It turned out that salting has even more to offer when applied sparingly to loose, moist fish eggs. A small dose of salt triggers the action of protein-digesting enzymes in the egg, which boost the levels of taste-stimulating free amino acids. It also triggers another enzyme (transglutaminase) that cross-links proteins in the outer egg membrane and helps toughen it, thus giving the egg more texture. By generating a brine that gets drawn into the space between the outer and yolk membranes, salt plumps the egg, making it rounder and firmer. And by changing the distribution of electrical charges on the proteins within, it causes the proteins to bond to each other and thicken the watery egg fluids to a honey-like luxuriousness.