Ionizing radiation treatments

In the initial bench-scale testing of high-energy ionizing radiation treatment technology, researchers stated that to reduce the level of PCBs to meet federal requirements, a 15-MegaRad... 

At low and medium doses, it is well established that the nutritional value of proteins, carbohydrates, and fats as macronutrients are not significantly impaired by irradiation, and neither the mineral bioavailability is impacted. Like all other energy depositing process, the application of ionizing radiation treatment can reduce the levels of certain sensitive vitamins. Nutrient loss can be minimized by irradiating food in a cold or frozen state and under reduced levels of oxygen. Thiamin and ascorbic acid are the most radiation sensitive, water-soluble vitamins, whereas the most sensitive, fat-soluble vitamin is vitamin E. In chilled pork cuts at the 3 kGy maximum at 0-10°C, one may expect about 35 0% loss of thiamin in frozen, uncooked pork meat irradiated at a 7 kGy maximum at —20°C approx., 35 % loss of it can be expected [122]. 

After aflatoxin contamination, perhaps the next most important factor that has a negative effect on human health and food quality is the presence of food borne bacteria. Several routes for reduction of the risk are currently under extensive investigation. One such means of risk reduction is the utilization of ionizing radiation treatments on meat food products. Ionizing radiation has been demonstrated to be an effective method to reduce or eliminate several species of food borne human pathogens such as Salmonella, Campylobacter, Listeria, Trichinella, and Yersinia Chapter 23). If proper processing conditions are used, it is possible to produce high quality, shelf-stable, commercially sterile muscle foods. 

Effects of Ionizing Radiation Treatments on the Microbiological, Nutritional, and Structural Quality of Meats... 

Josephson et al. (115) conclude from their review of the eflEects of ionizing radiation treatment of foods that nutrient destruction, such as to vitamin C, in irradiated foods is no greater than that occurring when food is preserved by more conventional means. In addition, if irradiation is performed on frozen foods, the losses of vitamin C are reduced. 

Along with the above-considered methods it is worth mentioning swelling of film blanks in a solvent followed by its evaporation in a constant electric field, treatment with ionizing radiation, treatment in magnetic fields, and etc. [87]. 

Belenkov AI, Alakhov VY, Kabanov AV, Vinogradov SV, Panasci LC, Monia BP, Chow TY. Polyethyleneimine grafted with pluronic P85 enhances Ku86 antisense delivery and the ionizing radiation treatment efficacy in vivo. Gene Ther 2004 [Epub ahead of print]. 

The theory of radiation-induced grafting has received extensive treatment. The direct effect of ionizing radiation in material is to produce active radical sites. A material s sensitivity to radiation ionization is reflected in its G value, which represents the number of radicals in a specific type (e.g., peroxy or allyl) produced in the material per 100 eV of energy absorbed. For example, the G value of poly(vinyl chloride) is 10-15, of PE is 6-8, and of polystyrene is 1.5-3. Regarding monomers, the G value of methyl methacrylate is 11.5, of acrylonitrile is 5.6, and of styrene is >0.69. 

Hoffman, A. S. Ionizing Radiation and Gas Plasma (or Glow) Discharge Treatments for Preparation of Novel Polymeric Biomaterials. Vol. 57, pp. 141 157. 

A sterilization process may thus be developed without a full microbiological background to the product, instead being based on the ability to deal with a worst case condition. This is indeed the situation for official sterilization methods which must be capable of general application, and modem pharmacopoeial recommendations are derived firm a careful analysis of experimental data on bacterial spore survival following treatments with heat, ionizing radiation or gas. 

Several decontamination methods exist, but the most versatile treatment among them is processing with ionizing radiation. Decontamination of food by ionizing radiation is a safe, efficient, environmentally clean, and energy-efficient process. Shelf-life... 

Reverse osmosis Solvent extraction Ionizing radiation Adsorption Incineration Freezing Distillation Electrolysis Fungal treatment... 

Ionizing agents, 20 154-155 Ionizing irradiation, in wastewater treatment, 25 911 Ionizing radiation... 

In brief, it is postulated that futile repair and endonuclease activation may both lead to DNA fragmentation after FdUrd treatment, with the dominant process depending on a cell-line-specific factor. Neither of the two observed fragmentation patterns resembles the random damage produced by ionizing radiation. 

Szumiel I, Niah AHW. The effect of combined treatment with a platinum complex and ionizing radiation on Chinese hamster ovary cells in vitro. Br J Cancer 1976 33 450. 

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