The Effect of Boiling on the Nutrients and Anti-Nutrients in Two non Conventional Vegetables

Abstract

The effect of boiling on the nutrient and anti-nutrient composition of two vegetables Solanum nigrum and Solanecio biafrae was investigated. The vegetables were boiled and the boiled and raw samples were analysed for proximate composition and some anti nutritional compounds. The protein, ash, fat and fibre in Solanum nigrum was found to be 4.63, 2.99, 0.96 and 1.13%, respectively while Solanecio biafrae were 4.03, 2.86, 0.92 and 1.05% for protein crude ash, fat and fibre, respectively. All the nutrient contents were reduced after boiling with a percentage of between 28 and 9.78% with the exception of ash where the percentage loss was 59.79 and 58.52% in Solanecio biafrae and Solanum nigrum, respectively. All the antinutritional compounds investigated were found in the vegetable. The Phytate, tannin, nitrate and oxalate in Solanum nigrum was 1.65, 0.83, 0.36 and 0.50%, respectively and 1.88, 0.92, 0.33 and 0.46% was recorded for Solanecio biafrae for phytate, tannin, nitrate and oxalate, respectively. These antinutritional compounds were reduced after boiling by between 39.7% in Tannin and 20% in Oxalate. These vegetables were not rich in nutrients like some other conventional vegetables; they were also low in antinutrition al content. Most of the nutrients are stable after processing except the minerals as indicated by the ash result, yet the antinutrient were easily destroyed by boiling.