ISSN: 2155-9600
Amanabo Musa and Emmanuel O. Ogbadoyi
Leafy vegetables generally contain some intrinsic phytotoxins that affect human health negatively at high concentrations. The presence of these toxins which is believed to protect the plant from their preys has severely limited the nutritional potential of vegetables. The reason that, this research was conducted to determine the effect of cooking (fresh leaves of the vegetable were cook or boiled for 5 and 10 minutes) and sun drying on antinutrients (soluble and total oxalates), toxic substance (cyanide and nitrate) and some micronutrients which include vitamin C, β-carotene (provitamin A) and mineral elements (Fe, Mg, Cu, Na and K) in Corchorus olitorius. Results obtained showed that cooking and sun drying significantly (p < 0.05) reduced the antinutrients and toxic substances in Corchorus olitorius except that the reduction in cyanide and total oxalate concentrations with sun drying were not significant (p > 0.05). Corchorus olitorius is an excellent source of β-carotene, vitamin C and some mineral elements. However, both treatments reduce vitamin C concentration significantly (p < 0.05). β-carotene concentration increased in the cooked Corchorus olitorius leaves, while its concentration was reduced in sundried leaves. However, cooking exceeding 5 minutes led to significant (p < 0.05) reduction in β-carotene concentration in the vegetables. Mineral elements (Fe, Cu, Mg, Na and K) in the Corchorus olitorius decreased significantly with cooking, whereas sun drying had no significant effect on the mineral concentrations. The results conclude that moderate cooking reduce the phytotoxins to the tolerable levels without compromising the nutritional values of the vegetable.