Extent of thermal decomposition of indole glucosinolates during the processing of canola seed

A series of samples representing various stages of canola seed processing were obtained from two commercial processing plants to assess the extent of thermal degradation of indole glucosinolates during the crushing process. The individual glucosinolate content of all samples was determined along with the content of indole glucosinolate thermal degradation products [indoleacetonitriles and thiocyanate ion (SCN)]. Only minor decomposition of indole glucosinolates was evident prior to the desolventization stage of seed processing. Major decomposition of indole glucosinolates occurred in the desolventization of seed processing with little or no effect during meal drying. Indoleacetonitriles (3‐indoleacetonitrile and 4‐hydroxy‐3‐indoleacetonitrile) and SCN together accounted for 45–60% of the degraded indoles in the samples studied.