Newly Developed Assaying Method for the Harmful Free Radicals and Active Oxygens Generating in Food Substance

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This project pursues a way to develop a new detecting method of trace amiuntof active oxygen species and free radicals generating in food substances. For this purpose an extremely sensitive single photoelectron counting method was introduced to catch such photons coming out from singlet oxygen molecules and other excited molecular species. In general, though these active oxygens and free radicals exist only in very low concentration levels in food and other substances of our circumstances but are thought to play an important role in the aging process and the carcinogenesis of human being. Following results were obtained for these two research years.1. Single photoelectron counting system was introduced to overcome a technical difficulty in the detection of very weak light emission that comes from the transition of excited molecules in food substances.2. Ultraーweak light emissions of usual raw food materials were in very low levels. After heat denaturation meats, fishes and cheese changed to emit photons in very high levels. On the contrary the light emission from boiled rice and bread and bread stayed in low levels.3. Some amino acids also emitted light in higher levels after heat treatment. Tryptophan was the most prominent light emitter among the heat denatured amino acids.4. Oxygen was essential for these light emitting phenomena.5. Spectral analyses revealed the participation of singlet oxygen in these light emissions.6. Scavenger experiment specific for the existence of free radicals pointed out that free radicals are also concerned in an essential part of these light emissions.7. Newly developed specific enhancers of light emission showed that singlet oxygen and superoxide exist in these light emitting denatured materials.8. Extracts of fresh vegetable and fruit effectively inhibited these light emission from heated meats and denatured amino acids. Analysis of the component that inhibits light emission in these extracts is presently under way.