Proximate composition and mineral content of selected Tanzanian vegetables and the effect of traditional processing on the retention of ascorbic acid, riboflavin and thiamine

Proximate composition, mineral content and the effect of traditional processing practices on the retention of ascorbic acid, riboflavin and thiamine were studied using amaranth, cowpea, peanut, pumpkin and sweetpotato leaves. Results of this study indicated that, crude protein, crude fat, carbohydrate and ash contents were in the range of 20.64--46.56 percent, 2.57--4.34 percent, 35.43--63.50 percent and 8.92--15.69 percent respectively. The mineral content per 100 g of fresh vegetables was in the range of 83.64--229.34 mg, 145.97--780.19 mg, 11.5--2l.31 mg, 43.02--110.30 mg, 0.96--5.90 mg and 0.40--2.24 mg for Ca, K, Na, Mg, Fe and Zn respectively. For ascorbic acid, riboflavin and thiamine, concentrations in 100 g of fresh vegetables were in the range of 43.78--89.00 mg, 0.62--1.71 mg and 0.09--0.30 mg respectively. The traditional processing practices of sun/shade drying and storing in ventilated containers resulted in a significant (P