Preserving food when plentiful, to prepare for leaner times, is an ancient practice. There’s evidence cultures in the Middle East and China were using the sun and wind to preserve food such as fish, meat, fruit and vegetables, as far back as 12,000 years ago.
Widely use by combat troops during World War II, dehydrated food, unsurprisingly, fell out of favour with the public after the war. It wasn’t until the cultural revolution of the 1960’s, with a renewed focus on all things natural, that dehydrating foods experienced a renaissance of sorts.
As with all food preservation methods, there are certain steps along the way that present safety issues. Sourcing, producing and storing dehydrated fruits, vegetables and other produce correctly is important. It keeps the food, and the humans who consume it, safe.
Dehydrated food is cool again. You only need to check the fruit, veggie and health food aisles. People are living busy lives and want portable, tasty and healthy snacks. And not just snacks. Meals resembling grazing tables are almost the norm in some homes and offices around the world.
With the seemingly endless array of food and diet fads, if people can’t make their own food, they want to know what goes into the foods they do buy.
So, it goes without saying, that means sourcing quality produce.
There’s never been a better time to support local business and buy locally grown, seasonal produce as often as possible. Farmers’ Markets are a great place to start and with the Farmers Weekly1 reporting there’s 650 farmer’s markets in the UK, you shouldn’t have any trouble finding one nearby.
Buying in season means you’re:
Not sure what’s in season? Check out this brilliant (and downloadable) Seasonal Guide2 to British fruit and veg to see what’s in season all year round.
It may come as a surprise to learn we imported approximately £5.44 billion of fruit and veg3 in the first six months of 2018 alone. This came from all across the globe with 19% coming from Spain, 11% from the Netherlands and 5% from South Africa.
To protect Britain, there’s strict regulations around the importation of fresh produce for commercial purposes4.
‘Imports of fruit and vegetables (whether fresh, dried, tinned, processed or frozen) from outside the European Union (EU) must meet the same standards of hygiene and go through the same safety procedures as food produced in the EU. You do not normally need a health certificate to import fruit and vegetables.’
Read more about importing food products for personal use5.
The UK has left the EU and while the transition period comes ends at the end of 2020, importers of fruit and vegetables to the UK6 are advised:
If you import EU fruit and vegetables into the UK, marketing standards processes at UK borders will not change in the short term from 1 January 2021.
If you import fresh fruit and vegetables that originate within the EU, or third country goods which have cleared customs in the EU, you will not need to apply for a UK-issued certificate of conformity ahead of them arriving into the UK.
To ensure that EU fruits and vegetables entering the UK market are of high quality and comply with UK marketing standards, additional compliance checks will be carried out by:
They will not carry out marketing standards checks at the border.
As these are short term measures, we suggest you check regularly for updates and changes to regulations.
The Cold Chain Federation10 is the trade body that has represented the UK temperature controlled storage and distribution industry for more than a century. The federation helps maintain the safety and quality of food products as they’re handled, transported and stored. As it says:
‘From raw materials, through manufacturing, storage, distribution and retail the cold chain keeps goods safe and prevents waste. As such it underpins key industries and our way of life.’
That leaves a lot of room for contamination as the produce moves from paddock to plate.
While there’s not one temperature to suit all fruit and veg, there are some optimum storage temperatures that can be applied as a general ‘rule of thumb’:
Those in the cold chain should also regularly review policies and operating procedures as part of Hazard Analysis Critical Control Points (HACCP) and internal Food Safety Programs.
Originally developed by NASA and a group of food safety specialists in the ‘60s, Hazard Analysis Critical Control Point (HACCP) is an internationally recognised food safety and risk assessment plan. The plan outlines seven key principles in food safety:
UK food businesses can use MyHACCP11 to develop a food safety plan based on HACCP principles. It’s online and free to use.
Some fruits, such as apples, bananas, nectarines, pears, peaches and apricots will benefit from some pre-treatment before drying. Pre-treating with an acidic solution like citric acid or ascorbic acid will:
Other methods of pre-treating are:
The drying process removes moisture from the food. This also hinders the growth of mould, bacteria and yeast. This ensures the dehydrated fruit and vegetables don’t easily spoil.
A major contributor to drying food is humidity. As drying involves removing the moisture from the food and releasing it into the surrounding air, low humidity helps the drying process. This is why the drying of foods originated in the warmer and drier countries around the planet. Higher humidity will slow down the drying process as the air would also be heavy with moisture. Increasing air flow can speed up the drying process.
Water activity (aw) is a measure of available water in food. That’s not as simple as how much water is in the food though, as some water is bound to other ingredients – like sugar or salt – and isn’t available. In the context of dehydration, this is important as it is the available water12 that microorganisms will use to facilitate growth.
When too much water is available, microorganisms can grow. Pure water has aw = 1.00 and fresh fruits and vegetables have aw = 0.98. Public Health England13 recommends drying fruits to aw = 0.60 to 0.85 and drying vegetables to aw = <0.60.
The safest and most accurate way to monitor water activity is by using a water activity meter. It is also possible to measure weight loss to determine moisture loss, but this is not recommended for commercial applications.
If you import, pack, distribute or sell fruit or veg, you must follow quality and labelling rules and you may be inspected without notice.
The GOV.UK14 site advises:
Anyone who markets fresh fruit or vegetables, salad crops, nuts or cultivated mushrooms must meet the rules on quality and labelling.
There are 2 sets of marketing standards:
The rules are detailed, and retailers should make sure you understand and follow the advice in the EU Marketing Standards for Fresh Horticultural Produce - A Guide for Retailers7 (PDF, 2.8MB, 12 pages) or A Guide for Retailers in Wales15 (PDF, 2MB, 12 pages) - so that you meet the legal requirements.
The FSA4 suggests, for advice on the labelling of specific products, please contact your local authority’s Trading Standards Department or Environmental Health Department16.
Correctly prepared, dehydrated and stored dried fruits and vegetables typically last a year or even longer. Vegetables tend to have a longer shelf life than fruit. Stored at stable temperatures in a cool, dark spot will increase their shelf life. Those foods with the least moisture content will last the longest and vegetables that are cooked prior to dehydration tend to last longer as well.
Should a package show condensation or other signs of moisture, if it looks unusual or smells funny, it’s likely to have spoiled. And if it’s mouldy, chuck it in the bin.
There’s a few basic principles to adhere to in any environment where meat and food products are being prepared. These include:
The highest hygiene standards should be maintained every step of the way.
Best practice is to clean it between every batch. The trays in our dehydrators are dishwasher safe and the insides of the dehydrator should be cleaned using a cloth and warm soapy water (being careful not to splash water onto the electrical parts). We recommend using a food-safe sanitiser spray to eliminate microbial growth.
Any cleaning chemicals should be appropriately stored. Staff should be trained how to use cleaning chemicals safely, so as not to cause accidents or contaminate foods.
It’s also important to ensure equipment is thoroughly dried after cleaning to prevent Listeria contamination.
As well as daily cleaning, including throughout the day, regular cleaning and sanitising should be scheduled for things like cool rooms and drains. It’s also a good idea to regularly clean shelving in chillers, door handles, door seals, switches.
All equipment used for monitoring should be regularly checked and calibrated to ensure accuracy. This includes:
If you’ve any questions about cleaning your commercial dehydrator, recommended settings, or other aspects to ensure a safe final product, let us know. We’re here to help guide you to producing dehydrated foods that are delicious and healthy.