Background: Fruits have become popular in Nigeria as affordable sources of vitamins and minerals. Data on the nutrient content and antioxidant potential of many of the fruits is not readily available. Objective: This study determined the antioxidant activity and Vitamin C content of the juice of four locally available fruits in Nigeria. Methods: Fresh fruits of Chrisophyllum albidum (African star apple), Dialum guineense (African black velvet), Anarcadium occidentale (cashew) and Psidium gaujava (guava) were sourced from markets in Lagos, Nigeria. Their juice was extracted and analysed for phytochemical components and Vitamin C content using High Performance Liquid Chromatography (HPLC) method. The antioxidant activity was assessed in vitro using DPPH (2,2-diphenyl-1-picrylhydrazyl) method and ferric reducing power assay. Total phenolic content was also determined. Results: The samples contained vitamin C in the range of 123-182 mg/100 g of fruit pulp. Psidium gaujava samples showed the highest free radical scavenging activity while Dialum guineense had the strongest ferric reducing power. Total phenolic compounds were highest in the juice of Anarcadium occidentale (566 mg GAE/100 g) and lowest in Dialum guineense (106 mg GAE/100 g). Tannins, reducing sugar, carbohydrates, steroids, glycosides, proteins and saponins were detected in the samples in varying degrees. Conclusion: The juice of the fruit samples contained high amounts of vitamin C and exhibited good antioxidant activity. They can thus be used for prevention of free radical mediated diseases
Ogah et al. (Mon,) studied this question.