Foods 2019, 8, 35; doi:10.3390/foods8010035
The essential micronutrients in indigenous leafy vegetables (ILVs) could substantially
contribute to the micronutrient supply in rural communities in Tanzania, but concentrations differ
between species. Provitamin A carotenoids, tocopherols, ascorbic acid, minerals, and phytate were
analysed in 13 different species using HPLC-, ICP-OES, and photometric techniques. Eight of the
13 ILVs, including Amaranthus ssp. and Sesamum angustifolium, had high -carotene concentrations
(2.91–4.84 mg/100 g fresh weight), which could provide 50% of vitamin A’s recommended
nutrient intake (RNI). Six ILVs including Cleome hirta and Sonchus luxurians had high iron contents
(34.5–60.4 mg/100 g, >50% RNI); Amaranthus ssp. represented the ILV with high calcium, magnesium
and zinc contents (85%, 207% and 21% of RNI per 100 g); Cleome hirta and Cleome gynandra had high
ascorbic acid contents (>15 mg/100 g, 34–35% of RNI), while Sesamum angustifolium was the only
ILV with a high tocopherol content (7.34 mg -TE/100 g). The highest phytate concentration was
found in Amaranthus ssp., which could negatively affect its role as a very good source of minerals.
Results indicate that the analysed ILVs could make a substantial contribution to the vitamin A and
iron supply in the diets of rural Tanzanian populations.