When you're buying fish, you probably look at its color, smell it, and perhaps feel it for texture. If Martine Morzel has her way, you might also perform a mass spectrometry profile.
Morzel, of the French National Institute for Agronomic Research, was interested in what effects preslaughter activity have on the quality of resulting fillets. In typical farming practice, trout kept in a large pond or raceway are sorted, collected in a small area, and then killed, either by individually stunning and bleeding them, or in a group, by electrical shock or removal from water. As they become crowded during collection, the fish become agitated and try to escape. Several previous studies have documented the effects of this preslaughter muscle activity and stress on food quality in farm-raised or experimental tank-raised trout, salmon, and eels. Those studies concentrated on pH, metabolites, or select proteins, but Morzel wanted to cast a ...