Some Indigenous Vegetables of the Hamer and Konso Communities, South Ethiopia: Mineral Composition and Effect of Processing on their Anti-nutritional and Carotenoids Constituents
Getachew Addis *
Ethiopian Health and Nutrition Research Institute, Addis Ababa, Ethiopia.
Zemede Asfaw
`Addis Ababa University, Addis Ababa, Ethiopia.
Zerihun Woldu
Addis Ababa University, Addis Ababa, Ethiopia.
Jojo Baidu-Forson
Bioversity International, Nairobi, Kenya.
*Author to whom correspondence should be addressed.
Abstract
Objectives: To evaluate the level of micronutrients, anti-nutritional factors and carotenoids of selected green leafy vegetables (GLVs) of wild and semi-wild origin, which are used by the Hamer and Konso communities (south Ethiopia). It is also aimed to study effect of processing on anti-nutritional factors and carotenoids of the vegetables.
Methods: Edible parts of target plants were collected, lyophilized and analyzed for minerals, anti-nutrients and carotenoids. Effect of processing on level of anti-nutrients and carotenoides were also investigated. The chemical compositions were determined using standard methods.
Results: On dry weight basis, the GLVs (13) constituted total mineral of 12.5%-25.6%; Ca being highest (1100 - 3419 mg %) and exceptionally high for Justicia ladanoides (6177 mg %). Fe, Mg, Mn and Zn ranged from 11.7-23.14, 175-2049, 3.4-9.9 and 1.2-3.3 mg %, respectively. Anti-nutrients include phenolics (158-1564 mg %), tannins (448-2254 mg %) and oxalates (238-14067 mg %). The total carotenoids (Xanthophylls and Provitamin A carotenoids) content was 117-140 mg %. Except lyophilization, drying methods (sun, shade and drier) significantly reduced most carotenoids and anti-nutrients. Blanching (hot water, saline water and steam) for short duration reduced anti-nutrients but not carotenoids. Drying and blanching combination treatments reduced both anti-nutrients and carotenoids.
Conclusions: The indigenous vegetables are good sources of minerals; pro-Vitamin A and other carotenoides. Their use by the community must be encouraged to tackle micronutrient deficiency and age related diseases. Drying (mainly under direct sun) vegetables should be avoided to retain their constituents of nutritional and biomedical importance.