Why does the shrimp turn red in the pan? - KREUTZERS FOODfacts

The other day, as we sat together enjoying a panful of magnificent Cara Royal White Tiger prawns, along with a bottle of Lagolino (both available at Kreutzers.eu!), the question arose as to why prawns and other crustaceans, initially an inconspicuous gray-blue, turn a vibrant red in the pan. The answer, as you might have guessed, has to do with chemistry.

From blue to red – the cause lies in the molecules!

As we suspected, we were not the only ones asking this question: Dutch researchers from Leiden University investigated the matter with scientific rigor and were able to prove, using magnetic resonance spectroscopy, that the interaction of two color molecules is the reason for the well-known color change!

Crustacyanin and astaxanthin – the reason for red shrimp on the plate!

The two proteins crustacyanin and asthaxanthin are so closely bound to each other in living animals that they form a bond. Normally, asthaxanthin, a red carotene molecule, causes the organism in which it is present to appear red. However, in combination with crustacyanin, the carotene changes its light absorption and absorbs red light instead of blue: the shrimp appears gray-blue (a brief aside: an object that appears red absorbs all colors of light except red. The red light is reflected and enters our eyes. The result: we see the object as red). If the shrimp is now heated, the structure of the crustacyanin changes. The carotene can no longer bind and remains free. When this happens, the shrimp looks orange-red.