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How Non-Browning Apples are Different from Other GM Foods

By Edited May 29, 2014 4 14

Granny Smith Apple

 

Why Apples Turn Brown

Apples have a tendency to turn brown when they are peeled, cut, or bruised in transport. You probably know this is a result of oxidation. When plant tissues come into contact with oxygen in the air a chemical reaction changes them, much the same way oxygen exposure causes rust in some metals.

What's happening is that polyphenolic compounds – chemicals responsible for the colour and taste of the apple – react with oxygen. This reaction starts because of an enzyme called polyphenol oxidase, or PPO, which was first discovered in mushrooms. It is also present in other fruits and vegetables like bananas, grapes, pears, and potatoes.

 

Protective Mechanism

Enzymatic browning starts when the flesh of the apple is damaged in any way. Normally the PPO and the polyphenols are kept separate, but peeling, biting into, slicing, or bruising an apple brings the two types of chemicals together and starts the browning reaction. The result of the reaction is melanins, the very same compounds that are responsible for tanning when our unprotected skin is exposed to the sun.

Melanins are present in a number of plants and animals, and are associated with a number of protective responses. Melanin can form a barrier to prevent the spread of damage or infection from one part of the organism to another. It also helps to protect both plants and animals from adverse climatic conditions, and viral and microbial infections.

 

Gene Silencing: The Benefits of Switching Off PPO

A recent article on genetically modified foods called my attention to the development of non-browning apples in my home province of British Columbia. Canadian biotechnology company called Okanagan Specialty Fruits (OSF) has licensed a technology that switches PPO off to eliminate enzymatic browning. First developed in Australia for application in potatoes, OSF has learned to use the process to eliminate oxidative browning in its genetically modified (GM) apples. Suppression of the PPO leaves important polyphenols intact, but eliminates browning of the apple when its flesh is exposed to the air.

OSF founder Neal Carter says he was inspired by the baby-cut carrot market. Despite the overall increase in consumption of fruits and vegetables, fewer apples are currently being sold. Carter recognized the benefits of a non-browning apple for the fresh-cut market, and hopes this will revive consumer interest in eating apples. The absence of browning will also reduce the loss of fruits damaged during picking and transport, which he sees as a significant benefit for fruit growers and packers.

 

 

No Chemicals Required – Well, Kind Of

One of the biggest concerns with other genetically modified foods is the heavy reliance on pesticides and other chemicals. Monsanto's Roundup Ready crops are designed to resist the herbicide glyphosate, and assume the use of this chemical to control weeds. By comparison with GM crops already on the market, OSF's non-browning apples – called Arctic apples for their white flesh – do not involve resistance to any sort of pesticide or herbicide. The apples act just like any other fruit trees in the orchard, and do not require application of any chemicals in order to grow.

Another concern with GM crops is the creation of transgenic organisms by extracting genes from one organism – like the Bacillus thuringiensis (Bt) bacterium – and injecting them into the DNA of another organism like corn or cotton. Transgenesis also involves introducing a tracer, often a protein that makes the GM plants resistant to a specific antibiotic. Because only a fraction of the attempts at transgenesis are successful, scientists attach this marker to the gene that produces the desired change in the plant. They can then test all their samples to determine which ones were successfully transformed.

While Arctic apples don't incorporate any DNA from other species to silence POP, they are still transgenic rather than cisgenic (the difference being whether the genetic material introduced is from a completely different organism, or from within the species.) OSF uses the NPTII protein to create seedlings that are resistant to an antibiotic called kanamycin. Tests show that no novel proteins are expressed in the ripe apples, but this could still affect how consumers view the new apples.

 

Basket of Apples

 

Home Grown Business

Unlike the multinational biotech firms responsible for genetically modified corn, soy, cotton or sugar beets, OSF is a small, grower-owned company. Carter and his wife have lived in B.C.'s Okanagan Valley for decades, and are fruit growers themselves. Their vision stems from a concern with the drop in apple sales, and the fact that apple growers in the region are abandoning the fruit for more profitable crops.

