African pear (Dacryodes edulis) pulp antioxidants and bioactive compounds: Outcome of heat treatment

Abstract

The study was aimed at evaluating the effect of heat treatment (boiling and roasting) on the antioxidant properties and phytochemical profile of African pear pulp. African pear was subjected to boiling and roasting treatment at 100 °C for 5 mins and 150 °C for 10 mins respectively. The raw, boiled, and roasted pears were analysed for antioxidants and phytochemicals were profiled using HPLC. The results of antioxidants showed that total phenols (mg GAE/g) decreased by 34 % in the boiled pears and by 18 % in the roasted pears; total flavonoids (Rutin equivalent) decreased by 50 % in the boiled pear while it was not significantly affected by roasting; DPPH radical scavenging abilities decreased from 84.15 % to 50.82 % and from 84.15 % to 57.04 % in the boiled and roasted pears. Beta-carotene was found to decrease by 17 % and 64 % in the boiled and roasted pears. HPLC quantification of phytochemicals revealed Beta Caryophyllene as the most abundant in the raw and heat-treated pears though heat treatment increased all the phytochemicals quantified. Roasting was found to significantly increase all the bioactive compounds quantified. This suggests that the roasted pear will contribute to better nutrition and health security when consumed compared to the boiled pear.