UV test for potential contaminant

Seeka Kiwifruit Industries, working in conjunction with Zespri, has led the way in developing a non-invasive UV testing technology to check trays of export kiwifruit potentially affected by contamination.

Seeka is one of a number of Bay of Plenty packhouses supplied by distributor UPNZ with a batch of Plix brand moulded plastic pockets that was found to have been contaminated with lubricant oil by the Chinese manufacturer. Seeka fruit represents less than one-third of the total of 1.7 million trays that have been held, and says it expects to have completed its checks by the end of next week, with teams working 24/7.

"We moved immediately to develop a technology that would allow us to check our fruit, and so far have found a very low ratio of contamination of between 1:8,000 and 1:10,000 trays," said chief executive Michael Franks.

The solution Seeka came up with is the use of an ultra-violet light with a specific frequency, which is shone through the trays from below and fluoresces if it detects contamination. Because the light is damaging to eyes, Seeka has made a special unit that projects the image on to a computer screen for viewing.

Seeka western regional manager Jarrad Bates said the company had tested UV lighting at various frequencies to find the one that worked with the particular contaminant and type of plastic involved.

"It is a very unusual frequency on the light spectrum and we had to import the bulbs from the US," said Mr Bates.

General manager growers Simon Wells said the Seeka team had worked closely with Zespri to ensure the industry export body was comfortable with the test procedure.

Seeka has five assessment lines operating and will be making more UV boxes for use by the industry and Zespri.

"We have made our procedure open to other members of the packhouse industry and a number have come to observe what we have done, but so far as we are aware no one else has developed their own version yet," he said. "Our cleared kiwifruit is now sitting in our cool store and we are waiting for Zespri to give approval for it to be exported."

Zespri spokesman Oliver Broad said the kiwifruit export group was still assessing and analysing before making a final decision. "We have had further lab tests done of the grease and we are waiting on further information and analysis," he said.

"That will help inform our judgement on whether the right option is to test and recheck all the trays and repack and release for export the kiwifruit that is unaffected, or alternatively dispose of all the product. The final decision has not yet been made on whether, with a testing procedure like the one Seeka has developed with our co-operation, we can go ahead and release any unaffected kiwifruit."

The impact:

* Zespri has held up a total 1.7 million trays of kiwifruit while it investigates fruit potentially contaminated by lubricant found on trays made by a Chinese manufacturer.