Comparative Study of Antioxidant Activity and Mineral Composition of Methanol Extract of Seeds of Ripe and Unripe Avocado Pear (Persea americana, Mill.)

Abstract

Avocado pear has been used for many years as a rich source of nutritional and medicinal material in oriental medicine and several health benefits have also been attributed to its seeds. This study was designed to investigate the mineral composition and antioxidant activities of the seeds of ripe and unripe avocado pear. The concentrations of sodium (Na), potassium (K), calcium (Ca), zinc (Zn), iron (Fe), manganese (Mn), and magnesium (Mg) were investigated. The antioxidant activity was investigated using DPPH, superoxide, and hydrogen peroxide scavenging assays. Mineral analysis showed that the seeds of ripe avocado pear contain higher values of Na (96.1mg/kg), Ca (2353.1mg/kg), Mg (392.2mg/kg), Fe (420.65mg/kg) and Mn (890mg/kg) compared to the unripe seeds (Na:84.25mg/kg;Ca:1566.5mg/kg; Mg:365.15mg/kg; Fe:299.7mg/kg; and Mn:10.15mg/kg). The concentrations of potassium (4483mg/kg) and zinc (113.35mg/kg) were, however,
higher in the unripe seeds than in ripe seeds (K: 3982.5mg/kg and Zn: 81.3mg/kg). Antioxidant activity assays showed that seeds from ripe avocado pears exhibited higher free radical scavenging ability with lower IC 50
values relative to the unripe seeds. The findings of this study suggest that the seeds from both ripe and unripe avocado pears contain significant antioxidant potentials which could offer great health benefits. The result
further suggests that seeds from unripe avocado pears, being rich in potassium compared to sodium, could be used in the management of hypertension.