Why do berries and yogurt separate?

Question

I made two smooties yesterday and put them in the fridge. Today the one I made with yogurt, strawberries, bananas and orange juice was still a liquid, while the one I made with strawberries, blueberries and yogurt was a gelatanous cylinder with the juice separated out. Does anyone know why this would happen? I made them at the same time, and they were about the same consistency when they were both finished. The berries smothie hasn't gone bad, it's just a different consistency. What are the chemical processes at work here? Is is the blueberries or the lack of another ingredient, or what? Just really curious to know.

Answer 1

The berries were more acidic and caused the milk protein in the yogurt to further denature(curdle) and it squeezed the whey out.

Yogurt is already a curded milk product, but a soft curd. Heat will also cause this. Did you use the exact same container of yogurt? There could be a date difference that caused one to be more ready to separate than the other.