Response of 'Royal Gala' and 'Granny Smith' apples to high-temperature controlled atmosphere treatments for control of Epiphyas postvittana and Nysius huttoni
Lay-Yee, M., D.C. Whiting and K.J. Rose.
Postharvest Biology and Technology. Vol. 12, Issue 2, 1997. pp. 127-136.
1997
บทคัดย่อ
The response of `Royal Gala' and `Granny Smith' apples (Malus domestica Bork.) to high-temperature controlled atmosphere (CA) treatments for control of Epiphyas postvittana Walker (lightbrown apple moth) and Nysius huttoni White (wheatbug) was investigated. Target CA conditions (1.2% O2, 1% CO2) were attained in 6 h while the temperature was held constant at 20°C. The temperature was then increased over 8 h to achieve a temperature of 40°C at the fruit surface. The treatment time was measured from the start of CA establishment. Mean LT99 values for fifth instar E. postvittana and adult Nysius huttoni inoculated onto apples and exposed to CA at 40°C were 14.2±0.1 h and 16.6±0.1 h, respectively. Using the same treatment establishment protocol, apples were subjected to 40°C in air or CA for 17 and 20 h. Following treatment, fruit were either hydrocooled in ambient water, or not hydrocooled, and then stored at 0°C in air for 8 weeks before being transferred to 20°C for 7 days and assessed for quality. With `Royal Gala' apples, the only treatment that showed significant damage (slight internal browning in some fruit) was the hydrocooled 17 h CA treatment. With `Granny Smith', no significant damage was observed in the 40°C air treatments. Both hydrocooled and non-hydrocooled 17 and 20 h CA treatments showed significantly higher levels of damage in the form of internal browning. `Granny Smith' fruit treated at 40°C in air or CA were more yellow than control fruit. High-temperature CA-treated `Royal Gala' and `Granny Smith' fruit were firmer than non-treated control fruit.