4
votes
1answer
167 views

What causes changing blue and purple pigments in food?

I've noticed that many foods, such as cabbage, garlic, and ginger, either turn blue or purple in certain conditions, or that, like purple string beans, they lose these colors when cooked. Why is this? ...
3
votes
2answers
352 views

Why do purple snap beans turn green when cooked?

We often get snap beans from the CSA (Community Sponsored Agriculture) that are either entirely purple or mottled purple. When cooked (at least when steamed or blanched), however, the purple color ...