1993 年 77 巻 2 号 p. 95-101
In recent years, the effect of far infrared radiation on water characteristics have drawn a strong attention. It is well known that this effect improves the flavor of food and beverage, and also keeps freshness of food. In the measurements of the water clusters using 17O-nuclear magnetic resonance (17O-NMR), it was observed that the line width of the water oxygen signal narrowed. This result implies that the hydrogen bond may have been broken because of the increase in the molecular degree of freedom, resulting in smaller water cluster and faster molecular movement. At present, however, the changes of water clusters caused by infrared heating have not been clearly understood.
The objective of this research is to clarify the effect of infrared radiation on water clusters by means of 12MHz 17O-NMR. In this experiment, only slight changes of water cluster were recognized under infrared heating. It was found, therefore, that the effect of infrared radiation on water clusters was much smaller than expected, and that the molecular degree of water depended on the potential of hydrogen: pH.