Oil rapeseeds used to have a high content of erucic acid and glucosinolates that are of concern for animal and human health, but those problems have been eliminated or largely reduced through traditional genetic selection since the 1970s (Snowdon, 2006).
Erucic acid
Erucic acid is no longer present in significant amounts in rapeseeds and canola seeds cultivar grown for food oil production. The concern about erucic acid, which was extremely serious in the 1970-1980s, has somehow diminished today, as its adverse effects on livestock other than poultry remain difficult to prove or at least to separate from those caused by other dietary components (EFSA, 2016). However, the rise of erucic-rich cultivars grown for niche industrial markets (Tonin, 2018) could result in hulls rich in this fatty acid.
Glucosinolates
Rapeseed hulls contain much less glucosinolates than the kernels: in a study based on glucosinolate-rich cultivars, hulls contained in average 10 µmol/g of glucosinolates whereas the kernels contained 10 times more. In modern cultivars containing low amounts of glucosinolates, the glucosinolate content of the hulls should be minimal (Carré et al., 2016).