The aim of this study is to investigate the effects of different home cooking techniques (boiling, steaming,
and stir-frying) in kale and red cabbage, on the levels of bioactive compounds (carotenoids, anthocyanins
and phenolic compounds) determined by high-performance liquid chromatography coupled with photo
diode array and mass spectrometry detectors (HPLC–DAD–MSn), and on the antioxidant activity evaluated by ABTS radical scavenging activity , Oxygen radical absorbance capacity assay and cellular antioxidant activity assays. The steaming technique resulted in
a significant increase in phenolic content in kale (86.1%;p< 0.001) whereas in red cabbage it was significantly reduced (34.6%; p< 0.001). In the kale, steaming resulted in significant increases in antioxidant
activity levels in all of the evaluation methods. In the red cabbage, boiling resulted in a significant
increase in antioxidant activity using the ABTS radical scavenging activity assay but resulted in a significant decrease using the
Oxygen radical absorbance capacity assay. According to the cellular antioxidant activity assay, the stir-fried sample displayed the highest levels of antioxidant
activity.