Storage of agricultural products by the control of gas composition and total pressure

通过对菠菜表面附着细菌的生长和菠菜呼吸代谢的研究，考察了环境气体组成和总压对菠菜贮藏的影响。将周围气体组成分为3种类型，即5kPa氧气+20kPa氮气、5kPa氧气80kpa氮气和21kPa氧气80kPa氮气。第三种气体成分作为对照。贮藏温度为283K和288K，贮存期为11~19d。在低氧浓度(5kPa)和常氧浓度(21kpa)下储存的样品，储藏前的细菌数量几乎相同。在贮藏期间，附着在生菜样品上的细菌生长。在储藏结束时，在正常氧气浓度下，细菌数量增加到10的8次方以上，而在低氧气浓度下，细菌数量变得小于或等于10的6次方。细菌的生长并不依赖于周围气体的总压力。上述细菌生长的结果在283K和288K的贮藏温度下都得到了证实。低氧贮藏的生菜样品的二氧化碳累积释放量也被抑制到正常氧气浓度下生菜的70%-80%。

The effect of surrounding gas composition and total pressure on the storage of spinach was examined through the growth of bacteria attaching to spinach and the respiratory metabolism of spinach. The surrounding gas composition was set into 3 types, that is, 5 kPa of oxygen + 20 kPa of nitrogen, 5 kPa of oxygen 80 kPa of nitrogen and 21 kPa of oxygen 80 kPa of nitrogen. The third type of gas composition was used as a control. The storage temperature was 283 K and 288 K and storage period was 11 to 19 days. The number of bacteria before storage was almost same for both samples stored in low oxygen concentration (5 kPa) and normal oxygen concentration (21 kPa). Bacteria attaching to lettuce sample grew during storage period. At the end of storage, the number of bacteria increased to more than or equal to 10 to the 8th power in the case of normal oxygen concentration, however it became less than or equal to 10 to the 6th power in the case of low oxygen concentration. The growth of bacteria did not depend on the total pressure of surrounding gas. The results of bacterial growth mentioned just before were confirmed for both storage temperatures, 283 K and 288 K.Cumulative quantity of carbon dioxide evolved from lettuce sample stored in low oxygen concentration was also suppressed to 70 to 80% of that evolved from lettuce in normal oxygen concentration.