Best practice for drying fruit and vegetables

Commercially producing dried fruits and vegetables

Best practice tips for drying fruit and vegetables

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:

• Humidity
• Temperature
• Air flow

A commercial dehydrator allows you to control all three of these elements for a more consistent approach to drying fresh produce.

Choosing your fruits and vegetables

There’s a wide range of fruits and vegetables that can be successfully dehydrated. This includes:

• Bigger fruits like apples, pears, apricots, peaches, mangoes and pineapple.
• Berries like strawberries, blueberries and raspberries.
• Citrus like oranges, lemons, limes and grapefruits – great for garnishing cocktails or decorating cakes!
• Vegetable chips with sweet potato, kale, beetroot and more.
• Other vegetables can also be dehydrated to increase their lifespan and be rehydrated before cooking and consuming.

How to prepare fruits and vegetables for dehydrating

Before you begin, it’s recommended to start with high-quality fresh produce.¹ 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.

Further preservation approaches: Blanching, sugaring, acid baths and sulphuring

To preserve their colour and prevent browning, some fruits, like apples and pears, benefit from being treated with some kind of acid before dehydrating.² 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 chips,³ 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:

• Sugaring: This involves soaking fruits in a sugar syrup for up to 18 hours, before removing the excess and drying
• Sulphuring: Sulphur is ignited and burned in an enclosed box with the fruit
• Sulphite dips: Sodium bisulphite, sodium sulphite or sodium meta-bisulphite are dissolved in water and used as a fruit soak
• Ascorbic acid: Ascorbic acid (vitamin C) is dissolved in water and used as a soaking liquid to reduce browning
• Fruit juice dip: A juice high in vitamin C like lemon juice or pineapple juice can be used instead of an ascorbic acid mix
• Steam blanching: Fruit and vegetables can be steamed over boiling water, but this can change the flavour and texture
• Water blanching: Place vegetables in water than has been brought to a rolling boil – times vary based on the vegetable. Some fruits, for example blueberries, need to have their skin cracked in boiling water before dehydrating.