Brassica vegetables are characterised by their low fat content and high vitamin (C, E, B, A and K) and carotenoid content. They are also renowned for their antioxidant properties, which include catalase, superoxide dismutase (SOD) and peroxidase, as well as sulphur-containing glucosinolates, flavonoids, anthocyanins, terpenes and coumarins (Cartea et al. 2011; Kapusta-Duch et al. 2012; Fahey 2016; Sanlier and Guler 2018). These vegetables are also important for their mineral content. Notably, their low levels of oxalic and phytic acids, which bind calcium (Ca2+), increase the bioavailability of Ca2+ (Cartea et al. 2011; Sanlier and Guler 2018). Some studies have also reported that these vegetables accumulate essential minerals, including phosphorus (P), sulphur (S), chlorine (Cl), calcium (Ca), iron (Fe), manganese (Mn), copper (Cu), strontium (Sr), potassium (K) and zinc (Zn) (Jahangir et al. 2009; Cartea et al. 2011; Sanlier and Guler 2018). They also contain alkaloids, cardiac glycosides, coumarins, phlobatannins, quinines, reducing sugars, resins, saponins, steroids, tannins, terpenoids, xanthoproteins and essential oils (Paul et al. 2019).