IJSRP, Volume 5, Issue 12, December 2015 Edition [ISSN 2250-3153]
The effect of cooking on the proximate composition, energy value, ascorbic acid content and selected antioxidant minerals of four edible leafy vegetables used in preparation of local diets was investigated. In raw samples, moisture content ranged from 71.03±0.21 % in oha leaf (OL) to 83.20±0.23 % in curry leaf (CL). Protein was highest (7.10±0.22 %) in garden egg leaf followed by utazi leaf (5.13±0.12 %) then oha leaf (4.50±0.12 %) and was lowest in curry leaf (3.33±0.21%). Total carbohydrate was low in all the samples and was lowest in garden egg leaf (3.47±0.21%) with the highest value of 16.53±0.25 in oha leaf. Garden egg leaf had the highest ash content of 6.50 ± 0.16 % followed by utazi leaf (4.43±0.22 %) while ash was lowest (1.53±0.16 %) in curry leaf. The low caloric values in raw samples, which ranged from 47.7 kcal in garden egg leaf to 101.8 kcal/100g sample in oha leaf, indicates that these edible leaves are not good sources of crude fat, crude protein and total carbohydrate. Heat processing significantly affected moisture content and generally decreased ash, crude protein, crude fat and the ascorbic acid content of all the edible leafy vegetables investigated at P<0.05. Loss in ascorbic acid to the cooking water ranged from 48.78 % in curry leaf to 51.08 % in oha leaf. Results indicate that vegetables analyzed were good sources of iron (Fe), zinc (Zn), copper (Cu), selenium (Se) and manganese (Mn). The study shows that utazi is a better source of mineral than oha leaf. Mineral level were in the order UT>CL>GL>OL. Cooking decreased the level of the minerals Mn, Fe, Zn, Cu and Se.