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

为了从实验上支持抑制农产品代谢的结构水的形成，用核磁共振波谱仪测定了其化学位移和质子弛豫时间。将一定质量的蒸馏水注入核磁共振管，然后将氙气叠加到0.7 Mpa。观察到氙气溶液的化学位移大于水的化学位移。这表明氢键水分子的数量增加了。为了将该方法应用于青花菜的保鲜，在288K的保藏温度下，用分压为0.28 Mpa的氙气对青花菜的呼吸代谢进行了测定。在保藏9天后，对照样品和氙气处理样品的累积量分别为14125 mg CO_2/kg和10618 mg CO_2/kg。氙气处理样品的呼吸活性是对照样品的75%。用0.3 Mpa的克利普顿、氮气和氙气对柿进行保鲜，并在283K的常压空气条件下(对照处理)进行保鲜。只有经过氙气处理的样品才能观察到呼吸代谢的抑制。以上结果表明，所提出的方法用于农产品保鲜是有效的。

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.