Drying fruits and vegetables is a popular method of preserving produce with a long history. For years, people have dried fruits and vegetables in the outdoors or in ovens, but for commercial production, you can’t beat the consistency of a commercial dehydrator.
Like any food dehydration, some of the most important factors for safe drying of fruits and vegetables and the minimisation of spoilage due to mould and other bacteria are:
A commercial dehydrator allows you to control all three of these elements for a more consistent approach to drying fresh produce.
There’s a wide range of fruits and vegetables that can be successfully dehydrated. This includes:
Before you begin, it’s recommended to start with high-quality fresh produce1. Drying fruits and vegetables is not a way to make use of rotten or bruised fruit, but should be seen as a way to extend the life of fresh and ripe produce.
Step one is, of course, to wash your fruits and vegetables. It’s a good idea for people handing the produce to wear gloves and aprons, and take care not to break the skin of the produce to avoid contaminating the flesh.
The next step is to remove the peel, if appropriate. Some fruits or vegetables can be dehydrated with the peel on, but this can increase the dehydration time. If you wouldn’t normally eat the peel, it should definitely be removed. This is also the time to cut away any damaged parts of the produce.
Some fruits and vegetables are great to dehydrate whole, while others are best sliced. Remember, the thicker the slices or larger the pieces of fruit and vegetables are, the longer they will take to dehydrate. Try to cut pieces at the same thickness for a consistent drying time, and remember to cut away any blemishes that might spoil the final product.
Another option for dehydrated fruit is making fruit leathers. This involves pureeing fruit until smooth, usually with some lemon juice and an optional sweetener, then drying the puree on trays. In a dehydrator, fruit leather should be spread thinly and dried for around six to eight hours. It is done when no indentation is left when touched with a finger.
To preserve their colour and prevent browning, some fruits, like apples and pears, benefit from being treated with some kind of acid before dehydrating2. This can include the juice of acidic fruits like lemon juice or pineapple juice, but in a commercial environment, a more consistent result can be obtained by using citric acid or ascorbic acid.
If you are making vegetable chips3, some root vegetables, such as beetroot, will benefit from being blanched before dehydrating.
Another option some producers choose to use is sulphuring or sulphiting to preserve fruit colour. Sulphur-based methods are longer lasting than the other methods, but can cause reactions in some asthmatics, and some consumers prefer naturally dried fruits.
Let’s take a look at each of these methods:
Drying times will vary greatly between fruits and vegetables. Of course, factors like the size of the produce, whole pieces vs slices, and the preparation and soaking methods used will all result in variations in drying time.
When loading the trays of your dehydrator, ensure to give each piece plenty of space – there should be no touching or overlapping. This is because consistent air flow around the produce is one of the critical factors to successful dehydration.
There are many resources online4 with timing guidelines for various types of produce5 and these can be used as a starting point in gauging the likely dehydration timeline. It’s important to note that food dries much faster towards the end of the drying time, so it’s important to watch it closely.
Whatever drying method you are using, you are generally looking for about a 20 percent moisture content for dried fruits and as little as 10 percent moisture content for dried vegetables. Vegetables are usually dehydrated further as they are often rehydrated before eating, like beans and pulses.
Some tests for dryness include:
Once your fruits and vegetables are dried, they need to be cooled and then packaged to avoid moisture re-entering the produce. It’s important that everything is fully cooled, otherwise the produce could sweat and create moisture build up.
Another important step, particularly for dried fruit, is conditioning prior to packaging. Sometimes the remaining moisture may not be evenly distributed among the pieces of fruit, so conditioning is used to equalise this in order to prevent mould.
Conditioning4 involves packing the dried fruit in sealed containers for seven to ten days. Shake the containers daily and check for condensation – if condensation does form, the fruit is inadequately dried and must return to the dehydrator. As vegetables are usually dried to a lower moisture level, they do not require conditioning.
After conditioning, the fruit is ready to be packaged and stored.
There are various packaging products6 available to safely store your dried produce7 and prolong the shelf life. Factors to consider include durability, tear resistance, how the product will be displayed at the point of sale and, of course, resistance to moisture. Air tight packaging is essential to protect your carefully dehydrated products from air, humidity, odours and moisture.
Including an oxygen scavenger (moisture absorber) is not compulsory for dried fruits and vegetables, but is something you may like to consider.
We’ve got a great range of commercial dehydrators to suit new businesses, growing businesses and established businesses. Explore our products and get in touch if you need help choosing the right dehydrator for your needs.