BC's apple industry is in crisis. Increased competition from Washington State and lower profits are discouraging enough that the once 20,000 acres of apple orchards in the Okanagan have dwindled down to less than half that. And no wonder, with some varieties actually dragging growers into the red. A group of six or seven varieties that account for more than 40% of apples grown in B.C., actually cost money to grow rather than bringing in a profit.

OSF has targeted four of these varieties for its non-browning apple breeding program. Arctic Granny Smiths and Arctic Golden Delicious apples are currently undergoing the approval process in both the United Sates and Canada. Non-browning versions of the Gala and Fuji are still in the works.

 

Golden Delicious Apples


Respecting the Consumer's Choice

Non-browning Arctic apples will likely take a few years to reach your local grocery store, as OSF is not planning to grow enough of the fruit themselves for commercial distribution. By the time there are enough growers to introduce the fruit commercially, OSF figures they will be the most studied GM food on the market. And they will be labelled!

Out of respect for the consumer's right to choose, Arctic apples will bear the company logo – the snowflake inside a red apple – and will be labelled regardless of any legal requirement to identify them as genetically modified food. Processed foods that contain more than 5% of the fruit will also bear a label. However in foods that have undergone heating that denatures the DNA – like pasteurized apple juice or applesauce – there will be no specific label.

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Comments

May 18, 2014 3:51am
Larah
Very interesting article Kyla, not sure if I'll be interested in eating non browning apples though, like other GM food it seems so unnatural.
May 18, 2014 5:05am
Ruby3881
I'm still on the fence, myself. It does seem unnatural to be messing around with plants at the level of their genes. But we've been making similar changes with traditional plant breeding techniques for generation upon generation. It's a tough call when we're not talking about mass spraying with pesticide, or adding genes from an insect or bacterium to a plant.

We're already consuming GMOs because of the corn, canola and soy that make it into prepared foods. I'd like to say we ought to avoid other GM foods just on principle, but I also wonder if it will make much of a difference.

And I really love the fact that Neal Carter's motivations are coming from a desire to revive apple growing. That, and his willingness to label his apples.
May 18, 2014 8:32pm
LavenderRose
That is really nice that the company is willing to label the apples. I have often wondered about the possibility that GMOs play a role in autoimmune problems, but without those foods being labeled, there is no way to test that theory. You raise an important point. It all might be a matter of degree. My health started going bad in the 80s, right around the time that Monsanto started messing with the corn. And it's continued to snowball from there.
May 19, 2014 6:30am
Ruby3881
I've had a similar experience, Vickie. It's tough to know whether it was the GM foods like corn, because we've been consuming them for years before we really knew it. And in my case I was also taking life-saving medications that had side effects I hadn't been told about.

It's tough, because a lot of times doctors give you the newest medications hoping they'll work better and have fewer drawbacks. But the reason they seem t have so few side effects is these things come up with long term use, and they aren't seen in the drug trials. It takes a decade or more of people using these drugs daily before the list of side effects starts to reflect reality.

Autoimmune stuff could definitely come along with the Roundup Ready GMOs. All that pesticide gets into our soil and water, and we breathe them in from the air. And in the United States, you have hormones and antibiotics being fed to livestock, so that gets into your food too. I'm sure it all plays a role.
May 19, 2014 6:30am
Ruby3881
This comment has been deleted.
May 19, 2014 6:30am
Ruby3881
I've had a similar experience, Vickie. It's tough to know whether it was the GM foods like corn, because we've been consuming them for years before we really knew it. And in my case I was also taking life-saving medications that had side effects I hadn't been told about.

It's tough, because a lot of times doctors give you the newest medications hoping they'll work better and have fewer drawbacks. But the reason they seem t have so few side effects is these things come up with long term use, and they aren't seen in the drug trials. It takes a decade or more of people using these drugs daily before the list of side effects starts to reflect reality.

Autoimmune stuff could definitely come along with the Roundup Ready GMOs. All that pesticide gets into our soil and water, and we breathe them in from the air. And in the United States, you have hormones and antibiotics being fed to livestock, so that gets into your food too. I'm sure it all plays a role.
May 19, 2014 5:24am
shar-On
I can understand the genetic modified part, but I still prefer my own home grown fruit and veg so I know there are no chemicals on mine. rated up
May 19, 2014 6:39am
Ruby3881
I still don't know if I do understand why a lot of the genetically modified foods are being produced, to tell you the truth. It seems like it started with this promise to increase food security. But when these crops become the only ones grown and then they fail, where is the security in that?

