2013 年 51 巻 1 号 p. 17-21
This study was conducted to ascertain the relation between the degree of reduced pressure in flesh intercellular space and water absorption of sweet cherry fruit, which changes with fruit growth, as well as susceptibility to cracking. Results show that the differential pressure between the intercellular space and atmospheric pressure (DPIA) was around −2.2 to −2.3 Pa during fruit growth by 39 days after bloom (DAB). The DPIA on 54 DAB became 6.0 Pa lower than ambient air pressure. The water-absorbing capability (WAC) of the fruit tended to increase concomitantly with decreasing DPIA. Their correlation coefficient was −0.9622**. When the DPIA was −6.0 Pa, the WAC, as estimated as the ratio of volume of inert fluid absorbed to fruit under atmospheric pressure (V inert) against the intercellular space capacity (V int), was around 73%. The WAC fluctuated between 24.4% on 44 DAB and 73.3% on 54 DAB. The cracking index (CI), which was 5.8 in the fruit at the yellow to pink stage (ca. 35 DAB), increased with fruit growth, becoming 64.4 in the fruit at the maturing stage (ca. 45 DAB). However, it decreased to 30.4 in the overripe fruit (ca. 53 DAB). Therefore, results suggest that the water on the fruit surface was sucked into flesh intercellular space resulting from reduction of the flesh intercellular space pressure caused by respiration.
