If you’re partial to citrus fruits, you may wish take note of a health warning from nutrition expert Jenny Tschiesche about the potential risks associated with their zest.
The Sunday Times number one bestseller and author of several cookbooks shared her advice on TikTok. “Do check the labels on your easy peelers to see what they have been treated with,” she advised in a video, brandishing a bag of supermarket-bought mandarins from South Africa.
“Don’t grate the zest into your food and certainly don’t cook the whole fruit as you might be surprised by what they’ve been treated with.” Jenny went on to stress: “Citrus zest isn’t always safe to eat! Many supermarket mandarins, and tangerines are treated with surface fungicides to keep them fresh. These ones I found had been treated with imazalil, 2, 4D [2,4-dichlorophenoxyacetic acid], pyrimethanil, thiabendazole, fludioxonil and azoxystrobin.”
Jenny continued to caution that regular or high concentration consumption of such chemicals can affect your health in various ways. “Imazalil and thiabendazole can affect the liver and endocrine system,” she pointed out.
“Fludioxonil and pyrimethanil may cause irritation or metabolic effects. While 2,4-D has been linked to possible hormonal and neurological effects.”
Fortunately, Jenny added that regulatory bodies including EFSA and FDA set maximum residue limits (MRLs), which are designed to keep these residues far below harmful levels in normal consumption. However, she further explained: “Yet, the presumption is that you’ll peel and eat the fruit. So don’t use the zest nor eat the peel of those treated with these substances unless you wash and scrub thoroughly first.”
Jenny concluded with some additional advice:
- Peel before eating
- Wash and scrub well if using the zest
- Or choose organic fruit
One TikTok user queried in response: “What if you need zest, what do you get instead?”.
To which Jenny clarified: “You can either choose to wash them thoroughly or even better go for organic which will have less and in some cases no fungicides.”
Another person quipped: “I laughed out loud at option number one being peel before eating. Who’s not doing that already?” Jenny replied by pointing out: “Actually… there are cake recipes that require you to cook the whole fruit with peel then blend. Grated zest – added to porridge or bakes – is also common.”
Meanwhile, Pesticide Action Network UK also advised: “The government’s testing scheme tends to show citrus fruit as having the highest residues. For example, in 2021 100% of grapefruits tested contained pesticide cocktails. This is often because of its peel – fruit such as oranges and lemons, will show higher residues than are actually being consumed.”
The organisation issued a warning: “Having said that, people are increasingly using the zest of citrus fruits. In addition, handling of fruit covered in fungicides (which are used to prevent food rotting) can mean dermal absorption (i.e. through the skin) is a problem, particularly for children.”