NUTRITIONAL EVALUATION, PHENOLIC CONSTITUENTS AND FREE-RADICAL SCAVENGING ACTIVITY OF PEELS AND PULP OF AFRICAN BUSH MANGO (Irvingia gabonensis) FRUIT

Abstract

This paper focuses on the evaluation of nutritional and anti-nutritional potentials, antioxidant, and phenolic constituents of edible portions (peel and pulp) of African bush mango (Irvingia gabonensis) fruit. The nutritional status of I. gabonensis fruit peel and pulp were evaluated by determining the proximate indices, vitamin (A and C), mineral compositions and antioxidant analyses. All these were quantified using standard methods. The results of the proximate analysis showed moisture content (79.4 - 81.33 g/100g), mineral ash (0.59 - 0.87 g/100g), crude fibre (9.32 - 10.27 g/100g), crude protein (1.22 - 1.57 g/100g), crude fat (1.69 - 2.23 g/100g) and carbohydrate (5.78 - 5.98 g/100g) per fresh weights respectively. Among all minerals, potassium was found to have highest values with 31.3 ± 0.62 mg/100g and 29.5 ± 0.78 mg/100g for the peel and pulp respectively. The pulp and peel of I. gabonesis showed almost similar pattern of scavenging activities while the pulp showed higher total antioxidant capacity than peel. Tannin and oxalate contents are lower in the pulp than peel, while the phytate and the alkaloid contents are higher in the pulp extract than peel. HPLC analysis confirmed the predominant compounds which include,  ellagic acid (121 mg/100g); protocatechuic acid (65 mg/100g);  gallic acid (46.2 mg/100g); chlorogenic acid (37.9 mg/100g); caffeic acid (9.33 mg/100g); and kaempferol (3.05 mg/100 g) for the peel extract while pulp gave ellagic acid (0.071 mg/100g); protocatechuic acid (1.65 mg/100g);  gallic acid (3.73 mg/100g);  chlorogenic acid (3.56 mg/100g); caffeic acid (0.85 mg/100g); and kaempferol (0.08 mg/100g).. The underutilized tropical fruit of I. gabonensis has considerable antioxidant activity and may possess phytochemicals that could impact human health.