Kale type Major findings Reference Cooking Processing Conditions Apparatus Finding Brassica alboglabra Novel Microwave cooking Time: 1-3 min Microwave During boiling, the phytochemical decrease can decrease due to oxidative degradation or altercation. [37 , 38 ] Brassica alboglabra Conventional cooking Boiling and steaming Time: 1-3 min Induction cooker and steaming bowl The finding showed that microwave steaming can be recommended for use in the food service industry and domestic cooking because it maximizes the nutritional values of vegetables and convenience. [37 ] Brassica oleracea var. acephala Conventional and novel Boiling, stir-frying, microwaving, and steaming Boiling, stir-frying, and steaming: 5 min Induction cooker, steaming bowl, and microwave The finding found that steaming can be considered the best cooking method to preserve the bioactive compounds and antioxidant activity. [4 ] Kale (B. oleracea L. var. acephala) (leaves ) Domestic cooking Boiling, blanching, and microwaving Boiling: 10 min Stainless steel vessel, steam basket, and microwave oven The current study showed that the steaming treatment can be best to retain the antioxidant compounds in the fresh and frozen kale. [34 ] Brassica oleracea var. acephala cv. Galega Conventional and novel Boiling and vacuum cooking Boiling: Stainless steel pan and water bath The results found that vacuum cooking could be used as an alternative to conventional methods of cooking kale. [3 ] Kale (Brassica oleracea var. acephala ) Conventional and novel Boiling, microwaving, pressure cooking, and steaming Boiling: 10 min Pan, microwave oven, and pressure cooker The finding suggested that steaming is the best cooking method for increasing the concentration of polyphenols and antioxidants. [35 ] Brassica oleracea var. acephala Domestic cooking Electric stove top Time: 15 min Stainless steel pot The results showed that fresh and cooked kale had similar antioxidative potential. [2 ]
