Variations in the thiocyanate content of kale varieties

Thiocyanate is widely distributed in Brassica crops. It has been frequently reported that these crops show goitrogenic activity and lead to reduced fertility in livestock. A simple colorimetric method for the determination of the thiocyanate in freeze‐dried samples of Brassica plants has been used to study variations within the plants and among varieties. Intra‐plant variation was found to be large with the highest concentrations in young leaves, necessitating the use of a carefully controlled sampling technique. Significant inter‐varietal differences were found which indicate that it may be possible to breed new kale varieties with a lower thiocyanate content than that present in current varieties grown as food for livestock.