The color-changing sports drink: An ingestible demonstration

摘要

Red cabbage (Brassica oleracea) contains anthocyanins that dissolve in water, have antioxidant properties, and have a fairly wide range of color changes owing to changing pH. These characteristics not only make red cabbage useful as an acid-base indicator for pH demonstrations in the classroom but can also be made into a visually dynamic, color-changing, hypotonic "sports drink" that is safe to consume at the end of the experiment. When combined with readily available kitchen ingredients, this experiment is inexpensive, visually compelling, and easily scaled up to allow classroom participation.