Effect of concentration of debittering agent on the mineral, vitamin and phytochemical contents of Lasianthera africana leafy vegetable

Abstract

White variety of Lasianthera africana leaves were blanched in hot water (control) and in different concentrations (0.25, 0.50, 0,75, 1.00 and 1.25%) of unripe plantain peel ash solution for 3 min at 100°C, cooled, drained, oven dried (50°C) for 36 h. Then, raw leaf and all oven dried samples were analyzed for minerals, vitamins and phytochemicals. The raw leaf contained potassium (78.98±0.78 mg/100 g), calcium (190.25±0.44 mg/100 g), sodium (75.69±0.95 mg/100 g), magnesium (14.68±0.74 mg/100 g), iron (3.96±0.55 mg/100 g), zinc (5.95±0.52 mg/100 g), phosphorus (17.79±0.81 mg/100 g), ascorbic acid (109.64±0.08 mg/100 g), beta-carotene (2.86±0.04 mg/100 g), riboflavin (0.22±0.03 mg/100 g), thiamine (1.01±0.06 mg/100 g), alkaloids (2.67±0.33 g/100 g), flavonoids (0.32±0.03 g/100 g), saponins (3.09±0.04 g/100 g) and tannins (0.28±0.01 g/100 g). Blanching the leaves either in hot water or in different concentrations of unripe plantain peel ash solution led to varying losses of the minerals, vitamins and phytochemicals. Samples blanched in different levels of ash solution retained higher mineral content than hot water blanched samples. Percentage minerals retained increase with increased levels of ash in the blanching solution. Conversely, percentage retention of vitamins and phytochemicals decreased with increase in the levels of ash in the blanching solution. Ash concentration had no significant (p>0.05) effect on the levels of magnesium, zinc, beta-carotene and tannins retained in the blanched samples. For higher retention of vitamins and health benefiting phytochemicals, lower concentration of unripe plantain peel ash solution (0.50% to 0.75%) should be used to debitter L. africana leaf.

Effect of Soaking African Yam Bean Seeds in Unripe Plantain Peel Ash Solutions on the Nutrients, Anti-nutrients and Functional Properties of the Flour

“…The mineral elements in the flours increased with increase in the level of unripe plantain peel ash in the solutions used for soaking the seeds. Similar observation was reported for Lasianthera africana leaf blanched in different concentrations of unripe plantain peel ash solution (19). The low sodium content in the flour suggests that it could be used in the formulation of sodium restricted diets.…”

“…The reductive effective of these antinutrients increased with increase in the level of ash in the soaked solution. Similar decreased in anti-nutrients with increase in the level of unripe plantain peel ash in the solution used for blanching Lasianthera africana leaf has been reported [19]. Adeboye and Babajide [21] also reported that leafy vegetables blanched in hot water contained higher anti-nutrients than those blanched in 1% potash solution.…”

“…Flour prepared from the seeds that were soaked in water had lower levels of K, Ca, Na, Mg, Zn and Fe than the values found in the flours prepared from ash solution soaked seeds. Ani et al [19] similarly reported that Lasianthera africana leaf blanched in different concentrations of unripe plantain peel ash solution retained higher levels of K, Ca, Na, Mg, P, Zn and Fe than hot water blanched samples. Also, Ejoh et al [20] reported that leafy vegetables blanched in 2.5% and 5.0% "kanwa" solution exhibited lower mineral losses than hot water blanched samples.…”