Irradiation processing of fruits and vegetables

HPhe radiation preservation of fresh fruits and vegetables has received considerable attention as one of the promising applications for food irradiation. As with most other applied aspects of food irradiation, however, the process is not without complications. This paper is concerned only with the effect of gamma radiation upon fresh commodities, drawn principally from work conducted at this laboratory. No effort is made to cover all of the changes occurring but rather only a few which illustrate the problems or limit the practical application of the process. 

The effect of radiation on the biochemical processes of fresh fruits and vegetables is of considerable interest from the standpoint of its influence on shelf life. A number of studies on the effect of radiation on respiration have indicated a general stimulation of both oxygen uptake and carbon dioxide evolution during the irradiation period, subsiding to near-normal rates shortly following the cessation of treatment (21, 23, 24, 38). 

In addition to the traditional canning, freezing, pickling and dehydration processes, several new processing techniques have surfaced in recent years. Irradiation with gamma rays, storage with controlled and modified atmospheric environment, reverse osmosis and ultrafiltration will be discussed in subsequent chapters. The emphasis will be on chemistry of quality improvement of the processed fruit and vegetable products. 

Administration (FDA), for example, requires testing of all new drugs, and 80 percent of that testing employs radioisotopes. But radiation is also widely used to treat products, especially in agriculture, where an irradiation process exposes food to gamma rays from a radioisotope of cobalt 60 to eliminate potentially harmful or disease-causing elements. Even livestock products are covered. Like its counterparts in at least ten other countries, the FDA approves the use of irradiation for pork, poultry, and red meat as well as for fruits, vegetables, and spices in order to kill bacteria, insects, and parasites that can lead to such diseases as salmonella and cholera. 

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