Author and science educator Adrian Dingle couldn’t get away from chemistry, even on his lunch break. By the time he’d brought his meal—which included red cabbage salad—back to his table, the cabbage juice had soaked into his fish and turned it greenish-blue. The color in red cabbage juice is from molecules called anthocyanins, which change their structure when exposed to acids or bases and, as a result, change their color. Typically, cabbage juice is purplish and has a neutral pH (~7). Because the fish turned greenish-blue when exposed to the juice, the fish must have been slightly basic (pH ~8), Dingle says. Cabbage juice can measure pH values from 2 to 14, changing color from red to blue to greenish-yellow.
Submitted by Adrian Dingle
Do science. Take pictures. Win money. Enter our photo contest here.
Related C&EN Content: