Goitrogenic content of some leafy vegetables commonly sold in Idah, Kogi State, Nigeria

Abstract

This study examined the goitrogenic content (cyanogenic glucosides, glucosinolates, and Thiocyanate) of Pumpkin leaf (Telfaira occidentalis), Bitter leaf (Vernonia amygdalina), water leaf (Talinum fruticosum) and spinach (Spinach haleracea). The fresh leaves of these vegetables were randomly collected from the farmers and dried at room temperature. The cyanogenic glucosides, glucosinolates
and Thiocyanate contents were analysed when fresh and after drying using standard AOAC methods. Results revealed that fresh sample of Pumpkin leaves contained 0.22 +2.23x 10-7, 0.22 +2.26x10-5, 0.56 +2.50 x 10-6 mean values of cyanogenic glucosides, glucosinolates and Thiocyanate respectively, while the dried samples contained 0.28 + 1x10-6, 0.09 + 1.6 X 10-5, and 0.83 + 1.6 x 10-6rmean values respectively. Fresh samples of spinach contained 0.19 +2.2x 10-7, 0.16 +2.2x10-5 and 0.49 + 1.4 x 10-4 cyanogenic glucosides, glucosinolates and thiocyanate respectively, while for dried samples, the mean values were 0.27 + 1.4 x 10-5, 0.08 + 1.6 x 10-5 and 0.78 +1.4 x 10-5 respectively. Fresh samples of waterleaf had mean values of 0.16 + 1.6 x 10-6, 0.13+2.2 x 10-5 and 0.54 + 1.3 x 10-5 of cyanogenic glycosides, glucosinolates and thiocyanate respectively, while for dried samples the mean value were 0.22 +1 x 10-6, 0.06 + 1.58 x 10-5 and 0.85 + 2.7 x 10-5. The fresh leaves of bitter leaf revealed the mean values of 0.24 + 2.5 x 10-6,0.11+1.4 x 10-4 and 0.44 + 1.1 x 10-4 for cyanogenic glucosides , glucosinolates and thiocyanate respectively, while the mean values for the dried samples were 0.31 + 2.5 x 10-6, 0.04 + 1.6 x 10-3 and 0.74 + 1.3 x 10-5 respectively. The findings revealed that cyanogenic glucosides, glucosinolates and thiocyanate contents of these vegetables were below the recommended