I feel we would have been better off to work towards greater biodiversity, so food security wouldn't be drastically impacted if a single type of crop didn't do well one season. The business model used by Monsanto is to convert all the farmers in a given region, and to squeeze out anyone who resists.

I have problems with that sort of bullying, but I also think monoculture of any kind is dangerous. Even if all the crops were grown organically from heirloom seed, it would still be risky.

I'm with you that anyone who can, should be growing their own fruits and vegetables. Nothing is better than fresh from the garden! Thanks for taking the time to read, rate and comment :)
May 19, 2014 5:31am
RoseWrites
Well, apples have taken quite the beating since being labeled as the first one listed on the EWG's (Environmental Working Group's) Dirty Dozen. I'm leery of any genetically modified apples and I feel that this may be a "tough" sell. Just have to wait and see.
May 19, 2014 7:04am
Ruby3881
This is certainly a factor that someone like Neal Carter ought to be looking at, Rose. No matter whether the apples are conventionally grafted or genetically modified, there's an awful lot of pesticide use in the apple growing industry. People want perfect looking apples, and not fruit that is marked from the insects that get to it while it's growing.

There are chemical-free means to control pests in fruit trees. Whole trees can be bagged with something called Kootenay Covers. I'm not sure whether this works with apples but they were designed for cherry trees, which are related. I've also seen a method that involves bagging the individual fruit. The results are astounding! So, there are some methods that growers could be exploring to reduce pesticide use.

I do suspect if the apple didn't get such a bad rap over the pesticides, people would eat more of them. I do think you're right that it will be tough to sell non-browning apples to consumers. It's more likely they'll end up being sold to companies that want to market apple slices. And yes, there will be a market for that! Even though an apple is so easy to eat fresh, there will always be someone claiming it's better if it can be sold already sliced. And there will always be someone who will buy it for the convenience.

So I think we'll be seeing Arctic apples out there. But I do respect that they'll be labelled. Not sure I'll buy them, but I like knowing my choice matters to this company.
May 19, 2014 7:21am
ologsinquito
Very nice, well-researched article. You have a beautiful writing style. I don't like the idea of genetically modified apples, especially because they'll be making their way into processed products.
May 19, 2014 12:01pm
Ruby3881
This comment has been deleted.
May 19, 2014 12:01pm
Ruby3881
Thank you! A compliment on my writing is always a great way to get my work day going :)

I share your concern about the processed foods. What I can tell you is that Arctic apples will be labelled in prepared foods unless they are heated to a temperature that damages the DNA (as in pasteurized juices and applesauce.)

I prefer the fresh apple cider to the sort of apple juice that would be pasteurized, anyway. But it does concern me that this non-browning trait will be a selling point for the apples entering the food supply in places where they won't be labelled. I guess the important thing will be to contact the company that makes the products you use, and ask them if they are using any GM ingredients.

Thanks for taking the time to read and comment!
Jun 3, 2014 3:51am
ladybugblue
Great detailed and well researched article! Thanks!
Jun 3, 2014 3:06pm
Ruby3881
Thanks so much for the compliment! And for stopping by to read and comment :)
Jun 5, 2014 4:29am
beethovenet1031
Good information!
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Bibliography

  1. Joel Brooks "Top five Arctic® apple myths." Arctic Apples. 25/01/2014. 15/05/2014 <Web >
  2. Neal Carter "Key points we like to make about Arctic Apples." Arctic Apples. 23/02/2012. 15/05/2014 <Web >
  3. Anne Casselman "The Business of Breeding B.C. Apples." BC Business. 06/02/2012. 15/05/2014 <Web >
  4. "Enzymatic Browning." Food-Info. 15/05/2014 <Web >
  5. Lynne McLandsborough "Why do apple slices turn brown after being cut?." Scientific American. 30/07/2007. 15/05/2014 <Web >
  6. John Armstrong "Exploring the marker gene used in Arctic® Apples." Arctic Apples. 31/07/2012. 15/05/2014 <Web >

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