Food industry, radiation processing

In industry, radiation is applied both as an initiator and as a control mechanism on one hand, and as a sustainer of reactions on the other. Among the many industrial uses of radiation, one may mention food preservation, curing of paints, manufacture of wood-plastic combinations, syntheses of ethyl bromide, of ion exchange materials, of various graft copolymers, and of materials for textile finishing. In addition, there are important uses of tracers in various process industries and in mining and metallurgy. 

HPhe general benefits derived from using radiation as an agent for proc-essing materials have overshadowed and obscured detailed effects. This report examines one effect—the production of radioactivity in irradiated foods—that has been a deterrent to the participation of industry in the radiation processing of foods. Such a discussion and review of radioactivity production should help to identify the problem and should guide the establishment of future standards for processing irradiated foods for public consumption. This report reviews and emphasizes only certain aspects of radioactivity production and is not intended to be an exhaustive review of the subject. 

Research on the application of radiation processing of polymers, particularly in the food industry necessitates studies on the effects of radiation on various polymer films. This is because different types of radiation may cause different structural changes, rearrangement and fission or formation of chemical bonds in the polymeric film. As a result, the physical,... 

Density gauges based on the absorption of gamma radiation are used wherever the automatic determination and control of the density of liquids, solids, or slurries is important. The oil industry relies heavily on such instmments. Other applications are in the handling of slurries in mineral processing or even in the food industry. One of the earliest users of radioisotope instmments was the tobacco industry, where density gauges make sure the right amount of tobacco is packed into each cigarette. 

PVDF components are used extensively in the high purity semiconductor market (low extractible values), pulp and paper industry (chemically resistant to halogens and acids), nuclear waste processing (radiation and hot acid applications), and the general chemical processing industry (chemical and temperature applications). Fluoropolymers have also met specifications for food and pharmaceutical processing industries. 

Free radicals are formed when most materials are subjected to ionizing radiation, thus ESR can be used to monitor the process. In the food industry such monitoring is extremely important and ESR can assist in direct radical concentration measurement and also in providing a means of measuring the radiation dose. Radiation effects on rocks can be used to measure ages up to one million years. 

Industrial scale of radiation processing is accomplished also on the sterilization of polymeric medical wear [47], food packaged in polymer bags [48] or electrical insulation of wires and cables [49,50]. The radiation technologies are based on the possibility of attaining improved jiroperties and extension of service life is attained. 

Any incident in which the malfunction of a radiation generator or its ancillary equipment used in fixed or mobile industrial radiography, the irradiation of food or the processing of products by irradiation, causes it to fail to de-energize at the end of the intended exposure period or to fail to return to its safe position at the end of the intended exposure period. 

Interest in the use of ionising radiation in the food industry was aroused in the mid-fifties with the availability of large isotope sources and the development of suitable electrical machines such as the linear accelerator. In particular, attention focused on the radioisotope cobalt 60 as a source of gamma rays. During the past 25 years it would be a reasonable estimate that some 50 million curies have been installed in plants situated in various parts of the world. However, the majority of these are employed for the sterilisation of disposable medical products, pharmaceuticals, cosmetic preparations, and laboratory animal diets. Only a few commercial fecilities have been constructed for the processing of human foods. 

Applications of Radioisotopes—Radioactive nuclides have important uses in diagnostic medicine, in cancer therapy, in studying the mechanisms of chemical and biochemical reactions, and as tracers in various scientific and industrial settings. Additionally, radiation processing is used in processing and preserving food. 

Polysulfones also offer desirable properties for cookware appHcations, eg, microwave transparency and environmental resistance to most common detergents. Resistance to various sterilizing media (eg, steam, disinfectants, and gamma radiation) makes polysulfones the resin family of choice for many medical devices. Uses in the electrical and electronic industry include printed circuit boards, circuit breaker components, connectors, sockets, and business machine parts, to mention a few. The good clarity of PSF makes it attractive for food service and food processing uses. Examples of appHcations in this area include coffee decanters and automated dairy processing components. 

---