Detection of trace amounts of active oxygens generating in the daily foods and protection of these harmful substances in our long life time

本工作旨在建立一种检测日常食品中产生的微量活性氧的精细方法。为此，提出了一种极灵敏的单光电子计数方法，用于捕捉食物中单线态氧分子和其他受激分子所发出的光子。虽然这些活性氧仅以极低的浓度存在于我们所处环境的食物和其他物质中，但通常认为它们在人类的衰老过程和致癌过程中起着重要作用。这些年来的研究得到了以下结果：对现有的单光电子计数系统进行了进一步的改进，用于检测食品中受激分子跃迁产生的极弱光发射。一般食品原料的超弱光辐射水平普遍较低。经过热变性后，这些食品材料发射出更高能级的光子。氨基酸在热变性后也会发出更高水平的光。色氨酸和组氨酸是热变性氨基酸中最显著的发光体。在这些发光现象中，氧是必不可少的。光谱分析显示单线态氧参与了这些光发射。专门针对活性氧的清道夫实验指出，活性氧也是这些光发射的重要组成部分。新开发的特殊发光增强剂表明，这些发光热变性材料中存在单线态氧和超氧化物。新鲜蔬菜和水果的提取物非常有效地抑制了加热肉类和变性氨基酸发出的这些光。

This work aims to develop a fine detecting method of trace amounts of active oxygen species generating in our daily foods. 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 our foods. Though these active oxygens exist only in very low concentration levels in foods and other substances of our circumstances, but are generally thougt to play an important role in the aging process and the carcinogenesis of human being. Following results were obtained for these research years.1. Present single photoelectron counting system was further refined for the detection of very weak light emissions those comes out from the transition of excited molecules in food substances.2. Ultraweak light emissions of usual raw food materials were genarally in very low levels. After heat denaturation these food materials emitted photons in higher levels.3. Amino acids also emitted light in higher levels after heat denaturation. Tryptophan and histidine were the most prominent light emitters among the heat denatured amin acids.4. Oxygen was essential throughout these light emitting phenomena.5. Spectral analyzes revealed the participation of singlet oxygen in these light emissions.6. Scavenger experiment specific for active oxygens pointed out that active oxygens 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 heat-denatured materials.8. Extracts of fresh vegetable and fruit very effectively inhibited these light emissions from heated meats and denatured amino acids.