A leading potato-crisp maker will get more chip from its spuds because of testing part-funded by Technology New Zealand.
Kiwis spend more than $72 million a year on their potato chips, and growers produce thousands of tonnes of potatoes to
feed chip eaters. Research by Pukekohe potato grower Chapman Onion Exports, Bluebird Foods, and Crop & Food Research has looked at how to cut seasonal wastage of potatoes – destined to be chipped.
Bryce Howard, Bluebird Foods' technical manager, says a significant amount of chips has had to be rejected because of
what is known as black chip. This does not appeal to the consumer.
"It's to do with how much sugar is in the potato," he says. "Sugars in potatoes caramelise during crisp-cooking. That's
because during storage, sugars in potatoes increase. It's part of the ageing process. Cold-storage minimises it, but
that can also cause sugars to increase.
"So part of what we've been doing is seeing how warming and reconditioning potatoes during storage can reduce sugar.
We've been trying to find the best conditions that keep the sugar in balance."
Until now the industry has relied on test strips similar to those used by diabetics to measure sugar in urine. It has
not been accurate.
With funding from Technology New Zealand – an arm of the Foundation for Research, Science and Technology – a better way
of assessing the condition of stored potatoes has been found.
Crop & Food scientists have come up with a hand-held device similar to a spectrophotometer used in medical research to scan
potatoes and assess their state.
"Before, we could look at a stack of potatoes and not be sure whether they would keep," Mr Howard says. "When you're
dealing with thousands of tonnes of potatoes, that becomes an important cost factor. Wastage is huge.
"Now we have a way of assessing potatoes and deciding whether they should be used now or whether they can stay stored
for a couple of months."
Tests are continuing and Bluebird is changing over to using the patent-protected tool for future production.
Technology New Zealand acting manager Nigel Metge says wastage is a huge cost on any business. "Anything that reduces or
eliminates that, cuts costs and improves the process has got to be worth investing in."
Mr Howard says the project would probably not have gone ahead without Technology New Zealand funding. "We work a lot
with Chapmans anyway, and Crop & Food had the scientists available. So it was win-win all round."