How do New Zealand apples stay crisp from tree to table?

South African Nicolette Neiman came to Hawke’s Bay from Johannesburg and now puts her skills to use ensuring one of New Zealand’s most valuable export crops lasts the distance.

It’s all about ethylene, she told RNZ Podcast Here and Now.

We lose a big chunk of our fresh food before it reaches consumers, Neiman explains.

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“It's extremely important worldwide. We lose about a third of our fresh produce before it reaches somebody's tummy, I could say.”

Left up to nature, a single hormone signals to fruit to start ripening, softening and eventually rotting – ethylene. So, preventing ethylene from doing its job is a big deal, she says.

Though she now works with apples in Hawke’s Bay, it all began with tomatoes and plant biotech a world away in South Africa.

“I did my PhD on tomatoes, and I did a bit of work on a small chilli pepper. We worked a lot with indigenous medicinal plants or plants that are commonly seen as weeds, and that's where I ended up, on mine dumps.

“So, we could see these plants, what chemicals that could be useful, could we find in those plants that could make them commercially viable.

“And then we moved here, and Hawke's Bay is so far removed from a city of six million people.”

So post-harvest how does science deter ethylene from doing its work? A gas called 1-methylcyclopropene (1-MCP) is the answer.

“The 1-MCP molecule blocks where ethylene would have gone and sat and triggered the chemical changes in the apples.”

It is applied as a gas, she says.

“All the apples as they've been picked will go into the room, be cooled down and then the room is sealed, and they release this gas into the atmosphere. And it stays sealed up for 24 hours.

“It's usually the normal treatment time. And then they open it up and vent the room out and the treatment is done.”

In nature, ethylene serves a valuable purpose, she says.

“If the fruit didn't decompose, you would have apples from 10 years ago lying under the trees.”

Lessons learned in Hawke’s Bay benefit growers throughout the world, she says.

“So we know, for instance, temperature is extremely important. Where you have to sanitise to make sure you don't carry diseases, bacteria, insects, other types of parasites to people.

“And then that technology can be used in other countries where they do not have the capacity to do the research or where they don't have the technology or the equipment to do these things.”

Here Now presented by Kadambari Gladding is about the journeys people make to New Zealand, their identities and perspectives, all of which shape their life here.