Fungal Fruit and Nasty Nuts: 

Dirty Snacks That Can Make you Sick

article top

Dried fruit and nuts have earned their reputation as healthy, nourishing foods that make for a great snack. They are convenient to carry and they don’t need preparation, so you can eat them straight away whenever you are hungry. And since they are dry, they are neat to eat and won’t dirty your hands.

The question is, how dirty and contaminated is the snack. You wash your hands before eating. Should you also wash the snack?


It’s long been known that fruits, vegetables, and nuts from the store may be contaminated with toxic chemicals, including heavy metals, herbicides, pesticides, and preservatives. They may also harbor bacteria, fungi, insects and their waste products, and can be dusted with dirt, ash, soot, and other environmental contaminants. Some of the toxins in dried fruit and nuts can be lethal, such as aflatoxin. That is why it’s so important to clean food before you consume it. 

However, there are different types of foods, and we have different cleanliness standards and expectations for each one. Some foods we wash before using, and some we don’t.

We don’t clean pre-packaged, prepared foods.  

We assume, and hope, that the food production plant is hygienically operated under strict food safety standards. We have become accustomed to opening a package and immediately consuming the contents without any further need or concern for cleaning that product. This is how we treat frozen dinners and baked goods. Just open the package, maybe heat the contents, and consume. While contamination of the factory can lead to a product recall, we assume consumer protections are in place. 

We do clean agricultural food products, such as fruits and vegetables. 

These products are directly in contact with soil, chemicals, lots of people, machinery, and more. They are exposed to potential contaminants during their production, processing, shipping, storage, and marketing. Everyone knows, for example, to wash potatoes from the grocery store when taking them out of the bag, which may even contain some dirt. You know the potatoes were washed before packaging, but you wash them again, even if they look clean. 

But then there is a category of food products which you don’t clean, but should. 

That includes dried fruit and cracked nuts, which are semi-processed agricultural products that may be contaminated and needing cleaning. High on the list are raisins, which have been successfully marketed as a snack food eaten right out of the box, like you would eat a candy or other cooked, prepared product. You assume each piece of candy in the box is clean, so you assume each raisin in the box is clean, as well. 

Ironically, when people buy grapes, they wash them before eating. But when they buy dried grapes, or raisins, they don’t wash them, as though the drying process removed contaminants, which it does not.  These fruits, when fresh, are usually washed before setting them to dry, but they are not typically washed after the potentially-dirty drying process, since washing them makes them wet again and attracts mold.

Even if washed after drying, these dried fruits typically have wrinkles in their skins, which are difficult to clean and are effective at trapping dirt and other contaminants. In addition to these crevices in the skin, there may be sugar on the dried fruit skin that can gathering moisture, which makes dirt and other nasty stuff stick better. Moisture also promotes bacteria, mold, and yeast growth. 

You literally don’t know who or what has touched or contaminated the date, fig, apricot, or handful of raisins that you just put in your mouth. When you consider that lots of dried fruit is imported from less developed countries with lower standards of hygiene and food safety than in the US, it’s enough to make you sick.

But how do you clean dried fruit and nuts? Here are some tips.

  1. Soak the fruit to reduce wrinkling and facilitate cleaning. Soak them in warm water for a few minutes. If you just run water over raisons, for example, the water will not get into the crevices, so you need to first let the raisons soak in warm water to swell the raison, which will reduce the wrinkling and make it easier to clean. The same would go for other dried fruits with wrinkled skin. Of course, nuts also need to be rinsed before using.
  2. Once the skin of the fruit has expanded, mechanically rub the fruit in a bowl of fresh water to clean the surface. Do the same with nuts.
  3. Dry the fruit and nuts and store them in a cool, dark place in a sealed container.
  4. Make your own snacks with the clean, dried fruit and nuts. Just put them in a convenient, toxic-free container, and you can rest assured that your snack will be free of contaminants.
  5. Avoid bulk dried fruit and nuts. These are probably more contaminated than pre-packaged fruit and nuts from trusted food producers. However, even those should be washed, since oxidation and mold formation can happen even in cleaned products due to storage and handling. 
  6. When buying packaged dried fruit, look for additives, such as sulfur dioxide, which may be a problem for allergic individuals. Also look for the quality of the fruit or nut. Are there discolored or rotten pieces in the package? How fresh does it look? Is there dust in the nut packages, which may potentially be old and moldy particles? When you open the package, does it smell right? If in doubt, throw it out.
  7. Consider that dried fruit does not need to be eaten dried. Drying is a storage method for fruit, and helps make the food available off-season. This doesn’t mean you have to eat it dried. Rehydrating the fruit to wash it and then cook with it is a great way to include these nutritious foods in your diet. 

In summary, treat dried fruit and nuts as you would treat other produce you buy in the store. Just because it comes dried does not mean it is clean and ready for consumption. Assume all bulk fruit and nuts, and many packaged ones as well, need cleaning before use.




Leave a Reply