Fruit anthocyanins: colorful sensors of molecular milieu

Fruit anthocyanins can be used to perform interesting, colorful chemistry demonstrations in secondary and undergraduate chemistry courses because they illustrate light absorption, acid-base equilibrium and other chemical principles. These molecules are responsible for various pigments including red and blue in some flowers and can be extracted from fruit or fruit juices such as cranberry juice. They can provide students with hands-on research and experimentation experience. Suggested experiments are included.