As you’ve likely heard, Arctic Apples are genetically engineered nonbrowning apples that are currently undergoing review in both Canada and the US. We invited you to ask your questions in What do you want to know about Arctic® Apples? Those questions and more were answered by Neal Carter, president of Okanagan Specialty Fruits.
1. Can you tell us about the Arctic® Apple trait? Why did you choose the name “Arctic”?
We chose the name Arctic because “Like the snow-driven landscape for which they are named, the flesh of Arctic® Apples remains pristine and unspoiled.” The nonbrowning trait that separates Arctic Apples from conventional apples comes from their ability to resist enzymatic browning. Typically, when a conventional apple is damaged, it will produce an enzyme called polyphenol oxidase (PPO) which is responsible for the oxidation of the apple’s flesh. This causes an unappealing brown color and loss of texture, flavor, and nutrients. Arctic Apples have the gene sequences responsible for PPO production “silenced”, explained in more detail here. Arctic fruits contain no proteins that aren’t in all apples, and are the same as other apples until they are bruised, bitten or cut – that’s when the difference becomes clear!
2. What color is Arctic® Apple cider?
Since Arctic Apples are nonbrowning, so is their juice! As a result, pure Arctic Apple juice will be much closer to the apple’s true color (see picture). While most apple juice today is a collection of different varieties, Arctic Apples create an opportunityto market variety-specific juices, each with their own unique flavor and color.
3. Can Arctic® Apples be baked or cooked like conventional apples? Do they look different after cooking compared to other apples?
Arctic Apples can certainly be baked and cooked just like conventional apples – they just won’t look as brown by the end! For example, an apple brown betty might now be better described as an “apple no-brown betty” (credit to @SkepticalVegan for that name)! One has to remember however, that some of the browning in cooking apples is from the carmelization of the sugars, and this will still take place. In addition, when cooking Arctic Apples you don’t need to race against time to get your cooking done before they brown and lose their eye-appeal (see our Arctic Apple pie blog). Arctic Apples provide many new product development opportunities for the fresh and processed industry alike.
4. One reader prepares food for children at a daycare each morning to be eaten later in the day. The apples always brown, and they have trouble getting the kids to eat them. How long do the apples last when they are cut?
This is a perfect example of one of the key utilities of Arctic Apples! Parents (and daycare workers) can cut up apples for their kids’ lunches and they will look and taste like they were freshly cut when it’s lunchtime. What’s more, sliced apples can be readied for snacking throughout the day like never before! Arctic Apples won’t brown nearly as quickly as conventional apples, but can still dry out if left out in the open for an extended period of time. Sliced Arctic Apples can maintain their natural flesh color and fresh in a zip-top bag in the fridge for over two weeks. When they finally do start to brown, it will be from naturally-occurring bacterial or fungi spoilage that eventually cause browning.
5. What sorts of efforts have been made to reduce browning through conventional breeding? What barriers are there if any to creating a very low browning or nonbrowning apple with breeding? Cortland and Granny Smith are said to have reduced browning compared to other apples, how do they compare to Arctic® Apples?
There are certainly some apple varieties developed through conventional breeding that are low-browning, but only Arctics are truly nonbrowning. The length of time that it takes different apple varieties to brown is based on a number of factors. According to a report from Agri-Food Canada, which explores the browning rate of some of the most browning-resistant varieties, “the rate and intensity of enzymatic browning depend on PPO concentration, polyphenolic substrate content, oxygen availability, pH value and temperature.” While low-browning varieties take much longer to brown than many common varieties, even the Courtland, which is the most resistant of all, will generally experience “moderate browning” within 24hrs of being sliced.
6. How does the nonbrowning trait stack up against other methods to reduce browning like lemon juice?
Similar to low-browning varieties, certain treatments such as lemon juice can reduce enzymatic browning, but do not truly stop it like Arctic Apples. Since the browning process requires oxygen, the use of antioxidant treatments such as solutions with plenty of Vitamin C (like lemon juice) can create a barrier between the cut apple cells and the air. Unfortunately, these treatments can alter the taste and texture of the apple, and for commercial freshcut products, using solutions like these can double production costs. With Arctic Apples, costly antioxidant solutions that can create an off-taste are unnecessary, making them ideally suited for the freshcut market. Over 40% of U.S. consumers’ food budget is spent on food made and eaten away from home and apples are the number one requested packaged produce item; so the need is there and Arctic Apples are the solution!
