Australian Stonefruit Grower Magazine Issue 2 August 2016 | Page 15

Commercial post harvest options for managing insect infestation *

Feature

Commercial post harvest options for managing insect infestation *
Cost ( per unit )
Fruit quality ( sub tropical and soft fruits )
Operational reliability and simplicity
Range of insects treatable
Toxic chemical residues
Quarantine approval process
Chemicals ( e . g . Dimethoate , Fenthion , Methyl Bromide )
This is a commonly used treatment option but there are some regulatory , supply , safety and environmental risks associated with the chemicals .
Cost competitive .
Fumigation can damage several fruit types .
Some post treatment handling required .
Some insects are either resistent or become resistent .
A risk of chemical residues .
Regulatory restrictions and consumer resistance increasing .
Irradiation
The product is exposed to high-energy gamma or x-rays which is highly effective in killing or sterilising insects .
Resonably cost competitive .
Generally minimal impact on fruit quality .
A simple process that can be applied to fruit that is already packed .
Effective against a broad range of insects .
No risk of chemical residues from treatment .
Limited but growing acceptance in Australia and internationally .
Refrigeration
Cooling the fruit kills insects of tropical or sub-tropical origin over several days . Commonly used .
Resonably cost competitive if energy use not considered .
Exposure to cold temperatures can damage fruit quality .
Some issues with reliability and quality assurance of the process
Not effective against some insects .
No risk of chemical residues from treatment .
Widely recognised and accepted .
Hot water
�������������������������������������������������������������� pests . A rapid method suitable for pre-packed product although with some issues relating to product quality .
Cost competitive .
Adverse impact on quality and self life .
A simple process but fruit shape and size can be an issue
Effective against a broad range of insects .
No risk of chemical residues from treatment .
Widely recognised and accepted .
Vapour heat
Fruit is exposed to heated air in a staged process . Used for special markets .
Relatively expensive .
Adverse impact on quality and self life .
Fruit requires ����������� post treatment handling .
Effective against a broad range of insects .
No risk of chemical residues from treatment .
Limited acceptance .
Controlled atmosphere
Fruit is placed in sealed containers with low oxygen / high CO2 levels . Conditions in containers need to be monitored and fruit needs to have a long-shelf . Commercial use is rare .
Relatively expensive .
Minimal impact on quality for fruits with long shelf life .
Simple process but lengthy and some issues with assurance .
Effective only on a limited range of insects .
No risk of chemical residues from treatment .
Limited approvals .
* This table is Steritech ’ s opinion only and is intended to provide a high-level overview of the different treatment options available . It should not be considered a complete review of all the treatment options and all the possible measures of performance . ���������������������������������������������������������������������������������������������������������������������������������������������
* This table is Steritech ’ s opinion only and is intended to provide a high-level overview of the different treatment options available . It should not be considered a complete review of all the treatment options and all the possible measures of performance . Industry participants are advised to explore options further in order to find the alternatives that best suit their alternative needs .
In the past , Australian fruit has been rejected for that very reason . Now irradiated fruit has boosted trade in tropical fruits in a major way .
With all those advantages , a number of other issues remain . One is simply the location of the plant in Brisbane ; with no Melbourne-based operation , Victorian fruit needs to be transported several thousand km for treatment before export . However , Steritech has medical treatment plants in Sydney and Melbourne and Mr Reilly said the company is looking to expand access to horticultural treatment facilities for southern growing regions .
Another issue is that although irradiated insects cannot grow and reproduce , they are not immediately killed . Researchers at Macquarie University have been working on ways to test the viability of any live larvae found by quarantine officials . However , until such tests are recognised and accepted , a live larvae is likely to be unacceptable to inspectors .
Finally , it is important to test the effects of irradiation by variety . The colour and aroma of Kensington Pride mangoes can be negatively affected by irradiation , especially if the fruit is still green . In contrast , Honey Gold mangoes are completely unaffected .
Despite these issues , food irradiation is an attractive option for industry as it is non-invasive , effective against a broad spectrum of insects , does not heat or wet the fruit , and is a relatively quick and cost-competitive option – so long as transport costs are not excessive .
For more information and questions contact Steritech on 07 3385 8400 or contact Ben Reilly , Export Business Development Manager for Fresh Produce directly by email at breilly @ steritech . com . au summerfruit . com . au august 2016 | Australian Stonefruit Grower 15