Handbook of Food Science and Technology 3

Figure 2.3.
Structure of fish muscle 
Fat is found in different locations in white and oily fish. In oily fish, fat 
serves as an energy reserve and is found in subcutaneous, visceral and 
connective tissues. In white fish, a small proportion of fat is located in the 
cellular membranes and therefore in the muscle tissue; the remainder is 
found in the viscera. Fat in muscle tissue is in the form of phospholipids. It 
does not serve as an energy reserve but can be used as such by white fish 
during periods of prolonged food shortage.
2.1.1.2.
 Comparison of the biochemical composition of meat and fish 
muscle
Overall biochemical composition 
Despite having different compositions, it is possible to compare 
mammalian skeletal muscle and fish muscle since both are primarily 
composed of water, protein, fat, carbohydrates and minerals (Table 2.1).
The protein, sugar and mineral contents do not vary much according to 
the different physiological stages or diet of the animal (e.g. during the 
migration period or spawning season). However the lipid content fluctuates 
significantly: in the case of oily fish, for example mackerel, the fat content 
Myotome
(segment)
Myocommata
(connective tissue)

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70 Handbook of Food Science and Technology 3 
can vary from 4% in spring to almost 28% in autumn. The fat composition of 
meat also varies depending on the diet and age of the animal, but this 
variation occurs mostly in the adipose tissue and hardly in the skeletal 
muscle tissue.
Fish muscle 
Mammalian skeletal muscle 
Water 
70–80 
65–72 
Protein 
16–22 
20–23 
Fat 
1–10 
4–15 
Carbohydrates 
0.3–1.0 
0.5–1.0 
Minerals 
1.0–1.5 
1.0–1.3