When sugar is put on raspberries and strawberries a red juice appears?

When you put sugar on red berries, such as raspberries and strawberries, it causes the release of their juices. The sugar draws water out of the berries through a process called osmosis, causing the berries to become limp and release their juices. The red colour of the juice comes from the anthocyanin pigments found in the berries. These pigments are water-soluble, meaning they dissolve in water, giving the juice its characteristic red colour.