Changes in respiration of fresh-cut butterhead lettuce under controlled atmospheres using low and superatmospheric oxygen conditions with different carbon dioxide levels
Víctor H. Escalona, Bert E. Verlinden, Sabine Geysen and Bart M. Nicolaï
Postharvest Biology and Technology Volume 39, Issue 1 , January 2006, Pages 48-55
2006
บทคัดย่อ
The effect of different O2 levels from 0 to 100 kPa in combination with 0, 10 and 20 kPa CO2 on the respiration metabolism of greenhouse grown fresh-cut butter lettuce was studied. Controlled atmospheres of 20 or 75 kPa O2 with 0 or 10 kPa CO2 showed a constant respiration rate during the first 2–4 days at different temperatures (1, 5 and 9 °C). Therefore, constant respiration rates during a short period of 2–4 days could be considered as valid for a large part of the commercial life of, for instance, a modified atmosphere package development. The fresh-cut lettuce exposed to low O2 levels (2–10 kPa) combined with moderate to high CO2 levels (10 and 20 kPa) had a higher respiration rate than when 20–100 kPa O2 were used. Moderate CO2 levels (10 kPa) reduced the respiration rates of fresh-cut lettuce 20–40% at 9 °C. This effect was less noticed at lower temperatures. Gas composition with high CO2 levels (20 kPa) probably caused a metabolic disorder increasing the respiration rate of fresh-cut butter lettuce. It was concluded that 80 kPa O2 must be used in modified atmosphere packaging (MAP) to avoid fermentation of fresh-cut butter lettuce in combination with 10–20 kPa CO2 for reducing their respiration rate.