Imagine slicing up an apple for a salad without any concern that it will turn brown. The Arctic Apple is a genetically-engineered fruit that doesn’t discolor when the flesh is exposed. But the apple industry is opposed to the Arctic Apple, citing consumer fear of GMO foods.
Why apples turn brown
Have you ever wondered why sliced up apples turn brown so quickly? When an apple is cut or bruised, oxygen is introduced into the flesh of the fruit. The exposure causes an enzyme called polyphenol oxidase (PPO) to rapidly oxidize phenolic compounds in apple tissue into o-quinones. O-quinones react to form proteins that produce the brown color.
Coating freshly cut apples in sugar or syrup can reduce oxygen diffusion and slow the browning reaction. Coating apple slices with lemon or pineapple juices can also slow enzymatic browning. Both acidic fruit juices lower the pH and cause PPO to become less active.
Turning off polyphenol oxidase
Okanogan Specialty Fruits, a grower in British Columbia, Canada is applying for regulatory approval of genetically modified apple trees that produce Golden Delicious and Granny Smith varieties of the Arctic Apple. Arctic Apples contain a synthetic gene that sharply reduces production of PPO. The modified gene contains DNA sequences from the apple’s own genes that act to turn of the PPO gene.
Company president Neal Carter told the New York Times that the nonbrowning apples could improve industry sales, much like baby carrots did for carrot growers. He also said that growers would have fewer apples rejected by supermarkets because of bruising.
Apple industry worries about GMO backlash
The Arctic Apple has the industry worried. The U.S. Apple Association is opposed to the free and open planting of Arctic Apple trees. In a letter responding to a public comment request from the USDA on the Arctic Apple, U.S. Apple said “consumers like their apples and are not calling for these new ‘nonbrowning’ cultivars.” The association also said, however, that its position “is not based on any question about human health or safety.”
Some apple industry executives say if the Arctic Apple is approved, countries that buy American apples may be unsure which apples are genetically engineered and go elsewhere. Opposition to GMO foods is strong in Europe, but reactions are mixed in North America, where more than 70 percent of the American apple crop is sold.
A 2011 survey commissioned by Okanagan Specialty Fruits that nearly 60 percent of American apple eaters were somewhat or extremely likely to buy the Arctic Apples. However, a more recent survey commissioned by the British Columbia Fruit Growers’ Association found nearly 70 percent of Canadians opposed to approval of the apple.
Full speed ahead
Genetically engineered foods do not require FDA approval. Okanagan Specialty Fruits has voluntarily submitted data for review. Meantime, a major grower in Washington state has already planted eight acres of Arctic Apples to be ready to hit the ground running once regulatory approval is obtained.
Source: New York Times, The Packer, Scientific American