7. How many apples are lost during and after harvest due to bruising? Would Arctic® Apples help to decrease food waste?
It is difficult to know the exact number of apples lost or culled each year due to bruising, but it is certainly substantial. It has been reported that “even under the best conditions, 10 percent or more of the crop will be culls; sometimes…as high as 50 percent” and this, coupled with the fact that the U.S. alone produces around 200 million bushels of apples annually, mean that Arctic Apples can prevent a lot of food from being wasted! Not every cull is due to superficial browning, but it certainly represents a large percentage of the millions of bushels culled each year, to say nothing of all the fruit wasted in grocery stores or at home due to browning. For more on this issue, see a great article by the president of Ag-West Bio titled “Okanagan Specialty Fruits technology reduces food waste, offers market options.”
8.Do Arctic® Apples spoil faster or slower than regular apples? Does the non-browning trait hide spoilage, or does it do the opposite?
That’s a great question and one we get asked a lot. In fact, Arctic Apples do not hide spoilage at all – they help show it! Enzymatic browning, which Arctic Apples prevent, is much different than the biotic decomposition that occurs when a fruit is too old or has significant damage. Arctic Apples will not undergo the browning reaction when they are superficially damaged, such as through finger bruising, bin rubs, or simply being sliced. So, if you see an Arctic Apple that looks damaged, you know it’s not just a cosmetic issue. This is one of the reasons so many perfectly good apples get culled and thrown away; most consumers won’t buy an apple if any flaws are visible at all!
9. What is the current regulatory status of the Arctic® Apple in the US and Canada?
We are pleased to report significant progress has been made toward deregulation in both countries. In Canada, the Canadian Food Inspection Agency (CFIA) posted our Notice of Submission in early May, which allowed the public to comment on our submission for the “unconfined environmental release” of Arctic Apples. This comment period concluded July 3, and we are now awaiting word from the CFIA as they continue to review our submission and the comments they received (see here for one great example). In the U.S., the Animal and Plant Health Inspection Service has posted our 163 page petition for nonregulated status and they are asking for input from the U.S. public (see here for how to submit comments). We expect the deregulation processes, described in detail here (Canada) and here (U.S.), will conclude in 2013. We are planning to have trees available to commercial nurseries and growers soon, with fruit beginning to arrive in North American grocery stores in 2014 and 2015.
10. Will Arctic® Apple trees only be sold wholesale to commercial growers, or will they be licensed to nurseries for home gardeners to grow? Plenty of patented varieties like SunCrisp and SnowSweet can be bought for home growing, so after deregulation is complete, would that be something the company would be interested in doing?
Our focus is with commercial growers and nurseries; though making Arctic Apples available for home gardeners is certainly something that may be considered, it’s not in our current plans. As mentioned, it will still be a couple of years before Arctic Apples make it to market. Since growers typically replant 3-5 percent of their overall acreage each year, and it takes 3-4 years for those trees to bear commercial fruit, Arctic fruit will appear in the consumer marketplace slowly and gradually.
11. Could you characterize the public response to these apples? Have you conducted, or plan to conduct any research on consumer acceptance or appeal? What do farmers think about them?
While any product that is created through biotechnology will split public opinion to a certain degree, much of the response has been extremely positive. We completed a thorough consumer survey in Oct. 2011 that showed that the number of respondents who think biotech-produced nonbrowning apples are a good idea is well over double the number who think it’s a bad one. We also found the more consumers learn about Arctic Apples, the keener they are to buy them! Additionally, we surveyed a number of leading apple industry executives in 2006/07 and 76% were interested in Arctic Apples (we have tweeted many of their comments, check them out). We have also had many growers approach us wanting to get involved or to be kept in consideration for when Arctic Apples become deregulated. And, of course, we are largely grower-led and grower-funded, so we are confident of Arctic Apples’ value and appeal throughout the supply chain!
