An assessment of the potential use of DCA (Dynamic controlled atmosphere) storage for export of ‘Cox’s orange Pippin’ apples from New Zealand
Nagin Lallu, Doug Burmeister, Chris Yearsley, David Billing, Paul Pidakala and Matthew Punter
Abstracts, 10th International Controlled & Modified Atmosphere Research Conference, 4-7 April 2009, Antalya, Turkey. 80 pages.
2009
บทคัดย่อ
Potentially DCA could be used during the shipping phase and/or during storage onshore in New Zealand prior to export. In this study, the response of ‘Cox’s Orange Pippin’ apples to DCA conditions was assessed by undertaking a short-term (simulated shipping) trial, a long-term storage trial, and characterising the induction and recovery response ‘Cox’s Orange Pippin’ to anaerobic atmospheres. In the shipping and long-term storage trials, a comparison was made between the responses of ‘Cox’s Orange Pippin’ apples to air, SmartFresh™, CA and DCA storage.
For the simulated shipping trial, fruit from four orchards were held at 3°C in air with or without SmartFresh treatment, a CA of 2% O2 plus 2% CO2 or under DCA conditions where the O2 varied between 0.8 and 1.2% and the CO2 was maintained between 1 and 2%. Fruit were stored for four weeks to simulate the shipping period and then all fruit were transferred to air storage at 3°C for a further four weeks.
For the long-term storage trial, two additional treatments: CA storage with SmartFresh and DCA with SmartFresh were added and the fruit stored for 20 weeks before evaluation after 7 days of shelf life at 20°C. Flesh firmness, background colour and internal ethylene levels of acetaldehyde (AA) and ethanol (EtOH) were determined during exposure of fruit to 0.1 % or 0.5% O2 and after transfer to air.
In the shipping trial, DCA fruit were as firm as SmartFresh-treated fruit or CA fruit at the end of shipping, but after four weeks in air, the SmartFresh-treated fruit were the firmest, although DCA-stored fruit had the best retention of background colour. In the long-term storage trial, the firmest fruit and fruit with the greenest background colour after storage and shelf life were the DCA-stored fruit irrespective of SmartFresh treatment. However, brown discolouration was present in the flesh of some of the DCA-stored fruit and this was related to AA and EtOH levels. Recovery from the induction of increased levels of AA and EtOH in atmospheres of 0.1 % O2 or 0.5% O2 was possible after several days in air, with no visible damage symptoms.
It is concluded that DCA is suitable for long-term storage of ‘Cox’s Orange Pippin’ apples, especially to supply fruit late into the market window. The use of SmartFresh appears to be the best option for shipping and short-term storage.