Temperature is the main abiotic factor influencing the metabolic process and growth in fish. It influences the timing and duration of most life history stages.
Un-iced fish may suffer severe contractions that tear the flesh and produce an unsightly product.
The growth of bacteria and the rates of enzymatic and chemical activity are directly related to temperature.
There are at least three reasons why fish spoil so rapidly at refrigerator temperatures. Primarily, because they are readily digestible; second, because the muscle glycogen is nearly depleted during harvesting , leaving little to be converted to acid, which would act as a preservative.; finally , because the bacteria found on fish are psychrophiles – that is, they can grow well at low temperature.
Research shows that refrigerated must be maintained near 0°C for maximum quality retention.
It is well known that both enzymatic and microbiological actvoty are greatly influenced by temperature. However, in the temperature range from 0 to 25° C microbiological activity is relatively more important temperature changes have greater impact on microbiological growth than on enzymatic activity.
Among psychrophiles there is a range of optimum growth temperatures for different species , ant it is known that some of the psychrophilic bacteria found naturally on fish grow at such low temperature that they are reliably detected by standard bacteriological plating techniques.
Fish and temperature
