Development of preservation system of agricultural products by the use of structured water

为了从实验上支持结构水的形成抑制农产品代谢的原理，用核磁共振谱仪测量了化学位移和质子弛豫时间。将给定质量的蒸馏水倒入核磁共振管中，然后将氙气叠加到0.7 MPa。氙溶液的化学位移大于普通水的化学位移。这表明了氢键水分子数量的增加。在氙溶液中也观察到自旋-晶格弛豫时间的减小。为了将该方法应用于西兰花的保存，在288 K的保存温度下，用分压为0.28 MPa的氙气测量了西兰花的呼吸代谢。保存9 d后，对照样品和氙处理样品的累积量分别为14125 mg CO2/kg和10618 mg CO2/kg。氙气处理样品的呼吸活性为对照样品的75%。实验还考察了柿子在0.3 MPa的氪、氮、氙作用下的保存效果，以及在283 K的常压（对照处理）下的保存效果。呼吸代谢抑制仅在氙处理的样品中观察到。以上结果表明，该方法对农产品的保鲜是有效的。

In order to support experimentally the formation of structured water which principle to suppress metabolism of agricultural products, chemical shift and proton relaxation time were measured by NMR spectrometer. A given mass of distillled water was pored into NMR tube, then xenon gas was superimposed up to 0.7 MPa. The chemical shift of xenon solution was observed to be greater than that of normla water. This indicated the increase in the numbr of hydrogen-bonded water molecules. The decease in spin-lattice relaxation time was also obeserved for xenon solution.To apply the method for the preservation of broccoli, the respiratoy metabolis of broccoli was measured by applying xenon whose partial pressure was 0.28 MPa at the preservation temperature of 288 K.After 9 days preservation, cumulative quantities were 14125 mg CO2/kg and 10618 mg CO2/kg for control sample and xenon treated sample, respectively. The respiratory activity of xenon treated sample showed 75 % of that observed for the control sample. Persimmons were also examined to preserve by applying 0.3 MPa of kripton, nitrogen and xenon, and to preserve in atmosperic air conditon (control treatment) at the temperature of 283 K.The suppression respiratoy metabolism was observed only for the sample treated by xenon.From the results mentioned above, proposed method was shown to be valid for the preservation of agricultural products.