What visual cue during cooking signals that moisture loss and potential toughness are occurring?

Answer

Little white beads of protein (albumin) weeping out

Observing little white beads of protein, specifically identified as albumin, weeping out of a cooking fillet is a critical indicator that the fish is likely being overcooked. Albumin is the protein that sets as the fish cooks. When these beads appear, it means the muscle fibers have contracted too severely due to excessive heat exposure, physically squeezing out the remaining internal moisture. This results in a fillet that is dry, potentially tough, and lacks the desired succulence, moving away from the ideal state where muscle segments yield easily without shattering.

What visual cue during cooking signals that moisture loss and potential toughness are occurring?
foodcookingfishSensorytexture