Evaluation of the physical and chemical characteristics of Tetrapleura Tetraptera fruit from three different ecological zones in Africa
Abstract
Tetrapleura tetraptera (Shum & Thonn.) is a flowering plant in the pea family native to many sub Saharan African countries including Ghana, Nigeria and Uganda. The fruit of T. tetraptera is applied in food and medicine. The fruits are used in food preparation as a flavor and in ethnomedicine for treatment of various diseases. Although the fruits have a potential global market in the food, cosmetic and pharmaceutical industries, they are still harvested from the wild. This study evaluated the physical characteristics, nutritional composition and bioactive component of T. Tetraptera fruits from three ecological zones. Tetrapleura Tetraptera fruits. were collected from a 500 tree plantation at the National Forestry Resources Research Institute ( NAFORRI) of the National Agricultural Research Organisation (NARO). The fruits were analyzed for physical parameters including length (cm), circumference (cm) and mass (g) . The fruits were also analyzed for chemical and proximate parameters including pH, Total dissolved solids, Moisture, Total Fat, Crude Proteins, Vitamin C, Dietary Fiber, Carbohydrates, and Total Energy in addition to beta carotene , vitamin A, total phenols , phytochemical ingredients and essential oil components. The results showed that the mean length of semi deciduous ecological zone fruits were the highest with value of 22.07±2.21 cm while the Wet Evergreen ecological
zone fruits registered the lowest value of 14.90±1.27cm. The circumference of the fruit had the highest value of 13.66±1.20 cm from Semi Deciduous ecological zone while lowest values of 10.89±0.99 cm was from Moist Evergreen ecological zone. The weight of the fruit was highest in semi deciduous ecological zone with value of 49.61±9.12g while the lowest was from Moist Evergreen ecological zone (22.88±6.82 g). The pH (6.13±0.20 ) and total dissolved solids (67.50±0.57 °B ) were highest in the semi deciduous ecological zone fruits while the moist evergreen ecological zone fruits registered lowest value for pH ( 5.90±0.12) and (TDS (59.05±7.28 °B) . The total fat (0.019±0.02 g/100g) and dietary fiber (19.49±0.91 g/100g) were highest in the moist evergreen ecological zone fruits while crude protein (21.93±13.32 g/100g) and total energy (288.74±1.26 Kcal) were highest in semi deciduous ecological zone. Mineral content of the T. Tetraptera fruits had Potassium (8.57±1.48 mg/100g), Iron (23.74±5.29 mg/100g) and Selenium (23.75±1.77 mg/100g) with highest values in the moist evergreen
ecological zone fruits. However, semi deciduous ecological zone had vitamin C (77.06±3.11 mg/100g ) , Total carotenoids (1.63±0.09 mg/100g ), Betacarotene (0.27±0.01 mg/100g ) and procarotenoids (0.14±0.01 mg/100g ) and Vitamin A (0.41±0.02 mg/100g ) with the highest values. Total phenol was highest in wet evergreen ecological zone fruits with a value of
84.18±1.28 mg/100g. The phytochemical ingredients were positive for saponins, tannins, reducing compounds, alkaloid salts, anthocyanosides, coumarins, flavonoids and steroid glycosides except for anthracenosides. The essential oil components with dichloromethane (DCM) and n-hexane after analysis had one and five compounds identified respectively. However, the n- hexane extract had Linalool (48.08 %) and 3-Cyclohexene-1-methanol (38.08%) as the most dominant compounds. The fruits of T.tetraptera from semi deciduous ecological zone were bigger however, most nutritional composition values including fat, dietary fibre, potassium, iron and selenium were high in moist ever green ecological zones. The fruits is also rich in bioactive compounds like saponins, tannins, reducing compounds, alkaloid salts, anthocyanosides, coumarins, flavonoids and steroid glycosides. The dominant aromatic essential oil compounds was linalool.