To capture the highest possible concentration of powerful antioxidants, which cooking methods are recommended for purple potatoes?

Microwaving or boiling.

When the primary health objective is to maximize the intake of the beneficial antioxidants present, particularly the heat-sensitive anthocyanins, the preparation method chosen must be gentle. Studies comparing nutrient loss across various cooking techniques indicate that methods involving moist heat or contained environments result in better retention of these delicate compounds. Specifically, microwaving or boiling the purple potatoes are suggested approaches that cause less overall nutrient degradation compared to more aggressive dry-heat methods like stir-frying or baking, which tend to expose the compounds to higher, sustained temperatures.