ศูนย์นวัตกรรมเทคโนโลยีหลังการเก็บเกี่ยว

The effect of modified atmospheres on the rate of quality change in ‘Hass’ avocado

Maarten L. A. T. M. Hertog, , Sue E. Nicholson and Kerry Whitmore1

Postharvest Biology and Technology Volume 29, Issue 1 , July 2003, Pages 41-53

2003

บทคัดย่อ

Gas exchange rates and quality changes of avocados (Persea americana, Mill., cv. ‘Hass’) stored at 7 °C in 32 different modified atmosphere (MA) conditions generated using a flow-through system, were monitored to characterise their functional relationship. An integrated modelling approach was used to link rates of quality loss to the rate of gas exchange. This revealed a close quantitative relationship between the gas exchange of ‘Hass’ avocado fruit o­n o­ne hand and weight loss, colour change and softening o­n the other, indicating a direct metabolical link between these processes. High CO₂ lowered the respiratory quotient of avocado, an effect which, based o­n literature, could be explained by a shift from oxidative phosphorylation into the alternative respiratory pathway. In the model approach, the rates of quality degrading processes were linked to oxidative phosphorylation o­nly, assuming this is where ATP was being produced. At high CO₂ levels at aerobic conditions, unaccounted weight loss data indicated a considerable volatile production which, however, was not qualitatively characterised. Both weight loss and colour change indicated the involvement of anaerobic processes at low O₂ levels. At 2 kPa O2 and 0 kPa CO₂ no CO₂ injury occurred, while the change in hue was minimal, weight loss was minimised, and softening was almost completely inhibited. At such low O₂ levels, no additional benefit was found from raising the levels of CO₂.