Nutritional value of grain and leafy Amaranth varieties grown in Tanzania

Abstract

Amaranth leaves and seeds are highly nutritious, but less is clearly known for the varieties grown in Tanzania. Grains, leaves (dry and fresh) and flower part of amaranth were analyzed for minerals (iron, zinc, copper and manganese), proximate (crude protein, crude fat, crude fibre and carbohydrate) and anti-nutrients (nitrate and oxalate) content. Minerals were significantly higher (p<0.05) in fresh leafy varieties performing 75.89 mg/100 g, 3.284 mg/100 g and 34.869 mg/100 g for Amaranthus hypochondriacus (Nafaka), A. hypochondriacus (Lishe njano) and A. dubius (White local) respectively, with iron being significantly higher in dried leaves (284.384 mg/1000 g) of A. dubius (Bwasi jekundu). Protein, Fat and Fibre content is significantly higher in grains of amaranths indicating Crude protein (15.787%) in A. cruentus (Bwasi kijani), Crude Fibre (13.040% and 13.163%) in White local and Bwasi jekundu respectively that are not significantly different (p>0.05) and Crude Fat (9.273%) in Bwasi jekundu. Total Carbohydrate (78.743%) is significantly higher in dried Bwasi kijani. Anti-nutrient contents were significantly higher in dried compared to fresh leaf varieties, grain and amaranth flowers. Oxalate ranging from 378.5 to 360.3 mg/100 g and are not significantly different (p>0.05) within varieties, nitrate (137.06 μg/g) is significantly higher in A. hybridus (Lishe nyeupe) of dried leaves compared to fresh, grains and amaranth flower. Bwasi jekundu appears to be the best variety as dried leaves have the highest iron, since micronutrients are of more significance in leaves of vegetables than macro nutrients.