Have you ever had raspberries turn blue when baking muffins or cakes?

This happened when we tested Raspberry Butter Cake. We turned to food scientist Shirley Corriher for help.

Some red fruits and vegetables contain a compound called anthocyanin that changes color when exposed to changes in acidity or alkalinity, according to Corriher. A red berry will stay red if it's paired with enough acid. But if the conditions become alkaline, the berry and the batter around it will turn blue.

To solve the problem, Corriher suggests using an acidic ingredient, such as lemon juice, buttermilk or sour cream, for some of the liquid. We added 2 tablespoons lemon juice to the cake recipe, and it turned out beautifully. You can also use this tip to retain the color when cooking red cabbage or beets.