The secret life of dehydrated foods

Other than the little boxes of raisins that left you with sticky fingers, dehydrated foods were a scarce commodity when I was a kid. My aunt travelled a lot and always brought home intriguing dried apricots and dates for us, much to our delight!

Healthy Eating

Sonia Chartier

05 May 2017

Today, dried cranberries are in every salad, dehydrated apricots, dates, figs, mangoes and pineapples abound in supermarkets, and fruit leather is a must-have accessory for just about every lunch box. So like us, you might be wondering about the health benefits of these different forms of dried fruits. 

As far back as colonial times, up until fridges became commonplace in homes, a lot of foods were dried so that they, and we, could survive winter. Sun-dried fruits, berries and vegetables provided nutritional variety and prevented scurvy.

But the dried fruits found in supermarkets today are not quite as natural as they used to be.

Most contain added sugar and sulphites to preserve the fruits’ colour. In people who are sensitive to sulphites, they can cause a range of reactions, from simple itchiness to anaphylactic reactions, diarrhea and asthma. Ands once you find out that the dehydration process already locks in both flavour and sugars, you realize that added sugar is completely unnecessary unless the fruit is naturally sour or bitter.

While nutrients are highly concentrated, so are the sugars and calories.

Gram for gram, dried fruits contain three and a half times as much fibre, vitamins and minerals as fresh fruit.  They’re usually richer in polyphenols , antioxidants that promote healthy blood flow and digestion while reducing oxidant stress and the risks of contracting a number of diseases. The flip-side of the coin is that they contain less vitamin C than fresh fruits. 

But while nutrients are highly concentrated, so are the sugars and calories. So go easy: it’s probably not a good idea to wolf down a half-dozen apricots in one go. Once fruits are dried, it’s harder to tell just how much sugar and calories they contain because they’ve shrunk. The sugar content of dried fruits is somewhere between 38% and 68% (or 53% in the case of my apricots).  My dentist also warned me that dried fruits and fruit leathers stick to teeth and promote cavities. If you snack on dried fruits at the office, make a point of keeping a toothbrush there.

Keep in mind that dehydration modifies foods’ chemical composition, which can affect some of their health benefits. That’s precisely why fresh medicinal plants don’t have the same properties as dried plants. For example, fresh ginger contains gingerol, an anti-inflammatory, antioxidant and cancer-fighting compound that is also responsible for ginger’s spiciness. Once dried, gingerol gets converted into shogaol which, despite its somewhat different properties, is currently being studied as a potential treatment for Alzheimer’s disease.  The two are different, but each has its benefits.

Dehydrating foods at home

Are there any big fans of dehydrated foods out there? Well, astronauts certainly are, but they’re definitely not bringing the home-made kind on their trips! The most likely enthusiasts are those really into camping and hiking, organic food basket subscribers and gardeners overwhelmed by their bumper crops.

The big advantage of dehydrated foods is that they’re an economical way to store seasonal fruits and veggies. At farmers’ markets, deliciously fresh produce abounds, much more so than at grocery stores. When you buy a box of peaches, cherries or tomatoes, even if you gorge yourself on them, you probably won’t be able to eat them all before they go bad. By dehydrating them, you can add around a year to their edible lifespan, while saving a bunch of space in your pantry.

This kind of preservation eliminates the risk of contamination because bacteria and moulds can only thrive in moist environments. But be careful not to dehydrate foods that are already mouldy, and don’t try dehydrating fatty foods, because they’ll end up getting rancid.

Is buying a dehydrator an absolute must?

Well, these devices do have two clear advantages: you don’t need to keep your eye on the oven for the four to 12 hours it takes to dry your foods, and you’ll consume a lot less electricity. Dehydrators also make controlling the temperature a snap. With ovens, it’s often impossible to even set the temperature below 150°F, whereas dehydrators are designed with exactly that in mind. Raw food enthusiasts can set the temperature to 115°F or less to comply with the limits set by raw food guidelines. In some cases, the drying time can be longer.

However, it is possible to dehydrate foods in the oven at a low temperature. Convection ovens are particularly suited to the task, as they are equipped with a fan that extracts moisture while circulating warm air. The process is simple: spread out the foods on a cookie sheet lined with parchment paper, put it in the oven at very low temperature while keeping the oven door open just enough to allow moisture to escape. Some people prefer to place foods directly on the oven rack, but that tends to make cleaning up a lot messier.

Home dehydrating opens up a whole range of enticing options that are original, varied and above all delicious. You can make protein-rich snacks like jerky from lean meats or thinly sliced marinated salmon.

Healthy versions of fruit leathers, which kids go crazy for, are also easy to make at home.

Combine four cups of seasonal fruits (apples or pears for example) with one tablespoon of lemon juice and one tablespoon of maple syrup or honey. It’s that easy! If you’re partial to cinnamon, add a teaspoon of it to the apple mix.

•Preheat the oven to 150°F (or 135°F if your oven lets you).
•Since you’ll need to puree the fruit, cut it into small pieces and add it to a food processor with the other ingredients (peeled or not, it’s up to you). You can also cook it with half a cup of water for 15 minutes to make it break down more easily. 
•Puree until smooth. It should be easy to spread, but not runny.
•Line two cookie sheets with parchment paper or silicone sheets. 
•Spread the puree on the cookie sheets around 3 to 6 mm (⅛ to ¼ inch) thick and as evenly as possible.
•Let dry in the oven for between six and 12 hours, until the leather is dry to the touch but not brittle. 
•Once you have taken the leather out of the oven but before it has completely cooled, place it on a new sheet of parchment paper. Cut into strips and roll. Tie each roll with a string or staple the paper (tape doesn’t stick to parchment paper). 
•Store in an airtight container or, ideally, in a vacuum-sealed bag. Avoid all contact with moisture; otherwise, the fruit leather will get mouldy. If you take it on an outing with you, don’t carry it with other foods.

In the peak of summer, when Ontario’s orchards bring us a bounty of stone fruits like peaches, plums and apricots, you’ll be well placed to take advantage of the low prices to make a huge stash of healthy snacks. In fact, the possibilities are limited only by the combinations your imagination can conjure up: strawberry-basil, ginger-peach, raspberry-mint... the list is endless!

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