บทคัดย่องานวิจัย

หมวดหมู่ : ฐานข้อมูลงานวิจัย

Water permeability changes of the cell membrane as a function of time.

Sotome I., Oshita S., Kawagoe Y., De Baerdemaeker J.

5th International Postharvest Symposium . Volume of Abstract . Verona, Italy 6-11 June 2004, p.51

2004

บทคัดย่อ

Water permeability changes of the cell membrane as a function of time. Water loss and microscopic water movement inside tissues or cells are major causes of vegetable deterioration and wilting during the postharvest period.Water loss and water movement caused by respiration and evaporation are influenced by the condition of the cell membrane or other biomembranes.Therefore, for the studying of postharvest technology it is essential to understand the changes in the properties of biomembranes of the agricultural products during the storage.

Changes in water permeability coefficient (Lp) of barley cotyledon cell membrane with time course were measured.The barley were cultivated in our laboratory for 12 days.Its cotyledons were cut from the plant and stored within test tubes at 20 °C in dark.The storage periods were 0, 24, 48 and 72 h.After the storage, protoplasts were separated from te cotyledons and the Lp of the cell membranes were measured by Two Laminar Flow (TLE) Method.Th the TLF Method, the Lp was determined from volume change ratios of the protoplast under the osmotic stress.Initially, the sample protoplasts were osmotically in equilibrium with 0.4 M mannitol solution.The osmotic stress was applied by replacing the surrounding solution of the protoplasts with 0.6 M mannitol solution rapidly.

Before the storage, the average value of Lp was 0.072 pm/s/Pa and it decreased to 0.033 pm/s/Pa after 24 h of storage.However, afterward it increased and was 0.044 and 0.053 pm/s/Pa after 48 h and 72h of storage respectively.It was supposed that decline in functional activities or decrease in amount of the water channels in the cell membrane induced the initial decrease of the Lp and deterioration of phospholipids bilayer composing the cell membrane caused the latter increase of the Lp.