Spoilage can be non-microbiological, fish lipids contain high proportion of polyunsaturated fatty acids, which are more reactive chemically than the largely saturated fats that occur in mammalian meat. This makes fish far more susceptible to development of oxidative rancidity.
Oxidative rancidity, one of the major causes of quality deterioration in foods, is caused by the oxidative deterioration of lipids by atmospheric oxygen. It is a chemical reaction catalyzed by heat, ultraviolet light, heavy metals and oxygen.
Oxidative rancidity is an oxidation reaction which starts by an unsaturated fatty acid forming a radical. Radicals are highly reactive and will always want to react with something else again. Radicals can be formed spontaneously, for example under influence of light as well as the presence of certain metals.
It is a primary mechanism which deteriorates the quality such as development of off−flavor, rancidity, degradation in texture, changing of color in meat and its products during storage, which renders them and made meat unfit for human consumption. These reactions take meat towards loss of nutritive value and eventually declining consumer confidence in the product.
Oxidative rancidity
