Chemical and elemental analysis of the edible fruit of five Carpobrotus species from South Africa: assessment of nutritional value and potential metal toxicity.

Edible wild fruits of five Carpobrotus species (C. acinaciformis, C. deliciosus, C. dimidiatus, C. edulis subspecies edulis and C. mellei) were assessed for their nutritional value by determining the proximate chemical composition. Fruits were high in moisture (77.6% to 90.3%), carbohydrates (58.8% to 70.3%) and energy (1240 to 1370 kJ 100 g-1), with adequate amounts of protein (8.1% to 26.0%) and low in lipids (0.9% to 2.4%). Elemental concentrations were in decreasing order of Ca > Mg > Fe > Mn > Zn ~ Cu > Cr > Se ~ Ni ~ Co. Most fruits were rich in Cr (contributing between 30% and 143% towards its RDA) and C. delicious and C. mellei being rich in Mn, contributing 49 to 156% towards its RDA. Except for C. dimidiatus, toxicity studies revealed all species to contain low levels of toxic metals (As, Cd and Pb) making them suitable for human consumption.