Preliminary Investigation on the Effect of Drying on the Physicochemical Properties and Bioactive Compounds of African Star Apple

Abstract

Preliminary comparative assessment of some quality indices of African star apple as affected by drying methods was carried out. Wholesome African star apple were manually separated into pulp and peel, the pulp and peel were respectively dried using sun, tray dryer and hot air oven. Some physicochemical parameters and bioactive compounds of the six samples of dried pulp and peel of African star apple were evaluated using standard biochemical protocols. The results show that the cold water solubility, hot water solubility, pH, titratable acidity, vitamin A and vitamin C contents of pulp and peel samples were 2.0 - 10.0%, 4.0 - 12.0%, 2.3 - 2.7, 0.28 - 0.47%, 198.00 - 407.84 unit/g and 10.45 - 15.85 mg/100g respectively. Total phenolic content (29.71 - 37.72 mg/g), total flavonoid content (0.29 - 0.39 mg/g), cardiac glycosides (15.59 - 23.44 mg/g), terpenoid (12.23 - 25.19 mg/g) and tannin (3.69 - 5.05 mg/g) were all relatively higher in peel than in pulp. Pulp samples have desirable physicochemical attributes and lesser quantity of bioactive compounds when compared with peel samples.