Which cooking method retained the highest levels of cancer-fighting glucosinolates in greens?

Steaming

When evaluating the retention of sensitive compounds like cancer-fighting glucosinolates in cruciferous greens, the mechanism of heat transfer and contact with liquid are crucial factors. Boiling, which involves full submersion, was shown to eliminate a significant portion, roughly three-quarters, of these beneficial compounds through leaching into the discarded water. Pressure cooking, while faster than long boiling, still resulted in a loss of less than half the glucosinolates when immersion occurred. Steaming, however, presents the best scenario because it utilizes the high heat within the pressurized environment without submerging the vegetables, thereby preventing the direct leaching that plagues the other immersion methods. This indicates that avoiding contact with the cooking liquid is paramount for maximizing the retention of these specific phytonutrients.