Fresh Spanish mackerel meat is white, red is spoiled, can not eat, with the extension of storage time, due to myoglobin is oxidized, the meat color will gradually become reddish brown. The darker the color, the less edible.

When the surface of the meat becomes gray or gray-green, or even white or black spots, the microorganisms have produced a large number of metabolites, so the meat can not be eaten.

Expanded Information

Note on eating fish:

1, the fish is too red and white not to eat. Fish due to different varieties, there are tuna such as red meat fish and scallops such as white meat fish, but if the color of the fish is too bright red or bright white, it is likely to be the dye "credit".

2, the kill live fish to put before eating. The quality of the fish is not the best, because the fish will have a "acid" process, need to be placed for a period of time to be more delicious. Small fish like grass carp and silver carp should be refrigerated immediately and cooked after 2 hours, while large fish need to be refrigerated for more than 2 hours.

People's Daily News - 5 ways to simply determine whether meat is spoiled

People's Daily News - Fish too red and white not to eat! These 4 kinds of fish should never be eaten