What preparation step must be performed vigorously for a minimum duration to neutralize PHA?
Boiling vigorously for a minimum of ten minutes
When preparing dried kidney beans, a non-negotiable step involving heat application is required to detoxify the harmful lectin, phytohemagglutinin (PHA). While proper soaking for at least five hours is necessary preparation, the subsequent thermal process is what deactivates the toxin. The text specifies that the beans must be boiled vigorously, meaning at a rolling boil, for a duration of no less than ten minutes. This high heat application for this specific minimum time frame is necessary to fully denature the toxic compound. Following this initial, vigorous boil, the beans can then be simmered gently until they reach the desired tenderness. Failure to meet this minimum boiling threshold risks acute poisoning, even if the beans appear soft.
