Fish, radiation pasteurization

HPhe irradiation of fishery products covers a broad area and includes microbiological, biochemical, organoleptic, and engineering problems in the field of fishery technology. Many advances have been made in recent years in the radiation pasteurization of fish and shellfish. 

Table I. Storage-Life Range of Radiation-Pasteurized Fish and Shellfish of the Pacific Coast at Tentative Recommended Levels of...

Radiation Biochemistry of Carbohydrates. Normal autolytic processes are not affected by pasteurizing doses of ionizing radiation. The principal source of volatile base in irradiated and unirradiated or sterile fish or shellfish tissues is through enzymatic amination of adenosine monophosphate to the flavor-active compound inosine monophosphate. 

Lower dose treatments, often referred to as pasteurization doses, have shown much more promise. In particular, doses sufficiently low to cause no significant odor and flavor change in the food are adequate to eliminate the hazards to health associated with salmonella and nematode contamination. For example, the irradiation of frozen meat, whole egg and egg products used in baking, and high protein animal foodstuffs is under active investigation as a means of elimination of salmonellae. At the moment, however, this cannot be classed as an industrial application, since only a few tons have been irradiated in pilot experiments.The shelf-life of white fish kept on ice has been considerably extended by small doses of radiation, and in the United States a full-scale plant for the irradiation of fish has recently been completed. Fish remain an underused protein resource available for the underdeveloped countries, and a big expansion in fish consumption is likely if the world s protein requirements are to be met. Inevitably, the development of fish resources must go hand in hand with satisfactory transportation in view of the relatively limited shelf-life... 

On the whole, in spite of a very large effort in the field, radiation treatment of food cannot be said to have achieved its early promise. Low-dose pasteurization procedures offer the most commercial promise, and they might find their place among other competitive processes. The radiation process may have a particular value, not in countries such as those of Western Europe or the United States, but in the large underdeveloped areas of the world where wastage is high and diet inadequate. There is much evidence of protein deficiency, and a substantial portion of this could be alleviated by better distribution methods, particularly of meat and fish. 

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