Thanks to VaccTek, our onions have never been this dry!

Ajuin is no longer dependent on the weather, thanks to VaccTek

Here the results drying onions with VaccTek

Picture taken just before the harvest

4 days later, after harvesting, grading and drying with VaccTek

Jan van der Spek: "Our onions have never been this dry at this time of year"

Raining in the north or raining in the tropics

With condense drying, your onions can be kept dry all year round

Over the last year, onion sorting and packaging company Ajuin from Moerkapelle has expanded its facilities with a new 1,250 sqm warehouse that has the capacity to store 2,000 tonnes of onions in boxes. The company, belonging to brothers Johan, Paul and Jan van der Spek, opted for the installation of three AgroVent VaccTek units, after seeing this storage technique in action in Denmark. The VaccTek units have been built into the back wall of the box storage facility. Jan van der Spek highly praises the technique: Our onions have never been this dry at this time of year.

A VaccTek unit, built into the back wall of the onion storage facility

Only four people work full time at Ajuin, and the company works well like this. "We couldn't do this if we were to export the onions ourselves, as this would require someone in the office at all times. We simply focus on storing, sorting and packaging, and provide exporters with packaged brown, red and organic onions, varying from 1 kilo bags to big sacks," says Jan. He believes working with few staff in a family company is a big advantage. It makes us flexible. If we aren't making money, we take things steady, and when it's busy we work harder.

The VaccTek technique dries the onions whatever the weather conditions. Condensation drying isn't a new technique, but AgroVent was the first firm to succeed in making it widely accessible for storing potatoes and onions. "The importance of being able to dry onions well is becoming increasingly clearer each season. A wetter and warmer climate and the reduction of chemicals is making it more and more difficult to store onions whilst minimising rot and losses. An essential solution is heating the air used to dry the product, which is mainly done with gas heaters at present," says Huub Kasius of AgroVent.

Three VaccTek units in a row to condense dry the onion crop

"But using gas to heat has some downsides. First of all, it's expensive. To keep fungi and bacteria at bay, ideally you need to dry at 30 degrees or above. Due to heating costs, a lot of people work at a maximum of 20 degrees, which isn't high enough for red onions, for instance. Burning gas also adds moisture to the warehouse. Every kilogram of gas burned produces 1.6 kg of water. The warm, slightly moist air can cause extra condensation or moisture spots in the boxes. Almost 10% of the gas usage is needed to remove the water created by burning. It is also inefficient, as a lot of the valuable heat escapes through the hatches. The drying result is also strongly influenced by outdoor air conditions," continues Huub.

VaccTek has found a solution to this, by creating a completely new way of drying and storing. Regardless of outdoor conditions, and without the use of gas, drying times are 50% shorter, and use up to 80% less energy. "It makes your company more secure, and keeps quality high. During the harvest in particular, we can now dry the onions much more quickly. In previous years, the onions would sometimes arrive from the field at a temperature of 20-25 degrees and with an air humidity of 90%. Now we can dry it at full speed without gas," says Jan van der Spek.

VaccTek can drain up to 160 litres of water per hour

The results of the VaccTek are easy to see, as the water flows away during wet conditions. "With VaccTek, up to 160 litres of water can be drained away per hour," says Jan. It is a fully integrated system, which he sees as an enormous advantage. "We don't use many refrigerants. Storage is still controlled and regulated using the storage computer, which allows for maximal control. We also utilise all of the heat produced during condensation. All energy that is released is used to heat the onions."

"We also store an increasing volume of organic onions. Storage is even tighter for organic onions, and we are already seeing a fall in rejected produce. We can dry out the rotten onions, for instance. In previous years, it was difficult to dry properly after a dry October and wet November. Now as soon as the door closes, the onions dry out rapidly. It comes with a price tag, but I believe it's the future," concludes Jan.