techniques. Results The raw leaves of the vegetable ( Gnetum africanum ) possessed significant amounts of proximates, phytochemicals, minerals, vitamins, chlorophyll as well as antioxidant activity, but had low levels of carbohydrates and energy value. The cooking method adopted resulted in insignificant loss of lipids, carbohydrates, vitamins, phytochemicals, chlorophyll, significant loss of energy and carotenoids ( P <0.05), insignificant increase in moisture, crude fibre, crude protein, Ca, Fe, Zn, but significant increase in ash, Mg and P ( P <0.05). Conclusions The conventional method of cooking the raw Gnetum africana in Nigeria results in insignificant loss of its lipids, carbohydrates, vitamins, phytochemicals, chlorophyll, significant loss of its energy and carotenoids ( P <0.05), insignificant increase in its moisture, crude fibre, crude protein, Ca, Fe, Zn, but significant increase in its ash, Mg and P contents as well as its antioxidant capacity which confers high pharmaco potency to the cooked form of this vegetable, justifying its usage in the dietary management of a wide array of diseases in Nigeria. The results obtained are discussed from a biochemical point of view.