Does cooking or ripening reduce the concentration of solanine in nightshade?

Question

I recall a story from one of my Botany professors where he encountered a woman picking Solanum dulcamara (nightshade) berries. When he asked her what she was doing with them, she responded that her husband had her make a pie from them every year. As her husband was presumably still alive, and since I regard this particular professor as reliable, what would have removed enough solanine from the berries to avoid ill effects? Does the concentration decrease upon ripening, or would cooking destroy the toxin? Would that also be why we fry green tomatoes? (As a disclaimer, no-one should eat plants that are known to be poisonous. Even though some people don't react to poison ivy, it is still a bad idea to rub it all over your body.)

Answer 1

Disclamer: Do not eat nightshade berries! Especially if you don't have identification experience, as there are look alike berries and not all nightshades act the same.

Solanine does degrade with heat, but it has to be at a certain heat (170^oC or more) for a specific amount of time. The time needed depends on the volume being cooked. Solanine can also be leeched out with an acid like vinegar.

Solanum dulcamara is not as toxic as some other nightshade group plants like belladonna once the berries are ripe, but they still contain some solanine. There is some risk in consuming them, even when cooked.

Considering the story, I would guess the berries in the pie were cooked for a good long time before baking and likely with special preparation steps that included soaking in some kind of acidic liquid (vinegar, lemon juice, etc.). That family likely had a cultural/family recipe that was tested over generations to help improve chances of making it safe. Also, if it was only eaten once a year, that also reduced chances of toxin dosage reaching lethal levels.