Apples - To Brown or Not To Brown

Yet another interesting story from NPR. This one is about genetically modified apples. A company in Canada called Okanagan Specialty Fruits has designed an apple they call "Arctic Apple." It will not brown, because they have silenced certain genes in the apples responsible for the browning reaction.
This is pretty fascinating to me. As a food scientist, the browning apple is a classic science experiment that I love to share with kids. Everyone knows that when you cut an apple it will eventually begin to turn brown. Every slow-eating kid has turned up their nose, and every mom has replied in exasperation, "There's nothing wrong with that apple- just finish eating it!" Or maybe it's just me.
The reason that the apple turns brown is not because it is rotting or spoiling. It is an enzymatic reaction. There is an enzyme in apples (and other fruits) called polyphenol oxidase (PPO). This enzyme is normally happily contained in plant cells along with polyphenol compounds. You may have heard about the antioxidant benefits of polyphenols in chocolate and grapes (red wine). Well, lots of plants contain polyphenolic compounds, including apples.
When you bite or cut or drop the fruit, you are bursting open plant cells and their insides become exposed to oxygen. The PPO enzyme allows the reaction of oxygen and the polyphenol compounds that are found in fruits. And the compounds that result from this reaction are a brown color.
There are different methods of reducing this enzymatic reaction. Lowering the pH causes the enzyme to be less effective. That's why you will often find that ascorbic acid (Vitamin C) has been added to the little packets of sliced apples you can get in many fast food kids meals these days. Lots of cookbooks suggest adding lemon juice or lemon lime soda as well, though Vit C is more effective. Another method is to keep oxygen away from the cut fruit by simply soaking in water. And heat is a sure fire way to inactive the enzyme.

Now that you've had your science lesson for the day...
time to address the real reason for the story.

What is the role of genetic modification in our foods? Where is the line and how do we determine where that line should be? Is there really any difference between using this technology in our fresh fruits and vegetables than in field corn and soybeans? Should we use this technology only when it is helping to increase yield to feed the billions of people in this world- or is it OK to use it to make our food look or taste more like we want it to? We've been using traditional "non-laboratory" genetic methods to make hybrids that behave like we desire for many, many years.
I certainly don't have all the answers, but we need to all be thinking about these questions. Don't be afraid to engage in dialogue about these topics. One of the problems with these GMO discussions is that they often involve big long words that the general population does not understand. And the most common result of ignorance is fear. When technology development begins to outpace our ability to have open discussions about the possible benefits and consequences of that technology, it is easy to blame the technology for moving too fast. But maybe it is our responsibility to pick up the pace with our communication too?



From Okanagan Specialty Fruits website