12. How much of a concern is cross-pollination and pollen gene flow?
Cross-pollination (which we discuss here) should not be a significant concern for a few reasons. First, apples are not “weedy” – they don’t escape orchards to grow wild. Secondly, apple blossoms are pollinated by bees, which stay close to the hive (generally within 100m [300ft]) where there is amply food present, such as in an orchard in bloom. According to University of Florida fruit genomics specialist Dr. Kevin Folta, “The fears of issues from cross-pollination are completely baseless to anyone that understands how apples are grown, pollinated and propagated.” Third, our grower stewardship standards will further reduce this already low risk by defining buffer distances between Arctic and other apple orchards. Finally, in the unlikely scenario that cross-pollination did occur, the DNA from the Arctic Apple pollen would be present only in some of the resulting apples’ seeds (which are not consumed or used for propagation), not in the fruit’s skin or flesh.
As apple orchardists, we know that it is a challenge to achieve sufficient pollination for proper fruit production and in addition to the above points, we have results from our field trials that also suggest a low-risk. To evaluate the risk of pollen gene flow from a transgenic apple block we set up an experiment whereby we collected about 50,000 seeds along various transect lines radiating outward from 20 GUS expressing, transgenic test trees for approximately 600ft. Mature fruit was harvested and the seeds collected, germinated and tested for the GUS gene. This data was provided to a mathematics professor and her grad students and they produced two peer reviewed papers that detail pollen movement as predicted by dynamic modelling. Not surprisingly, the pollen doesn’t move very far.
13. Would you consider Arctic® Apples to be cisgenic or transgenic? What T-DNA features are present? Was it developed with RNAi? For each variety, did you have to transform them separately?
For this question and for question #14, we turn to our Research Manager, Dr. John Armstrong: Arctic Apples are transgenic. The T-DNA features include: (i) a sense suppression transgene designed to suppress four members of the apple polyphenol oxidase (PPO) gene family under control of the duplicated-enhancer cauliflower mosaic virus promoter and nopaline synthase terminator, and (ii) a selection marker, neomycin phosphate transferase type II, providing resistance to kanamycin, under control of the nopaline synthase promoter and terminator (you can also read more about this in our site’s FAQ). Each apple cultivar is transformed separately.
It is important to note that testing has shown that the nptII selection marker is not expressed in mature apple fruit, so no NPT protein, nor any other protein not found in all apples, is present in mature Arctic Apple fruit.
RNA Interference (RNAi) is a natural method for controlling gene expression in a wide variety of species (Wikipedia has a useful description of RNAi here). We utilized what used to be known as sense suppression or co-suppression to induce the RNAi pathway and down regulate the apple PPO gene family.
14. What types of safety evaluation have been conducted for Arctic® Apples? How do we know what effect they will have on the environment or on human health?
Arctic Apples have been grown and monitored, alongside untransformed control cultivars, in field trials in the major US apple growing regions in the states of Washington and New York since 2003 (WA) and 2005 (NY). The field trials are managed and monitored by professional horticulturists paid by, but not employed by, OSF in a manner consistent with commercial apple cultivation methods, adhering to integrated pest management (IPM) and Good Agricultural Practices (GAP) approaches.
In the field, data for agronomic performance characteristics, including tree height, trunk cross-sectional area, flower clusters, and fruit number at harvest is collected. Data on response to pests and diseases such as scab, mildew, and Fireblight was collected and assessed. Compositional analysis of mature apple fruit was performed by third party laboratories and included the analysis of proximates (e.g. protein, moisture, calories), vitamin C, ORAC and total phenolics. In addition, the amount of NptII protein in field leaf tissue and mature fruit was measured.
This data and its analysis are available in our USDA Petition, but to summarize, in our field trials, the Arctic Apple cultivars grow and behave the same as the conventional parent cultivars from which they are derived. With respect to nutritional composition, Arctic Apples fall within USDA norms for apples and are identical to their parent cultivars, with some notable exceptions. For our nutritional study, apple slices, rather than whole apples, were sent from our field trials to the third party laboratories for analysis. Apple slices were packed on ice and couriered overnight, meaning that they were processed by the third party labs within <24 hours of slicing. Arctic Apple maintained the vitamin C, ORAC and total phenolic levels indicated by the USDA Nutrient library, whereas our control apples suffered significant (approximately 80%) loss of these nutrients. These results were significant and consistent for both the Arctic Granny and Arctic Golden cultivars and in both field trials. This information has become a focal point for future Arctic Apple research. In the petition document, we provide a narrative on why this unexpected benefit may have occurred.