Washing Potatoes with Clean Water

Published online: Feb 23, 2022 Articles, New Products
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Washing potatoes with clean water improves their shelf life and raises the product value. That allows the potatoes to be exported to distant destinations with fewer issues. Primofin has developed a washing line for just such a purpose and, together with VAM WaterTech, has set up an integrated water treatment plant that means the process water can be completely cleaned and reused.

Dutch company Primofin has been cultivating, processing and trading fruit and vegetables since 1975. In 2013, they switched to concentrate completely on washing, sorting and packaging potatoes for the French fry industry, the catering industry, retail and export. Primofin’s potatoes find their way to shops at home and abroad via wholesalers and exporters. On top of that, the company assists other packers when their own capacity is insufficient.

“We’ve actually got two lines of our own for washing potatoes,” says Jan Vroegop, who runs the company with Wim Murre. “The industrial line is for washing, salting and electronically scanning potatoes for French fries. It has a high capacity for processing potatoes in bulk, removing soil, stones, clods, clay caps, pathogens and so on. Because we were getting more and more demand for washing potatoes for destinations farther afield, we developed and built a separate export line for that.”

After washing, sorting and packaging, the cleaned and dried potatoes are packed into crates, Big Bags, net bags, paper bags or foil, depending on what the customer wants.

Product-Friendly, Hygienic Cleaning

The export line has a capacity of 30 tons per hour and is intended for washing, drying, electronic scanning and sorting of potatoes for the catering and retail sectors at home and abroad, as well as for export overseas.

“We’re then talking potatoes that genuinely need a long shelf life after washing,” says Vroegop. “The product is sometimes on the road for weeks. The right quality can only be guaranteed if the potatoes are cleaned in a product-friendly and hygienic way.”

As Primofin had already had positive experiences with a washing line for the processing industry, the company decided to build its own line for the fresh produce market as well.

“We particularly took account of product-friendly treatment to protect potatoes and low-maintenance machinery, and we wanted the entire line in one building,” Vroegop says. “The washing line has now been running for quite some time, and we’re noticing that more and more exporters can see the added value of washing potatoes with clean and hygienic water.”

How the Process Works

Loose soil, stones and clods are first removed from the potatoes before they are washed. The foliage is then separated, and the potatoes go through a washing chute for cleaning. They then go over a set of brush rollers, where they are finally sprayed with drinking water. After washing, the potatoes are electronically scanned, sorted and packed, and the water goes to the VAM water purification plant. The water purification system first removes the coarse particles from the water, the smaller particles clump together along with any pathogens thanks to additives (electric charge) and are then removed, and the cleaned water is pumped back into the washing line. This means the water in the washing line is reused in a cycle.

Primofin’s export line has its own water supply, a purification system from VAM WaterTech, a company that develops water purification solutions for fruit and vegetable processing and packing, leading to safer and cleaner fruit and vegetable products and allowing producers to use water economically and sustainably.

“Washing potatoes uses a lot of water, and the quality of the water isn’t always very good,” says Eduard van Antwerpen of VAM WaterTech. “Cross-contamination is a real risk and an obstacle to the quality of the product. The assumption is often that potatoes end up in consumers’ kitchens straight after washing, but that isn’t the case, of course. If you want to guarantee longer shelf life, it’s particularly important to prevent cross-contamination.”

Closed System Cuts Water Consumption

According to van Antwerpen, the system’s strength is the combination of water purification and a closed system. The purification solution from VAM WaterTech makes is possible to completely purify the water again.

“You could compare it to taking a shower instead of having a bath, with the major difference that the water in this washing line doesn’t get rinsed away,” he says. “Our water purification consists of a continuous flow of clean water, a closed-cycle process that can save up to 95% of the process water.”

A continuous flow of 75 cubic meters per hour is provided, with minimal losses. Drinking water is, however, added at the end of the washing line, as that is also required by law.

Van Antwerpen believes washing potatoes with clean water makes a huge difference. “The water is often seen as a nuisance, but water quality has a big influence on the final product,” he says. “Early potato varieties in particular are susceptible to cross-contamination. Washing potatoes with clean water really does add value. We’re seeing potatoes for the fresh produce market that are still top-quality after six to eight weeks, and for seed potatoes we’re even seeing a good shelf life of up to three months. It all makes it possible to export to faraway destinations without problems, which in turn opens up new sales opportunities.”

Know What You’re Shipping

Virtually all potatoes for the consumer market are washed beforehand, for reasons that include phytosanitary requirements.

“Another big plus is that you can see the pure product after washing, which helps the sorting process. It means you really know what you’re shipping,” Vroegop says. “And you want to be sure of that, particularly now that transport costs are skyrocketing. Our washing line means we can take a lot of work out of the exporters’ hands and guarantee that what we do is done right. The quality of the water is checked regularly, as required, and VAM WaterTech uses a remote monitoring system to keep an eye on the water quality continuously. If necessary, it is possible to trace what the water quality was for each batch of potatoes. We’re proving that we can ship potatoes as far as Singapore and Hong Kong without their shelf life being affected.”

Visit www.vam-watertech.com to learn more.