Influence of growth stages on the nutritional value of Momordica balsamina leaf powder

Abstract

The nutritive mineral element concentrations of most African leafy vegetables (ALVs) are influenced by the plant’s growth stages. Momordica balsamina is an ALV in the Cucurbitaceae family, rich with nutraceutical and pharmaceutical properties, available in the plant at different growth stages. A greenhouse study was conducted to determine the responses of the nutritional value of M. balsamina leafy vegetable harvested at different growth stages. Six growth stages, namely, vegetative (reference), bud development, flower initiation, fruit set, fruit development and physiological maturity, served as treatments, with 10 replicates and arranged in RCBD. Treatments had highly significant (P ≤ 0.01) effect on the tested nutritional quality, namely, potassium (K), calcium (Ca), magnesium (Mg), zinc (Zn), iron (Fe) and phosphorus (P). Relative to the reference, K was the highest (1206 mg/L) at flower initiation stage, whereas the highest Ca (127.70 mg/L) and Zn (2.21 mg/L) concentrations occurred at the fruit development stage. At the physiological maturity stage, the highest Mg (25.19 mg/L), P (16.54 mg/L) and Fe (5.49 mg/L) concentrations, were recorded. Noticeably, during early growth stages, P, Fe and Zn were negatively reduced, when compared to K, Ca and Mg, which were increasing at every growth stages. In conclusion, the greatest accumulation of the tested mineral elements was mainly observed as from when the leafy vegetable started setting fruit until physiological maturity stage.