1. Exporting Australian avocados:
Challenges, options and research
Peter Hofman and Roberto Marques
Queensland Primary Industries and Fisheries

2. Queensland Primary Industries and Fisheries
How to get there – the cost/quality balance!
• Air
– Generally expensive
– Maintains quality
• Sea
– Cheaper
– May compromise quality because of longer times (10-40 days)
• Combinations of air and sea 60000
Actual Projected
3.5
– Intermediate cost and quality risks
Required consumption (kg per capita)
50000
3.0
– Greater logistical challenges 40000
Required
Volume (T)
2.5
consumption
30000 Production
2.0
20000
1.5
10000
Imports
Exports
0 1.0
8
0
2
4
6
8
0
2
/9
/0
/0
/0
/0
/0
/1
/1
97
99
01
03
05
07
09
11
19
19
20
20
20
20
20
21
Year
© The State of Queensland, Department of Employment, Economic Development and Innovation, 2009

3. Queensland Primary Industries and Fisheries
Seafreight - the tyranny of time
Cold storage at 4ºC
Dixon et al. (2003)
© The State of Queensland, Department of Employment, Economic Development and Innovation, 2009

4. Queensland Primary Industries and Fisheries
The need for best practice from field to fork
• Based on Hazard Analysis
– Draft stage
– Will be refined at end of
season
– Will be the basis for
information guides/training
material
© The State of Queensland, Department of Employment, Economic Development and Innovation, 2009

5. Queensland Primary Industries and Fisheries
Predicting outturn quality-which fruit to export
• Disease load in the orchard
– Everett (2003) using leaf discs
• Fruit “robustness”
– Nitrogen
– Calcium
– Iron
– Maturity
– C7 sugars?
© The State of Queensland, Department of Employment, Economic Development and Innovation, 2009

6. Queensland Primary Industries and Fisheries
Predicting outturn quality – the Avotest
• Harvest sample fruit weeks before shipping
• Combines inoculum load and fruit robustness
100
r ²=0.62
% of ripe fruit with rots harvested at 24%DM
80
60
40
20
0
0 20 40 60 80 100
% of ripe fruit with rots harvested at 19%DM
Le Lagadec et al. (2008)
© The State of Queensland, Department of Employment, Economic Development and Innovation, 2009

7. Queensland Primary Industries and Fisheries
Predicting using non-destructive means
• E.g. near infrared spectroscopy
(NIRS)
• It can sort for dry matter/
moisture content in the lab
• Can NIRS sort for:
– rots?
– more even ripening? (Blakey 2009)
– Poster by Burdon et al.
Wedding et al (2008)
© The State of Queensland, Department of Employment, Economic Development and Innovation, 2009

8. Queensland Primary Industries and Fisheries
In the container……………the key variables
1. Temperature
2. Atmospheres
– Humidity
– Low oxygen and high carbon dioxide
• Reduces respiration rate
• Two main “control” systems
• Controlled atmospheres – full active control
• Modified atmospheres
• Relies on fruit respiration and a “membrane” to restrict gas
movement
• MA packaging - plastic bags etc
• Maxtend
• The reefer container is the “membrane”
© The State of Queensland, Department of Employment, Economic Development and Innovation, 2009

9. Queensland Primary Industries and Fisheries
1. Temperature
• Can we store below 4-5ºC?
– Risk –discrete patches
– Benefits – less flesh defects
– Conditioning before storage
• 3-4 days at 4-6ºC
• Eliminates discrete patches for 20-25 days at 1ºC
• Good cold disinfestation treatment - in transit??
• Also improves internal quality
• Not sure about longer than 25 days
• Not tested in combination with CA
© The State of Queensland, Department of Employment, Economic Development and Innovation, 2009

10. Queensland Primary Industries and Fisheries
Not conditioned Conditioned
At removal from 1 ºC for 16 d At removal from 1 ºC for 16 d
At ripe At ripe
© The State of Queensland, Department of Employment, Economic Development and Innovation, 2009

11. Queensland Primary Industries and Fisheries
2. Atmospheres
• Humidity
– Reduces fruit weight loss
– Controlling water loss from harvest reduces risk of fruit “ripening”
in store
• Can reduce flesh defects
– New containers have larger evaporator coils
• Allows >90% RH
• Oxygen and carbon dioxide
– Literature reports ranges of 2-4% O2 and 4-6% CO2
– Recent static trial gave excellent results after 42 days
© The State of Queensland, Department of Employment, Economic Development and Innovation, 2009

12. Queensland Primary Industries and Fisheries
Controlled atmospheres
Without CA With CA
Grower 1
Grower 2
© The State of Queensland, Department of Employment, Economic Development and Innovation, 2009

13. Queensland Primary Industries and Fisheries
Ways to “control” the atmospheres
Full control
– Nitrogen generator to flush out excess O2
– Introduce air if O2 gets too low
– Flush with air/nitrogen to reduce CO2 buildup
• Recent improvements
– CA system integrated into container
• Increased cargo space
– Smarter atmosphere control – AFAM+
• Better use of air and generator gases
– More powerful CA units
• establish CA more quickly
© The State of Queensland, Department of Employment, Economic Development and Innovation, 2009

14. Queensland Primary Industries and Fisheries
Ways to “control” the atmospheres
Dynamic CA
– Determine best O2
concentrations by measuring fruit
behaviour during storage
– Adjust O2 concentrations to just
above damaging levels
– Currently only used for land
storage in apples etc
– Promising results with avocados
(Burdon et al 2007&8)
© The State of Queensland, Department of Employment, Economic Development and Innovation, 2009

15. Queensland Primary Industries and Fisheries
Ways to “control” the atmospheres
• “Hybrid system - Maxtend
– Uses fruit respiration to reduce O2 concentrations
– Introduces air when O2 concentration gets too low
– Absorbs excess CO2 using satchets
– Similar performance to full CA, but can be cheaper
Include CO2 absorber Seal the container Flush with nitrogen Install the Maxtend controller
© The State of Queensland, Department of Employment, Economic Development and Innovation, 2009

16. Queensland Primary Industries and Fisheries
SmartFreshSM
• 1-MCP
• Similar molecule to ethylene – but different Ethylene
enough
– blocks ethylene from starting the ripening
process
• Applied as a gas soon after harvest 1-MCP
– Cool fruit
– Treat with about 0.5 ppm for about 20 hours
– Handle/store/seafreight as usual
© The State of Queensland, Department of Employment, Economic Development and Innovation, 2009

17. Queensland Primary Industries and Fisheries
Smartfresh - potential
• Internal quality often as good as with CA
• But: No SmartFresh
– variable ripening
– Can get more disease with longer ripening
• Use only during mid-late maturity? (SA)
• Maybe sort with NIRS for even ripening
No SmartFresh
© The State of Queensland, Department of Employment, Economic Development and Innovation, 2009

18. Queensland Primary Industries and Fisheries
Other potential advances
• RFID
– Tracking container movements
• In transit fruit behaviour monitoring
• Infrastructure improvements
– Maintaining the cold chain
• Logistics scheduling
– Reducing time from harvest to sale
Thanks to
QPIF
Sunfresh
AAL
HAL
© The State of Queensland, Department of Employment, Economic Development and Innovation, 2009