July 14, 2016

Ethylene storage technique proves good frying color

A group of growers has studied, tested a new storage technique with ethylene gas. Now this technique is well known in potato and onion storage under the name Restrain. This technique was always promoted with restraint for the storage of processing potatoes – unlike for the table potatoes – due to the scepticism over accelerated development of sugars due to the ethylene, which would cause the potatoes to color too darkly during the frying process. Research by the Potato Council now shows that the frying color remains good. “A break through, after four years of research,” Dirk Garos responds enthusiastically.


“If you store potatoes, they gradually form sugars, as the starch is turned into sugar. Everyone was afraid that ethylene would accelerate the increase in sugars, which would make them too dark during the frying process. For chip factories and fast food restaurants this is a disaster, as they only want the so called ‘golden fries’. The result of this research is therefore the start of an important ‘game-change'”, continues Dirk. “The much used CIPC methods with Chloropropham have been on the market for decades, but are increasingly pressured due to the residues present. Ethylene is a good alternative, without residue, easy to apply and even a lot cheaper. All other alternatives are three to five times as expensive.”

“An added advantage of ethylene is that you aren’t bothered by internal sprouting. Unlike CIPC methods this is impossible, as ethylene works in the opposite way. Ethylene blocks cell elongation, but cell division continue. Researcher Glyn Harper concludes in the research that in a sprout prone year it is sensible to apply a low dose of CIPC methods when they are initially harvested, but to only use ethylene for the rest of the season,” continues Dirk. “With the evidence that we have now, a huge market in industry potatoes is created. We already see growers in Scandinavia and Russia switch completely, but we also expect chip factories in other markets to switch, as buyers are becoming increasingly cautious due to the residues on the CIPC substances. A few large players in chips are already scaling up ethylene!”

— Dirk Garos, Restrain

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