After years of research and evaluation, “Arctic” apples and “Innate” potatoes are available on grocery store shelves. Both foods have been genetically modified to resist browning when sliced.

Browning occurs when enzymes called polyphenol oxidases (PPOs) react with antioxidant chemicals called phenols. Normally, phenols and PPOs are kept separate inside cells, but when the fruit is bruised, sliced or bitten, the compounds mix and browning occurs.

No more browning: How they did it with RNAi

Basically, much like turning off a light switch, scientists are able to use a process called RNA interference, or RNAi, to selectively silence or “turn off” the activity of a single gene. In this case, the developers of Arctic apples and Innate potatoes use RNA interference technology to suppress the activity of PPO encoding genes, so the browning reaction does not occur.

RNA molecules are copied from the DNA instructions found inside cells. There are several forms of RNA, including messenger RNA which provides information to produce proteins. In the 1990s, researchers noted a type of RNA composed of small double-stranded molecules. These fragments could effectively stop protein production by coordinating the destruction of the single stranded messenger RNA. In other words, the double stranded RNA interfered with the messenger RNA, effectively silencing the activity of the gene.

In the case of the nonbrowning apples and potatoes, researchers created a short synthetic double-stranded RNA molecule that binds and degrades the messenger RNA that codes for PPOs. This means the foods are less susceptible to darkening and bruising. Even though the products resist browning, they still decompose over time.

Approved and on shelves – just as nutritious

The technology to modify browning-resistant potatoes was developed by Australian researchers who licensed it to a Canadian company for use in apples. Both products underwent years of testing and evaluation before receiving U.S. Department of Agriculture, Food and Drug Administration and Environmental Protection Agency approval prior to appearing in stores in 2017. The review of both products found they are nutritionally equivalent to traditional apples or potatoes and have no elevated health or environmental risks. The review process included multiple opportunities for public comment.

While the products have received criticism, the Arctic apple company argues that nonbrowning apples will reduce the use of antibrowning chemicals commonly sprayed on sliced apples before packaging. Simplot, the company that produces the Innate potato estimates their product could eliminate the more than one billion pounds of bruised potatoes that are wasted each year.

Nonbrowning Golden Delicious apples were introduced to market in Fall 2017. Recently, it was announced that nonbrowning Granny Smith apples will be available in 2018, followed by Fuji apples in 2019. The nonbrowning potatoes include Ranger Russet, Russet Burbank and Atlantic varieties.

To schedule a media interview with Dr. Neil Lamb or to invite him to speak at an event or conference, please contact Margetta Thomas by email at mthomas@hudsonalpha.org or by phone: Office (256) 327-0425 | Cell (256) 937-8210