Biochemical Changes in Fish Muscle During Rigor Mortis. D. J. NAZIR AND. N. G. MAGAR. lt of Biochemistry, Imtitzrte of Scieme, BombaJ~ 1, Imfia. PDF | Different stages of rigor mortis, autolysis, microbial decompostion was drying, curing, smoking, chilling and freezing to cortol the fish spoilages are also. Rigor mortis (General). • Rigor Mortis as a phenomenon is the stiffness of the muscles of an animal Rigor Mortis in fish is not different in principles from that in.


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Fish & rigor mortis

The texture is both mushy and grainy and the flesh is almost tasteless. It is not delicious. The best of the three is clearly the whole catfish that had just come out of rigor mortis when purchased.

Rowley has indisputably proved his point. We ask Ken Hom, one of the most respected Chinese chefs in America. References 12 Information related to the author Supplementary material 0.

This gaping is apparent on filleting, whether or not the fish has been frozen and thawed, but is worse in frozen fish, whether frozen in rigor or after rigor.

rigor mortis in fish

Relation of the Rigor Mortis of Fish Body and the Texture of the Muscle

Rigor mortis in fish enough, if the temperature is lowered so much that rigor mortis in fish fish starts to freeze while it goes into rigor, the connective tissue is again weakened, this time by the formation of ice, and gaping occurs.

Gaping caused by freezing fish that are going into rigor is more likely to occur in well-nourished fish, where the contractions are stronger than in spent fish. Rough handling of fish in rigor can also cause gaping, because any attempt to bend a rigid fish will break the muscle or the connective tissue.

Damage of this kind is most likely to happen when the fish are being loaded into freezers at sea, and attempts are made to straighten bent fish while they are stiff.


Pressure from the freezer plates can rigor mortis in fish damage rigid fish lying in distorted positions in the freezer. Rigor, however, is only one of several causes of gaping, since gaping is often seen in fillets taken from whole fish frozen post-rigor, and also in wet fish that have never been frozen.

Here gaping is due to prolonged storage, and the longer the fish has been kept the worse it becomes. Some fish are inherently softer than others, and simply handling the fish during freezing, thawing and filleting can cause considerable gaping.

Softness of the flesh can be influenced by the type of feeding, the fishing ground and the stage in rigor mortis in fish spawning cycle.

All these factors may be superimposed on the gaping caused by rigor, thereby making it worse. Gaping due to rigor, then, is most likely to occur in well-fed fish kept at a high temperature and then frozen after they have started to go into rigor, or in fish that are roughly handled while they are in rigor.

Toughness and drip loss The higher the temperature at which a fish goes into rigor, the greater will be the drip loss on thawing and, when the fish is cooked and eaten, it will be tough and stringy; this effect will probably be aggravated when the fish are well fed and not exhausted.

However, it is not rigor alone that causes toughness and high drip loss in thawed frozen fish; the flesh may be rigor mortis in fish tough or it rigor mortis in fish have been toughened by incorrect freezing, cold storage or thawing.

How quickly should fish be processed? | Nofima

Whole fish frozen pre-rigor tend to have a higher drip loss than similar fish frozen in rigor or post-rigor, but this may be due to what is known as thaw rigor, which is explained later.

These distortions will remain throughout subsequent freezing and thawing. When a whole fish goes into rigor, the muscle tries to contract but is prevented from doing so by being anchored to the rigor mortis in fish skeleton, thus setting up the rigor mortis in fish that lead to gaping but, as soon as the fillet is cut off, the restraint of the skeleton is removed and the fillet shrinks.

The extent of the shrinkage depends on the condition of the fish and on the temperature at which it is kept. In addition, the trimming of fillets from a fish in rigor is challenging since the muscle is very hard and it is difficult to remove pinbones.

Fish & rigor mortis | ChefTalk

It is post-rigor fillets that we most often find in shops. They are processed two to four days after death, when the fish is once again flexible.


These fish do not retain fluid in the muscle as well and therefore can lose more rigor mortis in fish drip loss during storage. The texture of the fillets is softer, so they can easily be torn in both the filleting and skinning machines.