Antioxidant activity, total phenols and phytochemical constituents of four underutilised tropical fruits

The antioxidant activity, total phenols content and phytochemical constituents of edible portions of four underutilised tropical fruits; Irvingia gabonensis (African mango), Artocarpus altilis (breadfruit), Annona muricata (soursop) and Annona squamosa (sweetsop) were determined. Extracts of fruit samples were screened for selected phytochemicals using standard methods whereas the total phenols content and antioxidant activity (by free radical scavenging action) was determined by the Folin-Ciocalteu method and DPPH assay, respectively. The antioxidant activities were high with values ranging from 63% inhibition (breadfruit) to 78% inhibition (African mango pulp). African mango seeds had the highest total phenols content (20.96 mg GAE /100g). Tannins, triterpenoids, saponins, sterols, cardiac glycosides, flavanoids and coumarins were detected in most of the fruit extracts. The study revealed that these underutilised tropical fruits have considerable free radical scavenging (antioxidant) activity and an array of phytochemicals necessary to significantly impact health of consumers.