Proximate and bioactive contents of some selected Vegetables in Nigeria: Processing and Varietal effects

Abstract

Leaves of four varieties of vegetable were subjected to two processing methods which are sun drying and blanching. This study aims at assessing the effect of some post harvest treatments on the nutrient, anti-nutrient and anti-oxidant potentials of the leafy vegetables. In this study fresh leaves of Vernonia amygdalina, Basella alba, Telferia accidentalis and Talinium Triangulare were subjected to the processing methods mentioned earlier, the vegetables were blanched at 60 o C. The proximate, bio-active composition (Tannin, Phytate, Vitamin C, and Beta carotene) were subsequently determined. The result of the study shows the various parameters of the vegetable samples. However, the various conventional food processing techniques caused a significant decrease (P<0.05) in the Vitamin C and Total Beta Carotene content while it caused little significant increase (P>0.01) in the tannin and phytate content. The processing methods brought about inconsistence change in the proximate result, some samples increase while some decreased. In conclusion, all these vegetables samples have very high nutrient, anti-nutrient and antioxidant potential; however the various conventional post-harvest treatment caused a significant decrease (P<0.05) in the nutrient and bio-active content, and at the same time caused a significant decrease in the anti-nutrient and antioxidant potential.