Comparative study of proximate, phytochemical and mineral compositions of edible plant fruits/seeds from Nigerian rainforest

Abstract

Proximate, phytochemical and mineral compositions of Aframomum melegueta, Dacryodes edulis, Dialium guineense, Gambeya albida and Garcinia kola were studied at Umudike, Nigeria. Fruits of these five
plant species were collected in separately labeled and marked polythene bags at the rainforest at Umudike, Nigeria. The edible parts were separated from the non edible parts. The edible parts were put in labeled
envelopes and dried in an oven set at 65 °C for 24 hours. The proximate, phytochemical and mineral compositions of each sample were analyzed at the laboratory of the Department of Chemistry, University of Agriculture, Umudike. There were differences between species in the percent carbohydrate, ash, protein and fibre contents. All the fruits/seeds contained between 3.94 and 11.18 percent moisture, 26.67 and 89.92 percent carbohydrate and between 0.26 and 5.97 percent fat. Iron had a low concentration ranging from 36.43 to 117.83 mg/kg. Nickel and mercury were in trace amount in Dialium guineense and Aframomum melegueta. Calcium ranged from 0.06 to 2.56 mg/100 mg, magnesium ranged from 0.22 to 0.98 mg/100 mg, potassium ranged from 0.26 to 1.05 mg/100 mg, sodium ranged from 0.18 to 0.85 mg/100 mg and phosphorus ranged from 0.14 to 0.76 mg/100 mg. The order of lead contents is as follows: Garcinia kola > Aramomum melegueta > Dialuim guineense > Dacryodes edulis > Gambeya albida. It was concluded that little quantity of
Aframomum melegueta, Dialium guineense, Gambeya albida and Garcinia kola should be taken when the need arises as these contain reasonable amount of copper, zinc, lead and mercury. These metals could have
adverse effects on the liver and kidney of the consumers when a large quantity is taken.