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

这项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检测方法。为此，引入了一种极其灵敏的单光电子计数方法来捕捉来自我们食物中的单线态氧分子和其他激发分子物种发出的光子。虽然这些活性氧只存在于我们所处环境中的食物和其他物质中的极低浓度水平，但通常被认为在人类的衰老过程和癌症的发生中起着重要作用。这些研究年度取得了以下成果：1.目前的单光电子计数系统被进一步改进，用于检测食品基质中激发分子跃迁产生的非常微弱的光发射。普通食品原料的超弱光辐射一般处于非常低的水平。这些食品材料经过热变性后，会发出更高水平的光子。氨基酸在热变性后也会发出更高水平的光。在热变性氨基酸中，色氨酸和组氨酸是最突出的发光体。在这些发光现象中，氧气是必不可少的。光谱分析揭示了单线态氧参与了这些发光。针对活性氧素的清除剂实验指出，活性氧素也与这些光发射的一个重要部分有关。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.