CSIRO data used for ‘non-brown­ing’ ap­ple

CSIRO re­search leads to non-brown­ing ap­ples

The Northern Star - Northern New South Wales Rural Weekly - - Front Page -

RE­SEARCH by Aus­tralia’s peak sci­en­tific body, the CSIRO, has led to the pro­duc­tion of ap­ples that will not turn brown af­ter they have been cut.

The find­ings have been taken into the North Amer­i­can mar­ket­place with a va­ri­ety named Arc­tic Golden ap­ples, with fur­ther va­ri­eties ex­pected in com­ing years. They will also have an im­pact on the amount of “im­per­fect” food be­ing thrown out.

The non-brown­ing tech­nol­ogy also has the po­ten­tial to re­duce waste in pota­toes and other im­por­tant crops – such as beans, let­tuce and grapes – where pro­duce with small in­juries could still be sold.

Ap­ples turn brown when they are cut thanks to a nat­u­rally oc­cur­ring en­zyme called polyphe­nol ox­i­dase (PPO). This en­zyme is re­leased when the fruit’s cells are “bro­ken”. It re­acts with other parts of fruit cells, turn­ing the fruit brown. It can’t be re­versed and often fruit is thrown away.

The PPO en­zyme can be de­stroyed through cook­ing or re­duced by cov­er­ing the fruit. The ascor­bic acid in lemons will also de­lay the PPO en­zyme re­ac­tion.

The CSIRO re­ports that it took a dif­fer­ent ap­proach. First, its re­searchers iso­lated the genes that en­code the PPO en­zyme, then they con­structed an anti-PPO gene and in­serted it to block pro­duc­tion of the en­zyme.

Keep­ing food fresher for longer is a ma­jor tac­tic in the war against waste, which sees more than four mil­lion tonnes of pro­duce thrown out each year – about $1000 for the av­er­age Aus­tralian house­hold.

This month, a spe­cial kind of ap­ple slice will go on sale at some US su­per­mar­kets.

The Arc­tic ap­ples were de­vel­oped by Cana­dian biotech com­pany Okana­gan Spe­cialty Fruits, whose founder, Neal Carter, be­gan work­ing on the ap­ples in the mid-1990s.

“I came across re­search from CSIRO that had man­aged to ‘turn off’ brown­ing in

❝grower, Asa

I was aware ap­ple con­sump­tion had been de­clin­ing...

— Neal Carter

pota­toes,” Mr Carter said. “As an ap­ple grower, I was very aware that ap­ple con­sump­tion had been de­clin­ing for decades while obe­sity rates had si­mul­ta­ne­ously been sharply ris­ing. My wife and I felt that we could help boost ap­ple con­sump­tion through a sim­i­lar biotech ap­proach.”

The CSIRO’s Ian Dry and Si­mon Robin­son worked on the project in the 1990s.

“We heard about a nat­u­rally oc­cur­ring sul­tana grapevine mu­tant that pro­duced sul­tanas that were light golden in colour in­stead of dark brown and we tried to find out why,” Dr Dry said.

“We dis­cov­ered the sul­tana was light in colour be­cause of a mu­ta­tion in the grape PPO gene.

“It was then that we re­alised the po­ten­tial of this dis­cov­ery to be ap­plied to other fruits and veg­eta­bles. We tested anti-PPO tech­nol­ogy on pota­toes and man­aged to pro­duce Aus­tralia’s first non-brown­ing potato.”

The anti-PPO gene in the ap­ples does not come from an­other species. It is made from DNA se­quences from four of the ap­ple’s own genes, and in­ser­tion of this anti-PPO gene is aided by com­monly re­lied upon biotech tools.

PHOTO: CONTRIBUTED

FRESH: But cut them and they will go brown. Sci­ence is help­ing save such fruit from be­ing wasted.

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