NZ: Avocado growers hope science will expand export markets
Dynamic controlled atmosphere (DCA) hibernates fruit inside a container by monitoring the oxygen level and keeping it just above the point where chlorophyll does not fluoresce.
New Zealand Avocado Growers’ Association chief executive Jen Scoular, told www.freshfruitportal.com the technology was trialed at a commercial level last December when avocados were sent to France with positive results.
"The first container went and obviously there’s a risk attached because you have commercially viable fruit in the container," says Scoular.
"We had an exporter, Just Avocados, that had a market demand for New Zealand avocados in France and so it went over to arrive just before New Year."
The New Zealand Avocado Industry Council, the Agricultural and Marketing Research and Development Trust, and Plant & Food Research have been working to develop DCA for industry use since 2003.
Plant & Food Protection Bioprotection business manager Declan Graham, said what was used in the December trial was not truly DCA.
"You want to maintain the low oxygen, low carbon dioxide level, so you can’t do that inside a shipping container – there is no facility to be able to do that."
Scientists instead used about six avocados from the total shipment as a proxy DCA to determine the appropriate level of oxygen and carbon dioxide for that particular fruit.
"Once we determined what that level was going to be, we set the container accordingly. We referred to it as programmed DCA," says Graham.
Delayed for a week and a half, the shipment arrived in France 50 days after harvest.
Scientists believe 40-45 days in shipment time is the ideal amount for fruit sent using the technology.
"If you put avocados in normal controlled atmosphere, the avocados will take about seven days to ripen," explains Graham.
"When you use dynamic controlled atmosphere, it only takes about three days for the fruit to ripen. The shorter the period of time it takes for the fruit to ripen the less chance there is of rots."
Finding the right fruit for DCA
The trial included fruit from three different orchards, only two of which had positive results.
"It was to do with the fact that it was beyond the point where it should have been harvested," he says.
"On a lot of occasions we’ve been able to recognize that, but there are instances where for some reason the fruit is not ready."
He says the next step will be to give orchards or exporters information on the attributes of a fruit that can be exported over long distances.
Just Avocados logistics manager for the trial’s exporter Tony Sinkovich, wants to test different harvests to see what will work well with DCA.
"Fruit in October behaves totally differently than fruit in December and also fruit in January," he says.
"I’m confident that the systems are ideal, but I’d like to see what it does at various stages in a season and see how other fruit behaves on arrival then."
Just Avocados sent a second trial to France in January, this time with fruit from six different orchards. The shipment is due to outturn around mid-March.
In addition to trialing different types of avocados, Scoular hopes to test the technology outside of just shipping containers.
"We haven’t yet looked to see if we could actually store fruit on shore for a couple of weeks before it goes off to Australia.
"I think it really opens up for us a lot of possibilities and opportunities for a large volume of fruit coming on stream."
Potential for the industry
Despite work still to be done to make sure DCA works at a commercially viable level, Sinkovich is confident there are new export markets on the horizon.
"This industry is looking for something that can take us away from the Pacific Rim," he says. "Sometimes we need to test our boundaries, and this technology is ideal for it."
Of the 3.8 million trays of avocados exported from New Zealand this past season, about 3 million went to Australia, 400,000 to Japan and 200,000 to the United States. The rest went to smaller markets.
This year, 75% of New Zealand avocado exports will go to Australia. Scoular expects supply volumes to reach 10-12 million trays in the next five to 10 years, creating even more need for distant markets.
"As our volumes increase China and India are certainly markets we want to explore," says Scoular. "To get to India it is a four-week shipment time, so we do need DCA to get to India.
"Russia’s also a country that we have had interest from. It’s all about where the demand from our customers is."
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Photo: Avocado Growers Association and Industry Council