Evaluation of Nutritional and Anti-nutritional Compositions of Leaves of Gingko biloba (Maiden Hair) Tree Found in Nigeria.

ABSTRACT

Ginkgo biloba (GB) leaves and extracts have been recognized worldwide for its renowned nutritional and medicinal properties. GB tree is highly grown and used in Asian and South American countries unlike Nigeria. In this study, we examined the nutritional and anti-nutritional compositions of GB leaves (whole dried, and aqueous and ethanol extracts) grown in Nigeria. Association of Official Analytical Chemists (AOAC) method was used to determine the proximate and vitamin compositions while Atomic Absorption Spectrophotometer (AAS) was used to analyze the minerals. Anti-nutrients analysis was done using gas chromatography. The results of analyses on whole dried leaves showed that the nutritional composition was high in carbohydrate (59.70 1.02mg/100g) and energy value (287.00 2.59Kcal/g) and low in protein (6.65 0.38mg/100g), lipid (2.40 0.14mg/100g), fibre (2.50 0.21mg/100g) and moisture (15.65 0.38mg/100g). High concentrations was also observed for vitamins A (79.75 9.05), C (79.20 2.56) and E (59.31 2.84) while vitamins B , B , B , B  and B   (1.53 0.04, 2.98 0.62, 2.44 0.25, 3.57 0.24 and 0.28 0.01 mg/100g) respectively, were found in lower concentrations. The mineral analysis also showed high concentrations in macro minerals especially calcium and magnesium (24.620 0.410 and 18.450 0.28mg/100g) followed by phosphorous (4.896 0.003mg/100g), potassium (4.332 0.000mg/100g), and sodium (2.340 0.001mg/100g). The concentrations in micro minerals were iron (6.667 0.003mg/100g), zinc (1.851 0.001mg/100g), manganese (0.626 0.025mg/100g), copper (0.640 0.000mg/100g) and selenium (0.391 0.003mg/100g). However, the absence of molybedenum (Mo) in the leaves was observed. The calcium/phosphorous and sodium/potassium ratios were 5.029 0.087 and 0.540 0.000 mg/100g respectively. The anti-nutrients analysis of the aqueous and ethanol extracts of the leaf showed low concentrations of phytate, oxalate and tannin. The low concentrations observed are considered to be non-toxic to man. These investigations have revealed the nutritional potentials of  leaves grown in Nigeria. The findings therefore, will be useful for nutritional and medical practice in Nigeria and beyond for maintenance of good health of individuals., Nutritional compositions, Anti-nutritional factors, Gas chromatography, Atomic absorption spectrophotometer